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Commit bae0ca2b authored by Will Deacon's avatar Will Deacon Committed by Russell King
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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: <stable@vger.kernel.org>
Reported-by: default avatarAlbin Tonnerre <Albin.Tonnerre@arm.com>
Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent ca474408

arch/arm/mm/proc-v6.S

+2 −1
Original line number Diff line number Diff line
@@ -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

arch/arm/mm/proc-v7.S

+1 −1
Original line number Diff line number Diff line
@@ -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