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 kimoon.kim@samsung.com Signed-off-by: Akshay Saraswat akshay.s@samsung.com Reviewed-by: Simon Glass sjg@chromium.org Tested-by: Simon Glass sjg@chromium.org --- Changes since v3: - Added errata number in comment. - Moved changes to arm generic armv7.h
Changes since v2: - No change.
Changes since v1: - Added Reviewed-by & Tested-by. - Added space before */ on line # 40.
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 a13da23..a2040b7 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);