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| author | Catalin Marinas <catalin.marinas@arm.com> | 2010-09-13 16:57:36 +0200 |
|---|---|---|
| committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2010-09-19 13:17:43 +0200 |
| commit | c01778001a4f5ad9c62d882776235f3f31922fdd (patch) | |
| tree | a425979b236dd5c7757e9a1f0c66d3819ad99021 /arch/arm/mm/dma-mapping.c | |
| parent | ARM: 6378/1: Allow lazy cache flushing via PG_arch_1 for highmem pages (diff) | |
| download | linux-c01778001a4f5ad9c62d882776235f3f31922fdd.tar.xz linux-c01778001a4f5ad9c62d882776235f3f31922fdd.zip | |
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.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c index 4bc43e535d3b..e4dd0646e859 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); |