[ARM] 2943/1: Clear the exclusive monitor in v6_early_abort

Patch from Catalin Marinas

Data abort caused by ldrex/strex can leave the exclusive monitor in an
unpredictable state. It is recommended that a clrex/strex is performed to
clear this state.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 5 insertions, 0 deletions

diff --git a/arch/arm/mm/abort-ev6.S b/arch/arm/mm/abort-ev6.S
index 8f76f3df7b4c..dbd346033122 100644
--- a/arch/arm/mm/abort-ev6.S
+++ b/arch/arm/mm/abort-ev6.S
@@ -20,6 +20,11 @@
  */
         .align  5
 ENTRY(v6_early_abort)
+#ifdef CONFIG_CPU_MPCORE
+        clrex
+#else
+        strex   r0, r1, [sp]                    @ Clear the exclusive monitor
+#endif
         mrc     p15, 0, r1, c5, c0, 0           @ get FSR
         mrc     p15, 0, r0, c6, c0, 0           @ get FAR
 /*