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Message-ID: <20210624092615.824051127@infradead.org>
Date: Thu, 24 Jun 2021 11:21:57 +0200
From: Peter Zijlstra <peterz@...radead.org>
To: rjw@...ysocki.net, oleg@...hat.com, mingo@...nel.org,
vincent.guittot@...aro.org, dietmar.eggemann@....com,
rostedt@...dmis.org, mgorman@...e.de, Will Deacon <will@...nel.org>
Cc: linux-kernel@...r.kernel.org, peterz@...radead.org, tj@...nel.org,
linux-pm@...r.kernel.org
Subject: [PATCH v2 1/4] freezer: Have {,un}lock_system_sleep() save/restore flags
Rafael explained that the reason for having both PF_NOFREEZE and
PF_FREEZER_SKIP is that {,un}lock_system_sleep() is callable from
kthread context that has previously called set_freezable().
In preparation of merging the flags, have {,un}lock_system_slee() save
and restore current->flags.
Signed-off-by: Peter Zijlstra (Intel) <peterz@...radead.org>
---
drivers/scsi/scsi_transport_spi.c | 7 ++++---
include/linux/suspend.h | 8 ++++----
kernel/power/hibernate.c | 35 ++++++++++++++++++++++-------------
kernel/power/main.c | 16 ++++++++++------
kernel/power/suspend.c | 12 ++++++++----
kernel/power/user.c | 24 ++++++++++++++----------
6 files changed, 62 insertions(+), 40 deletions(-)
--- a/drivers/scsi/scsi_transport_spi.c
+++ b/drivers/scsi/scsi_transport_spi.c
@@ -998,8 +998,9 @@ void
spi_dv_device(struct scsi_device *sdev)
{
struct scsi_target *starget = sdev->sdev_target;
- u8 *buffer;
const int len = SPI_MAX_ECHO_BUFFER_SIZE*2;
+ unsigned int sleep_flags;
+ u8 *buffer;
/*
* Because this function and the power management code both call
@@ -1007,7 +1008,7 @@ spi_dv_device(struct scsi_device *sdev)
* while suspend or resume is in progress. Hence the
* lock/unlock_system_sleep() calls.
*/
- lock_system_sleep();
+ sleep_flags = lock_system_sleep();
if (scsi_autopm_get_device(sdev))
goto unlock_system_sleep;
@@ -1058,7 +1059,7 @@ spi_dv_device(struct scsi_device *sdev)
scsi_autopm_put_device(sdev);
unlock_system_sleep:
- unlock_system_sleep();
+ unlock_system_sleep(sleep_flags);
}
EXPORT_SYMBOL(spi_dv_device);
--- a/include/linux/suspend.h
+++ b/include/linux/suspend.h
@@ -518,8 +518,8 @@ extern bool pm_save_wakeup_count(unsigne
extern void pm_wakep_autosleep_enabled(bool set);
extern void pm_print_active_wakeup_sources(void);
-extern void lock_system_sleep(void);
-extern void unlock_system_sleep(void);
+extern unsigned int lock_system_sleep(void);
+extern void unlock_system_sleep(unsigned int);
#else /* !CONFIG_PM_SLEEP */
@@ -542,8 +542,8 @@ static inline void pm_system_wakeup(void
static inline void pm_wakeup_clear(bool reset) {}
static inline void pm_system_irq_wakeup(unsigned int irq_number) {}
-static inline void lock_system_sleep(void) {}
-static inline void unlock_system_sleep(void) {}
+static inline unsigned int lock_system_sleep(void) { return 0; }
+static inline void unlock_system_sleep(unsigned int flags) {}
#endif /* !CONFIG_PM_SLEEP */
--- a/kernel/power/hibernate.c
+++ b/kernel/power/hibernate.c
@@ -90,20 +90,24 @@ bool hibernation_available(void)
*/
void hibernation_set_ops(const struct platform_hibernation_ops *ops)
{
+ unsigned int sleep_flags;
+
if (ops && !(ops->begin && ops->end && ops->pre_snapshot
&& ops->prepare && ops->finish && ops->enter && ops->pre_restore
&& ops->restore_cleanup && ops->leave)) {
WARN_ON(1);
return;
}
- lock_system_sleep();
+
+ sleep_flags = lock_system_sleep();
+
hibernation_ops = ops;
if (ops)
hibernation_mode = HIBERNATION_PLATFORM;
else if (hibernation_mode == HIBERNATION_PLATFORM)
hibernation_mode = HIBERNATION_SHUTDOWN;
- unlock_system_sleep();
+ unlock_system_sleep(sleep_flags);
}
EXPORT_SYMBOL_GPL(hibernation_set_ops);
@@ -707,6 +711,7 @@ static int load_image_and_restore(void)
int hibernate(void)
{
bool snapshot_test = false;
+ unsigned int sleep_flags;
int error;
if (!hibernation_available()) {
@@ -714,7 +719,7 @@ int hibernate(void)
return -EPERM;
}
- lock_system_sleep();
+ sleep_flags = lock_system_sleep();
/* The snapshot device should not be opened while we're running */
if (!hibernate_acquire()) {
error = -EBUSY;
@@ -788,7 +793,7 @@ int hibernate(void)
pm_restore_console();
hibernate_release();
Unlock:
- unlock_system_sleep();
+ unlock_system_sleep(sleep_flags);
pr_info("hibernation exit\n");
return error;
@@ -803,9 +808,10 @@ int hibernate(void)
*/
int hibernate_quiet_exec(int (*func)(void *data), void *data)
{
+ unsigned int sleep_flags;
int error;
- lock_system_sleep();
+ sleep_flags = lock_system_sleep();
if (!hibernate_acquire()) {
error = -EBUSY;
@@ -885,7 +891,7 @@ int hibernate_quiet_exec(int (*func)(voi
hibernate_release();
unlock:
- unlock_system_sleep();
+ unlock_system_sleep(sleep_flags);
return error;
}
@@ -1094,11 +1100,12 @@ static ssize_t disk_show(struct kobject
static ssize_t disk_store(struct kobject *kobj, struct kobj_attribute *attr,
const char *buf, size_t n)
{
+ int mode = HIBERNATION_INVALID;
+ unsigned int sleep_flags;
int error = 0;
- int i;
int len;
char *p;
- int mode = HIBERNATION_INVALID;
+ int i;
if (!hibernation_available())
return -EPERM;
@@ -1106,7 +1113,7 @@ static ssize_t disk_store(struct kobject
p = memchr(buf, '\n', n);
len = p ? p - buf : n;
- lock_system_sleep();
+ sleep_flags = lock_system_sleep();
for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
if (len == strlen(hibernation_modes[i])
&& !strncmp(buf, hibernation_modes[i], len)) {
@@ -1136,7 +1143,7 @@ static ssize_t disk_store(struct kobject
if (!error)
pm_pr_dbg("Hibernation mode set to '%s'\n",
hibernation_modes[mode]);
- unlock_system_sleep();
+ unlock_system_sleep(sleep_flags);
return error ? error : n;
}
@@ -1152,9 +1159,10 @@ static ssize_t resume_show(struct kobjec
static ssize_t resume_store(struct kobject *kobj, struct kobj_attribute *attr,
const char *buf, size_t n)
{
- dev_t res;
+ unsigned int sleep_flags;
int len = n;
char *name;
+ dev_t res;
if (len && buf[len-1] == '\n')
len--;
@@ -1167,9 +1175,10 @@ static ssize_t resume_store(struct kobje
if (!res)
return -EINVAL;
- lock_system_sleep();
+ sleep_flags = lock_system_sleep();
swsusp_resume_device = res;
- unlock_system_sleep();
+ unlock_system_sleep(sleep_flags);
+
pm_pr_dbg("Configured hibernation resume from disk to %u\n",
swsusp_resume_device);
noresume = 0;
--- a/kernel/power/main.c
+++ b/kernel/power/main.c
@@ -21,14 +21,16 @@
#ifdef CONFIG_PM_SLEEP
-void lock_system_sleep(void)
+unsigned int lock_system_sleep(void)
{
+ unsigned int flags = current->flags;
current->flags |= PF_FREEZER_SKIP;
mutex_lock(&system_transition_mutex);
+ return flags;
}
EXPORT_SYMBOL_GPL(lock_system_sleep);
-void unlock_system_sleep(void)
+void unlock_system_sleep(unsigned int flags)
{
/*
* Don't use freezer_count() because we don't want the call to
@@ -46,7 +48,8 @@ void unlock_system_sleep(void)
* Which means, if we use try_to_freeze() here, it would make them
* enter the refrigerator, thus causing hibernation to lockup.
*/
- current->flags &= ~PF_FREEZER_SKIP;
+ if (!(flags & PF_FREEZER_SKIP))
+ current->flags &= ~PF_FREEZER_SKIP;
mutex_unlock(&system_transition_mutex);
}
EXPORT_SYMBOL_GPL(unlock_system_sleep);
@@ -260,16 +263,17 @@ static ssize_t pm_test_show(struct kobje
static ssize_t pm_test_store(struct kobject *kobj, struct kobj_attribute *attr,
const char *buf, size_t n)
{
+ unsigned int sleep_flags;
const char * const *s;
+ int error = -EINVAL;
int level;
char *p;
int len;
- int error = -EINVAL;
p = memchr(buf, '\n', n);
len = p ? p - buf : n;
- lock_system_sleep();
+ sleep_flags = lock_system_sleep();
level = TEST_FIRST;
for (s = &pm_tests[level]; level <= TEST_MAX; s++, level++)
@@ -279,7 +283,7 @@ static ssize_t pm_test_store(struct kobj
break;
}
- unlock_system_sleep();
+ unlock_system_sleep(sleep_flags);
return error ? error : n;
}
--- a/kernel/power/suspend.c
+++ b/kernel/power/suspend.c
@@ -75,9 +75,11 @@ EXPORT_SYMBOL_GPL(pm_suspend_default_s2i
void s2idle_set_ops(const struct platform_s2idle_ops *ops)
{
- lock_system_sleep();
+ unsigned int sleep_flags;
+
+ sleep_flags = lock_system_sleep();
s2idle_ops = ops;
- unlock_system_sleep();
+ unlock_system_sleep(sleep_flags);
}
static void s2idle_begin(void)
@@ -202,7 +204,9 @@ __setup("mem_sleep_default=", mem_sleep_
*/
void suspend_set_ops(const struct platform_suspend_ops *ops)
{
- lock_system_sleep();
+ unsigned int sleep_flags;
+
+ sleep_flags = lock_system_sleep();
suspend_ops = ops;
@@ -218,7 +222,7 @@ void suspend_set_ops(const struct platfo
mem_sleep_current = PM_SUSPEND_MEM;
}
- unlock_system_sleep();
+ unlock_system_sleep(sleep_flags);
}
EXPORT_SYMBOL_GPL(suspend_set_ops);
--- a/kernel/power/user.c
+++ b/kernel/power/user.c
@@ -46,12 +46,13 @@ int is_hibernate_resume_dev(dev_t dev)
static int snapshot_open(struct inode *inode, struct file *filp)
{
struct snapshot_data *data;
+ unsigned int sleep_flags;
int error;
if (!hibernation_available())
return -EPERM;
- lock_system_sleep();
+ sleep_flags = lock_system_sleep();
if (!hibernate_acquire()) {
error = -EBUSY;
@@ -97,7 +98,7 @@ static int snapshot_open(struct inode *i
data->dev = 0;
Unlock:
- unlock_system_sleep();
+ unlock_system_sleep(sleep_flags);
return error;
}
@@ -105,8 +106,9 @@ static int snapshot_open(struct inode *i
static int snapshot_release(struct inode *inode, struct file *filp)
{
struct snapshot_data *data;
+ unsigned int sleep_flags;
- lock_system_sleep();
+ sleep_flags = lock_system_sleep();
swsusp_free();
data = filp->private_data;
@@ -123,7 +125,7 @@ static int snapshot_release(struct inode
PM_POST_HIBERNATION : PM_POST_RESTORE);
hibernate_release();
- unlock_system_sleep();
+ unlock_system_sleep(sleep_flags);
return 0;
}
@@ -131,11 +133,12 @@ static int snapshot_release(struct inode
static ssize_t snapshot_read(struct file *filp, char __user *buf,
size_t count, loff_t *offp)
{
+ loff_t pg_offp = *offp & ~PAGE_MASK;
struct snapshot_data *data;
+ unsigned int sleep_flags;
ssize_t res;
- loff_t pg_offp = *offp & ~PAGE_MASK;
- lock_system_sleep();
+ sleep_flags = lock_system_sleep();
data = filp->private_data;
if (!data->ready) {
@@ -156,7 +159,7 @@ static ssize_t snapshot_read(struct file
*offp += res;
Unlock:
- unlock_system_sleep();
+ unlock_system_sleep(sleep_flags);
return res;
}
@@ -164,11 +167,12 @@ static ssize_t snapshot_read(struct file
static ssize_t snapshot_write(struct file *filp, const char __user *buf,
size_t count, loff_t *offp)
{
+ loff_t pg_offp = *offp & ~PAGE_MASK;
struct snapshot_data *data;
+ unsigned int sleep_flags;
ssize_t res;
- loff_t pg_offp = *offp & ~PAGE_MASK;
- lock_system_sleep();
+ sleep_flags = lock_system_sleep();
data = filp->private_data;
@@ -190,7 +194,7 @@ static ssize_t snapshot_write(struct fil
if (res > 0)
*offp += res;
unlock:
- unlock_system_sleep();
+ unlock_system_sleep(sleep_flags);
return res;
}
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