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: Rob Clark <rob@ti.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 12 insertions, 0 deletions

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 232f0c758252..e3956042892c 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -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"