linux/arch/arc/include, branch v6.8

work around gcc bugs with 'asm goto' with outputs

2024-02-09T23:57:48Z

We've had issues with gcc and 'asm goto' before, and we created a 'asm_volatile_goto()' macro for that in the past: see commits 3f0116c3238a ("compiler/gcc4: Add quirk for 'asm goto' miscompilation bug") and a9f180345f53 ("compiler/gcc4: Make quirk for asm_volatile_goto() unconditional"). Then, much later, we ended up removing the workaround in commit 43c249ea0b1e ("compiler-gcc.h: remove ancient workaround for gcc PR 58670") because we no longer supported building the kernel with the affected gcc versions, but we left the macro uses around. Now, Sean Christopherson reports a new version of a very similar problem, which is fixed by re-applying that ancient workaround. But the problem in question is limited to only the 'asm goto with outputs' cases, so instead of re-introducing the old workaround as-is, let's rename and limit the workaround to just that much less common case. It looks like there are at least two separate issues that all hit in this area: (a) some versions of gcc don't mark the asm goto as 'volatile' when it has outputs: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98619 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110420 which is easy to work around by just adding the 'volatile' by hand. (b) Internal compiler errors: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110422 which are worked around by adding the extra empty 'asm' as a barrier, as in the original workaround. but the problem Sean sees may be a third thing since it involves bad code generation (not an ICE) even with the manually added 'volatile'. but the same old workaround works for this case, even if this feels a bit like voodoo programming and may only be hiding the issue. Reported-and-tested-by: Sean Christopherson Link: https://lore.kernel.org/all/20240208220604.140859-1-seanjc@google.com/ Cc: Nick Desaulniers Cc: Uros Bizjak Cc: Jakub Jelinek Cc: Andrew Pinski Signed-off-by: Linus Torvalds

Merge tag 'percpu-for-6.8' of git://git.kernel.org/pub/scm/linux/kernel/git/dennis/percpu

2024-01-18T23:01:28Z

Pull percpu updates from Dennis Zhou: "Enable percpu page allocator for RISC-V. There are RISC-V configurations with sparse NUMA configurations and small vmalloc space causing dynamic percpu allocations to fail as the backing chunk stride is too far apart" * tag 'percpu-for-6.8' of git://git.kernel.org/pub/scm/linux/kernel/git/dennis/percpu: riscv: Enable pcpu page first chunk allocator mm: Introduce flush_cache_vmap_early()

Merge tag 'asm-generic-6.8' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic

2024-01-11T02:13:44Z

Pull asm-generic cleanups from Arnd Bergmann: "A series from Baoquan He cleans up the asm-generic/io.h to remove the ioremap_uc() definition from everything except x86, which still needs it for pre-PAT systems. This series notably contains a patch from Jiaxun Yang that converts MIPS to use asm-generic/io.h like every other architecture does, enabling future cleanups. Some of my own patches fix -Wmissing-prototype warnings in architecture specific code across several architectures. This is now needed as the warning is enabled by default. There are still some remaining warnings in minor platforms, but the series should catch most of the widely used ones make them more consistent with one another. David McKay fixes a bug in __generic_cmpxchg_local() when this is used on 64-bit architectures. This could currently only affect parisc64 and sparc64. Additional cleanups address from Linus Walleij, Uwe Kleine-König, Thomas Huth, and Kefeng Wang help reduce unnecessary inconsistencies between architectures" * tag 'asm-generic-6.8' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic: asm-generic: Fix 32 bit __generic_cmpxchg_local Hexagon: Make pfn accessors statics inlines ARC: mm: Make virt_to_pfn() a static inline mips: remove extraneous asm-generic/iomap.h include sparc: Use $(kecho) to announce kernel images being ready arm64: vdso32: Define BUILD_VDSO32_64 to correct prototypes csky: fix arch_jump_label_transform_static override arch: add do_page_fault prototypes arch: add missing prepare_ftrace_return() prototypes arch: vdso: consolidate gettime prototypes arch: include linux/cpu.h for trap_init() prototype arch: fix asm-offsets.c building with -Wmissing-prototypes arch: consolidate arch_irq_work_raise prototypes hexagon: Remove CONFIG_HEXAGON_ARCH_VERSION from uapi header asm/io: remove unnecessary xlate_dev_mem_ptr() and unxlate_dev_mem_ptr() mips: io: remove duplicated codes arch/*/io.h: remove ioremap_uc in some architectures mips: add including

mm: Introduce flush_cache_vmap_early()

2023-12-14T08:23:17Z

The pcpu setup when using the page allocator sets up a new vmalloc mapping very early in the boot process, so early that it cannot use the flush_cache_vmap() function which may depend on structures not yet initialized (for example in riscv, we currently send an IPI to flush other cpus TLB). But on some architectures, we must call flush_cache_vmap(): for example, in riscv, some uarchs can cache invalid TLB entries so we need to flush the new established mapping to avoid taking an exception. So fix this by introducing a new function flush_cache_vmap_early() which is called right after setting the new page table entry and before accessing this new mapping. This new function implements a local flush tlb on riscv and is no-op for other architectures (same as today). Signed-off-by: Alexandre Ghiti Acked-by: Geert Uytterhoeven Signed-off-by: Dennis Zhou

ARC: add hugetlb definitions

2023-12-14T03:33:10Z

Add hugetlb definitions if THP enabled. ARC doesn't support HugeTLB FS but it supports THP. Some kernel code such as pagemap uses hugetlb definitions with THP. This patch fixes ARC build issue (HPAGE_SIZE undeclared error) with TRANSPARENT_HUGEPAGE enabled. Signed-off-by: Pavel Kozlov Signed-off-by: Vineet Gupta

ARC: mm: retire support for aliasing VIPT D$

2023-12-09T00:30:24Z

Legacy ARC700 processors (first generation of MMU enabled ARC cores) had VIPT cached which could be configured such that they could alias. Corresponding support in kernel (with all the obnoxious cache flush overhead) was added in ARC port 10 years ago to support 1 silicon. That is long bygone and we can let it RIP. Cc: Matthew Wilcox (Oracle) Signed-off-by: Vineet Gupta

ARC: entry: move ARCompact specific bits out of entry.h

2023-12-09T00:30:24Z

- PUSHAUX/POPAUX helpers to ARCompact entry - use gas provided "push"/pop pseudo instructions Signed-off-by: Vineet Gupta

ARC: entry: SAVE_ABI_CALLEE_REG: ISA/ABI specific helper

2023-12-09T00:30:24Z

And for ARcompact variant replace the PUSH/POP macros with gas provided push/pop pseudo-instructions This allows ISA specific implementation e.g. Current ARCv2 PUSH/POP could be replaced with STD/LDL to save 2 registers at a time (w/o bothering with SP update each time) or perhaps use ENTER_S/LEAVE_S to reduce code size For ARCv3 ABI changed so callee regs are now r14-r26 (vs. r13-r25) thus would need a different implementation. Signed-off-by: Vineet Gupta

ARC: mm: Make virt_to_pfn() a static inline

2023-12-05T12:11:37Z

Making virt_to_pfn() a static inline taking a strongly typed (const void *) makes the contract of a passing a pointer of that type to the function explicit and exposes any misuse of the macro virt_to_pfn() acting polymorphic and accepting many types such as (void *), (unitptr_t) or (unsigned long) as arguments without warnings. In order to do this we move the virt_to_phys() and below the definition of the __pa() and __va() macros so it compiles. The macro version was also able to do recursive symbol resolution. Signed-off-by: Linus Walleij Signed-off-by: Arnd Bergmann

kprobes: unify kprobes_exceptions_nofify() prototypes

2023-11-10T10:59:05Z

Most architectures that support kprobes declare this function in their own asm/kprobes.h header and provide an override, but some are missing the prototype, which causes a warning for the __weak stub implementation: kernel/kprobes.c:1865:12: error: no previous prototype for 'kprobe_exceptions_notify' [-Werror=missing-prototypes] 1865 | int __weak kprobe_exceptions_notify(struct notifier_block *self, Move the prototype into linux/kprobes.h so it is visible to all the definitions. Link: https://lore.kernel.org/all/20231108125843.3806765-4-arnd@kernel.org/ Acked-by: Masami Hiramatsu (Google) Signed-off-by: Arnd Bergmann Signed-off-by: Masami Hiramatsu (Google)