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ARM: 7091/1: errata: D-cache line maintenance operation by MVA may not succeed

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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>
This commit is contained in:
Will Deacon 2011-09-15 11:45:15 +01:00 committed by Russell King
parent 279b1e0fd9
commit f630c1bdfb
3 changed files with 44 additions and 0 deletions
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14
arch/arm/Kconfig
View File

@ -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"

10
arch/arm/kernel/smp_scu.c
View File

@ -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)

20
arch/arm/mm/cache-v7.S
View File

@ -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