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ARM: 7953/1: mm: ensure TLB invalidation is complete before enabling MMU

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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: <stable@vger.kernel.org>
Reported-by: Albin Tonnerre <Albin.Tonnerre@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This commit is contained in:
Will Deacon 2014-02-07 19:12:20 +01:00 • committed by Russell King
parent ca47440847
commit bae0ca2bc5
2 changed files with 3 additions and 2 deletions
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3
arch/arm/mm/proc-v6.S
View file

@ -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

2
arch/arm/mm/proc-v7.S
View file

@ -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