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-rw-r--r--arch/arm/Kconfig14
-rw-r--r--arch/arm/kernel/smp_scu.c10
-rw-r--r--arch/arm/mm/cache-v7.S20
3 files changed, 44 insertions, 0 deletions
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 3269576dbfa..3146ed3f6ec 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -1283,6 +1283,20 @@ config ARM_ERRATA_364296
processor into full low interrupt latency mode. ARM11MPCore
is not affected.
+config ARM_ERRATA_764369
+ bool "ARM errata: Data cache line maintenance operation by MVA may not succeed"
+ depends on CPU_V7 && SMP
+ help
+ This option enables the workaround for erratum 764369
+ affecting Cortex-A9 MPCore with two or more processors (all
+ current revisions). Under certain timing circumstances, a data
+ cache line maintenance operation by MVA targeting an Inner
+ Shareable memory region may fail to proceed up to either the
+ Point of Coherency or to the Point of Unification of the
+ system. This workaround adds a DSB instruction before the
+ relevant cache maintenance functions and sets a specific bit
+ in the diagnostic control register of the SCU.
+
endmenu
source "arch/arm/common/Kconfig"
diff --git a/arch/arm/kernel/smp_scu.c b/arch/arm/kernel/smp_scu.c
index 79ed5e7f204..7fcddb75c87 100644
--- a/arch/arm/kernel/smp_scu.c
+++ b/arch/arm/kernel/smp_scu.c
@@ -13,6 +13,7 @@
#include <asm/smp_scu.h>
#include <asm/cacheflush.h>
+#include <asm/cputype.h>
#define SCU_CTRL 0x00
#define SCU_CONFIG 0x04
@@ -37,6 +38,15 @@ void __init scu_enable(void __iomem *scu_base)
{
u32 scu_ctrl;
+#ifdef CONFIG_ARM_ERRATA_764369
+ /* Cortex-A9 only */
+ if ((read_cpuid(CPUID_ID) & 0xff0ffff0) == 0x410fc090) {
+ scu_ctrl = __raw_readl(scu_base + 0x30);
+ if (!(scu_ctrl & 1))
+ __raw_writel(scu_ctrl | 0x1, scu_base + 0x30);
+ }
+#endif
+
scu_ctrl = __raw_readl(scu_base + SCU_CTRL);
/* already enabled? */
if (scu_ctrl & 1)
diff --git a/arch/arm/mm/cache-v7.S b/arch/arm/mm/cache-v7.S
index 3b24bfa3b82..07c4bc8ea0a 100644
--- a/arch/arm/mm/cache-v7.S
+++ b/arch/arm/mm/cache-v7.S
@@ -174,6 +174,10 @@ ENTRY(v7_coherent_user_range)
dcache_line_size r2, r3
sub r3, r2, #1
bic r12, r0, r3
+#ifdef CONFIG_ARM_ERRATA_764369
+ ALT_SMP(W(dsb))
+ ALT_UP(W(nop))
+#endif
1:
USER( mcr p15, 0, r12, c7, c11, 1 ) @ clean D line to the point of unification
add r12, r12, r2
@@ -223,6 +227,10 @@ ENTRY(v7_flush_kern_dcache_area)
add r1, r0, r1
sub r3, r2, #1
bic r0, r0, r3
+#ifdef CONFIG_ARM_ERRATA_764369
+ ALT_SMP(W(dsb))
+ ALT_UP(W(nop))
+#endif
1:
mcr p15, 0, r0, c7, c14, 1 @ clean & invalidate D line / unified line
add r0, r0, r2
@@ -247,6 +255,10 @@ v7_dma_inv_range:
sub r3, r2, #1
tst r0, r3
bic r0, r0, r3
+#ifdef CONFIG_ARM_ERRATA_764369
+ ALT_SMP(W(dsb))
+ ALT_UP(W(nop))
+#endif
mcrne p15, 0, r0, c7, c14, 1 @ clean & invalidate D / U line
tst r1, r3
@@ -270,6 +282,10 @@ v7_dma_clean_range:
dcache_line_size r2, r3
sub r3, r2, #1
bic r0, r0, r3
+#ifdef CONFIG_ARM_ERRATA_764369
+ ALT_SMP(W(dsb))
+ ALT_UP(W(nop))
+#endif
1:
mcr p15, 0, r0, c7, c10, 1 @ clean D / U line
add r0, r0, r2
@@ -288,6 +304,10 @@ ENTRY(v7_dma_flush_range)
dcache_line_size r2, r3
sub r3, r2, #1
bic r0, r0, r3
+#ifdef CONFIG_ARM_ERRATA_764369
+ ALT_SMP(W(dsb))
+ ALT_UP(W(nop))
+#endif
1:
mcr p15, 0, r0, c7, c14, 1 @ clean & invalidate D / U line
add r0, r0, r2