ARM: 6389/1: errata: incorrect hazard handling in the SCU may lead to data corruption
On the r2p0, r2p1 and r2p2 versions of the Cortex-A9, data corruption
can occur if a shared cache line is replaced on one CPU as another CPU
is accessing it.
This workaround sets two bits in the diagnostic register of the Cortex-A9,
reducing the linefill issuing capabilities of the processor and
avoiding the erroneous behaviour.
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/mm/proc-v7.S b/arch/arm/mm/proc-v7.S
index 945f363..0801292 100644
--- a/arch/arm/mm/proc-v7.S
+++ b/arch/arm/mm/proc-v7.S
@@ -243,6 +243,15 @@
orrle r10, r10, #1 << 4 @ set bit #4
mcrle p15, 0, r10, c15, c0, 1 @ write diagnostic register
#endif
+#ifdef CONFIG_ARM_ERRATA_742231
+ teq r6, #0x20 @ present in r2p0
+ teqne r6, #0x21 @ present in r2p1
+ teqne r6, #0x22 @ present in r2p2
+ mrceq p15, 0, r10, c15, c0, 1 @ read diagnostic register
+ orreq r10, r10, #1 << 12 @ set bit #12
+ orreq r10, r10, #1 << 22 @ set bit #22
+ mcreq p15, 0, r10, c15, c0, 1 @ write diagnostic register
+#endif
3: mov r10, #0
#ifdef HARVARD_CACHE