diff --git a/arch/arm/mach-omap2/Kconfig b/arch/arm/mach-omap2/Kconfig index 0517f0c1581a..a63d3fe2ca46 100644 --- a/arch/arm/mach-omap2/Kconfig +++ b/arch/arm/mach-omap2/Kconfig @@ -240,4 +240,12 @@ endmenu endif +config OMAP5_ERRATA_801819 + bool "Errata 801819: An eviction from L1 data cache might stall indefinitely" + depends on SOC_OMAP5 || SOC_DRA7XX + help + A livelock can occur in the L2 cache arbitration that might prevent + a snoop from completing. Under certain conditions this can cause the + system to deadlock. + endmenu diff --git a/arch/arm/mach-omap2/omap-secure.h b/arch/arm/mach-omap2/omap-secure.h index af2851fbcdf0..bae263fba640 100644 --- a/arch/arm/mach-omap2/omap-secure.h +++ b/arch/arm/mach-omap2/omap-secure.h @@ -46,6 +46,7 @@ #define OMAP5_DRA7_MON_SET_CNTFRQ_INDEX 0x109 #define OMAP5_MON_AMBA_IF_INDEX 0x108 +#define OMAP5_DRA7_MON_SET_ACR_INDEX 0x107 /* Secure PPA(Primary Protected Application) APIs */ #define OMAP4_PPA_L2_POR_INDEX 0x23 diff --git a/arch/arm/mach-omap2/omap-smp.c b/arch/arm/mach-omap2/omap-smp.c index c625cc10d9f9..8cd1de914ee4 100644 --- a/arch/arm/mach-omap2/omap-smp.c +++ b/arch/arm/mach-omap2/omap-smp.c @@ -50,6 +50,39 @@ void __iomem *omap4_get_scu_base(void) return scu_base; } +#ifdef CONFIG_OMAP5_ERRATA_801819 +void omap5_erratum_workaround_801819(void) +{ + u32 acr, revidr; + u32 acr_mask; + + /* REVIDR[3] indicates erratum fix available on silicon */ + asm volatile ("mrc p15, 0, %0, c0, c0, 6" : "=r" (revidr)); + if (revidr & (0x1 << 3)) + return; + + asm volatile ("mrc p15, 0, %0, c1, c0, 1" : "=r" (acr)); + /* + * BIT(27) - Disables streaming. All write-allocate lines allocate in + * the L1 or L2 cache. + * BIT(25) - Disables streaming. All write-allocate lines allocate in + * the L1 cache. + */ + acr_mask = (0x3 << 25) | (0x3 << 27); + /* do we already have it done.. if yes, skip expensive smc */ + if ((acr & acr_mask) == acr_mask) + return; + + acr |= acr_mask; + omap_smc1(OMAP5_DRA7_MON_SET_ACR_INDEX, acr); + + pr_debug("%s: ARM erratum workaround 801819 applied on CPU%d\n", + __func__, smp_processor_id()); +} +#else +static inline void omap5_erratum_workaround_801819(void) { } +#endif + static void omap4_secondary_init(unsigned int cpu) { /* @@ -64,12 +97,15 @@ static void omap4_secondary_init(unsigned int cpu) omap_secure_dispatcher(OMAP4_PPA_CPU_ACTRL_SMP_INDEX, 4, 0, 0, 0, 0, 0); - /* - * Configure the CNTFRQ register for the secondary cpu's which - * indicates the frequency of the cpu local timers. - */ - if (soc_is_omap54xx() || soc_is_dra7xx()) + if (soc_is_omap54xx() || soc_is_dra7xx()) { + /* + * Configure the CNTFRQ register for the secondary cpu's which + * indicates the frequency of the cpu local timers. + */ set_cntfreq(); + /* Configure ACR to disable streaming WA for 801819 */ + omap5_erratum_workaround_801819(); + } /* * Synchronise with the boot thread. @@ -218,6 +254,8 @@ static void __init omap4_smp_prepare_cpus(unsigned int max_cpus) if (cpu_is_omap446x()) startup_addr = omap4460_secondary_startup; + if (soc_is_dra74x() || soc_is_omap54xx()) + omap5_erratum_workaround_801819(); /* * Write the address of secondary startup routine into the