Merge branch 'pm-sleep'

Merge updates related to system suspend and hibernation for 6.19-rc1:

 - Replace snprintf() with scnprintf() in show_trace_dev_match()
   (Kaushlendra Kumar)

 - Fix memory allocation error handling in pm_vt_switch_required()
   (Malaya Kumar Rout)

 - Introduce CALL_PM_OP() macro and use it to simplify code in
   generic PM operations (Kaushlendra Kumar)

 - Add module param to backtrace all CPUs in the device power management
   watchdog (Sergey Senozhatsky)

 - Rework message printing in swsusp_save() (Rafael Wysocki)

 - Make it possible to change the number of hibernation compression
   threads (Xueqin Luo)

 - Clarify that only cgroup1 freezer uses PM freezer (Tejun Heo)

 - Add document on debugging shutdown hangs to PM documentation and
   correct a mistaken configuration option in it (Mario Limonciello)

 - Shut down wakeup source timer before removing the wakeup source from
   the list (Kaushlendra Kumar, Rafael Wysocki)

 - Introduce new PMSG_POWEROFF event for system shutdown handling with
   the help of PM device callbacks (Mario Limonciello)

 - Make pm_test delay interruptible by wakeup events (Riwen Lu)

 - Clean up kernel-doc comment style usage in the core hibernation
   code and remove unuseful comments from it (Sunday Adelodun, Rafael
   Wysocki)

 - Add support for handling wakeup events and aborting the suspend
   process while it is syncing file systems (Samuel Wu, Rafael Wysocki)

* pm-sleep: (21 commits)
  PM: hibernate: Extra cleanup of comments in swap handling code
  PM: sleep: Call pm_sleep_fs_sync() instead of ksys_sync_helper()
  PM: sleep: Add support for wakeup during filesystem sync
  PM: hibernate: Clean up kernel-doc comment style usage
  PM: suspend: Make pm_test delay interruptible by wakeup events
  usb: sl811-hcd: Add PM_EVENT_POWEROFF into suspend callbacks
  scsi: Add PM_EVENT_POWEROFF into suspend callbacks
  PM: Introduce new PMSG_POWEROFF event
  PM: wakeup: Update after recent wakeup source removal ordering change
  PM: wakeup: Delete timer before removing wakeup source from list
  Documentation: power: Correct a mistaken configuration option
  Documentation: power: Add document on debugging shutdown hangs
  freezer: Clarify that only cgroup1 freezer uses PM freezer
  PM: hibernate: add sysfs interface for hibernate_compression_threads
  PM: hibernate: make compression threads configurable
  PM: hibernate: dynamically allocate crc->unc_len/unc for configurable threads
  PM: hibernate: Rework message printing in swsusp_save()
  PM: dpm_watchdog: add module param to backtrace all CPUs
  PM: sleep: Introduce CALL_PM_OP() macro to simplify code
  PM: console: Fix memory allocation error handling in pm_vt_switch_required()
  ...

Author: rafaeljw

Documentation/ABI/testing/sysfs-power

@@ -454,3 +454,19 @@ Description:
 		disables it.  Reads from the file return the current value.
 		The default is "1" if the build-time "SUSPEND_SKIP_SYNC" config
 		flag is unset, or "0" otherwise.
+
+What:           /sys/power/hibernate_compression_threads
+Date:           October 2025
+Contact:        <luoxueqin@kylinos.cn>
+Description:
+                Controls the number of threads used for compression
+                and decompression of hibernation images.
+
+                The value can be adjusted at runtime to balance
+                performance and CPU utilization.
+
+                The change takes effect on the next hibernation or
+                resume operation.
+
+                Minimum value: 1
+                Default value: 3

Documentation/admin-guide/kernel-parameters.txt

@@ -1907,6 +1907,16 @@
 			/sys/power/pm_test). Only available when CONFIG_PM_DEBUG
 			is set. Default value is 5.
 
+	hibernate_compression_threads=
+			[HIBERNATION]
+			Set the number of threads used for compressing or decompressing
+			hibernation images.
+
+			Format: <integer>
+			Default: 3
+			Minimum: 1
+			Example: hibernate_compression_threads=4
+
 	highmem=nn[KMG]	[KNL,BOOT,EARLY] forces the highmem zone to have an exact
 			size of <nn>. This works even on boxes that have no
 			highmem otherwise. This also works to reduce highmem

Documentation/power/index.rst

@@ -19,6 +19,7 @@ Power Management
     power_supply_class
     runtime_pm
     s2ram
+    shutdown-debugging
     suspend-and-cpuhotplug
     suspend-and-interrupts
     swsusp-and-swap-files

Documentation/power/shutdown-debugging.rst

@@ -0,0 +1,53 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+Debugging Kernel Shutdown Hangs with pstore
++++++++++++++++++++++++++++++++++++++++++++
+
+Overview
+========
+If the system hangs while shutting down, the kernel logs may need to be
+retrieved to debug the issue.
+
+On systems that have a UART available, it is best to configure the kernel to use
+this UART for kernel console output.
+
+If a UART isn't available, the ``pstore`` subsystem provides a mechanism to
+persist this data across a system reset, allowing it to be retrieved on the next
+boot.
+
+Kernel Configuration
+====================
+To enable ``pstore`` and enable saving kernel ring buffer logs, set the
+following kernel configuration options:
+
+* ``CONFIG_PSTORE=y``
+* ``CONFIG_PSTORE_CONSOLE=y``
+
+Additionally, enable a backend to store the data. Depending upon your platform
+some potential options include:
+
+* ``CONFIG_EFI_VARS_PSTORE=y``
+* ``CONFIG_PSTORE_RAM=y``
+* ``CONFIG_CHROMEOS_PSTORE=y``
+* ``CONFIG_PSTORE_BLK=y``
+
+Kernel Command-line Parameters
+==============================
+Add these parameters to your kernel command line:
+
+* ``printk.always_kmsg_dump=Y``
+	* Forces the kernel to dump the entire message buffer to pstore during
+		shutdown
+* ``efi_pstore.pstore_disable=N``
+	* For EFI-based systems, ensures the EFI backend is active
+
+Userspace Interaction and Log Retrieval
+=======================================
+On the next boot after a hang, pstore logs will be available in the pstore
+filesystem (``/sys/fs/pstore``) and can be retrieved by userspace.
+
+On systemd systems, the ``systemd-pstore`` service will help do the following:
+
+#. Locate pstore data in ``/sys/fs/pstore``
+#. Read and save it to ``/var/lib/systemd/pstore``
+#. Clear pstore data for the next event

drivers/base/power/generic_ops.c

@@ -8,6 +8,13 @@
 #include <linux/pm_runtime.h>
 #include <linux/export.h>
 
+#define CALL_PM_OP(dev, op) \
+({ \
+	struct device *_dev = (dev); \
+	const struct dev_pm_ops *pm = _dev->driver ? _dev->driver->pm : NULL; \
+	pm && pm->op ? pm->op(_dev) : 0; \
+})
+
 #ifdef CONFIG_PM
 /**
  * pm_generic_runtime_suspend - Generic runtime suspend callback for subsystems.
@@ -19,12 +26,7 @@
  */
 int pm_generic_runtime_suspend(struct device *dev)
 {
-	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
-	int ret;
-
-	ret = pm && pm->runtime_suspend ? pm->runtime_suspend(dev) : 0;
-
-	return ret;
+	return CALL_PM_OP(dev, runtime_suspend);
 }
 EXPORT_SYMBOL_GPL(pm_generic_runtime_suspend);
 
@@ -38,12 +40,7 @@ EXPORT_SYMBOL_GPL(pm_generic_runtime_suspend);
  */
 int pm_generic_runtime_resume(struct device *dev)
 {
-	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
-	int ret;
-
-	ret = pm && pm->runtime_resume ? pm->runtime_resume(dev) : 0;
-
-	return ret;
+	return CALL_PM_OP(dev, runtime_resume);
 }
 EXPORT_SYMBOL_GPL(pm_generic_runtime_resume);
 #endif /* CONFIG_PM */
@@ -72,9 +69,7 @@ int pm_generic_prepare(struct device *dev)
  */
 int pm_generic_suspend_noirq(struct device *dev)
 {
-	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
-
-	return pm && pm->suspend_noirq ? pm->suspend_noirq(dev) : 0;
+	return CALL_PM_OP(dev, suspend_noirq);
 }
 EXPORT_SYMBOL_GPL(pm_generic_suspend_noirq);
 
@@ -84,9 +79,7 @@ EXPORT_SYMBOL_GPL(pm_generic_suspend_noirq);
  */
 int pm_generic_suspend_late(struct device *dev)
 {
-	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
-
-	return pm && pm->suspend_late ? pm->suspend_late(dev) : 0;
+	return CALL_PM_OP(dev, suspend_late);
 }
 EXPORT_SYMBOL_GPL(pm_generic_suspend_late);
 
@@ -96,9 +89,7 @@ EXPORT_SYMBOL_GPL(pm_generic_suspend_late);
  */
 int pm_generic_suspend(struct device *dev)
 {
-	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
-
-	return pm && pm->suspend ? pm->suspend(dev) : 0;
+	return CALL_PM_OP(dev, suspend);
 }
 EXPORT_SYMBOL_GPL(pm_generic_suspend);
 
@@ -108,9 +99,7 @@ EXPORT_SYMBOL_GPL(pm_generic_suspend);
  */
 int pm_generic_freeze_noirq(struct device *dev)
 {
-	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
-
-	return pm && pm->freeze_noirq ? pm->freeze_noirq(dev) : 0;
+	return CALL_PM_OP(dev, freeze_noirq);
 }
 EXPORT_SYMBOL_GPL(pm_generic_freeze_noirq);
 
@@ -120,9 +109,7 @@ EXPORT_SYMBOL_GPL(pm_generic_freeze_noirq);
  */
 int pm_generic_freeze(struct device *dev)
 {
-	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
-
-	return pm && pm->freeze ? pm->freeze(dev) : 0;
+	return CALL_PM_OP(dev, freeze);
 }
 EXPORT_SYMBOL_GPL(pm_generic_freeze);
 
@@ -132,9 +119,7 @@ EXPORT_SYMBOL_GPL(pm_generic_freeze);
  */
 int pm_generic_poweroff_noirq(struct device *dev)
 {
-	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
-
-	return pm && pm->poweroff_noirq ? pm->poweroff_noirq(dev) : 0;
+	return CALL_PM_OP(dev, poweroff_noirq);
 }
 EXPORT_SYMBOL_GPL(pm_generic_poweroff_noirq);
 
@@ -144,9 +129,7 @@ EXPORT_SYMBOL_GPL(pm_generic_poweroff_noirq);
  */
 int pm_generic_poweroff_late(struct device *dev)
 {
-	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
-
-	return pm && pm->poweroff_late ? pm->poweroff_late(dev) : 0;
+	return CALL_PM_OP(dev, poweroff_late);
 }
 EXPORT_SYMBOL_GPL(pm_generic_poweroff_late);
 
@@ -156,9 +139,7 @@ EXPORT_SYMBOL_GPL(pm_generic_poweroff_late);
  */
 int pm_generic_poweroff(struct device *dev)
 {
-	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
-
-	return pm && pm->poweroff ? pm->poweroff(dev) : 0;
+	return CALL_PM_OP(dev, poweroff);
 }
 EXPORT_SYMBOL_GPL(pm_generic_poweroff);
 
@@ -168,9 +149,7 @@ EXPORT_SYMBOL_GPL(pm_generic_poweroff);
  */
 int pm_generic_thaw_noirq(struct device *dev)
 {
-	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
-
-	return pm && pm->thaw_noirq ? pm->thaw_noirq(dev) : 0;
+	return CALL_PM_OP(dev, thaw_noirq);
 }
 EXPORT_SYMBOL_GPL(pm_generic_thaw_noirq);
 
@@ -180,9 +159,7 @@ EXPORT_SYMBOL_GPL(pm_generic_thaw_noirq);
  */
 int pm_generic_thaw(struct device *dev)
 {
-	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
-
-	return pm && pm->thaw ? pm->thaw(dev) : 0;
+	return CALL_PM_OP(dev, thaw);
 }
 EXPORT_SYMBOL_GPL(pm_generic_thaw);
 
@@ -192,9 +169,7 @@ EXPORT_SYMBOL_GPL(pm_generic_thaw);
  */
 int pm_generic_resume_noirq(struct device *dev)
 {
-	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
-
-	return pm && pm->resume_noirq ? pm->resume_noirq(dev) : 0;
+	return CALL_PM_OP(dev, resume_noirq);
 }
 EXPORT_SYMBOL_GPL(pm_generic_resume_noirq);
 
@@ -204,9 +179,7 @@ EXPORT_SYMBOL_GPL(pm_generic_resume_noirq);
  */
 int pm_generic_resume_early(struct device *dev)
 {
-	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
-
-	return pm && pm->resume_early ? pm->resume_early(dev) : 0;
+	return CALL_PM_OP(dev, resume_early);
 }
 EXPORT_SYMBOL_GPL(pm_generic_resume_early);
 
@@ -216,9 +189,7 @@ EXPORT_SYMBOL_GPL(pm_generic_resume_early);
  */
 int pm_generic_resume(struct device *dev)
 {
-	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
-
-	return pm && pm->resume ? pm->resume(dev) : 0;
+	return CALL_PM_OP(dev, resume);
 }
 EXPORT_SYMBOL_GPL(pm_generic_resume);
 
@@ -228,9 +199,7 @@ EXPORT_SYMBOL_GPL(pm_generic_resume);
  */
 int pm_generic_restore_noirq(struct device *dev)
 {
-	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
-
-	return pm && pm->restore_noirq ? pm->restore_noirq(dev) : 0;
+	return CALL_PM_OP(dev, restore_noirq);
 }
 EXPORT_SYMBOL_GPL(pm_generic_restore_noirq);
 
@@ -240,9 +209,7 @@ EXPORT_SYMBOL_GPL(pm_generic_restore_noirq);
  */
 int pm_generic_restore_early(struct device *dev)
 {
-	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
-
-	return pm && pm->restore_early ? pm->restore_early(dev) : 0;
+	return CALL_PM_OP(dev, restore_early);
 }
 EXPORT_SYMBOL_GPL(pm_generic_restore_early);
 
@@ -252,9 +219,7 @@ EXPORT_SYMBOL_GPL(pm_generic_restore_early);
  */
 int pm_generic_restore(struct device *dev)
 {
-	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
-
-	return pm && pm->restore ? pm->restore(dev) : 0;
+	return CALL_PM_OP(dev, restore);
 }
 EXPORT_SYMBOL_GPL(pm_generic_restore);
 

drivers/base/power/main.c

@@ -34,6 +34,7 @@
 #include <linux/cpufreq.h>
 #include <linux/devfreq.h>
 #include <linux/timer.h>
+#include <linux/nmi.h>
 
 #include "../base.h"
 #include "power.h"
@@ -95,6 +96,8 @@ static const char *pm_verb(int event)
 		return "restore";
 	case PM_EVENT_RECOVER:
 		return "recover";
+	case PM_EVENT_POWEROFF:
+		return "poweroff";
 	default:
 		return "(unknown PM event)";
 	}
@@ -367,6 +370,7 @@ static pm_callback_t pm_op(const struct dev_pm_ops *ops, pm_message_t state)
 	case PM_EVENT_FREEZE:
 	case PM_EVENT_QUIESCE:
 		return ops->freeze;
+	case PM_EVENT_POWEROFF:
 	case PM_EVENT_HIBERNATE:
 		return ops->poweroff;
 	case PM_EVENT_THAW:
@@ -401,6 +405,7 @@ static pm_callback_t pm_late_early_op(const struct dev_pm_ops *ops,
 	case PM_EVENT_FREEZE:
 	case PM_EVENT_QUIESCE:
 		return ops->freeze_late;
+	case PM_EVENT_POWEROFF:
 	case PM_EVENT_HIBERNATE:
 		return ops->poweroff_late;
 	case PM_EVENT_THAW:
@@ -435,6 +440,7 @@ static pm_callback_t pm_noirq_op(const struct dev_pm_ops *ops, pm_message_t stat
 	case PM_EVENT_FREEZE:
 	case PM_EVENT_QUIESCE:
 		return ops->freeze_noirq;
+	case PM_EVENT_POWEROFF:
 	case PM_EVENT_HIBERNATE:
 		return ops->poweroff_noirq;
 	case PM_EVENT_THAW:
@@ -515,6 +521,11 @@ struct dpm_watchdog {
 #define DECLARE_DPM_WATCHDOG_ON_STACK(wd) \
 	struct dpm_watchdog wd
 
+static bool __read_mostly dpm_watchdog_all_cpu_backtrace;
+module_param(dpm_watchdog_all_cpu_backtrace, bool, 0644);
+MODULE_PARM_DESC(dpm_watchdog_all_cpu_backtrace,
+		 "Backtrace all CPUs on DPM watchdog timeout");
+
 /**
  * dpm_watchdog_handler - Driver suspend / resume watchdog handler.
  * @t: The timer that PM watchdog depends on.
@@ -530,8 +541,12 @@ static void dpm_watchdog_handler(struct timer_list *t)
 	unsigned int time_left;
 
 	if (wd->fatal) {
+		unsigned int this_cpu = smp_processor_id();
+
 		dev_emerg(wd->dev, "**** DPM device timeout ****\n");
 		show_stack(wd->tsk, NULL, KERN_EMERG);
+		if (dpm_watchdog_all_cpu_backtrace)
+			trigger_allbutcpu_cpu_backtrace(this_cpu);
 		panic("%s %s: unrecoverable failure\n",
 			dev_driver_string(wd->dev), dev_name(wd->dev));
 	}

drivers/base/power/trace.c

@@ -238,10 +238,8 @@ int show_trace_dev_match(char *buf, size_t size)
 		unsigned int hash = hash_string(DEVSEED, dev_name(dev),
 						DEVHASH);
 		if (hash == value) {
-			int len = snprintf(buf, size, "%s\n",
+			int len = scnprintf(buf, size, "%s\n",
 					    dev_driver_string(dev));
-			if (len > size)
-				len = size;
 			buf += len;
 			ret += len;
 			size -= len;