Fixed MTP to work with TWRP

arch/powerpc/kernel/idle_6xx.S

@@ -0,0 +1,197 @@
+/*
+ *  This file contains the power_save function for 6xx & 7xxx CPUs
+ *  rewritten in assembler
+ *
+ *  Warning ! This code assumes that if your machine has a 750fx
+ *  it will have PLL 1 set to low speed mode (used during NAP/DOZE).
+ *  if this is not the case some additional changes will have to
+ *  be done to check a runtime var (a bit like powersave-nap)
+ *
+ *  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/threads.h>
+#include <asm/reg.h>
+#include <asm/page.h>
+#include <asm/cputable.h>
+#include <asm/thread_info.h>
+#include <asm/ppc_asm.h>
+#include <asm/asm-offsets.h>
+
+	.text
+
+/*
+ * Init idle, called at early CPU setup time from head.S for each CPU
+ * Make sure no rest of NAP mode remains in HID0, save default
+ * values for some CPU specific registers. Called with r24
+ * containing CPU number and r3 reloc offset
+ */
+_GLOBAL(init_idle_6xx)
+BEGIN_FTR_SECTION
+	mfspr	r4,SPRN_HID0
+	rlwinm	r4,r4,0,10,8	/* Clear NAP */
+	mtspr	SPRN_HID0, r4
+	b	1f
+END_FTR_SECTION_IFSET(CPU_FTR_CAN_NAP)
+	blr
+1:
+	slwi	r5,r24,2
+	add	r5,r5,r3
+BEGIN_FTR_SECTION
+	mfspr	r4,SPRN_MSSCR0
+	addis	r6,r5, nap_save_msscr0@ha
+	stw	r4,nap_save_msscr0@l(r6)
+END_FTR_SECTION_IFSET(CPU_FTR_NAP_DISABLE_L2_PR)
+BEGIN_FTR_SECTION
+	mfspr	r4,SPRN_HID1
+	addis	r6,r5,nap_save_hid1@ha
+	stw	r4,nap_save_hid1@l(r6)
+END_FTR_SECTION_IFSET(CPU_FTR_DUAL_PLL_750FX)
+	blr
+
+/*
+ * Here is the power_save_6xx function. This could eventually be
+ * split into several functions & changing the function pointer
+ * depending on the various features.
+ */
+_GLOBAL(ppc6xx_idle)
+	/* Check if we can nap or doze, put HID0 mask in r3
+	 */
+	lis	r3, 0
+BEGIN_FTR_SECTION
+	lis	r3,HID0_DOZE@h
+END_FTR_SECTION_IFSET(CPU_FTR_CAN_DOZE)
+BEGIN_FTR_SECTION
+	/* We must dynamically check for the NAP feature as it
+	 * can be cleared by CPU init after the fixups are done
+	 */
+	lis	r4,cur_cpu_spec@ha
+	lwz	r4,cur_cpu_spec@l(r4)
+	lwz	r4,CPU_SPEC_FEATURES(r4)
+	andi.	r0,r4,CPU_FTR_CAN_NAP
+	beq	1f
+	/* Now check if user or arch enabled NAP mode */
+	lis	r4,powersave_nap@ha
+	lwz	r4,powersave_nap@l(r4)
+	cmpwi	0,r4,0
+	beq	1f
+	lis	r3,HID0_NAP@h
+1:	
+END_FTR_SECTION_IFSET(CPU_FTR_CAN_NAP)
+	cmpwi	0,r3,0
+	beqlr
+
+	/* Some pre-nap cleanups needed on some CPUs */
+	andis.	r0,r3,HID0_NAP@h
+	beq	2f
+BEGIN_FTR_SECTION
+	/* Disable L2 prefetch on some 745x and try to ensure
+	 * L2 prefetch engines are idle. As explained by errata
+	 * text, we can't be sure they are, we just hope very hard
+	 * that well be enough (sic !). At least I noticed Apple
+	 * doesn't even bother doing the dcbf's here...
+	 */
+	mfspr	r4,SPRN_MSSCR0
+	rlwinm	r4,r4,0,0,29
+	sync
+	mtspr	SPRN_MSSCR0,r4
+	sync
+	isync
+	lis	r4,KERNELBASE@h
+	dcbf	0,r4
+	dcbf	0,r4
+	dcbf	0,r4
+	dcbf	0,r4
+END_FTR_SECTION_IFSET(CPU_FTR_NAP_DISABLE_L2_PR)
+2:
+BEGIN_FTR_SECTION
+	/* Go to low speed mode on some 750FX */
+	lis	r4,powersave_lowspeed@ha
+	lwz	r4,powersave_lowspeed@l(r4)
+	cmpwi	0,r4,0
+	beq	1f
+	mfspr	r4,SPRN_HID1
+	oris	r4,r4,0x0001
+	mtspr	SPRN_HID1,r4
+1:	
+END_FTR_SECTION_IFSET(CPU_FTR_DUAL_PLL_750FX)
+
+	/* Go to NAP or DOZE now */	
+	mfspr	r4,SPRN_HID0
+	lis	r5,(HID0_NAP|HID0_SLEEP)@h
+BEGIN_FTR_SECTION
+	oris	r5,r5,HID0_DOZE@h
+END_FTR_SECTION_IFSET(CPU_FTR_CAN_DOZE)
+	andc	r4,r4,r5
+	or	r4,r4,r3
+BEGIN_FTR_SECTION
+	oris	r4,r4,HID0_DPM@h	/* that should be done once for all  */
+END_FTR_SECTION_IFCLR(CPU_FTR_NO_DPM)
+	mtspr	SPRN_HID0,r4
+BEGIN_FTR_SECTION
+	DSSALL
+	sync
+END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
+	CURRENT_THREAD_INFO(r9, r1)
+	lwz	r8,TI_LOCAL_FLAGS(r9)	/* set napping bit */
+	ori	r8,r8,_TLF_NAPPING	/* so when we take an exception */
+	stw	r8,TI_LOCAL_FLAGS(r9)	/* it will return to our caller */
+	mfmsr	r7
+	ori	r7,r7,MSR_EE
+	oris	r7,r7,MSR_POW@h
+1:	sync
+	mtmsr	r7
+	isync
+	b	1b
+
+/*
+ * Return from NAP/DOZE mode, restore some CPU specific registers,
+ * we are called with DR/IR still off and r2 containing physical
+ * address of current.  R11 points to the exception frame (physical
+ * address).  We have to preserve r10.
+ */
+_GLOBAL(power_save_ppc32_restore)
+	lwz	r9,_LINK(r11)		/* interrupted in ppc6xx_idle: */
+	stw	r9,_NIP(r11)		/* make it do a blr */
+
+#ifdef CONFIG_SMP
+	CURRENT_THREAD_INFO(r12, r11)
+	lwz	r11,TI_CPU(r12)		/* get cpu number * 4 */
+	slwi	r11,r11,2
+#else
+	li	r11,0
+#endif
+	/* Todo make sure all these are in the same page
+	 * and load r11 (@ha part + CPU offset) only once
+	 */
+BEGIN_FTR_SECTION
+	mfspr	r9,SPRN_HID0
+	andis.	r9,r9,HID0_NAP@h
+	beq	1f
+	addis	r9,r11,(nap_save_msscr0-KERNELBASE)@ha
+	lwz	r9,nap_save_msscr0@l(r9)
+	mtspr	SPRN_MSSCR0, r9
+	sync
+	isync
+1:
+END_FTR_SECTION_IFSET(CPU_FTR_NAP_DISABLE_L2_PR)
+BEGIN_FTR_SECTION
+	addis	r9,r11,(nap_save_hid1-KERNELBASE)@ha
+	lwz	r9,nap_save_hid1@l(r9)
+	mtspr	SPRN_HID1, r9
+END_FTR_SECTION_IFSET(CPU_FTR_DUAL_PLL_750FX)
+	b	transfer_to_handler_cont
+
+	.data
+
+_GLOBAL(nap_save_msscr0)
+	.space	4*NR_CPUS
+
+_GLOBAL(nap_save_hid1)
+	.space	4*NR_CPUS
+
+_GLOBAL(powersave_lowspeed)
+	.long	0