Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762870AbXFBAkB (ORCPT ); Fri, 1 Jun 2007 20:40:01 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1760104AbXFBAjc (ORCPT ); Fri, 1 Jun 2007 20:39:32 -0400 Received: from ogre.sisk.pl ([217.79.144.158]:58350 "EHLO ogre.sisk.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759953AbXFBAja (ORCPT ); Fri, 1 Jun 2007 20:39:30 -0400 From: "Rafael J. Wysocki" To: pm list Subject: [RFC][PATCH -mm 1/2] PM: Introduce hibernation and suspend notifiers Date: Sat, 2 Jun 2007 02:43:19 +0200 User-Agent: KMail/1.9.5 Cc: LKML , Matthew Garrett , Nigel Cunningham , Pavel Machek , Alan Stern , Oliver Neukum References: <200705272229.21263.rjw@sisk.pl> <200706020241.53788.rjw@sisk.pl> In-Reply-To: <200706020241.53788.rjw@sisk.pl> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-2" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200706020243.20117.rjw@sisk.pl> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 11474 Lines: 299 From: Rafael J. Wysocki Make it possible to register hibernation and suspend notifiers, so that subsystems can perform hibernation-related or suspend-related operations that should not be carried out by device drivers' .suspend() and .resume() routines. Signed-off-by: Rafael J. Wysocki --- Documentation/power/notifiers.txt | 50 ++++++++++++++++++++++++++++++++++++++ include/linux/notifier.h | 6 ++++ include/linux/suspend.h | 37 +++++++++++++++++++++++++--- kernel/power/disk.c | 16 +++++++++--- kernel/power/main.c | 9 ++++++ kernel/power/power.h | 10 +++++++ kernel/power/user.c | 11 ++++++-- 7 files changed, 129 insertions(+), 10 deletions(-) Index: linux-2.6.22-rc3/include/linux/suspend.h =================================================================== --- linux-2.6.22-rc3.orig/include/linux/suspend.h 2007-05-31 00:00:38.000000000 +0200 +++ linux-2.6.22-rc3/include/linux/suspend.h 2007-06-01 22:55:01.000000000 +0200 @@ -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) @@ -72,7 +73,7 @@ extern unsigned long get_safe_page(gfp_t extern void hibernation_set_ops(struct hibernation_ops *ops); extern int hibernate(void); -#else +#else /* CONFIG_SOFTWARE_SUSPEND */ 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) {} static inline int swsusp_page_is_forbidden(struct page *p) { return 0; } @@ -81,7 +82,7 @@ static inline void swsusp_unset_page_fre 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 +90,34 @@ 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 */ + #endif /* _LINUX_SWSUSP_H */ Index: linux-2.6.22-rc3/kernel/power/power.h =================================================================== --- linux-2.6.22-rc3.orig/kernel/power/power.h 2007-05-31 00:00:38.000000000 +0200 +++ linux-2.6.22-rc3/kernel/power/power.h 2007-06-01 22:55:01.000000000 +0200 @@ -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; +} Index: linux-2.6.22-rc3/include/linux/notifier.h =================================================================== --- linux-2.6.22-rc3.orig/include/linux/notifier.h 2007-05-31 00:00:38.000000000 +0200 +++ linux-2.6.22-rc3/include/linux/notifier.h 2007-06-01 23:01:38.000000000 +0200 @@ -209,5 +209,11 @@ extern int __srcu_notifier_call_chain(st #define CPU_DOWN_FAILED_FROZEN (CPU_DOWN_FAILED | CPU_TASKS_FROZEN) #define CPU_DEAD_FROZEN (CPU_DEAD | 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 */ Index: linux-2.6.22-rc3/kernel/power/disk.c =================================================================== --- linux-2.6.22-rc3.orig/kernel/power/disk.c 2007-05-31 00:00:38.000000000 +0200 +++ linux-2.6.22-rc3/kernel/power/disk.c 2007-06-01 23:05:11.000000000 +0200 @@ -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; } Index: linux-2.6.22-rc3/kernel/power/main.c =================================================================== --- linux-2.6.22-rc3.orig/kernel/power/main.c 2007-05-31 00:00:38.000000000 +0200 +++ linux-2.6.22-rc3/kernel/power/main.c 2007-06-01 23:08:43.000000000 +0200 @@ -24,6 +24,8 @@ #include "power.h" +BLOCKING_NOTIFIER_HEAD(pm_chain_head); + /*This is just an arbitrary number */ #define FREE_PAGE_NUMBER (100) @@ -82,6 +84,10 @@ static int suspend_prepare(suspend_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()) { @@ -124,6 +130,8 @@ static int suspend_prepare(suspend_state Thaw: thaw_processes(); pm_restore_console(); + Finish: + pm_notifier_call_chain(PM_POST_SUSPEND); return error; } @@ -175,6 +183,7 @@ static void suspend_finish(suspend_state resume_console(); thaw_processes(); pm_restore_console(); + pm_notifier_call_chain(PM_POST_SUSPEND); } Index: linux-2.6.22-rc3/kernel/power/user.c =================================================================== --- linux-2.6.22-rc3.orig/kernel/power/user.c 2007-05-31 00:00:38.000000000 +0200 +++ linux-2.6.22-rc3/kernel/power/user.c 2007-06-01 23:15:58.000000000 +0200 @@ -149,10 +149,14 @@ static int snapshot_ioctl(struct inode * 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; @@ -163,6 +167,7 @@ static int snapshot_ioctl(struct inode * break; mutex_lock(&pm_mutex); thaw_processes(); + pm_notifier_call_chain(PM_POST_HIBERNATION); mutex_unlock(&pm_mutex); data->frozen = 0; break; Index: linux-2.6.22-rc3/Documentation/power/notifiers.txt =================================================================== --- /dev/null 1970-01-01 00:00:00.000000000 +0000 +++ linux-2.6.22-rc3/Documentation/power/notifiers.txt 2007-06-01 23:14:59.000000000 +0200 @@ -0,0 +1,50 @@ +Suspend notifiers + (C) 2007 Rafael J. Wysocki , 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 . - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/