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Diffstat (limited to 'include/asm-mips/pgtable-64.h')
| -rw-r--r-- | include/asm-mips/pgtable-64.h | 227 |
1 files changed, 227 insertions, 0 deletions
diff --git a/include/asm-mips/pgtable-64.h b/include/asm-mips/pgtable-64.h new file mode 100644 index 0000000..704b551 --- /dev/null +++ b/include/asm-mips/pgtable-64.h @@ -0,0 +1,227 @@ +/* + * 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/config.h> +#include <linux/linkage.h> + +#include <asm/addrspace.h> +#include <asm/page.h> +#include <asm/cachectl.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 + * pair of 4K pages, giving 1024 (== PTRS_PER_PMD) 8 byte pointers to + * page tables. Each page table is a single 4K page, giving 512 (== + * PTRS_PER_PTE) 8 byte ptes. Each pgde is initialized to point to + * invalid_pmd_table, each pmde 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 - 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 + 1 - 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 a 8kB pmd and pgds 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 leve. 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 PMD_ORDER 0 +#define PTE_ORDER 0 +#endif +#ifdef CONFIG_PAGE_SIZE_8KB +#define PGD_ORDER 0 +#define PMD_ORDER 0 +#define PTE_ORDER 0 +#endif +#ifdef CONFIG_PAGE_SIZE_16KB +#define PGD_ORDER 0 +#define PMD_ORDER 0 +#define PTE_ORDER 0 +#endif +#ifdef CONFIG_PAGE_SIZE_64KB +#define PGD_ORDER 0 +#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)) + +#define USER_PTRS_PER_PGD (TASK_SIZE / PGDIR_SIZE) +#define FIRST_USER_PGD_NR 0 + +#define VMALLOC_START XKSEG +#define VMALLOC_END \ + (VMALLOC_START + PTRS_PER_PGD * PTRS_PER_PMD * PTRS_PER_PTE * PAGE_SIZE) + +#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[PAGE_SIZE/sizeof(pte_t)]; +extern pte_t empty_bad_page_table[PAGE_SIZE/sizeof(pte_t)]; +extern pmd_t invalid_pmd_table[2*PAGE_SIZE/sizeof(pmd_t)]; +extern pmd_t empty_bad_pmd_table[2*PAGE_SIZE/sizeof(pmd_t)]; + +/* + * Empty 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 pgd entries point to the invalid_pmd_table. + */ +static inline int pgd_none(pgd_t pgd) +{ + return pgd_val(pgd) == (unsigned long) invalid_pmd_table; +} + +#define pgd_bad(pgd) (pgd_val(pgd) &~ PAGE_MASK) + +static inline int pgd_present(pgd_t pgd) +{ + return pgd_val(pgd) != (unsigned long) invalid_pmd_table; +} + +static inline void pgd_clear(pgd_t *pgdp) +{ + pgd_val(*pgdp) = ((unsigned long) invalid_pmd_table); +} + +#define pte_page(x) pfn_to_page((unsigned long)((pte_val(x) >> PAGE_SHIFT))) +#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 page_pte(page) page_pte_prot(page, __pgprot(0)) + +/* to find an entry in a kernel page-table-directory */ +#define pgd_offset_k(address) pgd_offset(&init_mm, 0) + +#define pgd_index(address) ((address) >> PGDIR_SHIFT) + +/* to find an entry in a page-table-directory */ +#define pgd_offset(mm,addr) ((mm)->pgd + pgd_index(addr)) + +static inline unsigned long pgd_page(pgd_t pgd) +{ + return pgd_val(pgd); +} + +/* Find an entry in the second-level page table.. */ +static inline pmd_t *pmd_offset(pgd_t * dir, unsigned long address) +{ + return (pmd_t *) pgd_page(*dir) + + ((address >> PMD_SHIFT) & (PTRS_PER_PMD - 1)); +} + +/* 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_kernel(*dir)) + __pte_offset(address)) +#define pte_offset_kernel(dir, address) \ + ((pte_t *) pmd_page_kernel(*(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, 1, 2, 7 and 8 are taken, split up the 32 bits of offset + * into this range: + */ +#define PTE_FILE_MAX_BITS 32 + +#define pte_to_pgoff(_pte) \ + ((((_pte).pte >> 3) & 0x1f ) + (((_pte).pte >> 9) << 6 )) + +#define pgoff_to_pte(off) \ + ((pte_t) { (((off) & 0x1f) << 3) + (((off) >> 6) << 9) + _PAGE_FILE }) + +#endif /* _ASM_PGTABLE_64_H */ |