Messages in this thread Patch in this message | | | Date | Sat, 09 Oct 2021 12:07:55 +0200 | From | Peter Zijlstra <> | Subject | [PATCH v3 1/6] freezer: Have {,un}lock_system_sleep() save/restore flags |
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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@infradead.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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