From c01778001a4f5ad9c62d882776235f3f31922fdd Mon Sep 17 00:00:00 2001 From: Catalin Marinas Date: Mon, 13 Sep 2010 15:57:36 +0100 Subject: [PATCH] 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 Cc: Nicolas Pitre Signed-off-by: Catalin Marinas Signed-off-by: Russell King --- arch/arm/include/asm/cacheflush.h | 6 +++--- arch/arm/include/asm/tlbflush.h | 2 +- arch/arm/mm/copypage-v4mc.c | 2 +- arch/arm/mm/copypage-v6.c | 2 +- arch/arm/mm/copypage-xscale.c | 2 +- arch/arm/mm/dma-mapping.c | 6 ++++++ arch/arm/mm/fault-armv.c | 4 ++-- arch/arm/mm/flush.c | 3 ++- 8 files changed, 17 insertions(+), 10 deletions(-) diff --git a/arch/arm/include/asm/cacheflush.h b/arch/arm/include/asm/cacheflush.h index 4656a24058d2..d3730f0f4b50 100644 --- a/arch/arm/include/asm/cacheflush.h +++ b/arch/arm/include/asm/cacheflush.h @@ -137,10 +137,10 @@ #endif /* - * This flag is used to indicate that the page pointed to by a pte - * is dirty and requires cleaning before returning it to the user. + * This flag is used to indicate that the page pointed to by a pte is clean + * and does not require cleaning before returning it to the user. */ -#define PG_dcache_dirty PG_arch_1 +#define PG_dcache_clean PG_arch_1 /* * MM Cache Management diff --git a/arch/arm/include/asm/tlbflush.h b/arch/arm/include/asm/tlbflush.h index 33b546ae72d4..9ad329ad7458 100644 --- a/arch/arm/include/asm/tlbflush.h +++ b/arch/arm/include/asm/tlbflush.h @@ -560,7 +560,7 @@ extern void flush_tlb_kernel_range(unsigned long start, unsigned long end); #endif /* - * if PG_dcache_dirty is set for the page, we need to ensure that any + * If PG_dcache_clean is not set for the page, we need to ensure that any * cache entries for the kernels virtual memory range are written * back to the page. */ diff --git a/arch/arm/mm/copypage-v4mc.c b/arch/arm/mm/copypage-v4mc.c index 598c51ad5071..b8061519ce77 100644 --- a/arch/arm/mm/copypage-v4mc.c +++ b/arch/arm/mm/copypage-v4mc.c @@ -73,7 +73,7 @@ void v4_mc_copy_user_highpage(struct page *to, struct page *from, { void *kto = kmap_atomic(to, KM_USER1); - if (test_and_clear_bit(PG_dcache_dirty, &from->flags)) + if (!test_and_set_bit(PG_dcache_clean, &from->flags)) __flush_dcache_page(page_mapping(from), from); spin_lock(&minicache_lock); diff --git a/arch/arm/mm/copypage-v6.c b/arch/arm/mm/copypage-v6.c index f55fa1044f72..bdba6c65c901 100644 --- a/arch/arm/mm/copypage-v6.c +++ b/arch/arm/mm/copypage-v6.c @@ -79,7 +79,7 @@ static void v6_copy_user_highpage_aliasing(struct page *to, unsigned int offset = CACHE_COLOUR(vaddr); unsigned long kfrom, kto; - if (test_and_clear_bit(PG_dcache_dirty, &from->flags)) + if (!test_and_set_bit(PG_dcache_clean, &from->flags)) __flush_dcache_page(page_mapping(from), from); /* FIXME: not highmem safe */ diff --git a/arch/arm/mm/copypage-xscale.c b/arch/arm/mm/copypage-xscale.c index 9920c0ae2096..649bbcd325bf 100644 --- a/arch/arm/mm/copypage-xscale.c +++ b/arch/arm/mm/copypage-xscale.c @@ -95,7 +95,7 @@ void xscale_mc_copy_user_highpage(struct page *to, struct page *from, { void *kto = kmap_atomic(to, KM_USER1); - if (test_and_clear_bit(PG_dcache_dirty, &from->flags)) + if (!test_and_set_bit(PG_dcache_clean, &from->flags)) __flush_dcache_page(page_mapping(from), from); spin_lock(&minicache_lock); 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); diff --git a/arch/arm/mm/fault-armv.c b/arch/arm/mm/fault-armv.c index 9b906dec1ca1..58846cbd0e0b 100644 --- a/arch/arm/mm/fault-armv.c +++ b/arch/arm/mm/fault-armv.c @@ -141,7 +141,7 @@ make_coherent(struct address_space *mapping, struct vm_area_struct *vma, * a page table, or changing an existing PTE. Basically, there are two * things that we need to take care of: * - * 1. If PG_dcache_dirty is set for the page, we need to ensure + * 1. If PG_dcache_clean is not set for the page, we need to ensure * that any cache entries for the kernels virtual memory * range are written back to the page. * 2. If we have multiple shared mappings of the same space in @@ -169,7 +169,7 @@ void update_mmu_cache(struct vm_area_struct *vma, unsigned long addr, mapping = page_mapping(page); #ifndef CONFIG_SMP - if (test_and_clear_bit(PG_dcache_dirty, &page->flags)) + if (!test_and_set_bit(PG_dcache_clean, &page->flags)) __flush_dcache_page(mapping, page); #endif if (mapping) { diff --git a/arch/arm/mm/flush.c b/arch/arm/mm/flush.c index 87dd5ffdfa2d..b4efce9b7985 100644 --- a/arch/arm/mm/flush.c +++ b/arch/arm/mm/flush.c @@ -248,7 +248,7 @@ void flush_dcache_page(struct page *page) #ifndef CONFIG_SMP if (mapping && !mapping_mapped(mapping)) - set_bit(PG_dcache_dirty, &page->flags); + clear_bit(PG_dcache_clean, &page->flags); else #endif { @@ -257,6 +257,7 @@ void flush_dcache_page(struct page *page) __flush_dcache_aliases(mapping, page); else if (mapping) __flush_icache_all(); + set_bit(PG_dcache_clean, &page->flags); } } EXPORT_SYMBOL(flush_dcache_page); -- 2.39.2