3 files changed, 52 insertions, 5 deletions

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