Merge tag 'omap-for-v4.7/fixes-v2' of git://git.kernel.org/pub/scm/linux/kernel/git...

Two fixes for omaps for v4.7 merge window, one to enable
ARM errata for am437x, and the other to add ARM errtum
workaround for dra7.

AFAIK these both can wait for v4.7, we can then request them
for stable kernels as needed.

* tag 'omap-for-v4.7/fixes-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap:
  ARM: OMAP2+: AM43XX: Enable fixes for Cortex-A9 errata
  ARM: OMAP5 / DRA7: Introduce workaround for 801819

Signed-off-by: Olof Johansson <olof@lixom.net>

diff --git a/arch/arm/mach-omap2/Kconfig b/arch/arm/mach-omap2/Kconfig
index 0517f0c..415a0bd 100644 (file)
--- a/arch/arm/mach-omap2/Kconfig
+++ b/arch/arm/mach-omap2/Kconfig
@@ -67,6 +67,8 @@ config SOC_AM43XX
        select HAVE_ARM_SCU
        select GENERIC_CLOCKEVENTS_BROADCAST
        select HAVE_ARM_TWD
+       select ARM_ERRATA_754322
+       select ARM_ERRATA_775420
 
 config SOC_DRA7XX
        bool "TI DRA7XX"
@@ -240,4 +242,12 @@ 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 af2851f..bae263f 100644 (file)
--- 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 c625cc1..8cd1de9 100644 (file)
--- 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