diff options
| -rw-r--r-- | Documentation/power/notifiers.txt | 50 | ||||
| -rw-r--r-- | include/linux/notifier.h | 6 | ||||
| -rw-r--r-- | include/linux/suspend.h | 48 | ||||
| -rw-r--r-- | kernel/power/disk.c | 16 | ||||
| -rw-r--r-- | kernel/power/main.c | 9 | ||||
| -rw-r--r-- | kernel/power/power.h | 10 | ||||
| -rw-r--r-- | kernel/power/user.c | 11 |
7 files changed, 138 insertions, 12 deletions
diff --git a/Documentation/power/notifiers.txt b/Documentation/power/notifiers.txt new file mode 100644 index 0000000..9293e4b --- /dev/null +++ b/Documentation/power/notifiers.txt @@ -0,0 +1,50 @@ +Suspend notifiers + (C) 2007 Rafael J. Wysocki <rjw@sisk.pl>, GPL + +There are some operations that device drivers may want to carry out in their +.suspend() routines, but shouldn't, because they can cause the hibernation or +suspend to fail. For example, a driver may want to allocate a substantial amount +of memory (like 50 MB) in .suspend(), but that shouldn't be done after the +swsusp's memory shrinker has run. + +Also, there may be some operations, that subsystems want to carry out before a +hibernation/suspend or after a restore/resume, requiring the system to be fully +functional, so the drivers' .suspend() and .resume() routines are not suitable +for this purpose. For example, device drivers may want to upload firmware to +their devices after a restore from a hibernation image, but they cannot do it by +calling request_firmware() from their .resume() routines (user land processes +are frozen at this point). The solution may be to load the firmware into +memory before processes are frozen and upload it from there in the .resume() +routine. Of course, a hibernation notifier may be used for this purpose. + +The subsystems that have such needs can register suspend notifiers that will be +called upon the following events by the suspend core: + +PM_HIBERNATION_PREPARE The system is going to hibernate or suspend, tasks will + be frozen immediately. + +PM_POST_HIBERNATION The system memory state has been restored from a + hibernation image or an error occured during the + hibernation. Device drivers' .resume() callbacks have + been executed and tasks have been thawed. + +PM_SUSPEND_PREPARE The system is preparing for a suspend. + +PM_POST_SUSPEND The system has just resumed or an error occured during + the suspend. Device drivers' .resume() callbacks have + been executed and tasks have been thawed. + +It is generally assumed that whatever the notifiers do for +PM_HIBERNATION_PREPARE, should be undone for PM_POST_HIBERNATION. Analogously, +operations performed for PM_SUSPEND_PREPARE should be reversed for +PM_POST_SUSPEND. Additionally, all of the notifiers are called for +PM_POST_HIBERNATION if one of them fails for PM_HIBERNATION_PREPARE, and +all of the notifiers are called for PM_POST_SUSPEND if one of them fails for +PM_SUSPEND_PREPARE. + +The hibernation and suspend notifiers are called with pm_mutex held. They are +defined in the usual way, but their last argument is meaningless (it is always +NULL). To register and/or unregister a suspend notifier use the functions +register_pm_notifier() and unregister_pm_notifier(), respectively, defined in +include/linux/suspend.h . If you don't need to unregister the notifier, you can +also use the pm_notifier() macro defined in include/linux/suspend.h . diff --git a/include/linux/notifier.h b/include/linux/notifier.h index 576f2bb..be3f2bb 100644 --- a/include/linux/notifier.h +++ b/include/linux/notifier.h @@ -212,5 +212,11 @@ extern int __srcu_notifier_call_chain(struct srcu_notifier_head *nh, #define CPU_DEAD_FROZEN (CPU_DEAD | CPU_TASKS_FROZEN) #define CPU_DYING_FROZEN (CPU_DYING | CPU_TASKS_FROZEN) +/* Hibernation and suspend events */ +#define PM_HIBERNATION_PREPARE 0x0001 /* Going to hibernate */ +#define PM_POST_HIBERNATION 0x0002 /* Hibernation finished */ +#define PM_SUSPEND_PREPARE 0x0003 /* Going to suspend the system */ +#define PM_POST_SUSPEND 0x0004 /* Suspend finished */ + #endif /* __KERNEL__ */ #endif /* _LINUX_NOTIFIER_H */ diff --git a/include/linux/suspend.h b/include/linux/suspend.h index d235c14..e8e6da3 100644 --- a/include/linux/suspend.h +++ b/include/linux/suspend.h @@ -54,7 +54,8 @@ struct hibernation_ops { void (*restore_cleanup)(void); }; -#if defined(CONFIG_PM) && defined(CONFIG_SOFTWARE_SUSPEND) +#ifdef CONFIG_PM +#ifdef CONFIG_SOFTWARE_SUSPEND /* kernel/power/snapshot.c */ extern void __register_nosave_region(unsigned long b, unsigned long e, int km); static inline void register_nosave_region(unsigned long b, unsigned long e) @@ -72,16 +73,14 @@ extern unsigned long get_safe_page(gfp_t gfp_mask); extern void hibernation_set_ops(struct hibernation_ops *ops); extern int hibernate(void); -#else -static inline void register_nosave_region(unsigned long b, unsigned long e) {} -static inline void register_nosave_region_late(unsigned long b, unsigned long e) {} +#else /* CONFIG_SOFTWARE_SUSPEND */ static inline int swsusp_page_is_forbidden(struct page *p) { return 0; } static inline void swsusp_set_page_free(struct page *p) {} static inline void swsusp_unset_page_free(struct page *p) {} static inline void hibernation_set_ops(struct hibernation_ops *ops) {} static inline int hibernate(void) { return -ENOSYS; } -#endif /* defined(CONFIG_PM) && defined(CONFIG_SOFTWARE_SUSPEND) */ +#endif /* CONFIG_SOFTWARE_SUSPEND */ void save_processor_state(void); void restore_processor_state(void); @@ -89,4 +88,43 @@ struct saved_context; void __save_processor_state(struct saved_context *ctxt); void __restore_processor_state(struct saved_context *ctxt); +/* kernel/power/main.c */ +extern struct blocking_notifier_head pm_chain_head; + +static inline int register_pm_notifier(struct notifier_block *nb) +{ + return blocking_notifier_chain_register(&pm_chain_head, nb); +} + +static inline int unregister_pm_notifier(struct notifier_block *nb) +{ + return blocking_notifier_chain_unregister(&pm_chain_head, nb); +} + +#define pm_notifier(fn, pri) { \ + static struct notifier_block fn##_nb = \ + { .notifier_call = fn, .priority = pri }; \ + register_pm_notifier(&fn##_nb); \ +} +#else /* CONFIG_PM */ + +static inline int register_pm_notifier(struct notifier_block *nb) +{ + return 0; +} + +static inline int unregister_pm_notifier(struct notifier_block *nb) +{ + return 0; +} + +#define pm_notifier(fn, pri) do { (void)(fn); } while (0) +#endif /* CONFIG_PM */ + +#if !defined CONFIG_SOFTWARE_SUSPEND || !defined(CONFIG_PM) +static inline void register_nosave_region(unsigned long b, unsigned long e) +{ +} +#endif + #endif /* _LINUX_SWSUSP_H */ diff --git a/kernel/power/disk.c b/kernel/power/disk.c index 885c653..324ac01 100644 --- a/kernel/power/disk.c +++ b/kernel/power/disk.c @@ -281,9 +281,16 @@ int hibernate(void) { int error; + mutex_lock(&pm_mutex); /* The snapshot device should not be opened while we're running */ - if (!atomic_add_unless(&snapshot_device_available, -1, 0)) - return -EBUSY; + if (!atomic_add_unless(&snapshot_device_available, -1, 0)) { + error = -EBUSY; + goto Unlock; + } + + error = pm_notifier_call_chain(PM_HIBERNATION_PREPARE); + if (error) + goto Exit; /* Allocate memory management structures */ error = create_basic_memory_bitmaps(); @@ -294,7 +301,6 @@ int hibernate(void) if (error) goto Finish; - mutex_lock(&pm_mutex); if (hibernation_mode == HIBERNATION_TESTPROC) { printk("swsusp debug: Waiting for 5 seconds.\n"); mdelay(5000); @@ -316,12 +322,14 @@ int hibernate(void) swsusp_free(); } Thaw: - mutex_unlock(&pm_mutex); unprepare_processes(); Finish: free_basic_memory_bitmaps(); Exit: + pm_notifier_call_chain(PM_POST_HIBERNATION); atomic_inc(&snapshot_device_available); + Unlock: + mutex_unlock(&pm_mutex); return error; } diff --git a/kernel/power/main.c b/kernel/power/main.c index fc45ed2..4d26ad3 100644 --- a/kernel/power/main.c +++ b/kernel/power/main.c @@ -23,6 +23,8 @@ #include "power.h" +BLOCKING_NOTIFIER_HEAD(pm_chain_head); + /*This is just an arbitrary number */ #define FREE_PAGE_NUMBER (100) @@ -78,6 +80,10 @@ static int suspend_prepare(suspend_state_t state) 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()) { @@ -125,6 +131,8 @@ static int suspend_prepare(suspend_state_t state) Thaw: thaw_processes(); pm_restore_console(); + Finish: + pm_notifier_call_chain(PM_POST_SUSPEND); return error; } @@ -176,6 +184,7 @@ static void suspend_finish(suspend_state_t state) resume_console(); thaw_processes(); pm_restore_console(); + pm_notifier_call_chain(PM_POST_SUSPEND); } diff --git a/kernel/power/power.h b/kernel/power/power.h index eab3603..01c2275 100644 --- a/kernel/power/power.h +++ b/kernel/power/power.h @@ -173,5 +173,15 @@ extern void swsusp_close(void); extern int suspend_enter(suspend_state_t state); struct timeval; +/* kernel/power/swsusp.c */ extern void swsusp_show_speed(struct timeval *, struct timeval *, unsigned int, char *); + +/* kernel/power/main.c */ +extern struct blocking_notifier_head pm_chain_head; + +static inline int pm_notifier_call_chain(unsigned long val) +{ + return (blocking_notifier_call_chain(&pm_chain_head, val, NULL) + == NOTIFY_BAD) ? -EINVAL : 0; +} diff --git a/kernel/power/user.c b/kernel/power/user.c index 1f24f30..7f19afe 100644 --- a/kernel/power/user.c +++ b/kernel/power/user.c @@ -151,10 +151,14 @@ static int snapshot_ioctl(struct inode *inode, struct file *filp, if (data->frozen) break; mutex_lock(&pm_mutex); - if (freeze_processes()) { - thaw_processes(); - error = -EBUSY; + error = pm_notifier_call_chain(PM_HIBERNATION_PREPARE); + if (!error) { + error = freeze_processes(); + if (error) + thaw_processes(); } + if (error) + pm_notifier_call_chain(PM_POST_HIBERNATION); mutex_unlock(&pm_mutex); if (!error) data->frozen = 1; @@ -165,6 +169,7 @@ static int snapshot_ioctl(struct inode *inode, struct file *filp, break; mutex_lock(&pm_mutex); thaw_processes(); + pm_notifier_call_chain(PM_POST_HIBERNATION); mutex_unlock(&pm_mutex); data->frozen = 0; break; |
