Import 2.3.13pre6

[davej-history.git] / include / asm-ppc / pgtable.h

#include <linux/config.h>

#ifndef _PPC_PGTABLE_H
#define _PPC_PGTABLE_H

#ifndef __ASSEMBLY__
#include <linux/mm.h>
#include <asm/processor.h>              /* For TASK_SIZE */
#include <asm/mmu.h>
#include <asm/page.h>

extern void local_flush_tlb_all(void);
extern void local_flush_tlb_mm(struct mm_struct *mm);
extern void local_flush_tlb_page(struct vm_area_struct *vma, unsigned long vmaddr);
extern void local_flush_tlb_range(struct mm_struct *mm, unsigned long start,
                            unsigned long end);

#define flush_tlb_all local_flush_tlb_all
#define flush_tlb_mm local_flush_tlb_mm
#define flush_tlb_page local_flush_tlb_page
#define flush_tlb_range local_flush_tlb_range

extern __inline__ void flush_tlb_pgtables(struct mm_struct *mm, unsigned long start, unsigned long end)
{
        /* PPC has hw page tables. */
}

/*
 * No cache flushing is required when address mappings are
 * changed, because the caches on PowerPCs are physically
 * addressed.
 * Also, when SMP we use the coherency (M) bit of the
 * BATs and PTEs.  -- Cort
 */
#define flush_cache_all()               do { } while (0)
#define flush_cache_mm(mm)              do { } while (0)
#define flush_cache_range(mm, a, b)     do { } while (0)
#define flush_cache_page(vma, p)        do { } while (0)

extern void flush_icache_range(unsigned long, unsigned long);
extern void flush_page_to_ram(unsigned long);

extern unsigned long va_to_phys(unsigned long address);
extern pte_t *va_to_pte(struct task_struct *tsk, unsigned long address);
extern unsigned long ioremap_bot, ioremap_base;
#endif /* __ASSEMBLY__ */
/*
 * The PowerPC MMU uses a hash table containing PTEs, together with
 * a set of 16 segment registers (on 32-bit implementations), to define
 * the virtual to physical address mapping.
 *
 * We use the hash table as an extended TLB, i.e. a cache of currently
 * active mappings.  We maintain a two-level page table tree, much like
 * that used by the i386, for the sake of the Linux memory management code.
 * Low-level assembler code in head.S (procedure hash_page) is responsible
 * for extracting ptes from the tree and putting them into the hash table
 * when necessary, and updating the accessed and modified bits in the
 * page table tree.
 *
 * The PowerPC MPC8xx uses a TLB with hardware assisted, software tablewalk.
 * We also use the two level tables, but we can put the real bits in them
 * needed for the TLB and tablewalk.  These definitions require Mx_CTR.PPM = 0,
 * Mx_CTR.PPCS = 0, and MD_CTR.TWAM = 1.  The level 2 descriptor has
 * additional page protection (when Mx_CTR.PPCS = 1) that allows TLB hit
 * based upon user/super access.  The TLB does not have accessed nor write
 * protect.  We assume that if the TLB get loaded with an entry it is
 * accessed, and overload the changed bit for write protect.  We use
 * two bits in the software pte that are supposed to be set to zero in
 * the TLB entry (24 and 25) for these indicators.  Although the level 1
 * descriptor contains the guarded and writethrough/copyback bits, we can
 * set these at the page level since they get copied from the Mx_TWC
 * register when the TLB entry is loaded.  We will use bit 27 for guard, since
 * that is where it exists in the MD_TWC, and bit 26 for writethrough.
 * These will get masked from the level 2 descriptor at TLB load time, and
 * copied to the MD_TWC before it gets loaded.
 */

/* PMD_SHIFT determines the size of the area mapped by the second-level page tables */
#define PMD_SHIFT       22
#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     22
#define PGDIR_SIZE      (1UL << PGDIR_SHIFT)
#define PGDIR_MASK      (~(PGDIR_SIZE-1))

/*
 * entries per page directory level: our page-table tree is two-level, so
 * we don't really have any PMD directory.
 */
#define PTRS_PER_PTE    1024
#define PTRS_PER_PMD    1
#define PTRS_PER_PGD    1024
#define USER_PTRS_PER_PGD       (TASK_SIZE / PGDIR_SIZE)

/* Just any arbitrary offset to the start of the vmalloc VM area: the
 * current 64MB value just means that there will be a 64MB "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. ;)
 *
 * We no longer map larger than phys RAM with the BATs so we don't have
 * to worry about the VMALLOC_OFFSET causing problems.  We do have to worry
 * about clashes between our early calls to ioremap() that start growing down
 * from ioremap_base being run into the VM area allocations (growing upwards
 * from VMALLOC_START).  For this reason we have ioremap_bot to check when
 * we actually run into our mappings setup in the early boot with the VM
 * system.  This really does become a problem for machines with good amounts
 * of RAM.  -- Cort
 */
#define VMALLOC_OFFSET (0x4000000) /* 64M */
#define VMALLOC_START ((((long)high_memory + VMALLOC_OFFSET) & ~(VMALLOC_OFFSET-1)))
#define VMALLOC_VMADDR(x) ((unsigned long)(x))
#define VMALLOC_END     ioremap_bot

/*
 * Bits in a linux-style PTE.  These match the bits in the
 * (hardware-defined) PowerPC PTE as closely as possible.
 */
#ifndef CONFIG_8xx
#define _PAGE_PRESENT   0x001   /* software: pte contains a translation */
#define _PAGE_USER      0x002   /* matches one of the PP bits */
#define _PAGE_RW        0x004   /* software: user write access allowed */
#define _PAGE_GUARDED   0x008
#define _PAGE_COHERENT  0x010   /* M: enforce memory coherence (SMP systems) */
#define _PAGE_NO_CACHE  0x020   /* I: cache inhibit */
#define _PAGE_WRITETHRU 0x040   /* W: cache write-through */
#define _PAGE_DIRTY     0x080   /* C: page changed */
#define _PAGE_ACCESSED  0x100   /* R: page referenced */
#define _PAGE_HWWRITE   0x200   /* software: _PAGE_RW & _PAGE_DIRTY */
#define _PAGE_SHARED    0

#else
#define _PAGE_PRESENT   0x0001  /* Page is valid */
#define _PAGE_NO_CACHE  0x0002  /* I: cache inhibit */
#define _PAGE_SHARED    0x0004  /* No ASID (context) compare */

/* These four software bits must be masked out when the entry is loaded
 * into the TLB.
 */
#define _PAGE_GUARDED   0x0010  /* software: guarded access */
#define _PAGE_WRITETHRU 0x0020  /* software: use writethrough cache */
#define _PAGE_RW        0x0040  /* software: user write access allowed */
#define _PAGE_ACCESSED  0x0080  /* software: page referenced */

#define _PAGE_DIRTY     0x0100  /* C: page changed (write protect) */
#define _PAGE_USER      0x0800  /* One of the PP bits, the other must be 0 */

/* This is used to enable or disable the actual hardware write
 * protection.
 */
#define _PAGE_HWWRITE   _PAGE_DIRTY

#endif /* CONFIG_8xx */

#define _PAGE_CHG_MASK  (PAGE_MASK | _PAGE_ACCESSED | _PAGE_DIRTY)

#ifdef __SMP__
#define _PAGE_BASE      _PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_COHERENT
#else
#define _PAGE_BASE      _PAGE_PRESENT | _PAGE_ACCESSED
#endif
#define _PAGE_WRENABLE  _PAGE_RW | _PAGE_DIRTY | _PAGE_HWWRITE

#define PAGE_NONE       __pgprot(_PAGE_PRESENT | _PAGE_ACCESSED)

#define PAGE_SHARED     __pgprot(_PAGE_BASE | _PAGE_RW | _PAGE_USER | \
                                 _PAGE_SHARED)
#define PAGE_COPY       __pgprot(_PAGE_BASE | _PAGE_USER)
#define PAGE_READONLY   __pgprot(_PAGE_BASE | _PAGE_USER)
#define PAGE_KERNEL     __pgprot(_PAGE_BASE | _PAGE_WRENABLE | _PAGE_SHARED)
#define PAGE_KERNEL_CI  __pgprot(_PAGE_BASE | _PAGE_WRENABLE | _PAGE_SHARED | \
                                 _PAGE_NO_CACHE )

/*
 * The PowerPC can only do execute protection on a segment (256MB) basis,
 * not on a page basis.  So we consider execute permission the same as 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
#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

/*
 * BAD_PAGETABLE is used when we need a bogus page-table, while
 * BAD_PAGE is used for a bogus page.
 *
 * ZERO_PAGE is a global shared page that is always zero: used
 * for zero-mapped memory areas etc..
 */
#ifndef __ASSEMBLY__
extern pte_t __bad_page(void);
extern pte_t * __bad_pagetable(void);

extern unsigned long empty_zero_page[1024];
#endif __ASSEMBLY__
#define BAD_PAGETABLE   __bad_pagetable()
#define BAD_PAGE        __bad_page()
#define ZERO_PAGE(vaddr)        ((unsigned long) empty_zero_page)

/* number of bits that fit into a memory pointer */
#define BITS_PER_PTR    (8*sizeof(unsigned long))

/* to align the pointer to a pointer address */
#define PTR_MASK        (~(sizeof(void*)-1))

/* sizeof(void*) == 1<<SIZEOF_PTR_LOG2 */
/* 64-bit machines, beware!  SRB. */
#define SIZEOF_PTR_LOG2 2

/* to set the page-dir */
/* tsk is a task_struct and pgdir is a pte_t */
#ifndef CONFIG_8xx
#define SET_PAGE_DIR(tsk,pgdir)  \
        ((tsk)->tss.pg_tables = (unsigned long *)(pgdir))
#else /* CONFIG_8xx */     
#define SET_PAGE_DIR(tsk,pgdir)  \
 do { \
        unsigned long __pgdir = (unsigned long)pgdir; \
        ((tsk)->tss.pg_tables = (unsigned long *)(__pgdir)); \
        asm("mtspr %0,%1 \n\t" : : "i"(M_TWB), "r"(__pa(__pgdir))); \
 } while (0)
#endif /* CONFIG_8xx */
     
#ifndef __ASSEMBLY__
extern inline int pte_none(pte_t pte)           { return !pte_val(pte); }
extern inline int pte_present(pte_t pte)        { return pte_val(pte) & _PAGE_PRESENT; }
extern inline void pte_clear(pte_t *ptep)       { pte_val(*ptep) = 0; }

extern inline int pmd_none(pmd_t pmd)           { return !pmd_val(pmd); }
extern inline int pmd_bad(pmd_t pmd)            { return (pmd_val(pmd) & ~PAGE_MASK) != 0; }
extern inline int pmd_present(pmd_t pmd)        { return (pmd_val(pmd) & PAGE_MASK) != 0; }
extern inline void pmd_clear(pmd_t * pmdp)      { pmd_val(*pmdp) = 0; }


/*
 * 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)
 */
extern inline int pgd_none(pgd_t pgd)           { return 0; }
extern inline int pgd_bad(pgd_t pgd)            { return 0; }
extern inline int pgd_present(pgd_t pgd)        { return 1; }
extern inline void pgd_clear(pgd_t * pgdp)      { }

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

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

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

extern inline pte_t pte_mkread(pte_t pte) {
        pte_val(pte) |= _PAGE_USER; return pte; }
extern inline pte_t pte_mkexec(pte_t pte) {
        pte_val(pte) |= _PAGE_USER; return pte; }
extern inline pte_t pte_mkwrite(pte_t pte)
{
        pte_val(pte) |= _PAGE_RW;
        if (pte_val(pte) & _PAGE_DIRTY)
                pte_val(pte) |= _PAGE_HWWRITE;
        return pte;
}
extern inline pte_t pte_mkdirty(pte_t pte)
{
        pte_val(pte) |= _PAGE_DIRTY;
        if (pte_val(pte) & _PAGE_RW)
                pte_val(pte) |= _PAGE_HWWRITE;
        return pte;
}
extern inline pte_t pte_mkyoung(pte_t pte) {
        pte_val(pte) |= _PAGE_ACCESSED; return pte; }

/* Certain architectures need to do special things when pte's
 * within a page table are directly modified.  Thus, the following
 * hook is made available.
 */
#if 1
#define set_pte(pteptr, pteval) ((*(pteptr)) = (pteval))
#else
extern inline void set_pte(pte_t *pteptr, pte_t pteval)
{
        unsigned long val = pte_val(pteval);
        extern void xmon(void *);

        if ((val & _PAGE_PRESENT) && ((val < 0x111000 || (val & 0x800)
            || ((val & _PAGE_HWWRITE) && (~val & (_PAGE_RW|_PAGE_DIRTY)))) {
                printk("bad pte val %lx ptr=%p\n", val, pteptr);
                xmon(0);
        }
        *pteptr = pteval;
}
#endif

/*
 * 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 pte_t mk_pte_phys(unsigned long page, pgprot_t pgprot)
{ pte_t pte; pte_val(pte) = (page) | pgprot_val(pgprot); return pte; }

extern inline pte_t mk_pte(unsigned long page, pgprot_t pgprot)
{ pte_t pte; pte_val(pte) = __pa(page) | pgprot_val(pgprot); return pte; }

extern inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
{ pte_val(pte) = (pte_val(pte) & _PAGE_CHG_MASK) | pgprot_val(newprot); return pte; }

extern inline unsigned long pte_page(pte_t pte)
{ return (unsigned long) __va(pte_val(pte) & PAGE_MASK); }

extern inline unsigned long pmd_page(pmd_t pmd)
{ return pmd_val(pmd); }


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

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

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

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

/*
 * This is handled very differently on the PPC since out page tables
 * are all 0's and I want to be able to use these zero'd pages elsewhere
 * as well - it gives us quite a speedup.
 *
 * Note that the SMP/UP versions are the same but we don't need a
 * per cpu list of zero pages because we do the zero-ing with the cache
 * off and the access routines are lock-free but the pgt cache stuff
 * is per-cpu since it isn't done with any lock-free access routines
 * (although I think we need arch-specific routines so I can do lock-free).
 *
 * I need to generalize this so we can use it for other arch's as well.
 * -- Cort
 */
#ifdef __SMP__
#define quicklists      cpu_data[smp_processor_id()]
#else
extern struct pgtable_cache_struct {
        unsigned long *pgd_cache;
        unsigned long *pte_cache;
        unsigned long pgtable_cache_sz;
} quicklists;
#endif

#define pgd_quicklist           (quicklists.pgd_cache)
#define pmd_quicklist           ((unsigned long *)0)
#define pte_quicklist           (quicklists.pte_cache)
#define pgtable_cache_size      (quicklists.pgtable_cache_sz)

extern unsigned long *zero_cache;    /* head linked list of pre-zero'd pages */
extern unsigned long zero_sz;        /* # currently pre-zero'd pages */
extern unsigned long zeropage_hits;  /* # zero'd pages request that we've done */
extern unsigned long zeropage_calls; /* # zero'd pages request that've been made */
extern unsigned long zerototal;      /* # pages zero'd over time */

#define zero_quicklist          (zero_cache)
#define zero_cache_sz           (zero_sz)
#define zero_cache_calls        (zeropage_calls)
#define zero_cache_hits         (zeropage_hits)
#define zero_cache_total        (zerototal)

/* return a pre-zero'd page from the list, return NULL if none available -- Cort */
extern unsigned long get_zero_page_fast(void);

extern __inline__ pgd_t *get_pgd_slow(void)
{
        pgd_t *ret/* = (pgd_t *)__get_free_page(GFP_KERNEL)*/, *init;

        if ( (ret = (pgd_t *)get_zero_page_fast()) == NULL )
        {
                if ( (ret = (pgd_t *)__get_free_page(GFP_KERNEL)) != NULL )
                        memset (ret, 0, USER_PTRS_PER_PGD * sizeof(pgd_t));
        }
        if (ret) {
                init = pgd_offset(&init_mm, 0);
                /*memset (ret, 0, USER_PTRS_PER_PGD * sizeof(pgd_t));*/
                memcpy (ret + USER_PTRS_PER_PGD, init + USER_PTRS_PER_PGD,
                        (PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t));
        }
        return ret;
}

extern __inline__ pgd_t *get_pgd_fast(void)
{
        unsigned long *ret;

        if((ret = pgd_quicklist) != NULL) {
                pgd_quicklist = (unsigned long *)(*ret);
                ret[0] = ret[1];
                pgtable_cache_size--;
        } else
                ret = (unsigned long *)get_pgd_slow();
        return (pgd_t *)ret;
}

extern __inline__ void free_pgd_fast(pgd_t *pgd)
{
        *(unsigned long *)pgd = (unsigned long) pgd_quicklist;
        pgd_quicklist = (unsigned long *) pgd;
        pgtable_cache_size++;
}

extern __inline__ void free_pgd_slow(pgd_t *pgd)
{
        free_page((unsigned long)pgd);
}

extern pte_t *get_pte_slow(pmd_t *pmd, unsigned long address_preadjusted);

extern __inline__ pte_t *get_pte_fast(void)
{
        unsigned long *ret;

        if((ret = (unsigned long *)pte_quicklist) != NULL) {
                pte_quicklist = (unsigned long *)(*ret);
                ret[0] = ret[1];
                pgtable_cache_size--;
         }
        return (pte_t *)ret;
}

extern __inline__ void free_pte_fast(pte_t *pte)
{
        *(unsigned long *)pte = (unsigned long) pte_quicklist;
        pte_quicklist = (unsigned long *) pte;
        pgtable_cache_size++;
}

extern __inline__ void free_pte_slow(pte_t *pte)
{
        free_page((unsigned long)pte);
}

/* We don't use pmd cache, so this is a dummy routine */
extern __inline__ pmd_t *get_pmd_fast(void)
{
        return (pmd_t *)0;
}

extern __inline__ void free_pmd_fast(pmd_t *pmd)
{
}

extern __inline__ void free_pmd_slow(pmd_t *pmd)
{
}

extern void __bad_pte(pmd_t *pmd);

#define pte_free_kernel(pte)    free_pte_fast(pte)
#define pte_free(pte)           free_pte_fast(pte)
#define pgd_free(pgd)           free_pgd_fast(pgd)
#define pgd_alloc()             get_pgd_fast()

extern inline pte_t * pte_alloc(pmd_t * pmd, unsigned long address)
{
        address = (address >> PAGE_SHIFT) & (PTRS_PER_PTE - 1);
        if (pmd_none(*pmd)) {
                pte_t * page = (pte_t *) get_pte_fast();
                
                if (!page)
                        return get_pte_slow(pmd, address);
                pmd_val(*pmd) = (unsigned long) page;
                return page + address;
        }
        if (pmd_bad(*pmd)) {
                __bad_pte(pmd);
                return NULL;
        }
        return (pte_t *) pmd_page(*pmd) + address;
}

/*
 * allocating and freeing a pmd is trivial: the 1-entry pmd is
 * inside the pgd, so has no extra memory associated with it.
 */
extern inline void pmd_free(pmd_t * pmd)
{
}

extern inline pmd_t * pmd_alloc(pgd_t * pgd, unsigned long address)
{
        return (pmd_t *) pgd;
}

#define pmd_free_kernel         pmd_free
#define pmd_alloc_kernel        pmd_alloc
#define pte_alloc_kernel        pte_alloc

extern int do_check_pgt_cache(int, int);

extern inline void set_pgdir(unsigned long address, pgd_t entry)
{
        struct task_struct * p;
        pgd_t *pgd;
#ifdef __SMP__
        int i;
#endif  
        
        read_lock(&tasklist_lock);
        for_each_task(p) {
                if (!p->mm)
                        continue;
                *pgd_offset(p->mm,address) = entry;
        }
        read_unlock(&tasklist_lock);
#ifndef __SMP__
        for (pgd = (pgd_t *)pgd_quicklist; pgd; pgd = (pgd_t *)*(unsigned long *)pgd)
                pgd[address >> PGDIR_SHIFT] = entry;
#else
        /* To pgd_alloc/pgd_free, one holds master kernel lock and so does our callee, so we can
           modify pgd caches of other CPUs as well. -jj */
        for (i = 0; i < NR_CPUS; i++)
                for (pgd = (pgd_t *)cpu_data[i].pgd_cache; pgd; pgd = (pgd_t *)*(unsigned long *)pgd)
                        pgd[address >> PGDIR_SHIFT] = entry;
#endif
}

extern pgd_t swapper_pg_dir[1024];

extern __inline__ pte_t *find_pte(struct mm_struct *mm,unsigned long va)
{
        pgd_t *dir;
        pmd_t *pmd;
        pte_t *pte;

        va &= PAGE_MASK;
        
        dir = pgd_offset( mm, va );
        if (dir)
        {
                pmd = pmd_offset(dir, va & PAGE_MASK);
                if (pmd && pmd_present(*pmd))
                {
                        pte = pte_offset(pmd, va);
                        if (pte && pte_present(*pte))
                        {                       
                                pte_uncache(*pte);
                                flush_tlb_page(find_vma(mm,va),va);
                        }
                }
        }
        return pte;
}

/*
 * Page tables may have changed.  We don't need to do anything here
 * as entries are faulted into the hash table by the low-level
 * data/instruction access exception handlers.
 */
#define update_mmu_cache(vma, addr, pte)        do { } while (0)

/*
 * When flushing the tlb entry for a page, we also need to flush the
 * hash table entry.  flush_hash_page is assembler (for speed) in head.S.
 */
extern void flush_hash_segments(unsigned low_vsid, unsigned high_vsid);
extern void flush_hash_page(unsigned context, unsigned long va);


#define SWP_TYPE(entry) (((entry) >> 1) & 0x7f)
#define SWP_OFFSET(entry) ((entry) >> 8)
#define SWP_ENTRY(type,offset) (((type) << 1) | ((offset) << 8))

#define module_map      vmalloc
#define module_unmap    vfree

/* CONFIG_APUS */
/* For virtual address to physical address conversion */
extern void cache_clear(__u32 addr, int length);
extern void cache_push(__u32 addr, int length);
extern int mm_end_of_chunk (unsigned long addr, int len);
extern unsigned long iopa(unsigned long addr);
extern unsigned long mm_ptov(unsigned long addr) __attribute__ ((const));

/* Values for nocacheflag and cmode */
/* These are not used by the APUS kernel_map, but prevents
   compilation errors. */
#define KERNELMAP_FULL_CACHING          0
#define KERNELMAP_NOCACHE_SER           1
#define KERNELMAP_NOCACHE_NONSER        2
#define KERNELMAP_NO_COPYBACK           3

/*
 * Map some physical address range into the kernel address space.
 */
extern unsigned long kernel_map(unsigned long paddr, unsigned long size,
                                int nocacheflag, unsigned long *memavailp );

/*
 * Set cache mode of (kernel space) address range. 
 */
extern void kernel_set_cachemode (unsigned long address, unsigned long size,
                                 unsigned int cmode);

/* 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)

#endif __ASSEMBLY__
#endif /* _PPC_PGTABLE_H */