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/*

 * Copyright (c) 2005 Ondrej Palkovsky

 * 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 amd64mm

 * @{

 */

/** @file

 */

/** Paging on AMD64

 *

 * The space is divided in positive numbers - userspace and

 * negative numbers - kernel space. The 'negative' space starting

 * with 0xffff800000000000 and ending with 0xffffffff80000000

 * (-2GB) is identically mapped physical memory. The area

 * (0xffffffff80000000 ... 0xffffffffffffffff is again identically

 * mapped first 2GB.

 *

 * ATTENTION - PA2KA(KA2PA(x)) != x if 'x' is in kernel

 */

#ifndef KERN_amd64_PAGE_H_

#define KERN_amd64_PAGE_H_

#include <arch/mm/frame.h>

#define PAGE_WIDTH  FRAME_WIDTH

#define PAGE_SIZE   FRAME_SIZE

#define PAGE_COLOR_BITS 0           /* dummy */

#ifdef KERNEL

#ifndef __ASM__

#   include <mm/mm.h>

#   include <arch/types.h>

#   include <arch/interrupt.h>

static inline uintptr_t ka2pa(uintptr_t x)

{

    if (x > 0xffffffff80000000)

        return x - 0xffffffff80000000;

    else

        return x - 0xffff800000000000;

}

#   define KA2PA(x)     ka2pa((uintptr_t) x)

#   define PA2KA_CODE(x)    (((uintptr_t) (x)) + 0xffffffff80000000)

#   define PA2KA(x)     (((uintptr_t) (x)) + 0xffff800000000000)

#else

#   define KA2PA(x)     ((x) - 0xffffffff80000000)

#   define PA2KA(x)     ((x) + 0xffffffff80000000)

#endif

/* Number of entries in each level. */

#define PTL0_ENTRIES_ARCH   512

#define PTL1_ENTRIES_ARCH   512

#define PTL2_ENTRIES_ARCH   512

#define PTL3_ENTRIES_ARCH   512

/* Page table sizes for each level. */

#define PTL0_SIZE_ARCH      ONE_FRAME

#define PTL1_SIZE_ARCH      ONE_FRAME

#define PTL2_SIZE_ARCH      ONE_FRAME

#define PTL3_SIZE_ARCH      ONE_FRAME

/* Macros calculating indices into page tables in each level. */

#define PTL0_INDEX_ARCH(vaddr)  (((vaddr) >> 39) & 0x1ff)

#define PTL1_INDEX_ARCH(vaddr)  (((vaddr) >> 30) & 0x1ff)

#define PTL2_INDEX_ARCH(vaddr)  (((vaddr) >> 21) & 0x1ff)

#define PTL3_INDEX_ARCH(vaddr)  (((vaddr) >> 12) & 0x1ff)

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

#define GET_PTL1_ADDRESS_ARCH(ptl0, i) \

    ((pte_t *) ((((uint64_t) ((pte_t *) (ptl0))[(i)].addr_12_31) << 12) | \

        (((uint64_t) ((pte_t *) (ptl0))[(i)].addr_32_51) << 32)))

#define GET_PTL2_ADDRESS_ARCH(ptl1, i) \

    ((pte_t *) ((((uint64_t) ((pte_t *) (ptl1))[(i)].addr_12_31) << 12) | \

        (((uint64_t) ((pte_t *) (ptl1))[(i)].addr_32_51) << 32)))

#define GET_PTL3_ADDRESS_ARCH(ptl2, i) \

    ((pte_t *) ((((uint64_t) ((pte_t *) (ptl2))[(i)].addr_12_31) << 12) | \

        (((uint64_t) ((pte_t *) (ptl2))[(i)].addr_32_51) << 32)))

#define GET_FRAME_ADDRESS_ARCH(ptl3, i) \

    ((uintptr_t *) \

        ((((uint64_t) ((pte_t *) (ptl3))[(i)].addr_12_31) << 12) | \

        (((uint64_t) ((pte_t *) (ptl3))[(i)].addr_32_51) << 32)))

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

#define SET_PTL0_ADDRESS_ARCH(ptl0) \

    (write_cr3((uintptr_t) (ptl0)))

#define SET_PTL1_ADDRESS_ARCH(ptl0, i, a) \

    set_pt_addr((pte_t *) (ptl0), (index_t) (i), a)

#define SET_PTL2_ADDRESS_ARCH(ptl1, i, a) \

    set_pt_addr((pte_t *) (ptl1), (index_t) (i), a)

#define SET_PTL3_ADDRESS_ARCH(ptl2, i, a) \

    set_pt_addr((pte_t *) (ptl2), (index_t) (i), a)

#define SET_FRAME_ADDRESS_ARCH(ptl3, i, a) \

    set_pt_addr((pte_t *) (ptl3), (index_t) (i), a)

/* 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) \

    get_pt_flags((pte_t *) (ptl1), (index_t) (i))

#define GET_PTL3_FLAGS_ARCH(ptl2, i) \

    get_pt_flags((pte_t *) (ptl2), (index_t) (i))

#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) \

    set_pt_flags((pte_t *) (ptl1), (index_t) (i), (x))

#define SET_PTL3_FLAGS_ARCH(ptl2, i, x) \

    set_pt_flags((pte_t *) (ptl2), (index_t) (i), (x))

#define SET_FRAME_FLAGS_ARCH(ptl3, i, x) \

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

/* Macros for querying the last-level PTE entries. */

#define PTE_VALID_ARCH(p) \

    (*((uint64_t *) (p)) != 0)

#define PTE_PRESENT_ARCH(p) \

    ((p)->present != 0)

#define PTE_GET_FRAME_ARCH(p) \

    ((((uintptr_t) (p)->addr_12_31) << 12) | \

        ((uintptr_t) (p)->addr_32_51 << 32))

#define PTE_WRITABLE_ARCH(p) \

    ((p)->writeable != 0)

#define PTE_EXECUTABLE_ARCH(p) \

    ((p)->no_execute == 0)

#ifndef __ASM__

/* Page fault error codes. */

/** When bit on this position is 0, the page fault was caused by a not-present

 * page.

 */

#define PFERR_CODE_P            (1 << 0)  

/** When bit on this position is 1, the page fault was caused by a write. */

#define PFERR_CODE_RW           (1 << 1)

/** When bit on this position is 1, the page fault was caused in user mode. */

#define PFERR_CODE_US           (1 << 2)

/** When bit on this position is 1, a reserved bit was set in page directory. */

#define PFERR_CODE_RSVD         (1 << 3)

/** When bit on this position os 1, the page fault was caused during instruction

 * fecth.

 */

#define PFERR_CODE_ID       (1 << 4)

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

{

    pte_t *p = &pt[i];

    return ((!p->page_cache_disable) << PAGE_CACHEABLE_SHIFT |

        (!p->present) << PAGE_PRESENT_SHIFT |

        p->uaccessible << PAGE_USER_SHIFT |

        1 << PAGE_READ_SHIFT |

        p->writeable << PAGE_WRITE_SHIFT |

        (!p->no_execute) << PAGE_EXEC_SHIFT |

        p->global << PAGE_GLOBAL_SHIFT);

}

static inline void set_pt_addr(pte_t *pt, index_t i, uintptr_t a)

{

    pte_t *p = &pt[i];

    p->addr_12_31 = (a >> 12) & 0xfffff;

    p->addr_32_51 = a >> 32;

}

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

{

    pte_t *p = &pt[i];

    p->page_cache_disable = !(flags & PAGE_CACHEABLE);

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

    p->uaccessible = (flags & PAGE_USER) != 0;

    p->writeable = (flags & PAGE_WRITE) != 0;

    p->no_execute = (flags & PAGE_EXEC) == 0;

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

    /*

     * Ensure that there is at least one bit set even if the present bit is cleared.

     */

    p->soft_valid = 1;

}

extern void page_arch_init(void);

extern void page_fault(int n, istate_t *istate);

#endif /* __ASM__ */

#endif /* KERNEL */

#endif

/** @}

 */