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  1. /*
  2.  * Copyright (C) 2001-2004 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. #include <mm/page.h>
  30. #include <mm/frame.h>
  31. #include <arch/mm/page.h>
  32. #include <arch/types.h>
  33. #include <typedefs.h>
  34. #include <arch/asm.h>
  35. #include <memstr.h>
  36.  
  37. void page_init(void)
  38. {
  39.     page_arch_init();
  40.     page_mapping_insert(0x0, 0x0, PAGE_NOT_PRESENT, 0);
  41. }
  42.  
  43. /** Map memory structure
  44.  *
  45.  * Identity-map memory structure
  46.  * considering possible crossings
  47.  * of page boundaries.
  48.  *
  49.  * @param s Address of the structure.
  50.  * @param size Size of the structure.
  51.  */
  52. void map_structure(__address s, size_t size)
  53. {
  54.     int i, cnt, length;
  55.  
  56.     length = size + (s - (s & ~(PAGE_SIZE-1)));
  57.     cnt = length/PAGE_SIZE + (length%PAGE_SIZE>0);
  58.  
  59.     for (i = 0; i < cnt; i++)
  60.         page_mapping_insert(s + i*PAGE_SIZE, s + i*PAGE_SIZE, PAGE_NOT_CACHEABLE, 0);
  61.  
  62. }
  63.  
  64. /** Map page to frame
  65.  *
  66.  * Map virtual address 'page' to physical address 'frame'
  67.  * using 'flags'. Allocate and setup any missing page tables.
  68.  *
  69.  * @param page Virtual address of the page to be mapped.
  70.  * @param frame Physical address of memory frame to which the mapping is done.
  71.  * @param flags Flags to be used for mapping.
  72.  * @param root Explicit PTL0 address.
  73.  */
  74. void page_mapping_insert(__address page, __address frame, int flags, __address root)
  75. {
  76.     pte_t *ptl0, *ptl1, *ptl2, *ptl3;
  77.     __address newpt;
  78.  
  79.     ptl0 = (pte_t *) PA2KA(root ? root : (__address) GET_PTL0_ADDRESS());
  80.  
  81.     if (GET_PTL1_FLAGS(ptl0, PTL0_INDEX(page)) & PAGE_NOT_PRESENT) {
  82.         newpt = frame_alloc(FRAME_KA);
  83.         memsetb(newpt, PAGE_SIZE, 0);
  84.         SET_PTL1_ADDRESS(ptl0, PTL0_INDEX(page), KA2PA(newpt));
  85.         SET_PTL1_FLAGS(ptl0, PTL0_INDEX(page), PAGE_PRESENT | PAGE_USER | PAGE_EXEC);
  86.     }
  87.  
  88.     ptl1 = (pte_t *) PA2KA(GET_PTL1_ADDRESS(ptl0, PTL0_INDEX(page)));
  89.  
  90.     if (GET_PTL2_FLAGS(ptl1, PTL1_INDEX(page)) & PAGE_NOT_PRESENT) {
  91.         newpt = frame_alloc(FRAME_KA);
  92.         memsetb(newpt, PAGE_SIZE, 0);
  93.         SET_PTL2_ADDRESS(ptl1, PTL1_INDEX(page), KA2PA(newpt));
  94.         SET_PTL2_FLAGS(ptl1, PTL1_INDEX(page), PAGE_PRESENT | PAGE_USER | PAGE_EXEC);
  95.     }
  96.  
  97.     ptl2 = (pte_t *) PA2KA(GET_PTL2_ADDRESS(ptl1, PTL1_INDEX(page)));
  98.  
  99.     if (GET_PTL3_FLAGS(ptl2, PTL2_INDEX(page)) & PAGE_NOT_PRESENT) {
  100.         newpt = frame_alloc(FRAME_KA);
  101.         memsetb(newpt, PAGE_SIZE, 0);
  102.         SET_PTL3_ADDRESS(ptl2, PTL2_INDEX(page), KA2PA(newpt));
  103.         SET_PTL3_FLAGS(ptl2, PTL2_INDEX(page), PAGE_PRESENT | PAGE_USER | PAGE_EXEC);
  104.     }
  105.  
  106.     ptl3 = (pte_t *) PA2KA(GET_PTL3_ADDRESS(ptl2, PTL2_INDEX(page)));
  107.  
  108.     SET_FRAME_ADDRESS(ptl3, PTL3_INDEX(page), frame);
  109.     SET_FRAME_FLAGS(ptl3, PTL3_INDEX(page), flags);
  110. }
  111.  
  112. /** Find mapping for virtual page
  113.  *
  114.  * Find mapping for virtual page.
  115.  *
  116.  * @param page Virtual page.
  117.  * @param root PTL0 address if non-zero.
  118.  *
  119.  * @return NULL if there is no such mapping; entry from PTL3 describing the mapping otherwise.
  120.  */
  121. pte_t *page_mapping_find(__address page, __address root)
  122. {
  123.     pte_t *ptl0, *ptl1, *ptl2, *ptl3;
  124.  
  125.     ptl0 = (pte_t *) PA2KA(root ? root : (__address) GET_PTL0_ADDRESS());
  126.  
  127.     if (GET_PTL1_FLAGS(ptl0, PTL0_INDEX(page)) & PAGE_NOT_PRESENT)
  128.         return NULL;
  129.  
  130.     ptl1 = (pte_t *) PA2KA(GET_PTL1_ADDRESS(ptl0, PTL0_INDEX(page)));
  131.  
  132.     if (GET_PTL2_FLAGS(ptl1, PTL1_INDEX(page)) & PAGE_NOT_PRESENT)
  133.         return NULL;
  134.  
  135.     ptl2 = (pte_t *) PA2KA(GET_PTL2_ADDRESS(ptl1, PTL1_INDEX(page)));
  136.  
  137.     if (GET_PTL3_FLAGS(ptl2, PTL2_INDEX(page)) & PAGE_NOT_PRESENT)
  138.         return NULL;
  139.  
  140.     ptl3 = (pte_t *) PA2KA(GET_PTL3_ADDRESS(ptl2, PTL2_INDEX(page)));
  141.  
  142.     return &ptl3[PTL3_INDEX(page)];
  143. }
  144.