linux-toradex.git/arch/csky/mm, branch master

arch, mm: consolidate empty_zero_page

2026-04-05T20:53:01+00:00

Reduce 22 declarations of empty_zero_page to 3 and 23 declarations of
ZERO_PAGE() to 4.

Every architecture defines empty_zero_page that way or another, but for the
most of them it is always a page aligned page in BSS and most definitions
of ZERO_PAGE do virt_to_page(empty_zero_page).

Move Linus vetted x86 definition of empty_zero_page and ZERO_PAGE() to the
core MM and drop these definitions in architectures that do not implement
colored zero page (MIPS and s390).

ZERO_PAGE() remains a macro because turning it to a wrapper for a static
inline causes severe pain in header dependencies.

For the most part the change is mechanical, with these being noteworthy:

* alpha: aliased empty_zero_page with ZERO_PGE that was also used for boot
  parameters. Switching to a generic empty_zero_page removes the aliasing
  and keeps ZERO_PGE for boot parameters only
* arm64: uses __pa_symbol() in ZERO_PAGE() so that definition of
  ZERO_PAGE() is kept intact.
* m68k/parisc/um: allocated empty_zero_page from memblock,
  although they do not support zero page coloring and having it in BSS
  will work fine.
* sparc64 can have empty_zero_page in BSS rather allocate it, but it
  can't use virt_to_page() for BSS. Keep it's definition of ZERO_PAGE()
  but instead of allocating it, make mem_map_zero point to
  empty_zero_page.
* sh: used empty_zero_page for boot parameters at the very early boot.
  Rename the parameters page to boot_params_page and let sh use the generic
  empty_zero_page.
* hexagon: had an amusing comment about empty_zero_page

	/* A handy thing to have if one has the RAM. Declared in head.S */

  that unfortunately had to go :)

Link: https://lkml.kernel.org/r/20260211103141.3215197-4-rppt@kernel.org
Signed-off-by: Mike Rapoport (Microsoft) 
Acked-by: Helge Deller 		[parisc]
Tested-by: Helge Deller 		[parisc]
Reviewed-by: Christophe Leroy (CS GROUP) 
Acked-by: Dave Hansen 
Acked-by: Catalin Marinas 
Acked-by: Magnus Lindholm 	[alpha]
Acked-by: Dinh Nguyen 	[nios2]
Acked-by: Andreas Larsson 	[sparc]
Acked-by: David Hildenbrand (Arm) 
Acked-by: Liam R. Howlett 
Cc: "Borislav Petkov (AMD)" 
Cc: David S. Miller 
Cc: Geert Uytterhoeven 
Cc: Guo Ren 
Cc: Huacai Chen 
Cc: Ingo Molnar 
Cc: Johannes Berg 
Cc: John Paul Adrian Glaubitz 
Cc: Lorenzo Stoakes 
Cc: Madhavan Srinivasan 
Cc: Matt Turner 
Cc: Max Filippov 
Cc: Michael Ellerman 
Cc: Michal Hocko 
Cc: Michal Simek 
Cc: Palmer Dabbelt 
Cc: Richard Weinberger 
Cc: Russell King 
Cc: Stafford Horne 
Cc: Suren Baghdasaryan 
Cc: Vineet Gupta 
Cc: Vlastimil Babka 
Cc: Will Deacon 
Signed-off-by: Andrew Morton

csky: fix csky_cmpxchg_fixup not working

2025-10-19T06:42:40+00:00

In the csky_cmpxchg_fixup function, it is incorrect to use the global
variable csky_cmpxchg_stw to determine the address where the exception
occurred.The global variable csky_cmpxchg_stw stores the opcode at the
time of the exception, while &csky_cmpxchg_stw shows the address where
the exception occurred.

Signed-off-by: Yang Li 
Signed-off-by: Guo Ren

csky: remove BS check for FAULT_FLAG_ALLOW_RETRY

2025-09-13T19:15:07+00:00

flags are initialized as FAULT_FLAG_DEFAULT, and the only thing done
to that afterwards is |=; since FAULT_FLAG_DEFAULT already includes
FAULT_FLAG_ALLOW_RETRY, it's guaranteed to remain there all along.

Reviewed-by: Guo Ren (Alibaba Damo Academy) 
Signed-off-by: Al Viro

arch, mm: make releasing of memory to page allocator more explicit

2025-03-18T05:06:53+00:00

The point where the memory is released from memblock to the buddy
allocator is hidden inside arch-specific mem_init()s and the call to
memblock_free_all() is needlessly duplicated in every artiste cure and
after introduction of arch_mm_preinit() hook, mem_init() implementation on
many architecture only contains the call to memblock_free_all().

Pull memblock_free_all() call into mm_core_init() and drop mem_init() on
relevant architectures to make it more explicit where the free memory is
released from memblock to the buddy allocator and to reduce code
duplication in architecture specific code.

Link: https://lkml.kernel.org/r/20250313135003.836600-14-rppt@kernel.org
Signed-off-by: Mike Rapoport (Microsoft) 
Acked-by: Dave Hansen 	[x86]
Acked-by: Geert Uytterhoeven 	[m68k]
Tested-by: Mark Brown 
Cc: Alexander Gordeev 
Cc: Andreas Larsson 
Cc: Andy Lutomirski 
Cc: Ard Biesheuvel 
Cc: Arnd Bergmann 
Cc: Borislav Betkov 
Cc: Catalin Marinas 
Cc: David S. Miller 
Cc: Dinh Nguyen 
Cc: Gerald Schaefer 
Cc: Guo Ren (csky) 
Cc: Heiko Carstens 
Cc: Helge Deller 
Cc: Huacai Chen 
Cc: Ingo Molnar 
Cc: Jiaxun Yang 
Cc: Johannes Berg 
Cc: John Paul Adrian Glaubitz 
Cc: Madhavan Srinivasan 
Cc: Matt Turner 
Cc: Max Filippov 
Cc: Michael Ellerman 
Cc: Michal Simek 
Cc: Palmer Dabbelt 
Cc: Richard Weinberger 
Cc: Russel King 
Cc: Stafford Horne 
Cc: Thomas Bogendoerfer 
Cc: Thomas Gleinxer 
Cc: Vasily Gorbik 
Cc: Vineet Gupta 
Cc: Will Deacon 
Signed-off-by: Andrew Morton

arch, mm: streamline HIGHMEM freeing

2025-03-18T05:06:53+00:00

All architectures that support HIGHMEM have their code that frees high
memory pages to the buddy allocator while __free_memory_core() is limited
to freeing only low memory.

There is no actual reason for that.  The memory map is completely ready by
the time memblock_free_all() is called and high pages can be released to
the buddy allocator along with low memory.

Remove low memory limit from __free_memory_core() and drop per-architecture
code that frees high memory pages.

Link: https://lkml.kernel.org/r/20250313135003.836600-12-rppt@kernel.org
Signed-off-by: Mike Rapoport (Microsoft) 
Acked-by: Dave Hansen 	[x86]
Tested-by: Mark Brown 
Cc: Alexander Gordeev 
Cc: Andreas Larsson 
Cc: Andy Lutomirski 
Cc: Ard Biesheuvel 
Cc: Arnd Bergmann 
Cc: Borislav Betkov 
Cc: Catalin Marinas 
Cc: David S. Miller 
Cc: Dinh Nguyen 
Cc: Geert Uytterhoeven 
Cc: Gerald Schaefer 
Cc: Guo Ren (csky) 
Cc: Heiko Carstens 
Cc: Helge Deller 
Cc: Huacai Chen 
Cc: Ingo Molnar 
Cc: Jiaxun Yang 
Cc: Johannes Berg 
Cc: John Paul Adrian Glaubitz 
Cc: Madhavan Srinivasan 
Cc: Matt Turner 
Cc: Max Filippov 
Cc: Michael Ellerman 
Cc: Michal Simek 
Cc: Palmer Dabbelt 
Cc: Richard Weinberger 
Cc: Russel King 
Cc: Stafford Horne 
Cc: Thomas Bogendoerfer 
Cc: Thomas Gleinxer 
Cc: Vasily Gorbik 
Cc: Vineet Gupta 
Cc: Will Deacon 
Signed-off-by: Andrew Morton

arch, mm: set high_memory in free_area_init()

2025-03-18T05:06:52+00:00

high_memory defines upper bound on the directly mapped memory.  This bound
is defined by the beginning of ZONE_HIGHMEM when a system has high memory
and by the end of memory otherwise.

All this is known to generic memory management initialization code that
can set high_memory while initializing core mm structures.

Add a generic calculation of high_memory to free_area_init() and remove
per-architecture calculation except for the architectures that set and use
high_memory earlier than that.

Link: https://lkml.kernel.org/r/20250313135003.836600-11-rppt@kernel.org
Signed-off-by: Mike Rapoport (Microsoft) 
Acked-by: Dave Hansen 	[x86]
Tested-by: Mark Brown 
Cc: Alexander Gordeev 
Cc: Andreas Larsson 
Cc: Andy Lutomirski 
Cc: Ard Biesheuvel 
Cc: Arnd Bergmann 
Cc: Borislav Betkov 
Cc: Catalin Marinas 
Cc: David S. Miller 
Cc: Dinh Nguyen 
Cc: Geert Uytterhoeven 
Cc: Gerald Schaefer 
Cc: Guo Ren (csky) 
Cc: Heiko Carstens 
Cc: Helge Deller 
Cc: Huacai Chen 
Cc: Ingo Molnar 
Cc: Jiaxun Yang 
Cc: Johannes Berg 
Cc: John Paul Adrian Glaubitz 
Cc: Madhavan Srinivasan 
Cc: Matt Turner 
Cc: Max Filippov 
Cc: Michael Ellerman 
Cc: Michal Simek 
Cc: Palmer Dabbelt 
Cc: Richard Weinberger 
Cc: Russel King 
Cc: Stafford Horne 
Cc: Thomas Bogendoerfer 
Cc: Thomas Gleinxer 
Cc: Vasily Gorbik 
Cc: Vineet Gupta 
Cc: Will Deacon 
Signed-off-by: Andrew Morton

arch, mm: set max_mapnr when allocating memory map for FLATMEM

2025-03-18T05:06:52+00:00

max_mapnr is essentially the size of the memory map for systems that use
FLATMEM. There is no reason to calculate it in each and every architecture
when it's anyway calculated in alloc_node_mem_map().

Drop setting of max_mapnr from architecture code and set it once in
alloc_node_mem_map().

While on it, move definition of mem_map and max_mapnr to mm/mm_init.c so
there won't be two copies for MMU and !MMU variants.

Link: https://lkml.kernel.org/r/20250313135003.836600-10-rppt@kernel.org
Signed-off-by: Mike Rapoport (Microsoft) 
Acked-by: Dave Hansen 	[x86]
Tested-by: Mark Brown 
Cc: Alexander Gordeev 
Cc: Andreas Larsson 
Cc: Andy Lutomirski 
Cc: Ard Biesheuvel 
Cc: Arnd Bergmann 
Cc: Borislav Betkov 
Cc: Catalin Marinas 
Cc: David S. Miller 
Cc: Dinh Nguyen 
Cc: Geert Uytterhoeven 
Cc: Gerald Schaefer 
Cc: Guo Ren (csky) 
Cc: Heiko Carstens 
Cc: Helge Deller 
Cc: Huacai Chen 
Cc: Ingo Molnar 
Cc: Jiaxun Yang 
Cc: Johannes Berg 
Cc: John Paul Adrian Glaubitz 
Cc: Madhavan Srinivasan 
Cc: Matt Turner 
Cc: Max Filippov 
Cc: Michael Ellerman 
Cc: Michal Simek 
Cc: Palmer Dabbelt 
Cc: Richard Weinberger 
Cc: Russel King 
Cc: Stafford Horne 
Cc: Thomas Bogendoerfer 
Cc: Thomas Gleinxer 
Cc: Vasily Gorbik 
Cc: Vineet Gupta 
Cc: Will Deacon 
Signed-off-by: Andrew Morton

csky: move setup_initrd() to setup.c

2025-03-18T05:06:51+00:00

Memory used by initrd should be reserved as soon as possible before
there any memblock allocations that might overwrite that memory.

This will also help with pulling out memblock_free_all() to the generic
code and reducing code duplication in arch::mem_init().

Link: https://lkml.kernel.org/r/20250313135003.836600-3-rppt@kernel.org
Signed-off-by: Mike Rapoport (Microsoft) 
Acked-by: Guo Ren (csky) 
Cc: Alexander Gordeev 
Cc: Andreas Larsson 
Cc: Andy Lutomirski 
Cc: Ard Biesheuvel 
Cc: Arnd Bergmann 
Cc: Borislav Betkov 
Cc: Catalin Marinas 
Cc: Dave Hansen 
Cc: David S. Miller 
Cc: Dinh Nguyen 
Cc: Geert Uytterhoeven 
Cc: Gerald Schaefer 
Cc: Heiko Carstens 
Cc: Helge Deller 
Cc: Huacai Chen 
Cc: Ingo Molnar 
Cc: Jiaxun Yang 
Cc: Johannes Berg 
Cc: John Paul Adrian Glaubitz 
Cc: Madhavan Srinivasan 
Cc: Mark Brown 
Cc: Matt Turner 
Cc: Max Filippov 
Cc: Michael Ellerman 
Cc: Michal Simek 
Cc: Palmer Dabbelt 
Cc: Richard Weinberger 
Cc: Russel King 
Cc: Stafford Horne 
Cc: Thomas Bogendoerfer 
Cc: Thomas Gleinxer 
Cc: Vasily Gorbik 
Cc: Vineet Gupta 
Cc: Will Deacon 
Signed-off-by: Andrew Morton

csky: fix up lock_mm_and_find_vma() conversion

2023-06-30T06:34:29+00:00

As already mentioned in my merge message for the 'expand-stack' branch,
we have something like 24 different versions of the page fault path for
all our different architectures, all just _slightly_ different due to
various historical reasons (usually related to exactly when they
branched off the original i386 version, and the details of the other
architectures they had in their history).

And a few of them had some silly mistake in the conversion.

Most of the architectures call the faulting address 'address' in the
fault path.  But not all.  Some just call it 'addr'.  And if you end up
doing a bit too much copy-and-paste, you end up with the wrong version
in the places that do it differently.

In this case it was csky.

Fixes: a050ba1e7422 ("mm/fault: convert remaining simple cases to lock_mm_and_find_vma()")
Reported-by: Guenter Roeck 
Signed-off-by: Linus Torvalds

mm/fault: convert remaining simple cases to lock_mm_and_find_vma()

2023-06-24T21:12:58+00:00

This does the simple pattern conversion of alpha, arc, csky, hexagon,
loongarch, nios2, sh, sparc32, and xtensa to the lock_mm_and_find_vma()
helper.  They all have the regular fault handling pattern without odd
special cases.

The remaining architectures all have something that keeps us from a
straightforward conversion: ia64 and parisc have stacks that can grow
both up as well as down (and ia64 has special address region checks).

And m68k, microblaze, openrisc, sparc64, and um end up having extra
rules about only expanding the stack down a limited amount below the
user space stack pointer.  That is something that x86 used to do too
(long long ago), and it probably could just be skipped, but it still
makes the conversion less than trivial.

Note that this conversion was done manually and with the exception of
alpha without any build testing, because I have a fairly limited cross-
building environment.  The cases are all simple, and I went through the
changes several times, but...

Signed-off-by: Linus Torvalds