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linux/include/asm-i386/pgtable.h
Hugh Dickins d455a3696c [PATCH] freepgt: arch FIRST_USER_ADDRESS 0 
Replace misleading definition of FIRST_USER_PGD_NR 0 by definition of
FIRST_USER_ADDRESS 0 in all the MMU architectures beyond arm and arm26.

Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-04-19 13:29:23 -07:00

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#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
/*
* The 4MB page is guessing.. Detailed in the infamous "Chapter H"
* of the Pentium details, but assuming intel did the straightforward
* thing, this bit 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
#define _PAGE_FILE 0x040 /* set:pagecache unset:swap */
#define _PAGE_PROTNONE 0x080 /* If not present */
#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 'verify_area(VERIFY_WRITE,..)'
*/
#undef TEST_VERIFY_AREA
/* 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..
*/
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; }
/*
* 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; }
#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 void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
{
clear_bit(_PAGE_BIT_RW, &ptep->pte_low);
}
/*
* 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))
#define mk_pte_huge(entry) ((entry).pte_low |= _PAGE_PRESENT | _PAGE_PSE)
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__ */
#ifndef CONFIG_DISCONTIGMEM
#define kern_addr_valid(addr) (1)
#endif /* !CONFIG_DISCONTIGMEM */
#define io_remap_page_range(vma, vaddr, paddr, size, prot) \
remap_pfn_range(vma, vaddr, (paddr) >> PAGE_SHIFT, size, prot)
#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_SET_WRPROTECT
#define __HAVE_ARCH_PTE_SAME
#include <asm-generic/pgtable.h>
#endif /* _I386_PGTABLE_H */
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