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()
  ...

4 files changed, 80 insertions, 0 deletions

diff --git a/Documentation/ABI/testing/sysfs-power b/Documentation/ABI/testing/sysfs-power
index 4d8e1ad020f0..d38da077905a 100644
--- a/Documentation/ABI/testing/sysfs-power
+++ b/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
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 6c42061ca20e..46db3cbb838f 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/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
diff --git a/Documentation/power/index.rst b/Documentation/power/index.rst
index a0f5244fb427..ea70633d9ce6 100644
--- a/Documentation/power/index.rst
+++ b/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
diff --git a/Documentation/power/shutdown-debugging.rst b/Documentation/power/shutdown-debugging.rst
new file mode 100644
index 000000000000..c510122e0bbc
--- /dev/null
+++ b/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