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-rw-r--r--arch/arm/Kconfig11
-rw-r--r--arch/arm/mm/proc-v7.S6
2 files changed, 17 insertions, 0 deletions
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 166efa2a19c..ec0f6589af0 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -1202,6 +1202,17 @@ config ARM_ERRATA_753970
This has the same effect as the cache sync operation: store buffer
drain and waiting for all buffers empty.
+config ARM_ERRATA_754322
+ bool "ARM errata: possible faulty MMU translations following an ASID switch"
+ depends on CPU_V7
+ help
+ This option enables the workaround for the 754322 Cortex-A9 (r2p*,
+ r3p*) erratum. A speculative memory access may cause a page table walk
+ which starts prior to an ASID switch but completes afterwards. This
+ can populate the micro-TLB with a stale entry which may be hit with
+ the new ASID. This workaround places two dsb instructions in the mm
+ switching code so that no page table walks can cross the ASID switch.
+
endmenu
source "arch/arm/common/Kconfig"
diff --git a/arch/arm/mm/proc-v7.S b/arch/arm/mm/proc-v7.S
index 8e335623913..f7498f1a2e8 100644
--- a/arch/arm/mm/proc-v7.S
+++ b/arch/arm/mm/proc-v7.S
@@ -108,10 +108,16 @@ ENTRY(cpu_v7_switch_mm)
#ifdef CONFIG_ARM_ERRATA_430973
mcr p15, 0, r2, c7, c5, 6 @ flush BTAC/BTB
#endif
+#ifdef CONFIG_ARM_ERRATA_754322
+ dsb
+#endif
mcr p15, 0, r2, c13, c0, 1 @ set reserved context ID
isb
1: mcr p15, 0, r0, c2, c0, 0 @ set TTB 0
isb
+#ifdef CONFIG_ARM_ERRATA_754322
+ dsb
+#endif
mcr p15, 0, r1, c13, c0, 1 @ set context ID
isb
#endif