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authorDomenico Andreoli <domenico.andreoli@linux.com>2020-05-07 09:19:52 +0200
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2020-05-19 17:48:08 +0200
commitab7e9b067f3d9cbec28cfca51d341efb421b7a51 (patch)
tree945ac12fc98f52d44b7f44bff01837cd62b9eb3e /kernel/power
parent3a4ccdb92e1e0f51844c8b60f2c0f48a4a620000 (diff)
downloadlinux-ab7e9b067f3d9cbec28cfca51d341efb421b7a51.tar.bz2
PM: hibernate: Incorporate concurrency handling
Hibernation concurrency handling is currently delegated to user.c, where it's also used for regulating the access to the snapshot device. In the prospective of making user.c a separate configuration option, such mutual exclusion is brought into hibernate.c and made available through accessor helpers hereby introduced. Signed-off-by: Domenico Andreoli <domenico.andreoli@linux.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'kernel/power')
-rw-r--r--kernel/power/hibernate.c20
-rw-r--r--kernel/power/power.h4
-rw-r--r--kernel/power/user.c10
3 files changed, 22 insertions, 12 deletions
diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c
index 30bd28d1d418..02ec716a4927 100644
--- a/kernel/power/hibernate.c
+++ b/kernel/power/hibernate.c
@@ -67,6 +67,18 @@ bool freezer_test_done;
static const struct platform_hibernation_ops *hibernation_ops;
+static atomic_t hibernate_atomic = ATOMIC_INIT(1);
+
+bool hibernate_acquire(void)
+{
+ return atomic_add_unless(&hibernate_atomic, -1, 0);
+}
+
+void hibernate_release(void)
+{
+ atomic_inc(&hibernate_atomic);
+}
+
bool hibernation_available(void)
{
return nohibernate == 0 && !security_locked_down(LOCKDOWN_HIBERNATION);
@@ -704,7 +716,7 @@ int hibernate(void)
lock_system_sleep();
/* The snapshot device should not be opened while we're running */
- if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
+ if (!hibernate_acquire()) {
error = -EBUSY;
goto Unlock;
}
@@ -775,7 +787,7 @@ int hibernate(void)
Exit:
__pm_notifier_call_chain(PM_POST_HIBERNATION, nr_calls, NULL);
pm_restore_console();
- atomic_inc(&snapshot_device_available);
+ hibernate_release();
Unlock:
unlock_system_sleep();
pr_info("hibernation exit\n");
@@ -880,7 +892,7 @@ static int software_resume(void)
goto Unlock;
/* The snapshot device should not be opened while we're running */
- if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
+ if (!hibernate_acquire()) {
error = -EBUSY;
swsusp_close(FMODE_READ);
goto Unlock;
@@ -911,7 +923,7 @@ static int software_resume(void)
__pm_notifier_call_chain(PM_POST_RESTORE, nr_calls, NULL);
pm_restore_console();
pr_info("resume failed (%d)\n", error);
- atomic_inc(&snapshot_device_available);
+ hibernate_release();
/* For success case, the suspend path will release the lock */
Unlock:
mutex_unlock(&system_transition_mutex);
diff --git a/kernel/power/power.h b/kernel/power/power.h
index 7cdc64dc2373..ba2094db6294 100644
--- a/kernel/power/power.h
+++ b/kernel/power/power.h
@@ -154,8 +154,8 @@ extern int snapshot_write_next(struct snapshot_handle *handle);
extern void snapshot_write_finalize(struct snapshot_handle *handle);
extern int snapshot_image_loaded(struct snapshot_handle *handle);
-/* If unset, the snapshot device cannot be open. */
-extern atomic_t snapshot_device_available;
+extern bool hibernate_acquire(void);
+extern void hibernate_release(void);
extern sector_t alloc_swapdev_block(int swap);
extern void free_all_swap_pages(int swap);
diff --git a/kernel/power/user.c b/kernel/power/user.c
index 7959449765d9..98548d1cf8a6 100644
--- a/kernel/power/user.c
+++ b/kernel/power/user.c
@@ -37,8 +37,6 @@ static struct snapshot_data {
bool free_bitmaps;
} snapshot_state;
-atomic_t snapshot_device_available = ATOMIC_INIT(1);
-
static int snapshot_open(struct inode *inode, struct file *filp)
{
struct snapshot_data *data;
@@ -49,13 +47,13 @@ static int snapshot_open(struct inode *inode, struct file *filp)
lock_system_sleep();
- if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
+ if (!hibernate_acquire()) {
error = -EBUSY;
goto Unlock;
}
if ((filp->f_flags & O_ACCMODE) == O_RDWR) {
- atomic_inc(&snapshot_device_available);
+ hibernate_release();
error = -ENOSYS;
goto Unlock;
}
@@ -92,7 +90,7 @@ static int snapshot_open(struct inode *inode, struct file *filp)
__pm_notifier_call_chain(PM_POST_RESTORE, nr_calls, NULL);
}
if (error)
- atomic_inc(&snapshot_device_available);
+ hibernate_release();
data->frozen = false;
data->ready = false;
@@ -122,7 +120,7 @@ static int snapshot_release(struct inode *inode, struct file *filp)
}
pm_notifier_call_chain(data->mode == O_RDONLY ?
PM_POST_HIBERNATION : PM_POST_RESTORE);
- atomic_inc(&snapshot_device_available);
+ hibernate_release();
unlock_system_sleep();