From: Rafael J. Wysocki <rjw@xxxxxxx>
Make it possible to register suspend notifiers so that subsystems can perform
suspend-related operations which should not be carried out by device drivers'
.suspend() and .resume() routines.
Signed-off-by: Rafael J. Wysocki <rjw@xxxxxxx>
---
Documentation/power/suspend-notifiers.txt | 41 ++++++++++++++++++++++++
include/linux/notifier.h | 6 +++
include/linux/suspend.h | 27 +++++++++++++--
kernel/power/Makefile | 2 -
kernel/power/disk.c | 21 ++++++++++++
kernel/power/main.c | 13 +++++++
kernel/power/notify.c | 51 ++++++++++++++++++++++++++++++
kernel/power/power.h | 3 +
kernel/power/user.c | 19 +++++++++++
9 files changed, 178 insertions(+), 5 deletions(-)
Index: linux-2.6.21-rc6-mm1/kernel/power/notify.c
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ linux-2.6.21-rc6-mm1/kernel/power/notify.c 2007-04-21 23:24:50.000000000 +0200
@@ -0,0 +1,51 @@
+/*
+ * linux/kernel/power/notify.c
+ *
+ * This file contains functions used for registering and calling suspend
+ * notifiers that can be used by subsystems for carrying out some special
+ * suspend-related operations.
+ *
+ * Copyright (C) 2007 Rafael J. Wysocki <rjw@xxxxxxx>
+ *
+ * This file is released under the GPLv2.
+ *
+ */
+
+#include <linux/smp.h>
+#include <linux/notifier.h>
+#include <linux/module.h>
+#include <linux/suspend.h>
+
+static DEFINE_MUTEX(suspend_notifier_lock);
+
+static RAW_NOTIFIER_HEAD(suspend_chain);
+
+int register_suspend_notifier(struct notifier_block *nb)
+{
+ int ret;
+ mutex_lock(&suspend_notifier_lock);
+ ret = raw_notifier_chain_register(&suspend_chain, nb);
+ mutex_unlock(&suspend_notifier_lock);
+ return ret;
+}
+EXPORT_SYMBOL(register_suspend_notifier);
+
+void unregister_suspend_notifier(struct notifier_block *nb)
+{
+ mutex_lock(&suspend_notifier_lock);
+ raw_notifier_chain_unregister(&suspend_chain, nb);
+ mutex_unlock(&suspend_notifier_lock);
+}
+EXPORT_SYMBOL(unregister_suspend_notifier);
+
+int suspend_notifier_call_chain(unsigned long val)
+{
+ int error = 0;
+
+ mutex_lock(&suspend_notifier_lock);
+ if (raw_notifier_call_chain(&suspend_chain, val, NULL) == NOTIFY_BAD)
+ error = -EINVAL;
+
+ mutex_unlock(&suspend_notifier_lock);
+ return error;
+}
Index: linux-2.6.21-rc6-mm1/include/linux/suspend.h
===================================================================
--- linux-2.6.21-rc6-mm1.orig/include/linux/suspend.h 2007-04-21 23:24:44.000000000 +0200
+++ linux-2.6.21-rc6-mm1/include/linux/suspend.h 2007-04-21 23:24:50.000000000 +0200
@@ -24,15 +24,16 @@ struct pbe {
extern void drain_local_pages(void);
extern void mark_free_pages(struct zone *zone);
-#if defined(CONFIG_PM) && defined(CONFIG_VT) && defined(CONFIG_VT_CONSOLE)
+#ifdef CONFIG_PM
+#if defined(CONFIG_VT) && defined(CONFIG_VT_CONSOLE)
extern int pm_prepare_console(void);
extern void pm_restore_console(void);
#else
static inline int pm_prepare_console(void) { return 0; }
static inline void pm_restore_console(void) {}
-#endif
+#endif /* defined(CONFIG_VT) && defined(CONFIG_VT_CONSOLE) */
-#if defined(CONFIG_PM) && defined(CONFIG_SOFTWARE_SUSPEND)
+#ifdef CONFIG_SOFTWARE_SUSPEND
/* kernel/power/swsusp.c */
extern int software_suspend(void);
/* kernel/power/snapshot.c */
@@ -52,7 +53,7 @@ static inline void register_nosave_regio
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) {}
-#endif /* defined(CONFIG_PM) && defined(CONFIG_SOFTWARE_SUSPEND) */
+#endif /* CONFIG_SOFTWARE_SUSPEND */
void save_processor_state(void);
void restore_processor_state(void);
@@ -60,4 +61,22 @@ struct saved_context;
void __save_processor_state(struct saved_context *ctxt);
void __restore_processor_state(struct saved_context *ctxt);
+int register_suspend_notifier(struct notifier_block *nb);
+void unregister_suspend_notifier(struct notifier_block *nb);
+
+#define suspend_notifier(fn, pri) { \
+ static struct notifier_block fn##_nb = \
+ { .notifier_call = fn, .priority = pri }; \
+ register_suspend_notifier(&fn##_nb); \
+}
+#else /* CONFIG_PM */
+static inline int register_suspend_notifier(struct notifier_block *nb) {
+ return 0;
+}
+static inline void unregister_suspend_notifier(struct notifier_block *nb) {
+}
+
+#define suspend_notifier(fn, pri) do { (void)(fn); } while (0)
+#endif
+
#endif /* _LINUX_SWSUSP_H */
Index: linux-2.6.21-rc6-mm1/kernel/power/Makefile
===================================================================
--- linux-2.6.21-rc6-mm1.orig/kernel/power/Makefile 2007-04-21 23:24:28.000000000 +0200
+++ linux-2.6.21-rc6-mm1/kernel/power/Makefile 2007-04-21 23:24:50.000000000 +0200
@@ -3,7 +3,7 @@ ifeq ($(CONFIG_PM_DEBUG),y)
EXTRA_CFLAGS += -DDEBUG
endif
-obj-y := main.o process.o console.o
+obj-y := main.o process.o console.o notify.o
obj-$(CONFIG_PM_LEGACY) += pm.o
obj-$(CONFIG_SOFTWARE_SUSPEND) += swsusp.o disk.o snapshot.o swap.o user.o
Index: linux-2.6.21-rc6-mm1/kernel/power/power.h
===================================================================
--- linux-2.6.21-rc6-mm1.orig/kernel/power/power.h 2007-04-21 23:24:44.000000000 +0200
+++ linux-2.6.21-rc6-mm1/kernel/power/power.h 2007-04-21 23:24:50.000000000 +0200
@@ -170,3 +170,6 @@ extern int suspend_enter(suspend_state_t
struct timeval;
extern void swsusp_show_speed(struct timeval *, struct timeval *,
unsigned int, char *);
+
+/* kernel/power/notify.c */
+extern int suspend_notifier_call_chain(unsigned long val);
Index: linux-2.6.21-rc6-mm1/include/linux/notifier.h
===================================================================
--- linux-2.6.21-rc6-mm1.orig/include/linux/notifier.h 2007-04-21 23:24:28.000000000 +0200
+++ linux-2.6.21-rc6-mm1/include/linux/notifier.h 2007-04-21 23:24:50.000000000 +0200
@@ -197,5 +197,11 @@ extern int __srcu_notifier_call_chain(st
#define CPU_LOCK_ACQUIRE 0x0008 /* Acquire all hotcpu locks */
#define CPU_LOCK_RELEASE 0x0009 /* Release all hotcpu locks */
+#define SUSPEND_PREPARE 0x0002 /* Going to freeze tasks */
+#define SUSPEND_ENTER_PREPARE 0x0003 /* Tasks are frozen, we are suspending */
+#define SUSPEND_THAW_PREPARE 0x0004 /* Going to thaw frozen tasks */
+#define SUSPEND_FINISHED 0x0005 /* Tasks have been thawed */
+#define SUSPEND_RESTORE_PREPARE 0x0006 /* STD restore is going to happen */
+
#endif /* __KERNEL__ */
#endif /* _LINUX_NOTIFIER_H */
Index: linux-2.6.21-rc6-mm1/kernel/power/disk.c
===================================================================
--- linux-2.6.21-rc6-mm1.orig/kernel/power/disk.c 2007-04-21 23:24:28.000000000 +0200
+++ linux-2.6.21-rc6-mm1/kernel/power/disk.c 2007-04-21 23:24:50.000000000 +0200
@@ -114,6 +114,7 @@ static int prepare_processes(void)
pm_prepare_console();
if (freeze_processes()) {
error = -EBUSY;
+ suspend_notifier_call_chain(SUSPEND_THAW_PREPARE);
unprepare_processes();
}
return error;
@@ -139,6 +140,10 @@ int pm_suspend_disk(void)
if (error)
goto Exit;
+ error = suspend_notifier_call_chain(SUSPEND_PREPARE);
+ if (error)
+ goto Finish;
+
error = prepare_processes();
if (error)
goto Finish;
@@ -149,6 +154,10 @@ int pm_suspend_disk(void)
goto Thaw;
}
+ error = suspend_notifier_call_chain(SUSPEND_ENTER_PREPARE);
+ if (error)
+ goto Thaw;
+
/* Free memory before shutting down devices. */
error = swsusp_shrink_memory();
if (error)
@@ -205,8 +214,10 @@ int pm_suspend_disk(void)
device_resume();
resume_console();
Thaw:
+ suspend_notifier_call_chain(SUSPEND_THAW_PREPARE);
unprepare_processes();
Finish:
+ suspend_notifier_call_chain(SUSPEND_FINISHED);
free_basic_memory_bitmaps();
Exit:
atomic_inc(&snapshot_device_available);
@@ -267,6 +278,10 @@ static int software_resume(void)
if (error)
goto Finish;
+ error = suspend_notifier_call_chain(SUSPEND_PREPARE);
+ if (error)
+ goto Done;
+
pr_debug("PM: Preparing processes for restore.\n");
error = prepare_processes();
if (error) {
@@ -282,6 +297,10 @@ static int software_resume(void)
goto Thaw;
}
+ error = suspend_notifier_call_chain(SUSPEND_RESTORE_PREPARE);
+ if (error)
+ goto Thaw;
+
pr_debug("PM: Preparing devices for restore.\n");
suspend_console();
@@ -300,8 +319,10 @@ static int software_resume(void)
resume_console();
Thaw:
printk(KERN_ERR "PM: Restore failed, recovering.\n");
+ suspend_notifier_call_chain(SUSPEND_THAW_PREPARE);
unprepare_processes();
Done:
+ suspend_notifier_call_chain(SUSPEND_FINISHED);
free_basic_memory_bitmaps();
Finish:
atomic_inc(&snapshot_device_available);
Index: linux-2.6.21-rc6-mm1/kernel/power/main.c
===================================================================
--- linux-2.6.21-rc6-mm1.orig/kernel/power/main.c 2007-04-21 23:24:28.000000000 +0200
+++ linux-2.6.21-rc6-mm1/kernel/power/main.c 2007-04-21 23:24:50.000000000 +0200
@@ -86,11 +86,19 @@ static int suspend_prepare(suspend_state
pm_prepare_console();
+ error = suspend_notifier_call_chain(SUSPEND_PREPARE);
+ if (error)
+ goto Finish;
+
if (freeze_processes()) {
error = -EAGAIN;
goto Thaw;
}
+ error = suspend_notifier_call_chain(SUSPEND_ENTER_PREPARE);
+ if (error)
+ goto Thaw;
+
if ((free_pages = global_page_state(NR_FREE_PAGES))
< FREE_PAGE_NUMBER) {
pr_debug("PM: free some memory\n");
@@ -123,8 +131,11 @@ static int suspend_prepare(suspend_state
device_resume();
resume_console();
Thaw:
+ suspend_notifier_call_chain(SUSPEND_THAW_PREPARE);
thaw_processes();
+ Finish:
pm_restore_console();
+ suspend_notifier_call_chain(SUSPEND_FINISHED);
return error;
}
@@ -162,8 +173,10 @@ static void suspend_finish(suspend_state
pm_finish(state);
device_resume();
resume_console();
+ suspend_notifier_call_chain(SUSPEND_THAW_PREPARE);
thaw_processes();
pm_restore_console();
+ suspend_notifier_call_chain(SUSPEND_FINISHED);
}
Index: linux-2.6.21-rc6-mm1/kernel/power/user.c
===================================================================
--- linux-2.6.21-rc6-mm1.orig/kernel/power/user.c 2007-04-21 23:24:28.000000000 +0200
+++ linux-2.6.21-rc6-mm1/kernel/power/user.c 2007-04-21 23:24:50.000000000 +0200
@@ -148,6 +148,10 @@ static inline int snapshot_suspend(int p
int error;
mutex_lock(&pm_mutex);
+ error = suspend_notifier_call_chain(SUSPEND_ENTER_PREPARE);
+ if (error)
+ goto Finish;
+
/* Free memory before shutting down devices. */
error = swsusp_shrink_memory();
if (error)
@@ -186,6 +190,10 @@ static inline int snapshot_restore(int p
mutex_lock(&pm_mutex);
pm_prepare_console();
+ error = suspend_notifier_call_chain(SUSPEND_RESTORE_PREPARE);
+ if (error)
+ goto Finish;
+
if (platform_suspend) {
error = platform_prepare();
if (error)
@@ -236,7 +244,12 @@ static int snapshot_ioctl(struct inode *
if (data->frozen)
break;
mutex_lock(&pm_mutex);
+ error = suspend_notifier_call_chain(SUSPEND_PREPARE);
+ if (error)
+ break;
+
if (freeze_processes()) {
+ suspend_notifier_call_chain(SUSPEND_THAW_PREPARE);
thaw_processes();
error = -EBUSY;
}
@@ -249,7 +262,9 @@ static int snapshot_ioctl(struct inode *
if (!data->frozen)
break;
mutex_lock(&pm_mutex);
+ suspend_notifier_call_chain(SUSPEND_THAW_PREPARE);
thaw_processes();
+ suspend_notifier_call_chain(SUSPEND_FINISHED);
mutex_unlock(&pm_mutex);
data->frozen = 0;
break;
@@ -350,6 +365,10 @@ static int snapshot_ioctl(struct inode *
break;
}
+ error = suspend_notifier_call_chain(SUSPEND_ENTER_PREPARE);
+ if (error)
+ break;
+
if (pm_ops->prepare) {
error = pm_ops->prepare(PM_SUSPEND_MEM);
if (error)
Index: linux-2.6.21-rc6-mm1/Documentation/power/suspend-notifiers.txt
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ linux-2.6.21-rc6-mm1/Documentation/power/suspend-notifiers.txt 2007-04-21 23:24:50.000000000 +0200
@@ -0,0 +1,41 @@
+Suspend notifiers
+ (C) 2007 Rafael J. Wysocki <rjw@xxxxxxx>, GPL
+
+There are some operations that device drivers may want to carry out in their
+.suspend() routines, but shouldn't, because they can cause a 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 may want
+to carry out before a suspend or after a resume, requiring the system to be
+fully functional, so the drivers' .suspend() and .resume() routines are not
+suitable for this purpose.
+
+The subsystems that have such needs can register suspend notifiers that will be
+notified of the following events by the suspend core:
+
+SUSPEND_PREPARE the system is going to suspend, tasks will be frozen
+ immediately
+
+SUSPEND_ENTER_PREPARE tasks have been frozen, memory is going to be freed
+ and devices are going to be suspended
+
+SUSPEND_THAW_PREPARE devices have been resumed, tasks will be thawed
+ immediately
+
+SUSPEND_FINISHED the resume is complete, the system is fully functional
+
+SUSPEND_RESTORE_PREPARE the system is preparing to restore the swsusp's suspend
+ image, tasks have been frozen and devices are going to
+ be suspended
+
+It is generally assumed that whatever the notifiers do for SUSPEND_PREPARE,
+should be undone for SUSPEND_FINISHED, and what is done for
+SUSPEND_ENTER_PREPARE, should be undone for SUSPEND_FINISHED (eg. if memory is
+allocated for SUSPEND_ENTER_PREPARE, it should be freed for SUSPEND_FINISHED).
+
+The suspend notifiers 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_suspend_notifier() and
+unregister_suspend_notifier(), respectively, defined in kernel/power/notify.c .
+If you don't need to unregister the notifier, you can also use the
+suspend_notifier() macro, defined in include/linux/suspend.h .
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