source: mainline/kernel/arch/amd64/include/mm/page.h@ 1ba41c5

/*
 * 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/page.h>
#  include <arch/types.h>
#endif

#ifndef __ASM__
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

#define PTL0_ENTRIES_ARCH       512
#define PTL1_ENTRIES_ARCH       512
#define PTL2_ENTRIES_ARCH       512
#define PTL3_ENTRIES_ARCH       512

#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)

#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 )))

#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)

#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))

#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))

#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)

/** Page Table Entry. */
struct page_specifier {
        unsigned present : 1;
        unsigned writeable : 1;
        unsigned uaccessible : 1;
        unsigned page_write_through : 1;
        unsigned page_cache_disable : 1;
        unsigned accessed : 1;
        unsigned dirty : 1;
        unsigned unused: 1;
        unsigned global : 1;
        unsigned soft_valid : 1;                /**< Valid content even if present bit is cleared. */
        unsigned avl : 2;
        unsigned addr_12_31 : 30;
        unsigned addr_32_51 : 21;
        unsigned no_execute : 1;
} __attribute__ ((packed));

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

/** @}
 */