From bae0ca2bc550d1ec6a118fb8f2696f18c4da3d8e Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Fri, 7 Feb 2014 19:12:20 +0100 Subject: ARM: 7953/1: mm: ensure TLB invalidation is complete before enabling MMU During __v{6,7}_setup, we invalidate the TLBs since we are about to enable the MMU on return to head.S. Unfortunately, without a subsequent dsb instruction, the invalidation is not guaranteed to have completed by the time we write to the sctlr, potentially exposing us to junk/stale translations cached in the TLB. This patch reworks the init functions so that the dsb used to ensure completion of cache/predictor maintenance is also used to ensure completion of the TLB invalidation. Cc: Reported-by: Albin Tonnerre Signed-off-by: Will Deacon Signed-off-by: Russell King --- arch/arm/mm/proc-v6.S | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'arch/arm/mm/proc-v6.S') diff --git a/arch/arm/mm/proc-v6.S b/arch/arm/mm/proc-v6.S index 45dc29f85d56..32b3558321c4 100644 --- a/arch/arm/mm/proc-v6.S +++ b/arch/arm/mm/proc-v6.S @@ -208,7 +208,6 @@ __v6_setup: mcr p15, 0, r0, c7, c14, 0 @ clean+invalidate D cache mcr p15, 0, r0, c7, c5, 0 @ invalidate I cache mcr p15, 0, r0, c7, c15, 0 @ clean+invalidate cache - mcr p15, 0, r0, c7, c10, 4 @ drain write buffer #ifdef CONFIG_MMU mcr p15, 0, r0, c8, c7, 0 @ invalidate I + D TLBs mcr p15, 0, r0, c2, c0, 2 @ TTB control register @@ -218,6 +217,8 @@ __v6_setup: ALT_UP(orr r8, r8, #TTB_FLAGS_UP) mcr p15, 0, r8, c2, c0, 1 @ load TTB1 #endif /* CONFIG_MMU */ + mcr p15, 0, r0, c7, c10, 4 @ drain write buffer and + @ complete invalidations adr r5, v6_crval ldmia r5, {r5, r6} ARM_BE8(orr r6, r6, #1 << 25) @ big-endian page tables -- cgit v1.2.3