motorola_pgtable.h

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#ifndef _MOTOROLA_PGTABLE_H
#define _MOTOROLA_PGTABLE_H


/*
 * Definitions for MMU descriptors
 */
#define _PAGE_PRESENT   0x001
#define _PAGE_SHORT 0x002
#define _PAGE_RONLY 0x004
#define _PAGE_READWRITE 0x000
#define _PAGE_ACCESSED  0x008
#define _PAGE_DIRTY 0x010
#define _PAGE_SUPER 0x080   /* 68040 supervisor only */
#define _PAGE_GLOBAL040 0x400   /* 68040 global bit, used for kva descs */
#define _PAGE_NOCACHE030 0x040  /* 68030 no-cache mode */
#define _PAGE_NOCACHE   0x060   /* 68040 cache mode, non-serialized */
#define _PAGE_NOCACHE_S 0x040   /* 68040 no-cache mode, serialized */
#define _PAGE_CACHE040  0x020   /* 68040 cache mode, cachable, copyback */
#define _PAGE_CACHE040W 0x000   /* 68040 cache mode, cachable, write-through */

#define _DESCTYPE_MASK  0x003

#define _CACHEMASK040   (~0x060)
#define _TABLE_MASK (0xfffffe00)

#define _PAGE_TABLE (_PAGE_SHORT)
#define _PAGE_CHG_MASK  (PAGE_MASK | _PAGE_ACCESSED | _PAGE_DIRTY | _PAGE_NOCACHE)

#define _PAGE_PROTNONE  0x004
#define _PAGE_FILE  0x008   /* pagecache or swap? */

#ifndef __ASSEMBLY__

/* This is the cache mode to be used for pages containing page descriptors for
 * processors >= '040. It is in pte_mknocache(), and the variable is defined
 * and initialized in head.S */
extern int m68k_pgtable_cachemode;

/* This is the cache mode for normal pages, for supervisor access on
 * processors >= '040. It is used in pte_mkcache(), and the variable is
 * defined and initialized in head.S */

#if defined(CPU_M68060_ONLY) && defined(CONFIG_060_WRITETHROUGH)
#define m68k_supervisor_cachemode _PAGE_CACHE040W
#elif defined(CPU_M68040_OR_M68060_ONLY)
#define m68k_supervisor_cachemode _PAGE_CACHE040
#elif defined(CPU_M68020_OR_M68030_ONLY)
#define m68k_supervisor_cachemode 0
#else
extern int m68k_supervisor_cachemode;
#endif

#if defined(CPU_M68040_OR_M68060_ONLY)
#define mm_cachebits _PAGE_CACHE040
#elif defined(CPU_M68020_OR_M68030_ONLY)
#define mm_cachebits 0
#else
extern unsigned long mm_cachebits;
#endif

#define PAGE_NONE   __pgprot(_PAGE_PROTNONE | _PAGE_ACCESSED | mm_cachebits)
#define PAGE_SHARED __pgprot(_PAGE_PRESENT | _PAGE_ACCESSED | mm_cachebits)
#define PAGE_COPY   __pgprot(_PAGE_PRESENT | _PAGE_RONLY | _PAGE_ACCESSED | mm_cachebits)
#define PAGE_READONLY   __pgprot(_PAGE_PRESENT | _PAGE_RONLY | _PAGE_ACCESSED | mm_cachebits)
#define PAGE_KERNEL __pgprot(_PAGE_PRESENT | _PAGE_DIRTY | _PAGE_ACCESSED | mm_cachebits)

/* Alternate definitions that are compile time constants, for
   initializing protection_map.  The cachebits are fixed later.  */
#define PAGE_NONE_C __pgprot(_PAGE_PROTNONE | _PAGE_ACCESSED)
#define PAGE_SHARED_C   __pgprot(_PAGE_PRESENT | _PAGE_ACCESSED)
#define PAGE_COPY_C __pgprot(_PAGE_PRESENT | _PAGE_RONLY | _PAGE_ACCESSED)
#define PAGE_READONLY_C __pgprot(_PAGE_PRESENT | _PAGE_RONLY | _PAGE_ACCESSED)

/*
 * The m68k can't do page protection for execute, and considers that the same are read.
 * Also, write permissions imply read permissions. This is the closest we can get..
 */
#define __P000  PAGE_NONE_C
#define __P001  PAGE_READONLY_C
#define __P010  PAGE_COPY_C
#define __P011  PAGE_COPY_C
#define __P100  PAGE_READONLY_C
#define __P101  PAGE_READONLY_C
#define __P110  PAGE_COPY_C
#define __P111  PAGE_COPY_C

#define __S000  PAGE_NONE_C
#define __S001  PAGE_READONLY_C
#define __S010  PAGE_SHARED_C
#define __S011  PAGE_SHARED_C
#define __S100  PAGE_READONLY_C
#define __S101  PAGE_READONLY_C
#define __S110  PAGE_SHARED_C
#define __S111  PAGE_SHARED_C

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

static 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;
}

static inline void pmd_set(pmd_t *pmdp, pte_t *ptep)
{
    unsigned long ptbl = virt_to_phys(ptep) | _PAGE_TABLE | _PAGE_ACCESSED;
    unsigned long *ptr = pmdp->pmd;
    short i = 16;
    while (--i >= 0) {
        *ptr++ = ptbl;
        ptbl += (sizeof(pte_t)*PTRS_PER_PTE/16);
    }
}

static inline void pgd_set(pgd_t *pgdp, pmd_t *pmdp)
{
    pgd_val(*pgdp) = _PAGE_TABLE | _PAGE_ACCESSED | __pa(pmdp);
}

#define __pte_page(pte) ((unsigned long)__va(pte_val(pte) & PAGE_MASK))
#define __pmd_page(pmd) ((unsigned long)__va(pmd_val(pmd) & _TABLE_MASK))
#define __pgd_page(pgd) ((unsigned long)__va(pgd_val(pgd) & _TABLE_MASK))


#define pte_none(pte)       (!pte_val(pte))
#define pte_present(pte)    (pte_val(pte) & (_PAGE_PRESENT | _PAGE_PROTNONE))
#define pte_clear(mm,addr,ptep)     ({ pte_val(*(ptep)) = 0; })

#define pte_page(pte)       virt_to_page(__va(pte_val(pte)))
#define pte_pfn(pte)        (pte_val(pte) >> PAGE_SHIFT)
#define pfn_pte(pfn, prot)  __pte(((pfn) << PAGE_SHIFT) | pgprot_val(prot))

#define pmd_none(pmd)       (!pmd_val(pmd))
#define pmd_bad(pmd)        ((pmd_val(pmd) & _DESCTYPE_MASK) != _PAGE_TABLE)
#define pmd_present(pmd)    (pmd_val(pmd) & _PAGE_TABLE)
#define pmd_clear(pmdp) ({          \
    unsigned long *__ptr = pmdp->pmd;   \
    short __i = 16;             \
    while (--__i >= 0)          \
        *__ptr++ = 0;           \
})
#define pmd_page(pmd)       virt_to_page(__va(pmd_val(pmd)))


#define pgd_none(pgd)       (!pgd_val(pgd))
#define pgd_bad(pgd)        ((pgd_val(pgd) & _DESCTYPE_MASK) != _PAGE_TABLE)
#define pgd_present(pgd)    (pgd_val(pgd) & _PAGE_TABLE)
#define pgd_clear(pgdp)     ({ pgd_val(*pgdp) = 0; })
#define pgd_page(pgd)       (mem_map + ((unsigned long)(__va(pgd_val(pgd)) - PAGE_OFFSET) >> PAGE_SHIFT))

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


/*
 * The following only work if pte_present() is true.
 * Undefined behaviour if not..
 */
static inline int pte_write(pte_t pte)      { return !(pte_val(pte) & _PAGE_RONLY); }
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_special(pte_t pte)    { return 0; }

static inline pte_t pte_wrprotect(pte_t pte)    { pte_val(pte) |= _PAGE_RONLY; 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_mkwrite(pte_t pte)  { pte_val(pte) &= ~_PAGE_RONLY; 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_mknocache(pte_t pte)
{
    pte_val(pte) = (pte_val(pte) & _CACHEMASK040) | m68k_pgtable_cachemode;
    return pte;
}
static inline pte_t pte_mkcache(pte_t pte)
{
    pte_val(pte) = (pte_val(pte) & _CACHEMASK040) | m68k_supervisor_cachemode;
    return pte;
}
static inline pte_t pte_mkspecial(pte_t pte)    { return pte; }

#define PAGE_DIR_OFFSET(tsk,address) pgd_offset((tsk),(address))

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

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

#define swapper_pg_dir kernel_pg_dir
extern pgd_t kernel_pg_dir[128];

static inline pgd_t *pgd_offset_k(unsigned long address)
{
    return kernel_pg_dir + (address >> PGDIR_SHIFT);
}


/* Find an entry in the second-level page table.. */
static inline pmd_t *pmd_offset(pgd_t *dir, unsigned long address)
{
    return (pmd_t *)__pgd_page(*dir) + ((address >> PMD_SHIFT) & (PTRS_PER_PMD-1));
}

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

#define pte_offset_map(pmdp,address) ((pte_t *)__pmd_page(*pmdp) + (((address) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1)))
#define pte_unmap(pte)      ((void)0)

/*
 * Allocate and free page tables. The xxx_kernel() versions are
 * used to allocate a kernel page table - this turns on ASN bits
 * if any.
 */

/* Prior to calling these routines, the page should have been flushed
 * from both the cache and ATC, or the CPU might not notice that the
 * cache setting for the page has been changed. -jskov
 */
static inline void nocache_page(void *vaddr)
{
    unsigned long addr = (unsigned long)vaddr;

    if (CPU_IS_040_OR_060) {
        pgd_t *dir;
        pmd_t *pmdp;
        pte_t *ptep;

        dir = pgd_offset_k(addr);
        pmdp = pmd_offset(dir, addr);
        ptep = pte_offset_kernel(pmdp, addr);
        *ptep = pte_mknocache(*ptep);
    }
}

static inline void cache_page(void *vaddr)
{
    unsigned long addr = (unsigned long)vaddr;

    if (CPU_IS_040_OR_060) {
        pgd_t *dir;
        pmd_t *pmdp;
        pte_t *ptep;

        dir = pgd_offset_k(addr);
        pmdp = pmd_offset(dir, addr);
        ptep = pte_offset_kernel(pmdp, addr);
        *ptep = pte_mkcache(*ptep);
    }
}

#define PTE_FILE_MAX_BITS   28

static inline unsigned long pte_to_pgoff(pte_t pte)
{
    return pte.pte >> 4;
}

static inline pte_t pgoff_to_pte(unsigned off)
{
    pte_t pte = { (off << 4) + _PAGE_FILE };
    return pte;
}

/* Encode and de-code a swap entry (must be !pte_none(e) && !pte_present(e)) */
#define __swp_type(x)       (((x).val >> 4) & 0xff)
#define __swp_offset(x)     ((x).val >> 12)
#define __swp_entry(type, offset) ((swp_entry_t) { ((type) << 4) | ((offset) << 12) })
#define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) })
#define __swp_entry_to_pte(x)   ((pte_t) { (x).val })

#endif  /* !__ASSEMBLY__ */
#endif /* _MOTOROLA_PGTABLE_H */