PM: Introduce core framework for run-time PM of I/O devices (rev. 17)
[linux-2.6.git] / kernel / power / main.c
index 2a46b6d..347d2cc 100644 (file)
  *
  */
 
-#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/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/workqueue.h>
 
 #include "power.h"
 
-BLOCKING_NOTIFIER_HEAD(pm_chain_head);
-
 DEFINE_MUTEX(pm_mutex);
 
-#ifdef CONFIG_SUSPEND
+unsigned int pm_flags;
+EXPORT_SYMBOL(pm_flags);
 
-/* This is just an arbitrary number */
-#define FREE_PAGE_NUMBER (100)
+#ifdef CONFIG_PM_SLEEP
 
-struct pm_ops *pm_ops;
+/* Routines for PM-transition notifications */
 
-/**
- *     pm_set_ops - Set the global power method table. 
- *     @ops:   Pointer to ops structure.
- */
+static BLOCKING_NOTIFIER_HEAD(pm_chain_head);
 
-void pm_set_ops(struct pm_ops * ops)
+int register_pm_notifier(struct notifier_block *nb)
 {
-       mutex_lock(&pm_mutex);
-       pm_ops = ops;
-       mutex_unlock(&pm_mutex);
+       return blocking_notifier_chain_register(&pm_chain_head, nb);
 }
+EXPORT_SYMBOL_GPL(register_pm_notifier);
 
-/**
- * pm_valid_only_mem - generic memory-only valid callback
- *
- * pm_ops 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 pm_valid_only_mem(suspend_state_t state)
+int unregister_pm_notifier(struct notifier_block *nb)
 {
-       return state == PM_SUSPEND_MEM;
+       return blocking_notifier_chain_unregister(&pm_chain_head, nb);
 }
+EXPORT_SYMBOL_GPL(unregister_pm_notifier);
 
-
-static inline void pm_finish(suspend_state_t state)
+int pm_notifier_call_chain(unsigned long val)
 {
-       if (pm_ops->finish)
-               pm_ops->finish(state);
+       return (blocking_notifier_call_chain(&pm_chain_head, val, NULL)
+                       == NOTIFY_BAD) ? -EINVAL : 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;
-       unsigned int free_pages;
-
-       if (!pm_ops || !pm_ops->enter)
-               return -EPERM;
-
-       error = pm_notifier_call_chain(PM_SUSPEND_PREPARE);
-       if (error)
-               goto Finish;
-
-       pm_prepare_console();
-
-       if (freeze_processes()) {
-               error = -EAGAIN;
-               goto Thaw;
-       }
-
-       free_pages = global_page_state(NR_FREE_PAGES);
-       if (free_pages < FREE_PAGE_NUMBER) {
-               pr_debug("PM: free some memory\n");
-               shrink_all_memory(FREE_PAGE_NUMBER - free_pages);
-               if (nr_free_pages() < FREE_PAGE_NUMBER) {
-                       error = -ENOMEM;
-                       printk(KERN_ERR "PM: No enough memory\n");
-               }
-       }
-       if (!error)
-               return 0;
-
- Thaw:
-       thaw_processes();
-       pm_restore_console();
- Finish:
-       pm_notifier_call_chain(PM_POST_SUSPEND);
-       return error;
-}
-
-/* default implementation */
-void __attribute__ ((weak)) arch_suspend_disable_irqs(void)
-{
-       local_irq_disable();
-}
+#ifdef CONFIG_PM_DEBUG
+int pm_test_level = TEST_NONE;
 
-/* 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 = 0;
-
-       arch_suspend_disable_irqs();
-       BUG_ON(!irqs_disabled());
-
-       if ((error = device_power_down(PMSG_SUSPEND))) {
-               printk(KERN_ERR "Some devices failed to power down\n");
-               goto Done;
-       }
-       error = pm_ops->enter(state);
-       device_power_up();
- Done:
-       arch_suspend_enable_irqs();
-       BUG_ON(irqs_disabled());
-       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 (!pm_ops)
-               return -ENOSYS;
-
-       if (pm_ops->set_target) {
-               error = pm_ops->set_target(state);
-               if (error)
-                       return error;
-       }
-       suspend_console();
-       error = device_suspend(PMSG_SUSPEND);
-       if (error) {
-               printk(KERN_ERR "Some devices failed to suspend\n");
-               goto Resume_console;
-       }
-       if (pm_ops->prepare) {
-               error = pm_ops->prepare(state);
-               if (error)
-                       goto Resume_devices;
-       }
-       error = disable_nonboot_cpus();
-       if (!error)
-               suspend_enter(state);
-
-       enable_nonboot_cpus();
-       pm_finish(state);
- Resume_devices:
-       device_resume();
- Resume_console:
-       resume_console();
-       return error;
-}
+static const char * const pm_tests[__TEST_AFTER_LAST] = {
+       [TEST_NONE] = "none",
+       [TEST_CORE] = "core",
+       [TEST_CPUS] = "processors",
+       [TEST_PLATFORM] = "platform",
+       [TEST_DEVICES] = "devices",
+       [TEST_FREEZER] = "freezer",
+};
 
-/**
- *     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)
+static ssize_t pm_test_show(struct kobject *kobj, struct kobj_attribute *attr,
+                               char *buf)
 {
-       thaw_processes();
-       pm_restore_console();
-       pm_notifier_call_chain(PM_POST_SUSPEND);
-}
-
-
-
+       char *s = buf;
+       int level;
+
+       for (level = TEST_FIRST; level <= TEST_MAX; level++)
+               if (pm_tests[level]) {
+                       if (level == pm_test_level)
+                               s += sprintf(s, "[%s] ", pm_tests[level]);
+                       else
+                               s += sprintf(s, "%s ", pm_tests[level]);
+               }
 
-static const char * const pm_states[PM_SUSPEND_MAX] = {
-       [PM_SUSPEND_STANDBY]    = "standby",
-       [PM_SUSPEND_MEM]        = "mem",
-};
+       if (s != buf)
+               /* convert the last space to a newline */
+               *(s-1) = '\n';
 
-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 (!pm_ops || !pm_ops->valid || !pm_ops->valid(state))
-               return 0;
-       return 1;
+       return (s - buf);
 }
 
-
-/**
- *     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)
+static ssize_t pm_test_store(struct kobject *kobj, struct kobj_attribute *attr,
+                               const char *buf, size_t n)
 {
-       int error;
+       const char * const *s;
+       int level;
+       char *p;
+       int len;
+       int error = -EINVAL;
 
-       if (!valid_state(state))
-               return -ENODEV;
-       if (!mutex_trylock(&pm_mutex))
-               return -EBUSY;
+       p = memchr(buf, '\n', n);
+       len = p ? p - buf : n;
 
-       pr_debug("PM: Preparing system for %s sleep\n", pm_states[state]);
-       if ((error = suspend_prepare()))
-               goto Unlock;
+       mutex_lock(&pm_mutex);
 
-       pr_debug("PM: Entering %s sleep\n", pm_states[state]);
-       error = suspend_devices_and_enter(state);
+       level = TEST_FIRST;
+       for (s = &pm_tests[level]; level <= TEST_MAX; s++, level++)
+               if (*s && len == strlen(*s) && !strncmp(buf, *s, len)) {
+                       pm_test_level = level;
+                       error = 0;
+                       break;
+               }
 
-       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;
+       return error ? error : n;
 }
 
-EXPORT_SYMBOL(pm_suspend);
+power_attr(pm_test);
+#endif /* CONFIG_PM_DEBUG */
 
-#endif /* CONFIG_SUSPEND */
-
-decl_subsys(power,NULL,NULL);
+#endif /* CONFIG_PM_SLEEP */
 
+struct kobject *power_kobj;
 
 /**
  *     state - control system power state.
@@ -286,8 +121,8 @@ decl_subsys(power,NULL,NULL);
  *     store() accepts one of those strings, translates it into the 
  *     proper enumerated value, and initiates a suspend transition.
  */
-
-static ssize_t state_show(struct kset *kset, char *buf)
+static ssize_t state_show(struct kobject *kobj, struct kobj_attribute *attr,
+                         char *buf)
 {
        char *s = buf;
 #ifdef CONFIG_SUSPEND
@@ -308,7 +143,8 @@ static ssize_t state_show(struct kset *kset, char *buf)
        return (s - buf);
 }
 
-static ssize_t state_store(struct kset *kset, const char *buf, size_t n)
+static ssize_t state_store(struct kobject *kobj, struct kobj_attribute *attr,
+                          const char *buf, size_t n)
 {
 #ifdef CONFIG_SUSPEND
        suspend_state_t state = PM_SUSPEND_STANDBY;
@@ -345,13 +181,15 @@ power_attr(state);
 #ifdef CONFIG_PM_TRACE
 int pm_trace_enabled;
 
-static ssize_t pm_trace_show(struct kset *kset, char *buf)
+static ssize_t pm_trace_show(struct kobject *kobj, struct kobj_attribute *attr,
+                            char *buf)
 {
        return sprintf(buf, "%d\n", pm_trace_enabled);
 }
 
 static ssize_t
-pm_trace_store(struct kset *kset, const char *buf, size_t n)
+pm_trace_store(struct kobject *kobj, struct kobj_attribute *attr,
+              const char *buf, size_t n)
 {
        int val;
 
@@ -363,30 +201,45 @@ pm_trace_store(struct kset *kset, const char *buf, size_t n)
 }
 
 power_attr(pm_trace);
+#endif /* CONFIG_PM_TRACE */
 
 static struct attribute * g[] = {
        &state_attr.attr,
+#ifdef CONFIG_PM_TRACE
        &pm_trace_attr.attr,
+#endif
+#if defined(CONFIG_PM_SLEEP) && defined(CONFIG_PM_DEBUG)
+       &pm_test_attr.attr,
+#endif
        NULL,
 };
-#else
-static struct attribute * g[] = {
-       &state_attr.attr,
-       NULL,
-};
-#endif /* CONFIG_PM_TRACE */
 
 static struct attribute_group attr_group = {
        .attrs = g,
 };
 
+#ifdef CONFIG_PM_RUNTIME
+struct workqueue_struct *pm_wq;
+
+static int __init pm_start_workqueue(void)
+{
+       pm_wq = create_freezeable_workqueue("pm");
+
+       return pm_wq ? 0 : -ENOMEM;
+}
+#else
+static inline int pm_start_workqueue(void) { return 0; }
+#endif
 
 static int __init pm_init(void)
 {
-       int error = subsystem_register(&power_subsys);
-       if (!error)
-               error = sysfs_create_group(&power_subsys.kobj,&attr_group);
-       return error;
+       int error = pm_start_workqueue();
+       if (error)
+               return error;
+       power_kobj = kobject_create_and_add("power", NULL);
+       if (!power_kobj)
+               return -ENOMEM;
+       return sysfs_create_group(power_kobj, &attr_group);
 }
 
 core_initcall(pm_init);