PM: Separate suspend to RAM functionality from core
Rafael J. Wysocki [Tue, 9 Jun 2009 23:27:12 +0000 (01:27 +0200)]
Move the suspend to RAM and standby code from kernel/power/main.c
to two separate files, kernel/power/suspend.c containing the basic
functions and kernel/power/suspend_test.c containing the automatic
suspend test facility based on the RTC clock alarm.

There are no changes in functionality related to these modifications.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>

kernel/power/Makefile
kernel/power/main.c
kernel/power/power.h
kernel/power/suspend.c [new file with mode: 0644]
kernel/power/suspend_test.c [new file with mode: 0644]

index 720ea4f..c4baf1b 100644 (file)
@@ -6,6 +6,8 @@ endif
 obj-$(CONFIG_PM)               += main.o
 obj-$(CONFIG_PM_SLEEP)         += console.o
 obj-$(CONFIG_FREEZER)          += process.o
+obj-$(CONFIG_SUSPEND)          += suspend.o
+obj-$(CONFIG_PM_TEST_SUSPEND)  += suspend_test.o
 obj-$(CONFIG_HIBERNATION)      += swsusp.o disk.o snapshot.o swap.o user.o
 
 obj-$(CONFIG_MAGIC_SYSRQ)      += poweroff.o
index 2a19f34..f710e36 100644 (file)
@@ -8,20 +8,9 @@
  *
  */
 
-#include <linux/module.h>
-#include <linux/suspend.h>
 #include <linux/kobject.h>
 #include <linux/string.h>
-#include <linux/delay.h>
-#include <linux/errno.h>
-#include <linux/kmod.h>
-#include <linux/init.h>
-#include <linux/console.h>
-#include <linux/cpu.h>
 #include <linux/resume-trace.h>
-#include <linux/freezer.h>
-#include <linux/vmstat.h>
-#include <linux/syscalls.h>
 
 #include "power.h"
 
@@ -119,355 +108,6 @@ power_attr(pm_test);
 
 #endif /* CONFIG_PM_SLEEP */
 
-#ifdef CONFIG_SUSPEND
-
-static int suspend_test(int level)
-{
-#ifdef CONFIG_PM_DEBUG
-       if (pm_test_level == level) {
-               printk(KERN_INFO "suspend debug: Waiting for 5 seconds.\n");
-               mdelay(5000);
-               return 1;
-       }
-#endif /* !CONFIG_PM_DEBUG */
-       return 0;
-}
-
-#ifdef CONFIG_PM_TEST_SUSPEND
-
-/*
- * We test the system suspend code by setting an RTC wakealarm a short
- * time in the future, then suspending.  Suspending the devices won't
- * normally take long ... some systems only need a few milliseconds.
- *
- * The time it takes is system-specific though, so when we test this
- * during system bootup we allow a LOT of time.
- */
-#define TEST_SUSPEND_SECONDS   5
-
-static unsigned long suspend_test_start_time;
-
-static void suspend_test_start(void)
-{
-       /* FIXME Use better timebase than "jiffies", ideally a clocksource.
-        * What we want is a hardware counter that will work correctly even
-        * during the irqs-are-off stages of the suspend/resume cycle...
-        */
-       suspend_test_start_time = jiffies;
-}
-
-static void suspend_test_finish(const char *label)
-{
-       long nj = jiffies - suspend_test_start_time;
-       unsigned msec;
-
-       msec = jiffies_to_msecs(abs(nj));
-       pr_info("PM: %s took %d.%03d seconds\n", label,
-                       msec / 1000, msec % 1000);
-
-       /* Warning on suspend means the RTC alarm period needs to be
-        * larger -- the system was sooo slooowwww to suspend that the
-        * alarm (should have) fired before the system went to sleep!
-        *
-        * Warning on either suspend or resume also means the system
-        * has some performance issues.  The stack dump of a WARN_ON
-        * is more likely to get the right attention than a printk...
-        */
-       WARN(msec > (TEST_SUSPEND_SECONDS * 1000), "Component: %s\n", label);
-}
-
-#else
-
-static void suspend_test_start(void)
-{
-}
-
-static void suspend_test_finish(const char *label)
-{
-}
-
-#endif
-
-static struct platform_suspend_ops *suspend_ops;
-
-/**
- *     suspend_set_ops - Set the global suspend method table.
- *     @ops:   Pointer to ops structure.
- */
-
-void suspend_set_ops(struct platform_suspend_ops *ops)
-{
-       mutex_lock(&pm_mutex);
-       suspend_ops = ops;
-       mutex_unlock(&pm_mutex);
-}
-
-/**
- * suspend_valid_only_mem - generic memory-only valid callback
- *
- * Platform drivers that implement mem suspend only and only need
- * to check for that in their .valid callback can use this instead
- * of rolling their own .valid callback.
- */
-int suspend_valid_only_mem(suspend_state_t state)
-{
-       return state == PM_SUSPEND_MEM;
-}
-
-/**
- *     suspend_prepare - Do prep work before entering low-power state.
- *
- *     This is common code that is called for each state that we're entering.
- *     Run suspend notifiers, allocate a console and stop all processes.
- */
-static int suspend_prepare(void)
-{
-       int error;
-
-       if (!suspend_ops || !suspend_ops->enter)
-               return -EPERM;
-
-       pm_prepare_console();
-
-       error = pm_notifier_call_chain(PM_SUSPEND_PREPARE);
-       if (error)
-               goto Finish;
-
-       error = usermodehelper_disable();
-       if (error)
-               goto Finish;
-
-       error = suspend_freeze_processes();
-       if (!error)
-               return 0;
-
-       suspend_thaw_processes();
-       usermodehelper_enable();
- Finish:
-       pm_notifier_call_chain(PM_POST_SUSPEND);
-       pm_restore_console();
-       return error;
-}
-
-/* default implementation */
-void __attribute__ ((weak)) arch_suspend_disable_irqs(void)
-{
-       local_irq_disable();
-}
-
-/* default implementation */
-void __attribute__ ((weak)) arch_suspend_enable_irqs(void)
-{
-       local_irq_enable();
-}
-
-/**
- *     suspend_enter - enter the desired system sleep state.
- *     @state:         state to enter
- *
- *     This function should be called after devices have been suspended.
- */
-static int suspend_enter(suspend_state_t state)
-{
-       int error;
-
-       if (suspend_ops->prepare) {
-               error = suspend_ops->prepare();
-               if (error)
-                       return error;
-       }
-
-       error = dpm_suspend_noirq(PMSG_SUSPEND);
-       if (error) {
-               printk(KERN_ERR "PM: Some devices failed to power down\n");
-               goto Platfrom_finish;
-       }
-
-       if (suspend_ops->prepare_late) {
-               error = suspend_ops->prepare_late();
-               if (error)
-                       goto Power_up_devices;
-       }
-
-       if (suspend_test(TEST_PLATFORM))
-               goto Platform_wake;
-
-       error = disable_nonboot_cpus();
-       if (error || suspend_test(TEST_CPUS))
-               goto Enable_cpus;
-
-       arch_suspend_disable_irqs();
-       BUG_ON(!irqs_disabled());
-
-       error = sysdev_suspend(PMSG_SUSPEND);
-       if (!error) {
-               if (!suspend_test(TEST_CORE))
-                       error = suspend_ops->enter(state);
-               sysdev_resume();
-       }
-
-       arch_suspend_enable_irqs();
-       BUG_ON(irqs_disabled());
-
- Enable_cpus:
-       enable_nonboot_cpus();
-
- Platform_wake:
-       if (suspend_ops->wake)
-               suspend_ops->wake();
-
- Power_up_devices:
-       dpm_resume_noirq(PMSG_RESUME);
-
- Platfrom_finish:
-       if (suspend_ops->finish)
-               suspend_ops->finish();
-
-       return error;
-}
-
-/**
- *     suspend_devices_and_enter - suspend devices and enter the desired system
- *                                 sleep state.
- *     @state:           state to enter
- */
-int suspend_devices_and_enter(suspend_state_t state)
-{
-       int error;
-
-       if (!suspend_ops)
-               return -ENOSYS;
-
-       if (suspend_ops->begin) {
-               error = suspend_ops->begin(state);
-               if (error)
-                       goto Close;
-       }
-       suspend_console();
-       suspend_test_start();
-       error = dpm_suspend_start(PMSG_SUSPEND);
-       if (error) {
-               printk(KERN_ERR "PM: Some devices failed to suspend\n");
-               goto Recover_platform;
-       }
-       suspend_test_finish("suspend devices");
-       if (suspend_test(TEST_DEVICES))
-               goto Recover_platform;
-
-       suspend_enter(state);
-
- Resume_devices:
-       suspend_test_start();
-       dpm_resume_end(PMSG_RESUME);
-       suspend_test_finish("resume devices");
-       resume_console();
- Close:
-       if (suspend_ops->end)
-               suspend_ops->end();
-       return error;
-
- Recover_platform:
-       if (suspend_ops->recover)
-               suspend_ops->recover();
-       goto Resume_devices;
-}
-
-/**
- *     suspend_finish - Do final work before exiting suspend sequence.
- *
- *     Call platform code to clean up, restart processes, and free the 
- *     console that we've allocated. This is not called for suspend-to-disk.
- */
-static void suspend_finish(void)
-{
-       suspend_thaw_processes();
-       usermodehelper_enable();
-       pm_notifier_call_chain(PM_POST_SUSPEND);
-       pm_restore_console();
-}
-
-
-
-
-static const char * const pm_states[PM_SUSPEND_MAX] = {
-       [PM_SUSPEND_STANDBY]    = "standby",
-       [PM_SUSPEND_MEM]        = "mem",
-};
-
-static inline int valid_state(suspend_state_t state)
-{
-       /* All states need lowlevel support and need to be valid
-        * to the lowlevel implementation, no valid callback
-        * implies that none are valid. */
-       if (!suspend_ops || !suspend_ops->valid || !suspend_ops->valid(state))
-               return 0;
-       return 1;
-}
-
-
-/**
- *     enter_state - Do common work of entering low-power state.
- *     @state:         pm_state structure for state we're entering.
- *
- *     Make sure we're the only ones trying to enter a sleep state. Fail
- *     if someone has beat us to it, since we don't want anything weird to
- *     happen when we wake up.
- *     Then, do the setup for suspend, enter the state, and cleaup (after
- *     we've woken up).
- */
-static int enter_state(suspend_state_t state)
-{
-       int error;
-
-       if (!valid_state(state))
-               return -ENODEV;
-
-       if (!mutex_trylock(&pm_mutex))
-               return -EBUSY;
-
-       printk(KERN_INFO "PM: Syncing filesystems ... ");
-       sys_sync();
-       printk("done.\n");
-
-       pr_debug("PM: Preparing system for %s sleep\n", pm_states[state]);
-       error = suspend_prepare();
-       if (error)
-               goto Unlock;
-
-       if (suspend_test(TEST_FREEZER))
-               goto Finish;
-
-       pr_debug("PM: Entering %s sleep\n", pm_states[state]);
-       error = suspend_devices_and_enter(state);
-
- Finish:
-       pr_debug("PM: Finishing wakeup.\n");
-       suspend_finish();
- Unlock:
-       mutex_unlock(&pm_mutex);
-       return error;
-}
-
-
-/**
- *     pm_suspend - Externally visible function for suspending system.
- *     @state:         Enumerated value of state to enter.
- *
- *     Determine whether or not value is within range, get state 
- *     structure, and enter (above).
- */
-
-int pm_suspend(suspend_state_t state)
-{
-       if (state > PM_SUSPEND_ON && state <= PM_SUSPEND_MAX)
-               return enter_state(state);
-       return -EINVAL;
-}
-
-EXPORT_SYMBOL(pm_suspend);
-
-#endif /* CONFIG_SUSPEND */
-
 struct kobject *power_kobj;
 
 /**
@@ -480,7 +120,6 @@ struct kobject *power_kobj;
  *     store() accepts one of those strings, translates it into the 
  *     proper enumerated value, and initiates a suspend transition.
  */
-
 static ssize_t state_show(struct kobject *kobj, struct kobj_attribute *attr,
                          char *buf)
 {
@@ -578,7 +217,6 @@ static struct attribute_group attr_group = {
        .attrs = g,
 };
 
-
 static int __init pm_init(void)
 {
        power_kobj = kobject_create_and_add("power", NULL);
@@ -588,144 +226,3 @@ static int __init pm_init(void)
 }
 
 core_initcall(pm_init);
-
-
-#ifdef CONFIG_PM_TEST_SUSPEND
-
-#include <linux/rtc.h>
-
-/*
- * To test system suspend, we need a hands-off mechanism to resume the
- * system.  RTCs wake alarms are a common self-contained mechanism.
- */
-
-static void __init test_wakealarm(struct rtc_device *rtc, suspend_state_t state)
-{
-       static char err_readtime[] __initdata =
-               KERN_ERR "PM: can't read %s time, err %d\n";
-       static char err_wakealarm [] __initdata =
-               KERN_ERR "PM: can't set %s wakealarm, err %d\n";
-       static char err_suspend[] __initdata =
-               KERN_ERR "PM: suspend test failed, error %d\n";
-       static char info_test[] __initdata =
-               KERN_INFO "PM: test RTC wakeup from '%s' suspend\n";
-
-       unsigned long           now;
-       struct rtc_wkalrm       alm;
-       int                     status;
-
-       /* this may fail if the RTC hasn't been initialized */
-       status = rtc_read_time(rtc, &alm.time);
-       if (status < 0) {
-               printk(err_readtime, dev_name(&rtc->dev), status);
-               return;
-       }
-       rtc_tm_to_time(&alm.time, &now);
-
-       memset(&alm, 0, sizeof alm);
-       rtc_time_to_tm(now + TEST_SUSPEND_SECONDS, &alm.time);
-       alm.enabled = true;
-
-       status = rtc_set_alarm(rtc, &alm);
-       if (status < 0) {
-               printk(err_wakealarm, dev_name(&rtc->dev), status);
-               return;
-       }
-
-       if (state == PM_SUSPEND_MEM) {
-               printk(info_test, pm_states[state]);
-               status = pm_suspend(state);
-               if (status == -ENODEV)
-                       state = PM_SUSPEND_STANDBY;
-       }
-       if (state == PM_SUSPEND_STANDBY) {
-               printk(info_test, pm_states[state]);
-               status = pm_suspend(state);
-       }
-       if (status < 0)
-               printk(err_suspend, status);
-
-       /* Some platforms can't detect that the alarm triggered the
-        * wakeup, or (accordingly) disable it after it afterwards.
-        * It's supposed to give oneshot behavior; cope.
-        */
-       alm.enabled = false;
-       rtc_set_alarm(rtc, &alm);
-}
-
-static int __init has_wakealarm(struct device *dev, void *name_ptr)
-{
-       struct rtc_device *candidate = to_rtc_device(dev);
-
-       if (!candidate->ops->set_alarm)
-               return 0;
-       if (!device_may_wakeup(candidate->dev.parent))
-               return 0;
-
-       *(const char **)name_ptr = dev_name(dev);
-       return 1;
-}
-
-/*
- * Kernel options like "test_suspend=mem" force suspend/resume sanity tests
- * at startup time.  They're normally disabled, for faster boot and because
- * we can't know which states really work on this particular system.
- */
-static suspend_state_t test_state __initdata = PM_SUSPEND_ON;
-
-static char warn_bad_state[] __initdata =
-       KERN_WARNING "PM: can't test '%s' suspend state\n";
-
-static int __init setup_test_suspend(char *value)
-{
-       unsigned i;
-
-       /* "=mem" ==> "mem" */
-       value++;
-       for (i = 0; i < PM_SUSPEND_MAX; i++) {
-               if (!pm_states[i])
-                       continue;
-               if (strcmp(pm_states[i], value) != 0)
-                       continue;
-               test_state = (__force suspend_state_t) i;
-               return 0;
-       }
-       printk(warn_bad_state, value);
-       return 0;
-}
-__setup("test_suspend", setup_test_suspend);
-
-static int __init test_suspend(void)
-{
-       static char             warn_no_rtc[] __initdata =
-               KERN_WARNING "PM: no wakealarm-capable RTC driver is ready\n";
-
-       char                    *pony = NULL;
-       struct rtc_device       *rtc = NULL;
-
-       /* PM is initialized by now; is that state testable? */
-       if (test_state == PM_SUSPEND_ON)
-               goto done;
-       if (!valid_state(test_state)) {
-               printk(warn_bad_state, pm_states[test_state]);
-               goto done;
-       }
-
-       /* RTCs have initialized by now too ... can we use one? */
-       class_find_device(rtc_class, NULL, &pony, has_wakealarm);
-       if (pony)
-               rtc = rtc_class_open(pony);
-       if (!rtc) {
-               printk(warn_no_rtc);
-               goto done;
-       }
-
-       /* go for it */
-       test_wakealarm(rtc, test_state);
-       rtc_class_close(rtc);
-done:
-       return 0;
-}
-late_initcall(test_suspend);
-
-#endif /* CONFIG_PM_TEST_SUSPEND */
index ec4dbdf..2bd98d9 100644 (file)
@@ -160,15 +160,30 @@ extern void swsusp_show_speed(struct timeval *, struct timeval *,
                                unsigned int, char *);
 
 #ifdef CONFIG_SUSPEND
-/* kernel/power/main.c */
+/* kernel/power/suspend.c */
+extern const char *const pm_states[];
+
+extern bool valid_state(suspend_state_t state);
 extern int suspend_devices_and_enter(suspend_state_t state);
+extern int enter_state(suspend_state_t state);
 #else /* !CONFIG_SUSPEND */
 static inline int suspend_devices_and_enter(suspend_state_t state)
 {
        return -ENOSYS;
 }
+static inline int enter_state(suspend_state_t state) { return -ENOSYS; }
+static inline bool valid_state(suspend_state_t state) { return false; }
 #endif /* !CONFIG_SUSPEND */
 
+#ifdef CONFIG_PM_TEST_SUSPEND
+/* kernel/power/suspend_test.c */
+extern void suspend_test_start(void);
+extern void suspend_test_finish(const char *label);
+#else /* !CONFIG_PM_TEST_SUSPEND */
+static inline void suspend_test_start(void) {}
+static inline void suspend_test_finish(const char *label) {}
+#endif /* !CONFIG_PM_TEST_SUSPEND */
+
 #ifdef CONFIG_PM_SLEEP
 /* kernel/power/main.c */
 extern int pm_notifier_call_chain(unsigned long val);
diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c
new file mode 100644 (file)
index 0000000..6f10dfc
--- /dev/null
@@ -0,0 +1,300 @@
+/*
+ * kernel/power/suspend.c - Suspend to RAM and standby functionality.
+ *
+ * Copyright (c) 2003 Patrick Mochel
+ * Copyright (c) 2003 Open Source Development Lab
+ * Copyright (c) 2009 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc.
+ *
+ * This file is released under the GPLv2.
+ */
+
+#include <linux/string.h>
+#include <linux/delay.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/console.h>
+#include <linux/cpu.h>
+#include <linux/syscalls.h>
+
+#include "power.h"
+
+const char *const pm_states[PM_SUSPEND_MAX] = {
+       [PM_SUSPEND_STANDBY]    = "standby",
+       [PM_SUSPEND_MEM]        = "mem",
+};
+
+static struct platform_suspend_ops *suspend_ops;
+
+/**
+ *     suspend_set_ops - Set the global suspend method table.
+ *     @ops:   Pointer to ops structure.
+ */
+void suspend_set_ops(struct platform_suspend_ops *ops)
+{
+       mutex_lock(&pm_mutex);
+       suspend_ops = ops;
+       mutex_unlock(&pm_mutex);
+}
+
+bool valid_state(suspend_state_t state)
+{
+       /*
+        * All states need lowlevel support and need to be valid to the lowlevel
+        * implementation, no valid callback implies that none are valid.
+        */
+       return suspend_ops && suspend_ops->valid && suspend_ops->valid(state);
+}
+
+/**
+ * suspend_valid_only_mem - generic memory-only valid callback
+ *
+ * Platform drivers that implement mem suspend only and only need
+ * to check for that in their .valid callback can use this instead
+ * of rolling their own .valid callback.
+ */
+int suspend_valid_only_mem(suspend_state_t state)
+{
+       return state == PM_SUSPEND_MEM;
+}
+
+static int suspend_test(int level)
+{
+#ifdef CONFIG_PM_DEBUG
+       if (pm_test_level == level) {
+               printk(KERN_INFO "suspend debug: Waiting for 5 seconds.\n");
+               mdelay(5000);
+               return 1;
+       }
+#endif /* !CONFIG_PM_DEBUG */
+       return 0;
+}
+
+/**
+ *     suspend_prepare - Do prep work before entering low-power state.
+ *
+ *     This is common code that is called for each state that we're entering.
+ *     Run suspend notifiers, allocate a console and stop all processes.
+ */
+static int suspend_prepare(void)
+{
+       int error;
+
+       if (!suspend_ops || !suspend_ops->enter)
+               return -EPERM;
+
+       pm_prepare_console();
+
+       error = pm_notifier_call_chain(PM_SUSPEND_PREPARE);
+       if (error)
+               goto Finish;
+
+       error = usermodehelper_disable();
+       if (error)
+               goto Finish;
+
+       error = suspend_freeze_processes();
+       if (!error)
+               return 0;
+
+       suspend_thaw_processes();
+       usermodehelper_enable();
+ Finish:
+       pm_notifier_call_chain(PM_POST_SUSPEND);
+       pm_restore_console();
+       return error;
+}
+
+/* default implementation */
+void __attribute__ ((weak)) arch_suspend_disable_irqs(void)
+{
+       local_irq_disable();
+}
+
+/* default implementation */
+void __attribute__ ((weak)) arch_suspend_enable_irqs(void)
+{
+       local_irq_enable();
+}
+
+/**
+ *     suspend_enter - enter the desired system sleep state.
+ *     @state:         state to enter
+ *
+ *     This function should be called after devices have been suspended.
+ */
+static int suspend_enter(suspend_state_t state)
+{
+       int error;
+
+       if (suspend_ops->prepare) {
+               error = suspend_ops->prepare();
+               if (error)
+                       return error;
+       }
+
+       error = dpm_suspend_noirq(PMSG_SUSPEND);
+       if (error) {
+               printk(KERN_ERR "PM: Some devices failed to power down\n");
+               goto Platfrom_finish;
+       }
+
+       if (suspend_ops->prepare_late) {
+               error = suspend_ops->prepare_late();
+               if (error)
+                       goto Power_up_devices;
+       }
+
+       if (suspend_test(TEST_PLATFORM))
+               goto Platform_wake;
+
+       error = disable_nonboot_cpus();
+       if (error || suspend_test(TEST_CPUS))
+               goto Enable_cpus;
+
+       arch_suspend_disable_irqs();
+       BUG_ON(!irqs_disabled());
+
+       error = sysdev_suspend(PMSG_SUSPEND);
+       if (!error) {
+               if (!suspend_test(TEST_CORE))
+                       error = suspend_ops->enter(state);
+               sysdev_resume();
+       }
+
+       arch_suspend_enable_irqs();
+       BUG_ON(irqs_disabled());
+
+ Enable_cpus:
+       enable_nonboot_cpus();
+
+ Platform_wake:
+       if (suspend_ops->wake)
+               suspend_ops->wake();
+
+ Power_up_devices:
+       dpm_resume_noirq(PMSG_RESUME);
+
+ Platfrom_finish:
+       if (suspend_ops->finish)
+               suspend_ops->finish();
+
+       return error;
+}
+
+/**
+ *     suspend_devices_and_enter - suspend devices and enter the desired system
+ *                                 sleep state.
+ *     @state:           state to enter
+ */
+int suspend_devices_and_enter(suspend_state_t state)
+{
+       int error;
+
+       if (!suspend_ops)
+               return -ENOSYS;
+
+       if (suspend_ops->begin) {
+               error = suspend_ops->begin(state);
+               if (error)
+                       goto Close;
+       }
+       suspend_console();
+       suspend_test_start();
+       error = dpm_suspend_start(PMSG_SUSPEND);
+       if (error) {
+               printk(KERN_ERR "PM: Some devices failed to suspend\n");
+               goto Recover_platform;
+       }
+       suspend_test_finish("suspend devices");
+       if (suspend_test(TEST_DEVICES))
+               goto Recover_platform;
+
+       suspend_enter(state);
+
+ Resume_devices:
+       suspend_test_start();
+       dpm_resume_end(PMSG_RESUME);
+       suspend_test_finish("resume devices");
+       resume_console();
+ Close:
+       if (suspend_ops->end)
+               suspend_ops->end();
+       return error;
+
+ Recover_platform:
+       if (suspend_ops->recover)
+               suspend_ops->recover();
+       goto Resume_devices;
+}
+
+/**
+ *     suspend_finish - Do final work before exiting suspend sequence.
+ *
+ *     Call platform code to clean up, restart processes, and free the
+ *     console that we've allocated. This is not called for suspend-to-disk.
+ */
+static void suspend_finish(void)
+{
+       suspend_thaw_processes();
+       usermodehelper_enable();
+       pm_notifier_call_chain(PM_POST_SUSPEND);
+       pm_restore_console();
+}
+
+/**
+ *     enter_state - Do common work of entering low-power state.
+ *     @state:         pm_state structure for state we're entering.
+ *
+ *     Make sure we're the only ones trying to enter a sleep state. Fail
+ *     if someone has beat us to it, since we don't want anything weird to
+ *     happen when we wake up.
+ *     Then, do the setup for suspend, enter the state, and cleaup (after
+ *     we've woken up).
+ */
+int enter_state(suspend_state_t state)
+{
+       int error;
+
+       if (!valid_state(state))
+               return -ENODEV;
+
+       if (!mutex_trylock(&pm_mutex))
+               return -EBUSY;
+
+       printk(KERN_INFO "PM: Syncing filesystems ... ");
+       sys_sync();
+       printk("done.\n");
+
+       pr_debug("PM: Preparing system for %s sleep\n", pm_states[state]);
+       error = suspend_prepare();
+       if (error)
+               goto Unlock;
+
+       if (suspend_test(TEST_FREEZER))
+               goto Finish;
+
+       pr_debug("PM: Entering %s sleep\n", pm_states[state]);
+       error = suspend_devices_and_enter(state);
+
+ Finish:
+       pr_debug("PM: Finishing wakeup.\n");
+       suspend_finish();
+ Unlock:
+       mutex_unlock(&pm_mutex);
+       return error;
+}
+
+/**
+ *     pm_suspend - Externally visible function for suspending system.
+ *     @state:         Enumerated value of state to enter.
+ *
+ *     Determine whether or not value is within range, get state
+ *     structure, and enter (above).
+ */
+int pm_suspend(suspend_state_t state)
+{
+       if (state > PM_SUSPEND_ON && state <= PM_SUSPEND_MAX)
+               return enter_state(state);
+       return -EINVAL;
+}
+EXPORT_SYMBOL(pm_suspend);
diff --git a/kernel/power/suspend_test.c b/kernel/power/suspend_test.c
new file mode 100644 (file)
index 0000000..17d8bb1
--- /dev/null
@@ -0,0 +1,187 @@
+/*
+ * kernel/power/suspend_test.c - Suspend to RAM and standby test facility.
+ *
+ * Copyright (c) 2009 Pavel Machek <pavel@ucw.cz>
+ *
+ * This file is released under the GPLv2.
+ */
+
+#include <linux/init.h>
+#include <linux/rtc.h>
+
+#include "power.h"
+
+/*
+ * We test the system suspend code by setting an RTC wakealarm a short
+ * time in the future, then suspending.  Suspending the devices won't
+ * normally take long ... some systems only need a few milliseconds.
+ *
+ * The time it takes is system-specific though, so when we test this
+ * during system bootup we allow a LOT of time.
+ */
+#define TEST_SUSPEND_SECONDS   5
+
+static unsigned long suspend_test_start_time;
+
+void suspend_test_start(void)
+{
+       /* FIXME Use better timebase than "jiffies", ideally a clocksource.
+        * What we want is a hardware counter that will work correctly even
+        * during the irqs-are-off stages of the suspend/resume cycle...
+        */
+       suspend_test_start_time = jiffies;
+}
+
+void suspend_test_finish(const char *label)
+{
+       long nj = jiffies - suspend_test_start_time;
+       unsigned msec;
+
+       msec = jiffies_to_msecs(abs(nj));
+       pr_info("PM: %s took %d.%03d seconds\n", label,
+                       msec / 1000, msec % 1000);
+
+       /* Warning on suspend means the RTC alarm period needs to be
+        * larger -- the system was sooo slooowwww to suspend that the
+        * alarm (should have) fired before the system went to sleep!
+        *
+        * Warning on either suspend or resume also means the system
+        * has some performance issues.  The stack dump of a WARN_ON
+        * is more likely to get the right attention than a printk...
+        */
+       WARN(msec > (TEST_SUSPEND_SECONDS * 1000), "Component: %s\n", label);
+}
+
+/*
+ * To test system suspend, we need a hands-off mechanism to resume the
+ * system.  RTCs wake alarms are a common self-contained mechanism.
+ */
+
+static void __init test_wakealarm(struct rtc_device *rtc, suspend_state_t state)
+{
+       static char err_readtime[] __initdata =
+               KERN_ERR "PM: can't read %s time, err %d\n";
+       static char err_wakealarm [] __initdata =
+               KERN_ERR "PM: can't set %s wakealarm, err %d\n";
+       static char err_suspend[] __initdata =
+               KERN_ERR "PM: suspend test failed, error %d\n";
+       static char info_test[] __initdata =
+               KERN_INFO "PM: test RTC wakeup from '%s' suspend\n";
+
+       unsigned long           now;
+       struct rtc_wkalrm       alm;
+       int                     status;
+
+       /* this may fail if the RTC hasn't been initialized */
+       status = rtc_read_time(rtc, &alm.time);
+       if (status < 0) {
+               printk(err_readtime, dev_name(&rtc->dev), status);
+               return;
+       }
+       rtc_tm_to_time(&alm.time, &now);
+
+       memset(&alm, 0, sizeof alm);
+       rtc_time_to_tm(now + TEST_SUSPEND_SECONDS, &alm.time);
+       alm.enabled = true;
+
+       status = rtc_set_alarm(rtc, &alm);
+       if (status < 0) {
+               printk(err_wakealarm, dev_name(&rtc->dev), status);
+               return;
+       }
+
+       if (state == PM_SUSPEND_MEM) {
+               printk(info_test, pm_states[state]);
+               status = pm_suspend(state);
+               if (status == -ENODEV)
+                       state = PM_SUSPEND_STANDBY;
+       }
+       if (state == PM_SUSPEND_STANDBY) {
+               printk(info_test, pm_states[state]);
+               status = pm_suspend(state);
+       }
+       if (status < 0)
+               printk(err_suspend, status);
+
+       /* Some platforms can't detect that the alarm triggered the
+        * wakeup, or (accordingly) disable it after it afterwards.
+        * It's supposed to give oneshot behavior; cope.
+        */
+       alm.enabled = false;
+       rtc_set_alarm(rtc, &alm);
+}
+
+static int __init has_wakealarm(struct device *dev, void *name_ptr)
+{
+       struct rtc_device *candidate = to_rtc_device(dev);
+
+       if (!candidate->ops->set_alarm)
+               return 0;
+       if (!device_may_wakeup(candidate->dev.parent))
+               return 0;
+
+       *(const char **)name_ptr = dev_name(dev);
+       return 1;
+}
+
+/*
+ * Kernel options like "test_suspend=mem" force suspend/resume sanity tests
+ * at startup time.  They're normally disabled, for faster boot and because
+ * we can't know which states really work on this particular system.
+ */
+static suspend_state_t test_state __initdata = PM_SUSPEND_ON;
+
+static char warn_bad_state[] __initdata =
+       KERN_WARNING "PM: can't test '%s' suspend state\n";
+
+static int __init setup_test_suspend(char *value)
+{
+       unsigned i;
+
+       /* "=mem" ==> "mem" */
+       value++;
+       for (i = 0; i < PM_SUSPEND_MAX; i++) {
+               if (!pm_states[i])
+                       continue;
+               if (strcmp(pm_states[i], value) != 0)
+                       continue;
+               test_state = (__force suspend_state_t) i;
+               return 0;
+       }
+       printk(warn_bad_state, value);
+       return 0;
+}
+__setup("test_suspend", setup_test_suspend);
+
+static int __init test_suspend(void)
+{
+       static char             warn_no_rtc[] __initdata =
+               KERN_WARNING "PM: no wakealarm-capable RTC driver is ready\n";
+
+       char                    *pony = NULL;
+       struct rtc_device       *rtc = NULL;
+
+       /* PM is initialized by now; is that state testable? */
+       if (test_state == PM_SUSPEND_ON)
+               goto done;
+       if (!valid_state(test_state)) {
+               printk(warn_bad_state, pm_states[test_state]);
+               goto done;
+       }
+
+       /* RTCs have initialized by now too ... can we use one? */
+       class_find_device(rtc_class, NULL, &pony, has_wakealarm);
+       if (pony)
+               rtc = rtc_class_open(pony);
+       if (!rtc) {
+               printk(warn_no_rtc);
+               goto done;
+       }
+
+       /* go for it */
+       test_wakealarm(rtc, test_state);
+       rtc_class_close(rtc);
+done:
+       return 0;
+}
+late_initcall(test_suspend);