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Diffstat (limited to 'arch/mips/include/asm/pgtable-64.h')
| -rw-r--r-- | arch/mips/include/asm/pgtable-64.h | 253 |
1 files changed, 253 insertions, 0 deletions
diff --git a/arch/mips/include/asm/pgtable-64.h b/arch/mips/include/asm/pgtable-64.h new file mode 100644 index 0000000..943515f --- /dev/null +++ b/arch/mips/include/asm/pgtable-64.h @@ -0,0 +1,253 @@ +/* + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * Copyright (C) 1994, 95, 96, 97, 98, 99, 2000, 2003 Ralf Baechle + * Copyright (C) 1999, 2000, 2001 Silicon Graphics, Inc. + */ +#ifndef _ASM_PGTABLE_64_H +#define _ASM_PGTABLE_64_H + +#include <linux/linkage.h> + +#include <asm/addrspace.h> +#include <asm/page.h> +#include <asm/cachectl.h> +#include <asm/fixmap.h> + +#include <asm-generic/pgtable-nopud.h> + +/* + * Each address space has 2 4K pages as its page directory, giving 1024 + * (== PTRS_PER_PGD) 8 byte pointers to pmd tables. Each pmd table is a + * single 4K page, giving 512 (== PTRS_PER_PMD) 8 byte pointers to page + * tables. Each page table is also a single 4K page, giving 512 (== + * PTRS_PER_PTE) 8 byte ptes. Each pud entry is initialized to point to + * invalid_pmd_table, each pmd entry is initialized to point to + * invalid_pte_table, each pte is initialized to 0. When memory is low, + * and a pmd table or a page table allocation fails, empty_bad_pmd_table + * and empty_bad_page_table is returned back to higher layer code, so + * that the failure is recognized later on. Linux does not seem to + * handle these failures very well though. The empty_bad_page_table has + * invalid pte entries in it, to force page faults. + * + * Kernel mappings: kernel mappings are held in the swapper_pg_table. + * The layout is identical to userspace except it's indexed with the + * fault address - VMALLOC_START. + */ + +/* PMD_SHIFT determines the size of the area a second-level page table can map */ +#define PMD_SHIFT (PAGE_SHIFT + (PAGE_SHIFT + PTE_ORDER - 3)) +#define PMD_SIZE (1UL << PMD_SHIFT) +#define PMD_MASK (~(PMD_SIZE-1)) + +/* PGDIR_SHIFT determines what a third-level page table entry can map */ +#define PGDIR_SHIFT (PMD_SHIFT + (PAGE_SHIFT + PMD_ORDER - 3)) +#define PGDIR_SIZE (1UL << PGDIR_SHIFT) +#define PGDIR_MASK (~(PGDIR_SIZE-1)) + +/* + * For 4kB page size we use a 3 level page tree and an 8kB pud, which + * permits us mapping 40 bits of virtual address space. + * + * We used to implement 41 bits by having an order 1 pmd level but that seemed + * rather pointless. + * + * For 8kB page size we use a 3 level page tree which permits a total of + * 8TB of address space. Alternatively a 33-bit / 8GB organization using + * two levels would be easy to implement. + * + * For 16kB page size we use a 2 level page tree which permits a total of + * 36 bits of virtual address space. We could add a third level but it seems + * like at the moment there's no need for this. + * + * For 64kB page size we use a 2 level page table tree for a total of 42 bits + * of virtual address space. + */ +#ifdef CONFIG_PAGE_SIZE_4KB +#define PGD_ORDER 1 +#define PUD_ORDER aieeee_attempt_to_allocate_pud +#define PMD_ORDER 0 +#define PTE_ORDER 0 +#endif +#ifdef CONFIG_PAGE_SIZE_8KB +#define PGD_ORDER 0 +#define PUD_ORDER aieeee_attempt_to_allocate_pud +#define PMD_ORDER 0 +#define PTE_ORDER 0 +#endif +#ifdef CONFIG_PAGE_SIZE_16KB +#define PGD_ORDER 0 +#define PUD_ORDER aieeee_attempt_to_allocate_pud +#define PMD_ORDER 0 +#define PTE_ORDER 0 +#endif +#ifdef CONFIG_PAGE_SIZE_64KB +#define PGD_ORDER 0 +#define PUD_ORDER aieeee_attempt_to_allocate_pud +#define PMD_ORDER 0 +#define PTE_ORDER 0 +#endif + +#define PTRS_PER_PGD ((PAGE_SIZE << PGD_ORDER) / sizeof(pgd_t)) +#define PTRS_PER_PMD ((PAGE_SIZE << PMD_ORDER) / sizeof(pmd_t)) +#define PTRS_PER_PTE ((PAGE_SIZE << PTE_ORDER) / sizeof(pte_t)) + +#if PGDIR_SIZE >= TASK_SIZE +#define USER_PTRS_PER_PGD (1) +#else +#define USER_PTRS_PER_PGD (TASK_SIZE / PGDIR_SIZE) +#endif +#define FIRST_USER_ADDRESS 0UL + +#define VMALLOC_START MAP_BASE +#define VMALLOC_END \ + (VMALLOC_START + PTRS_PER_PGD * PTRS_PER_PMD * PTRS_PER_PTE * PAGE_SIZE) +#if defined(CONFIG_MODULES) && defined(KBUILD_64BIT_SYM32) && \ + VMALLOC_START != CKSSEG +/* Load modules into 32bit-compatible segment. */ +#define MODULE_START CKSSEG +#define MODULE_END (FIXADDR_START-2*PAGE_SIZE) +extern pgd_t module_pg_dir[PTRS_PER_PGD]; +#endif + +#define pte_ERROR(e) \ + printk("%s:%d: bad pte %016lx.\n", __FILE__, __LINE__, pte_val(e)) +#define pmd_ERROR(e) \ + printk("%s:%d: bad pmd %016lx.\n", __FILE__, __LINE__, pmd_val(e)) +#define pgd_ERROR(e) \ + printk("%s:%d: bad pgd %016lx.\n", __FILE__, __LINE__, pgd_val(e)) + +extern pte_t invalid_pte_table[PTRS_PER_PTE]; +extern pte_t empty_bad_page_table[PTRS_PER_PTE]; +extern pmd_t invalid_pmd_table[PTRS_PER_PMD]; +extern pmd_t empty_bad_pmd_table[PTRS_PER_PMD]; + +/* + * Empty pgd/pmd entries point to the invalid_pte_table. + */ +static inline int pmd_none(pmd_t pmd) +{ + return pmd_val(pmd) == (unsigned long) invalid_pte_table; +} + +#define pmd_bad(pmd) (pmd_val(pmd) & ~PAGE_MASK) + +static inline int pmd_present(pmd_t pmd) +{ + return pmd_val(pmd) != (unsigned long) invalid_pte_table; +} + +static inline void pmd_clear(pmd_t *pmdp) +{ + pmd_val(*pmdp) = ((unsigned long) invalid_pte_table); +} + +/* + * Empty pud entries point to the invalid_pmd_table. + */ +static inline int pud_none(pud_t pud) +{ + return pud_val(pud) == (unsigned long) invalid_pmd_table; +} + +static inline int pud_bad(pud_t pud) +{ + return pud_val(pud) & ~PAGE_MASK; +} + +static inline int pud_present(pud_t pud) +{ + return pud_val(pud) != (unsigned long) invalid_pmd_table; +} + +static inline void pud_clear(pud_t *pudp) +{ + pud_val(*pudp) = ((unsigned long) invalid_pmd_table); +} + +#define pte_page(x) pfn_to_page(pte_pfn(x)) + +#ifdef CONFIG_CPU_VR41XX +#define pte_pfn(x) ((unsigned long)((x).pte >> (PAGE_SHIFT + 2))) +#define pfn_pte(pfn, prot) __pte(((pfn) << (PAGE_SHIFT + 2)) | pgprot_val(prot)) +#else +#define pte_pfn(x) ((unsigned long)((x).pte >> PAGE_SHIFT)) +#define pfn_pte(pfn, prot) __pte(((pfn) << PAGE_SHIFT) | pgprot_val(prot)) +#endif + +#define __pgd_offset(address) pgd_index(address) +#define __pud_offset(address) (((address) >> PUD_SHIFT) & (PTRS_PER_PUD-1)) +#define __pmd_offset(address) pmd_index(address) + +/* to find an entry in a kernel page-table-directory */ +#ifdef MODULE_START +#define pgd_offset_k(address) \ + ((address) >= MODULE_START ? module_pg_dir : pgd_offset(&init_mm, 0UL)) +#else +#define pgd_offset_k(address) pgd_offset(&init_mm, 0UL) +#endif + +#define pgd_index(address) (((address) >> PGDIR_SHIFT) & (PTRS_PER_PGD-1)) +#define pmd_index(address) (((address) >> PMD_SHIFT) & (PTRS_PER_PMD-1)) + +/* to find an entry in a page-table-directory */ +#define pgd_offset(mm, addr) ((mm)->pgd + pgd_index(addr)) + +static inline unsigned long pud_page_vaddr(pud_t pud) +{ + return pud_val(pud); +} +#define pud_phys(pud) virt_to_phys((void *)pud_val(pud)) +#define pud_page(pud) (pfn_to_page(pud_phys(pud) >> PAGE_SHIFT)) + +/* Find an entry in the second-level page table.. */ +static inline pmd_t *pmd_offset(pud_t * pud, unsigned long address) +{ + return (pmd_t *) pud_page_vaddr(*pud) + pmd_index(address); +} + +/* Find an entry in the third-level page table.. */ +#define __pte_offset(address) \ + (((address) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1)) +#define pte_offset(dir, address) \ + ((pte_t *) pmd_page_vaddr(*(dir)) + __pte_offset(address)) +#define pte_offset_kernel(dir, address) \ + ((pte_t *) pmd_page_vaddr(*(dir)) + __pte_offset(address)) +#define pte_offset_map(dir, address) \ + ((pte_t *)page_address(pmd_page(*(dir))) + __pte_offset(address)) +#define pte_offset_map_nested(dir, address) \ + ((pte_t *)page_address(pmd_page(*(dir))) + __pte_offset(address)) +#define pte_unmap(pte) ((void)(pte)) +#define pte_unmap_nested(pte) ((void)(pte)) + +/* + * Initialize a new pgd / pmd table with invalid pointers. + */ +extern void pgd_init(unsigned long page); +extern void pmd_init(unsigned long page, unsigned long pagetable); + +/* + * Non-present pages: high 24 bits are offset, next 8 bits type, + * low 32 bits zero. + */ +static inline pte_t mk_swap_pte(unsigned long type, unsigned long offset) +{ pte_t pte; pte_val(pte) = (type << 32) | (offset << 40); return pte; } + +#define __swp_type(x) (((x).val >> 32) & 0xff) +#define __swp_offset(x) ((x).val >> 40) +#define __swp_entry(type, offset) ((swp_entry_t) { pte_val(mk_swap_pte((type), (offset))) }) +#define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) }) +#define __swp_entry_to_pte(x) ((pte_t) { (x).val }) + +/* + * Bits 0, 4, 6, and 7 are taken. Let's leave bits 1, 2, 3, and 5 alone to + * make things easier, and only use the upper 56 bits for the page offset... + */ +#define PTE_FILE_MAX_BITS 56 + +#define pte_to_pgoff(_pte) ((_pte).pte >> 8) +#define pgoff_to_pte(off) ((pte_t) { ((off) << 8) | _PAGE_FILE }) + +#endif /* _ASM_PGTABLE_64_H */ |
