From dbf62d50067e55a782583fe53c3d2a3d98b1f6f3 Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Thu, 19 Jul 2012 11:51:05 +0100 Subject: ARM: mm: introduce L_PTE_VALID for page table entries For long-descriptor translation table formats, the ARMv7 architecture defines the last two bits of the second- and third-level descriptors to be: x0b - Invalid 01b - Block (second-level), Reserved (third-level) 11b - Table (second-level), Page (third-level) This allows us to define L_PTE_PRESENT as (3 << 0) and use this value to create ptes directly. However, when determining whether a given pte value is present in the low-level page table accessors, we only need to check the least significant bit of the descriptor, allowing us to write faulting, present entries which are required for PROT_NONE mappings. This patch introduces L_PTE_VALID, which can be used to test whether a pte should fault, and updates the low-level page table accessors accordingly. Signed-off-by: Will Deacon --- arch/arm/include/asm/pgtable.h | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) (limited to 'arch/arm/include/asm/pgtable.h') diff --git a/arch/arm/include/asm/pgtable.h b/arch/arm/include/asm/pgtable.h index 08c12312a1f9..ccf34b6e9903 100644 --- a/arch/arm/include/asm/pgtable.h +++ b/arch/arm/include/asm/pgtable.h @@ -203,9 +203,7 @@ static inline pte_t *pmd_page_vaddr(pmd_t pmd) #define pte_exec(pte) (!(pte_val(pte) & L_PTE_XN)) #define pte_special(pte) (0) -#define pte_present_user(pte) \ - ((pte_val(pte) & (L_PTE_PRESENT | L_PTE_USER)) == \ - (L_PTE_PRESENT | L_PTE_USER)) +#define pte_present_user(pte) (pte_present(pte) && (pte_val(pte) & L_PTE_USER)) #if __LINUX_ARM_ARCH__ < 6 static inline void __sync_icache_dcache(pte_t pteval) -- cgit v1.2.3