[PATCH 1/2] ARM: implement recommended WAR for errata 709718

[Lucas Stach]

ARM Cortex A8 errata 709718:
"Load and store operations to shared device memory
regions may not complete in program order"

We implement the recommended workaround in the bootloader
as it must be applied before enabling the MMU for the
first time.

Signed-off-by: Lucas Stach <l.stach at pengutronix.de>
---
 arch/arm/include/asm/errata.h | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/arch/arm/include/asm/errata.h b/arch/arm/include/asm/errata.h
index e2ffd87360c0..9525823e4ca8 100644
--- a/arch/arm/include/asm/errata.h
+++ b/arch/arm/include/asm/errata.h
@@ -12,6 +12,18 @@
  * GNU General Public License for more details.
  */
 
+static inline void enable_arm_errata_709718_war(void)
+{
+	__asm__ __volatile__ (
+		"mrc	p15, 0, r0, c10, c2, 0\n"
+		"bic	r0, #3 << 16\n"
+		"mcr	p15, 0, r0, c10, c2, 0\n"
+		"mrc	p15, 0, r0, c1, c0, 0\n"
+		"orr	r0, r0, #1 << 28\n"
+		"mcr	p15, 0, r0, c1, c0, 0\n"
+	);
+}
+
 static inline void enable_arm_errata_716044_war(void)
 {
 	__asm__ __volatile__ (
-- 
2.1.1