[deliverable/linux.git] / include / asm-ppc64 / pgtable.h

#ifndef _PPC64_PGTABLE_H
#define _PPC64_PGTABLE_H

/*
 * This file contains the functions and defines necessary to modify and use
 * the ppc64 hashed page table.
 */

#ifndef __ASSEMBLY__
#include <linux/config.h>
#include <linux/stddef.h>
#include <asm/processor.h>		/* For TASK_SIZE */
#include <asm/mmu.h>
#include <asm/page.h>
#include <asm/tlbflush.h>
#endif /* __ASSEMBLY__ */

#include <asm-generic/pgtable-nopud.h>

/*
 * Entries per page directory level.  The PTE level must use a 64b record
 * for each page table entry.  The PMD and PGD level use a 32b record for 
 * each entry by assuming that each entry is page aligned.
 */
#define PTE_INDEX_SIZE  9
#define PMD_INDEX_SIZE  10
#define PGD_INDEX_SIZE  10

#define PTRS_PER_PTE	(1 << PTE_INDEX_SIZE)
#define PTRS_PER_PMD	(1 << PMD_INDEX_SIZE)
#define PTRS_PER_PGD	(1 << PGD_INDEX_SIZE)

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

#define FIRST_USER_ADDRESS	0

/*
 * Size of EA range mapped by our pagetables.
 */
#define EADDR_SIZE (PTE_INDEX_SIZE + PMD_INDEX_SIZE + \
                    PGD_INDEX_SIZE + PAGE_SHIFT)
#define EADDR_MASK ((1UL << EADDR_SIZE) - 1)

/*
 * Define the address range of the vmalloc VM area.
 */
#define VMALLOC_START (0xD000000000000000ul)
#define VMALLOC_END   (VMALLOC_START + EADDR_MASK)

/*
 * Bits in a linux-style PTE.  These match the bits in the
 * (hardware-defined) PowerPC PTE as closely as possible.
 */
#define _PAGE_PRESENT	0x0001 /* software: pte contains a translation */
#define _PAGE_USER	0x0002 /* matches one of the PP bits */
#define _PAGE_FILE	0x0002 /* (!present only) software: pte holds file offset */
#define _PAGE_EXEC	0x0004 /* No execute on POWER4 and newer (we invert) */
#define _PAGE_GUARDED	0x0008
#define _PAGE_COHERENT	0x0010 /* M: enforce memory coherence (SMP systems) */
#define _PAGE_NO_CACHE	0x0020 /* I: cache inhibit */
#define _PAGE_WRITETHRU	0x0040 /* W: cache write-through */
#define _PAGE_DIRTY	0x0080 /* C: page changed */
#define _PAGE_ACCESSED	0x0100 /* R: page referenced */
#define _PAGE_RW	0x0200 /* software: user write access allowed */
#define _PAGE_HASHPTE	0x0400 /* software: pte has an associated HPTE */
#define _PAGE_BUSY	0x0800 /* software: PTE & hash are busy */ 
#define _PAGE_SECONDARY 0x8000 /* software: HPTE is in secondary group */
#define _PAGE_GROUP_IX  0x7000 /* software: HPTE index within group */
#define _PAGE_HUGE	0x10000 /* 16MB page */
/* Bits 0x7000 identify the index within an HPT Group */
#define _PAGE_HPTEFLAGS (_PAGE_BUSY | _PAGE_HASHPTE | _PAGE_SECONDARY | _PAGE_GROUP_IX)
/* PAGE_MASK gives the right answer below, but only by accident */
/* It should be preserving the high 48 bits and then specifically */
/* preserving _PAGE_SECONDARY | _PAGE_GROUP_IX */
#define _PAGE_CHG_MASK	(PAGE_MASK | _PAGE_ACCESSED | _PAGE_DIRTY | _PAGE_HPTEFLAGS)

#define _PAGE_BASE	(_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_COHERENT)

#define _PAGE_WRENABLE	(_PAGE_RW | _PAGE_DIRTY)

/* __pgprot defined in asm-ppc64/page.h */
#define PAGE_NONE	__pgprot(_PAGE_PRESENT | _PAGE_ACCESSED)

#define PAGE_SHARED	__pgprot(_PAGE_BASE | _PAGE_RW | _PAGE_USER)
#define PAGE_SHARED_X	__pgprot(_PAGE_BASE | _PAGE_RW | _PAGE_USER | _PAGE_EXEC)
#define PAGE_COPY	__pgprot(_PAGE_BASE | _PAGE_USER)
#define PAGE_COPY_X	__pgprot(_PAGE_BASE | _PAGE_USER | _PAGE_EXEC)
#define PAGE_READONLY	__pgprot(_PAGE_BASE | _PAGE_USER)
#define PAGE_READONLY_X	__pgprot(_PAGE_BASE | _PAGE_USER | _PAGE_EXEC)
#define PAGE_KERNEL	__pgprot(_PAGE_BASE | _PAGE_WRENABLE)
#define PAGE_KERNEL_CI	__pgprot(_PAGE_PRESENT | _PAGE_ACCESSED | \
			       _PAGE_WRENABLE | _PAGE_NO_CACHE | _PAGE_GUARDED)
#define PAGE_KERNEL_EXEC __pgprot(_PAGE_BASE | _PAGE_WRENABLE | _PAGE_EXEC)

#define PAGE_AGP	__pgprot(_PAGE_BASE | _PAGE_WRENABLE | _PAGE_NO_CACHE)
#define HAVE_PAGE_AGP

/*
 * This bit in a hardware PTE indicates that the page is *not* executable.
 */
#define HW_NO_EXEC	_PAGE_EXEC

/*
 * POWER4 and newer have per page execute protection, older chips can only
 * do this on a segment (256MB) basis.
 *
 * Also, write permissions imply read permissions.
 * This is the closest we can get..
 *
 * Note due to the way vm flags are laid out, the bits are XWR
 */
#define __P000	PAGE_NONE
#define __P001	PAGE_READONLY
#define __P010	PAGE_COPY
#define __P011	PAGE_COPY
#define __P100	PAGE_READONLY_X
#define __P101	PAGE_READONLY_X
#define __P110	PAGE_COPY_X
#define __P111	PAGE_COPY_X

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

#ifndef __ASSEMBLY__

/*
 * 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__ */

/* shift to put page number into pte */
#define PTE_SHIFT (17)

#ifdef CONFIG_HUGETLB_PAGE

#ifndef __ASSEMBLY__
int hash_huge_page(struct mm_struct *mm, unsigned long access,
		   unsigned long ea, unsigned long vsid, int local);

void hugetlb_mm_free_pgd(struct mm_struct *mm);
#endif /* __ASSEMBLY__ */

#define HAVE_ARCH_UNMAPPED_AREA
#define HAVE_ARCH_UNMAPPED_AREA_TOPDOWN
#else

#define hash_huge_page(mm,a,ea,vsid,local)	-1
#define hugetlb_mm_free_pgd(mm)			do {} while (0)

#endif

#ifndef __ASSEMBLY__

/*
 * Conversion functions: convert a page and protection to a page entry,
 * and a page entry and page directory to the page they refer to.
 *
 * mk_pte takes a (struct page *) as input
 */
#define mk_pte(page, pgprot)	pfn_pte(page_to_pfn(page), (pgprot))

static inline pte_t pfn_pte(unsigned long pfn, pgprot_t pgprot)
{
	pte_t pte;


	pte_val(pte) = (pfn << PTE_SHIFT) | pgprot_val(pgprot);
	return pte;
}

#define pte_modify(_pte, newprot) \
  (__pte((pte_val(_pte) & _PAGE_CHG_MASK) | pgprot_val(newprot)))

#define pte_none(pte)		((pte_val(pte) & ~_PAGE_HPTEFLAGS) == 0)
#define pte_present(pte)	(pte_val(pte) & _PAGE_PRESENT)

/* pte_clear moved to later in this file */

#define pte_pfn(x)		((unsigned long)((pte_val(x) >> PTE_SHIFT)))
#define pte_page(x)		pfn_to_page(pte_pfn(x))

#define pmd_set(pmdp, ptep) 	\
	(pmd_val(*(pmdp)) = __ba_to_bpn(ptep))
#define pmd_none(pmd)		(!pmd_val(pmd))
#define	pmd_bad(pmd)		(pmd_val(pmd) == 0)
#define	pmd_present(pmd)	(pmd_val(pmd) != 0)
#define	pmd_clear(pmdp)		(pmd_val(*(pmdp)) = 0)
#define pmd_page_kernel(pmd)	(__bpn_to_ba(pmd_val(pmd)))
#define pmd_page(pmd)		virt_to_page(pmd_page_kernel(pmd))

#define pud_set(pudp, pmdp)	(pud_val(*(pudp)) = (__ba_to_bpn(pmdp)))
#define pud_none(pud)		(!pud_val(pud))
#define pud_bad(pud)		((pud_val(pud)) == 0UL)
#define pud_present(pud)	(pud_val(pud) != 0UL)
#define pud_clear(pudp)		(pud_val(*(pudp)) = 0UL)
#define pud_page(pud)		(__bpn_to_ba(pud_val(pud)))

/* 
 * Find an entry in a page-table-directory.  We combine the address region 
 * (the high order N bits) and the pgd portion of the address.
 */
/* to avoid overflow in free_pgtables we don't use PTRS_PER_PGD here */
#define pgd_index(address) (((address) >> (PGDIR_SHIFT)) & 0x7ff)

#define pgd_offset(mm, address)	 ((mm)->pgd + pgd_index(address))

/* Find an entry in the second-level page table.. */
#define pmd_offset(pudp,addr) \
  ((pmd_t *) pud_page(*(pudp)) + (((addr) >> PMD_SHIFT) & (PTRS_PER_PMD - 1)))

/* Find an entry in the third-level page table.. */
#define pte_offset_kernel(dir,addr) \
  ((pte_t *) pmd_page_kernel(*(dir)) \
 + (((addr) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1)))

#define pte_offset_map(dir,addr)	pte_offset_kernel((dir), (addr))
#define pte_offset_map_nested(dir,addr)	pte_offset_kernel((dir), (addr))
#define pte_unmap(pte)			do { } while(0)
#define pte_unmap_nested(pte)		do { } while(0)

/* to find an entry in a kernel page-table-directory */
/* This now only contains the vmalloc pages */
#define pgd_offset_k(address) pgd_offset(&init_mm, address)

/* to find an entry in the ioremap page-table-directory */
#define pgd_offset_i(address) (ioremap_pgd + pgd_index(address))

/*
 * The following only work if pte_present() is true.
 * Undefined behaviour if not..
 */
static inline int pte_read(pte_t pte)  { return pte_val(pte) & _PAGE_USER;}
static inline int pte_write(pte_t pte) { return pte_val(pte) & _PAGE_RW;}
static inline int pte_exec(pte_t pte)  { return pte_val(pte) & _PAGE_EXEC;}
static inline int pte_dirty(pte_t pte) { return pte_val(pte) & _PAGE_DIRTY;}
static inline int pte_young(pte_t pte) { return pte_val(pte) & _PAGE_ACCESSED;}
static inline int pte_file(pte_t pte) { return pte_val(pte) & _PAGE_FILE;}
static inline int pte_huge(pte_t pte) { return pte_val(pte) & _PAGE_HUGE;}

static inline void pte_uncache(pte_t pte) { pte_val(pte) |= _PAGE_NO_CACHE; }
static inline void pte_cache(pte_t pte)   { pte_val(pte) &= ~_PAGE_NO_CACHE; }

static inline pte_t pte_rdprotect(pte_t pte) {
	pte_val(pte) &= ~_PAGE_USER; return pte; }
static inline pte_t pte_exprotect(pte_t pte) {
	pte_val(pte) &= ~_PAGE_EXEC; return pte; }
static inline pte_t pte_wrprotect(pte_t pte) {
	pte_val(pte) &= ~(_PAGE_RW); return pte; }
static inline pte_t pte_mkclean(pte_t pte) {
	pte_val(pte) &= ~(_PAGE_DIRTY); return pte; }
static inline pte_t pte_mkold(pte_t pte) {
	pte_val(pte) &= ~_PAGE_ACCESSED; return pte; }

static inline pte_t pte_mkread(pte_t pte) {
	pte_val(pte) |= _PAGE_USER; return pte; }
static inline pte_t pte_mkexec(pte_t pte) {
	pte_val(pte) |= _PAGE_USER | _PAGE_EXEC; return pte; }
static inline pte_t pte_mkwrite(pte_t pte) {
	pte_val(pte) |= _PAGE_RW; return pte; }
static inline pte_t pte_mkdirty(pte_t pte) {
	pte_val(pte) |= _PAGE_DIRTY; return pte; }
static inline pte_t pte_mkyoung(pte_t pte) {
	pte_val(pte) |= _PAGE_ACCESSED; return pte; }
static inline pte_t pte_mkhuge(pte_t pte) {
	pte_val(pte) |= _PAGE_HUGE; return pte; }

/* Atomic PTE updates */
static inline unsigned long pte_update(pte_t *p, unsigned long clr)
{
	unsigned long old, tmp;

	__asm__ __volatile__(
	"1:	ldarx	%0,0,%3		# pte_update\n\
	andi.	%1,%0,%6\n\
	bne-	1b \n\
	andc	%1,%0,%4 \n\
	stdcx.	%1,0,%3 \n\
	bne-	1b"
	: "=&r" (old), "=&r" (tmp), "=m" (*p)
	: "r" (p), "r" (clr), "m" (*p), "i" (_PAGE_BUSY)
	: "cc" );
	return old;
}

/* PTE updating functions, this function puts the PTE in the
 * batch, doesn't actually triggers the hash flush immediately,
 * you need to call flush_tlb_pending() to do that.
 */
extern void hpte_update(struct mm_struct *mm, unsigned long addr, unsigned long pte,
			int wrprot);

static inline int __ptep_test_and_clear_young(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
{
	unsigned long old;

       	if ((pte_val(*ptep) & (_PAGE_ACCESSED | _PAGE_HASHPTE)) == 0)
		return 0;
	old = pte_update(ptep, _PAGE_ACCESSED);
	if (old & _PAGE_HASHPTE) {
		hpte_update(mm, addr, old, 0);
		flush_tlb_pending();
	}
	return (old & _PAGE_ACCESSED) != 0;
}
#define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
#define ptep_test_and_clear_young(__vma, __addr, __ptep)		   \
({									   \
	int __r;							   \
	__r = __ptep_test_and_clear_young((__vma)->vm_mm, __addr, __ptep); \
	__r;								   \
})

/*
 * On RW/DIRTY bit transitions we can avoid flushing the hpte. For the
 * moment we always flush but we need to fix hpte_update and test if the
 * optimisation is worth it.
 */
static inline int __ptep_test_and_clear_dirty(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
{
	unsigned long old;

       	if ((pte_val(*ptep) & _PAGE_DIRTY) == 0)
		return 0;
	old = pte_update(ptep, _PAGE_DIRTY);
	if (old & _PAGE_HASHPTE)
		hpte_update(mm, addr, old, 0);
	return (old & _PAGE_DIRTY) != 0;
}
#define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_DIRTY
#define ptep_test_and_clear_dirty(__vma, __addr, __ptep)		   \
({									   \
	int __r;							   \
	__r = __ptep_test_and_clear_dirty((__vma)->vm_mm, __addr, __ptep); \
	__r;								   \
})

#define __HAVE_ARCH_PTEP_SET_WRPROTECT
static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
{
	unsigned long old;

       	if ((pte_val(*ptep) & _PAGE_RW) == 0)
       		return;
	old = pte_update(ptep, _PAGE_RW);
	if (old & _PAGE_HASHPTE)
		hpte_update(mm, addr, old, 0);
}

/*
 * We currently remove entries from the hashtable regardless of whether
 * the entry was young or dirty. The generic routines only flush if the
 * entry was young or dirty which is not good enough.
 *
 * We should be more intelligent about this but for the moment we override
 * these functions and force a tlb flush unconditionally
 */
#define __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSH
#define ptep_clear_flush_young(__vma, __address, __ptep)		\
({									\
	int __young = __ptep_test_and_clear_young((__vma)->vm_mm, __address, \
						  __ptep);		\
	__young;							\
})

#define __HAVE_ARCH_PTEP_CLEAR_DIRTY_FLUSH
#define ptep_clear_flush_dirty(__vma, __address, __ptep)		\
({									\
	int __dirty = __ptep_test_and_clear_dirty((__vma)->vm_mm, __address, \
						  __ptep); 		\
	flush_tlb_page(__vma, __address);				\
	__dirty;							\
})

#define __HAVE_ARCH_PTEP_GET_AND_CLEAR
static inline pte_t ptep_get_and_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
{
	unsigned long old = pte_update(ptep, ~0UL);

	if (old & _PAGE_HASHPTE)
		hpte_update(mm, addr, old, 0);
	return __pte(old);
}

static inline void pte_clear(struct mm_struct *mm, unsigned long addr, pte_t * ptep)
{
	unsigned long old = pte_update(ptep, ~0UL);

	if (old & _PAGE_HASHPTE)
		hpte_update(mm, addr, old, 0);
}

/*
 * set_pte stores a linux PTE into the linux page table.
 */
static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
			      pte_t *ptep, pte_t pte)
{
	if (pte_present(*ptep)) {
		pte_clear(mm, addr, ptep);
		flush_tlb_pending();
	}
	*ptep = __pte(pte_val(pte) & ~_PAGE_HPTEFLAGS);
}

/* Set the dirty and/or accessed bits atomically in a linux PTE, this
 * function doesn't need to flush the hash entry
 */
#define __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
static inline void __ptep_set_access_flags(pte_t *ptep, pte_t entry, int dirty)
{
	unsigned long bits = pte_val(entry) &
		(_PAGE_DIRTY | _PAGE_ACCESSED | _PAGE_RW | _PAGE_EXEC);
	unsigned long old, tmp;

	__asm__ __volatile__(
	"1:	ldarx	%0,0,%4\n\
		andi.	%1,%0,%6\n\
		bne-	1b \n\
		or	%0,%3,%0\n\
		stdcx.	%0,0,%4\n\
		bne-	1b"
	:"=&r" (old), "=&r" (tmp), "=m" (*ptep)
	:"r" (bits), "r" (ptep), "m" (*ptep), "i" (_PAGE_BUSY)
	:"cc");
}
#define  ptep_set_access_flags(__vma, __address, __ptep, __entry, __dirty) \
	do {								   \
		__ptep_set_access_flags(__ptep, __entry, __dirty);	   \
		flush_tlb_page_nohash(__vma, __address);	       	   \
	} while(0)

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

struct file;
extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long addr,
				     unsigned long size, pgprot_t vma_prot);
#define __HAVE_PHYS_MEM_ACCESS_PROT

#define __HAVE_ARCH_PTE_SAME
#define pte_same(A,B)	(((pte_val(A) ^ pte_val(B)) & ~_PAGE_HPTEFLAGS) == 0)

extern unsigned long ioremap_bot, ioremap_base;

#define pmd_ERROR(e) \
	printk("%s:%d: bad pmd %08x.\n", __FILE__, __LINE__, pmd_val(e))
#define pgd_ERROR(e) \
	printk("%s:%d: bad pgd %08x.\n", __FILE__, __LINE__, pgd_val(e))

extern pgd_t swapper_pg_dir[];
extern pgd_t ioremap_dir[];

extern void paging_init(void);

/*
 * Because the huge pgtables are only 2 level, they can take
 * at most around 4M, much less than one hugepage which the
 * process is presumably entitled to use.  So we don't bother
 * freeing up the pagetables on unmap, and wait until
 * destroy_context() to clean up the lot.
 */
#define hugetlb_free_pgd_range(tlb, addr, end, floor, ceiling) \
						do { } while (0)

/*
 * This gets called at the end of handling a page fault, when
 * the kernel has put a new PTE into the page table for the process.
 * We use it to put a corresponding HPTE into the hash table
 * ahead of time, instead of waiting for the inevitable extra
 * hash-table miss exception.
 */
struct vm_area_struct;
extern void update_mmu_cache(struct vm_area_struct *, unsigned long, pte_t);

/* Encode and de-code a swap entry */
#define __swp_type(entry)	(((entry).val >> 1) & 0x3f)
#define __swp_offset(entry)	((entry).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) >> PTE_SHIFT })
#define __swp_entry_to_pte(x)	((pte_t) { (x).val << PTE_SHIFT })
#define pte_to_pgoff(pte)	(pte_val(pte) >> PTE_SHIFT)
#define pgoff_to_pte(off)	((pte_t) {((off) << PTE_SHIFT)|_PAGE_FILE})
#define PTE_FILE_MAX_BITS	(BITS_PER_LONG - PTE_SHIFT)

/*
 * kern_addr_valid is intended to indicate whether an address is a valid
 * kernel address.  Most 32-bit archs define it as always true (like this)
 * but most 64-bit archs actually perform a test.  What should we do here?
 * The only use is in fs/ncpfs/dir.c
 */
#define kern_addr_valid(addr)	(1)

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

void pgtable_cache_init(void);

/*
 * find_linux_pte returns the address of a linux pte for a given 
 * effective address and directory.  If not found, it returns zero.
 */
static inline pte_t *find_linux_pte(pgd_t *pgdir, unsigned long ea)
{
	pgd_t *pg;
	pud_t *pu;
	pmd_t *pm;
	pte_t *pt = NULL;
	pte_t pte;

	pg = pgdir + pgd_index(ea);
	if (!pgd_none(*pg)) {
		pu = pud_offset(pg, ea);
		if (!pud_none(*pu)) {
			pm = pmd_offset(pu, ea);
			if (pmd_present(*pm)) {
				pt = pte_offset_kernel(pm, ea);
				pte = *pt;
				if (!pte_present(pte))
					pt = NULL;
			}
		}
	}

	return pt;
}

#include <asm-generic/pgtable.h>

#endif /* __ASSEMBLY__ */

#endif /* _PPC64_PGTABLE_H */
Commit	Line	Data
1da177e4 LT	1	#ifndef _PPC64_PGTABLE_H
	2	#define _PPC64_PGTABLE_H
	3
1da177e4 LT	4	/*
	5	* This file contains the functions and defines necessary to modify and use
	6	* the ppc64 hashed page table.
	7	*/
	8
	9	#ifndef __ASSEMBLY__
	10	#include <linux/config.h>
	11	#include <linux/stddef.h>
	12	#include <asm/processor.h> /* For TASK_SIZE */
	13	#include <asm/mmu.h>
	14	#include <asm/page.h>
	15	#include <asm/tlbflush.h>
	16	#endif /* __ASSEMBLY__ */
	17
58366af5 BH	18	#include <asm-generic/pgtable-nopud.h>
58366af5 BH	19
1da177e4 LT	20	/*
	21	* Entries per page directory level. The PTE level must use a 64b record
	22	* for each page table entry. The PMD and PGD level use a 32b record for
	23	* each entry by assuming that each entry is page aligned.
	24	*/
	25	#define PTE_INDEX_SIZE 9
	26	#define PMD_INDEX_SIZE 10
	27	#define PGD_INDEX_SIZE 10
	28
	29	#define PTRS_PER_PTE (1 << PTE_INDEX_SIZE)
	30	#define PTRS_PER_PMD (1 << PMD_INDEX_SIZE)
	31	#define PTRS_PER_PGD (1 << PGD_INDEX_SIZE)
	32
1f8d419e DG	33	/* PMD_SHIFT determines what a second-level page table entry can map */
	34	#define PMD_SHIFT (PAGE_SHIFT + PTE_INDEX_SIZE)
	35	#define PMD_SIZE (1UL << PMD_SHIFT)
	36	#define PMD_MASK (~(PMD_SIZE-1))
1da177e4	37
1f8d419e DG	38	/* PGDIR_SHIFT determines what a third-level page table entry can map */
	39	#define PGDIR_SHIFT (PMD_SHIFT + PMD_INDEX_SIZE)
	40	#define PGDIR_SIZE (1UL << PGDIR_SHIFT)
	41	#define PGDIR_MASK (~(PGDIR_SIZE-1))
	42
	43	#define FIRST_USER_ADDRESS 0
1da177e4 LT	44
	45	/*
	46	* Size of EA range mapped by our pagetables.
	47	*/
1f8d419e DG	48	#define EADDR_SIZE (PTE_INDEX_SIZE + PMD_INDEX_SIZE + \
	49	PGD_INDEX_SIZE + PAGE_SHIFT)
	50	#define EADDR_MASK ((1UL << EADDR_SIZE) - 1)
1da177e4 LT	51
	52	/*
	53	* Define the address range of the vmalloc VM area.
	54	*/
	55	#define VMALLOC_START (0xD000000000000000ul)
1f8d419e	56	#define VMALLOC_END (VMALLOC_START + EADDR_MASK)
1da177e4 LT	57
	58	/*
	59	* Bits in a linux-style PTE. These match the bits in the
	60	* (hardware-defined) PowerPC PTE as closely as possible.
	61	*/
	62	#define _PAGE_PRESENT 0x0001 /* software: pte contains a translation */
	63	#define _PAGE_USER 0x0002 /* matches one of the PP bits */
	64	#define _PAGE_FILE 0x0002 /* (!present only) software: pte holds file offset */
	65	#define _PAGE_EXEC 0x0004 /* No execute on POWER4 and newer (we invert) */
	66	#define _PAGE_GUARDED 0x0008
	67	#define _PAGE_COHERENT 0x0010 /* M: enforce memory coherence (SMP systems) */
	68	#define _PAGE_NO_CACHE 0x0020 /* I: cache inhibit */
	69	#define _PAGE_WRITETHRU 0x0040 /* W: cache write-through */
	70	#define _PAGE_DIRTY 0x0080 /* C: page changed */
	71	#define _PAGE_ACCESSED 0x0100 /* R: page referenced */
	72	#define _PAGE_RW 0x0200 /* software: user write access allowed */
	73	#define _PAGE_HASHPTE 0x0400 /* software: pte has an associated HPTE */
	74	#define _PAGE_BUSY 0x0800 /* software: PTE & hash are busy */
	75	#define _PAGE_SECONDARY 0x8000 /* software: HPTE is in secondary group */
	76	#define _PAGE_GROUP_IX 0x7000 /* software: HPTE index within group */
	77	#define _PAGE_HUGE 0x10000 /* 16MB page */
	78	/* Bits 0x7000 identify the index within an HPT Group */
	79	#define _PAGE_HPTEFLAGS (_PAGE_BUSY \| _PAGE_HASHPTE \| _PAGE_SECONDARY \| _PAGE_GROUP_IX)
	80	/* PAGE_MASK gives the right answer below, but only by accident */
	81	/* It should be preserving the high 48 bits and then specifically */
	82	/* preserving _PAGE_SECONDARY \| _PAGE_GROUP_IX */
	83	#define _PAGE_CHG_MASK (PAGE_MASK \| _PAGE_ACCESSED \| _PAGE_DIRTY \| _PAGE_HPTEFLAGS)
	84
	85	#define _PAGE_BASE (_PAGE_PRESENT \| _PAGE_ACCESSED \| _PAGE_COHERENT)
	86
	87	#define _PAGE_WRENABLE (_PAGE_RW \| _PAGE_DIRTY)
	88
	89	/* __pgprot defined in asm-ppc64/page.h */
	90	#define PAGE_NONE __pgprot(_PAGE_PRESENT \| _PAGE_ACCESSED)
	91
	92	#define PAGE_SHARED __pgprot(_PAGE_BASE \| _PAGE_RW \| _PAGE_USER)
	93	#define PAGE_SHARED_X __pgprot(_PAGE_BASE \| _PAGE_RW \| _PAGE_USER \| _PAGE_EXEC)
	94	#define PAGE_COPY __pgprot(_PAGE_BASE \| _PAGE_USER)
	95	#define PAGE_COPY_X __pgprot(_PAGE_BASE \| _PAGE_USER \| _PAGE_EXEC)
	96	#define PAGE_READONLY __pgprot(_PAGE_BASE \| _PAGE_USER)
	97	#define PAGE_READONLY_X __pgprot(_PAGE_BASE \| _PAGE_USER \| _PAGE_EXEC)
	98	#define PAGE_KERNEL __pgprot(_PAGE_BASE \| _PAGE_WRENABLE)
	99	#define PAGE_KERNEL_CI __pgprot(_PAGE_PRESENT \| _PAGE_ACCESSED \| \
	100	_PAGE_WRENABLE \| _PAGE_NO_CACHE \| _PAGE_GUARDED)
	101	#define PAGE_KERNEL_EXEC __pgprot(_PAGE_BASE \| _PAGE_WRENABLE \| _PAGE_EXEC)
	102
	103	#define PAGE_AGP __pgprot(_PAGE_BASE \| _PAGE_WRENABLE \| _PAGE_NO_CACHE)
	104	#define HAVE_PAGE_AGP
	105
	106	/*
	107	* This bit in a hardware PTE indicates that the page is not executable.
	108	*/
	109	#define HW_NO_EXEC _PAGE_EXEC
	110
	111	/*
	112	* POWER4 and newer have per page execute protection, older chips can only
	113	* do this on a segment (256MB) basis.
	114	*
	115	* Also, write permissions imply read permissions.
	116	* This is the closest we can get..
	117	*
	118	* Note due to the way vm flags are laid out, the bits are XWR
	119	*/
	120	#define __P000 PAGE_NONE
121	#define __P001 PAGE_READONLY
122	#define __P010 PAGE_COPY
123	#define __P011 PAGE_COPY
124	#define __P100 PAGE_READONLY_X
125	#define __P101 PAGE_READONLY_X
126	#define __P110 PAGE_COPY_X
127	#define __P111 PAGE_COPY_X
128
129	#define __S000 PAGE_NONE
130	#define __S001 PAGE_READONLY
131	#define __S010 PAGE_SHARED
132	#define __S011 PAGE_SHARED
133	#define __S100 PAGE_READONLY_X
134	#define __S101 PAGE_READONLY_X
135	#define __S110 PAGE_SHARED_X
136	#define __S111 PAGE_SHARED_X
137
138	#ifndef __ASSEMBLY__
139
140	/*
141	* ZERO_PAGE is a global shared page that is always zero: used
142	* for zero-mapped memory areas etc..
143	*/
144	extern unsigned long empty_zero_page[PAGE_SIZE/sizeof(unsigned long)];
145	#define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page))
146	#endif /* __ASSEMBLY__ */
147
148	/* shift to put page number into pte */
149	#define PTE_SHIFT (17)
150
1da177e4 LT	151	#ifdef CONFIG_HUGETLB_PAGE
	152
	153	#ifndef __ASSEMBLY__
	154	int hash_huge_page(struct mm_struct *mm, unsigned long access,
	155	unsigned long ea, unsigned long vsid, int local);
	156
	157	void hugetlb_mm_free_pgd(struct mm_struct *mm);
	158	#endif /* __ASSEMBLY__ */
	159
	160	#define HAVE_ARCH_UNMAPPED_AREA
	161	#define HAVE_ARCH_UNMAPPED_AREA_TOPDOWN
	162	#else
	163
	164	#define hash_huge_page(mm,a,ea,vsid,local) -1
	165	#define hugetlb_mm_free_pgd(mm) do {} while (0)
	166
	167	#endif
	168
	169	#ifndef __ASSEMBLY__
	170
	171	/*
	172	* Conversion functions: convert a page and protection to a page entry,
	173	* and a page entry and page directory to the page they refer to.
	174	*
	175	* mk_pte takes a (struct page *) as input
	176	*/
	177	#define mk_pte(page, pgprot) pfn_pte(page_to_pfn(page), (pgprot))
	178
1f8d419e DG	179	static inline pte_t pfn_pte(unsigned long pfn, pgprot_t pgprot)
	180	{
	181	pte_t pte;
	182
	183
	184	pte_val(pte) = (pfn << PTE_SHIFT) \| pgprot_val(pgprot);
	185	return pte;
	186	}
1da177e4 LT	187
	188	#define pte_modify(_pte, newprot) \
	189	(__pte((pte_val(_pte) & _PAGE_CHG_MASK) \| pgprot_val(newprot)))
	190
	191	#define pte_none(pte) ((pte_val(pte) & ~_PAGE_HPTEFLAGS) == 0)
	192	#define pte_present(pte) (pte_val(pte) & _PAGE_PRESENT)
	193
	194	/* pte_clear moved to later in this file */
	195
	196	#define pte_pfn(x) ((unsigned long)((pte_val(x) >> PTE_SHIFT)))
	197	#define pte_page(x) pfn_to_page(pte_pfn(x))
	198
	199	#define pmd_set(pmdp, ptep) \
1f8d419e	200	(pmd_val(*(pmdp)) = __ba_to_bpn(ptep))
1da177e4 LT	201	#define pmd_none(pmd) (!pmd_val(pmd))
	202	#define pmd_bad(pmd) (pmd_val(pmd) == 0)
	203	#define pmd_present(pmd) (pmd_val(pmd) != 0)
	204	#define pmd_clear(pmdp) (pmd_val(*(pmdp)) = 0)
1f8d419e	205	#define pmd_page_kernel(pmd) (__bpn_to_ba(pmd_val(pmd)))
1da177e4	206	#define pmd_page(pmd) virt_to_page(pmd_page_kernel(pmd))
58366af5 BH	207
	208	#define pud_set(pudp, pmdp) (pud_val(*(pudp)) = (__ba_to_bpn(pmdp)))
	209	#define pud_none(pud) (!pud_val(pud))
	210	#define pud_bad(pud) ((pud_val(pud)) == 0UL)
	211	#define pud_present(pud) (pud_val(pud) != 0UL)
	212	#define pud_clear(pudp) (pud_val(*(pudp)) = 0UL)
	213	#define pud_page(pud) (__bpn_to_ba(pud_val(pud)))
1da177e4 LT	214
	215	/*
	216	* Find an entry in a page-table-directory. We combine the address region
	217	* (the high order N bits) and the pgd portion of the address.
	218	*/
	219	/* to avoid overflow in free_pgtables we don't use PTRS_PER_PGD here */
	220	#define pgd_index(address) (((address) >> (PGDIR_SHIFT)) & 0x7ff)
	221
	222	#define pgd_offset(mm, address) ((mm)->pgd + pgd_index(address))
	223
	224	/* Find an entry in the second-level page table.. */
58366af5 BH	225	#define pmd_offset(pudp,addr) \
58366af5 BH	226	((pmd_t ) pud_page((pudp)) + (((addr) >> PMD_SHIFT) & (PTRS_PER_PMD - 1)))
1da177e4 LT	227
	228	/* Find an entry in the third-level page table.. */
	229	#define pte_offset_kernel(dir,addr) \
58366af5 BH	230	((pte_t ) pmd_page_kernel((dir)) \
58366af5 BH	231	+ (((addr) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1)))
1da177e4 LT	232
	233	#define pte_offset_map(dir,addr) pte_offset_kernel((dir), (addr))
	234	#define pte_offset_map_nested(dir,addr) pte_offset_kernel((dir), (addr))
	235	#define pte_unmap(pte) do { } while(0)
	236	#define pte_unmap_nested(pte) do { } while(0)
	237
	238	/* to find an entry in a kernel page-table-directory */
	239	/* This now only contains the vmalloc pages */
	240	#define pgd_offset_k(address) pgd_offset(&init_mm, address)
	241
	242	/* to find an entry in the ioremap page-table-directory */
	243	#define pgd_offset_i(address) (ioremap_pgd + pgd_index(address))
	244
1da177e4 LT	245	/*
	246	* The following only work if pte_present() is true.
	247	* Undefined behaviour if not..
	248	*/
	249	static inline int pte_read(pte_t pte) { return pte_val(pte) & _PAGE_USER;}
	250	static inline int pte_write(pte_t pte) { return pte_val(pte) & _PAGE_RW;}
	251	static inline int pte_exec(pte_t pte) { return pte_val(pte) & _PAGE_EXEC;}
	252	static inline int pte_dirty(pte_t pte) { return pte_val(pte) & _PAGE_DIRTY;}
	253	static inline int pte_young(pte_t pte) { return pte_val(pte) & _PAGE_ACCESSED;}
	254	static inline int pte_file(pte_t pte) { return pte_val(pte) & _PAGE_FILE;}
	255	static inline int pte_huge(pte_t pte) { return pte_val(pte) & _PAGE_HUGE;}
	256
	257	static inline void pte_uncache(pte_t pte) { pte_val(pte) \|= _PAGE_NO_CACHE; }
	258	static inline void pte_cache(pte_t pte) { pte_val(pte) &= ~_PAGE_NO_CACHE; }
	259
	260	static inline pte_t pte_rdprotect(pte_t pte) {
	261	pte_val(pte) &= ~_PAGE_USER; return pte; }
	262	static inline pte_t pte_exprotect(pte_t pte) {
	263	pte_val(pte) &= ~_PAGE_EXEC; return pte; }
	264	static inline pte_t pte_wrprotect(pte_t pte) {
	265	pte_val(pte) &= ~(_PAGE_RW); return pte; }
	266	static inline pte_t pte_mkclean(pte_t pte) {
	267	pte_val(pte) &= ~(_PAGE_DIRTY); return pte; }
	268	static inline pte_t pte_mkold(pte_t pte) {
	269	pte_val(pte) &= ~_PAGE_ACCESSED; return pte; }
	270
	271	static inline pte_t pte_mkread(pte_t pte) {
	272	pte_val(pte) \|= _PAGE_USER; return pte; }
	273	static inline pte_t pte_mkexec(pte_t pte) {
	274	pte_val(pte) \|= _PAGE_USER \| _PAGE_EXEC; return pte; }
	275	static inline pte_t pte_mkwrite(pte_t pte) {
	276	pte_val(pte) \|= _PAGE_RW; return pte; }
	277	static inline pte_t pte_mkdirty(pte_t pte) {
	278	pte_val(pte) \|= _PAGE_DIRTY; return pte; }
	279	static inline pte_t pte_mkyoung(pte_t pte) {
	280	pte_val(pte) \|= _PAGE_ACCESSED; return pte; }
	281	static inline pte_t pte_mkhuge(pte_t pte) {
	282	pte_val(pte) \|= _PAGE_HUGE; return pte; }
	283
	284	/* Atomic PTE updates */
	285	static inline unsigned long pte_update(pte_t *p, unsigned long clr)
	286	{
	287	unsigned long old, tmp;
	288
	289	__asm__ __volatile__(
	290	"1: ldarx %0,0,%3 # pte_update\n\
	291	andi. %1,%0,%6\n\
	292	bne- 1b \n\
	293	andc %1,%0,%4 \n\
	294	stdcx. %1,0,%3 \n\
	295	bne- 1b"
	296	: "=&r" (old), "=&r" (tmp), "=m" (*p)
	297	: "r" (p), "r" (clr), "m" (*p), "i" (_PAGE_BUSY)
	298	: "cc" );
	299	return old;
	300	}
	301
	302	/* PTE updating functions, this function puts the PTE in the
	303	* batch, doesn't actually triggers the hash flush immediately,
	304	* you need to call flush_tlb_pending() to do that.
	305	*/
	306	extern void hpte_update(struct mm_struct *mm, unsigned long addr, unsigned long pte,
	307	int wrprot);
	308
309	static inline int __ptep_test_and_clear_young(struct mm_struct mm, unsigned long addr, pte_t ptep)
310	{
311	unsigned long old;
312
313	if ((pte_val(*ptep) & (_PAGE_ACCESSED \| _PAGE_HASHPTE)) == 0)
314	return 0;
315	old = pte_update(ptep, _PAGE_ACCESSED);
316	if (old & _PAGE_HASHPTE) {
317	hpte_update(mm, addr, old, 0);
318	flush_tlb_pending();
319	}
320	return (old & _PAGE_ACCESSED) != 0;
321	}
322	#define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
323	#define ptep_test_and_clear_young(__vma, __addr, __ptep) \
324	({ \
325	int __r; \
326	__r = __ptep_test_and_clear_young((__vma)->vm_mm, __addr, __ptep); \
327	__r; \
328	})
329
330	/*
331	* On RW/DIRTY bit transitions we can avoid flushing the hpte. For the
332	* moment we always flush but we need to fix hpte_update and test if the
333	* optimisation is worth it.
334	*/
335	static inline int __ptep_test_and_clear_dirty(struct mm_struct mm, unsigned long addr, pte_t ptep)
336	{
337	unsigned long old;
338
339	if ((pte_val(*ptep) & _PAGE_DIRTY) == 0)
340	return 0;
341	old = pte_update(ptep, _PAGE_DIRTY);
342	if (old & _PAGE_HASHPTE)
343	hpte_update(mm, addr, old, 0);
344	return (old & _PAGE_DIRTY) != 0;
345	}
346	#define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_DIRTY
347	#define ptep_test_and_clear_dirty(__vma, __addr, __ptep) \
348	({ \
349	int __r; \
350	__r = __ptep_test_and_clear_dirty((__vma)->vm_mm, __addr, __ptep); \
351	__r; \
352	})
353
354	#define __HAVE_ARCH_PTEP_SET_WRPROTECT
355	static inline void ptep_set_wrprotect(struct mm_struct mm, unsigned long addr, pte_t ptep)
356	{
357	unsigned long old;
358
359	if ((pte_val(*ptep) & _PAGE_RW) == 0)
360	return;
361	old = pte_update(ptep, _PAGE_RW);
362	if (old & _PAGE_HASHPTE)
363	hpte_update(mm, addr, old, 0);
364	}
365
366	/*
367	* We currently remove entries from the hashtable regardless of whether
368	* the entry was young or dirty. The generic routines only flush if the
369	* entry was young or dirty which is not good enough.
370	*
371	* We should be more intelligent about this but for the moment we override
372	* these functions and force a tlb flush unconditionally
373	*/
374	#define __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSH
375	#define ptep_clear_flush_young(__vma, __address, __ptep) \
376	({ \
377	int __young = __ptep_test_and_clear_young((__vma)->vm_mm, __address, \
378	__ptep); \
379	__young; \
380	})
381
382	#define __HAVE_ARCH_PTEP_CLEAR_DIRTY_FLUSH
383	#define ptep_clear_flush_dirty(__vma, __address, __ptep) \
384	({ \
385	int __dirty = __ptep_test_and_clear_dirty((__vma)->vm_mm, __address, \
386	__ptep); \
387	flush_tlb_page(__vma, __address); \
388	__dirty; \
389	})
390
391	#define __HAVE_ARCH_PTEP_GET_AND_CLEAR
392	static inline pte_t ptep_get_and_clear(struct mm_struct mm, unsigned long addr, pte_t ptep)
393	{
394	unsigned long old = pte_update(ptep, ~0UL);
395
396	if (old & _PAGE_HASHPTE)
397	hpte_update(mm, addr, old, 0);
398	return __pte(old);
399	}
400
401	static inline void pte_clear(struct mm_struct mm, unsigned long addr, pte_t ptep)
402	{
403	unsigned long old = pte_update(ptep, ~0UL);
404
405	if (old & _PAGE_HASHPTE)
406	hpte_update(mm, addr, old, 0);
407	}
408
409	/*
410	* set_pte stores a linux PTE into the linux page table.
411	*/
412	static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
413	pte_t *ptep, pte_t pte)
414	{
415	if (pte_present(*ptep)) {
416	pte_clear(mm, addr, ptep);
417	flush_tlb_pending();
418	}
1f8d419e	419	*ptep = __pte(pte_val(pte) & ~_PAGE_HPTEFLAGS);
1da177e4 LT	420	}
	421
	422	/* Set the dirty and/or accessed bits atomically in a linux PTE, this
	423	* function doesn't need to flush the hash entry
	424	*/
	425	#define __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
	426	static inline void __ptep_set_access_flags(pte_t *ptep, pte_t entry, int dirty)
	427	{
	428	unsigned long bits = pte_val(entry) &
	429	(_PAGE_DIRTY \| _PAGE_ACCESSED \| _PAGE_RW \| _PAGE_EXEC);
	430	unsigned long old, tmp;
	431
	432	__asm__ __volatile__(
	433	"1: ldarx %0,0,%4\n\
	434	andi. %1,%0,%6\n\
	435	bne- 1b \n\
	436	or %0,%3,%0\n\
	437	stdcx. %0,0,%4\n\
	438	bne- 1b"
	439	:"=&r" (old), "=&r" (tmp), "=m" (*ptep)
	440	:"r" (bits), "r" (ptep), "m" (*ptep), "i" (_PAGE_BUSY)
	441	:"cc");
	442	}
	443	#define ptep_set_access_flags(__vma, __address, __ptep, __entry, __dirty) \
	444	do { \
	445	__ptep_set_access_flags(__ptep, __entry, __dirty); \
	446	flush_tlb_page_nohash(__vma, __address); \
	447	} while(0)
	448
	449	/*
	450	* Macro to mark a page protection value as "uncacheable".
	451	*/
	452	#define pgprot_noncached(prot) (__pgprot(pgprot_val(prot) \| _PAGE_NO_CACHE \| _PAGE_GUARDED))
	453
	454	struct file;
	455	extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long addr,
	456	unsigned long size, pgprot_t vma_prot);
	457	#define __HAVE_PHYS_MEM_ACCESS_PROT
	458
	459	#define __HAVE_ARCH_PTE_SAME
	460	#define pte_same(A,B) (((pte_val(A) ^ pte_val(B)) & ~_PAGE_HPTEFLAGS) == 0)
	461
	462	extern unsigned long ioremap_bot, ioremap_base;
	463
1da177e4 LT	464	#define pmd_ERROR(e) \
	465	printk("%s:%d: bad pmd %08x.\n", __FILE__, __LINE__, pmd_val(e))
	466	#define pgd_ERROR(e) \
	467	printk("%s:%d: bad pgd %08x.\n", __FILE__, __LINE__, pgd_val(e))
	468
1f8d419e DG	469	extern pgd_t swapper_pg_dir[];
1f8d419e DG	470	extern pgd_t ioremap_dir[];
1da177e4 LT	471
	472	extern void paging_init(void);
	473
3bf5ee95 HD	474	/*
	475	* Because the huge pgtables are only 2 level, they can take
	476	* at most around 4M, much less than one hugepage which the
	477	* process is presumably entitled to use. So we don't bother
	478	* freeing up the pagetables on unmap, and wait until
	479	* destroy_context() to clean up the lot.
	480	*/
	481	#define hugetlb_free_pgd_range(tlb, addr, end, floor, ceiling) \
	482	do { } while (0)
1da177e4 LT	483
	484	/*
	485	* This gets called at the end of handling a page fault, when
	486	* the kernel has put a new PTE into the page table for the process.
	487	* We use it to put a corresponding HPTE into the hash table
	488	* ahead of time, instead of waiting for the inevitable extra
	489	* hash-table miss exception.
	490	*/
	491	struct vm_area_struct;
	492	extern void update_mmu_cache(struct vm_area_struct *, unsigned long, pte_t);
	493
	494	/* Encode and de-code a swap entry */
	495	#define __swp_type(entry) (((entry).val >> 1) & 0x3f)
	496	#define __swp_offset(entry) ((entry).val >> 8)
	497	#define __swp_entry(type, offset) ((swp_entry_t) { ((type) << 1) \| ((offset) << 8) })
	498	#define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) >> PTE_SHIFT })
	499	#define __swp_entry_to_pte(x) ((pte_t) { (x).val << PTE_SHIFT })
	500	#define pte_to_pgoff(pte) (pte_val(pte) >> PTE_SHIFT)
	501	#define pgoff_to_pte(off) ((pte_t) {((off) << PTE_SHIFT)\|_PAGE_FILE})
	502	#define PTE_FILE_MAX_BITS (BITS_PER_LONG - PTE_SHIFT)
	503
	504	/*
	505	* kern_addr_valid is intended to indicate whether an address is a valid
	506	* kernel address. Most 32-bit archs define it as always true (like this)
	507	* but most 64-bit archs actually perform a test. What should we do here?
	508	* The only use is in fs/ncpfs/dir.c
	509	*/
	510	#define kern_addr_valid(addr) (1)
	511
1da177e4 LT	512	#define io_remap_pfn_range(vma, vaddr, pfn, size, prot) \
	513	remap_pfn_range(vma, vaddr, pfn, size, prot)
	514
1da177e4 LT	515	void pgtable_cache_init(void);
1da177e4 LT	516
1da177e4 LT	517	/*
	518	* find_linux_pte returns the address of a linux pte for a given
	519	* effective address and directory. If not found, it returns zero.
	520	*/
	521	static inline pte_t find_linux_pte(pgd_t pgdir, unsigned long ea)
	522	{
	523	pgd_t *pg;
58366af5	524	pud_t *pu;
1da177e4 LT	525	pmd_t *pm;
	526	pte_t *pt = NULL;
	527	pte_t pte;
	528
	529	pg = pgdir + pgd_index(ea);
	530	if (!pgd_none(*pg)) {
58366af5 BH	531	pu = pud_offset(pg, ea);
	532	if (!pud_none(*pu)) {
	533	pm = pmd_offset(pu, ea);
	534	if (pmd_present(*pm)) {
	535	pt = pte_offset_kernel(pm, ea);
	536	pte = *pt;
	537	if (!pte_present(pte))
	538	pt = NULL;
	539	}
1da177e4 LT	540	}
	541	}
	542
	543	return pt;
	544	}
	545
	546	#include <asm-generic/pgtable.h>
	547
	548	#endif /* __ASSEMBLY__ */
	549
	550	#endif /* _PPC64_PGTABLE_H */