The commit introducing this function implemented it as a build bug on this platform to make the compiler happy, as the only use in the code is guarded behind a radix_enabled() conditional.
GCC recognises that cpu_has_feature(MMU_FTR_TYPE_RADIX) returns false on this platform and eliminates the build bug as dead code. However, when CONFIG_JUMP_LABEL_FEATURE_CHECK_DEBUG is enabled, the assertion and possible call to early_cpu_... prevents Clang from eliminating any code that's conditional on the return value. So Clang triggers the build bug as reported by the kernel test robot: https://lore.kernel.org/llvm/202301212348.edkowvff-...@intel.com Fixes: 274d842fa1ef ("powerpc/tlb: Add local flush for page given mm_struct and psize") Reported-by: kernel test robot <l...@intel.com> Signed-off-by: Benjamin Gray <bg...@linux.ibm.com> --- Supersedes https://patchwork.ozlabs.org/project/linuxppc-dev/patch/20230124215424.9068-1-bg...@linux.ibm.com/ --- arch/powerpc/include/asm/book3s/32/tlbflush.h | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/arch/powerpc/include/asm/book3s/32/tlbflush.h b/arch/powerpc/include/asm/book3s/32/tlbflush.h index 4be572908124..cde3b6f5d563 100644 --- a/arch/powerpc/include/asm/book3s/32/tlbflush.h +++ b/arch/powerpc/include/asm/book3s/32/tlbflush.h @@ -2,8 +2,6 @@ #ifndef _ASM_POWERPC_BOOK3S_32_TLBFLUSH_H #define _ASM_POWERPC_BOOK3S_32_TLBFLUSH_H -#include <linux/build_bug.h> - #define MMU_NO_CONTEXT (0) /* * TLB flushing for "classic" hash-MMU 32-bit CPUs, 6xx, 7xx, 7xxx @@ -80,7 +78,7 @@ static inline void local_flush_tlb_page(struct vm_area_struct *vma, static inline void local_flush_tlb_page_psize(struct mm_struct *mm, unsigned long vmaddr, int psize) { - BUILD_BUG(); + flush_range(mm, vmaddr, vmaddr + PAGE_SIZE); } static inline void local_flush_tlb_mm(struct mm_struct *mm) base-commit: ca272751ba18ca8f137af631cbc9f3f987fab6e3 -- 2.39.1
