ARM: 7541/1: Add ARM ERRATA 775420 workaround

commit 7253b85cc62d6ff84143d96fe6cd54f73736f4d7 upstream.

arm: Add ARM ERRATA 775420 workaround

Workaround for the 775420 Cortex-A9 (r2p2, r2p6,r2p8,r2p10,r3p0) erratum.
In case a date cache maintenance operation aborts with MMU exception, it
might cause the processor to deadlock. This workaround puts DSB before
executing ISB if an abort may occur on cache maintenance.

Based on work by Kouei Abe and feedback from Catalin Marinas.

Signed-off-by: Kouei Abe <kouei.abe.cp@rms.renesas.com>
[ horms@verge.net.au: Changed to implementation
  suggested by catalin.marinas@arm.com ]
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 352322a676510184602840c7cdf4d49af8c41fa4..e14ae1141429b9ea596e58a1ce33d5a759e7ff92 100644 (file)
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -1405,6 +1405,16 @@ config PL310_ERRATA_769419
          on systems with an outer cache, the store buffer is drained
          explicitly.
 
+config ARM_ERRATA_775420
+       bool "ARM errata: A data cache maintenance operation which aborts, might lead to deadlock"
+       depends on CPU_V7
+       help
+        This option enables the workaround for the 775420 Cortex-A9 (r2p2,
+        r2p6,r2p8,r2p10,r3p0) erratum. In case a date cache maintenance
+        operation aborts with MMU exception, it might cause the processor
+        to deadlock. This workaround puts DSB before executing ISB if
+        an abort may occur on cache maintenance.
+
 endmenu
 
 source "arch/arm/common/Kconfig"

diff --git a/arch/arm/mm/cache-v7.S b/arch/arm/mm/cache-v7.S
index a655d3da386d6c3620a07bc25176163c21a07e15..82ab2c5b4ac4eec3ae6ed2f4c267645fa7c286ff 100644 (file)
--- a/arch/arm/mm/cache-v7.S
+++ b/arch/arm/mm/cache-v7.S
@@ -211,6 +211,9 @@ ENTRY(v7_coherent_user_range)
  * isn't mapped, just try the next page.
  */
 9001:
+#ifdef CONFIG_ARM_ERRATA_775420
+       dsb
+#endif
        mov     r12, r12, lsr #12
        mov     r12, r12, lsl #12
        add     r12, r12, #4096