diff options
Diffstat (limited to 'arch/arm/mm/fault-armv.c')
| -rw-r--r-- | arch/arm/mm/fault-armv.c | 18 |
1 files changed, 12 insertions, 6 deletions
diff --git a/arch/arm/mm/fault-armv.c b/arch/arm/mm/fault-armv.c index bc0099d5ae8..72960229195 100644 --- a/arch/arm/mm/fault-armv.c +++ b/arch/arm/mm/fault-armv.c @@ -23,6 +23,8 @@ #include <asm/pgtable.h> #include <asm/tlbflush.h> +#include "mm.h" + static unsigned long shared_pte_mask = L_PTE_MT_BUFFERABLE; /* @@ -151,16 +153,20 @@ void update_mmu_cache(struct vm_area_struct *vma, unsigned long addr, pte_t pte) if (!pfn_valid(pfn)) return; + /* + * The zero page is never written to, so never has any dirty + * cache lines, and therefore never needs to be flushed. + */ page = pfn_to_page(pfn); + if (page == ZERO_PAGE(0)) + return; + mapping = page_mapping(page); - if (mapping) { #ifndef CONFIG_SMP - int dirty = test_and_clear_bit(PG_dcache_dirty, &page->flags); - - if (dirty) - __flush_dcache_page(mapping, page); + if (test_and_clear_bit(PG_dcache_dirty, &page->flags)) + __flush_dcache_page(mapping, page); #endif - + if (mapping) { if (cache_is_vivt()) make_coherent(mapping, vma, addr, pfn); else if (vma->vm_flags & VM_EXEC) |