Fixed MTP to work with TWRP

drivers/cpuidle/Kconfig

@@ -0,0 +1,59 @@
+menu "CPU Idle"
+
+config CPU_IDLE
+	bool "CPU idle PM support"
+	default y if ACPI || PPC_PSERIES
+	select CPU_IDLE_GOV_LADDER if (!NO_HZ && !NO_HZ_IDLE)
+	select CPU_IDLE_GOV_MENU if (NO_HZ || NO_HZ_IDLE)
+	help
+	  CPU idle is a generic framework for supporting software-controlled
+	  idle processor power management.  It includes modular cross-platform
+	  governors that can be swapped during runtime.
+
+	  If you're using an ACPI-enabled platform, you should say Y here.
+
+if CPU_IDLE
+
+config CPU_IDLE_MULTIPLE_DRIVERS
+        bool
+
+config CPU_IDLE_GOV_LADDER
+	bool "Ladder governor (for periodic timer tick)"
+	default y
+
+config CPU_IDLE_GOV_MENU
+	bool "Menu governor (for tickless system)"
+	default y
+
+config DT_IDLE_STATES
+	bool
+
+config CPU_IDLE_STOP_IDLE_DURING_HOTPLUG
+	bool "Stop idle during hotplug in/out"
+	depends on CPU_IDLE && HOTPLUG_CPU
+
+menu "ARM CPU Idle Drivers"
+depends on ARM
+source "drivers/cpuidle/Kconfig.arm"
+endmenu
+
+menu "ARM64 CPU Idle Drivers"
+depends on ARM64
+source "drivers/cpuidle/Kconfig.arm64"
+endmenu
+
+menu "MIPS CPU Idle Drivers"
+depends on MIPS
+source "drivers/cpuidle/Kconfig.mips"
+endmenu
+
+menu "POWERPC CPU Idle Drivers"
+depends on PPC
+source "drivers/cpuidle/Kconfig.powerpc"
+endmenu
+
+endif
+
+config ARCH_NEEDS_CPU_IDLE_COUPLED
+	def_bool n
+endmenu

drivers/cpuidle/Kconfig.arm

@@ -0,0 +1,65 @@
+#
+# ARM CPU Idle drivers
+#
+config ARM_BIG_LITTLE_CPUIDLE
+	bool "Support for ARM big.LITTLE processors"
+	depends on ARCH_VEXPRESS_TC2_PM || ARCH_EXYNOS
+	depends on MCPM
+	select ARM_CPU_SUSPEND
+	select CPU_IDLE_MULTIPLE_DRIVERS
+	select DT_IDLE_STATES
+	help
+	  Select this option to enable CPU idle driver for big.LITTLE based
+	  ARM systems. Driver manages CPUs coordination through MCPM and
+	  define different C-states for little and big cores through the
+	  multiple CPU idle drivers infrastructure.
+
+config ARM_CLPS711X_CPUIDLE
+	bool "CPU Idle Driver for CLPS711X processors"
+	depends on ARCH_CLPS711X || COMPILE_TEST
+	help
+	  Select this to enable cpuidle on Cirrus Logic CLPS711X SOCs.
+
+config ARM_HIGHBANK_CPUIDLE
+	bool "CPU Idle Driver for Calxeda processors"
+	depends on ARM_PSCI
+	select ARM_CPU_SUSPEND
+	help
+	  Select this to enable cpuidle on Calxeda processors.
+
+config ARM_KIRKWOOD_CPUIDLE
+	bool "CPU Idle Driver for Marvell Kirkwood SoCs"
+	depends on MACH_KIRKWOOD
+	help
+	  This adds the CPU Idle driver for Marvell Kirkwood SoCs.
+
+config ARM_ZYNQ_CPUIDLE
+	bool "CPU Idle Driver for Xilinx Zynq processors"
+	depends on ARCH_ZYNQ
+	help
+	  Select this to enable cpuidle on Xilinx Zynq processors.
+
+config ARM_U8500_CPUIDLE
+	bool "Cpu Idle Driver for the ST-E u8500 processors"
+	depends on ARCH_U8500
+	help
+	  Select this to enable cpuidle for ST-E u8500 processors
+
+config ARM_AT91_CPUIDLE
+	bool "Cpu Idle Driver for the AT91 processors"
+	default y
+	depends on ARCH_AT91
+	help
+	  Select this to enable cpuidle for AT91 processors
+
+config ARM_EXYNOS_CPUIDLE
+	bool "Cpu Idle Driver for the Exynos processors"
+	depends on ARCH_EXYNOS
+	help
+	  Select this to enable cpuidle for Exynos processors
+
+config ARM_MVEBU_V7_CPUIDLE
+	bool "CPU Idle Driver for mvebu v7 family processors"
+	depends on ARCH_MVEBU
+	help
+	  Select this to enable cpuidle on Armada 370, 38x and XP processors.

drivers/cpuidle/Kconfig.arm64

@@ -0,0 +1,23 @@
+#
+# ARM64 CPU Idle drivers
+#
+
+config ARM64_CPUIDLE
+	bool "Generic ARM64 CPU idle Driver"
+	select ARM64_CPU_SUSPEND
+	select DT_IDLE_STATES
+	help
+	  Select this to enable generic cpuidle driver for ARM64.
+	  It provides a generic idle driver whose idle states are configured
+	  at run-time through DT nodes. The CPUidle suspend backend is
+	  initialized by calling the CPU operations init idle hook
+	  provided by architecture code.
+
+config ARM64_EXYNOS_CPUIDLE
+	bool "Cpu Idle Driver for the ARM64 Exynos processors"
+	depends on ARCH_EXYNOS
+	select ARM64_CPU_SUSPEND
+	select CPU_IDLE_MULTIPLE_DRIVERS
+	select DT_IDLE_STATES
+	help
+	  Select this to enable cpuidle for ARM64 Exynos processors.

drivers/cpuidle/Kconfig.mips

@@ -0,0 +1,17 @@
+#
+# MIPS CPU Idle Drivers
+#
+config MIPS_CPS_CPUIDLE
+	bool "CPU Idle driver for MIPS CPS platforms"
+	depends on CPU_IDLE && MIPS_CPS
+	depends on SYS_SUPPORTS_MIPS_CPS
+	select ARCH_NEEDS_CPU_IDLE_COUPLED if MIPS_MT
+	select GENERIC_CLOCKEVENTS_BROADCAST if SMP
+	select MIPS_CPS_PM
+	default y
+	help
+	  Select this option to enable processor idle state management
+	  through cpuidle for systems built around the MIPS Coherent
+	  Processing System (CPS) architecture. In order to make use of
+	  the deepest idle states you will need to ensure that you are
+	  also using the CONFIG_MIPS_CPS SMP implementation.

drivers/cpuidle/Kconfig.powerpc

@@ -0,0 +1,20 @@
+#
+# POWERPC CPU Idle Drivers
+#
+config PSERIES_CPUIDLE
+	bool "Cpuidle driver for pSeries platforms"
+	depends on CPU_IDLE
+	depends on PPC_PSERIES
+	default y
+	help
+	  Select this option to enable processor idle state management
+	  through cpuidle subsystem.
+
+config POWERNV_CPUIDLE
+	bool "Cpuidle driver for powernv platforms"
+	depends on CPU_IDLE
+	depends on PPC_POWERNV
+	default y
+	help
+	  Select this option to enable processor idle state management
+	  through cpuidle subsystem.

drivers/cpuidle/Makefile

@@ -0,0 +1,33 @@
+#
+# Makefile for cpuidle.
+#
+
+obj-y += cpuidle.o driver.o governor.o sysfs.o governors/
+obj-$(CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED) += coupled.o
+obj-$(CONFIG_DT_IDLE_STATES)		  += dt_idle_states.o
+
+##################################################################################
+# ARM SoC drivers
+obj-$(CONFIG_ARM_MVEBU_V7_CPUIDLE) += cpuidle-mvebu-v7.o
+obj-$(CONFIG_ARM_BIG_LITTLE_CPUIDLE)	+= cpuidle-big_little.o
+obj-$(CONFIG_ARM_CLPS711X_CPUIDLE)	+= cpuidle-clps711x.o
+obj-$(CONFIG_ARM_HIGHBANK_CPUIDLE)	+= cpuidle-calxeda.o
+obj-$(CONFIG_ARM_KIRKWOOD_CPUIDLE)	+= cpuidle-kirkwood.o
+obj-$(CONFIG_ARM_ZYNQ_CPUIDLE)		+= cpuidle-zynq.o
+obj-$(CONFIG_ARM_U8500_CPUIDLE)         += cpuidle-ux500.o
+obj-$(CONFIG_ARM_AT91_CPUIDLE)          += cpuidle-at91.o
+obj-$(CONFIG_ARM_EXYNOS_CPUIDLE)        += cpuidle-exynos.o
+
+###############################################################################
+# MIPS drivers
+obj-$(CONFIG_MIPS_CPS_CPUIDLE)		+= cpuidle-cps.o
+
+###############################################################################
+# ARM64 drivers
+obj-$(CONFIG_ARM64_CPUIDLE)		+= cpuidle-arm64.o
+obj-$(CONFIG_ARM64_EXYNOS_CPUIDLE)      += cpuidle-exynos64.o cpuidle_profiler.o
+
+###############################################################################
+# POWERPC drivers
+obj-$(CONFIG_PSERIES_CPUIDLE)		+= cpuidle-pseries.o
+obj-$(CONFIG_POWERNV_CPUIDLE)		+= cpuidle-powernv.o

drivers/cpuidle/coupled.c

@@ -0,0 +1,794 @@
+/*
+ * coupled.c - helper functions to enter the same idle state on multiple cpus
+ *
+ * Copyright (c) 2011 Google, Inc.
+ *
+ * Author: Colin Cross <ccross@android.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ */
+
+#include <linux/kernel.h>
+#include <linux/cpu.h>
+#include <linux/cpuidle.h>
+#include <linux/mutex.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+
+#include "cpuidle.h"
+
+/**
+ * DOC: Coupled cpuidle states
+ *
+ * On some ARM SMP SoCs (OMAP4460, Tegra 2, and probably more), the
+ * cpus cannot be independently powered down, either due to
+ * sequencing restrictions (on Tegra 2, cpu 0 must be the last to
+ * power down), or due to HW bugs (on OMAP4460, a cpu powering up
+ * will corrupt the gic state unless the other cpu runs a work
+ * around).  Each cpu has a power state that it can enter without
+ * coordinating with the other cpu (usually Wait For Interrupt, or
+ * WFI), and one or more "coupled" power states that affect blocks
+ * shared between the cpus (L2 cache, interrupt controller, and
+ * sometimes the whole SoC).  Entering a coupled power state must
+ * be tightly controlled on both cpus.
+ *
+ * This file implements a solution, where each cpu will wait in the
+ * WFI state until all cpus are ready to enter a coupled state, at
+ * which point the coupled state function will be called on all
+ * cpus at approximately the same time.
+ *
+ * Once all cpus are ready to enter idle, they are woken by an smp
+ * cross call.  At this point, there is a chance that one of the
+ * cpus will find work to do, and choose not to enter idle.  A
+ * final pass is needed to guarantee that all cpus will call the
+ * power state enter function at the same time.  During this pass,
+ * each cpu will increment the ready counter, and continue once the
+ * ready counter matches the number of online coupled cpus.  If any
+ * cpu exits idle, the other cpus will decrement their counter and
+ * retry.
+ *
+ * requested_state stores the deepest coupled idle state each cpu
+ * is ready for.  It is assumed that the states are indexed from
+ * shallowest (highest power, lowest exit latency) to deepest
+ * (lowest power, highest exit latency).  The requested_state
+ * variable is not locked.  It is only written from the cpu that
+ * it stores (or by the on/offlining cpu if that cpu is offline),
+ * and only read after all the cpus are ready for the coupled idle
+ * state are are no longer updating it.
+ *
+ * Three atomic counters are used.  alive_count tracks the number
+ * of cpus in the coupled set that are currently or soon will be
+ * online.  waiting_count tracks the number of cpus that are in
+ * the waiting loop, in the ready loop, or in the coupled idle state.
+ * ready_count tracks the number of cpus that are in the ready loop
+ * or in the coupled idle state.
+ *
+ * To use coupled cpuidle states, a cpuidle driver must:
+ *
+ *    Set struct cpuidle_device.coupled_cpus to the mask of all
+ *    coupled cpus, usually the same as cpu_possible_mask if all cpus
+ *    are part of the same cluster.  The coupled_cpus mask must be
+ *    set in the struct cpuidle_device for each cpu.
+ *
+ *    Set struct cpuidle_device.safe_state to a state that is not a
+ *    coupled state.  This is usually WFI.
+ *
+ *    Set CPUIDLE_FLAG_COUPLED in struct cpuidle_state.flags for each
+ *    state that affects multiple cpus.
+ *
+ *    Provide a struct cpuidle_state.enter function for each state
+ *    that affects multiple cpus.  This function is guaranteed to be
+ *    called on all cpus at approximately the same time.  The driver
+ *    should ensure that the cpus all abort together if any cpu tries
+ *    to abort once the function is called.  The function should return
+ *    with interrupts still disabled.
+ */
+
+/**
+ * struct cpuidle_coupled - data for set of cpus that share a coupled idle state
+ * @coupled_cpus: mask of cpus that are part of the coupled set
+ * @requested_state: array of requested states for cpus in the coupled set
+ * @ready_waiting_counts: combined count of cpus  in ready or waiting loops
+ * @online_count: count of cpus that are online
+ * @refcnt: reference count of cpuidle devices that are using this struct
+ * @prevent: flag to prevent coupled idle while a cpu is hotplugging
+ */
+struct cpuidle_coupled {
+	cpumask_t coupled_cpus;
+	int requested_state[NR_CPUS];
+	atomic_t ready_waiting_counts;
+	atomic_t abort_barrier;
+	int online_count;
+	int refcnt;
+	int prevent;
+};
+
+#define WAITING_BITS 16
+#define MAX_WAITING_CPUS (1 << WAITING_BITS)
+#define WAITING_MASK (MAX_WAITING_CPUS - 1)
+#define READY_MASK (~WAITING_MASK)
+
+#define CPUIDLE_COUPLED_NOT_IDLE	(-1)
+
+static DEFINE_MUTEX(cpuidle_coupled_lock);
+static DEFINE_PER_CPU(struct call_single_data, cpuidle_coupled_poke_cb);
+
+/*
+ * The cpuidle_coupled_poke_pending mask is used to avoid calling
+ * __smp_call_function_single with the per cpu call_single_data struct already
+ * in use.  This prevents a deadlock where two cpus are waiting for each others
+ * call_single_data struct to be available
+ */
+static cpumask_t cpuidle_coupled_poke_pending;
+
+/*
+ * The cpuidle_coupled_poked mask is used to ensure that each cpu has been poked
+ * once to minimize entering the ready loop with a poke pending, which would
+ * require aborting and retrying.
+ */
+static cpumask_t cpuidle_coupled_poked;
+
+/**
+ * cpuidle_coupled_parallel_barrier - synchronize all online coupled cpus
+ * @dev: cpuidle_device of the calling cpu
+ * @a:   atomic variable to hold the barrier
+ *
+ * No caller to this function will return from this function until all online
+ * cpus in the same coupled group have called this function.  Once any caller
+ * has returned from this function, the barrier is immediately available for
+ * reuse.
+ *
+ * The atomic variable must be initialized to 0 before any cpu calls
+ * this function, will be reset to 0 before any cpu returns from this function.
+ *
+ * Must only be called from within a coupled idle state handler
+ * (state.enter when state.flags has CPUIDLE_FLAG_COUPLED set).
+ *
+ * Provides full smp barrier semantics before and after calling.
+ */
+void cpuidle_coupled_parallel_barrier(struct cpuidle_device *dev, atomic_t *a)
+{
+	int n = dev->coupled->online_count;
+
+	smp_mb__before_atomic();
+	atomic_inc(a);
+
+	while (atomic_read(a) < n)
+		cpu_relax();
+
+	if (atomic_inc_return(a) == n * 2) {
+		atomic_set(a, 0);
+		return;
+	}
+
+	while (atomic_read(a) > n)
+		cpu_relax();
+}
+
+/**
+ * cpuidle_state_is_coupled - check if a state is part of a coupled set
+ * @dev: struct cpuidle_device for the current cpu
+ * @drv: struct cpuidle_driver for the platform
+ * @state: index of the target state in drv->states
+ *
+ * Returns true if the target state is coupled with cpus besides this one
+ */
+bool cpuidle_state_is_coupled(struct cpuidle_device *dev,
+	struct cpuidle_driver *drv, int state)
+{
+	return drv->states[state].flags & CPUIDLE_FLAG_COUPLED;
+}
+
+/**
+ * cpuidle_coupled_set_ready - mark a cpu as ready
+ * @coupled: the struct coupled that contains the current cpu
+ */
+static inline void cpuidle_coupled_set_ready(struct cpuidle_coupled *coupled)
+{
+	atomic_add(MAX_WAITING_CPUS, &coupled->ready_waiting_counts);
+}
+
+/**
+ * cpuidle_coupled_set_not_ready - mark a cpu as not ready
+ * @coupled: the struct coupled that contains the current cpu
+ *
+ * Decrements the ready counter, unless the ready (and thus the waiting) counter
+ * is equal to the number of online cpus.  Prevents a race where one cpu
+ * decrements the waiting counter and then re-increments it just before another
+ * cpu has decremented its ready counter, leading to the ready counter going
+ * down from the number of online cpus without going through the coupled idle
+ * state.
+ *
+ * Returns 0 if the counter was decremented successfully, -EINVAL if the ready
+ * counter was equal to the number of online cpus.
+ */
+static
+inline int cpuidle_coupled_set_not_ready(struct cpuidle_coupled *coupled)
+{
+	int all;
+	int ret;
+
+	all = coupled->online_count | (coupled->online_count << WAITING_BITS);
+	ret = atomic_add_unless(&coupled->ready_waiting_counts,
+		-MAX_WAITING_CPUS, all);
+
+	return ret ? 0 : -EINVAL;
+}
+
+/**
+ * cpuidle_coupled_no_cpus_ready - check if no cpus in a coupled set are ready
+ * @coupled: the struct coupled that contains the current cpu
+ *
+ * Returns true if all of the cpus in a coupled set are out of the ready loop.
+ */
+static inline int cpuidle_coupled_no_cpus_ready(struct cpuidle_coupled *coupled)
+{
+	int r = atomic_read(&coupled->ready_waiting_counts) >> WAITING_BITS;
+	return r == 0;
+}
+
+/**
+ * cpuidle_coupled_cpus_ready - check if all cpus in a coupled set are ready
+ * @coupled: the struct coupled that contains the current cpu
+ *
+ * Returns true if all cpus coupled to this target state are in the ready loop
+ */
+static inline bool cpuidle_coupled_cpus_ready(struct cpuidle_coupled *coupled)
+{
+	int r = atomic_read(&coupled->ready_waiting_counts) >> WAITING_BITS;
+	return r == coupled->online_count;
+}
+
+/**
+ * cpuidle_coupled_cpus_waiting - check if all cpus in a coupled set are waiting
+ * @coupled: the struct coupled that contains the current cpu
+ *
+ * Returns true if all cpus coupled to this target state are in the wait loop
+ */
+static inline bool cpuidle_coupled_cpus_waiting(struct cpuidle_coupled *coupled)
+{
+	int w = atomic_read(&coupled->ready_waiting_counts) & WAITING_MASK;
+	return w == coupled->online_count;
+}
+
+/**
+ * cpuidle_coupled_no_cpus_waiting - check if no cpus in coupled set are waiting
+ * @coupled: the struct coupled that contains the current cpu
+ *
+ * Returns true if all of the cpus in a coupled set are out of the waiting loop.
+ */
+static inline int cpuidle_coupled_no_cpus_waiting(struct cpuidle_coupled *coupled)
+{
+	int w = atomic_read(&coupled->ready_waiting_counts) & WAITING_MASK;
+	return w == 0;
+}
+
+/**
+ * cpuidle_coupled_get_state - determine the deepest idle state
+ * @dev: struct cpuidle_device for this cpu
+ * @coupled: the struct coupled that contains the current cpu
+ *
+ * Returns the deepest idle state that all coupled cpus can enter
+ */
+static inline int cpuidle_coupled_get_state(struct cpuidle_device *dev,
+		struct cpuidle_coupled *coupled)
+{
+	int i;
+	int state = INT_MAX;
+
+	/*
+	 * Read barrier ensures that read of requested_state is ordered after
+	 * reads of ready_count.  Matches the write barriers
+	 * cpuidle_set_state_waiting.
+	 */
+	smp_rmb();
+
+	for_each_cpu_mask(i, coupled->coupled_cpus)
+		if (cpu_online(i) && coupled->requested_state[i] < state)
+			state = coupled->requested_state[i];
+
+	return state;
+}
+
+static void cpuidle_coupled_handle_poke(void *info)
+{
+	int cpu = (unsigned long)info;
+	cpumask_set_cpu(cpu, &cpuidle_coupled_poked);
+	cpumask_clear_cpu(cpu, &cpuidle_coupled_poke_pending);
+}
+
+/**
+ * cpuidle_coupled_poke - wake up a cpu that may be waiting
+ * @cpu: target cpu
+ *
+ * Ensures that the target cpu exits it's waiting idle state (if it is in it)
+ * and will see updates to waiting_count before it re-enters it's waiting idle
+ * state.
+ *
+ * If cpuidle_coupled_poked_mask is already set for the target cpu, that cpu
+ * either has or will soon have a pending IPI that will wake it out of idle,
+ * or it is currently processing the IPI and is not in idle.
+ */
+static void cpuidle_coupled_poke(int cpu)
+{
+	struct call_single_data *csd = &per_cpu(cpuidle_coupled_poke_cb, cpu);
+
+	if (!cpumask_test_and_set_cpu(cpu, &cpuidle_coupled_poke_pending))
+		smp_call_function_single_async(cpu, csd);
+}
+
+/**
+ * cpuidle_coupled_poke_others - wake up all other cpus that may be waiting
+ * @dev: struct cpuidle_device for this cpu
+ * @coupled: the struct coupled that contains the current cpu
+ *
+ * Calls cpuidle_coupled_poke on all other online cpus.
+ */
+static void cpuidle_coupled_poke_others(int this_cpu,
+		struct cpuidle_coupled *coupled)
+{
+	int cpu;
+
+	for_each_cpu_mask(cpu, coupled->coupled_cpus)
+		if (cpu != this_cpu && cpu_online(cpu))
+			cpuidle_coupled_poke(cpu);
+}
+
+/**
+ * cpuidle_coupled_set_waiting - mark this cpu as in the wait loop
+ * @dev: struct cpuidle_device for this cpu
+ * @coupled: the struct coupled that contains the current cpu
+ * @next_state: the index in drv->states of the requested state for this cpu
+ *
+ * Updates the requested idle state for the specified cpuidle device.
+ * Returns the number of waiting cpus.
+ */
+static int cpuidle_coupled_set_waiting(int cpu,
+		struct cpuidle_coupled *coupled, int next_state)
+{
+	coupled->requested_state[cpu] = next_state;
+
+	/*
+	 * The atomic_inc_return provides a write barrier to order the write
+	 * to requested_state with the later write that increments ready_count.
+	 */
+	return atomic_inc_return(&coupled->ready_waiting_counts) & WAITING_MASK;
+}
+
+/**
+ * cpuidle_coupled_set_not_waiting - mark this cpu as leaving the wait loop
+ * @dev: struct cpuidle_device for this cpu
+ * @coupled: the struct coupled that contains the current cpu
+ *
+ * Removes the requested idle state for the specified cpuidle device.
+ */
+static void cpuidle_coupled_set_not_waiting(int cpu,
+		struct cpuidle_coupled *coupled)
+{
+	/*
+	 * Decrementing waiting count can race with incrementing it in
+	 * cpuidle_coupled_set_waiting, but that's OK.  Worst case, some
+	 * cpus will increment ready_count and then spin until they
+	 * notice that this cpu has cleared it's requested_state.
+	 */
+	atomic_dec(&coupled->ready_waiting_counts);
+
+	coupled->requested_state[cpu] = CPUIDLE_COUPLED_NOT_IDLE;
+}
+
+/**
+ * cpuidle_coupled_set_done - mark this cpu as leaving the ready loop
+ * @cpu: the current cpu
+ * @coupled: the struct coupled that contains the current cpu
+ *
+ * Marks this cpu as no longer in the ready and waiting loops.  Decrements
+ * the waiting count first to prevent another cpu looping back in and seeing
+ * this cpu as waiting just before it exits idle.
+ */
+static void cpuidle_coupled_set_done(int cpu, struct cpuidle_coupled *coupled)
+{
+	cpuidle_coupled_set_not_waiting(cpu, coupled);
+	atomic_sub(MAX_WAITING_CPUS, &coupled->ready_waiting_counts);
+}
+
+/**
+ * cpuidle_coupled_clear_pokes - spin until the poke interrupt is processed
+ * @cpu - this cpu
+ *
+ * Turns on interrupts and spins until any outstanding poke interrupts have
+ * been processed and the poke bit has been cleared.
+ *
+ * Other interrupts may also be processed while interrupts are enabled, so
+ * need_resched() must be tested after this function returns to make sure
+ * the interrupt didn't schedule work that should take the cpu out of idle.
+ *
+ * Returns 0 if no poke was pending, 1 if a poke was cleared.
+ */
+static int cpuidle_coupled_clear_pokes(int cpu)
+{
+	if (!cpumask_test_cpu(cpu, &cpuidle_coupled_poke_pending))
+		return 0;
+
+	local_irq_enable();
+	while (cpumask_test_cpu(cpu, &cpuidle_coupled_poke_pending))
+		cpu_relax();
+	local_irq_disable();
+
+	return 1;
+}
+
+static bool cpuidle_coupled_any_pokes_pending(struct cpuidle_coupled *coupled)
+{
+	cpumask_t cpus;
+	int ret;
+
+	cpumask_and(&cpus, cpu_online_mask, &coupled->coupled_cpus);
+	ret = cpumask_and(&cpus, &cpuidle_coupled_poke_pending, &cpus);
+
+	return ret;
+}
+
+/**
+ * cpuidle_enter_state_coupled - attempt to enter a state with coupled cpus
+ * @dev: struct cpuidle_device for the current cpu
+ * @drv: struct cpuidle_driver for the platform
+ * @next_state: index of the requested state in drv->states
+ *
+ * Coordinate with coupled cpus to enter the target state.  This is a two
+ * stage process.  In the first stage, the cpus are operating independently,
+ * and may call into cpuidle_enter_state_coupled at completely different times.
+ * To save as much power as possible, the first cpus to call this function will
+ * go to an intermediate state (the cpuidle_device's safe state), and wait for
+ * all the other cpus to call this function.  Once all coupled cpus are idle,
+ * the second stage will start.  Each coupled cpu will spin until all cpus have
+ * guaranteed that they will call the target_state.
+ *
+ * This function must be called with interrupts disabled.  It may enable
+ * interrupts while preparing for idle, and it will always return with
+ * interrupts enabled.
+ */
+int cpuidle_enter_state_coupled(struct cpuidle_device *dev,
+		struct cpuidle_driver *drv, int next_state)
+{
+	int entered_state = -1;
+	struct cpuidle_coupled *coupled = dev->coupled;
+	int w;
+
+	if (!coupled)
+		return -EINVAL;
+
+	while (coupled->prevent) {
+		cpuidle_coupled_clear_pokes(dev->cpu);
+		if (need_resched()) {
+			local_irq_enable();
+			return entered_state;
+		}
+		entered_state = cpuidle_enter_state(dev, drv,
+			dev->safe_state_index);
+		local_irq_disable();
+	}
+
+	/* Read barrier ensures online_count is read after prevent is cleared */
+	smp_rmb();
+
+reset:
+	cpumask_clear_cpu(dev->cpu, &cpuidle_coupled_poked);
+
+	w = cpuidle_coupled_set_waiting(dev->cpu, coupled, next_state);
+	/*
+	 * If this is the last cpu to enter the waiting state, poke
+	 * all the other cpus out of their waiting state so they can
+	 * enter a deeper state.  This can race with one of the cpus
+	 * exiting the waiting state due to an interrupt and
+	 * decrementing waiting_count, see comment below.
+	 */
+	if (w == coupled->online_count) {
+		cpumask_set_cpu(dev->cpu, &cpuidle_coupled_poked);
+		cpuidle_coupled_poke_others(dev->cpu, coupled);
+	}
+
+retry:
+	/*
+	 * Wait for all coupled cpus to be idle, using the deepest state
+	 * allowed for a single cpu.  If this was not the poking cpu, wait
+	 * for at least one poke before leaving to avoid a race where
+	 * two cpus could arrive at the waiting loop at the same time,
+	 * but the first of the two to arrive could skip the loop without
+	 * processing the pokes from the last to arrive.
+	 */
+	while (!cpuidle_coupled_cpus_waiting(coupled) ||
+			!cpumask_test_cpu(dev->cpu, &cpuidle_coupled_poked)) {
+		if (cpuidle_coupled_clear_pokes(dev->cpu))
+			continue;
+
+		if (need_resched()) {
+			cpuidle_coupled_set_not_waiting(dev->cpu, coupled);
+			goto out;
+		}
+
+		if (coupled->prevent) {
+			cpuidle_coupled_set_not_waiting(dev->cpu, coupled);
+			goto out;
+		}
+
+		entered_state = cpuidle_enter_state(dev, drv,
+			dev->safe_state_index);
+		local_irq_disable();
+	}
+
+	cpuidle_coupled_clear_pokes(dev->cpu);
+	if (need_resched()) {
+		cpuidle_coupled_set_not_waiting(dev->cpu, coupled);
+		goto out;
+	}
+
+	/*
+	 * Make sure final poke status for this cpu is visible before setting
+	 * cpu as ready.
+	 */
+	smp_wmb();
+
+	/*
+	 * All coupled cpus are probably idle.  There is a small chance that
+	 * one of the other cpus just became active.  Increment the ready count,
+	 * and spin until all coupled cpus have incremented the counter. Once a
+	 * cpu has incremented the ready counter, it cannot abort idle and must
+	 * spin until either all cpus have incremented the ready counter, or
+	 * another cpu leaves idle and decrements the waiting counter.
+	 */
+
+	cpuidle_coupled_set_ready(coupled);
+	while (!cpuidle_coupled_cpus_ready(coupled)) {
+		/* Check if any other cpus bailed out of idle. */
+		if (!cpuidle_coupled_cpus_waiting(coupled))
+			if (!cpuidle_coupled_set_not_ready(coupled))
+				goto retry;
+
+		cpu_relax();
+	}
+
+	/*
+	 * Make sure read of all cpus ready is done before reading pending pokes
+	 */
+	smp_rmb();
+
+	/*
+	 * There is a small chance that a cpu left and reentered idle after this
+	 * cpu saw that all cpus were waiting.  The cpu that reentered idle will
+	 * have sent this cpu a poke, which will still be pending after the
+	 * ready loop.  The pending interrupt may be lost by the interrupt
+	 * controller when entering the deep idle state.  It's not possible to
+	 * clear a pending interrupt without turning interrupts on and handling
+	 * it, and it's too late to turn on interrupts here, so reset the
+	 * coupled idle state of all cpus and retry.
+	 */
+	if (cpuidle_coupled_any_pokes_pending(coupled)) {
+		cpuidle_coupled_set_done(dev->cpu, coupled);
+		/* Wait for all cpus to see the pending pokes */
+		cpuidle_coupled_parallel_barrier(dev, &coupled->abort_barrier);
+		goto reset;
+	}
+
+	/* all cpus have acked the coupled state */
+	next_state = cpuidle_coupled_get_state(dev, coupled);
+
+	entered_state = cpuidle_enter_state(dev, drv, next_state);
+
+	cpuidle_coupled_set_done(dev->cpu, coupled);
+
+out:
+	/*
+	 * Normal cpuidle states are expected to return with irqs enabled.
+	 * That leads to an inefficiency where a cpu receiving an interrupt
+	 * that brings it out of idle will process that interrupt before
+	 * exiting the idle enter function and decrementing ready_count.  All
+	 * other cpus will need to spin waiting for the cpu that is processing
+	 * the interrupt.  If the driver returns with interrupts disabled,
+	 * all other cpus will loop back into the safe idle state instead of
+	 * spinning, saving power.
+	 *
+	 * Calling local_irq_enable here allows coupled states to return with
+	 * interrupts disabled, but won't cause problems for drivers that
+	 * exit with interrupts enabled.
+	 */
+	local_irq_enable();
+
+	/*
+	 * Wait until all coupled cpus have exited idle.  There is no risk that
+	 * a cpu exits and re-enters the ready state because this cpu has
+	 * already decremented its waiting_count.
+	 */
+	while (!cpuidle_coupled_no_cpus_ready(coupled))
+		cpu_relax();
+
+	return entered_state;
+}
+
+static void cpuidle_coupled_update_online_cpus(struct cpuidle_coupled *coupled)
+{
+	cpumask_t cpus;
+	cpumask_and(&cpus, cpu_online_mask, &coupled->coupled_cpus);
+	coupled->online_count = cpumask_weight(&cpus);
+}
+
+/**
+ * cpuidle_coupled_register_device - register a coupled cpuidle device
+ * @dev: struct cpuidle_device for the current cpu
+ *
+ * Called from cpuidle_register_device to handle coupled idle init.  Finds the
+ * cpuidle_coupled struct for this set of coupled cpus, or creates one if none
+ * exists yet.
+ */
+int cpuidle_coupled_register_device(struct cpuidle_device *dev)
+{
+	int cpu;
+	struct cpuidle_device *other_dev;
+	struct call_single_data *csd;
+	struct cpuidle_coupled *coupled;
+
+	if (cpumask_empty(&dev->coupled_cpus))
+		return 0;
+
+	for_each_cpu_mask(cpu, dev->coupled_cpus) {
+		other_dev = per_cpu(cpuidle_devices, cpu);
+		if (other_dev && other_dev->coupled) {
+			coupled = other_dev->coupled;
+			goto have_coupled;
+		}
+	}
+
+	/* No existing coupled info found, create a new one */
+	coupled = kzalloc(sizeof(struct cpuidle_coupled), GFP_KERNEL);
+	if (!coupled)
+		return -ENOMEM;
+
+	coupled->coupled_cpus = dev->coupled_cpus;
+
+have_coupled:
+	dev->coupled = coupled;
+	if (WARN_ON(!cpumask_equal(&dev->coupled_cpus, &coupled->coupled_cpus)))
+		coupled->prevent++;
+
+	cpuidle_coupled_update_online_cpus(coupled);
+
+	coupled->refcnt++;
+
+	csd = &per_cpu(cpuidle_coupled_poke_cb, dev->cpu);
+	csd->func = cpuidle_coupled_handle_poke;
+	csd->info = (void *)(unsigned long)dev->cpu;
+
+	return 0;
+}
+
+/**
+ * cpuidle_coupled_unregister_device - unregister a coupled cpuidle device
+ * @dev: struct cpuidle_device for the current cpu
+ *
+ * Called from cpuidle_unregister_device to tear down coupled idle.  Removes the
+ * cpu from the coupled idle set, and frees the cpuidle_coupled_info struct if
+ * this was the last cpu in the set.
+ */
+void cpuidle_coupled_unregister_device(struct cpuidle_device *dev)
+{
+	struct cpuidle_coupled *coupled = dev->coupled;
+
+	if (cpumask_empty(&dev->coupled_cpus))
+		return;
+
+	if (--coupled->refcnt)
+		kfree(coupled);
+	dev->coupled = NULL;
+}
+
+/**
+ * cpuidle_coupled_prevent_idle - prevent cpus from entering a coupled state
+ * @coupled: the struct coupled that contains the cpu that is changing state
+ *
+ * Disables coupled cpuidle on a coupled set of cpus.  Used to ensure that
+ * cpu_online_mask doesn't change while cpus are coordinating coupled idle.
+ */
+static void cpuidle_coupled_prevent_idle(struct cpuidle_coupled *coupled)
+{
+	int cpu = get_cpu();
+
+	/* Force all cpus out of the waiting loop. */
+	coupled->prevent++;
+	cpuidle_coupled_poke_others(cpu, coupled);
+	put_cpu();
+	while (!cpuidle_coupled_no_cpus_waiting(coupled))
+		cpu_relax();
+}
+
+/**
+ * cpuidle_coupled_allow_idle - allows cpus to enter a coupled state
+ * @coupled: the struct coupled that contains the cpu that is changing state
+ *
+ * Enables coupled cpuidle on a coupled set of cpus.  Used to ensure that
+ * cpu_online_mask doesn't change while cpus are coordinating coupled idle.
+ */
+static void cpuidle_coupled_allow_idle(struct cpuidle_coupled *coupled)
+{
+	int cpu = get_cpu();
+
+	/*
+	 * Write barrier ensures readers see the new online_count when they
+	 * see prevent == 0.
+	 */
+	smp_wmb();
+	coupled->prevent--;
+	/* Force cpus out of the prevent loop. */
+	cpuidle_coupled_poke_others(cpu, coupled);
+	put_cpu();
+}
+
+/**
+ * cpuidle_coupled_cpu_notify - notifier called during hotplug transitions
+ * @nb: notifier block
+ * @action: hotplug transition
+ * @hcpu: target cpu number
+ *
+ * Called when a cpu is brought on or offline using hotplug.  Updates the
+ * coupled cpu set appropriately
+ */
+static int cpuidle_coupled_cpu_notify(struct notifier_block *nb,
+		unsigned long action, void *hcpu)
+{
+	int cpu = (unsigned long)hcpu;
+	struct cpuidle_device *dev;
+
+	switch (action & ~CPU_TASKS_FROZEN) {
+	case CPU_UP_PREPARE:
+	case CPU_DOWN_PREPARE:
+	case CPU_ONLINE:
+	case CPU_DEAD:
+	case CPU_UP_CANCELED:
+	case CPU_DOWN_FAILED:
+		break;
+	default:
+		return NOTIFY_OK;
+	}
+
+	mutex_lock(&cpuidle_lock);
+
+	dev = per_cpu(cpuidle_devices, cpu);
+	if (!dev || !dev->coupled)
+		goto out;
+
+	switch (action & ~CPU_TASKS_FROZEN) {
+	case CPU_UP_PREPARE:
+	case CPU_DOWN_PREPARE:
+		cpuidle_coupled_prevent_idle(dev->coupled);
+		break;
+	case CPU_ONLINE:
+	case CPU_DEAD:
+		cpuidle_coupled_update_online_cpus(dev->coupled);
+		/* Fall through */
+	case CPU_UP_CANCELED:
+	case CPU_DOWN_FAILED:
+		cpuidle_coupled_allow_idle(dev->coupled);
+		break;
+	}
+
+out:
+	mutex_unlock(&cpuidle_lock);
+	return NOTIFY_OK;
+}
+
+static struct notifier_block cpuidle_coupled_cpu_notifier = {
+	.notifier_call = cpuidle_coupled_cpu_notify,
+};
+
+static int __init cpuidle_coupled_init(void)
+{
+	return register_cpu_notifier(&cpuidle_coupled_cpu_notifier);
+}
+core_initcall(cpuidle_coupled_init);

drivers/cpuidle/cpuidle-arm64.c

@@ -0,0 +1,133 @@
+/*
+ * ARM64 generic CPU idle driver.
+ *
+ * Copyright (C) 2014 ARM Ltd.
+ * Author: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#define pr_fmt(fmt) "CPUidle arm64: " fmt
+
+#include <linux/cpuidle.h>
+#include <linux/cpumask.h>
+#include <linux/cpu_pm.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+
+#include <asm/cpuidle.h>
+#include <asm/suspend.h>
+
+#include "dt_idle_states.h"
+
+/*
+ * arm64_enter_idle_state - Programs CPU to enter the specified state
+ *
+ * dev: cpuidle device
+ * drv: cpuidle driver
+ * idx: state index
+ *
+ * Called from the CPUidle framework to program the device to the
+ * specified target state selected by the governor.
+ */
+static int arm64_enter_idle_state(struct cpuidle_device *dev,
+				  struct cpuidle_driver *drv, int idx)
+{
+	int ret;
+
+	if (!idx) {
+		cpu_do_idle();
+		return idx;
+	}
+
+	ret = cpu_pm_enter();
+	if (!ret) {
+		/*
+		 * Pass idle state index to cpu_suspend which in turn will
+		 * call the CPU ops suspend protocol with idle index as a
+		 * parameter.
+		 */
+		ret = cpu_suspend(idx);
+
+		cpu_pm_exit();
+	}
+
+	return ret ? -1 : idx;
+}
+
+static struct cpuidle_driver arm64_idle_driver = {
+	.name = "arm64_idle",
+	.owner = THIS_MODULE,
+	/*
+	 * State at index 0 is standby wfi and considered standard
+	 * on all ARM platforms. If in some platforms simple wfi
+	 * can't be used as "state 0", DT bindings must be implemented
+	 * to work around this issue and allow installing a special
+	 * handler for idle state index 0.
+	 */
+	.states[0] = {
+		.enter                  = arm64_enter_idle_state,
+		.exit_latency           = 1,
+		.target_residency       = 1,
+		.power_usage		= UINT_MAX,
+		.flags                  = CPUIDLE_FLAG_TIME_VALID,
+		.name                   = "WFI",
+		.desc                   = "ARM64 WFI",
+	}
+};
+
+static const struct of_device_id arm64_idle_state_match[] __initconst = {
+	{ .compatible = "arm,idle-state",
+	  .data = arm64_enter_idle_state },
+	{ },
+};
+
+/*
+ * arm64_idle_init
+ *
+ * Registers the arm64 specific cpuidle driver with the cpuidle
+ * framework. It relies on core code to parse the idle states
+ * and initialize them using driver data structures accordingly.
+ */
+static int __init arm64_idle_init(void)
+{
+	int cpu, ret;
+	struct cpuidle_driver *drv = &arm64_idle_driver;
+
+	/*
+	 * Initialize idle states data, starting at index 1.
+	 * This driver is DT only, if no DT idle states are detected (ret == 0)
+	 * let the driver initialization fail accordingly since there is no
+	 * reason to initialize the idle driver if only wfi is supported.
+	 */
+	ret = dt_init_idle_driver(drv, arm64_idle_state_match, 1);
+	if (ret <= 0) {
+		if (ret)
+			pr_err("failed to initialize idle states\n");
+		return ret ? : -ENODEV;
+	}
+
+	/*
+	 * Call arch CPU operations in order to initialize
+	 * idle states suspend back-end specific data
+	 */
+	for_each_possible_cpu(cpu) {
+		ret = cpu_init_idle(cpu);
+		if (ret) {
+			pr_err("CPU %d failed to init idle CPU ops\n", cpu);
+			return ret;
+		}
+	}
+
+	ret = cpuidle_register(drv, NULL);
+	if (ret) {
+		pr_err("failed to register cpuidle driver\n");
+		return ret;
+	}
+
+	return 0;
+}
+device_initcall(arm64_idle_init);

drivers/cpuidle/cpuidle-at91.c

@@ -0,0 +1,69 @@
+/*
+ * based on arch/arm/mach-kirkwood/cpuidle.c
+ *
+ * CPU idle support for AT91 SoC
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2.  This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ *
+ * The cpu idle uses wait-for-interrupt and RAM self refresh in order
+ * to implement two idle states -
+ * #1 wait-for-interrupt
+ * #2 wait-for-interrupt and RAM self refresh
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/platform_device.h>
+#include <linux/cpuidle.h>
+#include <linux/io.h>
+#include <linux/export.h>
+#include <asm/proc-fns.h>
+#include <asm/cpuidle.h>
+
+#define AT91_MAX_STATES	2
+
+static void (*at91_standby)(void);
+
+/* Actual code that puts the SoC in different idle states */
+static int at91_enter_idle(struct cpuidle_device *dev,
+			struct cpuidle_driver *drv,
+			       int index)
+{
+	at91_standby();
+	return index;
+}
+
+static struct cpuidle_driver at91_idle_driver = {
+	.name			= "at91_idle",
+	.owner			= THIS_MODULE,
+	.states[0]		= ARM_CPUIDLE_WFI_STATE,
+	.states[1]		= {
+		.enter			= at91_enter_idle,
+		.exit_latency		= 10,
+		.target_residency	= 10000,
+		.flags			= CPUIDLE_FLAG_TIME_VALID,
+		.name			= "RAM_SR",
+		.desc			= "WFI and DDR Self Refresh",
+	},
+	.state_count = AT91_MAX_STATES,
+};
+
+/* Initialize CPU idle by registering the idle states */
+static int at91_cpuidle_probe(struct platform_device *dev)
+{
+	at91_standby = (void *)(dev->dev.platform_data);
+	
+	return cpuidle_register(&at91_idle_driver, NULL);
+}
+
+static struct platform_driver at91_cpuidle_driver = {
+	.driver = {
+		.name = "cpuidle-at91",
+		.owner = THIS_MODULE,
+	},
+	.probe = at91_cpuidle_probe,
+};
+
+module_platform_driver(at91_cpuidle_driver);

drivers/cpuidle/cpuidle-big_little.c

@@ -0,0 +1,232 @@
+/*
+ * Copyright (c) 2013 ARM/Linaro
+ *
+ * Authors: Daniel Lezcano <daniel.lezcano@linaro.org>
+ *          Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
+ *          Nicolas Pitre <nicolas.pitre@linaro.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * Maintainer: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
+ * Maintainer: Daniel Lezcano <daniel.lezcano@linaro.org>
+ */
+#include <linux/cpuidle.h>
+#include <linux/cpu_pm.h>
+#include <linux/slab.h>
+#include <linux/of.h>
+
+#include <asm/cpu.h>
+#include <asm/cputype.h>
+#include <asm/cpuidle.h>
+#include <asm/mcpm.h>
+#include <asm/smp_plat.h>
+#include <asm/suspend.h>
+
+#include "dt_idle_states.h"
+
+static int bl_enter_powerdown(struct cpuidle_device *dev,
+			      struct cpuidle_driver *drv, int idx);
+
+/*
+ * NB: Owing to current menu governor behaviour big and LITTLE
+ * index 1 states have to define exit_latency and target_residency for
+ * cluster state since, when all CPUs in a cluster hit it, the cluster
+ * can be shutdown. This means that when a single CPU enters this state
+ * the exit_latency and target_residency values are somewhat overkill.
+ * There is no notion of cluster states in the menu governor, so CPUs
+ * have to define CPU states where possibly the cluster will be shutdown
+ * depending on the state of other CPUs. idle states entry and exit happen
+ * at random times; however the cluster state provides target_residency
+ * values as if all CPUs in a cluster enter the state at once; this is
+ * somewhat optimistic and behaviour should be fixed either in the governor
+ * or in the MCPM back-ends.
+ * To make this driver 100% generic the number of states and the exit_latency
+ * target_residency values must be obtained from device tree bindings.
+ *
+ * exit_latency: refers to the TC2 vexpress test chip and depends on the
+ * current cluster operating point. It is the time it takes to get the CPU
+ * up and running when the CPU is powered up on cluster wake-up from shutdown.
+ * Current values for big and LITTLE clusters are provided for clusters
+ * running at default operating points.
+ *
+ * target_residency: it is the minimum amount of time the cluster has
+ * to be down to break even in terms of power consumption. cluster
+ * shutdown has inherent dynamic power costs (L2 writebacks to DRAM
+ * being the main factor) that depend on the current operating points.
+ * The current values for both clusters are provided for a CPU whose half
+ * of L2 lines are dirty and require cleaning to DRAM, and takes into
+ * account leakage static power values related to the vexpress TC2 testchip.
+ */
+static struct cpuidle_driver bl_idle_little_driver = {
+	.name = "little_idle",
+	.owner = THIS_MODULE,
+	.states[0] = ARM_CPUIDLE_WFI_STATE,
+	.states[1] = {
+		.enter			= bl_enter_powerdown,
+		.exit_latency		= 700,
+		.target_residency	= 2500,
+		.flags			= CPUIDLE_FLAG_TIME_VALID |
+					  CPUIDLE_FLAG_TIMER_STOP,
+		.name			= "C1",
+		.desc			= "ARM little-cluster power down",
+	},
+	.state_count = 2,
+};
+
+static const struct of_device_id bl_idle_state_match[] __initconst = {
+	{ .compatible = "arm,idle-state",
+	  .data = bl_enter_powerdown },
+	{ },
+};
+
+static struct cpuidle_driver bl_idle_big_driver = {
+	.name = "big_idle",
+	.owner = THIS_MODULE,
+	.states[0] = ARM_CPUIDLE_WFI_STATE,
+	.states[1] = {
+		.enter			= bl_enter_powerdown,
+		.exit_latency		= 500,
+		.target_residency	= 2000,
+		.flags			= CPUIDLE_FLAG_TIME_VALID |
+					  CPUIDLE_FLAG_TIMER_STOP,
+		.name			= "C1",
+		.desc			= "ARM big-cluster power down",
+	},
+	.state_count = 2,
+};
+
+/*
+ * notrace prevents trace shims from getting inserted where they
+ * should not. Global jumps and ldrex/strex must not be inserted
+ * in power down sequences where caches and MMU may be turned off.
+ */
+static int notrace bl_powerdown_finisher(unsigned long arg)
+{
+	/* MCPM works with HW CPU identifiers */
+	unsigned int mpidr = read_cpuid_mpidr();
+	unsigned int cluster = MPIDR_AFFINITY_LEVEL(mpidr, 1);
+	unsigned int cpu = MPIDR_AFFINITY_LEVEL(mpidr, 0);
+
+	mcpm_set_entry_vector(cpu, cluster, cpu_resume);
+
+	/*
+	 * Residency value passed to mcpm_cpu_suspend back-end
+	 * has to be given clear semantics. Set to 0 as a
+	 * temporary value.
+	 */
+	mcpm_cpu_suspend(0);
+
+	/* return value != 0 means failure */
+	return 1;
+}
+
+/**
+ * bl_enter_powerdown - Programs CPU to enter the specified state
+ * @dev: cpuidle device
+ * @drv: The target state to be programmed
+ * @idx: state index
+ *
+ * Called from the CPUidle framework to program the device to the
+ * specified target state selected by the governor.
+ */
+static int bl_enter_powerdown(struct cpuidle_device *dev,
+				struct cpuidle_driver *drv, int idx)
+{
+	cpu_pm_enter();
+
+	cpu_suspend(0, bl_powerdown_finisher);
+
+	/* signals the MCPM core that CPU is out of low power state */
+	mcpm_cpu_powered_up();
+
+	cpu_pm_exit();
+
+	return idx;
+}
+
+static int __init bl_idle_driver_init(struct cpuidle_driver *drv, int part_id)
+{
+	struct cpumask *cpumask;
+	int cpu;
+
+	cpumask = kzalloc(cpumask_size(), GFP_KERNEL);
+	if (!cpumask)
+		return -ENOMEM;
+
+	for_each_possible_cpu(cpu)
+		if (smp_cpuid_part(cpu) == part_id)
+			cpumask_set_cpu(cpu, cpumask);
+
+	drv->cpumask = cpumask;
+
+	return 0;
+}
+
+static const struct of_device_id compatible_machine_match[] = {
+	{ .compatible = "arm,vexpress,v2p-ca15_a7" },
+	{ .compatible = "samsung,exynos5420" },
+	{ .compatible = "samsung,exynos5800" },
+	{},
+};
+
+static int __init bl_idle_init(void)
+{
+	int ret;
+	struct device_node *root = of_find_node_by_path("/");
+
+	if (!root)
+		return -ENODEV;
+
+	/*
+	 * Initialize the driver just for a compliant set of machines
+	 */
+	if (!of_match_node(compatible_machine_match, root))
+		return -ENODEV;
+	/*
+	 * For now the differentiation between little and big cores
+	 * is based on the part number. A7 cores are considered little
+	 * cores, A15 are considered big cores. This distinction may
+	 * evolve in the future with a more generic matching approach.
+	 */
+	ret = bl_idle_driver_init(&bl_idle_little_driver,
+				  ARM_CPU_PART_CORTEX_A7);
+	if (ret)
+		return ret;
+
+	ret = bl_idle_driver_init(&bl_idle_big_driver, ARM_CPU_PART_CORTEX_A15);
+	if (ret)
+		goto out_uninit_little;
+
+	/* Start at index 1, index 0 standard WFI */
+	ret = dt_init_idle_driver(&bl_idle_big_driver, bl_idle_state_match, 1);
+	if (ret < 0)
+		goto out_uninit_big;
+
+	/* Start at index 1, index 0 standard WFI */
+	ret = dt_init_idle_driver(&bl_idle_little_driver,
+				  bl_idle_state_match, 1);
+	if (ret < 0)
+		goto out_uninit_big;
+
+	ret = cpuidle_register(&bl_idle_little_driver, NULL);
+	if (ret)
+		goto out_uninit_big;
+
+	ret = cpuidle_register(&bl_idle_big_driver, NULL);
+	if (ret)
+		goto out_unregister_little;
+
+	return 0;
+
+out_unregister_little:
+	cpuidle_unregister(&bl_idle_little_driver);
+out_uninit_big:
+	kfree(bl_idle_big_driver.cpumask);
+out_uninit_little:
+	kfree(bl_idle_little_driver.cpumask);
+
+	return ret;
+}
+device_initcall(bl_idle_init);

drivers/cpuidle/cpuidle-calxeda.c

@@ -0,0 +1,81 @@
+/*
+ * Copyright 2012 Calxeda, Inc.
+ *
+ * Based on arch/arm/plat-mxc/cpuidle.c: #v3.7
+ * Copyright 2012 Freescale Semiconductor, Inc.
+ * Copyright 2012 Linaro Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Maintainer: Rob Herring <rob.herring@calxeda.com>
+ */
+
+#include <linux/cpuidle.h>
+#include <linux/cpu_pm.h>
+#include <linux/init.h>
+#include <linux/mm.h>
+#include <linux/platform_device.h>
+#include <asm/cpuidle.h>
+#include <asm/suspend.h>
+#include <asm/psci.h>
+
+static int calxeda_idle_finish(unsigned long val)
+{
+	const struct psci_power_state ps = {
+		.type = PSCI_POWER_STATE_TYPE_POWER_DOWN,
+	};
+	return psci_ops.cpu_suspend(ps, __pa(cpu_resume));
+}
+
+static int calxeda_pwrdown_idle(struct cpuidle_device *dev,
+				struct cpuidle_driver *drv,
+				int index)
+{
+	cpu_pm_enter();
+	cpu_suspend(0, calxeda_idle_finish);
+	cpu_pm_exit();
+
+	return index;
+}
+
+static struct cpuidle_driver calxeda_idle_driver = {
+	.name = "calxeda_idle",
+	.states = {
+		ARM_CPUIDLE_WFI_STATE,
+		{
+			.name = "PG",
+			.desc = "Power Gate",
+			.flags = CPUIDLE_FLAG_TIME_VALID,
+			.exit_latency = 30,
+			.power_usage = 50,
+			.target_residency = 200,
+			.enter = calxeda_pwrdown_idle,
+		},
+	},
+	.state_count = 2,
+};
+
+static int calxeda_cpuidle_probe(struct platform_device *pdev)
+{
+	return cpuidle_register(&calxeda_idle_driver, NULL);
+}
+
+static struct platform_driver calxeda_cpuidle_plat_driver = {
+        .driver = {
+                .name = "cpuidle-calxeda",
+                .owner = THIS_MODULE,
+        },
+        .probe = calxeda_cpuidle_probe,
+};
+
+module_platform_driver(calxeda_cpuidle_plat_driver);

drivers/cpuidle/cpuidle-clps711x.c

@@ -0,0 +1,64 @@
+/*
+ *  CLPS711X CPU idle driver
+ *
+ *  Copyright (C) 2014 Alexander Shiyan <shc_work@mail.ru>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/cpuidle.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+
+#define CLPS711X_CPUIDLE_NAME	"clps711x-cpuidle"
+
+static void __iomem *clps711x_halt;
+
+static int clps711x_cpuidle_halt(struct cpuidle_device *dev,
+				 struct cpuidle_driver *drv, int index)
+{
+	writel(0xaa, clps711x_halt);
+
+	return index;
+}
+
+static struct cpuidle_driver clps711x_idle_driver = {
+	.name		= CLPS711X_CPUIDLE_NAME,
+	.owner		= THIS_MODULE,
+	.states[0]	= {
+		.name		= "HALT",
+		.desc		= "CLPS711X HALT",
+		.enter		= clps711x_cpuidle_halt,
+		.exit_latency	= 1,
+	},
+	.state_count	= 1,
+};
+
+static int __init clps711x_cpuidle_probe(struct platform_device *pdev)
+{
+	struct resource *res;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	clps711x_halt = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(clps711x_halt))
+		return PTR_ERR(clps711x_halt);
+
+	return cpuidle_register(&clps711x_idle_driver, NULL);
+}
+
+static struct platform_driver clps711x_cpuidle_driver = {
+	.driver	= {
+		.name	= CLPS711X_CPUIDLE_NAME,
+		.owner	= THIS_MODULE,
+	},
+};
+module_platform_driver_probe(clps711x_cpuidle_driver, clps711x_cpuidle_probe);
+
+MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>");
+MODULE_DESCRIPTION("CLPS711X CPU idle driver");
+MODULE_LICENSE("GPL");

drivers/cpuidle/cpuidle-cps.c

@@ -0,0 +1,186 @@
+/*
+ * Copyright (C) 2014 Imagination Technologies
+ * Author: Paul Burton <paul.burton@imgtec.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation;  either version 2 of the  License, or (at your
+ * option) any later version.
+ */
+
+#include <linux/cpu_pm.h>
+#include <linux/cpuidle.h>
+#include <linux/init.h>
+
+#include <asm/idle.h>
+#include <asm/pm-cps.h>
+
+/* Enumeration of the various idle states this driver may enter */
+enum cps_idle_state {
+	STATE_WAIT = 0,		/* MIPS wait instruction, coherent */
+	STATE_NC_WAIT,		/* MIPS wait instruction, non-coherent */
+	STATE_CLOCK_GATED,	/* Core clock gated */
+	STATE_POWER_GATED,	/* Core power gated */
+	STATE_COUNT
+};
+
+static int cps_nc_enter(struct cpuidle_device *dev,
+			struct cpuidle_driver *drv, int index)
+{
+	enum cps_pm_state pm_state;
+	int err;
+
+	/*
+	 * At least one core must remain powered up & clocked in order for the
+	 * system to have any hope of functioning.
+	 *
+	 * TODO: don't treat core 0 specially, just prevent the final core
+	 * TODO: remap interrupt affinity temporarily
+	 */
+	if (!cpu_data[dev->cpu].core && (index > STATE_NC_WAIT))
+		index = STATE_NC_WAIT;
+
+	/* Select the appropriate cps_pm_state */
+	switch (index) {
+	case STATE_NC_WAIT:
+		pm_state = CPS_PM_NC_WAIT;
+		break;
+	case STATE_CLOCK_GATED:
+		pm_state = CPS_PM_CLOCK_GATED;
+		break;
+	case STATE_POWER_GATED:
+		pm_state = CPS_PM_POWER_GATED;
+		break;
+	default:
+		BUG();
+		return -EINVAL;
+	}
+
+	/* Notify listeners the CPU is about to power down */
+	if ((pm_state == CPS_PM_POWER_GATED) && cpu_pm_enter())
+		return -EINTR;
+
+	/* Enter that state */
+	err = cps_pm_enter_state(pm_state);
+
+	/* Notify listeners the CPU is back up */
+	if (pm_state == CPS_PM_POWER_GATED)
+		cpu_pm_exit();
+
+	return err ?: index;
+}
+
+static struct cpuidle_driver cps_driver = {
+	.name			= "cpc_cpuidle",
+	.owner			= THIS_MODULE,
+	.states = {
+		[STATE_WAIT] = MIPS_CPUIDLE_WAIT_STATE,
+		[STATE_NC_WAIT] = {
+			.enter	= cps_nc_enter,
+			.exit_latency		= 200,
+			.target_residency	= 450,
+			.flags	= CPUIDLE_FLAG_TIME_VALID,
+			.name	= "nc-wait",
+			.desc	= "non-coherent MIPS wait",
+		},
+		[STATE_CLOCK_GATED] = {
+			.enter	= cps_nc_enter,
+			.exit_latency		= 300,
+			.target_residency	= 700,
+			.flags	= CPUIDLE_FLAG_TIME_VALID |
+				  CPUIDLE_FLAG_TIMER_STOP,
+			.name	= "clock-gated",
+			.desc	= "core clock gated",
+		},
+		[STATE_POWER_GATED] = {
+			.enter	= cps_nc_enter,
+			.exit_latency		= 600,
+			.target_residency	= 1000,
+			.flags	= CPUIDLE_FLAG_TIME_VALID |
+				  CPUIDLE_FLAG_TIMER_STOP,
+			.name	= "power-gated",
+			.desc	= "core power gated",
+		},
+	},
+	.state_count		= STATE_COUNT,
+	.safe_state_index	= 0,
+};
+
+static void __init cps_cpuidle_unregister(void)
+{
+	int cpu;
+	struct cpuidle_device *device;
+
+	for_each_possible_cpu(cpu) {
+		device = &per_cpu(cpuidle_dev, cpu);
+		cpuidle_unregister_device(device);
+	}
+
+	cpuidle_unregister_driver(&cps_driver);
+}
+
+static int __init cps_cpuidle_init(void)
+{
+	int err, cpu, core, i;
+	struct cpuidle_device *device;
+
+	/* Detect supported states */
+	if (!cps_pm_support_state(CPS_PM_POWER_GATED))
+		cps_driver.state_count = STATE_CLOCK_GATED + 1;
+	if (!cps_pm_support_state(CPS_PM_CLOCK_GATED))
+		cps_driver.state_count = STATE_NC_WAIT + 1;
+	if (!cps_pm_support_state(CPS_PM_NC_WAIT))
+		cps_driver.state_count = STATE_WAIT + 1;
+
+	/* Inform the user if some states are unavailable */
+	if (cps_driver.state_count < STATE_COUNT) {
+		pr_info("cpuidle-cps: limited to ");
+		switch (cps_driver.state_count - 1) {
+		case STATE_WAIT:
+			pr_cont("coherent wait\n");
+			break;
+		case STATE_NC_WAIT:
+			pr_cont("non-coherent wait\n");
+			break;
+		case STATE_CLOCK_GATED:
+			pr_cont("clock gating\n");
+			break;
+		}
+	}
+
+	/*
+	 * Set the coupled flag on the appropriate states if this system
+	 * requires it.
+	 */
+	if (coupled_coherence)
+		for (i = STATE_NC_WAIT; i < cps_driver.state_count; i++)
+			cps_driver.states[i].flags |= CPUIDLE_FLAG_COUPLED;
+
+	err = cpuidle_register_driver(&cps_driver);
+	if (err) {
+		pr_err("Failed to register CPS cpuidle driver\n");
+		return err;
+	}
+
+	for_each_possible_cpu(cpu) {
+		core = cpu_data[cpu].core;
+		device = &per_cpu(cpuidle_dev, cpu);
+		device->cpu = cpu;
+#ifdef CONFIG_MIPS_MT
+		cpumask_copy(&device->coupled_cpus, &cpu_sibling_map[cpu]);
+#endif
+
+		err = cpuidle_register_device(device);
+		if (err) {
+			pr_err("Failed to register CPU%d cpuidle device\n",
+			       cpu);
+			goto err_out;
+		}
+	}
+
+	return 0;
+err_out:
+	cps_cpuidle_unregister();
+	return err;
+}
+device_initcall(cps_cpuidle_init);

drivers/cpuidle/cpuidle-exynos.c

@@ -0,0 +1,82 @@
+/* linux/arch/arm/mach-exynos/cpuidle.c
+ *
+ * Copyright (c) 2011 Samsung Electronics Co., Ltd.
+ *		http://www.samsung.com
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+*/
+
+#include <linux/cpuidle.h>
+#include <linux/cpu_pm.h>
+#include <linux/export.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+
+#include <asm/proc-fns.h>
+#include <asm/suspend.h>
+#include <asm/cpuidle.h>
+
+static void (*exynos_enter_aftr)(void);
+
+static int exynos_enter_lowpower(struct cpuidle_device *dev,
+				struct cpuidle_driver *drv,
+				int index)
+{
+	int new_index = index;
+
+	/* AFTR can only be entered when cores other than CPU0 are offline */
+	if (num_online_cpus() > 1 || dev->cpu != 0)
+		new_index = drv->safe_state_index;
+
+	if (new_index == 0)
+		return arm_cpuidle_simple_enter(dev, drv, new_index);
+
+	exynos_enter_aftr();
+
+	return new_index;
+}
+
+static struct cpuidle_driver exynos_idle_driver = {
+	.name			= "exynos_idle",
+	.owner			= THIS_MODULE,
+	.states = {
+		[0] = ARM_CPUIDLE_WFI_STATE,
+		[1] = {
+			.enter			= exynos_enter_lowpower,
+			.exit_latency		= 300,
+			.target_residency	= 100000,
+			.flags			= CPUIDLE_FLAG_TIME_VALID,
+			.name			= "C1",
+			.desc			= "ARM power down",
+		},
+	},
+	.state_count = 2,
+	.safe_state_index = 0,
+};
+
+static int exynos_cpuidle_probe(struct platform_device *pdev)
+{
+	int ret;
+
+	exynos_enter_aftr = (void *)(pdev->dev.platform_data);
+
+	ret = cpuidle_register(&exynos_idle_driver, NULL);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to register cpuidle driver\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+static struct platform_driver exynos_cpuidle_driver = {
+	.probe	= exynos_cpuidle_probe,
+	.driver = {
+		.name = "exynos_cpuidle",
+		.owner = THIS_MODULE,
+	},
+};
+
+module_platform_driver(exynos_cpuidle_driver);

drivers/cpuidle/cpuidle-exynos64.c

@@ -0,0 +1,414 @@
+/*
+ * Copyright (c) 2014 Samsung Electronics Co., Ltd.
+ *		http://www.samsung.com
+ *
+ * CPUIDLE driver for exynos 64bit
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+*/
+
+#include <linux/cpuidle.h>
+#include <linux/cpu_pm.h>
+#include <linux/slab.h>
+#include <linux/io.h>
+#include <linux/suspend.h>
+#include <linux/cpu.h>
+#include <linux/reboot.h>
+#include <linux/of.h>
+#include <linux/cpuidle_profiler.h>
+#ifdef CONFIG_SEC_PM
+#include <linux/moduleparam.h>
+#endif
+
+#include <asm/suspend.h>
+#include <asm/tlbflush.h>
+#include <asm/psci.h>
+#include <asm/cpuidle.h>
+#include <asm/topology.h>
+
+#include <soc/samsung/exynos-powermode.h>
+
+#include "dt_idle_states.h"
+
+#ifdef CONFIG_SEC_PM
+#define CPUIDLE_ENABLE_MASK (ENABLE_C2 | ENABLE_C3_LPM)
+
+static enum {
+	ENABLE_C2	= BIT(0),
+	ENABLE_C3_LPM	= BIT(1),
+} enable_mask = CPUIDLE_ENABLE_MASK;
+
+DEFINE_SPINLOCK(enable_mask_lock);
+
+static int set_enable_mask(const char *val, const struct kernel_param *kp)
+{
+	int rv = param_set_uint(val, kp);
+	unsigned long flags;
+
+	pr_info("%s: enable_mask=0x%x\n", __func__, enable_mask);
+
+	if (rv)
+		return rv;
+
+	spin_lock_irqsave(&enable_mask_lock, flags);
+
+	if (!(enable_mask & ENABLE_C2)) {
+		unsigned int cpuid = smp_processor_id();
+		int i;
+		for_each_online_cpu(i) {
+			if (i == cpuid)
+				continue;
+			smp_send_reschedule(i);
+		}
+	}
+
+	spin_unlock_irqrestore(&enable_mask_lock, flags);
+
+	return 0;
+}
+
+static struct kernel_param_ops enable_mask_param_ops = {
+	.set = set_enable_mask,
+	.get = param_get_uint,
+};
+
+module_param_cb(enable_mask, &enable_mask_param_ops, &enable_mask, 0644);
+MODULE_PARM_DESC(enable_mask, "bitmask for C states - C2, C3(LPM)");
+#endif /* CONFIG_SEC_PM */
+
+#ifdef CONFIG_SEC_PM_DEBUG
+unsigned int log_en;
+module_param_named(log_en, log_en, uint, 0644);
+#endif /* CONFIG_SEC_PM_DEBUG */
+
+/*
+ * Exynos cpuidle driver supports the below idle states
+ *
+ * IDLE_C1 : WFI(Wait For Interrupt) low-power state
+ * IDLE_C2 : Local CPU power gating
+ * IDLE_LPM : Low Power Mode, specified by platform
+ */
+enum idle_state {
+	IDLE_C1 = 0,
+	IDLE_C2,
+	IDLE_LPM,
+};
+
+/***************************************************************************
+ *                             Helper function                             *
+ ***************************************************************************/
+static void prepare_idle(unsigned int cpuid)
+{
+	cpu_pm_enter();
+}
+
+static void post_idle(unsigned int cpuid)
+{
+	cpu_pm_exit();
+}
+
+static bool nonboot_cpus_working(void)
+{
+	return (num_online_cpus() > 1);
+}
+
+static int find_available_low_state(struct cpuidle_device *dev,
+				struct cpuidle_driver *drv, unsigned int index)
+{
+	while (--index > 0) {
+		struct cpuidle_state *s = &drv->states[index];
+		struct cpuidle_state_usage *su = &dev->states_usage[index];
+
+		if (s->disabled || su->disable)
+			continue;
+		else
+			return index;
+	}
+
+	return IDLE_C1;
+}
+
+/***************************************************************************
+ *                           Cpuidle state handler                         *
+ ***************************************************************************/
+static int exynos_enter_idle(struct cpuidle_device *dev,
+				struct cpuidle_driver *drv, int index)
+{
+	cpuidle_profile_start_no_substate(dev->cpu, index);
+
+	cpu_do_idle();
+
+	cpuidle_profile_finish_no_earlywakeup(dev->cpu);
+
+	return index;
+}
+
+static int exynos_enter_c2(struct cpuidle_device *dev,
+				struct cpuidle_driver *drv, int index)
+{
+	int ret, entry_index;
+
+#ifdef CONFIG_SEC_PM_DEBUG
+	if (unlikely(log_en & ENABLE_C2))
+		pr_info("+++c2\n");
+#endif
+	prepare_idle(dev->cpu);
+
+	entry_index = enter_c2(dev->cpu, index);
+
+	cpuidle_profile_start(dev->cpu, index, entry_index);
+
+	ret = cpu_suspend(entry_index);
+	if (ret)
+		flush_tlb_all();
+
+	cpuidle_profile_finish(dev->cpu, ret);
+
+	wakeup_from_c2(dev->cpu, ret);
+
+	post_idle(dev->cpu);
+
+#ifdef CONFIG_SEC_PM_DEBUG
+	if (unlikely(log_en & ENABLE_C2))
+		pr_info("---c2\n");
+#endif
+	return index;
+}
+
+static int exynos_enter_lpm(struct cpuidle_device *dev,
+				struct cpuidle_driver *drv, int index)
+{
+	int ret, mode;
+
+	mode = determine_lpm();
+
+#ifdef CONFIG_SEC_PM_DEBUG
+	if (unlikely(log_en & ENABLE_C3_LPM))
+		pr_info("+++lpm:%d\n", mode);
+#endif
+	prepare_idle(dev->cpu);
+
+	exynos_prepare_sys_powerdown(mode, false);
+
+	cpuidle_profile_start(dev->cpu, index, mode);
+
+	ret = cpu_suspend(index);
+
+	cpuidle_profile_finish(dev->cpu, ret);
+
+	exynos_wakeup_sys_powerdown(mode, (bool)ret);
+
+	post_idle(dev->cpu);
+
+#ifdef CONFIG_SEC_PM_DEBUG
+	if (unlikely(log_en & ENABLE_C3_LPM))
+		pr_info("---lpm:%d\n", mode);
+#endif
+	return index;
+}
+
+static int exynos_enter_idle_state(struct cpuidle_device *dev,
+				struct cpuidle_driver *drv, int index)
+{
+	int (*func)(struct cpuidle_device *, struct cpuidle_driver *, int);
+
+#ifdef CONFIG_SEC_PM
+	switch (index) {
+	case IDLE_C2:
+		if (unlikely(!(enable_mask & ENABLE_C2)))
+			index = IDLE_C1;
+		break;
+	case IDLE_LPM:
+		if (unlikely(!(enable_mask & ENABLE_C3_LPM))) {
+			if (enable_mask & ENABLE_C2)
+				index = IDLE_C2;
+			else
+				index = IDLE_C1;
+		}
+		break;
+	default:
+		break;
+	}
+#endif
+
+	switch (index) {
+	case IDLE_C1:
+		func = exynos_enter_idle;
+		break;
+	case IDLE_C2:
+		func = exynos_enter_c2;
+		break;
+	case IDLE_LPM:
+		/*
+		 * In exynos, system can enter LPM when only boot core is running.
+		 * In other words, non-boot cores should be shutdown to enter LPM.
+		 */
+		if (nonboot_cpus_working()) {
+			index = find_available_low_state(dev, drv, index);
+			return exynos_enter_idle_state(dev, drv, index);
+		} else {
+			func = exynos_enter_lpm;
+		}
+		break;
+	default:
+		pr_err("%s : Invalid index: %d\n", __func__, index);
+		return -EINVAL;
+	}
+
+	return (*func)(dev, drv, index);
+}
+
+/***************************************************************************
+ *                            Define notifier call                         *
+ ***************************************************************************/
+static int exynos_cpuidle_notifier_event(struct notifier_block *this,
+					  unsigned long event,
+					  void *ptr)
+{
+	switch (event) {
+	case PM_SUSPEND_PREPARE:
+		cpu_idle_poll_ctrl(true);
+		return NOTIFY_OK;
+	case PM_POST_RESTORE:
+	case PM_POST_SUSPEND:
+		cpu_idle_poll_ctrl(false);
+		return NOTIFY_OK;
+	}
+
+	return NOTIFY_DONE;
+}
+
+static struct notifier_block exynos_cpuidle_notifier = {
+	.notifier_call = exynos_cpuidle_notifier_event,
+};
+
+static int exynos_cpuidle_reboot_notifier(struct notifier_block *this,
+				unsigned long event, void *_cmd)
+{
+	switch (event) {
+	case SYSTEM_POWER_OFF:
+	case SYS_RESTART:
+		cpu_idle_poll_ctrl(true);
+		break;
+	}
+
+	return NOTIFY_OK;
+}
+
+static struct notifier_block exynos_cpuidle_reboot_nb = {
+	.notifier_call = exynos_cpuidle_reboot_notifier,
+};
+
+/***************************************************************************
+ *                         Initialize cpuidle driver                       *
+ ***************************************************************************/
+#define exynos_idle_wfi_state(state)					\
+	do {								\
+		state.enter = exynos_enter_idle;			\
+		state.exit_latency = 1;					\
+		state.target_residency = 1;				\
+		state.power_usage = UINT_MAX;				\
+		state.flags = CPUIDLE_FLAG_TIME_VALID;			\
+		strncpy(state.name, "WFI", CPUIDLE_NAME_LEN - 1);	\
+		strncpy(state.desc, "ARM WFI", CPUIDLE_DESC_LEN - 1);	\
+	} while (0)
+
+static struct cpuidle_driver exynos_idle_driver[NR_CPUS];
+
+static const struct of_device_id exynos_idle_state_match[] __initconst = {
+	{ .compatible = "exynos,idle-state",
+	  .data = exynos_enter_idle_state },
+	{ },
+};
+
+static int __init exynos_idle_driver_init(struct cpuidle_driver *drv,
+					   struct cpumask* cpumask)
+{
+	int cpu = cpumask_first(cpumask);
+	int master_cpu = cpumask_first(cpu_possible_mask);
+
+	drv->name = kzalloc(sizeof("exynos_idleX"), GFP_KERNEL);
+	if (!drv->name)
+		return -ENOMEM;
+
+	scnprintf((char *)drv->name, 12, "exynos_idle%d", cpu);
+	drv->owner = THIS_MODULE;
+	drv->cpumask = cpumask;
+	exynos_idle_wfi_state(drv->states[0]);
+
+	/* TODO: no idea about skip_correction yet. */
+	if (topology_physical_package_id(cpu)
+			!= topology_physical_package_id(master_cpu))
+		drv->skip_correction = 1;
+
+	return 0;
+}
+
+
+static int __init exynos_idle_init(void)
+{
+	int ret, cpu, i;
+
+	for_each_possible_cpu(cpu) {
+		ret = exynos_idle_driver_init(&exynos_idle_driver[cpu],
+					      topology_thread_cpumask(cpu));
+
+		if (ret) {
+			pr_err("CPU %d failed to init exynos idle driver : %d",
+					cpu, ret);
+			goto err_exynos_idle_first;
+		}
+		/*
+		 * Initialize idle states data, starting at index 1.
+		 * This driver is DT only, if no DT idle states are detected
+		 * (ret == 0) let the driver initialization fail accordingly
+		 * since there is no reason to initialize the idle driver
+		 * if only wfi is supported.
+		 */
+		ret = dt_init_idle_driver(&exynos_idle_driver[cpu],
+					exynos_idle_state_match, 1);
+		if (ret < 0) {
+			pr_err("CPU %d failed to init DT : %d\n", cpu, ret);
+			goto err_exynos_idle_init;
+		}
+		/*
+		 * Call arch CPU operations in order to initialize
+		 * idle states suspend back-end specific data
+		 */
+		ret = cpu_init_idle(cpu);
+		if (ret) {
+			pr_err("CPU %d failed to init idle CPU ops : %d\n", cpu, ret);
+			goto err_exynos_idle_init;
+		}
+	}
+
+	for_each_possible_cpu(cpu) {
+		ret = cpuidle_register(&exynos_idle_driver[cpu], NULL);
+		if (ret) {
+			pr_err("CPU %d failed to register cpuidle\n", cpu);
+			goto out_cpuidle_unregister;
+		}
+	}
+
+	register_pm_notifier(&exynos_cpuidle_notifier);
+	register_reboot_notifier(&exynos_cpuidle_reboot_nb);
+
+	cpu = cpumask_first(cpu_possible_mask);
+	cpuidle_profile_register(&exynos_idle_driver[cpu]);
+
+	pr_info("Exynos cpuidle driver Initialized\n");
+
+	return 0;
+
+out_cpuidle_unregister:
+	for (i = cpu; i > 0; i--)
+		cpuidle_unregister(&exynos_idle_driver[i-1]);
+err_exynos_idle_init:
+err_exynos_idle_first:
+	for (i = cpu; i > 0; i--)
+		kfree(exynos_idle_driver[i-1].name);
+	return ret;
+}
+device_initcall(exynos_idle_init);

drivers/cpuidle/cpuidle-kirkwood.c

@@ -0,0 +1,90 @@
+/*
+ * CPU idle Marvell Kirkwood SoCs
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2.  This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ *
+ * The cpu idle uses wait-for-interrupt and DDR self refresh in order
+ * to implement two idle states -
+ * #1 wait-for-interrupt
+ * #2 wait-for-interrupt and DDR self refresh
+ *
+ * Maintainer: Jason Cooper <jason@lakedaemon.net>
+ * Maintainer: Andrew Lunn <andrew@lunn.ch>
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/platform_device.h>
+#include <linux/cpuidle.h>
+#include <linux/io.h>
+#include <linux/export.h>
+#include <asm/proc-fns.h>
+#include <asm/cpuidle.h>
+
+#define KIRKWOOD_MAX_STATES	2
+
+static void __iomem *ddr_operation_base;
+
+/* Actual code that puts the SoC in different idle states */
+static int kirkwood_enter_idle(struct cpuidle_device *dev,
+			       struct cpuidle_driver *drv,
+			       int index)
+{
+	writel(0x7, ddr_operation_base);
+	cpu_do_idle();
+
+	return index;
+}
+
+static struct cpuidle_driver kirkwood_idle_driver = {
+	.name			= "kirkwood_idle",
+	.owner			= THIS_MODULE,
+	.states[0]		= ARM_CPUIDLE_WFI_STATE,
+	.states[1]		= {
+		.enter			= kirkwood_enter_idle,
+		.exit_latency		= 10,
+		.target_residency	= 100000,
+		.flags			= CPUIDLE_FLAG_TIME_VALID,
+		.name			= "DDR SR",
+		.desc			= "WFI and DDR Self Refresh",
+	},
+	.state_count = KIRKWOOD_MAX_STATES,
+};
+
+/* Initialize CPU idle by registering the idle states */
+static int kirkwood_cpuidle_probe(struct platform_device *pdev)
+{
+	struct resource *res;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	ddr_operation_base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(ddr_operation_base))
+		return PTR_ERR(ddr_operation_base);
+
+	return cpuidle_register(&kirkwood_idle_driver, NULL);
+}
+
+static int kirkwood_cpuidle_remove(struct platform_device *pdev)
+{
+	cpuidle_unregister(&kirkwood_idle_driver);
+	return 0;
+}
+
+static struct platform_driver kirkwood_cpuidle_driver = {
+	.probe = kirkwood_cpuidle_probe,
+	.remove = kirkwood_cpuidle_remove,
+	.driver = {
+		   .name = "kirkwood_cpuidle",
+		   .owner = THIS_MODULE,
+		   },
+};
+
+module_platform_driver(kirkwood_cpuidle_driver);
+
+MODULE_AUTHOR("Andrew Lunn <andrew@lunn.ch>");
+MODULE_DESCRIPTION("Kirkwood cpu idle driver");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:kirkwood-cpuidle");

drivers/cpuidle/cpuidle-mvebu-v7.c

@@ -0,0 +1,150 @@
+/*
+ * Marvell Armada 370, 38x and XP SoC cpuidle driver
+ *
+ * Copyright (C) 2014 Marvell
+ *
+ * Nadav Haklai <nadavh@marvell.com>
+ * Gregory CLEMENT <gregory.clement@free-electrons.com>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2.  This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ *
+ * Maintainer: Gregory CLEMENT <gregory.clement@free-electrons.com>
+ */
+
+#include <linux/cpu_pm.h>
+#include <linux/cpuidle.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/suspend.h>
+#include <linux/platform_device.h>
+#include <asm/cpuidle.h>
+
+#define MVEBU_V7_FLAG_DEEP_IDLE	0x10000
+
+static int (*mvebu_v7_cpu_suspend)(int);
+
+static int mvebu_v7_enter_idle(struct cpuidle_device *dev,
+				struct cpuidle_driver *drv,
+				int index)
+{
+	int ret;
+	bool deepidle = false;
+	cpu_pm_enter();
+
+	if (drv->states[index].flags & MVEBU_V7_FLAG_DEEP_IDLE)
+		deepidle = true;
+
+	ret = mvebu_v7_cpu_suspend(deepidle);
+	cpu_pm_exit();
+
+	if (ret)
+		return ret;
+
+	return index;
+}
+
+static struct cpuidle_driver armadaxp_idle_driver = {
+	.name			= "armada_xp_idle",
+	.states[0]		= ARM_CPUIDLE_WFI_STATE,
+	.states[1]		= {
+		.enter			= mvebu_v7_enter_idle,
+		.exit_latency		= 10,
+		.power_usage		= 50,
+		.target_residency	= 100,
+		.flags			= CPUIDLE_FLAG_TIME_VALID,
+		.name			= "MV CPU IDLE",
+		.desc			= "CPU power down",
+	},
+	.states[2]		= {
+		.enter			= mvebu_v7_enter_idle,
+		.exit_latency		= 100,
+		.power_usage		= 5,
+		.target_residency	= 1000,
+		.flags			= CPUIDLE_FLAG_TIME_VALID |
+						MVEBU_V7_FLAG_DEEP_IDLE,
+		.name			= "MV CPU DEEP IDLE",
+		.desc			= "CPU and L2 Fabric power down",
+	},
+	.state_count = 3,
+};
+
+static struct cpuidle_driver armada370_idle_driver = {
+	.name			= "armada_370_idle",
+	.states[0]		= ARM_CPUIDLE_WFI_STATE,
+	.states[1]		= {
+		.enter			= mvebu_v7_enter_idle,
+		.exit_latency		= 100,
+		.power_usage		= 5,
+		.target_residency	= 1000,
+		.flags			= (CPUIDLE_FLAG_TIME_VALID |
+					   MVEBU_V7_FLAG_DEEP_IDLE),
+		.name			= "Deep Idle",
+		.desc			= "CPU and L2 Fabric power down",
+	},
+	.state_count = 2,
+};
+
+static struct cpuidle_driver armada38x_idle_driver = {
+	.name			= "armada_38x_idle",
+	.states[0]		= ARM_CPUIDLE_WFI_STATE,
+	.states[1]		= {
+		.enter			= mvebu_v7_enter_idle,
+		.exit_latency		= 10,
+		.power_usage		= 5,
+		.target_residency	= 100,
+		.flags			= CPUIDLE_FLAG_TIME_VALID,
+		.name			= "Idle",
+		.desc			= "CPU and SCU power down",
+	},
+	.state_count = 2,
+};
+
+static int mvebu_v7_cpuidle_probe(struct platform_device *pdev)
+{
+	mvebu_v7_cpu_suspend = pdev->dev.platform_data;
+
+	if (!strcmp(pdev->dev.driver->name, "cpuidle-armada-xp"))
+		return cpuidle_register(&armadaxp_idle_driver, NULL);
+	else if (!strcmp(pdev->dev.driver->name, "cpuidle-armada-370"))
+		return cpuidle_register(&armada370_idle_driver, NULL);
+	else if (!strcmp(pdev->dev.driver->name, "cpuidle-armada-38x"))
+		return cpuidle_register(&armada38x_idle_driver, NULL);
+	else
+		return -EINVAL;
+}
+
+static struct platform_driver armadaxp_cpuidle_plat_driver = {
+	.driver = {
+		.name = "cpuidle-armada-xp",
+		.owner = THIS_MODULE,
+	},
+	.probe = mvebu_v7_cpuidle_probe,
+};
+
+module_platform_driver(armadaxp_cpuidle_plat_driver);
+
+static struct platform_driver armada370_cpuidle_plat_driver = {
+	.driver = {
+		.name = "cpuidle-armada-370",
+		.owner = THIS_MODULE,
+	},
+	.probe = mvebu_v7_cpuidle_probe,
+};
+
+module_platform_driver(armada370_cpuidle_plat_driver);
+
+static struct platform_driver armada38x_cpuidle_plat_driver = {
+	.driver = {
+		.name = "cpuidle-armada-38x",
+		.owner = THIS_MODULE,
+	},
+	.probe = mvebu_v7_cpuidle_probe,
+};
+
+module_platform_driver(armada38x_cpuidle_plat_driver);
+
+MODULE_AUTHOR("Gregory CLEMENT <gregory.clement@free-electrons.com>");
+MODULE_DESCRIPTION("Marvell EBU v7 cpuidle driver");
+MODULE_LICENSE("GPL");

drivers/cpuidle/cpuidle-powernv.c

@@ -0,0 +1,271 @@
+/*
+ *  cpuidle-powernv - idle state cpuidle driver.
+ *  Adapted from drivers/cpuidle/cpuidle-pseries
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/moduleparam.h>
+#include <linux/cpuidle.h>
+#include <linux/cpu.h>
+#include <linux/notifier.h>
+#include <linux/clockchips.h>
+#include <linux/of.h>
+
+#include <asm/machdep.h>
+#include <asm/firmware.h>
+#include <asm/runlatch.h>
+
+/* Flags and constants used in PowerNV platform */
+
+#define MAX_POWERNV_IDLE_STATES	8
+#define IDLE_USE_INST_NAP	0x00010000 /* Use nap instruction */
+#define IDLE_USE_INST_SLEEP	0x00020000 /* Use sleep instruction */
+
+struct cpuidle_driver powernv_idle_driver = {
+	.name             = "powernv_idle",
+	.owner            = THIS_MODULE,
+};
+
+static int max_idle_state;
+static struct cpuidle_state *cpuidle_state_table;
+
+static int snooze_loop(struct cpuidle_device *dev,
+			struct cpuidle_driver *drv,
+			int index)
+{
+	local_irq_enable();
+	set_thread_flag(TIF_POLLING_NRFLAG);
+
+	ppc64_runlatch_off();
+	while (!need_resched()) {
+		HMT_low();
+		HMT_very_low();
+	}
+
+	HMT_medium();
+	ppc64_runlatch_on();
+	clear_thread_flag(TIF_POLLING_NRFLAG);
+	smp_mb();
+	return index;
+}
+
+static int nap_loop(struct cpuidle_device *dev,
+			struct cpuidle_driver *drv,
+			int index)
+{
+	ppc64_runlatch_off();
+	power7_idle();
+	ppc64_runlatch_on();
+	return index;
+}
+
+static int fastsleep_loop(struct cpuidle_device *dev,
+				struct cpuidle_driver *drv,
+				int index)
+{
+	unsigned long old_lpcr = mfspr(SPRN_LPCR);
+	unsigned long new_lpcr;
+
+	if (unlikely(system_state < SYSTEM_RUNNING))
+		return index;
+
+	new_lpcr = old_lpcr;
+	/* Do not exit powersave upon decrementer as we've setup the timer
+	 * offload.
+	 */
+	new_lpcr &= ~LPCR_PECE1;
+
+	mtspr(SPRN_LPCR, new_lpcr);
+	power7_sleep();
+
+	mtspr(SPRN_LPCR, old_lpcr);
+
+	return index;
+}
+
+/*
+ * States for dedicated partition case.
+ */
+static struct cpuidle_state powernv_states[MAX_POWERNV_IDLE_STATES] = {
+	{ /* Snooze */
+		.name = "snooze",
+		.desc = "snooze",
+		.flags = CPUIDLE_FLAG_TIME_VALID,
+		.exit_latency = 0,
+		.target_residency = 0,
+		.enter = &snooze_loop },
+};
+
+static int powernv_cpuidle_add_cpu_notifier(struct notifier_block *n,
+			unsigned long action, void *hcpu)
+{
+	int hotcpu = (unsigned long)hcpu;
+	struct cpuidle_device *dev =
+				per_cpu(cpuidle_devices, hotcpu);
+
+	if (dev && cpuidle_get_driver()) {
+		switch (action) {
+		case CPU_ONLINE:
+		case CPU_ONLINE_FROZEN:
+			cpuidle_pause_and_lock();
+			cpuidle_enable_device(dev);
+			cpuidle_resume_and_unlock();
+			break;
+
+		case CPU_DEAD:
+		case CPU_DEAD_FROZEN:
+			cpuidle_pause_and_lock();
+			cpuidle_disable_device(dev);
+			cpuidle_resume_and_unlock();
+			break;
+
+		default:
+			return NOTIFY_DONE;
+		}
+	}
+	return NOTIFY_OK;
+}
+
+static struct notifier_block setup_hotplug_notifier = {
+	.notifier_call = powernv_cpuidle_add_cpu_notifier,
+};
+
+/*
+ * powernv_cpuidle_driver_init()
+ */
+static int powernv_cpuidle_driver_init(void)
+{
+	int idle_state;
+	struct cpuidle_driver *drv = &powernv_idle_driver;
+
+	drv->state_count = 0;
+
+	for (idle_state = 0; idle_state < max_idle_state; ++idle_state) {
+		/* Is the state not enabled? */
+		if (cpuidle_state_table[idle_state].enter == NULL)
+			continue;
+
+		drv->states[drv->state_count] =	/* structure copy */
+			cpuidle_state_table[idle_state];
+
+		drv->state_count += 1;
+	}
+
+	return 0;
+}
+
+static int powernv_add_idle_states(void)
+{
+	struct device_node *power_mgt;
+	int nr_idle_states = 1; /* Snooze */
+	int dt_idle_states;
+	const __be32 *idle_state_flags;
+	const __be32 *idle_state_latency;
+	u32 len_flags, flags, latency_ns;
+	int i;
+
+	/* Currently we have snooze statically defined */
+
+	power_mgt = of_find_node_by_path("/ibm,opal/power-mgt");
+	if (!power_mgt) {
+		pr_warn("opal: PowerMgmt Node not found\n");
+		return nr_idle_states;
+	}
+
+	idle_state_flags = of_get_property(power_mgt, "ibm,cpu-idle-state-flags", &len_flags);
+	if (!idle_state_flags) {
+		pr_warn("DT-PowerMgmt: missing ibm,cpu-idle-state-flags\n");
+		return nr_idle_states;
+	}
+
+	idle_state_latency = of_get_property(power_mgt,
+			"ibm,cpu-idle-state-latencies-ns", NULL);
+	if (!idle_state_latency) {
+		pr_warn("DT-PowerMgmt: missing ibm,cpu-idle-state-latencies-ns\n");
+		return nr_idle_states;
+	}
+
+	dt_idle_states = len_flags / sizeof(u32);
+
+	for (i = 0; i < dt_idle_states; i++) {
+
+		flags = be32_to_cpu(idle_state_flags[i]);
+
+		/* Cpuidle accepts exit_latency in us and we estimate
+		 * target residency to be 10x exit_latency
+		 */
+		latency_ns = be32_to_cpu(idle_state_latency[i]);
+		if (flags & IDLE_USE_INST_NAP) {
+			/* Add NAP state */
+			strcpy(powernv_states[nr_idle_states].name, "Nap");
+			strcpy(powernv_states[nr_idle_states].desc, "Nap");
+			powernv_states[nr_idle_states].flags = CPUIDLE_FLAG_TIME_VALID;
+			powernv_states[nr_idle_states].exit_latency =
+					((unsigned int)latency_ns) / 1000;
+			powernv_states[nr_idle_states].target_residency =
+					((unsigned int)latency_ns / 100);
+			powernv_states[nr_idle_states].enter = &nap_loop;
+			nr_idle_states++;
+		}
+
+		if (flags & IDLE_USE_INST_SLEEP) {
+			/* Add FASTSLEEP state */
+			strcpy(powernv_states[nr_idle_states].name, "FastSleep");
+			strcpy(powernv_states[nr_idle_states].desc, "FastSleep");
+			powernv_states[nr_idle_states].flags =
+				CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_TIMER_STOP;
+			powernv_states[nr_idle_states].exit_latency =
+					((unsigned int)latency_ns) / 1000;
+			powernv_states[nr_idle_states].target_residency =
+					((unsigned int)latency_ns / 100);
+			powernv_states[nr_idle_states].enter = &fastsleep_loop;
+			nr_idle_states++;
+		}
+	}
+
+	return nr_idle_states;
+}
+
+/*
+ * powernv_idle_probe()
+ * Choose state table for shared versus dedicated partition
+ */
+static int powernv_idle_probe(void)
+{
+	if (cpuidle_disable != IDLE_NO_OVERRIDE)
+		return -ENODEV;
+
+	if (firmware_has_feature(FW_FEATURE_OPALv3)) {
+		cpuidle_state_table = powernv_states;
+		/* Device tree can indicate more idle states */
+		max_idle_state = powernv_add_idle_states();
+ 	} else
+ 		return -ENODEV;
+
+	return 0;
+}
+
+static int __init powernv_processor_idle_init(void)
+{
+	int retval;
+
+	retval = powernv_idle_probe();
+	if (retval)
+		return retval;
+
+	powernv_cpuidle_driver_init();
+	retval = cpuidle_register(&powernv_idle_driver, NULL);
+	if (retval) {
+		printk(KERN_DEBUG "Registration of powernv driver failed.\n");
+		return retval;
+	}
+
+	register_cpu_notifier(&setup_hotplug_notifier);
+	printk(KERN_DEBUG "powernv_idle_driver registered\n");
+	return 0;
+}
+
+device_initcall(powernv_processor_idle_init);

drivers/cpuidle/cpuidle-pseries.c

@@ -0,0 +1,273 @@
+/*
+ *  cpuidle-pseries - idle state cpuidle driver.
+ *  Adapted from drivers/idle/intel_idle.c and
+ *  drivers/acpi/processor_idle.c
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/moduleparam.h>
+#include <linux/cpuidle.h>
+#include <linux/cpu.h>
+#include <linux/notifier.h>
+
+#include <asm/paca.h>
+#include <asm/reg.h>
+#include <asm/machdep.h>
+#include <asm/firmware.h>
+#include <asm/runlatch.h>
+#include <asm/plpar_wrappers.h>
+
+struct cpuidle_driver pseries_idle_driver = {
+	.name             = "pseries_idle",
+	.owner            = THIS_MODULE,
+};
+
+static int max_idle_state;
+static struct cpuidle_state *cpuidle_state_table;
+
+static inline void idle_loop_prolog(unsigned long *in_purr)
+{
+	ppc64_runlatch_off();
+	*in_purr = mfspr(SPRN_PURR);
+	/*
+	 * Indicate to the HV that we are idle. Now would be
+	 * a good time to find other work to dispatch.
+	 */
+	get_lppaca()->idle = 1;
+}
+
+static inline void idle_loop_epilog(unsigned long in_purr)
+{
+	u64 wait_cycles;
+
+	wait_cycles = be64_to_cpu(get_lppaca()->wait_state_cycles);
+	wait_cycles += mfspr(SPRN_PURR) - in_purr;
+	get_lppaca()->wait_state_cycles = cpu_to_be64(wait_cycles);
+	get_lppaca()->idle = 0;
+
+	if (irqs_disabled())
+		local_irq_enable();
+	ppc64_runlatch_on();
+}
+
+static int snooze_loop(struct cpuidle_device *dev,
+			struct cpuidle_driver *drv,
+			int index)
+{
+	unsigned long in_purr;
+
+	idle_loop_prolog(&in_purr);
+	local_irq_enable();
+	set_thread_flag(TIF_POLLING_NRFLAG);
+
+	while (!need_resched()) {
+		HMT_low();
+		HMT_very_low();
+	}
+
+	HMT_medium();
+	clear_thread_flag(TIF_POLLING_NRFLAG);
+	smp_mb();
+
+	idle_loop_epilog(in_purr);
+
+	return index;
+}
+
+static void check_and_cede_processor(void)
+{
+	/*
+	 * Ensure our interrupt state is properly tracked,
+	 * also checks if no interrupt has occurred while we
+	 * were soft-disabled
+	 */
+	if (prep_irq_for_idle()) {
+		cede_processor();
+#ifdef CONFIG_TRACE_IRQFLAGS
+		/* Ensure that H_CEDE returns with IRQs on */
+		if (WARN_ON(!(mfmsr() & MSR_EE)))
+			__hard_irq_enable();
+#endif
+	}
+}
+
+static int dedicated_cede_loop(struct cpuidle_device *dev,
+				struct cpuidle_driver *drv,
+				int index)
+{
+	unsigned long in_purr;
+
+	idle_loop_prolog(&in_purr);
+	get_lppaca()->donate_dedicated_cpu = 1;
+
+	HMT_medium();
+	check_and_cede_processor();
+
+	get_lppaca()->donate_dedicated_cpu = 0;
+
+	idle_loop_epilog(in_purr);
+
+	return index;
+}
+
+static int shared_cede_loop(struct cpuidle_device *dev,
+			struct cpuidle_driver *drv,
+			int index)
+{
+	unsigned long in_purr;
+
+	idle_loop_prolog(&in_purr);
+
+	/*
+	 * Yield the processor to the hypervisor.  We return if
+	 * an external interrupt occurs (which are driven prior
+	 * to returning here) or if a prod occurs from another
+	 * processor. When returning here, external interrupts
+	 * are enabled.
+	 */
+	check_and_cede_processor();
+
+	idle_loop_epilog(in_purr);
+
+	return index;
+}
+
+/*
+ * States for dedicated partition case.
+ */
+static struct cpuidle_state dedicated_states[] = {
+	{ /* Snooze */
+		.name = "snooze",
+		.desc = "snooze",
+		.flags = CPUIDLE_FLAG_TIME_VALID,
+		.exit_latency = 0,
+		.target_residency = 0,
+		.enter = &snooze_loop },
+	{ /* CEDE */
+		.name = "CEDE",
+		.desc = "CEDE",
+		.flags = CPUIDLE_FLAG_TIME_VALID,
+		.exit_latency = 10,
+		.target_residency = 100,
+		.enter = &dedicated_cede_loop },
+};
+
+/*
+ * States for shared partition case.
+ */
+static struct cpuidle_state shared_states[] = {
+	{ /* Shared Cede */
+		.name = "Shared Cede",
+		.desc = "Shared Cede",
+		.flags = CPUIDLE_FLAG_TIME_VALID,
+		.exit_latency = 0,
+		.target_residency = 0,
+		.enter = &shared_cede_loop },
+};
+
+static int pseries_cpuidle_add_cpu_notifier(struct notifier_block *n,
+			unsigned long action, void *hcpu)
+{
+	int hotcpu = (unsigned long)hcpu;
+	struct cpuidle_device *dev =
+				per_cpu(cpuidle_devices, hotcpu);
+
+	if (dev && cpuidle_get_driver()) {
+		switch (action) {
+		case CPU_ONLINE:
+		case CPU_ONLINE_FROZEN:
+			cpuidle_pause_and_lock();
+			cpuidle_enable_device(dev);
+			cpuidle_resume_and_unlock();
+			break;
+
+		case CPU_DEAD:
+		case CPU_DEAD_FROZEN:
+			cpuidle_pause_and_lock();
+			cpuidle_disable_device(dev);
+			cpuidle_resume_and_unlock();
+			break;
+
+		default:
+			return NOTIFY_DONE;
+		}
+	}
+	return NOTIFY_OK;
+}
+
+static struct notifier_block setup_hotplug_notifier = {
+	.notifier_call = pseries_cpuidle_add_cpu_notifier,
+};
+
+/*
+ * pseries_cpuidle_driver_init()
+ */
+static int pseries_cpuidle_driver_init(void)
+{
+	int idle_state;
+	struct cpuidle_driver *drv = &pseries_idle_driver;
+
+	drv->state_count = 0;
+
+	for (idle_state = 0; idle_state < max_idle_state; ++idle_state) {
+		/* Is the state not enabled? */
+		if (cpuidle_state_table[idle_state].enter == NULL)
+			continue;
+
+		drv->states[drv->state_count] =	/* structure copy */
+			cpuidle_state_table[idle_state];
+
+		drv->state_count += 1;
+	}
+
+	return 0;
+}
+
+/*
+ * pseries_idle_probe()
+ * Choose state table for shared versus dedicated partition
+ */
+static int pseries_idle_probe(void)
+{
+
+	if (cpuidle_disable != IDLE_NO_OVERRIDE)
+		return -ENODEV;
+
+	if (firmware_has_feature(FW_FEATURE_SPLPAR)) {
+		if (lppaca_shared_proc(get_lppaca())) {
+			cpuidle_state_table = shared_states;
+			max_idle_state = ARRAY_SIZE(shared_states);
+		} else {
+			cpuidle_state_table = dedicated_states;
+			max_idle_state = ARRAY_SIZE(dedicated_states);
+		}
+	} else
+		return -ENODEV;
+
+	return 0;
+}
+
+static int __init pseries_processor_idle_init(void)
+{
+	int retval;
+
+	retval = pseries_idle_probe();
+	if (retval)
+		return retval;
+
+	pseries_cpuidle_driver_init();
+	retval = cpuidle_register(&pseries_idle_driver, NULL);
+	if (retval) {
+		printk(KERN_DEBUG "Registration of pseries driver failed.\n");
+		return retval;
+	}
+
+	register_cpu_notifier(&setup_hotplug_notifier);
+	printk(KERN_DEBUG "pseries_idle_driver registered\n");
+	return 0;
+}
+
+device_initcall(pseries_processor_idle_init);

drivers/cpuidle/cpuidle-ux500.c

@@ -0,0 +1,131 @@
+/*
+ * Copyright (c) 2012 Linaro : Daniel Lezcano <daniel.lezcano@linaro.org> (IBM)
+ *
+ * Based on the work of Rickard Andersson <rickard.andersson@stericsson.com>
+ * and Jonas Aaberg <jonas.aberg@stericsson.com>.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/module.h>
+#include <linux/cpuidle.h>
+#include <linux/spinlock.h>
+#include <linux/atomic.h>
+#include <linux/smp.h>
+#include <linux/mfd/dbx500-prcmu.h>
+#include <linux/platform_data/arm-ux500-pm.h>
+#include <linux/platform_device.h>
+
+#include <asm/cpuidle.h>
+#include <asm/proc-fns.h>
+
+static atomic_t master = ATOMIC_INIT(0);
+static DEFINE_SPINLOCK(master_lock);
+
+static inline int ux500_enter_idle(struct cpuidle_device *dev,
+				   struct cpuidle_driver *drv, int index)
+{
+	int this_cpu = smp_processor_id();
+	bool recouple = false;
+
+	if (atomic_inc_return(&master) == num_online_cpus()) {
+
+		/* With this lock, we prevent the other cpu to exit and enter
+		 * this function again and become the master */
+		if (!spin_trylock(&master_lock))
+			goto wfi;
+
+		/* decouple the gic from the A9 cores */
+		if (prcmu_gic_decouple()) {
+			spin_unlock(&master_lock);
+			goto out;
+		}
+
+		/* If an error occur, we will have to recouple the gic
+		 * manually */
+		recouple = true;
+
+		/* At this state, as the gic is decoupled, if the other
+		 * cpu is in WFI, we have the guarantee it won't be wake
+		 * up, so we can safely go to retention */
+		if (!prcmu_is_cpu_in_wfi(this_cpu ? 0 : 1))
+			goto out;
+
+		/* The prcmu will be in charge of watching the interrupts
+		 * and wake up the cpus */
+		if (prcmu_copy_gic_settings())
+			goto out;
+
+		/* Check in the meantime an interrupt did
+		 * not occur on the gic ... */
+		if (prcmu_gic_pending_irq())
+			goto out;
+
+		/* ... and the prcmu */
+		if (prcmu_pending_irq())
+			goto out;
+
+		/* Go to the retention state, the prcmu will wait for the
+		 * cpu to go WFI and this is what happens after exiting this
+		 * 'master' critical section */
+		if (prcmu_set_power_state(PRCMU_AP_IDLE, true, true))
+			goto out;
+
+		/* When we switch to retention, the prcmu is in charge
+		 * of recoupling the gic automatically */
+		recouple = false;
+
+		spin_unlock(&master_lock);
+	}
+wfi:
+	cpu_do_idle();
+out:
+	atomic_dec(&master);
+
+	if (recouple) {
+		prcmu_gic_recouple();
+		spin_unlock(&master_lock);
+	}
+
+	return index;
+}
+
+static struct cpuidle_driver ux500_idle_driver = {
+	.name = "ux500_idle",
+	.owner = THIS_MODULE,
+	.states = {
+		ARM_CPUIDLE_WFI_STATE,
+		{
+			.enter		  = ux500_enter_idle,
+			.exit_latency	  = 70,
+			.target_residency = 260,
+			.flags		  = CPUIDLE_FLAG_TIME_VALID |
+			                    CPUIDLE_FLAG_TIMER_STOP,
+			.name		  = "ApIdle",
+			.desc		  = "ARM Retention",
+		},
+	},
+	.safe_state_index = 0,
+	.state_count = 2,
+};
+
+static int dbx500_cpuidle_probe(struct platform_device *pdev)
+{
+	/* Configure wake up reasons */
+	prcmu_enable_wakeups(PRCMU_WAKEUP(ARM) | PRCMU_WAKEUP(RTC) |
+			     PRCMU_WAKEUP(ABB));
+
+	return cpuidle_register(&ux500_idle_driver, NULL);
+}
+
+static struct platform_driver dbx500_cpuidle_plat_driver = {
+	.driver = {
+		.name = "cpuidle-dbx500",
+		.owner = THIS_MODULE,
+	},
+	.probe = dbx500_cpuidle_probe,
+};
+
+module_platform_driver(dbx500_cpuidle_plat_driver);

drivers/cpuidle/cpuidle-zynq.c

@@ -0,0 +1,80 @@
+/*
+ * Copyright (C) 2012-2013 Xilinx
+ *
+ * CPU idle support for Xilinx Zynq
+ *
+ * based on arch/arm/mach-at91/cpuidle.c
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * The cpu idle uses wait-for-interrupt and RAM self refresh in order
+ * to implement two idle states -
+ * #1 wait-for-interrupt
+ * #2 wait-for-interrupt and RAM self refresh
+ *
+ * Maintainer: Michal Simek <michal.simek@xilinx.com>
+ */
+
+#include <linux/init.h>
+#include <linux/cpuidle.h>
+#include <linux/platform_device.h>
+#include <asm/proc-fns.h>
+#include <asm/cpuidle.h>
+
+#define ZYNQ_MAX_STATES		2
+
+/* Actual code that puts the SoC in different idle states */
+static int zynq_enter_idle(struct cpuidle_device *dev,
+			   struct cpuidle_driver *drv, int index)
+{
+	/* Add code for DDR self refresh start */
+	cpu_do_idle();
+
+	return index;
+}
+
+static struct cpuidle_driver zynq_idle_driver = {
+	.name = "zynq_idle",
+	.owner = THIS_MODULE,
+	.states = {
+		ARM_CPUIDLE_WFI_STATE,
+		{
+			.enter			= zynq_enter_idle,
+			.exit_latency		= 10,
+			.target_residency	= 10000,
+			.flags			= CPUIDLE_FLAG_TIME_VALID,
+			.name			= "RAM_SR",
+			.desc			= "WFI and RAM Self Refresh",
+		},
+	},
+	.safe_state_index = 0,
+	.state_count = ZYNQ_MAX_STATES,
+};
+
+/* Initialize CPU idle by registering the idle states */
+static int zynq_cpuidle_probe(struct platform_device *pdev)
+{
+	pr_info("Xilinx Zynq CpuIdle Driver started\n");
+
+	return cpuidle_register(&zynq_idle_driver, NULL);
+}
+
+static struct platform_driver zynq_cpuidle_driver = {
+	.driver = {
+		.name = "cpuidle-zynq",
+		.owner = THIS_MODULE,
+	},
+	.probe = zynq_cpuidle_probe,
+};
+
+module_platform_driver(zynq_cpuidle_driver);

drivers/cpuidle/cpuidle.c

@@ -0,0 +1,628 @@
+/*
+ * cpuidle.c - core cpuidle infrastructure
+ *
+ * (C) 2006-2007 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
+ *               Shaohua Li <shaohua.li@intel.com>
+ *               Adam Belay <abelay@novell.com>
+ *
+ * This code is licenced under the GPL.
+ */
+
+#include <linux/clockchips.h>
+#include <linux/kernel.h>
+#include <linux/mutex.h>
+#include <linux/sched.h>
+#include <linux/notifier.h>
+#include <linux/pm_qos.h>
+#include <linux/cpu.h>
+#include <linux/cpuidle.h>
+#include <linux/ktime.h>
+#include <linux/hrtimer.h>
+#include <linux/module.h>
+#include <linux/exynos-ss.h>
+#include <trace/events/power.h>
+
+#include "cpuidle.h"
+
+DEFINE_PER_CPU(struct cpuidle_device *, cpuidle_devices);
+DEFINE_PER_CPU(struct cpuidle_device, cpuidle_dev);
+
+DEFINE_MUTEX(cpuidle_lock);
+LIST_HEAD(cpuidle_detected_devices);
+
+static int enabled_devices;
+static int off __read_mostly;
+static int initialized __read_mostly;
+static bool use_deepest_state __read_mostly;
+
+int cpuidle_disabled(void)
+{
+	return off;
+}
+void disable_cpuidle(void)
+{
+	off = 1;
+}
+
+/**
+ * cpuidle_play_dead - cpu off-lining
+ *
+ * Returns in case of an error or no driver
+ */
+int cpuidle_play_dead(void)
+{
+	struct cpuidle_device *dev = __this_cpu_read(cpuidle_devices);
+	struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev);
+	int i;
+
+	if (!drv)
+		return -ENODEV;
+
+	/* Find lowest-power state that supports long-term idle */
+	for (i = drv->state_count - 1; i >= CPUIDLE_DRIVER_STATE_START; i--)
+		if (drv->states[i].enter_dead)
+			return drv->states[i].enter_dead(dev, i);
+
+	return -ENODEV;
+}
+
+/**
+ * cpuidle_use_deepest_state - Enable/disable the "deepest idle" mode.
+ * @enable: Whether enable or disable the feature.
+ *
+ * If the "deepest idle" mode is enabled, cpuidle will ignore the governor and
+ * always use the state with the greatest exit latency (out of the states that
+ * are not disabled).
+ *
+ * This function can only be called after cpuidle_pause() to avoid races.
+ */
+void cpuidle_use_deepest_state(bool enable)
+{
+	use_deepest_state = enable;
+}
+
+/**
+ * cpuidle_find_deepest_state - Find the state of the greatest exit latency.
+ * @drv: cpuidle driver for a given CPU.
+ * @dev: cpuidle device for a given CPU.
+ */
+static int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
+				      struct cpuidle_device *dev)
+{
+	unsigned int latency_req = 0;
+	int i, ret = CPUIDLE_DRIVER_STATE_START - 1;
+
+	for (i = CPUIDLE_DRIVER_STATE_START; i < drv->state_count; i++) {
+		struct cpuidle_state *s = &drv->states[i];
+		struct cpuidle_state_usage *su = &dev->states_usage[i];
+
+		if (s->disabled || su->disable || s->exit_latency <= latency_req)
+			continue;
+
+		latency_req = s->exit_latency;
+		ret = i;
+	}
+	return ret;
+}
+
+/**
+ * cpuidle_enter_state - enter the state and update stats
+ * @dev: cpuidle device for this cpu
+ * @drv: cpuidle driver for this cpu
+ * @next_state: index into drv->states of the state to enter
+ */
+int cpuidle_enter_state(struct cpuidle_device *dev, struct cpuidle_driver *drv,
+			int index)
+{
+	int entered_state;
+
+	struct cpuidle_state *target_state = &drv->states[index];
+	ktime_t time_start, time_end;
+	s64 diff;
+
+	trace_cpu_idle_rcuidle(index, dev->cpu);
+	exynos_ss_cpuidle(index, 0, 0, ESS_FLAG_IN);
+	time_start = ktime_get();
+
+	entered_state = target_state->enter(dev, drv, index);
+
+	time_end = ktime_get();
+	exynos_ss_cpuidle(index, entered_state,
+		(int)ktime_to_us(ktime_sub(time_end, time_start)), ESS_FLAG_OUT);
+	trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, dev->cpu);
+
+	if (!cpuidle_state_is_coupled(dev, drv, entered_state))
+		local_irq_enable();
+
+	diff = ktime_to_us(ktime_sub(time_end, time_start));
+	if (diff > INT_MAX)
+		diff = INT_MAX;
+
+	dev->last_residency = (int) diff;
+
+	if (entered_state >= 0) {
+		/* Update cpuidle counters */
+		/* This can be moved to within driver enter routine
+		 * but that results in multiple copies of same code.
+		 */
+		dev->states_usage[entered_state].time += dev->last_residency;
+		dev->states_usage[entered_state].usage++;
+	} else {
+		dev->last_residency = 0;
+	}
+
+	return entered_state;
+}
+
+/**
+ * cpuidle_select - ask the cpuidle framework to choose an idle state
+ *
+ * @drv: the cpuidle driver
+ * @dev: the cpuidle device
+ *
+ * Returns the index of the idle state.
+ */
+int cpuidle_select(struct cpuidle_driver *drv, struct cpuidle_device *dev)
+{
+	if (off || !initialized)
+		return -ENODEV;
+
+	if (!drv || !dev || !dev->enabled)
+		return -EBUSY;
+
+	if (unlikely(use_deepest_state))
+		return cpuidle_find_deepest_state(drv, dev);
+
+	return cpuidle_curr_governor->select(drv, dev);
+}
+
+/**
+ * cpuidle_enter - enter into the specified idle state
+ *
+ * @drv:   the cpuidle driver tied with the cpu
+ * @dev:   the cpuidle device
+ * @index: the index in the idle state table
+ *
+ * Returns the index in the idle state, < 0 in case of error.
+ * The error code depends on the backend driver
+ */
+int cpuidle_enter(struct cpuidle_driver *drv, struct cpuidle_device *dev,
+		  int index)
+{
+	if (cpuidle_state_is_coupled(dev, drv, index))
+		return cpuidle_enter_state_coupled(dev, drv, index);
+	return cpuidle_enter_state(dev, drv, index);
+}
+
+/**
+ * cpuidle_reflect - tell the underlying governor what was the state
+ * we were in
+ *
+ * @dev  : the cpuidle device
+ * @index: the index in the idle state table
+ *
+ */
+void cpuidle_reflect(struct cpuidle_device *dev, int index)
+{
+	if (cpuidle_curr_governor->reflect && !unlikely(use_deepest_state))
+		cpuidle_curr_governor->reflect(dev, index);
+}
+
+/**
+ * cpuidle_install_idle_handler - installs the cpuidle idle loop handler
+ */
+void cpuidle_install_idle_handler(void)
+{
+	if (enabled_devices) {
+		/* Make sure all changes finished before we switch to new idle */
+		smp_wmb();
+		initialized = 1;
+	}
+}
+
+/**
+ * cpuidle_uninstall_idle_handler - uninstalls the cpuidle idle loop handler
+ */
+void cpuidle_uninstall_idle_handler(void)
+{
+	if (enabled_devices) {
+		initialized = 0;
+		wake_up_all_idle_cpus();
+	}
+
+	/*
+	 * Make sure external observers (such as the scheduler)
+	 * are done looking at pointed idle states.
+	 */
+	synchronize_rcu();
+}
+
+/**
+ * cpuidle_pause_and_lock - temporarily disables CPUIDLE
+ */
+void cpuidle_pause_and_lock(void)
+{
+	mutex_lock(&cpuidle_lock);
+	cpuidle_uninstall_idle_handler();
+}
+
+EXPORT_SYMBOL_GPL(cpuidle_pause_and_lock);
+
+/**
+ * cpuidle_resume_and_unlock - resumes CPUIDLE operation
+ */
+void cpuidle_resume_and_unlock(void)
+{
+	cpuidle_install_idle_handler();
+	mutex_unlock(&cpuidle_lock);
+}
+
+EXPORT_SYMBOL_GPL(cpuidle_resume_and_unlock);
+
+/* Currently used in suspend/resume path to suspend cpuidle */
+void cpuidle_pause(void)
+{
+	mutex_lock(&cpuidle_lock);
+	cpuidle_uninstall_idle_handler();
+	mutex_unlock(&cpuidle_lock);
+}
+
+/* Currently used in suspend/resume path to resume cpuidle */
+void cpuidle_resume(void)
+{
+	mutex_lock(&cpuidle_lock);
+	cpuidle_install_idle_handler();
+	mutex_unlock(&cpuidle_lock);
+}
+
+/**
+ * cpuidle_enable_device - enables idle PM for a CPU
+ * @dev: the CPU
+ *
+ * This function must be called between cpuidle_pause_and_lock and
+ * cpuidle_resume_and_unlock when used externally.
+ */
+int cpuidle_enable_device(struct cpuidle_device *dev)
+{
+	int ret;
+	struct cpuidle_driver *drv;
+
+	if (!dev)
+		return -EINVAL;
+
+	if (dev->enabled)
+		return 0;
+
+	drv = cpuidle_get_cpu_driver(dev);
+
+	if (!drv || !cpuidle_curr_governor)
+		return -EIO;
+
+	if (!dev->registered)
+		return -EINVAL;
+
+	ret = cpuidle_add_device_sysfs(dev);
+	if (ret)
+		return ret;
+
+	if (cpuidle_curr_governor->enable &&
+	    (ret = cpuidle_curr_governor->enable(drv, dev)))
+		goto fail_sysfs;
+
+	smp_wmb();
+
+	dev->enabled = 1;
+
+	enabled_devices++;
+	return 0;
+
+fail_sysfs:
+	cpuidle_remove_device_sysfs(dev);
+
+	return ret;
+}
+
+EXPORT_SYMBOL_GPL(cpuidle_enable_device);
+
+/**
+ * cpuidle_disable_device - disables idle PM for a CPU
+ * @dev: the CPU
+ *
+ * This function must be called between cpuidle_pause_and_lock and
+ * cpuidle_resume_and_unlock when used externally.
+ */
+void cpuidle_disable_device(struct cpuidle_device *dev)
+{
+	struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev);
+
+	if (!dev || !dev->enabled)
+		return;
+
+	if (!drv || !cpuidle_curr_governor)
+		return;
+
+	dev->enabled = 0;
+
+	if (cpuidle_curr_governor->disable)
+		cpuidle_curr_governor->disable(drv, dev);
+
+	cpuidle_remove_device_sysfs(dev);
+	enabled_devices--;
+}
+
+EXPORT_SYMBOL_GPL(cpuidle_disable_device);
+
+static void __cpuidle_unregister_device(struct cpuidle_device *dev)
+{
+	struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev);
+
+	list_del(&dev->device_list);
+	per_cpu(cpuidle_devices, dev->cpu) = NULL;
+	module_put(drv->owner);
+}
+
+static void __cpuidle_device_init(struct cpuidle_device *dev)
+{
+	memset(dev->states_usage, 0, sizeof(dev->states_usage));
+	dev->last_residency = 0;
+}
+
+/**
+ * __cpuidle_register_device - internal register function called before register
+ * and enable routines
+ * @dev: the cpu
+ *
+ * cpuidle_lock mutex must be held before this is called
+ */
+static int __cpuidle_register_device(struct cpuidle_device *dev)
+{
+	int ret;
+	struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev);
+
+	if (!try_module_get(drv->owner))
+		return -EINVAL;
+
+	per_cpu(cpuidle_devices, dev->cpu) = dev;
+	list_add(&dev->device_list, &cpuidle_detected_devices);
+
+	ret = cpuidle_coupled_register_device(dev);
+	if (ret)
+		__cpuidle_unregister_device(dev);
+	else
+		dev->registered = 1;
+
+	return ret;
+}
+
+/**
+ * cpuidle_register_device - registers a CPU's idle PM feature
+ * @dev: the cpu
+ */
+int cpuidle_register_device(struct cpuidle_device *dev)
+{
+	int ret = -EBUSY;
+
+	if (!dev)
+		return -EINVAL;
+
+	mutex_lock(&cpuidle_lock);
+
+	if (dev->registered)
+		goto out_unlock;
+
+	__cpuidle_device_init(dev);
+
+	ret = __cpuidle_register_device(dev);
+	if (ret)
+		goto out_unlock;
+
+	ret = cpuidle_add_sysfs(dev);
+	if (ret)
+		goto out_unregister;
+
+	ret = cpuidle_enable_device(dev);
+	if (ret)
+		goto out_sysfs;
+
+	cpuidle_install_idle_handler();
+
+out_unlock:
+	mutex_unlock(&cpuidle_lock);
+
+	return ret;
+
+out_sysfs:
+	cpuidle_remove_sysfs(dev);
+out_unregister:
+	__cpuidle_unregister_device(dev);
+	goto out_unlock;
+}
+
+EXPORT_SYMBOL_GPL(cpuidle_register_device);
+
+/**
+ * cpuidle_unregister_device - unregisters a CPU's idle PM feature
+ * @dev: the cpu
+ */
+void cpuidle_unregister_device(struct cpuidle_device *dev)
+{
+	if (!dev || dev->registered == 0)
+		return;
+
+	cpuidle_pause_and_lock();
+
+	cpuidle_disable_device(dev);
+
+	cpuidle_remove_sysfs(dev);
+
+	__cpuidle_unregister_device(dev);
+
+	cpuidle_coupled_unregister_device(dev);
+
+	cpuidle_resume_and_unlock();
+}
+
+EXPORT_SYMBOL_GPL(cpuidle_unregister_device);
+
+/**
+ * cpuidle_unregister: unregister a driver and the devices. This function
+ * can be used only if the driver has been previously registered through
+ * the cpuidle_register function.
+ *
+ * @drv: a valid pointer to a struct cpuidle_driver
+ */
+void cpuidle_unregister(struct cpuidle_driver *drv)
+{
+	int cpu;
+	struct cpuidle_device *device;
+
+	for_each_cpu(cpu, drv->cpumask) {
+		device = &per_cpu(cpuidle_dev, cpu);
+		cpuidle_unregister_device(device);
+	}
+
+	cpuidle_unregister_driver(drv);
+}
+EXPORT_SYMBOL_GPL(cpuidle_unregister);
+
+/**
+ * cpuidle_register: registers the driver and the cpu devices with the
+ * coupled_cpus passed as parameter. This function is used for all common
+ * initialization pattern there are in the arch specific drivers. The
+ * devices is globally defined in this file.
+ *
+ * @drv         : a valid pointer to a struct cpuidle_driver
+ * @coupled_cpus: a cpumask for the coupled states
+ *
+ * Returns 0 on success, < 0 otherwise
+ */
+int cpuidle_register(struct cpuidle_driver *drv,
+		     const struct cpumask *const coupled_cpus)
+{
+	int ret, cpu;
+	struct cpuidle_device *device;
+
+	ret = cpuidle_register_driver(drv);
+	if (ret) {
+		pr_err("failed to register cpuidle driver\n");
+		return ret;
+	}
+
+	for_each_cpu(cpu, drv->cpumask) {
+		device = &per_cpu(cpuidle_dev, cpu);
+		device->cpu = cpu;
+
+#ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
+		/*
+		 * On multiplatform for ARM, the coupled idle states could be
+		 * enabled in the kernel even if the cpuidle driver does not
+		 * use it. Note, coupled_cpus is a struct copy.
+		 */
+		if (coupled_cpus)
+			device->coupled_cpus = *coupled_cpus;
+#endif
+		ret = cpuidle_register_device(device);
+		if (!ret)
+			continue;
+
+		pr_err("Failed to register cpuidle device for cpu%d\n", cpu);
+
+		cpuidle_unregister(drv);
+		break;
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(cpuidle_register);
+
+#ifdef CONFIG_SMP
+
+/*
+ * This function gets called when a part of the kernel has a new latency
+ * requirement.  This means we need to get all processors out of their C-state,
+ * and then recalculate a new suitable C-state. Just do a cross-cpu IPI; that
+ * wakes them all right up.
+ */
+static int cpuidle_latency_notify(struct notifier_block *b,
+		unsigned long l, void *v)
+{
+	wake_up_all_idle_cpus();
+	return NOTIFY_OK;
+}
+
+static struct notifier_block cpuidle_latency_notifier = {
+	.notifier_call = cpuidle_latency_notify,
+};
+
+static inline void latency_notifier_init(struct notifier_block *n)
+{
+	pm_qos_add_notifier(PM_QOS_CPU_DMA_LATENCY, n);
+}
+
+#else /* CONFIG_SMP */
+
+#define latency_notifier_init(x) do { } while (0)
+
+#endif /* CONFIG_SMP */
+
+#ifdef CONFIG_CPU_IDLE_STOP_IDLE_DURING_HOTPLUG
+/* during hotplug out in progress, disable cpuidle for faster hotplug out */
+static int exynos_cpuidle_hotcpu_callback(struct notifier_block *nfb,
+					unsigned long action, void *hcpu)
+{
+	unsigned int cpu = (unsigned long)hcpu;
+	struct cpuidle_device *dev = per_cpu(cpuidle_devices, cpu);
+
+	if (dev) {
+		switch (action) {
+		case CPU_ONLINE:
+			cpuidle_enable_device(dev);
+			break;
+
+		case CPU_DOWN_PREPARE:
+			cpuidle_disable_device(dev);
+			break;
+
+		case CPU_DOWN_FAILED:
+			cpuidle_enable_device(dev);
+			break;
+		}
+	}
+	return NOTIFY_OK;
+}
+
+static struct notifier_block __refdata cpuidle_hotcpu_notifier = {
+	.notifier_call = exynos_cpuidle_hotcpu_callback,
+	.priority = INT_MAX,	/* want to be called first */
+};
+
+static int __init cpuidle_hotcpu_init(void)
+{
+	register_hotcpu_notifier(&cpuidle_hotcpu_notifier);
+
+	return 0;
+}
+device_initcall(cpuidle_hotcpu_init);
+#endif
+
+/**
+ * cpuidle_init - core initializer
+ */
+static int __init cpuidle_init(void)
+{
+	int ret;
+
+	if (cpuidle_disabled())
+		return -ENODEV;
+
+	ret = cpuidle_add_interface(cpu_subsys.dev_root);
+	if (ret)
+		return ret;
+
+	latency_notifier_init(&cpuidle_latency_notifier);
+
+	return 0;
+}
+
+module_param(off, int, 0444);
+core_initcall(cpuidle_init);

drivers/cpuidle/cpuidle.h

@@ -0,0 +1,66 @@
+/*
+ * cpuidle.h - The internal header file
+ */
+
+#ifndef __DRIVER_CPUIDLE_H
+#define __DRIVER_CPUIDLE_H
+
+/* For internal use only */
+extern struct cpuidle_governor *cpuidle_curr_governor;
+extern struct list_head cpuidle_governors;
+extern struct list_head cpuidle_detected_devices;
+extern struct mutex cpuidle_lock;
+extern spinlock_t cpuidle_driver_lock;
+extern int cpuidle_disabled(void);
+extern int cpuidle_enter_state(struct cpuidle_device *dev,
+		struct cpuidle_driver *drv, int next_state);
+
+/* idle loop */
+extern void cpuidle_install_idle_handler(void);
+extern void cpuidle_uninstall_idle_handler(void);
+
+/* governors */
+extern int cpuidle_switch_governor(struct cpuidle_governor *gov);
+
+/* sysfs */
+
+struct device;
+
+extern int cpuidle_add_interface(struct device *dev);
+extern void cpuidle_remove_interface(struct device *dev);
+extern int cpuidle_add_device_sysfs(struct cpuidle_device *device);
+extern void cpuidle_remove_device_sysfs(struct cpuidle_device *device);
+extern int cpuidle_add_sysfs(struct cpuidle_device *dev);
+extern void cpuidle_remove_sysfs(struct cpuidle_device *dev);
+
+#ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
+bool cpuidle_state_is_coupled(struct cpuidle_device *dev,
+		struct cpuidle_driver *drv, int state);
+int cpuidle_enter_state_coupled(struct cpuidle_device *dev,
+		struct cpuidle_driver *drv, int next_state);
+int cpuidle_coupled_register_device(struct cpuidle_device *dev);
+void cpuidle_coupled_unregister_device(struct cpuidle_device *dev);
+#else
+static inline bool cpuidle_state_is_coupled(struct cpuidle_device *dev,
+		struct cpuidle_driver *drv, int state)
+{
+	return false;
+}
+
+static inline int cpuidle_enter_state_coupled(struct cpuidle_device *dev,
+		struct cpuidle_driver *drv, int next_state)
+{
+	return -1;
+}
+
+static inline int cpuidle_coupled_register_device(struct cpuidle_device *dev)
+{
+	return 0;
+}
+
+static inline void cpuidle_coupled_unregister_device(struct cpuidle_device *dev)
+{
+}
+#endif
+
+#endif /* __DRIVER_CPUIDLE_H */

drivers/cpuidle/cpuidle_profiler.c

@@ -0,0 +1,688 @@
+/*
+ * Copyright (c) 2015 Samsung Electronics Co., Ltd.
+ *		http://www.samsung.com
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+*/
+
+#include <linux/device.h>
+#include <linux/kobject.h>
+#include <linux/cpuidle.h>
+#include <linux/slab.h>
+#include <linux/cpuidle_profiler.h>
+
+#include <asm/page.h>
+#include <asm/cputype.h>
+#include <asm/smp_plat.h>
+#include <asm/topology.h>
+
+#include <soc/samsung/exynos-powermode.h>
+
+static bool profile_started;
+
+/*
+ * "profile_info" contains profiling data for per cpu idle state which
+ * declared in cpuidle driver.
+ */
+static DEFINE_PER_CPU(struct cpuidle_profile_info, profile_info);
+
+/*
+ * "cpd_info" contains profiling data for CPD(Cluster Power Down) which
+ * is subordinate to C2 state idle. Each cluster has one element in
+ * cpd_info[].
+ */
+static struct cpuidle_profile_info cpd_info[MAX_CLUSTER];
+
+/*
+ * "lpm_info" contains profiling data for LPM(Low Power Mode). LPM
+ * comprises many system power mode such AFTR, ALPA.
+ */
+static struct cpuidle_profile_info lpm_info;
+
+/*
+ * "idle_ip_pending" contains which blocks to enter system power mode.
+ * It is used by only SICD/SICD_CPD and ALPA.
+ */
+static int idle_ip_pending[NUM_SYS_POWERDOWN][NUM_IDLE_IP][IDLE_IP_REG_SIZE];
+
+/*
+ * "idle_ip_list" contains IP name in IDLE_IP
+ */
+char *idle_ip_list[NUM_IDLE_IP][IDLE_IP_REG_SIZE];
+
+/************************************************************************
+ *                              Profiling                               *
+ ************************************************************************/
+/*
+ * If cpu does not enter idle state, cur_state has -EINVAL. By this,
+ * profiler can be aware of cpu state.
+ */
+#define state_entered(state)	(((int)state < (int)0) ? 0 : 1)
+
+static void enter_idle_state(struct cpuidle_profile_info *info,
+					int state, ktime_t now)
+{
+	if (state_entered(info->cur_state))
+		return;
+
+	info->cur_state = state;
+	info->last_entry_time = now;
+
+	info->usage[state].entry_count++;
+}
+
+static void exit_idle_state(struct cpuidle_profile_info *info,
+					int state, ktime_t now,
+					int earlywakeup)
+{
+	s64 diff;
+
+	if (!state_entered(info->cur_state))
+		return;
+
+	info->cur_state = -EINVAL;
+
+	if (earlywakeup) {
+		/*
+		 * If cpu cannot enter power mode, residency time
+		 * should not be updated.
+		 */
+		info->usage[state].early_wakeup_count++;
+		return;
+	}
+
+	diff = ktime_to_us(ktime_sub(now, info->last_entry_time));
+	info->usage[state].time += diff;
+}
+
+/*
+ * C2 subordinate state such as CPD and SICD can be entered by many cpus.
+ * The variables which contains these idle states need to keep
+ * synchronization.
+ */
+static DEFINE_SPINLOCK(substate_lock);
+
+void __cpuidle_profile_start(int cpu, int state, int substate)
+{
+	struct cpuidle_profile_info *info = &per_cpu(profile_info, cpu);
+	ktime_t now = ktime_get();
+
+	/*
+	 * Start to profile idle state. profile_info is per-CPU variable,
+	 * it does not need to synchronization.
+	 */
+	enter_idle_state(info, state, now);
+
+	/* Start to profile subordinate idle state. */
+	if (substate) {
+		spin_lock(&substate_lock);
+
+		/*
+		 * SICD is a system power mode and also C2 subordinate
+		 * state becuase it is entered by C2 entry cpu. On this
+		 * count, in case of SICD or SICD_CPD, profiler updates
+		 * lpm_info although idle state is C2.
+		 */
+		if (state == PROFILE_C2) {
+			switch (substate) {
+			case C2_CPD:
+				info = &cpd_info[to_cluster(cpu)];
+				enter_idle_state(info, 0, now);
+				break;
+			case C2_SICD:
+				info = &lpm_info;
+				enter_idle_state(info, LPM_SICD, now);
+				break;
+#if defined(CONFIG_SOC_EXYNOS8890)
+			case C2_SICD_CPD:
+				info = &cpd_info[to_cluster(cpu)];
+				enter_idle_state(info, 0, now);
+
+				info = &lpm_info;
+				enter_idle_state(info, LPM_SICD_CPD, now);
+				break;
+#endif
+			}
+		} else if (state == PROFILE_LPM)
+			enter_idle_state(&lpm_info, substate, now);
+
+		spin_unlock(&substate_lock);
+	}
+}
+
+void cpuidle_profile_start(int cpu, int state, int substate)
+{
+	/*
+	 * Return if profile is not started
+	 */
+	if (!profile_started)
+		return;
+
+	__cpuidle_profile_start(cpu, state, substate);
+}
+
+void cpuidle_profile_start_no_substate(int cpu, int state)
+{
+	cpuidle_profile_start(cpu, state, 0);
+}
+
+void __cpuidle_profile_finish(int cpu, int earlywakeup)
+{
+	struct cpuidle_profile_info *info = &per_cpu(profile_info, cpu);
+	int state = info->cur_state;
+	ktime_t now = ktime_get();
+
+	exit_idle_state(info, state, now, earlywakeup);
+
+	spin_lock(&substate_lock);
+
+	/*
+	 * Subordinate state can be wakeup by many cpus. We cannot predict
+	 * which cpu wakeup from idle state, profiler always try to update
+	 * residency time of subordinate state. To avoid duplicate updating,
+	 * exit_idle_state() checks validation.
+	 */
+	if (has_sub_state(state)) {
+		info = &cpd_info[to_cluster(cpu)];
+		exit_idle_state(info, info->cur_state, now, earlywakeup);
+
+		info = &lpm_info;
+		exit_idle_state(info, info->cur_state, now, earlywakeup);
+	}
+
+	spin_unlock(&substate_lock);
+}
+
+void cpuidle_profile_finish(int cpu, int earlywakeup)
+{
+	/*
+	 * Return if profile is not started
+	 */
+	if (!profile_started)
+		return;
+
+	__cpuidle_profile_finish(cpu, earlywakeup);
+}
+
+void cpuidle_profile_finish_no_earlywakeup(int cpu)
+{
+	cpuidle_profile_finish(cpu, 0);
+}
+
+/*
+ * Before system enters system power mode, it checks idle-ip status. Its
+ * status is conveyed to cpuidle_profile_collect_idle_ip().
+ */
+void cpuidle_profile_collect_idle_ip(int mode, int index,
+						unsigned int idle_ip)
+{
+	int i;
+
+	/*
+	 * Return if profile is not started
+	 */
+	if (!profile_started)
+		return;
+
+	for (i = 0; i < IDLE_IP_REG_SIZE; i++) {
+		/*
+		 * If bit of idle_ip has 1, IP corresponding to its bit
+		 * is not idle.
+		 */
+		if (idle_ip & (1 << i))
+			idle_ip_pending[mode][index][i]++;
+	}
+}
+
+/************************************************************************
+ *                              Show result                             *
+ ************************************************************************/
+static ktime_t profile_start_time;
+static ktime_t profile_finish_time;
+static s64 profile_time;
+
+#if defined(CONFIG_SOC_EXYNOS7570)
+static char * sys_powerdown_str[NUM_SYS_POWERDOWN] = {
+	"SICD",
+	"AFTR",
+	"STOP",
+	"LPD",
+	"LPA",
+        "DSTOP",
+	"SLEEP"
+};
+#endif
+
+#if defined(CONFIG_SOC_EXYNOS8890)
+static char * sys_powerdown_str[NUM_SYS_POWERDOWN] = {
+	"SICD",
+	"SICD_CPD",
+	"AFTR",
+	"STOP",
+        "DSTOP",
+	"LPD",
+	"ALPA",
+	"SLEEP"
+};
+#endif
+
+#define get_sys_powerdown_str(mode)	sys_powerdown_str[mode]
+
+static int calculate_percent(s64 residency)
+{
+	if (!residency)
+		return 0;
+
+	residency *= 100;
+	do_div(residency, profile_time);
+
+	return residency;
+}
+
+static unsigned long long sum_idle_time(int cpu)
+{
+	int i;
+	unsigned long long idle_time = 0;
+	struct cpuidle_profile_info *info = &per_cpu(profile_info, cpu);
+
+	for (i = 0; i < info->state_count; i++)
+		idle_time += info->usage[i].time;
+
+	return idle_time;
+}
+
+static int total_idle_ratio(int cpu)
+{
+	return calculate_percent(sum_idle_time(cpu));
+}
+
+static void show_result(void)
+{
+	int i, idle_ip, bit, cpu;
+	struct cpuidle_profile_info *info;
+	int state_count;
+
+	pr_info("#############################################################\n");
+	pr_info("Profiling Time : %lluus\n", profile_time);
+
+	pr_info("\n");
+
+	pr_info("[total idle ratio]\n");
+	pr_info("#cpu      #time    #ratio\n");
+	for_each_possible_cpu(cpu)
+		pr_info("cpu%d %10lluus   %3u%%\n", cpu,
+			sum_idle_time(cpu), total_idle_ratio(cpu));
+
+	pr_info("\n");
+
+	/*
+	 * All profile_info has same state_count. As a representative,
+	 * cpu0's is used.
+	 */
+	state_count = per_cpu(profile_info, 0).state_count;
+
+	for (i = 0; i < state_count; i++) {
+		pr_info("[state%d]\n", i);
+		pr_info("#cpu   #entry   #early      #time    #ratio\n");
+		for_each_possible_cpu(cpu) {
+			info = &per_cpu(profile_info, cpu);
+			pr_info("cpu%d   %5u   %5u   %10lluus   %3u%%\n", cpu,
+				info->usage[i].entry_count,
+				info->usage[i].early_wakeup_count,
+				info->usage[i].time,
+				calculate_percent(info->usage[i].time));
+		}
+
+		pr_info("\n");
+	}
+
+	pr_info("[CPD] - Cluster Power Down\n");
+	pr_info("#cluster     #entry   #early      #time     #ratio\n");
+	for_each_cluster(i) {
+		pr_info("cl_%s   %5u   %5u   %10lluus    %3u%%\n",
+			i == to_cluster(0) ? "boot   " : "nonboot",
+			cpd_info[i].usage->entry_count,
+			cpd_info[i].usage->early_wakeup_count,
+			cpd_info[i].usage->time,
+			calculate_percent(cpd_info[i].usage->time));
+	}
+
+	pr_info("\n");
+
+	pr_info("[LPM] - Low Power Mode\n");
+	pr_info("#mode        #entry   #early      #time     #ratio\n");
+	for_each_syspower_mode(i) {
+		pr_info("%-9s    %5u   %5u   %10lluus    %3u%%\n",
+			get_sys_powerdown_str(i),
+			lpm_info.usage[i].entry_count,
+			lpm_info.usage[i].early_wakeup_count,
+			lpm_info.usage[i].time,
+			calculate_percent(lpm_info.usage[i].time));
+	}
+
+	pr_info("\n");
+
+	pr_info("[LPM blockers]\n");
+	for_each_syspower_mode(i) {
+		for_each_idle_ip(idle_ip) {
+			for (bit = 0; bit < IDLE_IP_REG_SIZE; bit++) {
+				if (idle_ip_pending[i][idle_ip][bit])
+					pr_info("%s block by IDLE_IP%d[%d](%s, count = %d)\n",
+						get_sys_powerdown_str(i),
+						idle_ip, bit, idle_ip_list[idle_ip][bit],
+						idle_ip_pending[i][idle_ip][bit]);
+			}
+		}
+	}
+
+	pr_info("\n");
+	pr_info("#############################################################\n");
+}
+
+/************************************************************************
+ *                            Profile control                           *
+ ************************************************************************/
+static void clear_time(ktime_t *time)
+{
+	time->tv64 = 0;
+}
+
+static void clear_profile_info(struct cpuidle_profile_info *info)
+{
+	memset(info->usage, 0,
+		sizeof(struct cpuidle_profile_state_usage) * info->state_count);
+
+	clear_time(&info->last_entry_time);
+	info->cur_state = -EINVAL;
+}
+
+static void reset_profile_record(void)
+{
+	int i;
+
+	clear_time(&profile_start_time);
+	clear_time(&profile_finish_time);
+
+	for_each_possible_cpu(i)
+		clear_profile_info(&per_cpu(profile_info, i));
+
+	for_each_cluster(i)
+		clear_profile_info(&cpd_info[i]);
+
+	clear_profile_info(&lpm_info);
+
+	memset(idle_ip_pending, 0,
+		NUM_SYS_POWERDOWN * NUM_IDLE_IP * IDLE_IP_REG_SIZE * sizeof(int));
+}
+
+static void call_cpu_start_profile(void *p) {};
+static void call_cpu_finish_profile(void *p) {};
+
+static void cpuidle_profile_main_start(void)
+{
+	if (profile_started) {
+		pr_err("cpuidle profile is ongoing\n");
+		return;
+	}
+
+	reset_profile_record();
+	profile_start_time = ktime_get();
+
+	profile_started = 1;
+
+	/* Wakeup all cpus and clear own profile data to start profile */
+	preempt_disable();
+	smp_call_function(call_cpu_start_profile, NULL, 1);
+	preempt_enable();
+
+	pr_info("cpuidle profile start\n");
+}
+
+static void cpuidle_profile_main_finish(void)
+{
+	if (!profile_started) {
+		pr_err("CPUIDLE profile does not start yet\n");
+		return;
+	}
+
+	pr_info("cpuidle profile finish\n");
+
+	/* Wakeup all cpus to update own profile data to finish profile */
+	preempt_disable();
+	smp_call_function(call_cpu_finish_profile, NULL, 1);
+	preempt_enable();
+
+	profile_started = 0;
+
+	profile_finish_time = ktime_get();
+	profile_time = ktime_to_us(ktime_sub(profile_finish_time,
+						profile_start_time));
+
+	show_result();
+}
+
+/*********************************************************************
+ *                          Sysfs interface                          *
+ *********************************************************************/
+static ssize_t show_sysfs_result(struct kobject *kobj,
+				     struct kobj_attribute *attr,
+				     char *buf)
+{
+	int ret = 0;
+	int i, cpu, idle_ip, bit;
+	struct cpuidle_profile_info *info;
+	int state_count;
+
+	if (profile_started) {
+		ret += snprintf(buf + ret, PAGE_SIZE - ret,
+				"CPUIDLE profile is ongoing\n");
+		return ret;
+	}
+
+	if (profile_time == 0) {
+		ret += snprintf(buf + ret, PAGE_SIZE - ret,
+				"CPUIDLE profiler has not started yet\n");
+		return ret;
+	}
+
+	ret += snprintf(buf + ret, PAGE_SIZE - ret,
+		"#############################################################\n");
+	ret += snprintf(buf + ret, PAGE_SIZE - ret,
+		"Profiling Time : %lluus\n", profile_time);
+
+	ret += snprintf(buf + ret, PAGE_SIZE - ret,
+		"\n");
+
+	ret += snprintf(buf + ret, PAGE_SIZE - ret,
+		"[total idle ratio]\n");
+	ret += snprintf(buf + ret, PAGE_SIZE - ret,
+		"#cpu      #time    #ratio\n");
+	for_each_possible_cpu(cpu)
+		ret += snprintf(buf + ret, PAGE_SIZE - ret,
+			"cpu%d %10lluus   %3u%%\n",
+			cpu, sum_idle_time(cpu), total_idle_ratio(cpu));
+
+	ret += snprintf(buf + ret, PAGE_SIZE - ret,
+		"\n");
+
+	/*
+	 * All profile_info has same state_count. As a representative,
+	 * cpu0's is used.
+	 */
+	state_count = per_cpu(profile_info, 0).state_count;
+
+	for (i = 0; i < state_count; i++) {
+		ret += snprintf(buf + ret, PAGE_SIZE - ret,
+			"[state%d]\n", i);
+		ret += snprintf(buf + ret, PAGE_SIZE - ret,
+			"#cpu   #entry   #early      #time    #ratio\n");
+		for_each_possible_cpu(cpu) {
+			info = &per_cpu(profile_info, cpu);
+			ret += snprintf(buf + ret, PAGE_SIZE - ret,
+				"cpu%d   %5u   %5u   %10lluus   %3u%%\n",
+				cpu,
+				info->usage[i].entry_count,
+				info->usage[i].early_wakeup_count,
+				info->usage[i].time,
+				calculate_percent(info->usage[i].time));
+		}
+
+		ret += snprintf(buf + ret, PAGE_SIZE - ret,
+				"\n");
+	}
+
+	ret += snprintf(buf + ret, PAGE_SIZE - ret,
+		"[CPD] - Cluster Power Down\n");
+	ret += snprintf(buf + ret, PAGE_SIZE - ret,
+		"#cluster     #entry   #early      #time     #ratio\n");
+	for_each_cluster(i) {
+		ret += snprintf(buf + ret, PAGE_SIZE - ret,
+			"cl_%s   %5u   %5u   %10lluus    %3u%%\n",
+			i == to_cluster(cpu) ? "boot   " : "nonboot",
+			cpd_info[i].usage->entry_count,
+			cpd_info[i].usage->early_wakeup_count,
+			cpd_info[i].usage->time,
+			calculate_percent(cpd_info[i].usage->time));
+	}
+
+	ret += snprintf(buf + ret, PAGE_SIZE - ret,
+		"\n");
+
+	ret += snprintf(buf + ret, PAGE_SIZE - ret,
+		"[LPM] - Low Power Mode\n");
+	ret += snprintf(buf + ret, PAGE_SIZE - ret,
+		"#mode        #entry   #early      #time     #ratio\n");
+	for_each_syspower_mode(i) {
+		ret += snprintf(buf + ret, PAGE_SIZE - ret,
+			"%-9s    %5u   %5u   %10lluus    %3u%%\n",
+			get_sys_powerdown_str(i),
+			lpm_info.usage[i].entry_count,
+			lpm_info.usage[i].early_wakeup_count,
+			lpm_info.usage[i].time,
+			calculate_percent(lpm_info.usage[i].time));
+	}
+
+	ret += snprintf(buf + ret, PAGE_SIZE - ret,
+		"\n");
+
+	ret += snprintf(buf + ret, PAGE_SIZE - ret,
+		"[LPM blockers]\n");
+	for_each_syspower_mode(i) {
+		for_each_idle_ip(idle_ip) {
+			for (bit = 0; bit < IDLE_IP_REG_SIZE; bit++) {
+				if (idle_ip_pending[i][idle_ip][bit])
+					ret += snprintf(buf + ret, PAGE_SIZE -ret,
+						"%s block by IDLE_IP%d[%d](%s, count = %d)\n",
+						get_sys_powerdown_str(i),
+						idle_ip, bit, idle_ip_list[idle_ip][bit],
+						idle_ip_pending[i][idle_ip][bit]);
+			}
+		}
+	}
+
+	ret += snprintf(buf + ret, PAGE_SIZE - ret,
+		"#############################################################\n");
+
+	return ret;
+}
+
+static ssize_t show_cpuidle_profile(struct kobject *kobj,
+				     struct kobj_attribute *attr,
+				     char *buf)
+{
+	int ret = 0;
+
+	if (profile_started)
+		ret += snprintf(buf + ret, PAGE_SIZE - ret,
+				"CPUIDLE profile is ongoing\n");
+	else
+		ret = show_sysfs_result(kobj, attr, buf);
+
+
+	return ret;
+}
+
+static ssize_t store_cpuidle_profile(struct kobject *kobj,
+				      struct kobj_attribute *attr,
+				      const char *buf, size_t count)
+{
+	int input;
+
+	if (!sscanf(buf, "%1d", &input))
+		return -EINVAL;
+
+	if (!!input)
+		cpuidle_profile_main_start();
+	else
+		cpuidle_profile_main_finish();
+
+	return count;
+}
+
+static struct kobj_attribute cpuidle_profile_attr =
+	__ATTR(profile, 0644, show_cpuidle_profile, store_cpuidle_profile);
+
+static struct attribute *cpuidle_profile_attrs[] = {
+	&cpuidle_profile_attr.attr,
+	NULL,
+};
+
+static const struct attribute_group cpuidle_profile_group = {
+	.attrs = cpuidle_profile_attrs,
+};
+
+
+/*********************************************************************
+ *                   Initialize cpuidle profiler                     *
+ *********************************************************************/
+static void __init cpuidle_profile_info_init(struct cpuidle_profile_info *info,
+						int state_count)
+{
+	int size = sizeof(struct cpuidle_profile_state_usage) * state_count;
+
+	info->state_count = state_count;
+	info->usage = kmalloc(size, GFP_KERNEL);
+	if (!info->usage) {
+		pr_err("%s:%d: Memory allocation failed\n", __func__, __LINE__);
+		return;
+	}
+}
+
+void __init cpuidle_profile_register(struct cpuidle_driver *drv)
+{
+	int idle_state_count = drv->state_count;
+	int i;
+
+	/* Initialize each cpuidle state information */
+	for_each_possible_cpu(i)
+		cpuidle_profile_info_init(&per_cpu(profile_info, i),
+						idle_state_count);
+
+	/* Initiailize CPD(Cluster Power Down) information */
+	for_each_cluster(i)
+		cpuidle_profile_info_init(&cpd_info[i], 1);
+
+	/* Initiailize LPM(Low Power Mode) information */
+	cpuidle_profile_info_init(&lpm_info, NUM_SYS_POWERDOWN);
+}
+
+static int __init cpuidle_profile_init(void)
+{
+	struct class *class;
+	struct device *dev;
+
+	class = class_create(THIS_MODULE, "cpuidle");
+	dev = device_create(class, NULL, 0, NULL, "cpuidle_profiler");
+
+	if (sysfs_create_group(&dev->kobj, &cpuidle_profile_group)) {
+		pr_err("CPUIDLE Profiler : error to create sysfs\n");
+		return -EINVAL;
+	}
+
+	exynos_get_idle_ip_list(idle_ip_list);
+
+	return 0;
+}
+late_initcall(cpuidle_profile_init);

drivers/cpuidle/driver.c

@@ -0,0 +1,384 @@
+/*
+ * driver.c - driver support
+ *
+ * (C) 2006-2007 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
+ *               Shaohua Li <shaohua.li@intel.com>
+ *               Adam Belay <abelay@novell.com>
+ *
+ * This code is licenced under the GPL.
+ */
+
+#include <linux/mutex.h>
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <linux/cpuidle.h>
+#include <linux/cpumask.h>
+#include <linux/clockchips.h>
+
+#include "cpuidle.h"
+
+DEFINE_SPINLOCK(cpuidle_driver_lock);
+
+#ifdef CONFIG_CPU_IDLE_MULTIPLE_DRIVERS
+
+static DEFINE_PER_CPU(struct cpuidle_driver *, cpuidle_drivers);
+
+/**
+ * __cpuidle_get_cpu_driver - return the cpuidle driver tied to a CPU.
+ * @cpu: the CPU handled by the driver
+ *
+ * Returns a pointer to struct cpuidle_driver or NULL if no driver has been
+ * registered for @cpu.
+ */
+static struct cpuidle_driver *__cpuidle_get_cpu_driver(int cpu)
+{
+	return per_cpu(cpuidle_drivers, cpu);
+}
+
+/**
+ * __cpuidle_unset_driver - unset per CPU driver variables.
+ * @drv: a valid pointer to a struct cpuidle_driver
+ *
+ * For each CPU in the driver's CPU mask, unset the registered driver per CPU
+ * variable. If @drv is different from the registered driver, the corresponding
+ * variable is not cleared.
+ */
+static inline void __cpuidle_unset_driver(struct cpuidle_driver *drv)
+{
+	int cpu;
+
+	for_each_cpu(cpu, drv->cpumask) {
+
+		if (drv != __cpuidle_get_cpu_driver(cpu))
+			continue;
+
+		per_cpu(cpuidle_drivers, cpu) = NULL;
+	}
+}
+
+/**
+ * __cpuidle_set_driver - set per CPU driver variables for the given driver.
+ * @drv: a valid pointer to a struct cpuidle_driver
+ *
+ * For each CPU in the driver's cpumask, unset the registered driver per CPU
+ * to @drv.
+ *
+ * Returns 0 on success, -EBUSY if the CPUs have driver(s) already.
+ */
+static inline int __cpuidle_set_driver(struct cpuidle_driver *drv)
+{
+	int cpu;
+
+	for_each_cpu(cpu, drv->cpumask) {
+
+		if (__cpuidle_get_cpu_driver(cpu)) {
+			__cpuidle_unset_driver(drv);
+			return -EBUSY;
+		}
+
+		per_cpu(cpuidle_drivers, cpu) = drv;
+	}
+
+	return 0;
+}
+
+#else
+
+static struct cpuidle_driver *cpuidle_curr_driver;
+
+/**
+ * __cpuidle_get_cpu_driver - return the global cpuidle driver pointer.
+ * @cpu: ignored without the multiple driver support
+ *
+ * Return a pointer to a struct cpuidle_driver object or NULL if no driver was
+ * previously registered.
+ */
+static inline struct cpuidle_driver *__cpuidle_get_cpu_driver(int cpu)
+{
+	return cpuidle_curr_driver;
+}
+
+/**
+ * __cpuidle_set_driver - assign the global cpuidle driver variable.
+ * @drv: pointer to a struct cpuidle_driver object
+ *
+ * Returns 0 on success, -EBUSY if the driver is already registered.
+ */
+static inline int __cpuidle_set_driver(struct cpuidle_driver *drv)
+{
+	if (cpuidle_curr_driver)
+		return -EBUSY;
+
+	cpuidle_curr_driver = drv;
+
+	return 0;
+}
+
+/**
+ * __cpuidle_unset_driver - unset the global cpuidle driver variable.
+ * @drv: a pointer to a struct cpuidle_driver
+ *
+ * Reset the global cpuidle variable to NULL.  If @drv does not match the
+ * registered driver, do nothing.
+ */
+static inline void __cpuidle_unset_driver(struct cpuidle_driver *drv)
+{
+	if (drv == cpuidle_curr_driver)
+		cpuidle_curr_driver = NULL;
+}
+
+#endif
+
+/**
+ * cpuidle_setup_broadcast_timer - enable/disable the broadcast timer
+ * @arg: a void pointer used to match the SMP cross call API
+ *
+ * @arg is used as a value of type 'long' with one of the two values:
+ * - CLOCK_EVT_NOTIFY_BROADCAST_ON
+ * - CLOCK_EVT_NOTIFY_BROADCAST_OFF
+ *
+ * Set the broadcast timer notification for the current CPU.  This function
+ * is executed per CPU by an SMP cross call.  It not supposed to be called
+ * directly.
+ */
+static void cpuidle_setup_broadcast_timer(void *arg)
+{
+	int cpu = smp_processor_id();
+	clockevents_notify((long)(arg), &cpu);
+}
+
+/**
+ * __cpuidle_driver_init - initialize the driver's internal data
+ * @drv: a valid pointer to a struct cpuidle_driver
+ */
+static void __cpuidle_driver_init(struct cpuidle_driver *drv)
+{
+	int i;
+
+	drv->refcnt = 0;
+
+	/*
+	 * Use all possible CPUs as the default, because if the kernel boots
+	 * with some CPUs offline and then we online one of them, the CPU
+	 * notifier has to know which driver to assign.
+	 */
+	if (!drv->cpumask)
+		drv->cpumask = (struct cpumask *)cpu_possible_mask;
+
+	/*
+	 * Look for the timer stop flag in the different states, so that we know
+	 * if the broadcast timer has to be set up.  The loop is in the reverse
+	 * order, because usually one of the deeper states have this flag set.
+	 */
+	for (i = drv->state_count - 1; i >= 0 ; i--) {
+		if (drv->states[i].flags & CPUIDLE_FLAG_TIMER_STOP) {
+			drv->bctimer = 1;
+			break;
+		}
+	}
+}
+
+#ifdef CONFIG_ARCH_HAS_CPU_RELAX
+static int poll_idle(struct cpuidle_device *dev,
+		struct cpuidle_driver *drv, int index)
+{
+	local_irq_enable();
+	if (!current_set_polling_and_test()) {
+		while (!need_resched())
+			cpu_relax();
+	}
+	current_clr_polling();
+
+	return index;
+}
+
+static void poll_idle_init(struct cpuidle_driver *drv)
+{
+	struct cpuidle_state *state = &drv->states[0];
+
+	snprintf(state->name, CPUIDLE_NAME_LEN, "POLL");
+	snprintf(state->desc, CPUIDLE_DESC_LEN, "CPUIDLE CORE POLL IDLE");
+	state->exit_latency = 0;
+	state->target_residency = 0;
+	state->power_usage = -1;
+	state->flags = CPUIDLE_FLAG_TIME_VALID;
+	state->enter = poll_idle;
+	state->disabled = false;
+}
+#else
+static void poll_idle_init(struct cpuidle_driver *drv) {}
+#endif /* !CONFIG_ARCH_HAS_CPU_RELAX */
+
+/**
+ * __cpuidle_register_driver: register the driver
+ * @drv: a valid pointer to a struct cpuidle_driver
+ *
+ * Do some sanity checks, initialize the driver, assign the driver to the
+ * global cpuidle driver variable(s) and set up the broadcast timer if the
+ * cpuidle driver has some states that shut down the local timer.
+ *
+ * Returns 0 on success, a negative error code otherwise:
+ *  * -EINVAL if the driver pointer is NULL or no idle states are available
+ *  * -ENODEV if the cpuidle framework is disabled
+ *  * -EBUSY if the driver is already assigned to the global variable(s)
+ */
+static int __cpuidle_register_driver(struct cpuidle_driver *drv)
+{
+	int ret;
+
+	if (!drv || !drv->state_count)
+		return -EINVAL;
+
+	if (cpuidle_disabled())
+		return -ENODEV;
+
+	__cpuidle_driver_init(drv);
+
+	ret = __cpuidle_set_driver(drv);
+	if (ret)
+		return ret;
+
+	if (drv->bctimer)
+		on_each_cpu_mask(drv->cpumask, cpuidle_setup_broadcast_timer,
+				 (void *)CLOCK_EVT_NOTIFY_BROADCAST_ON, 1);
+
+	poll_idle_init(drv);
+
+	return 0;
+}
+
+/**
+ * __cpuidle_unregister_driver - unregister the driver
+ * @drv: a valid pointer to a struct cpuidle_driver
+ *
+ * Check if the driver is no longer in use, reset the global cpuidle driver
+ * variable(s) and disable the timer broadcast notification mechanism if it was
+ * in use.
+ *
+ */
+static void __cpuidle_unregister_driver(struct cpuidle_driver *drv)
+{
+	if (WARN_ON(drv->refcnt > 0))
+		return;
+
+	if (drv->bctimer) {
+		drv->bctimer = 0;
+		on_each_cpu_mask(drv->cpumask, cpuidle_setup_broadcast_timer,
+				 (void *)CLOCK_EVT_NOTIFY_BROADCAST_OFF, 1);
+	}
+
+	__cpuidle_unset_driver(drv);
+}
+
+/**
+ * cpuidle_register_driver - registers a driver
+ * @drv: a pointer to a valid struct cpuidle_driver
+ *
+ * Register the driver under a lock to prevent concurrent attempts to
+ * [un]register the driver from occuring at the same time.
+ *
+ * Returns 0 on success, a negative error code (returned by
+ * __cpuidle_register_driver()) otherwise.
+ */
+int cpuidle_register_driver(struct cpuidle_driver *drv)
+{
+	int ret;
+
+	spin_lock(&cpuidle_driver_lock);
+	ret = __cpuidle_register_driver(drv);
+	spin_unlock(&cpuidle_driver_lock);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(cpuidle_register_driver);
+
+/**
+ * cpuidle_unregister_driver - unregisters a driver
+ * @drv: a pointer to a valid struct cpuidle_driver
+ *
+ * Unregisters the cpuidle driver under a lock to prevent concurrent attempts
+ * to [un]register the driver from occuring at the same time.  @drv has to
+ * match the currently registered driver.
+ */
+void cpuidle_unregister_driver(struct cpuidle_driver *drv)
+{
+	spin_lock(&cpuidle_driver_lock);
+	__cpuidle_unregister_driver(drv);
+	spin_unlock(&cpuidle_driver_lock);
+}
+EXPORT_SYMBOL_GPL(cpuidle_unregister_driver);
+
+/**
+ * cpuidle_get_driver - return the driver tied to the current CPU.
+ *
+ * Returns a struct cpuidle_driver pointer, or NULL if no driver is registered.
+ */
+struct cpuidle_driver *cpuidle_get_driver(void)
+{
+	struct cpuidle_driver *drv;
+	int cpu;
+
+	cpu = get_cpu();
+	drv = __cpuidle_get_cpu_driver(cpu);
+	put_cpu();
+
+	return drv;
+}
+EXPORT_SYMBOL_GPL(cpuidle_get_driver);
+
+/**
+ * cpuidle_get_cpu_driver - return the driver registered for a CPU.
+ * @dev: a valid pointer to a struct cpuidle_device
+ *
+ * Returns a struct cpuidle_driver pointer, or NULL if no driver is registered
+ * for the CPU associated with @dev.
+ */
+struct cpuidle_driver *cpuidle_get_cpu_driver(struct cpuidle_device *dev)
+{
+	if (!dev)
+		return NULL;
+
+	return __cpuidle_get_cpu_driver(dev->cpu);
+}
+EXPORT_SYMBOL_GPL(cpuidle_get_cpu_driver);
+
+/**
+ * cpuidle_driver_ref - get a reference to the driver.
+ *
+ * Increment the reference counter of the cpuidle driver associated with
+ * the current CPU.
+ *
+ * Returns a pointer to the driver, or NULL if the current CPU has no driver.
+ */
+struct cpuidle_driver *cpuidle_driver_ref(void)
+{
+	struct cpuidle_driver *drv;
+
+	spin_lock(&cpuidle_driver_lock);
+
+	drv = cpuidle_get_driver();
+	if (drv)
+		drv->refcnt++;
+
+	spin_unlock(&cpuidle_driver_lock);
+	return drv;
+}
+
+/**
+ * cpuidle_driver_unref - puts down the refcount for the driver
+ *
+ * Decrement the reference counter of the cpuidle driver associated with
+ * the current CPU.
+ */
+void cpuidle_driver_unref(void)
+{
+	struct cpuidle_driver *drv;
+
+	spin_lock(&cpuidle_driver_lock);
+
+	drv = cpuidle_get_driver();
+	if (drv && !WARN_ON(drv->refcnt <= 0))
+		drv->refcnt--;
+
+	spin_unlock(&cpuidle_driver_lock);
+}

drivers/cpuidle/dt_idle_states.c

@@ -0,0 +1,216 @@
+/*
+ * DT idle states parsing code.
+ *
+ * Copyright (C) 2014 ARM Ltd.
+ * Author: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#define pr_fmt(fmt) "DT idle-states: " fmt
+
+#include <linux/cpuidle.h>
+#include <linux/cpumask.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+
+#include "dt_idle_states.h"
+
+static int init_state_node(struct cpuidle_state *idle_state,
+			   const struct of_device_id *matches,
+			   struct device_node *state_node)
+{
+	int err;
+	const struct of_device_id *match_id;
+
+	match_id = of_match_node(matches, state_node);
+	if (!match_id)
+		return -ENODEV;
+	/*
+	 * CPUidle drivers are expected to initialize the const void *data
+	 * pointer of the passed in struct of_device_id array to the idle
+	 * state enter function.
+	 */
+	idle_state->enter = match_id->data;
+
+	if (!of_device_is_available(state_node))
+		idle_state->disabled = 1;
+
+	err = of_property_read_u32(state_node, "wakeup-latency-us",
+				   &idle_state->exit_latency);
+	if (err) {
+		u32 entry_latency, exit_latency;
+
+		err = of_property_read_u32(state_node, "entry-latency-us",
+					   &entry_latency);
+		if (err) {
+			pr_debug(" * %s missing entry-latency-us property\n",
+				 state_node->full_name);
+			return -EINVAL;
+		}
+
+		err = of_property_read_u32(state_node, "exit-latency-us",
+					   &exit_latency);
+		if (err) {
+			pr_debug(" * %s missing exit-latency-us property\n",
+				 state_node->full_name);
+			return -EINVAL;
+		}
+		/*
+		 * If wakeup-latency-us is missing, default to entry+exit
+		 * latencies as defined in idle states bindings
+		 */
+		idle_state->exit_latency = entry_latency + exit_latency;
+	}
+
+	err = of_property_read_u32(state_node, "min-residency-us",
+				   &idle_state->target_residency);
+	if (err) {
+		pr_debug(" * %s missing min-residency-us property\n",
+			     state_node->full_name);
+		return -EINVAL;
+	}
+
+	idle_state->flags = CPUIDLE_FLAG_TIME_VALID;
+	if (of_property_read_bool(state_node, "local-timer-stop"))
+		idle_state->flags |= CPUIDLE_FLAG_TIMER_STOP;
+	/*
+	 * TODO:
+	 *	replace with kstrdup and pointer assignment when name
+	 *	and desc become string pointers
+	 */
+	strncpy(idle_state->name, state_node->name, CPUIDLE_NAME_LEN - 1);
+	strncpy(idle_state->desc, state_node->name, CPUIDLE_DESC_LEN - 1);
+	return 0;
+}
+
+/*
+ * Check that the idle state is uniform across all CPUs in the CPUidle driver
+ * cpumask
+ */
+static bool idle_state_valid(struct device_node *state_node, unsigned int idx,
+			     const cpumask_t *cpumask)
+{
+	int cpu;
+	struct device_node *cpu_node, *curr_state_node;
+	bool valid = true;
+
+	/*
+	 * Compare idle state phandles for index idx on all CPUs in the
+	 * CPUidle driver cpumask. Start from next logical cpu following
+	 * cpumask_first(cpumask) since that's the CPU state_node was
+	 * retrieved from. If a mismatch is found bail out straight
+	 * away since we certainly hit a firmware misconfiguration.
+	 */
+	for (cpu = cpumask_next(cpumask_first(cpumask), cpumask);
+	     cpu < nr_cpu_ids; cpu = cpumask_next(cpu, cpumask)) {
+		cpu_node = of_cpu_device_node_get(cpu);
+		curr_state_node = of_parse_phandle(cpu_node, "cpu-idle-states",
+						   idx);
+		if (state_node != curr_state_node)
+			valid = false;
+
+		of_node_put(curr_state_node);
+		of_node_put(cpu_node);
+		if (!valid)
+			break;
+	}
+
+	return valid;
+}
+
+/**
+ * dt_init_idle_driver() - Parse the DT idle states and initialize the
+ *			   idle driver states array
+ * @drv:	  Pointer to CPU idle driver to be initialized
+ * @matches:	  Array of of_device_id match structures to search in for
+ *		  compatible idle state nodes. The data pointer for each valid
+ *		  struct of_device_id entry in the matches array must point to
+ *		  a function with the following signature, that corresponds to
+ *		  the CPUidle state enter function signature:
+ *
+ *		  int (*)(struct cpuidle_device *dev,
+ *			  struct cpuidle_driver *drv,
+ *			  int index);
+ *
+ * @start_idx:    First idle state index to be initialized
+ *
+ * If DT idle states are detected and are valid the state count and states
+ * array entries in the cpuidle driver are initialized accordingly starting
+ * from index start_idx.
+ *
+ * Return: number of valid DT idle states parsed, <0 on failure
+ */
+int dt_init_idle_driver(struct cpuidle_driver *drv,
+			const struct of_device_id *matches,
+			unsigned int start_idx)
+{
+	struct cpuidle_state *idle_state;
+	struct device_node *state_node, *cpu_node;
+	int i, err = 0;
+	const cpumask_t *cpumask;
+	unsigned int state_idx = start_idx;
+
+	if (state_idx >= CPUIDLE_STATE_MAX)
+		return -EINVAL;
+	/*
+	 * We get the idle states for the first logical cpu in the
+	 * driver mask (or cpu_possible_mask if the driver cpumask is not set)
+	 * and we check through idle_state_valid() if they are uniform
+	 * across CPUs, otherwise we hit a firmware misconfiguration.
+	 */
+	cpumask = drv->cpumask ? : cpu_possible_mask;
+	cpu_node = of_cpu_device_node_get(cpumask_first(cpumask));
+
+	for (i = 0; ; i++) {
+		state_node = of_parse_phandle(cpu_node, "cpu-idle-states", i);
+		if (!state_node)
+			break;
+
+		if (!idle_state_valid(state_node, i, cpumask)) {
+			pr_warn("%s idle state not valid, bailing out\n",
+				state_node->full_name);
+			err = -EINVAL;
+			break;
+		}
+
+		if (state_idx == CPUIDLE_STATE_MAX) {
+			pr_warn("State index reached static CPU idle driver states array size\n");
+			break;
+		}
+
+		idle_state = &drv->states[state_idx++];
+		err = init_state_node(idle_state, matches, state_node);
+		if (err) {
+			pr_err("Parsing idle state node %s failed with err %d\n",
+			       state_node->full_name, err);
+			err = -EINVAL;
+			break;
+		}
+		of_node_put(state_node);
+	}
+
+	of_node_put(state_node);
+	of_node_put(cpu_node);
+	if (err)
+		return err;
+	/*
+	 * Update the driver state count only if some valid DT idle states
+	 * were detected
+	 */
+	if (i)
+		drv->state_count = state_idx;
+
+	/*
+	 * Return the number of present and valid DT idle states, which can
+	 * also be 0 on platforms with missing DT idle states or legacy DT
+	 * configuration predating the DT idle states bindings.
+	 */
+	return i;
+}
+EXPORT_SYMBOL_GPL(dt_init_idle_driver);

drivers/cpuidle/dt_idle_states.h

@@ -0,0 +1,7 @@
+#ifndef __DT_IDLE_STATES
+#define __DT_IDLE_STATES
+
+int dt_init_idle_driver(struct cpuidle_driver *drv,
+			const struct of_device_id *matches,
+			unsigned int start_idx);
+#endif

drivers/cpuidle/governor.c

@@ -0,0 +1,98 @@
+/*
+ * governor.c - governor support
+ *
+ * (C) 2006-2007 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
+ *               Shaohua Li <shaohua.li@intel.com>
+ *               Adam Belay <abelay@novell.com>
+ *
+ * This code is licenced under the GPL.
+ */
+
+#include <linux/mutex.h>
+#include <linux/module.h>
+#include <linux/cpuidle.h>
+
+#include "cpuidle.h"
+
+LIST_HEAD(cpuidle_governors);
+struct cpuidle_governor *cpuidle_curr_governor;
+
+/**
+ * __cpuidle_find_governor - finds a governor of the specified name
+ * @str: the name
+ *
+ * Must be called with cpuidle_lock acquired.
+ */
+static struct cpuidle_governor * __cpuidle_find_governor(const char *str)
+{
+	struct cpuidle_governor *gov;
+
+	list_for_each_entry(gov, &cpuidle_governors, governor_list)
+		if (!strncasecmp(str, gov->name, CPUIDLE_NAME_LEN))
+			return gov;
+
+	return NULL;
+}
+
+/**
+ * cpuidle_switch_governor - changes the governor
+ * @gov: the new target governor
+ *
+ * NOTE: "gov" can be NULL to specify disabled
+ * Must be called with cpuidle_lock acquired.
+ */
+int cpuidle_switch_governor(struct cpuidle_governor *gov)
+{
+	struct cpuidle_device *dev;
+
+	if (gov == cpuidle_curr_governor)
+		return 0;
+
+	cpuidle_uninstall_idle_handler();
+
+	if (cpuidle_curr_governor) {
+		list_for_each_entry(dev, &cpuidle_detected_devices, device_list)
+			cpuidle_disable_device(dev);
+		module_put(cpuidle_curr_governor->owner);
+	}
+
+	cpuidle_curr_governor = gov;
+
+	if (gov) {
+		if (!try_module_get(cpuidle_curr_governor->owner))
+			return -EINVAL;
+		list_for_each_entry(dev, &cpuidle_detected_devices, device_list)
+			cpuidle_enable_device(dev);
+		cpuidle_install_idle_handler();
+		printk(KERN_INFO "cpuidle: using governor %s\n", gov->name);
+	}
+
+	return 0;
+}
+
+/**
+ * cpuidle_register_governor - registers a governor
+ * @gov: the governor
+ */
+int cpuidle_register_governor(struct cpuidle_governor *gov)
+{
+	int ret = -EEXIST;
+
+	if (!gov || !gov->select)
+		return -EINVAL;
+
+	if (cpuidle_disabled())
+		return -ENODEV;
+
+	mutex_lock(&cpuidle_lock);
+	if (__cpuidle_find_governor(gov->name) == NULL) {
+		ret = 0;
+		list_add_tail(&gov->governor_list, &cpuidle_governors);
+		if (!cpuidle_curr_governor ||
+		    cpuidle_curr_governor->rating < gov->rating)
+			cpuidle_switch_governor(gov);
+	}
+	mutex_unlock(&cpuidle_lock);
+
+	return ret;
+}

drivers/cpuidle/governors/Makefile

@@ -0,0 +1,6 @@
+#
+# Makefile for cpuidle governors.
+#
+
+obj-$(CONFIG_CPU_IDLE_GOV_LADDER) += ladder.o
+obj-$(CONFIG_CPU_IDLE_GOV_MENU) += menu.o

drivers/cpuidle/governors/ladder.c

@@ -0,0 +1,195 @@
+/*
+ * ladder.c - the residency ladder algorithm
+ *
+ *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
+ *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
+ *  Copyright (C) 2004, 2005 Dominik Brodowski <linux@brodo.de>
+ *
+ * (C) 2006-2007 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
+ *               Shaohua Li <shaohua.li@intel.com>
+ *               Adam Belay <abelay@novell.com>
+ *
+ * This code is licenced under the GPL.
+ */
+
+#include <linux/kernel.h>
+#include <linux/cpuidle.h>
+#include <linux/pm_qos.h>
+#include <linux/module.h>
+#include <linux/jiffies.h>
+
+#include <asm/io.h>
+#include <asm/uaccess.h>
+
+#define PROMOTION_COUNT 4
+#define DEMOTION_COUNT 1
+
+struct ladder_device_state {
+	struct {
+		u32 promotion_count;
+		u32 demotion_count;
+		u32 promotion_time;
+		u32 demotion_time;
+	} threshold;
+	struct {
+		int promotion_count;
+		int demotion_count;
+	} stats;
+};
+
+struct ladder_device {
+	struct ladder_device_state states[CPUIDLE_STATE_MAX];
+	int last_state_idx;
+};
+
+static DEFINE_PER_CPU(struct ladder_device, ladder_devices);
+
+/**
+ * ladder_do_selection - prepares private data for a state change
+ * @ldev: the ladder device
+ * @old_idx: the current state index
+ * @new_idx: the new target state index
+ */
+static inline void ladder_do_selection(struct ladder_device *ldev,
+				       int old_idx, int new_idx)
+{
+	ldev->states[old_idx].stats.promotion_count = 0;
+	ldev->states[old_idx].stats.demotion_count = 0;
+	ldev->last_state_idx = new_idx;
+}
+
+/**
+ * ladder_select_state - selects the next state to enter
+ * @drv: cpuidle driver
+ * @dev: the CPU
+ */
+static int ladder_select_state(struct cpuidle_driver *drv,
+				struct cpuidle_device *dev)
+{
+	struct ladder_device *ldev = this_cpu_ptr(&ladder_devices);
+	struct ladder_device_state *last_state;
+	int last_residency, last_idx = ldev->last_state_idx;
+	int latency_req = pm_qos_request(PM_QOS_CPU_DMA_LATENCY);
+
+	/* Special case when user has set very strict latency requirement */
+	if (unlikely(latency_req == 0)) {
+		ladder_do_selection(ldev, last_idx, 0);
+		return 0;
+	}
+
+	last_state = &ldev->states[last_idx];
+
+	if (drv->states[last_idx].flags & CPUIDLE_FLAG_TIME_VALID) {
+		last_residency = cpuidle_get_last_residency(dev) - \
+					 drv->states[last_idx].exit_latency;
+	}
+	else
+		last_residency = last_state->threshold.promotion_time + 1;
+
+	/* consider promotion */
+	if (last_idx < drv->state_count - 1 &&
+	    !drv->states[last_idx + 1].disabled &&
+	    !dev->states_usage[last_idx + 1].disable &&
+	    last_residency > last_state->threshold.promotion_time &&
+	    drv->states[last_idx + 1].exit_latency <= latency_req) {
+		last_state->stats.promotion_count++;
+		last_state->stats.demotion_count = 0;
+		if (last_state->stats.promotion_count >= last_state->threshold.promotion_count) {
+			ladder_do_selection(ldev, last_idx, last_idx + 1);
+			return last_idx + 1;
+		}
+	}
+
+	/* consider demotion */
+	if (last_idx > CPUIDLE_DRIVER_STATE_START &&
+	    (drv->states[last_idx].disabled ||
+	    dev->states_usage[last_idx].disable ||
+	    drv->states[last_idx].exit_latency > latency_req)) {
+		int i;
+
+		for (i = last_idx - 1; i > CPUIDLE_DRIVER_STATE_START; i--) {
+			if (drv->states[i].exit_latency <= latency_req)
+				break;
+		}
+		ladder_do_selection(ldev, last_idx, i);
+		return i;
+	}
+
+	if (last_idx > CPUIDLE_DRIVER_STATE_START &&
+	    last_residency < last_state->threshold.demotion_time) {
+		last_state->stats.demotion_count++;
+		last_state->stats.promotion_count = 0;
+		if (last_state->stats.demotion_count >= last_state->threshold.demotion_count) {
+			ladder_do_selection(ldev, last_idx, last_idx - 1);
+			return last_idx - 1;
+		}
+	}
+
+	/* otherwise remain at the current state */
+	return last_idx;
+}
+
+/**
+ * ladder_enable_device - setup for the governor
+ * @drv: cpuidle driver
+ * @dev: the CPU
+ */
+static int ladder_enable_device(struct cpuidle_driver *drv,
+				struct cpuidle_device *dev)
+{
+	int i;
+	struct ladder_device *ldev = &per_cpu(ladder_devices, dev->cpu);
+	struct ladder_device_state *lstate;
+	struct cpuidle_state *state;
+
+	ldev->last_state_idx = CPUIDLE_DRIVER_STATE_START;
+
+	for (i = CPUIDLE_DRIVER_STATE_START; i < drv->state_count; i++) {
+		state = &drv->states[i];
+		lstate = &ldev->states[i];
+
+		lstate->stats.promotion_count = 0;
+		lstate->stats.demotion_count = 0;
+
+		lstate->threshold.promotion_count = PROMOTION_COUNT;
+		lstate->threshold.demotion_count = DEMOTION_COUNT;
+
+		if (i < drv->state_count - 1)
+			lstate->threshold.promotion_time = state->exit_latency;
+		if (i > CPUIDLE_DRIVER_STATE_START)
+			lstate->threshold.demotion_time = state->exit_latency;
+	}
+
+	return 0;
+}
+
+/**
+ * ladder_reflect - update the correct last_state_idx
+ * @dev: the CPU
+ * @index: the index of actual state entered
+ */
+static void ladder_reflect(struct cpuidle_device *dev, int index)
+{
+	struct ladder_device *ldev = this_cpu_ptr(&ladder_devices);
+	if (index > 0)
+		ldev->last_state_idx = index;
+}
+
+static struct cpuidle_governor ladder_governor = {
+	.name =		"ladder",
+	.rating =	10,
+	.enable =	ladder_enable_device,
+	.select =	ladder_select_state,
+	.reflect =	ladder_reflect,
+	.owner =	THIS_MODULE,
+};
+
+/**
+ * init_ladder - initializes the governor
+ */
+static int __init init_ladder(void)
+{
+	return cpuidle_register_governor(&ladder_governor);
+}
+
+postcore_initcall(init_ladder);

drivers/cpuidle/governors/menu.c

@@ -0,0 +1,503 @@
+/*
+ * menu.c - the menu idle governor
+ *
+ * Copyright (C) 2006-2007 Adam Belay <abelay@novell.com>
+ * Copyright (C) 2009 Intel Corporation
+ * Author:
+ *        Arjan van de Ven <arjan@linux.intel.com>
+ *
+ * This code is licenced under the GPL version 2 as described
+ * in the COPYING file that acompanies the Linux Kernel.
+ */
+
+#include <linux/kernel.h>
+#include <linux/cpuidle.h>
+#include <linux/pm_qos.h>
+#include <linux/time.h>
+#include <linux/ktime.h>
+#include <linux/hrtimer.h>
+#include <linux/tick.h>
+#include <linux/sched.h>
+#include <linux/math64.h>
+#include <linux/module.h>
+
+/*
+ * Please note when changing the tuning values:
+ * If (MAX_INTERESTING-1) * RESOLUTION > UINT_MAX, the result of
+ * a scaling operation multiplication may overflow on 32 bit platforms.
+ * In that case, #define RESOLUTION as ULL to get 64 bit result:
+ * #define RESOLUTION 1024ULL
+ *
+ * The default values do not overflow.
+ */
+#define BUCKETS 12
+#define INTERVAL_SHIFT 3
+#define INTERVALS (1UL << INTERVAL_SHIFT)
+#define RESOLUTION 1024
+#define DECAY 8
+#define MAX_INTERESTING 50000
+
+
+/*
+ * Concepts and ideas behind the menu governor
+ *
+ * For the menu governor, there are 3 decision factors for picking a C
+ * state:
+ * 1) Energy break even point
+ * 2) Performance impact
+ * 3) Latency tolerance (from pmqos infrastructure)
+ * These these three factors are treated independently.
+ *
+ * Energy break even point
+ * -----------------------
+ * C state entry and exit have an energy cost, and a certain amount of time in
+ * the  C state is required to actually break even on this cost. CPUIDLE
+ * provides us this duration in the "target_residency" field. So all that we
+ * need is a good prediction of how long we'll be idle. Like the traditional
+ * menu governor, we start with the actual known "next timer event" time.
+ *
+ * Since there are other source of wakeups (interrupts for example) than
+ * the next timer event, this estimation is rather optimistic. To get a
+ * more realistic estimate, a correction factor is applied to the estimate,
+ * that is based on historic behavior. For example, if in the past the actual
+ * duration always was 50% of the next timer tick, the correction factor will
+ * be 0.5.
+ *
+ * menu uses a running average for this correction factor, however it uses a
+ * set of factors, not just a single factor. This stems from the realization
+ * that the ratio is dependent on the order of magnitude of the expected
+ * duration; if we expect 500 milliseconds of idle time the likelihood of
+ * getting an interrupt very early is much higher than if we expect 50 micro
+ * seconds of idle time. A second independent factor that has big impact on
+ * the actual factor is if there is (disk) IO outstanding or not.
+ * (as a special twist, we consider every sleep longer than 50 milliseconds
+ * as perfect; there are no power gains for sleeping longer than this)
+ *
+ * For these two reasons we keep an array of 12 independent factors, that gets
+ * indexed based on the magnitude of the expected duration as well as the
+ * "is IO outstanding" property.
+ *
+ * Repeatable-interval-detector
+ * ----------------------------
+ * There are some cases where "next timer" is a completely unusable predictor:
+ * Those cases where the interval is fixed, for example due to hardware
+ * interrupt mitigation, but also due to fixed transfer rate devices such as
+ * mice.
+ * For this, we use a different predictor: We track the duration of the last 8
+ * intervals and if the stand deviation of these 8 intervals is below a
+ * threshold value, we use the average of these intervals as prediction.
+ *
+ * Limiting Performance Impact
+ * ---------------------------
+ * C states, especially those with large exit latencies, can have a real
+ * noticeable impact on workloads, which is not acceptable for most sysadmins,
+ * and in addition, less performance has a power price of its own.
+ *
+ * As a general rule of thumb, menu assumes that the following heuristic
+ * holds:
+ *     The busier the system, the less impact of C states is acceptable
+ *
+ * This rule-of-thumb is implemented using a performance-multiplier:
+ * If the exit latency times the performance multiplier is longer than
+ * the predicted duration, the C state is not considered a candidate
+ * for selection due to a too high performance impact. So the higher
+ * this multiplier is, the longer we need to be idle to pick a deep C
+ * state, and thus the less likely a busy CPU will hit such a deep
+ * C state.
+ *
+ * Two factors are used in determing this multiplier:
+ * a value of 10 is added for each point of "per cpu load average" we have.
+ * a value of 5 points is added for each process that is waiting for
+ * IO on this CPU.
+ * (these values are experimentally determined)
+ *
+ * The load average factor gives a longer term (few seconds) input to the
+ * decision, while the iowait value gives a cpu local instantanious input.
+ * The iowait factor may look low, but realize that this is also already
+ * represented in the system load average.
+ *
+ */
+
+struct menu_device {
+	int		last_state_idx;
+	int             needs_update;
+
+	unsigned int	next_timer_us;
+	unsigned int	predicted_us;
+	unsigned int	bucket;
+	unsigned int	correction_factor[BUCKETS];
+	unsigned int	intervals[INTERVALS];
+	int		interval_ptr;
+};
+
+
+#define LOAD_INT(x) ((x) >> FSHIFT)
+#define LOAD_FRAC(x) LOAD_INT(((x) & (FIXED_1-1)) * 100)
+
+static inline int get_loadavg(unsigned long load)
+{
+	return LOAD_INT(load) * 10 + LOAD_FRAC(load) / 10;
+}
+
+static inline int which_bucket(unsigned int duration, unsigned long nr_iowaiters)
+{
+	int bucket = 0;
+
+	/*
+	 * We keep two groups of stats; one with no
+	 * IO pending, one without.
+	 * This allows us to calculate
+	 * E(duration)|iowait
+	 */
+	if (nr_iowaiters)
+		bucket = BUCKETS/2;
+
+	if (duration < 10)
+		return bucket;
+	if (duration < 100)
+		return bucket + 1;
+	if (duration < 1000)
+		return bucket + 2;
+	if (duration < 10000)
+		return bucket + 3;
+	if (duration < 100000)
+		return bucket + 4;
+	return bucket + 5;
+}
+
+/*
+ * Return a multiplier for the exit latency that is intended
+ * to take performance requirements into account.
+ * The more performance critical we estimate the system
+ * to be, the higher this multiplier, and thus the higher
+ * the barrier to go to an expensive C state.
+ */
+static inline int performance_multiplier(unsigned long nr_iowaiters, unsigned long load)
+{
+	int mult = 1;
+
+	/* for higher loadavg, we are more reluctant */
+
+	/*
+	 * this doesn't work as intended - it is almost always 0, but can
+	 * sometimes, depending on workload, spike very high into the hundreds
+	 * even when the average cpu load is under 10%.
+	 */
+	/* mult += 2 * get_loadavg(); */
+
+	/* for IO wait tasks (per cpu!) we add 5x each */
+	mult += 10 * nr_iowaiters;
+
+	return mult;
+}
+
+static DEFINE_PER_CPU(struct menu_device, menu_devices);
+
+static void menu_update(struct cpuidle_driver *drv, struct cpuidle_device *dev);
+
+/* This implements DIV_ROUND_CLOSEST but avoids 64 bit division */
+static u64 div_round64(u64 dividend, u32 divisor)
+{
+	return div_u64(dividend + (divisor / 2), divisor);
+}
+
+/*
+ * Try detecting repeating patterns by keeping track of the last 8
+ * intervals, and checking if the standard deviation of that set
+ * of points is below a threshold. If it is... then use the
+ * average of these 8 points as the estimated value.
+ */
+static void get_typical_interval(struct menu_device *data)
+{
+	int i, divisor;
+	unsigned int max, thresh;
+	uint64_t avg, stddev;
+
+	thresh = UINT_MAX; /* Discard outliers above this value */
+
+again:
+
+	/* First calculate the average of past intervals */
+	max = 0;
+	avg = 0;
+	divisor = 0;
+	for (i = 0; i < INTERVALS; i++) {
+		unsigned int value = data->intervals[i];
+		if (value <= thresh) {
+			avg += value;
+			divisor++;
+			if (value > max)
+				max = value;
+		}
+	}
+	if (divisor == INTERVALS)
+		avg >>= INTERVAL_SHIFT;
+	else
+		do_div(avg, divisor);
+
+	/* Then try to determine standard deviation */
+	stddev = 0;
+	for (i = 0; i < INTERVALS; i++) {
+		unsigned int value = data->intervals[i];
+		if (value <= thresh) {
+			int64_t diff = value - avg;
+			stddev += diff * diff;
+		}
+	}
+	if (divisor == INTERVALS)
+		stddev >>= INTERVAL_SHIFT;
+	else
+		do_div(stddev, divisor);
+
+	/*
+	 * The typical interval is obtained when standard deviation is small
+	 * or standard deviation is small compared to the average interval.
+	 *
+	 * int_sqrt() formal parameter type is unsigned long. When the
+	 * greatest difference to an outlier exceeds ~65 ms * sqrt(divisor)
+	 * the resulting squared standard deviation exceeds the input domain
+	 * of int_sqrt on platforms where unsigned long is 32 bits in size.
+	 * In such case reject the candidate average.
+	 *
+	 * Use this result only if there is no timer to wake us up sooner.
+	 */
+	if (likely(stddev <= ULONG_MAX)) {
+		stddev = int_sqrt(stddev);
+		if (((avg > stddev * 6) && (divisor * 4 >= INTERVALS * 3))
+							|| stddev <= 20) {
+			if (data->next_timer_us > avg)
+				data->predicted_us = avg;
+			return;
+		}
+	}
+
+	/*
+	 * If we have outliers to the upside in our distribution, discard
+	 * those by setting the threshold to exclude these outliers, then
+	 * calculate the average and standard deviation again. Once we get
+	 * down to the bottom 3/4 of our samples, stop excluding samples.
+	 *
+	 * This can deal with workloads that have long pauses interspersed
+	 * with sporadic activity with a bunch of short pauses.
+	 */
+	if ((divisor * 4) <= INTERVALS * 3)
+		return;
+
+	thresh = max - 1;
+	goto again;
+}
+
+/**
+ * menu_select - selects the next idle state to enter
+ * @drv: cpuidle driver containing state data
+ * @dev: the CPU
+ */
+static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev)
+{
+	struct menu_device *data = this_cpu_ptr(&menu_devices);
+	int latency_req = pm_qos_request(PM_QOS_CPU_DMA_LATENCY);
+	int i;
+	unsigned int interactivity_req;
+	unsigned long nr_iowaiters, cpu_load;
+
+	if (data->needs_update) {
+		menu_update(drv, dev);
+		data->needs_update = 0;
+	}
+
+	data->last_state_idx = CPUIDLE_DRIVER_STATE_START - 1;
+
+	/* Special case when user has set very strict latency requirement */
+	if (unlikely(latency_req == 0))
+		return 0;
+
+	/* determine the expected residency time, round up */
+	data->next_timer_us = ktime_to_us(tick_nohz_get_sleep_length());
+
+	get_iowait_load(&nr_iowaiters, &cpu_load);
+	data->bucket = which_bucket(data->next_timer_us, nr_iowaiters);
+
+	/*
+	 * Force the result of multiplication to be 64 bits even if both
+	 * operands are 32 bits.
+	 * Make sure to round up for half microseconds.
+	 */
+	if (drv->skip_correction)
+		data->predicted_us = data->next_timer_us;
+	else
+		data->predicted_us = div_round64((uint64_t)data->next_timer_us *
+				data->correction_factor[data->bucket],
+				RESOLUTION * DECAY);
+
+	get_typical_interval(data);
+
+	/*
+	 * Performance multiplier defines a minimum predicted idle
+	 * duration / latency ratio. Adjust the latency limit if
+	 * necessary.
+	 */
+	interactivity_req = data->predicted_us / performance_multiplier(nr_iowaiters, cpu_load);
+	if (latency_req > interactivity_req)
+		latency_req = interactivity_req;
+
+	/*
+	 * We want to default to C1 (hlt), not to busy polling
+	 * unless the timer is happening really really soon.
+	 */
+	if (data->next_timer_us > 5 &&
+	    !drv->states[CPUIDLE_DRIVER_STATE_START].disabled &&
+		dev->states_usage[CPUIDLE_DRIVER_STATE_START].disable == 0)
+		data->last_state_idx = CPUIDLE_DRIVER_STATE_START;
+
+	/*
+	 * Find the idle state with the lowest power while satisfying
+	 * our constraints.
+	 */
+	for (i = CPUIDLE_DRIVER_STATE_START; i < drv->state_count; i++) {
+		struct cpuidle_state *s = &drv->states[i];
+		struct cpuidle_state_usage *su = &dev->states_usage[i];
+
+		if (s->disabled || su->disable)
+			continue;
+		if (s->target_residency > data->predicted_us)
+			continue;
+		if (s->exit_latency > latency_req)
+			continue;
+
+		data->last_state_idx = i;
+	}
+
+	return data->last_state_idx;
+}
+
+/**
+ * menu_reflect - records that data structures need update
+ * @dev: the CPU
+ * @index: the index of actual entered state
+ *
+ * NOTE: it's important to be fast here because this operation will add to
+ *       the overall exit latency.
+ */
+static void menu_reflect(struct cpuidle_device *dev, int index)
+{
+	struct menu_device *data = this_cpu_ptr(&menu_devices);
+	data->last_state_idx = index;
+	if (index >= 0)
+		data->needs_update = 1;
+}
+
+/**
+ * menu_update - attempts to guess what happened after entry
+ * @drv: cpuidle driver containing state data
+ * @dev: the CPU
+ */
+static void menu_update(struct cpuidle_driver *drv, struct cpuidle_device *dev)
+{
+	struct menu_device *data = this_cpu_ptr(&menu_devices);
+	int last_idx = data->last_state_idx;
+	struct cpuidle_state *target = &drv->states[last_idx];
+	unsigned int measured_us;
+	unsigned int new_factor;
+
+	/*
+	 * Try to figure out how much time passed between entry to low
+	 * power state and occurrence of the wakeup event.
+	 *
+	 * If the entered idle state didn't support residency measurements,
+	 * we are basically lost in the dark how much time passed.
+	 * As a compromise, assume we slept for the whole expected time.
+	 *
+	 * Any measured amount of time will include the exit latency.
+	 * Since we are interested in when the wakeup begun, not when it
+	 * was completed, we must subtract the exit latency. However, if
+	 * the measured amount of time is less than the exit latency,
+	 * assume the state was never reached and the exit latency is 0.
+	 */
+	if (unlikely(!(target->flags & CPUIDLE_FLAG_TIME_VALID))) {
+		/* Use timer value as is */
+		measured_us = data->next_timer_us;
+
+	} else {
+		/* Use measured value */
+		measured_us = cpuidle_get_last_residency(dev);
+
+		/* Deduct exit latency */
+		if (measured_us > target->exit_latency)
+			measured_us -= target->exit_latency;
+
+		/* Make sure our coefficients do not exceed unity */
+		if (measured_us > data->next_timer_us)
+			measured_us = data->next_timer_us;
+	}
+
+	/* Update our correction ratio */
+	new_factor = data->correction_factor[data->bucket];
+	new_factor -= new_factor / DECAY;
+
+	if (data->next_timer_us > 0 && measured_us < MAX_INTERESTING)
+		new_factor += RESOLUTION * measured_us / data->next_timer_us;
+	else
+		/*
+		 * we were idle so long that we count it as a perfect
+		 * prediction
+		 */
+		new_factor += RESOLUTION;
+
+	/*
+	 * We don't want 0 as factor; we always want at least
+	 * a tiny bit of estimated time. Fortunately, due to rounding,
+	 * new_factor will stay nonzero regardless of measured_us values
+	 * and the compiler can eliminate this test as long as DECAY > 1.
+	 */
+	if (DECAY == 1 && unlikely(new_factor == 0))
+		new_factor = 1;
+
+	data->correction_factor[data->bucket] = new_factor;
+
+	/* update the repeating-pattern data */
+	data->intervals[data->interval_ptr++] = measured_us;
+	if (data->interval_ptr >= INTERVALS)
+		data->interval_ptr = 0;
+}
+
+/**
+ * menu_enable_device - scans a CPU's states and does setup
+ * @drv: cpuidle driver
+ * @dev: the CPU
+ */
+static int menu_enable_device(struct cpuidle_driver *drv,
+				struct cpuidle_device *dev)
+{
+	struct menu_device *data = &per_cpu(menu_devices, dev->cpu);
+	int i;
+
+	memset(data, 0, sizeof(struct menu_device));
+
+	/*
+	 * if the correction factor is 0 (eg first time init or cpu hotplug
+	 * etc), we actually want to start out with a unity factor.
+	 */
+	for(i = 0; i < BUCKETS; i++)
+		data->correction_factor[i] = RESOLUTION * DECAY;
+
+	return 0;
+}
+
+static struct cpuidle_governor menu_governor = {
+	.name =		"menu",
+	.rating =	20,
+	.enable =	menu_enable_device,
+	.select =	menu_select,
+	.reflect =	menu_reflect,
+	.owner =	THIS_MODULE,
+};
+
+/**
+ * init_menu - initializes the governor
+ */
+static int __init init_menu(void)
+{
+	return cpuidle_register_governor(&menu_governor);
+}
+
+postcore_initcall(init_menu);

drivers/cpuidle/sysfs.c

@@ -0,0 +1,647 @@
+/*
+ * sysfs.c - sysfs support
+ *
+ * (C) 2006-2007 Shaohua Li <shaohua.li@intel.com>
+ *
+ * This code is licenced under the GPL.
+ */
+
+#include <linux/kernel.h>
+#include <linux/cpuidle.h>
+#include <linux/sysfs.h>
+#include <linux/slab.h>
+#include <linux/cpu.h>
+#include <linux/completion.h>
+#include <linux/capability.h>
+#include <linux/device.h>
+#include <linux/kobject.h>
+
+#include "cpuidle.h"
+
+static unsigned int sysfs_switch;
+static int __init cpuidle_sysfs_setup(char *unused)
+{
+	sysfs_switch = 1;
+	return 1;
+}
+__setup("cpuidle_sysfs_switch", cpuidle_sysfs_setup);
+
+static ssize_t show_available_governors(struct device *dev,
+					struct device_attribute *attr,
+					char *buf)
+{
+	ssize_t i = 0;
+	struct cpuidle_governor *tmp;
+
+	mutex_lock(&cpuidle_lock);
+	list_for_each_entry(tmp, &cpuidle_governors, governor_list) {
+		if (i >= (ssize_t) ((PAGE_SIZE/sizeof(char)) -
+				    CPUIDLE_NAME_LEN - 2))
+			goto out;
+		i += scnprintf(&buf[i], CPUIDLE_NAME_LEN, "%s ", tmp->name);
+	}
+
+out:
+	i+= sprintf(&buf[i], "\n");
+	mutex_unlock(&cpuidle_lock);
+	return i;
+}
+
+static ssize_t show_current_driver(struct device *dev,
+				   struct device_attribute *attr,
+				   char *buf)
+{
+	ssize_t ret;
+	struct cpuidle_driver *drv;
+
+	spin_lock(&cpuidle_driver_lock);
+	drv = cpuidle_get_driver();
+	if (drv)
+		ret = sprintf(buf, "%s\n", drv->name);
+	else
+		ret = sprintf(buf, "none\n");
+	spin_unlock(&cpuidle_driver_lock);
+
+	return ret;
+}
+
+static ssize_t show_current_governor(struct device *dev,
+				     struct device_attribute *attr,
+				     char *buf)
+{
+	ssize_t ret;
+
+	mutex_lock(&cpuidle_lock);
+	if (cpuidle_curr_governor)
+		ret = sprintf(buf, "%s\n", cpuidle_curr_governor->name);
+	else
+		ret = sprintf(buf, "none\n");
+	mutex_unlock(&cpuidle_lock);
+
+	return ret;
+}
+
+static ssize_t store_current_governor(struct device *dev,
+				      struct device_attribute *attr,
+				      const char *buf, size_t count)
+{
+	char gov_name[CPUIDLE_NAME_LEN];
+	int ret = -EINVAL;
+	size_t len = count;
+	struct cpuidle_governor *gov;
+
+	if (!len || len >= sizeof(gov_name))
+		return -EINVAL;
+
+	memcpy(gov_name, buf, len);
+	gov_name[len] = '\0';
+	if (gov_name[len - 1] == '\n')
+		gov_name[--len] = '\0';
+
+	mutex_lock(&cpuidle_lock);
+
+	list_for_each_entry(gov, &cpuidle_governors, governor_list) {
+		if (strlen(gov->name) == len && !strcmp(gov->name, gov_name)) {
+			ret = cpuidle_switch_governor(gov);
+			break;
+		}
+	}
+
+	mutex_unlock(&cpuidle_lock);
+
+	if (ret)
+		return ret;
+	else
+		return count;
+}
+
+static DEVICE_ATTR(current_driver, 0444, show_current_driver, NULL);
+static DEVICE_ATTR(current_governor_ro, 0444, show_current_governor, NULL);
+
+static struct attribute *cpuidle_default_attrs[] = {
+	&dev_attr_current_driver.attr,
+	&dev_attr_current_governor_ro.attr,
+	NULL
+};
+
+static DEVICE_ATTR(available_governors, 0444, show_available_governors, NULL);
+static DEVICE_ATTR(current_governor, 0644, show_current_governor,
+		   store_current_governor);
+
+static struct attribute *cpuidle_switch_attrs[] = {
+	&dev_attr_available_governors.attr,
+	&dev_attr_current_driver.attr,
+	&dev_attr_current_governor.attr,
+	NULL
+};
+
+static struct attribute_group cpuidle_attr_group = {
+	.attrs = cpuidle_default_attrs,
+	.name = "cpuidle",
+};
+
+/**
+ * cpuidle_add_interface - add CPU global sysfs attributes
+ */
+int cpuidle_add_interface(struct device *dev)
+{
+	if (sysfs_switch)
+		cpuidle_attr_group.attrs = cpuidle_switch_attrs;
+
+	return sysfs_create_group(&dev->kobj, &cpuidle_attr_group);
+}
+
+/**
+ * cpuidle_remove_interface - remove CPU global sysfs attributes
+ */
+void cpuidle_remove_interface(struct device *dev)
+{
+	sysfs_remove_group(&dev->kobj, &cpuidle_attr_group);
+}
+
+struct cpuidle_attr {
+	struct attribute attr;
+	ssize_t (*show)(struct cpuidle_device *, char *);
+	ssize_t (*store)(struct cpuidle_device *, const char *, size_t count);
+};
+
+#define define_one_ro(_name, show) \
+	static struct cpuidle_attr attr_##_name = __ATTR(_name, 0444, show, NULL)
+#define define_one_rw(_name, show, store) \
+	static struct cpuidle_attr attr_##_name = __ATTR(_name, 0644, show, store)
+
+#define attr_to_cpuidleattr(a) container_of(a, struct cpuidle_attr, attr)
+
+struct cpuidle_device_kobj {
+	struct cpuidle_device *dev;
+	struct completion kobj_unregister;
+	struct kobject kobj;
+};
+
+static inline struct cpuidle_device *to_cpuidle_device(struct kobject *kobj)
+{
+	struct cpuidle_device_kobj *kdev =
+		container_of(kobj, struct cpuidle_device_kobj, kobj);
+
+	return kdev->dev;
+}
+
+static ssize_t cpuidle_show(struct kobject *kobj, struct attribute *attr,
+			    char *buf)
+{
+	int ret = -EIO;
+	struct cpuidle_device *dev = to_cpuidle_device(kobj);
+	struct cpuidle_attr *cattr = attr_to_cpuidleattr(attr);
+
+	if (cattr->show) {
+		mutex_lock(&cpuidle_lock);
+		ret = cattr->show(dev, buf);
+		mutex_unlock(&cpuidle_lock);
+	}
+	return ret;
+}
+
+static ssize_t cpuidle_store(struct kobject *kobj, struct attribute *attr,
+			     const char *buf, size_t count)
+{
+	int ret = -EIO;
+	struct cpuidle_device *dev = to_cpuidle_device(kobj);
+	struct cpuidle_attr *cattr = attr_to_cpuidleattr(attr);
+
+	if (cattr->store) {
+		mutex_lock(&cpuidle_lock);
+		ret = cattr->store(dev, buf, count);
+		mutex_unlock(&cpuidle_lock);
+	}
+	return ret;
+}
+
+static const struct sysfs_ops cpuidle_sysfs_ops = {
+	.show = cpuidle_show,
+	.store = cpuidle_store,
+};
+
+static void cpuidle_sysfs_release(struct kobject *kobj)
+{
+	struct cpuidle_device_kobj *kdev =
+		container_of(kobj, struct cpuidle_device_kobj, kobj);
+
+	complete(&kdev->kobj_unregister);
+}
+
+static struct kobj_type ktype_cpuidle = {
+	.sysfs_ops = &cpuidle_sysfs_ops,
+	.release = cpuidle_sysfs_release,
+};
+
+struct cpuidle_state_attr {
+	struct attribute attr;
+	ssize_t (*show)(struct cpuidle_state *, \
+					struct cpuidle_state_usage *, char *);
+	ssize_t (*store)(struct cpuidle_state *, \
+			struct cpuidle_state_usage *, const char *, size_t);
+};
+
+#define define_one_state_ro(_name, show) \
+static struct cpuidle_state_attr attr_##_name = __ATTR(_name, 0444, show, NULL)
+
+#define define_one_state_rw(_name, show, store) \
+static struct cpuidle_state_attr attr_##_name = __ATTR(_name, 0644, show, store)
+
+#define define_show_state_function(_name) \
+static ssize_t show_state_##_name(struct cpuidle_state *state, \
+			 struct cpuidle_state_usage *state_usage, char *buf) \
+{ \
+	return sprintf(buf, "%u\n", state->_name);\
+}
+
+#define define_store_state_ull_function(_name) \
+static ssize_t store_state_##_name(struct cpuidle_state *state, \
+				   struct cpuidle_state_usage *state_usage, \
+				   const char *buf, size_t size)	\
+{ \
+	unsigned long long value; \
+	int err; \
+	if (!capable(CAP_SYS_ADMIN)) \
+		return -EPERM; \
+	err = kstrtoull(buf, 0, &value); \
+	if (err) \
+		return err; \
+	if (value) \
+		state_usage->_name = 1; \
+	else \
+		state_usage->_name = 0; \
+	return size; \
+}
+
+#define define_show_state_ull_function(_name) \
+static ssize_t show_state_##_name(struct cpuidle_state *state, \
+				  struct cpuidle_state_usage *state_usage, \
+				  char *buf)				\
+{ \
+	return sprintf(buf, "%llu\n", state_usage->_name);\
+}
+
+#define define_show_state_str_function(_name) \
+static ssize_t show_state_##_name(struct cpuidle_state *state, \
+				  struct cpuidle_state_usage *state_usage, \
+				  char *buf)				\
+{ \
+	if (state->_name[0] == '\0')\
+		return sprintf(buf, "<null>\n");\
+	return sprintf(buf, "%s\n", state->_name);\
+}
+
+define_show_state_function(exit_latency)
+define_show_state_function(target_residency)
+define_show_state_function(power_usage)
+define_show_state_ull_function(usage)
+define_show_state_ull_function(time)
+define_show_state_str_function(name)
+define_show_state_str_function(desc)
+define_show_state_ull_function(disable)
+define_store_state_ull_function(disable)
+
+define_one_state_ro(name, show_state_name);
+define_one_state_ro(desc, show_state_desc);
+define_one_state_ro(latency, show_state_exit_latency);
+define_one_state_ro(residency, show_state_target_residency);
+define_one_state_ro(power, show_state_power_usage);
+define_one_state_ro(usage, show_state_usage);
+define_one_state_ro(time, show_state_time);
+define_one_state_rw(disable, show_state_disable, store_state_disable);
+
+static struct attribute *cpuidle_state_default_attrs[] = {
+	&attr_name.attr,
+	&attr_desc.attr,
+	&attr_latency.attr,
+	&attr_residency.attr,
+	&attr_power.attr,
+	&attr_usage.attr,
+	&attr_time.attr,
+	&attr_disable.attr,
+	NULL
+};
+
+struct cpuidle_state_kobj {
+	struct cpuidle_state *state;
+	struct cpuidle_state_usage *state_usage;
+	struct completion kobj_unregister;
+	struct kobject kobj;
+};
+
+#define kobj_to_state_obj(k) container_of(k, struct cpuidle_state_kobj, kobj)
+#define kobj_to_state(k) (kobj_to_state_obj(k)->state)
+#define kobj_to_state_usage(k) (kobj_to_state_obj(k)->state_usage)
+#define attr_to_stateattr(a) container_of(a, struct cpuidle_state_attr, attr)
+
+static ssize_t cpuidle_state_show(struct kobject *kobj, struct attribute *attr,
+				  char * buf)
+{
+	int ret = -EIO;
+	struct cpuidle_state *state = kobj_to_state(kobj);
+	struct cpuidle_state_usage *state_usage = kobj_to_state_usage(kobj);
+	struct cpuidle_state_attr * cattr = attr_to_stateattr(attr);
+
+	if (cattr->show)
+		ret = cattr->show(state, state_usage, buf);
+
+	return ret;
+}
+
+static ssize_t cpuidle_state_store(struct kobject *kobj, struct attribute *attr,
+				   const char *buf, size_t size)
+{
+	int ret = -EIO;
+	struct cpuidle_state *state = kobj_to_state(kobj);
+	struct cpuidle_state_usage *state_usage = kobj_to_state_usage(kobj);
+	struct cpuidle_state_attr *cattr = attr_to_stateattr(attr);
+
+	if (cattr->store)
+		ret = cattr->store(state, state_usage, buf, size);
+
+	return ret;
+}
+
+static const struct sysfs_ops cpuidle_state_sysfs_ops = {
+	.show = cpuidle_state_show,
+	.store = cpuidle_state_store,
+};
+
+static void cpuidle_state_sysfs_release(struct kobject *kobj)
+{
+	struct cpuidle_state_kobj *state_obj = kobj_to_state_obj(kobj);
+
+	complete(&state_obj->kobj_unregister);
+}
+
+static struct kobj_type ktype_state_cpuidle = {
+	.sysfs_ops = &cpuidle_state_sysfs_ops,
+	.default_attrs = cpuidle_state_default_attrs,
+	.release = cpuidle_state_sysfs_release,
+};
+
+static inline void cpuidle_free_state_kobj(struct cpuidle_device *device, int i)
+{
+	kobject_put(&device->kobjs[i]->kobj);
+	wait_for_completion(&device->kobjs[i]->kobj_unregister);
+	kfree(device->kobjs[i]);
+	device->kobjs[i] = NULL;
+}
+
+/**
+ * cpuidle_add_state_sysfs - adds cpuidle states sysfs attributes
+ * @device: the target device
+ */
+static int cpuidle_add_state_sysfs(struct cpuidle_device *device)
+{
+	int i, ret = -ENOMEM;
+	struct cpuidle_state_kobj *kobj;
+	struct cpuidle_device_kobj *kdev = device->kobj_dev;
+	struct cpuidle_driver *drv = cpuidle_get_cpu_driver(device);
+
+	/* state statistics */
+	for (i = 0; i < drv->state_count; i++) {
+		kobj = kzalloc(sizeof(struct cpuidle_state_kobj), GFP_KERNEL);
+		if (!kobj)
+			goto error_state;
+		kobj->state = &drv->states[i];
+		kobj->state_usage = &device->states_usage[i];
+		init_completion(&kobj->kobj_unregister);
+
+		ret = kobject_init_and_add(&kobj->kobj, &ktype_state_cpuidle,
+					   &kdev->kobj, "state%d", i);
+		if (ret) {
+			kfree(kobj);
+			goto error_state;
+		}
+		kobject_uevent(&kobj->kobj, KOBJ_ADD);
+		device->kobjs[i] = kobj;
+	}
+
+	return 0;
+
+error_state:
+	for (i = i - 1; i >= 0; i--)
+		cpuidle_free_state_kobj(device, i);
+	return ret;
+}
+
+/**
+ * cpuidle_remove_driver_sysfs - removes the cpuidle states sysfs attributes
+ * @device: the target device
+ */
+static void cpuidle_remove_state_sysfs(struct cpuidle_device *device)
+{
+	struct cpuidle_driver *drv = cpuidle_get_cpu_driver(device);
+	int i;
+
+	for (i = 0; i < drv->state_count; i++)
+		cpuidle_free_state_kobj(device, i);
+}
+
+#ifdef CONFIG_CPU_IDLE_MULTIPLE_DRIVERS
+#define kobj_to_driver_kobj(k) container_of(k, struct cpuidle_driver_kobj, kobj)
+#define attr_to_driver_attr(a) container_of(a, struct cpuidle_driver_attr, attr)
+
+#define define_one_driver_ro(_name, show)                       \
+	static struct cpuidle_driver_attr attr_driver_##_name = \
+		__ATTR(_name, 0444, show, NULL)
+
+struct cpuidle_driver_kobj {
+	struct cpuidle_driver *drv;
+	struct completion kobj_unregister;
+	struct kobject kobj;
+};
+
+struct cpuidle_driver_attr {
+	struct attribute attr;
+	ssize_t (*show)(struct cpuidle_driver *, char *);
+	ssize_t (*store)(struct cpuidle_driver *, const char *, size_t);
+};
+
+static ssize_t show_driver_name(struct cpuidle_driver *drv, char *buf)
+{
+	ssize_t ret;
+
+	spin_lock(&cpuidle_driver_lock);
+	ret = sprintf(buf, "%s\n", drv ? drv->name : "none");
+	spin_unlock(&cpuidle_driver_lock);
+
+	return ret;
+}
+
+static void cpuidle_driver_sysfs_release(struct kobject *kobj)
+{
+	struct cpuidle_driver_kobj *driver_kobj = kobj_to_driver_kobj(kobj);
+	complete(&driver_kobj->kobj_unregister);
+}
+
+static ssize_t cpuidle_driver_show(struct kobject *kobj, struct attribute *attr,
+				   char *buf)
+{
+	int ret = -EIO;
+	struct cpuidle_driver_kobj *driver_kobj = kobj_to_driver_kobj(kobj);
+	struct cpuidle_driver_attr *dattr = attr_to_driver_attr(attr);
+
+	if (dattr->show)
+		ret = dattr->show(driver_kobj->drv, buf);
+
+	return ret;
+}
+
+static ssize_t cpuidle_driver_store(struct kobject *kobj, struct attribute *attr,
+				    const char *buf, size_t size)
+{
+	int ret = -EIO;
+	struct cpuidle_driver_kobj *driver_kobj = kobj_to_driver_kobj(kobj);
+	struct cpuidle_driver_attr *dattr = attr_to_driver_attr(attr);
+
+	if (dattr->store)
+		ret = dattr->store(driver_kobj->drv, buf, size);
+
+	return ret;
+}
+
+define_one_driver_ro(name, show_driver_name);
+
+static const struct sysfs_ops cpuidle_driver_sysfs_ops = {
+	.show = cpuidle_driver_show,
+	.store = cpuidle_driver_store,
+};
+
+static struct attribute *cpuidle_driver_default_attrs[] = {
+	&attr_driver_name.attr,
+	NULL
+};
+
+static struct kobj_type ktype_driver_cpuidle = {
+	.sysfs_ops = &cpuidle_driver_sysfs_ops,
+	.default_attrs = cpuidle_driver_default_attrs,
+	.release = cpuidle_driver_sysfs_release,
+};
+
+/**
+ * cpuidle_add_driver_sysfs - adds the driver name sysfs attribute
+ * @device: the target device
+ */
+static int cpuidle_add_driver_sysfs(struct cpuidle_device *dev)
+{
+	struct cpuidle_driver_kobj *kdrv;
+	struct cpuidle_device_kobj *kdev = dev->kobj_dev;
+	struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev);
+	int ret;
+
+	kdrv = kzalloc(sizeof(*kdrv), GFP_KERNEL);
+	if (!kdrv)
+		return -ENOMEM;
+
+	kdrv->drv = drv;
+	init_completion(&kdrv->kobj_unregister);
+
+	ret = kobject_init_and_add(&kdrv->kobj, &ktype_driver_cpuidle,
+				   &kdev->kobj, "driver");
+	if (ret) {
+		kfree(kdrv);
+		return ret;
+	}
+
+	kobject_uevent(&kdrv->kobj, KOBJ_ADD);
+	dev->kobj_driver = kdrv;
+
+	return ret;
+}
+
+/**
+ * cpuidle_remove_driver_sysfs - removes the driver name sysfs attribute
+ * @device: the target device
+ */
+static void cpuidle_remove_driver_sysfs(struct cpuidle_device *dev)
+{
+	struct cpuidle_driver_kobj *kdrv = dev->kobj_driver;
+	kobject_put(&kdrv->kobj);
+	wait_for_completion(&kdrv->kobj_unregister);
+	kfree(kdrv);
+}
+#else
+static inline int cpuidle_add_driver_sysfs(struct cpuidle_device *dev)
+{
+	return 0;
+}
+
+static inline void cpuidle_remove_driver_sysfs(struct cpuidle_device *dev)
+{
+	;
+}
+#endif
+
+/**
+ * cpuidle_add_device_sysfs - adds device specific sysfs attributes
+ * @device: the target device
+ */
+int cpuidle_add_device_sysfs(struct cpuidle_device *device)
+{
+	int ret;
+
+	ret = cpuidle_add_state_sysfs(device);
+	if (ret)
+		return ret;
+
+	ret = cpuidle_add_driver_sysfs(device);
+	if (ret)
+		cpuidle_remove_state_sysfs(device);
+	return ret;
+}
+
+/**
+ * cpuidle_remove_device_sysfs : removes device specific sysfs attributes
+ * @device : the target device
+ */
+void cpuidle_remove_device_sysfs(struct cpuidle_device *device)
+{
+	cpuidle_remove_driver_sysfs(device);
+	cpuidle_remove_state_sysfs(device);
+}
+
+/**
+ * cpuidle_add_sysfs - creates a sysfs instance for the target device
+ * @dev: the target device
+ */
+int cpuidle_add_sysfs(struct cpuidle_device *dev)
+{
+	struct cpuidle_device_kobj *kdev;
+	struct device *cpu_dev = get_cpu_device((unsigned long)dev->cpu);
+	int error;
+
+	kdev = kzalloc(sizeof(*kdev), GFP_KERNEL);
+	if (!kdev)
+		return -ENOMEM;
+	kdev->dev = dev;
+	dev->kobj_dev = kdev;
+
+	init_completion(&kdev->kobj_unregister);
+
+	error = kobject_init_and_add(&kdev->kobj, &ktype_cpuidle, &cpu_dev->kobj,
+				   "cpuidle");
+	if (error) {
+		kfree(kdev);
+		return error;
+	}
+
+	kobject_uevent(&kdev->kobj, KOBJ_ADD);
+
+	return 0;
+}
+
+/**
+ * cpuidle_remove_sysfs - deletes a sysfs instance on the target device
+ * @dev: the target device
+ */
+void cpuidle_remove_sysfs(struct cpuidle_device *dev)
+{
+	struct cpuidle_device_kobj *kdev = dev->kobj_dev;
+
+	kobject_put(&kdev->kobj);
+	wait_for_completion(&kdev->kobj_unregister);
+	kfree(kdev);
+}