kernel/linux.git/arch/arc, 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

arch: Add the macro COMPILE_OFFSETS to all the asm-offsets.c

2025-11-02T13:15:22+00:00

[ Upstream commit 35561bab768977c9e05f1f1a9bc00134c85f3e28 ] The include/generated/asm-offsets.h is generated in Kbuild during compiling from arch/SRCARCH/kernel/asm-offsets.c. When we want to generate another similar offset header file, circular dependency can happen. For example, we want to generate a offset file include/generated/test.h, which is included in include/sched/sched.h. If we generate asm-offsets.h first, it will fail, as include/sched/sched.h is included in asm-offsets.c and include/generated/test.h doesn't exist; If we generate test.h first, it can't success neither, as include/generated/asm-offsets.h is included by it. In x86_64, the macro COMPILE_OFFSETS is used to avoid such circular dependency. We can generate asm-offsets.h first, and if the COMPILE_OFFSETS is defined, we don't include the "generated/test.h". And we define the macro COMPILE_OFFSETS for all the asm-offsets.c for this purpose. Signed-off-by: Menglong Dong Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Sasha Levin

ARC: build: Try to guess GCC variant of cross compiler

2025-01-09T12:33:47+00:00

[ Upstream commit 824927e88456331c7a999fdf5d9d27923b619590 ] ARC GCC compiler is packaged starting from Fedora 39i and the GCC variant of cross compile tools has arc-linux-gnu- prefix and not arc-linux-. This is causing that CROSS_COMPILE variable is left unset. This change allows builds without need to supply CROSS_COMPILE argument if distro package is used. Before this change: $ make -j 128 ARCH=arc W=1 drivers/infiniband/hw/mlx4/ gcc: warning: ‘-mcpu=’ is deprecated; use ‘-mtune=’ or ‘-march=’ instead gcc: error: unrecognized command-line option ‘-mmedium-calls’ gcc: error: unrecognized command-line option ‘-mlock’ gcc: error: unrecognized command-line option ‘-munaligned-access’ [1] https://packages.fedoraproject.org/pkgs/cross-gcc/gcc-arc-linux-gnu/index.html Signed-off-by: Leon Romanovsky Signed-off-by: Vineet Gupta Signed-off-by: Sasha Levin

ARC: bpf: Correct conditional check in 'check_jmp_32'

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

[ Upstream commit 7dd9eb6ba88964b091b89855ce7d2a12405013af ] The original code checks 'if (ARC_CC_AL)', which is always true since ARC_CC_AL is a constant. This makes the check redundant and likely obscures the intention of verifying whether the jump is conditional. Updates the code to check cond == ARC_CC_AL instead, reflecting the intent to differentiate conditional from unconditional jumps. Suggested-by: Vadim Fedorenko Reviewed-by: Vadim Fedorenko Acked-by: Shahab Vahedi Signed-off-by: Hardevsinh Palaniya Signed-off-by: Vineet Gupta 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

ARC: build: disallow invalid PAE40 + 4K page config

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

[ Upstream commit 8871331b1769978ecece205a430338a2581e5050 ] The config option being built was | CONFIG_ARC_MMU_V4=y | CONFIG_ARC_PAGE_SIZE_4K=y | CONFIG_HIGHMEM=y | CONFIG_ARC_HAS_PAE40=y This was hitting a BUILD_BUG_ON() since a 4K page can't hoist 1k, 8-byte PTE entries (8 byte due to PAE40). BUILD_BUG_ON() is a good last ditch resort, but such a config needs to be disallowed explicitly in Kconfig. Side-note: the actual fix is single liner dependency, but while at it cleaned out a few things: - 4K dependency on MMU v3 or v4 is always true, since 288ff7de62af09 ("ARC: retire MMUv1 and MMUv2 support") - PAE40 dependency in on MMU ver not really ISA, although that follows eventually. Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-kbuild-all/202409160223.xydgucbY-lkp@intel.com/ Signed-off-by: Vineet Gupta Signed-off-by: Sasha Levin

of/fdt: add dt_phys arg to early_init_dt_scan and early_init_dt_verify

2024-12-05T13:01:32+00:00

[ Upstream commit b2473a359763e27567993e7d8f37de82f57a0829 ] __pa() is only intended to be used for linear map addresses and using it for initial_boot_params which is in fixmap for arm64 will give an incorrect value. Hence save the physical address when it is known at boot time when calling early_init_dt_scan for arm64 and use it at kexec time instead of converting the virtual address using __pa(). Note that arm64 doesn't need the FDT region reserved in the DT as the kernel explicitly reserves the passed in FDT. Therefore, only a debug warning is fixed with this change. Reported-by: Breno Leitao Suggested-by: Mark Rutland Signed-off-by: Usama Arif Fixes: ac10be5cdbfa ("arm64: Use common of_kexec_alloc_and_setup_fdt()") Link: https://lore.kernel.org/r/20241023171426.452688-1-usamaarif642@gmail.com Signed-off-by: Rob Herring (Arm) 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

Merge tag 'kbuild-v6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

2024-09-24T20:02:06+00:00

Pull Kbuild updates from Masahiro Yamada: - Support cross-compiling linux-headers Debian package and kernel-devel RPM package - Add support for the linux-debug Pacman package - Improve module rebuilding speed by factoring out the common code to scripts/module-common.c - Separate device tree build rules into scripts/Makefile.dtbs - Add a new script to generate modules.builtin.ranges, which is useful for tracing tools to find symbols in built-in modules - Refactor Kconfig and misc tools - Update Kbuild and Kconfig documentation * tag 'kbuild-v6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (51 commits) kbuild: doc: replace "gcc" in external module description kbuild: doc: describe the -C option precisely for external module builds kbuild: doc: remove the description about shipped files kbuild: doc: drop section numbering, use references in modules.rst kbuild: doc: throw out the local table of contents in modules.rst kbuild: doc: remove outdated description of the limitation on -I usage kbuild: doc: remove description about grepping CONFIG options kbuild: doc: update the description about Kbuild/Makefile split kbuild: remove unnecessary export of RUST_LIB_SRC kbuild: remove append operation on cmd_ld_ko_o kconfig: cache expression values kconfig: use hash table to reuse expressions kconfig: refactor expr_eliminate_dups() kconfig: add comments to expression transformations kconfig: change some expr_*() functions to bool scripts: move hash function from scripts/kconfig/ to scripts/include/ kallsyms: change overflow variable to bool type kallsyms: squash output_address() kbuild: add install target for modules.builtin.ranges scripts: add verifier script for builtin module range data ...

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

arc: Fix __fls() const-foldability via __builtin_clzl()

arch: Add the macro COMPILE_OFFSETS to all the asm-offsets.c

ARC: build: Try to guess GCC variant of cross compiler

ARC: bpf: Correct conditional check in 'check_jmp_32'

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

ARC: build: disallow invalid PAE40 + 4K page config

of/fdt: add dt_phys arg to early_init_dt_scan and early_init_dt_verify

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

arc: get rid of private asm/unaligned.h

Merge tag 'kbuild-v6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

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