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  1. /*
  2.  * Copyright (C) 2006 Jakub Jermar
  3.  * All rights reserved.
  4.  *
  5.  * Redistribution and use in source and binary forms, with or without
  6.  * modification, are permitted provided that the following conditions
  7.  * are met:
  8.  *
  9.  * - Redistributions of source code must retain the above copyright
  10.  *   notice, this list of conditions and the following disclaimer.
  11.  * - Redistributions in binary form must reproduce the above copyright
  12.  *   notice, this list of conditions and the following disclaimer in the
  13.  *   documentation and/or other materials provided with the distribution.
  14.  * - The name of the author may not be used to endorse or promote products
  15.  *   derived from this software without specific prior written permission.
  16.  *
  17.  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  18.  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  19.  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  20.  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  21.  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  22.  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  23.  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  24.  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25.  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  26.  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27.  */
  28.  
  29. /**
  30.  * @file    backend_elf.c
  31.  * @brief   Backend for address space areas backed by continuous physical memory.
  32.  */
  33.  
  34. #include <debug.h>
  35. #include <arch/types.h>
  36. #include <typedefs.h>
  37. #include <mm/as.h>
  38. #include <mm/frame.h>
  39. #include <mm/slab.h>
  40. #include <memstr.h>
  41. #include <macros.h>
  42. #include <arch.h>
  43. #include <align.h>
  44.  
  45. static int phys_page_fault(as_area_t *area, __address addr, pf_access_t access);
  46. static void phys_share(as_area_t *area);
  47.  
  48. mem_backend_t phys_backend = {
  49.     .page_fault = phys_page_fault,
  50.     .frame_free = NULL,
  51.     .share = phys_share
  52. };
  53.  
  54. /** Service a page fault in the address space area backed by physical memory.
  55.  *
  56.  * The address space area and page tables must be already locked.
  57.  *
  58.  * @param area Pointer to the address space area.
  59.  * @param addr Faulting virtual address.
  60.  * @param access Access mode that caused the fault (i.e. read/write/exec).
  61.  *
  62.  * @return AS_PF_FAULT on failure (i.e. page fault) or AS_PF_OK on success (i.e. serviced).
  63.  */
  64. int phys_page_fault(as_area_t *area, __address addr, pf_access_t access)
  65. {
  66.     __address base = (__address) area->backend_data.d1;
  67.     count_t frames = (count_t) area->backend_data.d2;
  68.  
  69.     if (!as_area_check_access(area, access))
  70.         return AS_PF_FAULT;
  71.  
  72.     ASSERT(addr - area->base < frames * FRAME_SIZE);
  73.     page_mapping_insert(AS, addr, base + (addr - area->base), as_area_get_flags(area));
  74.         if (!used_space_insert(area, ALIGN_DOWN(addr, PAGE_SIZE), 1))
  75.                 panic("Could not insert used space.\n");
  76.  
  77.     return AS_PF_OK;
  78. }
  79.  
  80. /** Share address space area backed by physical memory.
  81.  *
  82.  * Do actually nothing as sharing of address space areas
  83.  * that are backed up by physical memory is very easy.
  84.  * Note that the function must be defined so that
  85.  * as_area_share() will succeed.
  86.  */
  87. void phys_share(as_area_t *area)
  88. {
  89. }
  90.