diff options
Diffstat (limited to 'arch/arm/mm/fault-armv.c')
| -rw-r--r-- | arch/arm/mm/fault-armv.c | 14 |
1 files changed, 11 insertions, 3 deletions
diff --git a/arch/arm/mm/fault-armv.c b/arch/arm/mm/fault-armv.c index d0d17b6a370..56ee15321b0 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; /* @@ -151,7 +153,14 @@ 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); #ifndef CONFIG_SMP if (test_and_clear_bit(PG_dcache_dirty, &page->flags)) @@ -198,9 +207,8 @@ void __init check_writebuffer_bugs(void) page = alloc_page(GFP_KERNEL); if (page) { unsigned long *p1, *p2; - pgprot_t prot = __pgprot(L_PTE_PRESENT|L_PTE_YOUNG| - L_PTE_DIRTY|L_PTE_WRITE| - L_PTE_MT_BUFFERABLE); + pgprot_t prot = __pgprot_modify(PAGE_KERNEL, + L_PTE_MT_MASK, L_PTE_MT_BUFFERABLE); p1 = vmap(&page, 1, VM_IOREMAP, prot); p2 = vmap(&page, 1, VM_IOREMAP, prot); |