Fixed MTP to work with TWRP

arch/ia64/kernel/salinfo.c

@@ -0,0 +1,704 @@
+/*
+ * salinfo.c
+ *
+ * Creates entries in /proc/sal for various system features.
+ *
+ * Copyright (c) 2003, 2006 Silicon Graphics, Inc.  All rights reserved.
+ * Copyright (c) 2003 Hewlett-Packard Co
+ *	Bjorn Helgaas <bjorn.helgaas@hp.com>
+ *
+ * 10/30/2001	jbarnes@sgi.com		copied much of Stephane's palinfo
+ *					code to create this file
+ * Oct 23 2003	kaos@sgi.com
+ *   Replace IPI with set_cpus_allowed() to read a record from the required cpu.
+ *   Redesign salinfo log processing to separate interrupt and user space
+ *   contexts.
+ *   Cache the record across multi-block reads from user space.
+ *   Support > 64 cpus.
+ *   Delete module_exit and MOD_INC/DEC_COUNT, salinfo cannot be a module.
+ *
+ * Jan 28 2004	kaos@sgi.com
+ *   Periodically check for outstanding MCA or INIT records.
+ *
+ * Dec  5 2004	kaos@sgi.com
+ *   Standardize which records are cleared automatically.
+ *
+ * Aug 18 2005	kaos@sgi.com
+ *   mca.c may not pass a buffer, a NULL buffer just indicates that a new
+ *   record is available in SAL.
+ *   Replace some NR_CPUS by cpus_online, for hotplug cpu.
+ *
+ * Jan  5 2006        kaos@sgi.com
+ *   Handle hotplug cpus coming online.
+ *   Handle hotplug cpus going offline while they still have outstanding records.
+ *   Use the cpu_* macros consistently.
+ *   Replace the counting semaphore with a mutex and a test if the cpumask is non-empty.
+ *   Modify the locking to make the test for "work to do" an atomic operation.
+ */
+
+#include <linux/capability.h>
+#include <linux/cpu.h>
+#include <linux/types.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#include <linux/module.h>
+#include <linux/smp.h>
+#include <linux/timer.h>
+#include <linux/vmalloc.h>
+#include <linux/semaphore.h>
+
+#include <asm/sal.h>
+#include <asm/uaccess.h>
+
+MODULE_AUTHOR("Jesse Barnes <jbarnes@sgi.com>");
+MODULE_DESCRIPTION("/proc interface to IA-64 SAL features");
+MODULE_LICENSE("GPL");
+
+static const struct file_operations proc_salinfo_fops;
+
+typedef struct {
+	const char		*name;		/* name of the proc entry */
+	unsigned long           feature;        /* feature bit */
+	struct proc_dir_entry	*entry;		/* registered entry (removal) */
+} salinfo_entry_t;
+
+/*
+ * List {name,feature} pairs for every entry in /proc/sal/<feature>
+ * that this module exports
+ */
+static const salinfo_entry_t salinfo_entries[]={
+	{ "bus_lock",           IA64_SAL_PLATFORM_FEATURE_BUS_LOCK, },
+	{ "irq_redirection",	IA64_SAL_PLATFORM_FEATURE_IRQ_REDIR_HINT, },
+	{ "ipi_redirection",	IA64_SAL_PLATFORM_FEATURE_IPI_REDIR_HINT, },
+	{ "itc_drift",		IA64_SAL_PLATFORM_FEATURE_ITC_DRIFT, },
+};
+
+#define NR_SALINFO_ENTRIES ARRAY_SIZE(salinfo_entries)
+
+static char *salinfo_log_name[] = {
+	"mca",
+	"init",
+	"cmc",
+	"cpe",
+};
+
+static struct proc_dir_entry *salinfo_proc_entries[
+	ARRAY_SIZE(salinfo_entries) +			/* /proc/sal/bus_lock */
+	ARRAY_SIZE(salinfo_log_name) +			/* /proc/sal/{mca,...} */
+	(2 * ARRAY_SIZE(salinfo_log_name)) +		/* /proc/sal/mca/{event,data} */
+	1];						/* /proc/sal */
+
+/* Some records we get ourselves, some are accessed as saved data in buffers
+ * that are owned by mca.c.
+ */
+struct salinfo_data_saved {
+	u8*			buffer;
+	u64			size;
+	u64			id;
+	int			cpu;
+};
+
+/* State transitions.  Actions are :-
+ *   Write "read <cpunum>" to the data file.
+ *   Write "clear <cpunum>" to the data file.
+ *   Write "oemdata <cpunum> <offset> to the data file.
+ *   Read from the data file.
+ *   Close the data file.
+ *
+ * Start state is NO_DATA.
+ *
+ * NO_DATA
+ *    write "read <cpunum>" -> NO_DATA or LOG_RECORD.
+ *    write "clear <cpunum>" -> NO_DATA or LOG_RECORD.
+ *    write "oemdata <cpunum> <offset> -> return -EINVAL.
+ *    read data -> return EOF.
+ *    close -> unchanged.  Free record areas.
+ *
+ * LOG_RECORD
+ *    write "read <cpunum>" -> NO_DATA or LOG_RECORD.
+ *    write "clear <cpunum>" -> NO_DATA or LOG_RECORD.
+ *    write "oemdata <cpunum> <offset> -> format the oem data, goto OEMDATA.
+ *    read data -> return the INIT/MCA/CMC/CPE record.
+ *    close -> unchanged.  Keep record areas.
+ *
+ * OEMDATA
+ *    write "read <cpunum>" -> NO_DATA or LOG_RECORD.
+ *    write "clear <cpunum>" -> NO_DATA or LOG_RECORD.
+ *    write "oemdata <cpunum> <offset> -> format the oem data, goto OEMDATA.
+ *    read data -> return the formatted oemdata.
+ *    close -> unchanged.  Keep record areas.
+ *
+ * Closing the data file does not change the state.  This allows shell scripts
+ * to manipulate salinfo data, each shell redirection opens the file, does one
+ * action then closes it again.  The record areas are only freed at close when
+ * the state is NO_DATA.
+ */
+enum salinfo_state {
+	STATE_NO_DATA,
+	STATE_LOG_RECORD,
+	STATE_OEMDATA,
+};
+
+struct salinfo_data {
+	cpumask_t		cpu_event;	/* which cpus have outstanding events */
+	struct semaphore	mutex;
+	u8			*log_buffer;
+	u64			log_size;
+	u8			*oemdata;	/* decoded oem data */
+	u64			oemdata_size;
+	int			open;		/* single-open to prevent races */
+	u8			type;
+	u8			saved_num;	/* using a saved record? */
+	enum salinfo_state	state :8;	/* processing state */
+	u8			padding;
+	int			cpu_check;	/* next CPU to check */
+	struct salinfo_data_saved data_saved[5];/* save last 5 records from mca.c, must be < 255 */
+};
+
+static struct salinfo_data salinfo_data[ARRAY_SIZE(salinfo_log_name)];
+
+static DEFINE_SPINLOCK(data_lock);
+static DEFINE_SPINLOCK(data_saved_lock);
+
+/** salinfo_platform_oemdata - optional callback to decode oemdata from an error
+ * record.
+ * @sect_header: pointer to the start of the section to decode.
+ * @oemdata: returns vmalloc area containing the decoded output.
+ * @oemdata_size: returns length of decoded output (strlen).
+ *
+ * Description: If user space asks for oem data to be decoded by the kernel
+ * and/or prom and the platform has set salinfo_platform_oemdata to the address
+ * of a platform specific routine then call that routine.  salinfo_platform_oemdata
+ * vmalloc's and formats its output area, returning the address of the text
+ * and its strlen.  Returns 0 for success, -ve for error.  The callback is
+ * invoked on the cpu that generated the error record.
+ */
+int (*salinfo_platform_oemdata)(const u8 *sect_header, u8 **oemdata, u64 *oemdata_size);
+
+struct salinfo_platform_oemdata_parms {
+	const u8 *efi_guid;
+	u8 **oemdata;
+	u64 *oemdata_size;
+	int ret;
+};
+
+/* Kick the mutex that tells user space that there is work to do.  Instead of
+ * trying to track the state of the mutex across multiple cpus, in user
+ * context, interrupt context, non-maskable interrupt context and hotplug cpu,
+ * it is far easier just to grab the mutex if it is free then release it.
+ *
+ * This routine must be called with data_saved_lock held, to make the down/up
+ * operation atomic.
+ */
+static void
+salinfo_work_to_do(struct salinfo_data *data)
+{
+	(void)(down_trylock(&data->mutex) ?: 0);
+	up(&data->mutex);
+}
+
+static void
+salinfo_platform_oemdata_cpu(void *context)
+{
+	struct salinfo_platform_oemdata_parms *parms = context;
+	parms->ret = salinfo_platform_oemdata(parms->efi_guid, parms->oemdata, parms->oemdata_size);
+}
+
+static void
+shift1_data_saved (struct salinfo_data *data, int shift)
+{
+	memcpy(data->data_saved+shift, data->data_saved+shift+1,
+	       (ARRAY_SIZE(data->data_saved) - (shift+1)) * sizeof(data->data_saved[0]));
+	memset(data->data_saved + ARRAY_SIZE(data->data_saved) - 1, 0,
+	       sizeof(data->data_saved[0]));
+}
+
+/* This routine is invoked in interrupt context.  Note: mca.c enables
+ * interrupts before calling this code for CMC/CPE.  MCA and INIT events are
+ * not irq safe, do not call any routines that use spinlocks, they may deadlock.
+ * MCA and INIT records are recorded, a timer event will look for any
+ * outstanding events and wake up the user space code.
+ *
+ * The buffer passed from mca.c points to the output from ia64_log_get. This is
+ * a persistent buffer but its contents can change between the interrupt and
+ * when user space processes the record.  Save the record id to identify
+ * changes.  If the buffer is NULL then just update the bitmap.
+ */
+void
+salinfo_log_wakeup(int type, u8 *buffer, u64 size, int irqsafe)
+{
+	struct salinfo_data *data = salinfo_data + type;
+	struct salinfo_data_saved *data_saved;
+	unsigned long flags = 0;
+	int i;
+	int saved_size = ARRAY_SIZE(data->data_saved);
+
+	BUG_ON(type >= ARRAY_SIZE(salinfo_log_name));
+
+	if (irqsafe)
+		spin_lock_irqsave(&data_saved_lock, flags);
+	if (buffer) {
+		for (i = 0, data_saved = data->data_saved; i < saved_size; ++i, ++data_saved) {
+			if (!data_saved->buffer)
+				break;
+		}
+		if (i == saved_size) {
+			if (!data->saved_num) {
+				shift1_data_saved(data, 0);
+				data_saved = data->data_saved + saved_size - 1;
+			} else
+				data_saved = NULL;
+		}
+		if (data_saved) {
+			data_saved->cpu = smp_processor_id();
+			data_saved->id = ((sal_log_record_header_t *)buffer)->id;
+			data_saved->size = size;
+			data_saved->buffer = buffer;
+		}
+	}
+	cpu_set(smp_processor_id(), data->cpu_event);
+	if (irqsafe) {
+		salinfo_work_to_do(data);
+		spin_unlock_irqrestore(&data_saved_lock, flags);
+	}
+}
+
+/* Check for outstanding MCA/INIT records every minute (arbitrary) */
+#define SALINFO_TIMER_DELAY (60*HZ)
+static struct timer_list salinfo_timer;
+extern void ia64_mlogbuf_dump(void);
+
+static void
+salinfo_timeout_check(struct salinfo_data *data)
+{
+	unsigned long flags;
+	if (!data->open)
+		return;
+	if (!cpus_empty(data->cpu_event)) {
+		spin_lock_irqsave(&data_saved_lock, flags);
+		salinfo_work_to_do(data);
+		spin_unlock_irqrestore(&data_saved_lock, flags);
+	}
+}
+
+static void
+salinfo_timeout (unsigned long arg)
+{
+	ia64_mlogbuf_dump();
+	salinfo_timeout_check(salinfo_data + SAL_INFO_TYPE_MCA);
+	salinfo_timeout_check(salinfo_data + SAL_INFO_TYPE_INIT);
+	salinfo_timer.expires = jiffies + SALINFO_TIMER_DELAY;
+	add_timer(&salinfo_timer);
+}
+
+static int
+salinfo_event_open(struct inode *inode, struct file *file)
+{
+	if (!capable(CAP_SYS_ADMIN))
+		return -EPERM;
+	return 0;
+}
+
+static ssize_t
+salinfo_event_read(struct file *file, char __user *buffer, size_t count, loff_t *ppos)
+{
+	struct salinfo_data *data = PDE_DATA(file_inode(file));
+	char cmd[32];
+	size_t size;
+	int i, n, cpu = -1;
+
+retry:
+	if (cpus_empty(data->cpu_event) && down_trylock(&data->mutex)) {
+		if (file->f_flags & O_NONBLOCK)
+			return -EAGAIN;
+		if (down_interruptible(&data->mutex))
+			return -EINTR;
+	}
+
+	n = data->cpu_check;
+	for (i = 0; i < nr_cpu_ids; i++) {
+		if (cpu_isset(n, data->cpu_event)) {
+			if (!cpu_online(n)) {
+				cpu_clear(n, data->cpu_event);
+				continue;
+			}
+			cpu = n;
+			break;
+		}
+		if (++n == nr_cpu_ids)
+			n = 0;
+	}
+
+	if (cpu == -1)
+		goto retry;
+
+	ia64_mlogbuf_dump();
+
+	/* for next read, start checking at next CPU */
+	data->cpu_check = cpu;
+	if (++data->cpu_check == nr_cpu_ids)
+		data->cpu_check = 0;
+
+	snprintf(cmd, sizeof(cmd), "read %d\n", cpu);
+
+	size = strlen(cmd);
+	if (size > count)
+		size = count;
+	if (copy_to_user(buffer, cmd, size))
+		return -EFAULT;
+
+	return size;
+}
+
+static const struct file_operations salinfo_event_fops = {
+	.open  = salinfo_event_open,
+	.read  = salinfo_event_read,
+	.llseek = noop_llseek,
+};
+
+static int
+salinfo_log_open(struct inode *inode, struct file *file)
+{
+	struct salinfo_data *data = PDE_DATA(inode);
+
+	if (!capable(CAP_SYS_ADMIN))
+		return -EPERM;
+
+	spin_lock(&data_lock);
+	if (data->open) {
+		spin_unlock(&data_lock);
+		return -EBUSY;
+	}
+	data->open = 1;
+	spin_unlock(&data_lock);
+
+	if (data->state == STATE_NO_DATA &&
+	    !(data->log_buffer = vmalloc(ia64_sal_get_state_info_size(data->type)))) {
+		data->open = 0;
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+
+static int
+salinfo_log_release(struct inode *inode, struct file *file)
+{
+	struct salinfo_data *data = PDE_DATA(inode);
+
+	if (data->state == STATE_NO_DATA) {
+		vfree(data->log_buffer);
+		vfree(data->oemdata);
+		data->log_buffer = NULL;
+		data->oemdata = NULL;
+	}
+	spin_lock(&data_lock);
+	data->open = 0;
+	spin_unlock(&data_lock);
+	return 0;
+}
+
+static void
+call_on_cpu(int cpu, void (*fn)(void *), void *arg)
+{
+	cpumask_t save_cpus_allowed = current->cpus_allowed;
+	set_cpus_allowed_ptr(current, cpumask_of(cpu));
+	(*fn)(arg);
+	set_cpus_allowed_ptr(current, &save_cpus_allowed);
+}
+
+static void
+salinfo_log_read_cpu(void *context)
+{
+	struct salinfo_data *data = context;
+	sal_log_record_header_t *rh;
+	data->log_size = ia64_sal_get_state_info(data->type, (u64 *) data->log_buffer);
+	rh = (sal_log_record_header_t *)(data->log_buffer);
+	/* Clear corrected errors as they are read from SAL */
+	if (rh->severity == sal_log_severity_corrected)
+		ia64_sal_clear_state_info(data->type);
+}
+
+static void
+salinfo_log_new_read(int cpu, struct salinfo_data *data)
+{
+	struct salinfo_data_saved *data_saved;
+	unsigned long flags;
+	int i;
+	int saved_size = ARRAY_SIZE(data->data_saved);
+
+	data->saved_num = 0;
+	spin_lock_irqsave(&data_saved_lock, flags);
+retry:
+	for (i = 0, data_saved = data->data_saved; i < saved_size; ++i, ++data_saved) {
+		if (data_saved->buffer && data_saved->cpu == cpu) {
+			sal_log_record_header_t *rh = (sal_log_record_header_t *)(data_saved->buffer);
+			data->log_size = data_saved->size;
+			memcpy(data->log_buffer, rh, data->log_size);
+			barrier();	/* id check must not be moved */
+			if (rh->id == data_saved->id) {
+				data->saved_num = i+1;
+				break;
+			}
+			/* saved record changed by mca.c since interrupt, discard it */
+			shift1_data_saved(data, i);
+			goto retry;
+		}
+	}
+	spin_unlock_irqrestore(&data_saved_lock, flags);
+
+	if (!data->saved_num)
+		call_on_cpu(cpu, salinfo_log_read_cpu, data);
+	if (!data->log_size) {
+		data->state = STATE_NO_DATA;
+		cpu_clear(cpu, data->cpu_event);
+	} else {
+		data->state = STATE_LOG_RECORD;
+	}
+}
+
+static ssize_t
+salinfo_log_read(struct file *file, char __user *buffer, size_t count, loff_t *ppos)
+{
+	struct salinfo_data *data = PDE_DATA(file_inode(file));
+	u8 *buf;
+	u64 bufsize;
+
+	if (data->state == STATE_LOG_RECORD) {
+		buf = data->log_buffer;
+		bufsize = data->log_size;
+	} else if (data->state == STATE_OEMDATA) {
+		buf = data->oemdata;
+		bufsize = data->oemdata_size;
+	} else {
+		buf = NULL;
+		bufsize = 0;
+	}
+	return simple_read_from_buffer(buffer, count, ppos, buf, bufsize);
+}
+
+static void
+salinfo_log_clear_cpu(void *context)
+{
+	struct salinfo_data *data = context;
+	ia64_sal_clear_state_info(data->type);
+}
+
+static int
+salinfo_log_clear(struct salinfo_data *data, int cpu)
+{
+	sal_log_record_header_t *rh;
+	unsigned long flags;
+	spin_lock_irqsave(&data_saved_lock, flags);
+	data->state = STATE_NO_DATA;
+	if (!cpu_isset(cpu, data->cpu_event)) {
+		spin_unlock_irqrestore(&data_saved_lock, flags);
+		return 0;
+	}
+	cpu_clear(cpu, data->cpu_event);
+	if (data->saved_num) {
+		shift1_data_saved(data, data->saved_num - 1);
+		data->saved_num = 0;
+	}
+	spin_unlock_irqrestore(&data_saved_lock, flags);
+	rh = (sal_log_record_header_t *)(data->log_buffer);
+	/* Corrected errors have already been cleared from SAL */
+	if (rh->severity != sal_log_severity_corrected)
+		call_on_cpu(cpu, salinfo_log_clear_cpu, data);
+	/* clearing a record may make a new record visible */
+	salinfo_log_new_read(cpu, data);
+	if (data->state == STATE_LOG_RECORD) {
+		spin_lock_irqsave(&data_saved_lock, flags);
+		cpu_set(cpu, data->cpu_event);
+		salinfo_work_to_do(data);
+		spin_unlock_irqrestore(&data_saved_lock, flags);
+	}
+	return 0;
+}
+
+static ssize_t
+salinfo_log_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
+{
+	struct salinfo_data *data = PDE_DATA(file_inode(file));
+	char cmd[32];
+	size_t size;
+	u32 offset;
+	int cpu;
+
+	size = sizeof(cmd);
+	if (count < size)
+		size = count;
+	if (copy_from_user(cmd, buffer, size))
+		return -EFAULT;
+
+	if (sscanf(cmd, "read %d", &cpu) == 1) {
+		salinfo_log_new_read(cpu, data);
+	} else if (sscanf(cmd, "clear %d", &cpu) == 1) {
+		int ret;
+		if ((ret = salinfo_log_clear(data, cpu)))
+			count = ret;
+	} else if (sscanf(cmd, "oemdata %d %d", &cpu, &offset) == 2) {
+		if (data->state != STATE_LOG_RECORD && data->state != STATE_OEMDATA)
+			return -EINVAL;
+		if (offset > data->log_size - sizeof(efi_guid_t))
+			return -EINVAL;
+		data->state = STATE_OEMDATA;
+		if (salinfo_platform_oemdata) {
+			struct salinfo_platform_oemdata_parms parms = {
+				.efi_guid = data->log_buffer + offset,
+				.oemdata = &data->oemdata,
+				.oemdata_size = &data->oemdata_size
+			};
+			call_on_cpu(cpu, salinfo_platform_oemdata_cpu, &parms);
+			if (parms.ret)
+				count = parms.ret;
+		} else
+			data->oemdata_size = 0;
+	} else
+		return -EINVAL;
+
+	return count;
+}
+
+static const struct file_operations salinfo_data_fops = {
+	.open    = salinfo_log_open,
+	.release = salinfo_log_release,
+	.read    = salinfo_log_read,
+	.write   = salinfo_log_write,
+	.llseek  = default_llseek,
+};
+
+static int
+salinfo_cpu_callback(struct notifier_block *nb, unsigned long action, void *hcpu)
+{
+	unsigned int i, cpu = (unsigned long)hcpu;
+	unsigned long flags;
+	struct salinfo_data *data;
+	switch (action) {
+	case CPU_ONLINE:
+	case CPU_ONLINE_FROZEN:
+		spin_lock_irqsave(&data_saved_lock, flags);
+		for (i = 0, data = salinfo_data;
+		     i < ARRAY_SIZE(salinfo_data);
+		     ++i, ++data) {
+			cpu_set(cpu, data->cpu_event);
+			salinfo_work_to_do(data);
+		}
+		spin_unlock_irqrestore(&data_saved_lock, flags);
+		break;
+	case CPU_DEAD:
+	case CPU_DEAD_FROZEN:
+		spin_lock_irqsave(&data_saved_lock, flags);
+		for (i = 0, data = salinfo_data;
+		     i < ARRAY_SIZE(salinfo_data);
+		     ++i, ++data) {
+			struct salinfo_data_saved *data_saved;
+			int j;
+			for (j = ARRAY_SIZE(data->data_saved) - 1, data_saved = data->data_saved + j;
+			     j >= 0;
+			     --j, --data_saved) {
+				if (data_saved->buffer && data_saved->cpu == cpu) {
+					shift1_data_saved(data, j);
+				}
+			}
+			cpu_clear(cpu, data->cpu_event);
+		}
+		spin_unlock_irqrestore(&data_saved_lock, flags);
+		break;
+	}
+	return NOTIFY_OK;
+}
+
+static struct notifier_block salinfo_cpu_notifier =
+{
+	.notifier_call = salinfo_cpu_callback,
+	.priority = 0,
+};
+
+static int __init
+salinfo_init(void)
+{
+	struct proc_dir_entry *salinfo_dir; /* /proc/sal dir entry */
+	struct proc_dir_entry **sdir = salinfo_proc_entries; /* keeps track of every entry */
+	struct proc_dir_entry *dir, *entry;
+	struct salinfo_data *data;
+	int i, j;
+
+	salinfo_dir = proc_mkdir("sal", NULL);
+	if (!salinfo_dir)
+		return 0;
+
+	for (i=0; i < NR_SALINFO_ENTRIES; i++) {
+		/* pass the feature bit in question as misc data */
+		*sdir++ = proc_create_data(salinfo_entries[i].name, 0, salinfo_dir,
+					   &proc_salinfo_fops,
+					   (void *)salinfo_entries[i].feature);
+	}
+
+	cpu_notifier_register_begin();
+
+	for (i = 0; i < ARRAY_SIZE(salinfo_log_name); i++) {
+		data = salinfo_data + i;
+		data->type = i;
+		sema_init(&data->mutex, 1);
+		dir = proc_mkdir(salinfo_log_name[i], salinfo_dir);
+		if (!dir)
+			continue;
+
+		entry = proc_create_data("event", S_IRUSR, dir,
+					 &salinfo_event_fops, data);
+		if (!entry)
+			continue;
+		*sdir++ = entry;
+
+		entry = proc_create_data("data", S_IRUSR | S_IWUSR, dir,
+					 &salinfo_data_fops, data);
+		if (!entry)
+			continue;
+		*sdir++ = entry;
+
+		/* we missed any events before now */
+		for_each_online_cpu(j)
+			cpu_set(j, data->cpu_event);
+
+		*sdir++ = dir;
+	}
+
+	*sdir++ = salinfo_dir;
+
+	init_timer(&salinfo_timer);
+	salinfo_timer.expires = jiffies + SALINFO_TIMER_DELAY;
+	salinfo_timer.function = &salinfo_timeout;
+	add_timer(&salinfo_timer);
+
+	__register_hotcpu_notifier(&salinfo_cpu_notifier);
+
+	cpu_notifier_register_done();
+
+	return 0;
+}
+
+/*
+ * 'data' contains an integer that corresponds to the feature we're
+ * testing
+ */
+static int proc_salinfo_show(struct seq_file *m, void *v)
+{
+	unsigned long data = (unsigned long)v;
+	seq_puts(m, (sal_platform_features & data) ? "1\n" : "0\n");
+	return 0;
+}
+
+static int proc_salinfo_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, proc_salinfo_show, PDE_DATA(inode));
+}
+
+static const struct file_operations proc_salinfo_fops = {
+	.open		= proc_salinfo_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= single_release,
+};
+
+module_init(salinfo_init);