#ifndef _I386_PGTABLE_H #define _I386_PGTABLE_H #include <linux/config.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> #ifndef _I386_BITOPS_H #include <asm/bitops.h> #endif #include <linux/slab.h> #include <linux/list.h> #include <linux/spinlock.h> /* * ZERO_PAGE is a global shared page that is always zero: used * for zero-mapped memory areas etc.. */ #define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page)) extern unsigned long empty_zero_page[1024]; extern pgd_t swapper_pg_dir[1024]; extern kmem_cache_t *pgd_cache; extern kmem_cache_t *pmd_cache; extern spinlock_t pgd_lock; extern struct page *pgd_list; void pmd_ctor(void *, kmem_cache_t *, unsigned long); void pgd_ctor(void *, kmem_cache_t *, unsigned long); void pgd_dtor(void *, kmem_cache_t *, unsigned long); void pgtable_cache_init(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)) #define USER_PTRS_PER_PGD (TASK_SIZE/PGDIR_SIZE) #define FIRST_USER_ADDRESS 0 #define USER_PGD_PTRS (PAGE_OFFSET >> PGDIR_SHIFT) #define KERNEL_PGD_PTRS (PTRS_PER_PGD-USER_PGD_PTRS) #define TWOLEVEL_PGDIR_SHIFT 22 #define BOOT_USER_PGD_PTRS (__PAGE_OFFSET >> TWOLEVEL_PGDIR_SHIFT) #define BOOT_KERNEL_PGD_PTRS (1024-BOOT_USER_PGD_PTRS) /* 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 + vmalloc_earlyreserve + \ 2*VMALLOC_OFFSET-1) & ~(VMALLOC_OFFSET-1)) #ifdef CONFIG_HIGHMEM # define VMALLOC_END (PKMAP_BASE-2*PAGE_SIZE) #else # define VMALLOC_END (FIXADDR_START-2*PAGE_SIZE) #endif /* * _PAGE_PSE set in the page directory entry just means that * the page directory entry points directly to a 4MB-aligned block of * memory. */ #define _PAGE_BIT_PRESENT 0 #define _PAGE_BIT_RW 1 #define _PAGE_BIT_USER 2 #define _PAGE_BIT_PWT 3 #define _PAGE_BIT_PCD 4 #define _PAGE_BIT_ACCESSED 5 #define _PAGE_BIT_DIRTY 6 #define _PAGE_BIT_PSE 7 /* 4 MB (or 2MB) page, Pentium+, if present.. */ #define _PAGE_BIT_GLOBAL 8 /* Global TLB entry PPro+ */ #define _PAGE_BIT_UNUSED1 9 /* available for programmer */ #define _PAGE_BIT_UNUSED2 10 #define _PAGE_BIT_UNUSED3 11 #define _PAGE_BIT_NX 63 #define _PAGE_PRESENT 0x001 #define _PAGE_RW 0x002 #define _PAGE_USER 0x004 #define _PAGE_PWT 0x008 #define _PAGE_PCD 0x010 #define _PAGE_ACCESSED 0x020 #define _PAGE_DIRTY 0x040 #define _PAGE_PSE 0x080 /* 4 MB (or 2MB) page, Pentium+, if present.. */ #define _PAGE_GLOBAL 0x100 /* Global TLB entry PPro+ */ #define _PAGE_UNUSED1 0x200 /* available for programmer */ #define _PAGE_UNUSED2 0x400 #define _PAGE_UNUSED3 0x800 /* If _PAGE_PRESENT is clear, we use these: */ #define _PAGE_FILE 0x040 /* nonlinear file mapping, saved PTE; unset:swap */ #define _PAGE_PROTNONE 0x080 /* if the user mapped it with PROT_NONE; pte_present gives true */ #ifdef CONFIG_X86_PAE #define _PAGE_NX (1ULL<<_PAGE_BIT_NX) #else #define _PAGE_NX 0 #endif #define _PAGE_TABLE (_PAGE_PRESENT | _PAGE_RW | _PAGE_USER | _PAGE_ACCESSED | _PAGE_DIRTY) #define _KERNPG_TABLE (_PAGE_PRESENT | _PAGE_RW | _PAGE_ACCESSED | _PAGE_DIRTY) #define _PAGE_CHG_MASK (PTE_MASK | _PAGE_ACCESSED | _PAGE_DIRTY) #define PAGE_NONE \ __pgprot(_PAGE_PROTNONE | _PAGE_ACCESSED) #define PAGE_SHARED \ __pgprot(_PAGE_PRESENT | _PAGE_RW | _PAGE_USER | _PAGE_ACCESSED) #define PAGE_SHARED_EXEC \ __pgprot(_PAGE_PRESENT | _PAGE_RW | _PAGE_USER | _PAGE_ACCESSED) #define PAGE_COPY_NOEXEC \ __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_ACCESSED | _PAGE_NX) #define PAGE_COPY_EXEC \ __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_ACCESSED) #define PAGE_COPY \ PAGE_COPY_NOEXEC #define PAGE_READONLY \ __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_ACCESSED | _PAGE_NX) #define PAGE_READONLY_EXEC \ __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_ACCESSED) #define _PAGE_KERNEL \ (_PAGE_PRESENT | _PAGE_RW | _PAGE_DIRTY | _PAGE_ACCESSED | _PAGE_NX) #define _PAGE_KERNEL_EXEC \ (_PAGE_PRESENT | _PAGE_RW | _PAGE_DIRTY | _PAGE_ACCESSED) extern unsigned long long __PAGE_KERNEL, __PAGE_KERNEL_EXEC; #define __PAGE_KERNEL_RO (__PAGE_KERNEL & ~_PAGE_RW) #define __PAGE_KERNEL_NOCACHE (__PAGE_KERNEL | _PAGE_PCD) #define __PAGE_KERNEL_LARGE (__PAGE_KERNEL | _PAGE_PSE) #define __PAGE_KERNEL_LARGE_EXEC (__PAGE_KERNEL_EXEC | _PAGE_PSE) #define PAGE_KERNEL __pgprot(__PAGE_KERNEL) #define PAGE_KERNEL_RO __pgprot(__PAGE_KERNEL_RO) #define PAGE_KERNEL_EXEC __pgprot(__PAGE_KERNEL_EXEC) #define PAGE_KERNEL_NOCACHE __pgprot(__PAGE_KERNEL_NOCACHE) #define PAGE_KERNEL_LARGE __pgprot(__PAGE_KERNEL_LARGE) #define PAGE_KERNEL_LARGE_EXEC __pgprot(__PAGE_KERNEL_LARGE_EXEC) /* * The i386 can't do page protection for execute, and considers that * the same are read. Also, write permissions imply read permissions. * This is the closest we can get.. */ #define __P000 PAGE_NONE #define __P001 PAGE_READONLY #define __P010 PAGE_COPY #define __P011 PAGE_COPY #define __P100 PAGE_READONLY_EXEC #define __P101 PAGE_READONLY_EXEC #define __P110 PAGE_COPY_EXEC #define __P111 PAGE_COPY_EXEC #define __S000 PAGE_NONE #define __S001 PAGE_READONLY #define __S010 PAGE_SHARED #define __S011 PAGE_SHARED #define __S100 PAGE_READONLY_EXEC #define __S101 PAGE_READONLY_EXEC #define __S110 PAGE_SHARED_EXEC #define __S111 PAGE_SHARED_EXEC /* * 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)) #define pte_clear(mm,addr,xp) do { set_pte_at(mm, addr, xp, __pte(0)); } while (0) #define pmd_none(x) (!pmd_val(x)) #define pmd_present(x) (pmd_val(x) & _PAGE_PRESENT) #define pmd_clear(xp) do { set_pmd(xp, __pmd(0)); } while (0) #define pmd_bad(x) ((pmd_val(x) & (~PAGE_MASK & ~_PAGE_USER)) != _KERNPG_TABLE) #define pages_to_mb(x) ((x) >> (20-PAGE_SHIFT)) /* * The following only work if pte_present() is true. * Undefined behaviour if not.. */ #define __LARGE_PTE (_PAGE_PSE | _PAGE_PRESENT) static inline int pte_user(pte_t pte) { return (pte).pte_low & _PAGE_USER; } static inline int pte_read(pte_t pte) { return (pte).pte_low & _PAGE_USER; } static inline int pte_dirty(pte_t pte) { return (pte).pte_low & _PAGE_DIRTY; } static inline int pte_young(pte_t pte) { return (pte).pte_low & _PAGE_ACCESSED; } static inline int pte_write(pte_t pte) { return (pte).pte_low & _PAGE_RW; } static inline int pte_huge(pte_t pte) { return ((pte).pte_low & __LARGE_PTE) == __LARGE_PTE; } /* * The following only works if pte_present() is not true. */ static inline int pte_file(pte_t pte) { return (pte).pte_low & _PAGE_FILE; } static inline pte_t pte_rdprotect(pte_t pte) { (pte).pte_low &= ~_PAGE_USER; return pte; } static inline pte_t pte_exprotect(pte_t pte) { (pte).pte_low &= ~_PAGE_USER; return pte; } static inline pte_t pte_mkclean(pte_t pte) { (pte).pte_low &= ~_PAGE_DIRTY; return pte; } static inline pte_t pte_mkold(pte_t pte) { (pte).pte_low &= ~_PAGE_ACCESSED; return pte; } static inline pte_t pte_wrprotect(pte_t pte) { (pte).pte_low &= ~_PAGE_RW; return pte; } static inline pte_t pte_mkread(pte_t pte) { (pte).pte_low |= _PAGE_USER; return pte; } static inline pte_t pte_mkexec(pte_t pte) { (pte).pte_low |= _PAGE_USER; return pte; } static inline pte_t pte_mkdirty(pte_t pte) { (pte).pte_low |= _PAGE_DIRTY; return pte; } static inline pte_t pte_mkyoung(pte_t pte) { (pte).pte_low |= _PAGE_ACCESSED; return pte; } static inline pte_t pte_mkwrite(pte_t pte) { (pte).pte_low |= _PAGE_RW; return pte; } static inline pte_t pte_mkhuge(pte_t pte) { (pte).pte_low |= __LARGE_PTE; return pte; } #ifdef CONFIG_X86_PAE # include <asm/pgtable-3level.h> #else # include <asm/pgtable-2level.h> #endif static inline int ptep_test_and_clear_dirty(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep) { if (!pte_dirty(*ptep)) return 0; return test_and_clear_bit(_PAGE_BIT_DIRTY, &ptep->pte_low); } static inline int ptep_test_and_clear_young(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep) { if (!pte_young(*ptep)) return 0; return test_and_clear_bit(_PAGE_BIT_ACCESSED, &ptep->pte_low); } static inline pte_t ptep_get_and_clear_full(struct mm_struct *mm, unsigned long addr, pte_t *ptep, int full) { pte_t pte; if (full) { pte = *ptep; *ptep = __pte(0); } else { pte = ptep_get_and_clear(mm, addr, ptep); } return pte; } static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addr, pte_t *ptep) { clear_bit(_PAGE_BIT_RW, &ptep->pte_low); } /* * clone_pgd_range(pgd_t *dst, pgd_t *src, int count); * * dst - pointer to pgd range anwhere on a pgd page * src - "" * count - the number of pgds to copy. * * dst and src can be on the same page, but the range must not overlap, * and must not cross a page boundary. */ static inline void clone_pgd_range(pgd_t *dst, pgd_t *src, int count) { memcpy(dst, src, count * sizeof(pgd_t)); } /* * 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 pte_t pte_modify(pte_t pte, pgprot_t newprot) { pte.pte_low &= _PAGE_CHG_MASK; pte.pte_low |= pgprot_val(newprot); #ifdef CONFIG_X86_PAE /* * Chop off the NX bit (if present), and add the NX portion of * the newprot (if present): */ pte.pte_high &= ~(1 << (_PAGE_BIT_NX - 32)); pte.pte_high |= (pgprot_val(newprot) >> 32) & \ (__supported_pte_mask >> 32); #endif return pte; } #define page_pte(page) page_pte_prot(page, __pgprot(0)) #define pmd_large(pmd) \ ((pmd_val(pmd) & (_PAGE_PSE|_PAGE_PRESENT)) == (_PAGE_PSE|_PAGE_PRESENT)) /* * the pgd page can be thought of an array like this: pgd_t[PTRS_PER_PGD] * * this macro returns the index of the entry in the pgd page which would * control the given virtual address */ #define pgd_index(address) (((address) >> PGDIR_SHIFT) & (PTRS_PER_PGD-1)) #define pgd_index_k(addr) pgd_index(addr) /* * pgd_offset() returns a (pgd_t *) * pgd_index() is used get the offset into the pgd page's array of pgd_t's; */ #define pgd_offset(mm, address) ((mm)->pgd+pgd_index(address)) /* * a shortcut which implies the use of the kernel's pgd, instead * of a process's */ #define pgd_offset_k(address) pgd_offset(&init_mm, address) /* * 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_kernel(*(dir)) + pte_index(address)) /* * Helper function that returns the kernel pagetable entry controlling * the virtual address 'address'. NULL means no pagetable entry present. * NOTE: the return type is pte_t but if the pmd is PSE then we return it * as a pte too. */ extern pte_t *lookup_address(unsigned long address); /* * Make a given kernel text page executable/non-executable. * Returns the previous executability setting of that page (which * is used to restore the previous state). Used by the SMP bootup code. * NOTE: this is an __init function for security reasons. */ #ifdef CONFIG_X86_PAE extern int set_kernel_exec(unsigned long vaddr, int enable); #else static inline int set_kernel_exec(unsigned long vaddr, int enable) { return 0;} #endif extern void noexec_setup(const char *str); #if defined(CONFIG_HIGHPTE) #define pte_offset_map(dir, address) \ ((pte_t *)kmap_atomic(pmd_page(*(dir)),KM_PTE0) + pte_index(address)) #define pte_offset_map_nested(dir, address) \ ((pte_t *)kmap_atomic(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 /* * The i386 doesn't have any external MMU info: the kernel page * tables contain all the necessary information. * * Also, we only update the dirty/accessed state if we set * the dirty bit by hand in the kernel, since the hardware * will do the accessed bit for us, and we don't want to * race with other CPU's that might be updating the dirty * bit at the same time. */ #define update_mmu_cache(vma,address,pte) do { } while (0) #define __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS #define ptep_set_access_flags(__vma, __address, __ptep, __entry, __dirty) \ do { \ if (__dirty) { \ (__ptep)->pte_low = (__entry).pte_low; \ flush_tlb_page(__vma, __address); \ } \ } while (0) #endif /* !__ASSEMBLY__ */ #ifdef CONFIG_FLATMEM #define kern_addr_valid(addr) (1) #endif /* CONFIG_FLATMEM */ #define io_remap_pfn_range(vma, vaddr, pfn, size, prot) \ remap_pfn_range(vma, vaddr, pfn, size, prot) #define MK_IOSPACE_PFN(space, pfn) (pfn) #define GET_IOSPACE(pfn) 0 #define GET_PFN(pfn) (pfn) #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_DIRTY #define __HAVE_ARCH_PTEP_GET_AND_CLEAR #define __HAVE_ARCH_PTEP_GET_AND_CLEAR_FULL #define __HAVE_ARCH_PTEP_SET_WRPROTECT #define __HAVE_ARCH_PTE_SAME #include <asm-generic/pgtable.h> #endif /* _I386_PGTABLE_H */