pgtable_32.h

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#ifndef _ASM_X86_PGTABLE_32_H
#define _ASM_X86_PGTABLE_32_H

#include <asm/pgtable_32_types.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/list.h>
#include <linux/spinlock.h>

struct mm_struct;
struct vm_area_struct;

extern pgd_t swapper_pg_dir[1024];
extern pgd_t initial_page_table[1024];

static inline void pgtable_cache_init(void) { }
static inline void check_pgt_cache(void) { }
void paging_init(void);

extern void set_pmd_pfn(unsigned long, unsigned long, pgprot_t);


/*
 * 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

#ifdef CONFIG_X86_PAE
# include <asm/pgtable-3level.h>
#else
# include <asm/pgtable-2level.h>
#endif

#if defined(CONFIG_HIGHPTE)
#define pte_offset_map(dir, address)                    \
    ((pte_t *)kmap_atomic(pmd_page(*(dir))) +       \
     pte_index((address)))
#define pte_unmap(pte) kunmap_atomic((pte))
#else
#define pte_offset_map(dir, address)                    \
    ((pte_t *)page_address(pmd_page(*(dir))) + pte_index((address)))
#define pte_unmap(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, ptep) do { } while (0)
#define update_mmu_cache_pmd(vma, address, pmd) 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

#endif /* _ASM_X86_PGTABLE_32_H */