Commit cdf357f1 authored by Will Deacon's avatar Will Deacon Committed by Russell King
Browse files

ARM: 6299/1: errata: TLBIASIDIS and TLBIMVAIS operations can broadcast a faulty ASID 



On versions of the Cortex-A9 prior to r2p0, performing TLB invalidations by
ASID match can result in the incorrect ASID being broadcast to other CPUs.
As a consequence of this, the targetted TLB entries are not invalidated
across the system.

This workaround changes the TLB flushing routines to invalidate entries
regardless of the ASID.

Cc: <stable@kernel.org>
Tested-by: default avatarRob Clark <rob@ti.com>
Acked-by: default avatarCatalin Marinas <catalin.marinas@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 988257cf

arch/arm/Kconfig

+12 −0
Original line number Diff line number Diff line
@@ -1040,6 +1040,18 @@ config PL310_ERRATA_588369 
	   is not correctly implemented in PL310 as clean lines are not

	   invalidated as a result of these operations. Note that this errata

	   uses Texas Instrument's secure monitor api.



config ARM_ERRATA_720789

	bool "ARM errata: TLBIASIDIS and TLBIMVAIS operations can broadcast a faulty ASID"

	depends on CPU_V7 && SMP

	help

	  This option enables the workaround for the 720789 Cortex-A9 (prior to

	  r2p0) erratum. A faulty ASID can be sent to the other CPUs for the

	  broadcasted CP15 TLB maintenance operations TLBIASIDIS and TLBIMVAIS.

	  As a consequence of this erratum, some TLB entries which should be

	  invalidated are not, resulting in an incoherency in the system page

	  tables. The workaround changes the TLB flushing routines to invalidate

	  entries regardless of the ASID.

endmenu



source "arch/arm/common/Kconfig"

arch/arm/include/asm/tlbflush.h

+8 −0
Original line number Diff line number Diff line
@@ -378,7 +378,11 @@ static inline void local_flush_tlb_mm(struct mm_struct *mm) 
	if (tlb_flag(TLB_V6_I_ASID))

		asm("mcr p15, 0, %0, c8, c5, 2" : : "r" (asid) : "cc");

	if (tlb_flag(TLB_V7_UIS_ASID))

#ifdef CONFIG_ARM_ERRATA_720789

		asm("mcr p15, 0, %0, c8, c3, 0" : : "r" (zero) : "cc");

#else

		asm("mcr p15, 0, %0, c8, c3, 2" : : "r" (asid) : "cc");

#endif



	if (tlb_flag(TLB_BTB)) {

		/* flush the branch target cache */
@@ -424,7 +428,11 @@ local_flush_tlb_page(struct vm_area_struct *vma, unsigned long uaddr) 
	if (tlb_flag(TLB_V6_I_PAGE))

		asm("mcr p15, 0, %0, c8, c5, 1" : : "r" (uaddr) : "cc");

	if (tlb_flag(TLB_V7_UIS_PAGE))

#ifdef CONFIG_ARM_ERRATA_720789

		asm("mcr p15, 0, %0, c8, c3, 3" : : "r" (uaddr & PAGE_MASK) : "cc");

#else

		asm("mcr p15, 0, %0, c8, c3, 1" : : "r" (uaddr) : "cc");

#endif



	if (tlb_flag(TLB_BTB)) {

		/* flush the branch target cache */

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