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[ARM] 5489/1: ARM errata: Data written to the L2 cache can be overwritten with stale data 

This patch is a workaround for the 460075 Cortex-A8 (r2p0) erratum. It
configures the L2 cache auxiliary control register so that the Write
Allocate mode for the L2 cache is disabled.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This commit is contained in:
Catalin Marinas 2009-04-30 17:06:20 +01:00 committed by Russell King
parent 855c551f5b
commit 0516e4643c
2 changed files with 17 additions and 0 deletions
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12
arch/arm/Kconfig
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@ -778,6 +778,18 @@ config ARM_ERRATA_458693
in the ACTLR register. Note that setting specific bits in the ACTLR
register may not be available in non-secure mode.
config ARM_ERRATA_460075
bool "ARM errata: Data written to the L2 cache can be overwritten with stale data"
depends on CPU_V7
help
This option enables the workaround for the 460075 Cortex-A8 (r2p0)
erratum. Any asynchronous access to the L2 cache may encounter a
situation in which recent store transactions to the L2 cache are lost
and overwritten with stale memory contents from external memory. The
workaround disables the write-allocate mode for the L2 cache via the
ACTLR register. Note that setting specific bits in the ACTLR register
may not be available in non-secure mode.
endmenu
source "arch/arm/common/Kconfig"

5
arch/arm/mm/proc-v7.S
View File

@ -193,6 +193,11 @@ __v7_setup:
orr r10, r10, #(1 << 5) @ set L1NEON to 1
orr r10, r10, #(1 << 9) @ set PLDNOP to 1
mcr p15, 0, r10, c1, c0, 1 @ write aux control register
#endif
#ifdef CONFIG_ARM_ERRATA_460075
mrc p15, 1, r10, c9, c0, 2 @ read L2 cache aux ctrl register
orr r10, r10, #(1 << 22) @ set the Write Allocate disable bit
mcr p15, 1, r10, c9, c0, 2 @ write the L2 cache aux ctrl register
#endif
mov r10, #0
#ifdef HARVARD_CACHE