kernel/linux.git/arch/arc/include, branch v6.12.80

arc: Fix fls() const-foldability via builtin_clzl()

2025-11-13T20:34:03+00:00

[ Upstream commit a3fecb9160482367365cc384c59dd220b162b066 ] While tracking down a problem where constant expressions used by BUILD_BUG_ON() suddenly stopped working[1], we found that an added static initializer was convincing the compiler that it couldn't track the state of the prior statically initialized value. Tracing this down found that ffs() was used in the initializer macro, but since it wasn't marked with __attribute__const__, the compiler had to assume the function might change variable states as a side-effect (which is not true for ffs(), which provides deterministic math results). For arc architecture with CONFIG_ISA_ARCV2=y, the __fls() function uses __builtin_arc_fls() which lacks GCC's const attribute, preventing compile-time constant folding, and KUnit testing of ffs/fls fails on arc[3]. A patch[2] to GCC to solve this has been sent. Add a fix for this by handling compile-time constants with the standard __builtin_clzl() builtin (which has const attribute) while preserving the optimized arc-specific builtin for runtime cases. This has the added benefit of skipping runtime calculation of compile-time constant values. Even with the GCC bug fixed (which is about "attribute const") this is a good change to avoid needless runtime costs, and should be done regardless of the state of GCC's bug. Build tested ARCH=arc allyesconfig with GCC arc-linux 15.2.0. Link: https://github.com/KSPP/linux/issues/364 [1] Link: https://gcc.gnu.org/pipermail/gcc-patches/2025-August/693273.html Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-kbuild-all/202508031025.doWxtzzc-lkp@intel.com/ [3] Signed-off-by: Kees Cook Acked-by: Vineet Gupta Signed-off-by: Yury Norov (NVIDIA) Signed-off-by: Sasha Levin

ARC: build: Use __force to suppress per-CPU cmpxchg warnings

2025-01-09T12:33:45+00:00

[ Upstream commit 1e8af9f04346ecc0bccf0c53b728fc8eb3490a28 ] Currently, the cast of the first argument to cmpxchg_emu_u8() drops the __percpu address-space designator, which results in sparse complaints when applying cmpxchg() to per-CPU variables in ARC. Therefore, use __force to suppress these complaints, given that this does not pertain to cmpxchg() semantics, which are plently well-defined on variables in general, whether per-CPU or otherwise. Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-kbuild-all/202409251336.ToC0TvWB-lkp@intel.com/ Signed-off-by: Paul E. McKenney Cc: Signed-off-by: Vineet Gupta Signed-off-by: Sasha Levin

move asm/unaligned.h to linux/unaligned.h

2024-10-02T21:23:23+00:00

asm/unaligned.h is always an include of asm-generic/unaligned.h; might as well move that thing to linux/unaligned.h and include that - there's nothing arch-specific in that header. auto-generated by the following: for i in `git grep -l -w asm/unaligned.h`; do sed -i -e "s/asm\/unaligned.h/linux\/unaligned.h/" $i done for i in `git grep -l -w asm-generic/unaligned.h`; do sed -i -e "s/asm-generic\/unaligned.h/linux\/unaligned.h/" $i done git mv include/asm-generic/unaligned.h include/linux/unaligned.h git mv tools/include/asm-generic/unaligned.h tools/include/linux/unaligned.h sed -i -e "/unaligned.h/d" include/asm-generic/Kbuild sed -i -e "s/__ASM_GENERIC/__LINUX/" include/linux/unaligned.h tools/include/linux/unaligned.h

arc: get rid of private asm/unaligned.h

2024-10-02T21:22:47+00:00

Declarations local to arch/*/kernel/*.c are better off *not* in a public header - arch/arc/kernel/unaligned.h is just fine for those bits. Unlike the parisc case, here we have an extra twist - asm/mmu.h has an implicit dependency on struct pt_regs, and in some users that used to be satisfied by include of asm/ptrace.h from asm/unaligned.h (note that asm/mmu.h itself did _not_ pull asm/unaligned.h - it relied upon the users having pulled asm/unaligned.h before asm/mmu.h got there). Seeing that asm/mmu.h only wants struct pt_regs * arguments in an extern, just pre-declare it there - less brittle that way. With that done _all_ asm/unaligned.h instances are reduced to include of asm-generic/unaligned.h and can be removed - unaligned.h is in mandatory-y in include/asm-generic/Kbuild. What's more, we can move asm-generic/unaligned.h to linux/unaligned.h and switch includes of to ; that's better off as an auto-generated commit, though, to be done by Linus at -rc1 time next cycle. Acked-by: Vineet Gupta Signed-off-by: Al Viro

ARC: Emulate one-byte cmpxchg

2024-09-13T14:10:37+00:00

Use the new cmpxchg_emu_u8() to emulate one-byte cmpxchg() on arc. [ paulmck: Drop two-byte support per Arnd Bergmann feedback. ] [ paulmck: Apply feedback from Naresh Kamboju. ] [ paulmck: Apply kernel test robot feedback. ] [ paulmck: Apply feedback from Vineet Gupta. ] Signed-off-by: Paul E. McKenney Cc: Andi Shyti Cc: Andrzej Hajda Cc: Arnd Bergmann Cc: Palmer Dabbelt Cc: Acked-by: Vineet Gupta

arc: convert to generic syscall table

2024-07-10T12:23:38+00:00

The uapi/asm/unistd_32.h and asm/syscall_table_32.h headers can now be generated from scripts/syscall.tbl, which makes this consistent with the other architectures that have their own syscall.tbl. arc has a couple of architecture specific system calls, which I add to the generic table. This for some reason includes the deprecated sys_sysfs() syscall that was presumably added by accident. The time32, renameat, stat64 and rlimit entries in the syscall_abis_32 entry are for system calls that were part of the generic ABI when arch/arc got added but are no longer enabled by default for new architectures. Both the user visible side of asm/unistd.h and the internal syscall table in the kernel should have the same effective contents after this. Signed-off-by: Arnd Bergmann

clone3: drop __ARCH_WANT_SYS_CLONE3 macro

2024-07-10T12:23:38+00:00

When clone3() was introduced, it was not obvious how each architecture deals with setting up the stack and keeping the register contents in a fork()-like system call, so this was left for the architecture maintainers to implement, with __ARCH_WANT_SYS_CLONE3 defined by those that already implement it. Five years later, we still have a few architectures left that are missing clone3(), and the macro keeps getting in the way as it's fundamentally different from all the other __ARCH_WANT_SYS_* macros that are meant to provide backwards-compatibility with applications using older syscalls that are no longer provided by default. Address this by reversing the polarity of the macro, adding an __ARCH_BROKEN_SYS_CLONE3 macro to all architectures that don't already provide the syscall, and remove __ARCH_WANT_SYS_CLONE3 from all the other ones. Acked-by: Geert Uytterhoeven Signed-off-by: Arnd Bergmann

Merge tag 'asm-generic-6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic

2024-05-20T22:18:34+00:00

Pull asm-generic cleanups from Arnd Bergmann: "These are a few cross-architecture cleanup patches: - separate out fbdev support from the asm/video.h contents that may be used by either the old fbdev drivers or the newer drm display code (Thomas Zimmermann) - cleanups for the generic bitops code and asm-generic/bug.h (Thorsten Blum) - remove the orphaned include/asm-generic/page.h header that used to be included by long-removed mmu-less architectures (me)" * tag 'asm-generic-6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic: arch: Fix name collision with ACPI's video.o bug: Improve comment asm-generic: remove unused asm-generic/page.h arch: Rename fbdev header and source files arch: Remove struct fb_info from video helpers arch: Select fbdev helpers with CONFIG_VIDEO bitops: Change function return types from long to int

Merge tag 'mm-stable-2024-05-17-19-19' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2024-05-19T16:21:03+00:00

Pull mm updates from Andrew Morton: "The usual shower of singleton fixes and minor series all over MM, documented (hopefully adequately) in the respective changelogs. Notable series include: - Lucas Stach has provided some page-mapping cleanup/consolidation/ maintainability work in the series "mm/treewide: Remove pXd_huge() API". - In the series "Allow migrate on protnone reference with MPOL_PREFERRED_MANY policy", Donet Tom has optimized mempolicy's MPOL_PREFERRED_MANY mode, yielding almost doubled performance in one test. - In their series "Memory allocation profiling" Kent Overstreet and Suren Baghdasaryan have contributed a means of determining (via /proc/allocinfo) whereabouts in the kernel memory is being allocated: number of calls and amount of memory. - Matthew Wilcox has provided the series "Various significant MM patches" which does a number of rather unrelated things, but in largely similar code sites. - In his series "mm: page_alloc: freelist migratetype hygiene" Johannes Weiner has fixed the page allocator's handling of migratetype requests, with resulting improvements in compaction efficiency. - In the series "make the hugetlb migration strategy consistent" Baolin Wang has fixed a hugetlb migration issue, which should improve hugetlb allocation reliability. - Liu Shixin has hit an I/O meltdown caused by readahead in a memory-tight memcg. Addressed in the series "Fix I/O high when memory almost met memcg limit". - In the series "mm/filemap: optimize folio adding and splitting" Kairui Song has optimized pagecache insertion, yielding ~10% performance improvement in one test. - Baoquan He has cleaned up and consolidated the early zone initialization code in the series "mm/mm_init.c: refactor free_area_init_core()". - Baoquan has also redone some MM initializatio code in the series "mm/init: minor clean up and improvement". - MM helper cleanups from Christoph Hellwig in his series "remove follow_pfn". - More cleanups from Matthew Wilcox in the series "Various page->flags cleanups". - Vlastimil Babka has contributed maintainability improvements in the series "memcg_kmem hooks refactoring". - More folio conversions and cleanups in Matthew Wilcox's series: "Convert huge_zero_page to huge_zero_folio" "khugepaged folio conversions" "Remove page_idle and page_young wrappers" "Use folio APIs in procfs" "Clean up __folio_put()" "Some cleanups for memory-failure" "Remove page_mapping()" "More folio compat code removal" - David Hildenbrand chipped in with "fs/proc/task_mmu: convert hugetlb functions to work on folis". - Code consolidation and cleanup work related to GUP's handling of hugetlbs in Peter Xu's series "mm/gup: Unify hugetlb, part 2". - Rick Edgecombe has developed some fixes to stack guard gaps in the series "Cover a guard gap corner case". - Jinjiang Tu has fixed KSM's behaviour after a fork+exec in the series "mm/ksm: fix ksm exec support for prctl". - Baolin Wang has implemented NUMA balancing for multi-size THPs. This is a simple first-cut implementation for now. The series is "support multi-size THP numa balancing". - Cleanups to vma handling helper functions from Matthew Wilcox in the series "Unify vma_address and vma_pgoff_address". - Some selftests maintenance work from Dev Jain in the series "selftests/mm: mremap_test: Optimizations and style fixes". - Improvements to the swapping of multi-size THPs from Ryan Roberts in the series "Swap-out mTHP without splitting". - Kefeng Wang has significantly optimized the handling of arm64's permission page faults in the series "arch/mm/fault: accelerate pagefault when badaccess" "mm: remove arch's private VM_FAULT_BADMAP/BADACCESS" - GUP cleanups from David Hildenbrand in "mm/gup: consistently call it GUP-fast". - hugetlb fault code cleanups from Vishal Moola in "Hugetlb fault path to use struct vm_fault". - selftests build fixes from John Hubbard in the series "Fix selftests/mm build without requiring "make headers"". - Memory tiering fixes/improvements from Ho-Ren (Jack) Chuang in the series "Improved Memory Tier Creation for CPUless NUMA Nodes". Fixes the initialization code so that migration between different memory types works as intended. - David Hildenbrand has improved follow_pte() and fixed an errant driver in the series "mm: follow_pte() improvements and acrn follow_pte() fixes". - David also did some cleanup work on large folio mapcounts in his series "mm: mapcount for large folios + page_mapcount() cleanups". - Folio conversions in KSM in Alex Shi's series "transfer page to folio in KSM". - Barry Song has added some sysfs stats for monitoring multi-size THP's in the series "mm: add per-order mTHP alloc and swpout counters". - Some zswap cleanups from Yosry Ahmed in the series "zswap same-filled and limit checking cleanups". - Matthew Wilcox has been looking at buffer_head code and found the documentation to be lacking. The series is "Improve buffer head documentation". - Multi-size THPs get more work, this time from Lance Yang. His series "mm/madvise: enhance lazyfreeing with mTHP in madvise_free" optimizes the freeing of these things. - Kemeng Shi has added more userspace-visible writeback instrumentation in the series "Improve visibility of writeback". - Kemeng Shi then sent some maintenance work on top in the series "Fix and cleanups to page-writeback". - Matthew Wilcox reduces mmap_lock traffic in the anon vma code in the series "Improve anon_vma scalability for anon VMAs". Intel's test bot reported an improbable 3x improvement in one test. - SeongJae Park adds some DAMON feature work in the series "mm/damon: add a DAMOS filter type for page granularity access recheck" "selftests/damon: add DAMOS quota goal test" - Also some maintenance work in the series "mm/damon/paddr: simplify page level access re-check for pageout" "mm/damon: misc fixes and improvements" - David Hildenbrand has disabled some known-to-fail selftests ni the series "selftests: mm: cow: flag vmsplice() hugetlb tests as XFAIL". - memcg metadata storage optimizations from Shakeel Butt in "memcg: reduce memory consumption by memcg stats". - DAX fixes and maintenance work from Vishal Verma in the series "dax/bus.c: Fixups for dax-bus locking"" * tag 'mm-stable-2024-05-17-19-19' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (426 commits) memcg, oom: cleanup unused memcg_oom_gfp_mask and memcg_oom_order selftests/mm: hugetlb_madv_vs_map: avoid test skipping by querying hugepage size at runtime mm/hugetlb: add missing VM_FAULT_SET_HINDEX in hugetlb_wp mm/hugetlb: add missing VM_FAULT_SET_HINDEX in hugetlb_fault selftests: cgroup: add tests to verify the zswap writeback path mm: memcg: make alloc_mem_cgroup_per_node_info() return bool mm/damon/core: fix return value from damos_wmark_metric_value mm: do not update memcg stats for NR_{FILE/SHMEM}_PMDMAPPED selftests: cgroup: remove redundant enabling of memory controller Docs/mm/damon/maintainer-profile: allow posting patches based on damon/next tree Docs/mm/damon/maintainer-profile: change the maintainer's timezone from PST to PT Docs/mm/damon/design: use a list for supported filters Docs/admin-guide/mm/damon/usage: fix wrong schemes effective quota update command Docs/admin-guide/mm/damon/usage: fix wrong example of DAMOS filter matching sysfs file selftests/damon: classify tests for functionalities and regressions selftests/damon/_damon_sysfs: use 'is' instead of '==' for 'None' selftests/damon/_damon_sysfs: find sysfs mount point from /proc/mounts selftests/damon/_damon_sysfs: check errors from nr_schemes file reads mm/damon/core: initialize ->esz_bp from damos_quota_init_priv() selftests/damon: add a test for DAMOS quota goal ...

arch: Rename fbdev header and source files

2024-05-03T15:07:50+00:00

The per-architecture fbdev code has no dependencies on fbdev and can be used for any video-related subsystem. Rename the files to 'video'. Use video-sti.c on parisc as the source file depends on CONFIG_STI_CORE. On arc, arm, arm64, sh, and um the asm header file is an empty wrapper around the file in asm-generic. Let Kbuild generate the file. The build system does this automatically. Only um needs to generate video.h explicitly, so that it overrides the host architecture's header. The latter would otherwise interfere with the build. Further update all includes statements, include guards, and Makefiles. Also update a few strings and comments to refer to video instead of fbdev. v3: - arc, arm, arm64, sh: generate asm header via build system (Sam, Helge, Arnd) - um: rename fb.h to video.h - fix typo in commit message (Sam) Signed-off-by: Thomas Zimmermann Reviewed-by: Sam Ravnborg Cc: Vineet Gupta Cc: Catalin Marinas Cc: Will Deacon Cc: Huacai Chen Cc: WANG Xuerui Cc: Geert Uytterhoeven Cc: Thomas Bogendoerfer Cc: "James E.J. Bottomley" Cc: Helge Deller Cc: Michael Ellerman Cc: Nicholas Piggin Cc: Yoshinori Sato Cc: Rich Felker Cc: John Paul Adrian Glaubitz Cc: "David S. Miller" Cc: Andreas Larsson Cc: Thomas Gleixner Cc: Ingo Molnar Cc: Borislav Petkov Cc: Dave Hansen Cc: x86@kernel.org Cc: "H. Peter Anvin" Signed-off-by: Arnd Bergmann