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/*

 * Copyright (c) 2003-2004 Jakub Jermar

 * All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 *

 * - Redistributions of source code must retain the above copyright

 *   notice, this list of conditions and the following disclaimer.

 * - Redistributions in binary form must reproduce the above copyright

 *   notice, this list of conditions and the following disclaimer in the

 *   documentation and/or other materials provided with the distribution.

 * - The name of the author may not be used to endorse or promote products

 *   derived from this software without specific prior written permission.

 *

 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR

 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES

 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.

 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,

 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT

 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,

 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY

 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF

 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 */

/** @addtogroup mips32mm   

 * @{

 */

/** @file

 */

#ifndef KERN_mips32_PAGE_H_

#define KERN_mips32_PAGE_H_

#include <arch/mm/frame.h>

#define PAGE_WIDTH  FRAME_WIDTH

#define PAGE_SIZE   FRAME_SIZE

#define PAGE_COLOR_BITS 0           /* dummy */

#ifndef __ASM__

#   define KA2PA(x) (((uintptr_t) (x)) - 0x80000000)

#   define PA2KA(x) (((uintptr_t) (x)) + 0x80000000)

#else

#   define KA2PA(x) ((x) - 0x80000000)

#   define PA2KA(x) ((x) + 0x80000000)

#endif

#ifdef KERNEL

/*

 * Implementation of generic 4-level page table interface.

 *

 * Page table layout:

 * - 32-bit virtual addresses

 * - Offset is 14 bits => pages are 16K long

 * - PTE's use similar format as CP0 EntryLo[01] registers => PTE is therefore

 *   4 bytes long

 * - PTE's replace EntryLo v (valid) bit with p (present) bit

 * - PTE's use only one bit to distinguish between cacheable and uncacheable

 *   mappings

 * - PTE's define soft_valid field to ensure there is at least one 1 bit even if

 *   the p bit is cleared

 * - PTE's make use of CP0 EntryLo's two-bit reserved field for bit W (writable)

 *   and bit A (accessed)

 * - PTL0 has 64 entries (6 bits)

 * - PTL1 is not used

 * - PTL2 is not used

 * - PTL3 has 4096 entries (12 bits)

 */

/* Macros describing number of entries in each level. */

#define PTL0_ENTRIES_ARCH   64

#define PTL1_ENTRIES_ARCH   0

#define PTL2_ENTRIES_ARCH   0

#define PTL3_ENTRIES_ARCH   4096

/* Macros describing size of page tables in each level. */

#define PTL0_SIZE_ARCH      ONE_FRAME

#define PTL1_SIZE_ARCH      0

#define PTL2_SIZE_ARCH      0

#define PTL3_SIZE_ARCH      ONE_FRAME

/* Macros calculating entry indices for each level. */

#define PTL0_INDEX_ARCH(vaddr)  ((vaddr) >> 26) 

#define PTL1_INDEX_ARCH(vaddr)  0

#define PTL2_INDEX_ARCH(vaddr)  0

#define PTL3_INDEX_ARCH(vaddr)  (((vaddr) >> 14) & 0xfff)

/* Set accessor for PTL0 address. */

#define SET_PTL0_ADDRESS_ARCH(ptl0)

/* Get PTE address accessors for each level. */

#define GET_PTL1_ADDRESS_ARCH(ptl0, i) \

    (((pte_t *) (ptl0))[(i)].pfn << 12)

#define GET_PTL2_ADDRESS_ARCH(ptl1, i) \

    (ptl1)

#define GET_PTL3_ADDRESS_ARCH(ptl2, i) \

    (ptl2)

#define GET_FRAME_ADDRESS_ARCH(ptl3, i) \

    (((pte_t *) (ptl3))[(i)].pfn << 12)

/* Set PTE address accessors for each level. */

#define SET_PTL1_ADDRESS_ARCH(ptl0, i, a) \

    (((pte_t *) (ptl0))[(i)].pfn = (a) >> 12)

#define SET_PTL2_ADDRESS_ARCH(ptl1, i, a)

#define SET_PTL3_ADDRESS_ARCH(ptl2, i, a)

#define SET_FRAME_ADDRESS_ARCH(ptl3, i, a) \

    (((pte_t *) (ptl3))[(i)].pfn = (a) >> 12)

/* Get PTE flags accessors for each level. */

#define GET_PTL1_FLAGS_ARCH(ptl0, i) \

    get_pt_flags((pte_t *) (ptl0), (index_t) (i))

#define GET_PTL2_FLAGS_ARCH(ptl1, i) \

    PAGE_PRESENT

#define GET_PTL3_FLAGS_ARCH(ptl2, i) \

    PAGE_PRESENT

#define GET_FRAME_FLAGS_ARCH(ptl3, i) \

    get_pt_flags((pte_t *) (ptl3), (index_t) (i))

/* Set PTE flags accessors for each level. */

#define SET_PTL1_FLAGS_ARCH(ptl0, i, x) \

    set_pt_flags((pte_t *) (ptl0), (index_t) (i), (x))

#define SET_PTL2_FLAGS_ARCH(ptl1, i, x)

#define SET_PTL3_FLAGS_ARCH(ptl2, i, x)

#define SET_FRAME_FLAGS_ARCH(ptl3, i, x) \

    set_pt_flags((pte_t *) (ptl3), (index_t) (i), (x))

/* Last-level info macros. */

#define PTE_VALID_ARCH(pte)         (*((uint32_t *) (pte)) != 0)

#define PTE_PRESENT_ARCH(pte)           ((pte)->p != 0)

#define PTE_GET_FRAME_ARCH(pte)         ((pte)->pfn << 12)

#define PTE_WRITABLE_ARCH(pte)          ((pte)->w != 0)

#define PTE_EXECUTABLE_ARCH(pte)        1

#ifndef __ASM__

#include <mm/mm.h>

#include <arch/exception.h>

static inline int get_pt_flags(pte_t *pt, index_t i)

{

    pte_t *p = &pt[i];

    return ((p->cacheable << PAGE_CACHEABLE_SHIFT) |

        ((!p->p) << PAGE_PRESENT_SHIFT) |

        (1 << PAGE_USER_SHIFT) |

        (1 << PAGE_READ_SHIFT) |

        ((p->w) << PAGE_WRITE_SHIFT) |

        (1 << PAGE_EXEC_SHIFT) |

        (p->g << PAGE_GLOBAL_SHIFT));

}

static inline void set_pt_flags(pte_t *pt, index_t i, int flags)

{

    pte_t *p = &pt[i];

    p->cacheable = (flags & PAGE_CACHEABLE) != 0;

    p->p = !(flags & PAGE_NOT_PRESENT);

    p->g = (flags & PAGE_GLOBAL) != 0;

    p->w = (flags & PAGE_WRITE) != 0;

    /*

     * Ensure that valid entries have at least one bit set.

     */

    p->soft_valid = 1;

}

extern void page_arch_init(void);

#endif /* __ASM__ */

#endif /* KERNEL */

#endif

/** @}

 */