ARM: S5PV310: Set bit 22 in the PL310 (cache controller) AuxCtlr register
commit a50eb1c7 upstream. This patch is applied according to the commit 1a8e41cd (ARM: 6395/1: VExpress: Set bit 22 in the PL310 (cache controller) AuxCtlr register). Actually, S5PV310 has same cache controller(PL310). Following is from Catalin Marinas' commit. 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. Signed-off-by: Changhwan Youn <chaos.youn@samsung.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Kukjin Kim <kgene.kim@samsung.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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