pgtable.h

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#ifndef _ASM_M32R_PGTABLE_H
#define _ASM_M32R_PGTABLE_H

#include <asm-generic/4level-fixup.h>

#ifdef __KERNEL__
/*
 * The Linux memory management assumes a three-level page table setup. On
 * the M32R, we use that, but "fold" the mid level into the top-level page
 * table, so that we physically have the same two-level page table as the
 * M32R mmu expects.
 *
 * This file contains the functions and defines necessary to modify and use
 * the M32R page table tree.
 */

/* CAUTION!: If you change macro definitions in this file, you might have to
 * change arch/m32r/mmu.S manually.
 */

#ifndef __ASSEMBLY__

#include <linux/threads.h>
#include <linux/bitops.h>
#include <asm/processor.h>
#include <asm/addrspace.h>
#include <asm/page.h>

struct mm_struct;
struct vm_area_struct;

extern pgd_t swapper_pg_dir[1024];
extern void paging_init(void);

/*
 * ZERO_PAGE is a global shared page that is always zero: used
 * for zero-mapped memory areas etc..
 */
extern unsigned long empty_zero_page[1024];
#define ZERO_PAGE(vaddr)    (virt_to_page(empty_zero_page))

#endif /* !__ASSEMBLY__ */

#ifndef __ASSEMBLY__
#include <asm/pgtable-2level.h>
#endif

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

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

#define USER_PTRS_PER_PGD   (TASK_SIZE / PGDIR_SIZE)
#define FIRST_USER_ADDRESS  0

#ifndef __ASSEMBLY__
/* Just any arbitrary offset to the start of the vmalloc VM area: the
 * current 8MB value just means that there will be a 8MB "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. ;)
 */
#define VMALLOC_START       KSEG2
#define VMALLOC_END     KSEG3

/*
 *     M32R TLB format
 *
 *     [0]    [1:19]           [20:23]       [24:31]
 *     +-----------------------+----+-------------+
 *     |          VPN          |0000|    ASID     |
 *     +-----------------------+----+-------------+
 *     +-+---------------------+----+-+---+-+-+-+-+
 *     |0         PPN          |0000|N|AC |L|G|V| |
 *     +-+---------------------+----+-+---+-+-+-+-+
 *                                     RWX
 */

#define _PAGE_BIT_DIRTY     0   /* software: page changed */
#define _PAGE_BIT_FILE      0   /* when !present: nonlinear file
                       mapping */
#define _PAGE_BIT_PRESENT   1   /* Valid: page is valid */
#define _PAGE_BIT_GLOBAL    2   /* Global */
#define _PAGE_BIT_LARGE     3   /* Large */
#define _PAGE_BIT_EXEC      4   /* Execute */
#define _PAGE_BIT_WRITE     5   /* Write */
#define _PAGE_BIT_READ      6   /* Read */
#define _PAGE_BIT_NONCACHABLE   7   /* Non cachable */
#define _PAGE_BIT_ACCESSED  8   /* software: page referenced */
#define _PAGE_BIT_PROTNONE  9   /* software: if not present */

#define _PAGE_DIRTY     (1UL << _PAGE_BIT_DIRTY)
#define _PAGE_FILE      (1UL << _PAGE_BIT_FILE)
#define _PAGE_PRESENT       (1UL << _PAGE_BIT_PRESENT)
#define _PAGE_GLOBAL        (1UL << _PAGE_BIT_GLOBAL)
#define _PAGE_LARGE     (1UL << _PAGE_BIT_LARGE)
#define _PAGE_EXEC      (1UL << _PAGE_BIT_EXEC)
#define _PAGE_WRITE     (1UL << _PAGE_BIT_WRITE)
#define _PAGE_READ      (1UL << _PAGE_BIT_READ)
#define _PAGE_NONCACHABLE   (1UL << _PAGE_BIT_NONCACHABLE)
#define _PAGE_ACCESSED      (1UL << _PAGE_BIT_ACCESSED)
#define _PAGE_PROTNONE      (1UL << _PAGE_BIT_PROTNONE)

#define _PAGE_TABLE \
    ( _PAGE_PRESENT | _PAGE_WRITE | _PAGE_READ | _PAGE_ACCESSED \
    | _PAGE_DIRTY )
#define _KERNPG_TABLE   \
    ( _PAGE_PRESENT | _PAGE_WRITE | _PAGE_READ | _PAGE_ACCESSED \
    | _PAGE_DIRTY )
#define _PAGE_CHG_MASK  \
    ( PTE_MASK | _PAGE_ACCESSED | _PAGE_DIRTY )

#ifdef CONFIG_MMU
#define PAGE_NONE   \
    __pgprot(_PAGE_PROTNONE | _PAGE_ACCESSED)
#define PAGE_SHARED \
    __pgprot(_PAGE_PRESENT | _PAGE_WRITE | _PAGE_READ | _PAGE_ACCESSED)
#define PAGE_SHARED_EXEC \
    __pgprot(_PAGE_PRESENT | _PAGE_EXEC | _PAGE_WRITE | _PAGE_READ \
        | _PAGE_ACCESSED)
#define PAGE_COPY   \
    __pgprot(_PAGE_PRESENT | _PAGE_READ | _PAGE_ACCESSED)
#define PAGE_COPY_EXEC  \
    __pgprot(_PAGE_PRESENT | _PAGE_EXEC | _PAGE_READ | _PAGE_ACCESSED)
#define PAGE_READONLY   \
    __pgprot(_PAGE_PRESENT | _PAGE_READ | _PAGE_ACCESSED)
#define PAGE_READONLY_EXEC \
    __pgprot(_PAGE_PRESENT | _PAGE_EXEC | _PAGE_READ | _PAGE_ACCESSED)

#define __PAGE_KERNEL   \
    ( _PAGE_PRESENT | _PAGE_EXEC | _PAGE_WRITE | _PAGE_READ | _PAGE_DIRTY \
    | _PAGE_ACCESSED )
#define __PAGE_KERNEL_RO    ( __PAGE_KERNEL & ~_PAGE_WRITE )
#define __PAGE_KERNEL_NOCACHE   ( __PAGE_KERNEL | _PAGE_NONCACHABLE)

#define MAKE_GLOBAL(x)  __pgprot((x) | _PAGE_GLOBAL)

#define PAGE_KERNEL     MAKE_GLOBAL(__PAGE_KERNEL)
#define PAGE_KERNEL_RO      MAKE_GLOBAL(__PAGE_KERNEL_RO)
#define PAGE_KERNEL_NOCACHE MAKE_GLOBAL(__PAGE_KERNEL_NOCACHE)

#else
#define PAGE_NONE       __pgprot(0)
#define PAGE_SHARED     __pgprot(0)
#define PAGE_SHARED_EXEC    __pgprot(0)
#define PAGE_COPY       __pgprot(0)
#define PAGE_COPY_EXEC      __pgprot(0)
#define PAGE_READONLY       __pgprot(0)
#define PAGE_READONLY_EXEC  __pgprot(0)

#define PAGE_KERNEL     __pgprot(0)
#define PAGE_KERNEL_RO      __pgprot(0)
#define PAGE_KERNEL_NOCACHE __pgprot(0)
#endif /* CONFIG_MMU */

    /* xwr */
#define __P000  PAGE_NONE
#define __P001  PAGE_READONLY
#define __P010  PAGE_COPY
#define __P011  PAGE_COPY
#define __P100  PAGE_READONLY_EXEC
#define __P101  PAGE_READONLY_EXEC
#define __P110  PAGE_COPY_EXEC
#define __P111  PAGE_COPY_EXEC

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

/* page table for 0-4MB for everybody */

#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 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 pmd_bad(x)  ((pmd_val(x) & ~PAGE_MASK) != _KERNPG_TABLE)

#define pages_to_mb(x)  ((x) >> (20 - PAGE_SHIFT))

/*
 * The following only work if pte_present() is true.
 * Undefined behaviour if not..
 */
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_write(pte_t pte)
{
    return pte_val(pte) & _PAGE_WRITE;
}

/*
 * The following only works if pte_present() is not true.
 */
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_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_wrprotect(pte_t pte)
{
    pte_val(pte) &= ~_PAGE_WRITE;
    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_mkwrite(pte_t pte)
{
    pte_val(pte) |= _PAGE_WRITE;
    return pte;
}

static inline pte_t pte_mkspecial(pte_t pte)
{
    return pte;
}

static inline  int ptep_test_and_clear_young(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep)
{
    return test_and_clear_bit(_PAGE_BIT_ACCESSED, ptep);
}

static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
{
    clear_bit(_PAGE_BIT_WRITE, ptep);
}

/*
 * Macro and implementation to make a page protection as uncachable.
 */
static inline pgprot_t pgprot_noncached(pgprot_t _prot)
{
    unsigned long prot = pgprot_val(_prot);

    prot |= _PAGE_NONCACHABLE;
    return __pgprot(prot);
}

#define pgprot_writecombine(prot) pgprot_noncached(prot)

/*
 * 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)
{
    set_pte(&pte, __pte((pte_val(pte) & _PAGE_CHG_MASK) \
        | pgprot_val(newprot)));

    return pte;
}

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

#define pmd_page_vaddr(pmd) \
    ((unsigned long) __va(pmd_val(pmd) & PAGE_MASK))

#ifndef CONFIG_DISCONTIGMEM
#define pmd_page(pmd)   (mem_map + ((pmd_val(pmd) >> PAGE_SHIFT) - PFN_BASE))
#endif /* !CONFIG_DISCONTIGMEM */

/* to find an entry in a page-table-directory. */
#define pgd_index(address)  \
    (((address) >> PGDIR_SHIFT) & (PTRS_PER_PGD - 1))

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

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

#define pmd_index(address)  \
    (((address) >> PMD_SHIFT) & (PTRS_PER_PMD - 1))

#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))
#define pte_offset_map(dir, address)    \
    ((pte_t *)page_address(pmd_page(*(dir))) + pte_index(address))
#define pte_unmap(pte)      do { } while (0)

/* Encode and de-code a swap entry */
#define __swp_type(x)           (((x).val >> 2) & 0x1f)
#define __swp_offset(x)         ((x).val >> 10)
#define __swp_entry(type, offset)   \
    ((swp_entry_t) { ((type) << 2) | ((offset) << 10) })
#define __pte_to_swp_entry(pte)     ((swp_entry_t) { pte_val(pte) })
#define __swp_entry_to_pte(x)       ((pte_t) { (x).val })

#endif /* !__ASSEMBLY__ */

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

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

#define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
#define __HAVE_ARCH_PTEP_GET_AND_CLEAR
#define __HAVE_ARCH_PTEP_SET_WRPROTECT
#define __HAVE_ARCH_PTE_SAME
#include <asm-generic/pgtable.h>

#endif /* __KERNEL__ */

#endif /* _ASM_M32R_PGTABLE_H */