From a672e99b129e286df2e2697a1b603d82321117f3 Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Tue, 14 Sep 2010 09:53:02 +0100 Subject: [PATCH] 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 Signed-off-by: Will Deacon Signed-off-by: Russell King --- arch/arm/Kconfig | 14 ++++++++++++++ arch/arm/mm/proc-v7.S | 9 +++++++++ 2 files changed, 23 insertions(+) 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 -- 2.20.1