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authorWill Deacon <will.deacon@arm.com>2010-09-14 09:53:02 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2010-09-17 10:16:52 +0100
commita672e99b129e286df2e2697a1b603d82321117f3 (patch)
tree3307cdb68df62a67d78309ecdf6c35cab7321892 /arch
parent9f05027c7cb3cfe56a31892bd83391138d41a667 (diff)
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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>
Diffstat (limited to 'arch')
-rw-r--r--arch/arm/Kconfig14
-rw-r--r--arch/arm/mm/proc-v7.S9
2 files changed, 23 insertions, 0 deletions
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index ab14c0a5d21e..0f89335b84c2 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -1063,6 +1063,20 @@ config ARM_ERRATA_742230
instruction to behave as a DSB, ensuring the correct behaviour of
the two writes.
+config ARM_ERRATA_742231
+ bool "ARM errata: Incorrect hazard handling in the SCU may lead to data corruption"
+ depends on CPU_V7 && SMP
+ help
+ This option enables the workaround for the 742231 Cortex-A9
+ (r2p0..r2p2) erratum. Under certain conditions, specific to the
+ Cortex-A9 MPCore micro-architecture, two CPUs working in SMP mode,
+ accessing some data located in the same cache line, may get corrupted
+ data due to bad handling of the address hazard when the line gets
+ replaced from one of the CPUs at the same time as another CPU is
+ accessing it. This workaround sets specific bits in the diagnostic
+ register of the Cortex-A9 which reduces the linefill issuing
+ capabilities of the processor.
+
config PL310_ERRATA_588369
bool "Clean & Invalidate maintenance operations do not invalidate clean lines"
depends on CACHE_L2X0 && ARCH_OMAP4
diff --git a/arch/arm/mm/proc-v7.S b/arch/arm/mm/proc-v7.S
index 945f36341fa6..080129263eef 100644
--- a/arch/arm/mm/proc-v7.S
+++ b/arch/arm/mm/proc-v7.S
@@ -243,6 +243,15 @@ __v7_setup:
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