include/asm-x86/pgtable_64.h

#ifndef _X86_64_PGTABLE_H
#define _X86_64_PGTABLE_H

#include <linux/const.h>
#ifndef __ASSEMBLY__

/*
 * This file contains the functions and defines necessary to modify and use
 * the x86-64 page table tree.
 */
#include <asm/processor.h>
#include <linux/bitops.h>
#include <linux/threads.h>
#include <asm/pda.h>

extern pud_t level3_kernel_pgt[512];
extern pud_t level3_ident_pgt[512];
extern pmd_t level2_kernel_pgt[512];
extern pgd_t init_level4_pgt[];

#define swapper_pg_dir init_level4_pgt

extern void paging_init(void);
extern void clear_kernel_mapping(unsigned long addr, unsigned long size);

/*
 * ZERO_PAGE is a global shared page that is always zero: used
 * for zero-mapped memory areas etc..
 */
extern unsigned long empty_zero_page[PAGE_SIZE/sizeof(unsigned long)];
#define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page))

#endif /* !__ASSEMBLY__ */

/*
 * PGDIR_SHIFT determines what a top-level page table entry can map
 */
#define PGDIR_SHIFT	39
#define PTRS_PER_PGD	512

/*
 * 3rd level page
 */
#define PUD_SHIFT	30
#define PTRS_PER_PUD	512

/*
 * PMD_SHIFT determines the size of the area a middle-level
 * page table can map
 */
#define PMD_SHIFT	21
#define PTRS_PER_PMD	512

/*
 * entries per page directory level
 */
#define PTRS_PER_PTE	512

#ifndef __ASSEMBLY__

#define pte_ERROR(e) \
	printk("%s:%d: bad pte %p(%016lx).\n", __FILE__, __LINE__, &(e), pte_val(e))
#define pmd_ERROR(e) \
	printk("%s:%d: bad pmd %p(%016lx).\n", __FILE__, __LINE__, &(e), pmd_val(e))
#define pud_ERROR(e) \
	printk("%s:%d: bad pud %p(%016lx).\n", __FILE__, __LINE__, &(e), pud_val(e))
#define pgd_ERROR(e) \
	printk("%s:%d: bad pgd %p(%016lx).\n", __FILE__, __LINE__, &(e), pgd_val(e))

#define pgd_none(x)	(!pgd_val(x))
#define pud_none(x)	(!pud_val(x))

static inline void set_pte(pte_t *dst, pte_t val)
{
	*dst = val;
} 
#define set_pte_at(mm,addr,ptep,pteval) set_pte(ptep,pteval)

static inline void set_pmd(pmd_t *dst, pmd_t val)
{
	*dst = val;
} 

static inline void set_pud(pud_t *dst, pud_t val)
{
	*dst = val;
}

static inline void pud_clear (pud_t *pud)
{
	set_pud(pud, __pud(0));
}

static inline void set_pgd(pgd_t *dst, pgd_t val)
{
	*dst = val;
} 

static inline void pgd_clear (pgd_t * pgd)
{
	set_pgd(pgd, __pgd(0));
}

#define ptep_get_and_clear(mm,addr,xp)	__pte(xchg(&(xp)->pte, 0))

struct mm_struct;

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;
}

#define pte_same(a, b)		((a).pte == (b).pte)

#define pte_pgprot(a)	(__pgprot((a).pte & ~PHYSICAL_PAGE_MASK))

#endif /* !__ASSEMBLY__ */

#define PMD_SIZE	(_AC(1,UL) << PMD_SHIFT)
#define PMD_MASK	(~(PMD_SIZE-1))
#define PUD_SIZE	(_AC(1,UL) << PUD_SHIFT)
#define PUD_MASK	(~(PUD_SIZE-1))
#define PGDIR_SIZE	(_AC(1,UL) << PGDIR_SHIFT)
#define PGDIR_MASK	(~(PGDIR_SIZE-1))


#define MAXMEM		 _AC(0x3fffffffffff, UL)
#define VMALLOC_START    _AC(0xffffc20000000000, UL)
#define VMALLOC_END      _AC(0xffffe1ffffffffff, UL)
#define VMEMMAP_START	 _AC(0xffffe20000000000, UL)
#define MODULES_VADDR    _AC(0xffffffff88000000, UL)
#define MODULES_END      _AC(0xfffffffffff00000, UL)
#define MODULES_LEN   (MODULES_END - MODULES_VADDR)

#ifndef __ASSEMBLY__

static inline unsigned long pgd_bad(pgd_t pgd)
{
	return pgd_val(pgd) & ~(PTE_MASK | _KERNPG_TABLE | _PAGE_USER);
}

static inline unsigned long pud_bad(pud_t pud)
{
	return pud_val(pud) & ~(PTE_MASK | _KERNPG_TABLE | _PAGE_USER);
}

static inline unsigned long pmd_bad(pmd_t pmd)
{
	return pmd_val(pmd) & ~(PTE_MASK | _KERNPG_TABLE | _PAGE_USER);
}

#define pte_none(x)	(!pte_val(x))
#define pte_present(x)	(pte_val(x) & (_PAGE_PRESENT | _PAGE_PROTNONE))
#define pte_clear(mm,addr,xp)	do { set_pte_at(mm, addr, xp, __pte(0)); } while (0)

#define pages_to_mb(x) ((x) >> (20-PAGE_SHIFT))	/* FIXME: is this right? */
#define pte_page(x)	pfn_to_page(pte_pfn(x))
#define pte_pfn(x)  ((pte_val(x) & __PHYSICAL_MASK) >> PAGE_SHIFT)

struct vm_area_struct;

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);
}

static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
{
	clear_bit(_PAGE_BIT_RW, &ptep->pte);
}

/*
 * Macro to mark a page protection value as "uncacheable".
 */
#define pgprot_noncached(prot)	(__pgprot(pgprot_val(prot) | _PAGE_PCD | _PAGE_PWT))


/*
 * Conversion functions: convert a page and protection to a page entry,
 * and a page entry and page directory to the page they refer to.
 */

/*
 * Level 4 access.
 */
#define pgd_page_vaddr(pgd) ((unsigned long) __va((unsigned long)pgd_val(pgd) & PTE_MASK))
#define pgd_page(pgd)		(pfn_to_page(pgd_val(pgd) >> PAGE_SHIFT))
#define pgd_index(address) (((address) >> PGDIR_SHIFT) & (PTRS_PER_PGD-1))
#define pgd_offset(mm, addr) ((mm)->pgd + pgd_index(addr))
#define pgd_offset_k(address) (init_level4_pgt + pgd_index(address))
#define pgd_present(pgd) (pgd_val(pgd) & _PAGE_PRESENT)
#define mk_kernel_pgd(address) ((pgd_t){ (address) | _KERNPG_TABLE })

/* PUD - Level3 access */
/* to find an entry in a page-table-directory. */
#define pud_page_vaddr(pud) ((unsigned long) __va(pud_val(pud) & PHYSICAL_PAGE_MASK))
#define pud_page(pud)		(pfn_to_page(pud_val(pud) >> PAGE_SHIFT))
#define pud_index(address) (((address) >> PUD_SHIFT) & (PTRS_PER_PUD-1))
#define pud_offset(pgd, address) ((pud_t *) pgd_page_vaddr(*(pgd)) + pud_index(address))
#define pud_present(pud) (pud_val(pud) & _PAGE_PRESENT)

/* PMD  - Level 2 access */
#define pmd_page_vaddr(pmd) ((unsigned long) __va(pmd_val(pmd) & PTE_MASK))
#define pmd_page(pmd)		(pfn_to_page(pmd_val(pmd) >> PAGE_SHIFT))

#define pmd_index(address) (((address) >> PMD_SHIFT) & (PTRS_PER_PMD-1))
#define pmd_offset(dir, address) ((pmd_t *) pud_page_vaddr(*(dir)) + \
			pmd_index(address))
#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 pfn_pmd(nr,prot) (__pmd(((nr) << PAGE_SHIFT) | pgprot_val(prot)))
#define pmd_pfn(x)  ((pmd_val(x) & __PHYSICAL_MASK) >> PAGE_SHIFT)

#define pte_to_pgoff(pte) ((pte_val(pte) & PHYSICAL_PAGE_MASK) >> PAGE_SHIFT)
#define pgoff_to_pte(off) ((pte_t) { .pte = ((off) << PAGE_SHIFT) | _PAGE_FILE })
#define PTE_FILE_MAX_BITS __PHYSICAL_MASK_SHIFT

/* PTE - Level 1 access. */

/* page, protection -> pte */
#define mk_pte(page, pgprot)	pfn_pte(page_to_pfn(page), (pgprot))
 
#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))

/* x86-64 always has all page tables mapped. */
#define pte_offset_map(dir,address) pte_offset_kernel(dir,address)
#define pte_offset_map_nested(dir,address) pte_offset_kernel(dir,address)
#define pte_unmap(pte) /* NOP */
#define pte_unmap_nested(pte) /* NOP */ 

#define update_mmu_cache(vma,address,pte) do { } while (0)

/* 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  __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
#define ptep_set_access_flags(__vma, __address, __ptep, __entry, __dirty) \
({									  \
	int __changed = !pte_same(*(__ptep), __entry);			  \
	if (__changed && __dirty) {					  \
		set_pte(__ptep, __entry);			  	  \
		flush_tlb_page(__vma, __address);		  	  \
	}								  \
	__changed;							  \
})

/* Encode and de-code a swap entry */
#define __swp_type(x)			(((x).val >> 1) & 0x3f)
#define __swp_offset(x)			((x).val >> 8)
#define __swp_entry(type, offset)	((swp_entry_t) { ((type) << 1) | ((offset) << 8) })
#define __pte_to_swp_entry(pte)		((swp_entry_t) { pte_val(pte) })
#define __swp_entry_to_pte(x)		((pte_t) { .pte = (x).val })

extern spinlock_t pgd_lock;
extern struct list_head pgd_list;

extern int kern_addr_valid(unsigned long addr); 

pte_t *lookup_address(unsigned long addr);

#define io_remap_pfn_range(vma, vaddr, pfn, size, prot)		\
		remap_pfn_range(vma, vaddr, pfn, size, prot)

#define HAVE_ARCH_UNMAPPED_AREA
#define HAVE_ARCH_UNMAPPED_AREA_TOPDOWN

#define pgtable_cache_init()   do { } while (0)
#define check_pgt_cache()      do { } while (0)

#define PAGE_AGP    PAGE_KERNEL_NOCACHE
#define HAVE_PAGE_AGP 1

/* fs/proc/kcore.c */
#define	kc_vaddr_to_offset(v) ((v) & __VIRTUAL_MASK)
#define	kc_offset_to_vaddr(o) \
   (((o) & (1UL << (__VIRTUAL_MASK_SHIFT-1))) ? ((o) | (~__VIRTUAL_MASK)) : (o))

#define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
#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 /* !__ASSEMBLY__ */

#endif /* _X86_64_PGTABLE_H */