diff options
| -rw-r--r-- | arch/arm/Kconfig | 15 | ||||
| -rw-r--r-- | arch/arm/include/asm/hardware/cache-l2x0.h | 1 | ||||
| -rw-r--r-- | arch/arm/mm/cache-l2x0.c | 6 |
3 files changed, 22 insertions, 0 deletions
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 26d45e5b636b..ba9fc213f344 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -1177,6 +1177,21 @@ config ARM_ERRATA_743622 visible impact on the overall performance or power consumption of the processor. +config ARM_ERRATA_753970 + bool "ARM errata: cache sync operation may be faulty" + depends on CACHE_PL310 + help + This option enables the workaround for the 753970 PL310 (r3p0) erratum. + + Under some condition the effect of cache sync operation on + the store buffer still remains when the operation completes. + This means that the store buffer is always asked to drain and + this prevents it from merging any further writes. The workaround + is to replace the normal offset of cache sync operation (0x730) + by another offset targeting an unmapped PL310 register 0x740. + This has the same effect as the cache sync operation: store buffer + drain and waiting for all buffers empty. + endmenu source "arch/arm/common/Kconfig" diff --git a/arch/arm/include/asm/hardware/cache-l2x0.h b/arch/arm/include/asm/hardware/cache-l2x0.h index 5aeec1e1735c..16bd48031583 100644 --- a/arch/arm/include/asm/hardware/cache-l2x0.h +++ b/arch/arm/include/asm/hardware/cache-l2x0.h @@ -36,6 +36,7 @@ #define L2X0_RAW_INTR_STAT 0x21C #define L2X0_INTR_CLEAR 0x220 #define L2X0_CACHE_SYNC 0x730 +#define L2X0_DUMMY_REG 0x740 #define L2X0_INV_LINE_PA 0x770 #define L2X0_INV_WAY 0x77C #define L2X0_CLEAN_LINE_PA 0x7B0 diff --git a/arch/arm/mm/cache-l2x0.c b/arch/arm/mm/cache-l2x0.c index 170c9bb95866..f2ce38e085d2 100644 --- a/arch/arm/mm/cache-l2x0.c +++ b/arch/arm/mm/cache-l2x0.c @@ -49,7 +49,13 @@ static inline void cache_wait(void __iomem *reg, unsigned long mask) static inline void cache_sync(void) { void __iomem *base = l2x0_base; + +#ifdef CONFIG_ARM_ERRATA_753970 + /* write to an unmmapped register */ + writel_relaxed(0, base + L2X0_DUMMY_REG); +#else writel_relaxed(0, base + L2X0_CACHE_SYNC); +#endif cache_wait(base + L2X0_CACHE_SYNC, 1); } |