ARM: 6201/1: RealView: Do not use outer_sync() on ARM11MPCore boards with L220

RealView boards with certain revisions of the L220 cache controller (ARM11*
processors only) may have issues (hardware deadlock) with the recent changes to
the mb() barrier implementation (DSB followed by an L2 cache sync). The patch
redefines the RealView ARM11MPCore mandatory barriers without the outer_sync()
call.

Cc: <stable@kernel.org>
Tested-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

2 files changed, 10 insertions, 0 deletions

diff --git a/arch/arm/mach-realview/Kconfig b/arch/arm/mach-realview/Kconfig
index ee5e392430e8..b4575ae9648e 100644
--- a/arch/arm/mach-realview/Kconfig
+++ b/arch/arm/mach-realview/Kconfig
@@ -18,6 +18,7 @@ config REALVIEW_EB_ARM11MP
         bool "Support ARM11MPCore tile"
         depends on MACH_REALVIEW_EB
         select CPU_V6
+        select ARCH_HAS_BARRIERS if SMP
         help
           Enable support for the ARM11MPCore tile on the Realview platform.
 
@@ -35,6 +36,7 @@ config MACH_REALVIEW_PB11MP
         select CPU_V6
         select ARM_GIC
         select HAVE_PATA_PLATFORM
+        select ARCH_HAS_BARRIERS if SMP
         help
           Include support for the ARM(R) RealView MPCore Platform Baseboard.
           PB11MPCore is a platform with an on-board ARM11MPCore and has
diff --git a/arch/arm/mach-realview/include/mach/barriers.h b/arch/arm/mach-realview/include/mach/barriers.h
new file mode 100644
index 000000000000..0c5d749d7b5f
--- /dev/null
+++ b/arch/arm/mach-realview/include/mach/barriers.h
@@ -0,0 +1,8 @@
+/*
+ * Barriers redefined for RealView ARM11MPCore platforms with L220 cache
+ * controller to work around hardware errata causing the outer_sync()
+ * operation to deadlock the system.
+ */
+#define mb()            dsb()
+#define rmb()           dmb()
+#define wmb()           mb()