#ifndef _I386_PGTABLE_H #define _I386_PGTABLE_H /* * The Linux memory management assumes a three-level page table setup. On * the i386, we use that, but "fold" the mid level into the top-level page * table, so that we physically have the same two-level page table as the * i386 mmu expects. * * This file contains the functions and defines necessary to modify and use * the i386 page table tree. */ #ifndef __ASSEMBLY__ #include <asm/processor.h> #include <asm/fixmap.h> #include <linux/threads.h> #include <asm/paravirt.h> #include <linux/bitops.h> #include <linux/slab.h> #include <linux/list.h> #include <linux/spinlock.h> struct mm_struct; struct vm_area_struct; extern pgd_t swapper_pg_dir[1024]; static inline void pgtable_cache_init(void) { } static inline void check_pgt_cache(void) { } void paging_init(void); /* * The Linux x86 paging architecture is 'compile-time dual-mode', it * implements both the traditional 2-level x86 page tables and the * newer 3-level PAE-mode page tables. */ #ifdef CONFIG_X86_PAE # include <asm/pgtable-3level-defs.h> # define PMD_SIZE (1UL << PMD_SHIFT) # define PMD_MASK (~(PMD_SIZE - 1)) #else # include <asm/pgtable-2level-defs.h> #endif #define PGDIR_SIZE (1UL << PGDIR_SHIFT) #define PGDIR_MASK (~(PGDIR_SIZE - 1)) /* Just any arbitrary offset to the start of the vmalloc VM area: the * current 8MB value just means that there will be a 8MB "hole" after the * physical memory until the kernel virtual memory starts. That means that * any out-of-bounds memory accesses will hopefully be caught. * The vmalloc() routines leaves a hole of 4kB between each vmalloced * area for the same reason. ;) */ #define VMALLOC_OFFSET (8 * 1024 * 1024) #define VMALLOC_START (((unsigned long)high_memory + 2 * VMALLOC_OFFSET - 1) \ & ~(VMALLOC_OFFSET - 1)) #ifdef CONFIG_X86_PAE #define LAST_PKMAP 512 #else #define LAST_PKMAP 1024 #endif #define PKMAP_BASE ((FIXADDR_BOOT_START - PAGE_SIZE * (LAST_PKMAP + 1)) \ & PMD_MASK) #ifdef CONFIG_HIGHMEM # define VMALLOC_END (PKMAP_BASE - 2 * PAGE_SIZE) #else # define VMALLOC_END (FIXADDR_START - 2 * PAGE_SIZE) #endif /* * Define this if things work differently on an i386 and an i486: * it will (on an i486) warn about kernel memory accesses that are * done without a 'access_ok(VERIFY_WRITE,..)' */ #undef TEST_ACCESS_OK /* The boot page tables (all created as a single array) */ extern unsigned long pg0[]; #define pte_present(x) ((x).pte_low & (_PAGE_PRESENT | _PAGE_PROTNONE)) /* To avoid harmful races, pmd_none(x) should check only the lower when PAE */ #define pmd_none(x) (!(unsigned long)pmd_val((x))) #define pmd_present(x) (pmd_val((x)) & _PAGE_PRESENT) #define pmd_bad(x) ((pmd_val(x) & (PTE_FLAGS_MASK & ~_PAGE_USER)) != _KERNPG_TABLE) #define pages_to_mb(x) ((x) >> (20-PAGE_SHIFT)) #ifdef CONFIG_X86_PAE # include <asm/pgtable-3level.h> #else # include <asm/pgtable-2level.h> #endif /* * Macro to mark a page protection value as "uncacheable". * On processors which do not support it, this is a no-op. */ #define pgprot_noncached(prot) \ ((boot_cpu_data.x86 > 3) \ ? (__pgprot(pgprot_val(prot) | _PAGE_PCD | _PAGE_PWT)) \ : (prot)) /* * Conversion functions: convert a page and protection to a page entry, * and a page entry and page directory to the page they refer to. */ #define mk_pte(page, pgprot) pfn_pte(page_to_pfn(page), (pgprot)) static inline int pud_large(pud_t pud) { return 0; } /* * the pmd page can be thought of an array like this: pmd_t[PTRS_PER_PMD] * * this macro returns the index of the entry in the pmd page which would * control the given virtual address */ #define pmd_index(address) \ (((address) >> PMD_SHIFT) & (PTRS_PER_PMD - 1)) /* * the pte page can be thought of an array like this: pte_t[PTRS_PER_PTE] * * this macro returns the index of the entry in the pte page which would * control the given virtual address */ #define pte_index(address) \ (((address) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1)) #define pte_offset_kernel(dir, address) \ ((pte_t *)pmd_page_vaddr(*(dir)) + pte_index((address))) #define pmd_page(pmd) (pfn_to_page(pmd_val((pmd)) >> PAGE_SHIFT)) #define pmd_page_vaddr(pmd) \ ((unsigned long)__va(pmd_val((pmd)) & PTE_PFN_MASK)) #if defined(CONFIG_HIGHPTE) #define pte_offset_map(dir, address) \ ((pte_t *)kmap_atomic_pte(pmd_page(*(dir)), KM_PTE0) + \ pte_index((address))) #define pte_offset_map_nested(dir, address) \ ((pte_t *)kmap_atomic_pte(pmd_page(*(dir)), KM_PTE1) + \ pte_index((address))) #define pte_unmap(pte) kunmap_atomic((pte), KM_PTE0) #define pte_unmap_nested(pte) kunmap_atomic((pte), KM_PTE1) #else #define pte_offset_map(dir, address) \ ((pte_t *)page_address(pmd_page(*(dir))) + pte_index((address))) #define pte_offset_map_nested(dir, address) pte_offset_map((dir), (address)) #define pte_unmap(pte) do { } while (0) #define pte_unmap_nested(pte) do { } while (0) #endif /* Clear a kernel PTE and flush it from the TLB */ #define kpte_clear_flush(ptep, vaddr) \ do { \ pte_clear(&init_mm, (vaddr), (ptep)); \ __flush_tlb_one((vaddr)); \ } while (0) /* * The i386 doesn't have any external MMU info: the kernel page * tables contain all the necessary information. */ #define update_mmu_cache(vma, address, pte) do { } while (0) #endif /* !__ASSEMBLY__ */ /* * kern_addr_valid() is (1) for FLATMEM and (0) for * SPARSEMEM and DISCONTIGMEM */ #ifdef CONFIG_FLATMEM #define kern_addr_valid(addr) (1) #else #define kern_addr_valid(kaddr) (0) #endif #define io_remap_pfn_range(vma, vaddr, pfn, size, prot) \ remap_pfn_range(vma, vaddr, pfn, size, prot) #endif /* _I386_PGTABLE_H */