linux.git/arch/csky/Kconfig, branch master

tracing: Remove redundant config HAVE_FTRACE_MCOUNT_RECORD

2025-07-23T00:15:56+00:00

Ftrace is tightly coupled with architecture specific code because it
requires the use of trampolines written in assembly. This means that when
a new feature or optimization is made, it must be done for all
architectures. To simplify the approach, CONFIG_HAVE_FTRACE_* configs are
added to denote which architecture has the new enhancement so that other
architectures can still function until they too have been updated.

The CONFIG_HAVE_FTRACE_MCOUNT was added to help simplify the
DYNAMIC_FTRACE work, but now every architecture that implements
DYNAMIC_FTRACE also has HAVE_FTRACE_MCOUNT set too, making it redundant
with the HAVE_DYNAMIC_FTRACE.

Remove the HAVE_FTRACE_MCOUNT config and use DYNAMIC_FTRACE directly where
applicable.

Link: https://lore.kernel.org/all/20250703154916.48e3ada7@gandalf.local.home/

Cc: Masami Hiramatsu 
Cc: Mathieu Desnoyers 
Cc: Mark Rutland 
Cc: Linus Torvalds 
Link: https://lore.kernel.org/20250704104838.27a18690@gandalf.local.home
Signed-off-by: Steven Rostedt (Google)

csky/vdso: Remove gettimeofday() and friends from VDSO

2024-11-02T11:37:32+00:00

The time-related VDSO functionality was introduced in 2021 in
commit 87f3248cdb9a ("csky: Reconstruct VDSO framework") and
commit 0d3b051adbb7 ("csky: Add VDSO with GENERIC_GETTIMEOFDAY, GENERIC_TIME_VSYSCALL, HAVE_GENERIC_VDSO").

However the corresponding aux-vector entry AT_SYSINFO_EHDR was never
wired up, making these functions impossible to test or use.

The VDSO itself is kept as it also provides rt_sigreturn which is
exposed differently to userspace.

Signed-off-by: Thomas Weißschuh 
Signed-off-by: Thomas Gleixner 
Link: https://lore.kernel.org/all/20241010-vdso-generic-base-v1-1-b64f0842d512@linutronix.de

csky: Emulate one-byte cmpxchg

2024-05-11T14:07:07+00:00

Use the new cmpxchg_emu_u8() to emulate one-byte cmpxchg() on csky.

[ paulmck: Apply kernel test robot feedback. ]
[ paulmck: Drop two-byte support per Arnd Bergmann feedback. ]

Co-developed-by: Yujie Liu 
Signed-off-by: Yujie Liu 
Signed-off-by: Paul E. McKenney 
Tested-by: Yujie Liu 
Reviewed-by: Guo Ren 
Cc: Arnd Bergmann 
Cc:

Merge tag 'mm-stable-2024-03-13-20-04' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2024-03-15T00:43:30+00:00

Pull MM updates from Andrew Morton:

- Sumanth Korikkar has taught s390 to allocate hotplug-time page frames
from hotplugged memory rather than only from main memory. Series
"implement "memmap on memory" feature on s390".

- More folio conversions from Matthew Wilcox in the series

"Convert memcontrol charge moving to use folios"
"mm: convert mm counter to take a folio"

- Chengming Zhou has optimized zswap's rbtree locking, providing
significant reductions in system time and modest but measurable
reductions in overall runtimes. The series is "mm/zswap: optimize the
scalability of zswap rb-tree".

- Chengming Zhou has also provided the series "mm/zswap: optimize zswap
lru list" which provides measurable runtime benefits in some
swap-intensive situations.

- And Chengming Zhou further optimizes zswap in the series "mm/zswap:
optimize for dynamic zswap_pools". Measured improvements are modest.

- zswap cleanups and simplifications from Yosry Ahmed in the series
"mm: zswap: simplify zswap_swapoff()".

- In the series "Add DAX ABI for memmap_on_memory", Vishal Verma has
contributed several DAX cleanups as well as adding a sysfs tunable to
control the memmap_on_memory setting when the dax device is
hotplugged as system memory.

- Johannes Weiner has added the large series "mm: zswap: cleanups",
which does that.

- More DAMON work from SeongJae Park in the series

"mm/damon: make DAMON debugfs interface deprecation unignorable"
"selftests/damon: add more tests for core functionalities and corner cases"
"Docs/mm/damon: misc readability improvements"
"mm/damon: let DAMOS feeds and tame/auto-tune itself"

- In the series "mm/mempolicy: weighted interleave mempolicy and sysfs
extension" Rakie Kim has developed a new mempolicy interleaving
policy wherein we allocate memory across nodes in a weighted fashion
rather than uniformly. This is beneficial in heterogeneous memory
environments appearing with CXL.

- Christophe Leroy has contributed some cleanup and consolidation work
against the ARM pagetable dumping code in the series "mm: ptdump:
Refactor CONFIG_DEBUG_WX and check_wx_pages debugfs attribute".

- Luis Chamberlain has added some additional xarray selftesting in the
series "test_xarray: advanced API multi-index tests".

- Muhammad Usama Anjum has reworked the selftest code to make its
human-readable output conform to the TAP ("Test Anything Protocol")
format. Amongst other things, this opens up the use of third-party
tools to parse and process out selftesting results.

- Ryan Roberts has added fork()-time PTE batching of THP ptes in the
series "mm/memory: optimize fork() with PTE-mapped THP". Mainly
targeted at arm64, this significantly speeds up fork() when the
process has a large number of pte-mapped folios.

- David Hildenbrand also gets in on the THP pte batching game in his
series "mm/memory: optimize unmap/zap with PTE-mapped THP". It
implements batching during munmap() and other pte teardown
situations. The microbenchmark improvements are nice.

- And in the series "Transparent Contiguous PTEs for User Mappings"
Ryan Roberts further utilizes arm's pte's contiguous bit ("contpte
mappings"). Kernel build times on arm64 improved nicely. Ryan's
series "Address some contpte nits" provides some followup work.

- In the series "mm/hugetlb: Restore the reservation" Breno Leitao has
fixed an obscure hugetlb race which was causing unnecessary page
faults. He has also added a reproducer under the selftest code.

- In the series "selftests/mm: Output cleanups for the compaction
test", Mark Brown did what the title claims.

- Kinsey Ho has added the series "mm/mglru: code cleanup and
refactoring".

- Even more zswap material from Nhat Pham. The series "fix and extend
zswap kselftests" does as claimed.

- In the series "Introduce cpu_dcache_is_aliasing() to fix DAX
regression" Mathieu Desnoyers has cleaned up and fixed rather a mess
in our handling of DAX on archiecctures which have virtually aliasing
data caches. The arm architecture is the main beneficiary.

- Lokesh Gidra's series "per-vma locks in userfaultfd" provides
dramatic improvements in worst-case mmap_lock hold times during
certain userfaultfd operations.

- Some page_owner enhancements and maintenance work from Oscar Salvador
in his series

"page_owner: print stacks and their outstanding allocations"
"page_owner: Fixup and cleanup"

- Uladzislau Rezki has contributed some vmalloc scalability
improvements in his series "Mitigate a vmap lock contention". It
realizes a 12x improvement for a certain microbenchmark.

- Some kexec/crash cleanup work from Baoquan He in the series "Split
crash out from kexec and clean up related config items".

- Some zsmalloc maintenance work from Chengming Zhou in the series

"mm/zsmalloc: fix and optimize objects/page migration"
"mm/zsmalloc: some cleanup for get/set_zspage_mapping()"

- Zi Yan has taught the MM to perform compaction on folios larger than
order=0. This a step along the path to implementaton of the merging
of large anonymous folios. The series is named "Enable >0 order folio
memory compaction".

- Christoph Hellwig has done quite a lot of cleanup work in the
pagecache writeback code in his series "convert write_cache_pages()
to an iterator".

- Some modest hugetlb cleanups and speedups in Vishal Moola's series
"Handle hugetlb faults under the VMA lock".

- Zi Yan has changed the page splitting code so we can split huge pages
into sizes other than order-0 to better utilize large folios. The
series is named "Split a folio to any lower order folios".

- David Hildenbrand has contributed the series "mm: remove
total_mapcount()", a cleanup.

- Matthew Wilcox has sought to improve the performance of bulk memory
freeing in his series "Rearrange batched folio freeing".

- Gang Li's series "hugetlb: parallelize hugetlb page init on boot"
provides large improvements in bootup times on large machines which
are configured to use large numbers of hugetlb pages.

- Matthew Wilcox's series "PageFlags cleanups" does that.

- Qi Zheng's series "minor fixes and supplement for ptdesc" does that
also. S390 is affected.

- Cleanups to our pagemap utility functions from Peter Xu in his series
"mm/treewide: Replace pXd_large() with pXd_leaf()".

- Nico Pache has fixed a few things with our hugepage selftests in his
series "selftests/mm: Improve Hugepage Test Handling in MM
Selftests".

- Also, of course, many singleton patches to many things. Please see
the individual changelogs for details.

* tag 'mm-stable-2024-03-13-20-04' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (435 commits)
mm/zswap: remove the memcpy if acomp is not sleepable
crypto: introduce: acomp_is_async to expose if comp drivers might sleep
memtest: use {READ,WRITE}_ONCE in memory scanning
mm: prohibit the last subpage from reusing the entire large folio
mm: recover pud_leaf() definitions in nopmd case
selftests/mm: skip the hugetlb-madvise tests on unmet hugepage requirements
selftests/mm: skip uffd hugetlb tests with insufficient hugepages
selftests/mm: dont fail testsuite due to a lack of hugepages
mm/huge_memory: skip invalid debugfs new_order input for folio split
mm/huge_memory: check new folio order when split a folio
mm, vmscan: retry kswapd's priority loop with cache_trim_mode off on failure
mm: add an explicit smp_wmb() to UFFDIO_CONTINUE
mm: fix list corruption in put_pages_list
mm: remove folio from deferred split list before uncharging it
filemap: avoid unnecessary major faults in filemap_fault()
mm,page_owner: drop unnecessary check
mm,page_owner: check for null stack_record before bumping its refcount
mm: swap: fix race between free_swap_and_cache() and swapoff()
mm/treewide: align up pXd_leaf() retval across archs
mm/treewide: drop pXd_large()
...

arch: define CONFIG_PAGE_SIZE_*KB on all architectures

2024-03-06T18:29:09+00:00

Most architectures only support a single hardcoded page size. In order
to ensure that each one of these sets the corresponding Kconfig symbols,
change over the PAGE_SHIFT definition to the common one and allow
only the hardware page size to be selected.

Acked-by: Guo Ren 
Acked-by: Heiko Carstens 
Acked-by: Stafford Horne 
Acked-by: Johannes Berg 
Acked-by: Geert Uytterhoeven 
Reviewed-by: Thomas Gleixner 
Signed-off-by: Arnd Bergmann

Introduce cpu_dcache_is_aliasing() across all architectures

2024-02-22T23:27:19+00:00

Introduce a generic way to query whether the data cache is virtually
aliased on all architectures. Its purpose is to ensure that subsystems
which are incompatible with virtually aliased data caches (e.g. FS_DAX)
can reliably query this.

For data cache aliasing, there are three scenarios dependending on the
architecture. Here is a breakdown based on my understanding:

A) The data cache is always aliasing:

* arc
* csky
* m68k (note: shared memory mappings are incoherent ? SHMLBA is missing there.)
* sh
* parisc

B) The data cache aliasing is statically known or depends on querying CPU
   state at runtime:

* arm (cache_is_vivt() || cache_is_vipt_aliasing())
* mips (cpu_has_dc_aliases)
* nios2 (NIOS2_DCACHE_SIZE > PAGE_SIZE)
* sparc32 (vac_cache_size > PAGE_SIZE)
* sparc64 (L1DCACHE_SIZE > PAGE_SIZE)
* xtensa (DCACHE_WAY_SIZE > PAGE_SIZE)

C) The data cache is never aliasing:

* alpha
* arm64 (aarch64)
* hexagon
* loongarch (but with incoherent write buffers, which are disabled since
             commit d23b7795 ("LoongArch: Change SHMLBA from SZ_64K to PAGE_SIZE"))
* microblaze
* openrisc
* powerpc
* riscv
* s390
* um
* x86

Require architectures in A) and B) to select ARCH_HAS_CPU_CACHE_ALIASING and
implement "cpu_dcache_is_aliasing()".

Architectures in C) don't select ARCH_HAS_CPU_CACHE_ALIASING, and thus
cpu_dcache_is_aliasing() simply evaluates to "false".

Note that this leaves "cpu_icache_is_aliasing()" to be implemented as future
work. This would be useful to gate features like XIP on architectures
which have aliasing CPU dcache-icache but not CPU dcache-dcache.

Use "cpu_dcache" and "cpu_cache" rather than just "dcache" and "cache"
to clarify that we really mean "CPU data cache" and "CPU cache" to
eliminate any possible confusion with VFS "dentry cache" and "page
cache".

Link: https://lore.kernel.org/lkml/20030910210416.GA24258@mail.jlokier.co.uk/
Link: https://lkml.kernel.org/r/20240215144633.96437-9-mathieu.desnoyers@efficios.com
Fixes: d92576f1167c ("dax: does not work correctly with virtual aliasing caches")
Signed-off-by: Mathieu Desnoyers 
Cc: Dan Williams 
Cc: Vishal Verma 
Cc: Dave Jiang 
Cc: Matthew Wilcox 
Cc: Arnd Bergmann 
Cc: Russell King 
Cc: Alasdair Kergon 
Cc: Christoph Hellwig 
Cc: Dave Chinner 
Cc: Heiko Carstens 
Cc: kernel test robot 
Cc: Michael Sclafani 
Cc: Mike Snitzer 
Cc: Mikulas Patocka 
Signed-off-by: Andrew Morton

Merge branch 'expand-stack'

2023-06-29T03:35:21+00:00

This modifies our user mode stack expansion code to always take the
mmap_lock for writing before modifying the VM layout.

It's actually something we always technically should have done, but
because we didn't strictly need it, we were being lazy ("opportunistic"
sounds so much better, doesn't it?) about things, and had this hack in
place where we would extend the stack vma in-place without doing the
proper locking.

And it worked fine.  We just needed to change vm_start (or, in the case
of grow-up stacks, vm_end) and together with some special ad-hoc locking
using the anon_vma lock and the mm->page_table_lock, it all was fairly
straightforward.

That is, it was all fine until Ruihan Li pointed out that now that the
vma layout uses the maple tree code, we *really* don't just change
vm_start and vm_end any more, and the locking really is broken.  Oops.

It's not actually all _that_ horrible to fix this once and for all, and
do proper locking, but it's a bit painful.  We have basically three
different cases of stack expansion, and they all work just a bit
differently:

 - the common and obvious case is the page fault handling. It's actually
   fairly simple and straightforward, except for the fact that we have
   something like 24 different versions of it, and you end up in a maze
   of twisty little passages, all alike.

 - the simplest case is the execve() code that creates a new stack.
   There are no real locking concerns because it's all in a private new
   VM that hasn't been exposed to anybody, but lockdep still can end up
   unhappy if you get it wrong.

 - and finally, we have GUP and page pinning, which shouldn't really be
   expanding the stack in the first place, but in addition to execve()
   we also use it for ptrace(). And debuggers do want to possibly access
   memory under the stack pointer and thus need to be able to expand the
   stack as a special case.

None of these cases are exactly complicated, but the page fault case in
particular is just repeated slightly differently many many times.  And
ia64 in particular has a fairly complicated situation where you can have
both a regular grow-down stack _and_ a special grow-up stack for the
register backing store.

So to make this slightly more manageable, the bulk of this series is to
first create a helper function for the most common page fault case, and
convert all the straightforward architectures to it.

Thus the new 'lock_mm_and_find_vma()' helper function, which ends up
being used by x86, arm, powerpc, mips, riscv, alpha, arc, csky, hexagon,
loongarch, nios2, sh, sparc32, and xtensa.  So we not only convert more
than half the architectures, we now have more shared code and avoid some
of those twisty little passages.

And largely due to this common helper function, the full diffstat of
this series ends up deleting more lines than it adds.

That still leaves eight architectures (ia64, m68k, microblaze, openrisc,
parisc, s390, sparc64 and um) that end up doing 'expand_stack()'
manually because they are doing something slightly different from the
normal pattern.  Along with the couple of special cases in execve() and
GUP.

So there's a couple of patches that first create 'locked' helper
versions of the stack expansion functions, so that there's a obvious
path forward in the conversion.  The execve() case is then actually
pretty simple, and is a nice cleanup from our old "grow-up stackls are
special, because at execve time even they grow down".

The #ifdef CONFIG_STACK_GROWSUP in that code just goes away, because
it's just more straightforward to write out the stack expansion there
manually, instead od having get_user_pages_remote() do it for us in some
situations but not others and have to worry about locking rules for GUP.

And the final step is then to just convert the remaining odd cases to a
new world order where 'expand_stack()' is called with the mmap_lock held
for reading, but where it might drop it and upgrade it to a write, only
to return with it held for reading (in the success case) or with it
completely dropped (in the failure case).

In the process, we remove all the stack expansion from GUP (where
dropping the lock wouldn't be ok without special rules anyway), and add
it in manually to __access_remote_vm() for ptrace().

Thanks to Adrian Glaubitz and Frank Scheiner who tested the ia64 cases.
Everything else here felt pretty straightforward, but the ia64 rules for
stack expansion are really quite odd and very different from everything
else.  Also thanks to Vegard Nossum who caught me getting one of those
odd conditions entirely the wrong way around.

Anyway, I think I want to actually move all the stack expansion code to
a whole new file of its own, rather than have it split up between
mm/mmap.c and mm/memory.c, but since this will have to be backported to
the initial maple tree vma introduction anyway, I tried to keep the
patches _fairly_ minimal.

Also, while I don't think it's valid to expand the stack from GUP, the
final patch in here is a "warn if some crazy GUP user wants to try to
expand the stack" patch.  That one will be reverted before the final
release, but it's left to catch any odd cases during the merge window
and release candidates.

Reported-by: Ruihan Li 

* branch 'expand-stack':
  gup: add warning if some caller would seem to want stack expansion
  mm: always expand the stack with the mmap write lock held
  execve: expand new process stack manually ahead of time
  mm: make find_extend_vma() fail if write lock not held
  powerpc/mm: convert coprocessor fault to lock_mm_and_find_vma()
  mm/fault: convert remaining simple cases to lock_mm_and_find_vma()
  arm/mm: Convert to using lock_mm_and_find_vma()
  riscv/mm: Convert to using lock_mm_and_find_vma()
  mips/mm: Convert to using lock_mm_and_find_vma()
  powerpc/mm: Convert to using lock_mm_and_find_vma()
  arm64/mm: Convert to using lock_mm_and_find_vma()
  mm: make the page fault mmap locking killable
  mm: introduce new 'lock_mm_and_find_vma()' page fault helper

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

csky/smp: Switch to hotplug core state synchronization

2023-05-15T11:44:58+00:00

Switch to the CPU hotplug core state tracking and synchronization
mechanim. No functional change intended.

Signed-off-by: Thomas Gleixner 
Signed-off-by: Peter Zijlstra (Intel) 
Tested-by: Michael Kelley 
Tested-by: Oleksandr Natalenko 
Tested-by: Helge Deller  # parisc
Tested-by: Guilherme G. Piccoli  # Steam Deck
Link: https://lore.kernel.org/r/20230512205256.747254502@linutronix.de

Merge tag 'csky-for-linus-6.4' of https://github.com/c-sky/csky-linux

2023-05-04T19:25:05+00:00

Pull arch/csky updates from Guo Ren:

 - Remove CPU_TLB_SIZE config

 - Prevent spurious page faults

* tag 'csky-for-linus-6.4' of https://github.com/c-sky/csky-linux:
  csky: mmu: Prevent spurious page faults
  csky: remove obsolete config CPU_TLB_SIZE