linux-toradex.git/kernel/power/snapshot.c, branch v6.19

PM: hibernate: Rework message printing in swsusp_save()

2025-10-20T18:43:09+00:00

The messages printed by swsusp_save() are basically only useful for
debug, so printing them every time a hibernation image is created at
the "info" log level is not particularly useful.  Also printing a
message on a failing memory allocation is redundant.

Use pm_deferred_pr_dbg() for printing those messages so they will only
be printed when requested and the "deferred" variant is used because
this code runs in a deeply atomic context (one CPU with interrupts
off, no functional devices).  Also drop the useless message printed
when memory allocations fails.

While at it, extend one of the messages in question so it is less
cryptic.

Signed-off-by: Rafael J. Wysocki 
[ rjw: Dropped a useless colon at the end of one of the messages ]
Link: https://patch.msgid.link/10750389.nUPlyArG6x@rafael.j.wysocki

PM: hibernate: Fix typo in memory bitmaps description comment

2025-09-01T09:55:53+00:00

Correct 'leave' to 'leaf' in memory bitmaps description comment.

Signed-off-by: Li Jun 
Link: https://patch.msgid.link/20250819104038.1596952-1-lijun01@kylinos.cn
[ rjw: Subject and changelog edits ]
Signed-off-by: Rafael J. Wysocki

PM: hibernate: Fix up white space that does not follow coding style

2025-07-17T18:30:52+00:00

Fix up white space usage that does not follow the kernel coding style
rules in several places in snapshot.c.

Signed-off-by: Darshan Rathod 
Link: https://patch.msgid.link/20250716124216.64329-1-darshanrathod475@gmail.com
[ rjw: New subject and changelog ]
Signed-off-by: Rafael J. Wysocki

mm, PM: use for_each_valid_pfn() in kernel/power/snapshot.c

2025-05-13T06:50:44+00:00

Link: https://lkml.kernel.org/r/20250423133821.789413-5-dwmw2@infradead.org
Signed-off-by: David Woodhouse 
Acked-by: Mike Rapoport (Microsoft) 
Cc: Anshuman Khandual 
Cc: Ard Biesheuvel 
Cc: Catalin Marinas 
Cc: David Hildenbrand 
Cc: Marc Rutland 
Cc: Marc Zyngier 
Cc: Ruihan Li 
Cc: Will Deacon 
Cc: Lorenzo Stoakes 
Signed-off-by: Andrew Morton

PM: hibernate: Replace deprecated kmap_atomic() with kmap_local_page()

2025-02-18T19:39:24+00:00

kmap_atomic() is deprecated and should be replaced with kmap_local_page()
[1][2]. kmap_local_page() is faster in kernels with HIGHMEM enabled, can
take page faults, and allows preemption.

According to [2], this replacement is safe as long as the code between
kmap_atomic() and kunmap_atomic() does not implicitly depend on disabling
page faults or preemption. In all of the call sites in this patch, the only
thing happening between mapping and unmapping pages is copy_page() calls,
and I don't suspect they depend on disabling page faults or preemption.

Link: https://lwn.net/Articles/836144/ [1]
Link: https://docs.kernel.org/mm/highmem.html#temporary-virtual-mappings [2]
Signed-off-by: David Reaver 
Link: https://patch.msgid.link/20250112152658.20132-1-me@davidreaver.com
Signed-off-by: Rafael J. Wysocki

mm/memblock: add memblock_alloc_or_panic interface

2025-01-26T04:22:38+00:00

Before SLUB initialization, various subsystems used memblock_alloc to
allocate memory.  In most cases, when memory allocation fails, an
immediate panic is required.  To simplify this behavior and reduce
repetitive checks, introduce `memblock_alloc_or_panic`.  This function
ensures that memory allocation failures result in a panic automatically,
improving code readability and consistency across subsystems that require
this behavior.

[guoweikang.kernel@gmail.com: arch/s390: save_area_alloc default failure behavior changed to panic]
  Link: https://lkml.kernel.org/r/20250109033136.2845676-1-guoweikang.kernel@gmail.com
  Link: https://lore.kernel.org/lkml/Z2fknmnNtiZbCc7x@kernel.org/
Link: https://lkml.kernel.org/r/20250102072528.650926-1-guoweikang.kernel@gmail.com
Signed-off-by: Guo Weikang 
Acked-by: Geert Uytterhoeven 	[m68k]
Reviewed-by: Alexander Gordeev 	[s390]
Acked-by: Mike Rapoport (Microsoft) 
Cc: Alexander Gordeev 
Signed-off-by: Andrew Morton

PM: hibernate: Remove unused stub for saveable_highmem_page()

2024-09-10T18:11:40+00:00

When saveable_highmem_page() is unused, it prevents kernel builds
with clang, `make W=1` and CONFIG_WERROR=y:

kernel/power/snapshot.c:1369:21: error: unused function 'saveable_highmem_page' [-Werror,-Wunused-function]
 1369 | static inline void *saveable_highmem_page(struct zone *z, unsigned long p)
      |                     ^~~~~~~~~~~~~~~~~~~~~

Fix this by removing unused stub.

See also commit 6863f5643dd7 ("kbuild: allow Clang to find unused static
inline functions for W=1 build").

Signed-off-by: Andy Shevchenko 
Link: https://patch.msgid.link/20240905184848.318978-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Rafael J. Wysocki

PM: hibernate: Don't ignore return from set_memory_ro()

2024-02-22T19:08:03+00:00

set_memory_ro() and set_memory_rw() can fail, leaving memory
unprotected.

Take the returned value into account and abort in case of
failure.

Signed-off-by: Christophe Leroy 
Reviewed-by: Kees Cook 
Signed-off-by: Rafael J. Wysocki

PM: hibernate: Use kmap_local_page() in copy_data_page()

2023-12-19T19:55:16+00:00

kmap_atomic() has been deprecated in favor of kmap_local_page().

kmap_atomic() disables page-faults and preemption (the latter
only for !PREEMPT_RT kernels).The code between the mapping and
un-mapping in this patch does not depend on the above-mentioned
side effects.So simply replaced kmap_atomic() with kmap_local_page().

Signed-off-by: Chen Haonan 
[ rjw: Subject edits ]
Signed-off-by: Rafael J. Wysocki

PM: hibernate: Do not initialize error in snapshot_write_next()

2023-12-11T21:09:52+00:00

The error variable in snapshot_write_next() gets a value before it is
used, so don't initialize it to 0 upfront.

Signed-off-by: Li zeming 
[ rjw: Subject and changelog rewrite ]
Signed-off-by: Rafael J. Wysocki