From: Will Deacon Date: Fri, 7 Feb 2014 18:12:20 +0000 (+0100) Subject: ARM: 7953/1: mm: ensure TLB invalidation is complete before enabling MMU X-Git-Tag: firefly_0821_release~176^2~4317^2~9 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=bae0ca2bc550d1ec6a118fb8f2696f18c4da3d8e;p=firefly-linux-kernel-4.4.55.git 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 --- 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 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