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authorWill Deacon <will.deacon@arm.com>2011-09-15 11:45:15 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2011-09-17 12:47:17 +0100
commitf630c1bdfbf8fe423325beaf60027cfc7fd7c610 (patch)
tree9091179ae505fcb5aff937315c4f9c96602cba9a /arch/arm
parent279b1e0fd90ef63c7acb34a5ca573f065a6fefb4 (diff)
downloadlinux-stericsson-f630c1bdfbf8fe423325beaf60027cfc7fd7c610.tar.gz
ARM: 7091/1: errata: D-cache line maintenance operation by MVA may not succeed
This patch implements a 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. Cc: <stable@kernel.org> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Tested-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm')
-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 3269576dbfa8..3146ed3f6eca 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 79ed5e7f204a..7fcddb75c877 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 3b24bfa3b828..07c4bc8ea0a4 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