From 8830f04a092b47f3d246271b24685cd9eab82027 Mon Sep 17 00:00:00 2001 From: Russell King Date: Mon, 20 Jun 2005 09:51:03 +0100 Subject: [PATCH] [PATCH] ARM: Fix delayed dcache flush for ARMv6 non-aliasing caches flush_dcache_page() did nothing for these caches, but since they suffer from I/D cache coherency issues, we need to ensure that data is written back to RAM. Signed-off-by: Russell King --- arch/arm/mm/fault-armv.c | 31 ++++++++++------------------ arch/arm/mm/flush.c | 44 ++++++++++++++++------------------------ 2 files changed, 29 insertions(+), 46 deletions(-) diff --git a/arch/arm/mm/fault-armv.c b/arch/arm/mm/fault-armv.c index 01967ddeef53..be4ab3d73c91 100644 --- a/arch/arm/mm/fault-armv.c +++ b/arch/arm/mm/fault-armv.c @@ -77,9 +77,8 @@ no_pmd: } static void -make_coherent(struct vm_area_struct *vma, unsigned long addr, struct page *page, int dirty) +make_coherent(struct address_space *mapping, struct vm_area_struct *vma, unsigned long addr, unsigned long pfn) { - struct address_space *mapping = page_mapping(page); struct mm_struct *mm = vma->vm_mm; struct vm_area_struct *mpnt; struct prio_tree_iter iter; @@ -87,9 +86,6 @@ make_coherent(struct vm_area_struct *vma, unsigned long addr, struct page *page, pgoff_t pgoff; int aliases = 0; - if (!mapping) - return; - pgoff = vma->vm_pgoff + ((addr - vma->vm_start) >> PAGE_SHIFT); /* @@ -115,9 +111,11 @@ make_coherent(struct vm_area_struct *vma, unsigned long addr, struct page *page, if (aliases) adjust_pte(vma, addr); else - flush_cache_page(vma, addr, page_to_pfn(page)); + flush_cache_page(vma, addr, pfn); } +void __flush_dcache_page(struct address_space *mapping, struct page *page); + /* * Take care of architecture specific things when placing a new PTE into * a page table, or changing an existing PTE. Basically, there are two @@ -134,29 +132,22 @@ make_coherent(struct vm_area_struct *vma, unsigned long addr, struct page *page, void update_mmu_cache(struct vm_area_struct *vma, unsigned long addr, pte_t pte) { unsigned long pfn = pte_pfn(pte); + struct address_space *mapping; struct page *page; if (!pfn_valid(pfn)) return; + page = pfn_to_page(pfn); - if (page_mapping(page)) { + mapping = page_mapping(page); + if (mapping) { int dirty = test_and_clear_bit(PG_dcache_dirty, &page->flags); - if (dirty) { - /* - * This is our first userspace mapping of this page. - * Ensure that the physical page is coherent with - * the kernel mapping. - * - * FIXME: only need to do this on VIVT and aliasing - * VIPT cache architectures. We can do that - * by choosing whether to set this bit... - */ - __cpuc_flush_dcache_page(page_address(page)); - } + if (dirty) + __flush_dcache_page(mapping, page); if (cache_is_vivt()) - make_coherent(vma, addr, page, dirty); + make_coherent(mapping, vma, addr, pfn); } } diff --git a/arch/arm/mm/flush.c b/arch/arm/mm/flush.c index 4085ed983e46..191788fb18d1 100644 --- a/arch/arm/mm/flush.c +++ b/arch/arm/mm/flush.c @@ -37,13 +37,8 @@ static void flush_pfn_alias(unsigned long pfn, unsigned long vaddr) #define flush_pfn_alias(pfn,vaddr) do { } while (0) #endif -static void __flush_dcache_page(struct address_space *mapping, struct page *page) +void __flush_dcache_page(struct address_space *mapping, struct page *page) { - struct mm_struct *mm = current->active_mm; - struct vm_area_struct *mpnt; - struct prio_tree_iter iter; - pgoff_t pgoff; - /* * Writeback any data associated with the kernel mapping of this * page. This ensures that data in the physical page is mutually @@ -52,24 +47,21 @@ static void __flush_dcache_page(struct address_space *mapping, struct page *page __cpuc_flush_dcache_page(page_address(page)); /* - * If there's no mapping pointer here, then this page isn't - * visible to userspace yet, so there are no cache lines - * associated with any other aliases. - */ - if (!mapping) - return; - - /* - * This is a page cache page. If we have a VIPT cache, we - * only need to do one flush - which would be at the relevant + * If this is a page cache page, and we have an aliasing VIPT cache, + * we only need to do one flush - which would be at the relevant * userspace colour, which is congruent with page->index. */ - if (cache_is_vipt()) { - if (cache_is_vipt_aliasing()) - flush_pfn_alias(page_to_pfn(page), - page->index << PAGE_CACHE_SHIFT); - return; - } + if (mapping && cache_is_vipt_aliasing()) + flush_pfn_alias(page_to_pfn(page), + page->index << PAGE_CACHE_SHIFT); +} + +static void __flush_dcache_aliases(struct address_space *mapping, struct page *page) +{ + struct mm_struct *mm = current->active_mm; + struct vm_area_struct *mpnt; + struct prio_tree_iter iter; + pgoff_t pgoff; /* * There are possible user space mappings of this page: @@ -116,12 +108,12 @@ void flush_dcache_page(struct page *page) { struct address_space *mapping = page_mapping(page); - if (cache_is_vipt_nonaliasing()) - return; - if (mapping && !mapping_mapped(mapping)) set_bit(PG_dcache_dirty, &page->flags); - else + else { __flush_dcache_page(mapping, page); + if (mapping && cache_is_vivt()) + __flush_dcache_aliases(mapping, page); + } } EXPORT_SYMBOL(flush_dcache_page); -- 2.30.2