From 0c08baf05317c723214ba6e0ba89e4a4d9e0d3f1 Mon Sep 17 00:00:00 2001 From: Akshay Saraswat Date: Fri, 20 Feb 2015 13:27:13 +0530 Subject: [PATCH] Exynos542x: Add workaround for ARM errata 798870 This patch adds workaround for ARM errata 798870 which says "If back-to-back speculative cache line fills (fill A and fill B) are issued from the L1 data cache of a CPU to the L2 cache, the second request (fill B) is then cancelled, and the second request would have detected a hazard against a recent write or eviction (write B) to the same cache line as fill B then the L2 logic might deadlock." Signed-off-by: Kimoon Kim Signed-off-by: Akshay Saraswat Reviewed-by: Simon Glass Tested-by: Simon Glass Signed-off-by: Minkyu Kang --- arch/arm/include/asm/armv7.h | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/arch/arm/include/asm/armv7.h b/arch/arm/include/asm/armv7.h index a13da23cf1..a2040b776d 100644 --- a/arch/arm/include/asm/armv7.h +++ b/arch/arm/include/asm/armv7.h @@ -69,6 +69,22 @@ #define CP15DSB asm volatile ("mcr p15, 0, %0, c7, c10, 4" : : "r" (0)) #define CP15DMB asm volatile ("mcr p15, 0, %0, c7, c10, 5" : : "r" (0)) +/* + * Workaround for ARM errata # 798870 + * Set L2ACTLR[7] to reissue any memory transaction in the L2 that has been + * stalled for 1024 cycles to verify that its hazard condition still exists. + */ +static inline void v7_enable_l2_hazard_detect(void) +{ + uint32_t val; + + /* L2ACTLR[7]: Enable hazard detect timeout */ + asm volatile ("mrc p15, 1, %0, c15, c0, 0\n\t" : "=r"(val)); + val |= (1 << 7); + asm volatile ("mcr p15, 1, %0, c15, c0, 0\n\t" : : "r"(val)); +} + +void v7_en_l2_hazard_detect(void); void v7_outer_cache_enable(void); void v7_outer_cache_disable(void); void v7_outer_cache_flush_all(void); -- 2.39.5