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684 | jermar | 1 | /* |
2 | * Copyright (C) 2006 Jakub Jermar |
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3 | * All rights reserved. |
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4 | * |
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5 | * Redistribution and use in source and binary forms, with or without |
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6 | * modification, are permitted provided that the following conditions |
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7 | * are met: |
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8 | * |
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9 | * - Redistributions of source code must retain the above copyright |
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10 | * notice, this list of conditions and the following disclaimer. |
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11 | * - Redistributions in binary form must reproduce the above copyright |
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12 | * notice, this list of conditions and the following disclaimer in the |
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13 | * documentation and/or other materials provided with the distribution. |
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14 | * - The name of the author may not be used to endorse or promote products |
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15 | * derived from this software without specific prior written permission. |
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16 | * |
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17 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
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18 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
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19 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
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20 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
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21 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
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22 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
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23 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
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24 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
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25 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
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26 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
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27 | */ |
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28 | |||
29 | #include <genarch/mm/page_ht.h> |
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30 | #include <mm/page.h> |
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31 | #include <mm/frame.h> |
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699 | jermar | 32 | #include <mm/heap.h> |
755 | jermar | 33 | #include <mm/as.h> |
687 | jermar | 34 | #include <arch/mm/asid.h> |
684 | jermar | 35 | #include <arch/types.h> |
36 | #include <typedefs.h> |
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37 | #include <arch/asm.h> |
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746 | jermar | 38 | #include <synch/spinlock.h> |
39 | #include <arch.h> |
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699 | jermar | 40 | #include <debug.h> |
684 | jermar | 41 | |
746 | jermar | 42 | /** |
43 | * This lock protects the page hash table. Note that software must |
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44 | * be still careful about ordering of writes to ensure consistent |
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45 | * view of the page hash table for hardware helpers such as VHPT |
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46 | * walker on ia64. |
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47 | */ |
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48 | SPINLOCK_INITIALIZE(page_ht_lock); |
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49 | |||
50 | /** |
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51 | * Page hash table pointer. |
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52 | * The page hash table may be accessed only when page_ht_lock is held. |
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53 | */ |
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54 | pte_t *page_ht = NULL; |
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55 | |||
755 | jermar | 56 | static void ht_mapping_insert(as_t *as, __address page, __address frame, int flags, __address root); |
57 | static pte_t *ht_mapping_find(as_t *as, __address page, __address root); |
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684 | jermar | 58 | |
59 | page_operations_t page_ht_operations = { |
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60 | .mapping_insert = ht_mapping_insert, |
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61 | .mapping_find = ht_mapping_find |
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62 | }; |
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63 | |||
64 | /** Map page to frame using page hash table. |
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65 | * |
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66 | * Map virtual address 'page' to physical address 'frame' |
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746 | jermar | 67 | * using 'flags'. In order not to disturb hardware searching, |
68 | * new mappings are appended to the end of the collision |
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69 | * chain. |
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684 | jermar | 70 | * |
755 | jermar | 71 | * @param as Address space to which page belongs. Must be locked prior the call. |
684 | jermar | 72 | * @param page Virtual address of the page to be mapped. |
73 | * @param frame Physical address of memory frame to which the mapping is done. |
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74 | * @param flags Flags to be used for mapping. |
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699 | jermar | 75 | * @param root Ignored. |
684 | jermar | 76 | */ |
755 | jermar | 77 | void ht_mapping_insert(as_t *as, __address page, __address frame, int flags, __address root) |
684 | jermar | 78 | { |
746 | jermar | 79 | pte_t *t, *u; |
80 | ipl_t ipl; |
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699 | jermar | 81 | |
746 | jermar | 82 | ipl = interrupts_disable(); |
83 | spinlock_lock(&page_ht_lock); |
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755 | jermar | 84 | |
85 | t = HT_HASH(page, as->asid); |
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699 | jermar | 86 | if (!HT_SLOT_EMPTY(t)) { |
746 | jermar | 87 | |
88 | /* |
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89 | * The slot is occupied. |
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90 | * Walk through the collision chain and append the mapping to its end. |
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91 | */ |
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92 | |||
93 | do { |
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94 | u = t; |
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755 | jermar | 95 | if (HT_COMPARE(page, as->asid, t)) { |
746 | jermar | 96 | /* |
97 | * Nothing to do, |
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98 | * the record is already there. |
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99 | */ |
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100 | spinlock_unlock(&page_ht_lock); |
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101 | interrupts_restore(ipl); |
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102 | return; |
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103 | } |
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104 | } while ((t = HT_GET_NEXT(t))); |
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105 | |||
106 | t = (pte_t *) malloc(sizeof(pte_t)); /* FIXME: use slab allocator for this */ |
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107 | if (!t) |
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108 | panic("could not allocate memory\n"); |
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109 | |||
110 | HT_SET_NEXT(u, t); |
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699 | jermar | 111 | } |
746 | jermar | 112 | |
755 | jermar | 113 | HT_SET_RECORD(t, page, as->asid, frame, flags); |
746 | jermar | 114 | HT_SET_NEXT(t, NULL); |
115 | |||
116 | spinlock_unlock(&page_ht_lock); |
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117 | interrupts_restore(ipl); |
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684 | jermar | 118 | } |
119 | |||
120 | /** Find mapping for virtual page in page hash table. |
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121 | * |
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122 | * Find mapping for virtual page. |
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123 | * |
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746 | jermar | 124 | * Interrupts must be disabled. |
125 | * |
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755 | jermar | 126 | * @param as Address space to wich page belongs. Must be locked prior the call. |
684 | jermar | 127 | * @param page Virtual page. |
699 | jermar | 128 | * @param root Ignored. |
684 | jermar | 129 | * |
699 | jermar | 130 | * @return NULL if there is no such mapping; requested mapping otherwise. |
684 | jermar | 131 | */ |
755 | jermar | 132 | pte_t *ht_mapping_find(as_t *as, __address page, __address root) |
684 | jermar | 133 | { |
699 | jermar | 134 | pte_t *t; |
135 | |||
746 | jermar | 136 | spinlock_lock(&page_ht_lock); |
755 | jermar | 137 | t = HT_HASH(page, as->asid); |
746 | jermar | 138 | if (!HT_SLOT_EMPTY(t)) { |
755 | jermar | 139 | while (!HT_COMPARE(page, as->asid, t) && HT_GET_NEXT(t)) |
746 | jermar | 140 | t = HT_GET_NEXT(t); |
755 | jermar | 141 | t = HT_COMPARE(page, as->asid, t) ? t : NULL; |
746 | jermar | 142 | } else { |
143 | t = NULL; |
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144 | } |
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145 | spinlock_unlock(&page_ht_lock); |
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146 | return t; |
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147 | } |
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148 | |||
149 | /** Invalidate page hash table. |
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150 | * |
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151 | * Interrupts must be disabled. |
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152 | */ |
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153 | void ht_invalidate_all(void) |
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154 | { |
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155 | pte_t *t, *u; |
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156 | int i; |
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699 | jermar | 157 | |
746 | jermar | 158 | spinlock_lock(&page_ht_lock); |
159 | for (i = 0; i < HT_ENTRIES; i++) { |
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160 | if (!HT_SLOT_EMPTY(&page_ht[i])) { |
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161 | t = HT_GET_NEXT(&page_ht[i]); |
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162 | while (t) { |
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163 | u = t; |
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164 | t = HT_GET_NEXT(t); |
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165 | free(u); /* FIXME: use slab allocator for this */ |
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166 | } |
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167 | HT_INVALIDATE_SLOT(&page_ht[i]); |
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168 | } |
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169 | } |
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170 | spinlock_unlock(&page_ht_lock); |
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684 | jermar | 171 | } |