/*
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * Copyright (C) 1994, 95, 96, 97, 98, 99, 2000 by Ralf Baechle at alii
 * Copyright (C) 1999 Silicon Graphics, Inc.
 */
#ifndef _ASM_PGTABLE_H
#define _ASM_PGTABLE_H

#include <linux/config.h>
#include <asm/addrspace.h>
#include <asm/page.h>

#ifndef _LANGUAGE_ASSEMBLY

#include <linux/linkage.h>
#include <asm/cachectl.h>
#include <asm/cacheflush.h>
#include <asm/fixmap.h>
#include <asm/types.h>

/*
 * This flag is used to indicate that the page pointed to by a pte
 * is dirty and requires cleaning before returning it to the user.
 */
#define PG_dcache_dirty			PG_arch_1

#define Page_dcache_dirty(page)		\
	test_bit(PG_dcache_dirty, &(page)->flags)
#define SetPageDcacheDirty(page)	\
	set_bit(PG_dcache_dirty, &(page)->flags)
#define ClearPageDcacheDirty(page)	\
	clear_bit(PG_dcache_dirty, &(page)->flags)

/*
 * - add_wired_entry() add a fixed TLB entry, and move wired register
 */
extern void add_wired_entry(unsigned long entrylo0, unsigned long entrylo1,
			       unsigned long entryhi, unsigned long pagemask);

/*
 * - add_temporary_entry() add a temporary TLB entry. We use TLB entries
 *	starting at the top and working down. This is for populating the
 *	TLB before trap_init() puts the TLB miss handler in place. It
 *	should be used only for entries matching the actual page tables,
 *	to prevent inconsistencies.
 */
extern int add_temporary_entry(unsigned long entrylo0, unsigned long entrylo1,
			       unsigned long entryhi, unsigned long pagemask);


/* Basically we have the same two-level (which is the logical three level
 * Linux page table layout folded) page tables as the i386.  Some day
 * when we have proper page coloring support we can have a 1% quicker
 * tlb refill handling mechanism, but for now it is a bit slower but
 * works even with the cache aliasing problem the R4k and above have.
 */

/* PMD_SHIFT determines the size of the area a second-level page table can map */

#ifdef CONFIG_64BIT_PHYS_ADDR
extern int remap_page_range_high(unsigned long from, phys_t to, unsigned long size, pgprot_t prot);
#endif
#endif /* !defined (_LANGUAGE_ASSEMBLY) */

#define PMD_SIZE	(1UL << PMD_SHIFT)
#define PMD_MASK	(~(PMD_SIZE-1))

/* PGDIR_SHIFT determines what a third-level page table entry can map */
#define PGDIR_SHIFT	PMD_SHIFT
#define PGDIR_SIZE	(1UL << PGDIR_SHIFT)
#define PGDIR_MASK	(~(PGDIR_SIZE-1))

#define USER_PTRS_PER_PGD	(0x80000000UL/PGDIR_SIZE)
#define FIRST_USER_PGD_NR	0

#define VMALLOC_START     KSEG2
#define VMALLOC_VMADDR(x) ((unsigned long)(x))

#if CONFIG_HIGHMEM
# define VMALLOC_END	(PKMAP_BASE-2*PAGE_SIZE)
#else
# define VMALLOC_END	(FIXADDR_START-2*PAGE_SIZE)
#endif

#include <asm/pgtable-bits.h>

#define PAGE_NONE	__pgprot(_PAGE_PRESENT | _CACHE_CACHABLE_NONCOHERENT)
#define PAGE_SHARED     __pgprot(_PAGE_PRESENT | _PAGE_READ | _PAGE_WRITE | \
			PAGE_CACHABLE_DEFAULT)
#define PAGE_COPY       __pgprot(_PAGE_PRESENT | _PAGE_READ | \
			PAGE_CACHABLE_DEFAULT)
#define PAGE_READONLY   __pgprot(_PAGE_PRESENT | _PAGE_READ | \
			PAGE_CACHABLE_DEFAULT)
#define PAGE_KERNEL	__pgprot(_PAGE_PRESENT | __READABLE | __WRITEABLE | \
			_PAGE_GLOBAL | PAGE_CACHABLE_DEFAULT)
#define PAGE_USERIO     __pgprot(_PAGE_PRESENT | _PAGE_READ | _PAGE_WRITE | \
			PAGE_CACHABLE_DEFAULT)
#define PAGE_KERNEL_UNCACHED __pgprot(_PAGE_PRESENT | __READABLE | \
			__WRITEABLE | _PAGE_GLOBAL | _CACHE_UNCACHED)

/*
 * MIPS can't do page protection for execute, and considers that the same like
 * read. Also, write permissions imply read permissions. This is the closest
 * we can get by reasonable means..
 */
#define __P000	PAGE_NONE
#define __P001	PAGE_READONLY
#define __P010	PAGE_COPY
#define __P011	PAGE_COPY
#define __P100	PAGE_READONLY
#define __P101	PAGE_READONLY
#define __P110	PAGE_COPY
#define __P111	PAGE_COPY

#define __S000	PAGE_NONE
#define __S001	PAGE_READONLY
#define __S010	PAGE_SHARED
#define __S011	PAGE_SHARED
#define __S100	PAGE_READONLY
#define __S101	PAGE_READONLY
#define __S110	PAGE_SHARED
#define __S111	PAGE_SHARED

#if defined(CONFIG_64BIT_PHYS_ADDR) && defined(CONFIG_CPU_MIPS32)
#include <asm/pgtable-64.h>
#else
#include <asm/pgtable-32.h>
#endif

#if !defined (_LANGUAGE_ASSEMBLY)

extern unsigned long empty_zero_page;
extern unsigned long zero_page_mask;

#define ZERO_PAGE(vaddr) \
	(virt_to_page(empty_zero_page + (((unsigned long)(vaddr)) & zero_page_mask)))

extern void load_pgd(unsigned long pg_dir);

extern pmd_t invalid_pte_table[PAGE_SIZE/sizeof(pmd_t)];

/*
 * Conversion functions: convert a page and protection to a page entry,
 * and a page entry and page directory to the page they refer to.
 */
static inline unsigned long pmd_page(pmd_t pmd)
{
	return pmd_val(pmd);
}

static inline void pmd_set(pmd_t * pmdp, pte_t * ptep)
{
	pmd_val(*pmdp) = (((unsigned long) ptep) & PAGE_MASK);
}

static inline int pte_present(pte_t pte) { return pte_val(pte) & _PAGE_PRESENT; }

/*
 * (pmds are folded into pgds so this doesn't get actually called,
 * but the define is needed for a generic inline function.)
 */
#define set_pmd(pmdptr, pmdval) (*(pmdptr) = pmdval)
#define set_pgd(pgdptr, pgdval) (*(pgdptr) = pgdval)

/*
 * Empty pgd/pmd entries point to the invalid_pte_table.
 */
static inline int pmd_none(pmd_t pmd)
{
	return pmd_val(pmd) == (unsigned long) invalid_pte_table;
}

static inline int pmd_bad(pmd_t pmd)
{
	return ((pmd_page(pmd) > (unsigned long) high_memory) ||
	        (pmd_page(pmd) < PAGE_OFFSET));
}

static inline int pmd_present(pmd_t pmd)
{
	return (pmd_val(pmd) != (unsigned long) invalid_pte_table);
}

static inline void pmd_clear(pmd_t *pmdp)
{
	pmd_val(*pmdp) = ((unsigned long) invalid_pte_table);
}

/*
 * The "pgd_xxx()" functions here are trivial for a folded two-level
 * setup: the pgd is never bad, and a pmd always exists (as it's folded
 * into the pgd entry)
 */
static inline int pgd_none(pgd_t pgd)		{ return 0; }
static inline int pgd_bad(pgd_t pgd)		{ return 0; }
static inline int pgd_present(pgd_t pgd)	{ return 1; }
static inline void pgd_clear(pgd_t *pgdp)	{ }

/*
 * The following only work if pte_present() is true.
 * Undefined behaviour if not..
 */

static inline int pte_read(pte_t pte)	{ return (pte).pte_low & _PAGE_READ; }
static inline int pte_write(pte_t pte)	{ return (pte).pte_low & _PAGE_WRITE; }
static inline int pte_dirty(pte_t pte)	{ return (pte).pte_low & _PAGE_MODIFIED; }
static inline int pte_young(pte_t pte)	{ return (pte).pte_low & _PAGE_ACCESSED; }

/*
 * (pmds are folded into pgds so this doesnt get actually called,
 * but the define is needed for a generic inline function.)
 */
#define set_pmd(pmdptr, pmdval) (*(pmdptr) = pmdval)
#define set_pgd(pgdptr, pgdval) (*(pgdptr) = pgdval)

#define PGD_T_LOG2	ffz(~sizeof(pgd_t))
#define PMD_T_LOG2	ffz(~sizeof(pmd_t))
#define PTE_T_LOG2	ffz(~sizeof(pte_t))

#define PTRS_PER_PGD	((PAGE_SIZE << PGD_ORDER) / sizeof(pgd_t))
#define PTRS_PER_PMD	1
#define PTRS_PER_PTE	((PAGE_SIZE << PTE_ORDER) / sizeof(pte_t))

#define page_pte(page) page_pte_prot(page, __pgprot(0))

#define __pgd_offset(address)	pgd_index(address)
#define __pmd_offset(address) \
	(((address) >> PMD_SHIFT) & (PTRS_PER_PMD-1))

/* to find an entry in a kernel page-table-directory */
#define pgd_offset_k(address) pgd_offset(&init_mm, address)

#define pgd_index(address)	((address) >> PGDIR_SHIFT)

/* to find an entry in a page-table-directory */
static inline pgd_t *pgd_offset(struct mm_struct *mm, unsigned long address)
{
	return mm->pgd + pgd_index(address);
}

/* Find an entry in the second-level page table.. */
static inline pmd_t *pmd_offset(pgd_t *dir, unsigned long address)
{
	return (pmd_t *) dir;
}

/* Find an entry in the third-level page table.. */
static inline pte_t *pte_offset(pmd_t * dir, unsigned long address)
{
	return (pte_t *) (pmd_page(*dir)) +
	       ((address >> PAGE_SHIFT) & (PTRS_PER_PTE - 1));
}

extern int do_check_pgt_cache(int, int);

extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
extern void paging_init(void);

extern void __update_tlb(struct vm_area_struct *vma, unsigned long address,
	pte_t pte);
extern void __update_cache(struct vm_area_struct *vma, unsigned long address,
	pte_t pte);

static inline void update_mmu_cache(struct vm_area_struct *vma,
	unsigned long address, pte_t pte)
{
	__update_tlb(vma, address, pte);
	__update_cache(vma, address, pte);
}

/* Swap entries must have VALID and GLOBAL bits cleared. */
#if defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_TX39XX)

#define SWP_TYPE(x)		(((x).val >> 1) & 0x7f)
#define SWP_OFFSET(x)		((x).val >> 10)
#define SWP_ENTRY(type,offset)	((swp_entry_t) { ((type) << 1) | ((offset) << 10) })
#else

#define SWP_TYPE(x)		(((x).val >> 1) & 0x1f)
#define SWP_OFFSET(x)		((x).val >> 8)
#define SWP_ENTRY(type,offset)	((swp_entry_t) { ((type) << 1) | ((offset) << 8) })
#endif

#define pte_to_swp_entry(pte)	((swp_entry_t) { (pte).pte_low })
#define swp_entry_to_pte(x)	((pte_t) { (x).val })


/* Needs to be defined here and not in linux/mm.h, as it is arch dependent */
#define PageSkip(page)		(0)
#define kern_addr_valid(addr)	(1)

#include <asm-generic/pgtable.h>

#endif /* !defined (_LANGUAGE_ASSEMBLY) */

/*
 * We provide our own get_unmapped area to cope with the virtual aliasing
 * constraints placed on us by the cache architecture.
 */
#define HAVE_ARCH_UNMAPPED_AREA

#ifdef CONFIG_64BIT_PHYS_ADDR
#define io_remap_page_range remap_page_range_high
#else
#define io_remap_page_range remap_page_range
#endif

/*
 * No page table caches to initialise
 */
#define pgtable_cache_init()	do { } while (0)

#endif /* _ASM_PGTABLE_H */