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-v7.S | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/arm/mm/proc-v7.S') diff --git a/arch/arm/mm/proc-v7.S b/arch/arm/mm/proc-v7.S index bd1781979a39..74f6033e76dd 100644 --- a/arch/arm/mm/proc-v7.S +++ b/arch/arm/mm/proc-v7.S @@ -351,7 +351,6 @@ __v7_setup: 4: mov r10, #0 mcr p15, 0, r10, c7, c5, 0 @ I+BTB cache invalidate - dsb #ifdef CONFIG_MMU mcr p15, 0, r10, c8, c7, 0 @ invalidate I + D TLBs v7_ttb_setup r10, r4, r8, r5 @ TTBCR, TTBRx setup @@ -360,6 +359,7 @@ __v7_setup: mcr p15, 0, r5, c10, c2, 0 @ write PRRR mcr p15, 0, r6, c10, c2, 1 @ write NMRR #endif + dsb @ Complete invalidations #ifndef CONFIG_ARM_THUMBEE mrc p15, 0, r0, c0, c1, 0 @ read ID_PFR0 for ThumbEE and r0, r0, #(0xf << 12) @ ThumbEE enabled field -- cgit