From d30e45eeabefadc6039d7f876a59e5f5f6cb11c6 Mon Sep 17 00:00:00 2001 From: Russell King Date: Tue, 16 Nov 2010 00:16:01 +0000 Subject: ARM: pgtable: switch order of Linux vs hardware page tables This switches the ordering of the Linux vs hardware page tables in each page, thereby eliminating some of the arithmetic in the page table walks. As we now place the Linux page table at the beginning of the page, we can deal with the offset in the pgt by simply masking it away, along with the other control bits. This also makes the arithmetic all be positive, rather than a mixture. Signed-off-by: Russell King --- arch/arm/include/asm/pgtable.h | 31 +++++++++++++++---------------- 1 file changed, 15 insertions(+), 16 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 50eb0b4278ec..e582214b00df 100644 --- a/arch/arm/include/asm/pgtable.h +++ b/arch/arm/include/asm/pgtable.h @@ -55,7 +55,7 @@ * Therefore, we tweak the implementation slightly - we tell Linux that we * have 2048 entries in the first level, each of which is 8 bytes (iow, two * hardware pointers to the second level.) The second level contains two - * hardware PTE tables arranged contiguously, followed by Linux versions + * hardware PTE tables arranged contiguously, preceded by Linux versions * which contain the state information Linux needs. We, therefore, end up * with 512 entries in the "PTE" level. * @@ -63,15 +63,15 @@ * * pgd pte * | | - * +--------+ +0 - * | |-----> +------------+ +0 + * +--------+ + * | | +------------+ +0 + * +- - - - + | Linux pt 0 | + * | | +------------+ +1024 + * +--------+ +0 | Linux pt 1 | + * | |-----> +------------+ +2048 * +- - - - + +4 | h/w pt 0 | - * | |-----> +------------+ +1024 + * | |-----> +------------+ +3072 * +--------+ +8 | h/w pt 1 | - * | | +------------+ +2048 - * +- - - - + | Linux pt 0 | - * | | +------------+ +3072 - * +--------+ | Linux pt 1 | * | | +------------+ +4096 * * See L_PTE_xxx below for definitions of bits in the "Linux pt", and @@ -103,6 +103,10 @@ #define PTRS_PER_PMD 1 #define PTRS_PER_PGD 2048 +#define PTE_HWTABLE_PTRS (PTRS_PER_PTE) +#define PTE_HWTABLE_OFF (PTE_HWTABLE_PTRS * sizeof(pte_t)) +#define PTE_HWTABLE_SIZE (PTRS_PER_PTE * sizeof(u32)) + /* * PMD_SHIFT determines the size of the area a second-level page table can map * PGDIR_SHIFT determines what a third-level page table entry can map @@ -323,12 +327,7 @@ extern pgd_t swapper_pg_dir[PTRS_PER_PGD]; static inline pte_t *pmd_page_vaddr(pmd_t pmd) { - phys_addr_t ptr; - - ptr = pmd_val(pmd) & ~(PTRS_PER_PTE * sizeof(void *) - 1); - ptr += PTRS_PER_PTE * sizeof(void *); - - return __va(ptr); + return __va(pmd_val(pmd) & PAGE_MASK); } #define pmd_page(pmd) pfn_to_page(__phys_to_pfn(pmd_val(pmd))) @@ -341,8 +340,8 @@ static inline pte_t *pmd_page_vaddr(pmd_t pmd) #define __pte_map(pmd) pmd_page_vaddr(*(pmd)) #define __pte_unmap(pte) do { } while (0) #else -#define __pte_map(pmd) ((pte_t *)kmap_atomic(pmd_page(*(pmd))) + PTRS_PER_PTE) -#define __pte_unmap(pte) kunmap_atomic((pte - PTRS_PER_PTE)) +#define __pte_map(pmd) (pte_t *)kmap_atomic(pmd_page(*(pmd))) +#define __pte_unmap(pte) kunmap_atomic(pte) #endif #define pte_index(addr) (((addr) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1)) -- cgit v1.2.3