From 7908072da535dca52b3a011ed6e1f73534546b59 Mon Sep 17 00:00:00 2001 From: Fuad Tabba Date: Mon, 24 May 2021 09:29:48 +0100 Subject: [PATCH] arm64: Do not enable uaccess for invalidate_icache_range invalidate_icache_range() works on kernel addresses, and doesn't need uaccess. Remove the code that toggles uaccess_ttbr0_enable, as well as the code that emits an entry into the exception table (via the macro invalidate_icache_by_line). Changes return type of invalidate_icache_range() from int (which used to indicate a fault) to void, since it doesn't need uaccess and won't fault. Note that return value was never checked by any of the callers. No functional change intended. Possible performance impact due to the reduced number of instructions. Reported-by: Catalin Marinas Reported-by: Will Deacon Link: https://lore.kernel.org/linux-arch/20200511110014.lb9PEahJ4hVOYrbwIb_qUHXyNy9KQzNFdb_I3YlzY6A@z/ Acked-by: Mark Rutland Signed-off-by: Fuad Tabba Acked-by: Catalin Marinas Reviewed-by: Ard Biesheuvel Link: https://lore.kernel.org/r/20210524083001.2586635-6-tabba@google.com Signed-off-by: Will Deacon --- arch/arm64/include/asm/cacheflush.h | 2 +- arch/arm64/mm/cache.S | 11 +---------- 2 files changed, 2 insertions(+), 11 deletions(-) diff --git a/arch/arm64/include/asm/cacheflush.h b/arch/arm64/include/asm/cacheflush.h index 52e5c16..a586afa 100644 --- a/arch/arm64/include/asm/cacheflush.h +++ b/arch/arm64/include/asm/cacheflush.h @@ -57,7 +57,7 @@ * - size - region size */ extern void __flush_icache_range(unsigned long start, unsigned long end); -extern int invalidate_icache_range(unsigned long start, unsigned long end); +extern void invalidate_icache_range(unsigned long start, unsigned long end); extern void __flush_dcache_area(void *addr, size_t len); extern void __inval_dcache_area(void *addr, size_t len); extern void __clean_dcache_area_poc(void *addr, size_t len); diff --git a/arch/arm64/mm/cache.S b/arch/arm64/mm/cache.S index 7c54bcb..14eac9d 100644 --- a/arch/arm64/mm/cache.S +++ b/arch/arm64/mm/cache.S @@ -90,21 +90,12 @@ SYM_FUNC_END(__flush_cache_user_range) */ SYM_FUNC_START(invalidate_icache_range) alternative_if ARM64_HAS_CACHE_DIC - mov x0, xzr isb ret alternative_else_nop_endif - uaccess_ttbr0_enable x2, x3, x4 - - invalidate_icache_by_line x0, x1, x2, x3, 2f - mov x0, xzr -1: - uaccess_ttbr0_disable x1, x2 + invalidate_icache_by_line x0, x1, x2, x3 ret -2: - mov x0, #-EFAULT - b 1b SYM_FUNC_END(invalidate_icache_range) /* -- 2.7.4