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ARM: 6395/1: VExpress: Set bit 22 in the PL310 (cache controller) AuxCtlr register

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Clearing bit 22 in the PL310 Auxiliary Control register (shared
attribute override enable) has the side effect of transforming Normal
Shared Non-cacheable reads into Cacheable no-allocate reads.

Coherent DMA buffers in Linux always have a Cacheable alias via the
kernel linear mapping and the processor can speculatively load cache
lines into the PL310 controller. With bit 22 cleared, Non-cacheable
reads would unexpectedly hit such cache lines leading to buffer
corruption.

Cc: Nicolas Pitre <nicolas.pitre@linaro.org>
Cc: <stable@kernel.org>
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 2010-09-16 17:57:17 +01:00 • committed by Russell King
commit 1a8e41cd67
1 changed files with 1 additions and 1 deletions
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2
arch/arm/mach-vexpress/ct-ca9x4.c
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@ -227,7 +227,7 @@ static void ct_ca9x4_init(void)
int i;
#ifdef CONFIG_CACHE_L2X0
l2x0_init(MMIO_P2V(CT_CA9X4_L2CC), 0x00000000, 0xfe0fffff);
l2x0_init(MMIO_P2V(CT_CA9X4_L2CC), 0x00400000, 0xfe0fffff);
#endif
clkdev_add_table(lookups, ARRAY_SIZE(lookups));