From 7f0b1bf04511348995d6fce38c87c98a3b5cb781 Mon Sep 17 00:00:00 2001 From: Catalin Marinas Date: Mon, 9 Jun 2014 11:55:03 +0100 Subject: arm64: Fix barriers used for page table modifications The architecture specification states that both DSB and ISB are required between page table modifications and subsequent memory accesses using the corresponding virtual address. When TLB invalidation takes place, the tlb_flush_* functions already have the necessary barriers. However, there are other functions like create_mapping() for which this is not the case. The patch adds the DSB+ISB instructions in the set_pte() function for valid kernel mappings. The invalid pte case is handled by tlb_flush_* and the user mappings in general have a corresponding update_mmu_cache() call containing a DSB. Even when update_mmu_cache() isn't called, the kernel can still cope with an unlikely spurious page fault by re-executing the instruction. In addition, the set_pmd, set_pud() functions gain an ISB for architecture compliance when block mappings are created. Signed-off-by: Catalin Marinas Reported-by: Leif Lindholm Acked-by: Steve Capper Cc: Will Deacon Cc: --- arch/arm64/include/asm/cacheflush.h | 11 +---------- 1 file changed, 1 insertion(+), 10 deletions(-) (limited to 'arch/arm64/include/asm/cacheflush.h') diff --git a/arch/arm64/include/asm/cacheflush.h b/arch/arm64/include/asm/cacheflush.h index a5176cf32da..f2defe1c380 100644 --- a/arch/arm64/include/asm/cacheflush.h +++ b/arch/arm64/include/asm/cacheflush.h @@ -138,19 +138,10 @@ static inline void __flush_icache_all(void) #define flush_icache_page(vma,page) do { } while (0) /* - * flush_cache_vmap() is used when creating mappings (eg, via vmap, - * vmalloc, ioremap etc) in kernel space for pages. On non-VIPT - * caches, since the direct-mappings of these pages may contain cached - * data, we need to do a full cache flush to ensure that writebacks - * don't corrupt data placed into these pages via the new mappings. + * Not required on AArch64 (PIPT or VIPT non-aliasing D-cache). */ static inline void flush_cache_vmap(unsigned long start, unsigned long end) { - /* - * set_pte_at() called from vmap_pte_range() does not - * have a DSB after cleaning the cache line. - */ - dsb(ish); } static inline void flush_cache_vunmap(unsigned long start, unsigned long end) -- cgit v1.2.3-70-g09d2