From c01778001a4f5ad9c62d882776235f3f31922fdd Mon Sep 17 00:00:00 2001 From: Catalin Marinas Date: Mon, 13 Sep 2010 15:57:36 +0100 Subject: 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/mm/fault-armv.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'arch/arm/mm/fault-armv.c') 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) { -- cgit v1.2.2 From 6012191aa9c6ffff3a23b81162298318b56d7cb3 Mon Sep 17 00:00:00 2001 From: Catalin Marinas Date: Mon, 13 Sep 2010 15:58:06 +0100 Subject: ARM: 6380/1: Introduce __sync_icache_dcache() for VIPT caches On SMP systems, there is a small chance of a PTE becoming visible to a different CPU before the current cache maintenance operations in update_mmu_cache(). To avoid this, cache maintenance must be handled in set_pte_at() (similar to IA-64 and PowerPC). This patch provides a unified VIPT cache handling mechanism and implements the __sync_icache_dcache() function for ARMv6 onwards architectures. It is called from set_pte_at() and replaces the update_mmu_cache(). The latter is still used on VIVT hardware where a vm_area_struct is required. Tested-by: Rabin Vincent Cc: Nicolas Pitre Signed-off-by: Catalin Marinas Signed-off-by: Russell King --- arch/arm/mm/fault-armv.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'arch/arm/mm/fault-armv.c') diff --git a/arch/arm/mm/fault-armv.c b/arch/arm/mm/fault-armv.c index 58846cbd0e0b..8440d952ba6d 100644 --- a/arch/arm/mm/fault-armv.c +++ b/arch/arm/mm/fault-armv.c @@ -28,6 +28,7 @@ static unsigned long shared_pte_mask = L_PTE_MT_BUFFERABLE; +#if __LINUX_ARM_ARCH__ < 6 /* * We take the easy way out of this problem - we make the * PTE uncacheable. However, we leave the write buffer on. @@ -168,10 +169,8 @@ void update_mmu_cache(struct vm_area_struct *vma, unsigned long addr, return; mapping = page_mapping(page); -#ifndef CONFIG_SMP if (!test_and_set_bit(PG_dcache_clean, &page->flags)) __flush_dcache_page(mapping, page); -#endif if (mapping) { if (cache_is_vivt()) make_coherent(mapping, vma, addr, ptep, pfn); @@ -179,6 +178,7 @@ void update_mmu_cache(struct vm_area_struct *vma, unsigned long addr, __flush_icache_all(); } } +#endif /* __LINUX_ARM_ARCH__ < 6 */ /* * Check whether the write buffer has physical address aliasing -- cgit v1.2.2