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authorCatalin Marinas <catalin.marinas@arm.com>2010-09-13 15:57:36 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2010-09-19 12:17:43 +0100
commitc01778001a4f5ad9c62d882776235f3f31922fdd (patch)
treea425979b236dd5c7757e9a1f0c66d3819ad99021 /arch/arm/mm/dma-mapping.c
parent0fc73099dd25df2c5181b7bad57d1faa5cd12d3c (diff)
ARM: 6379/1: Assume new page cache pages have dirty D-cache
There are places in Linux where writes to newly allocated page cache pages happen without a subsequent call to flush_dcache_page() (several PIO drivers including USB HCD). This patch changes the meaning of PG_arch_1 to be PG_dcache_clean and always flush the D-cache for a newly mapped page in update_mmu_cache(). The patch also sets the PG_arch_1 bit in the DMA cache maintenance function to avoid additional cache flushing in update_mmu_cache(). Tested-by: Rabin Vincent <rabin.vincent@stericsson.com> Cc: Nicolas Pitre <nicolas.pitre@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/mm/dma-mapping.c')
-rw-r--r--arch/arm/mm/dma-mapping.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index 4bc43e535d3..e4dd0646e85 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -523,6 +523,12 @@ void ___dma_page_dev_to_cpu(struct page *page, unsigned long off,
outer_inv_range(paddr, paddr + size);
dma_cache_maint_page(page, off, size, dir, dmac_unmap_area);
+
+ /*
+ * Mark the D-cache clean for this page to avoid extra flushing.
+ */
+ if (dir != DMA_TO_DEVICE && off == 0 && size >= PAGE_SIZE)
+ set_bit(PG_dcache_clean, &page->flags);
}
EXPORT_SYMBOL(___dma_page_dev_to_cpu);