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377 | jermar | 1 | /* |
2 | * Copyright (C) 2005 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 | |||
1702 | cejka | 29 | /** @addtogroup genericmm |
30 | * @{ |
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31 | */ |
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32 | |||
1248 | jermar | 33 | /** |
1702 | cejka | 34 | * @file |
1248 | jermar | 35 | * @brief Buddy allocator framework. |
36 | * |
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37 | * This file contains buddy system allocator framework. |
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38 | * Specialized functions are needed for this abstract framework |
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39 | * to be useful. |
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40 | */ |
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41 | |||
377 | jermar | 42 | #include <mm/buddy.h> |
43 | #include <mm/frame.h> |
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44 | #include <arch/types.h> |
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45 | #include <typedefs.h> |
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788 | jermar | 46 | #include <adt/list.h> |
377 | jermar | 47 | #include <debug.h> |
533 | bondari | 48 | #include <print.h> |
377 | jermar | 49 | |
814 | palkovsky | 50 | /** Return size needed for the buddy configuration data */ |
51 | size_t buddy_conf_size(int max_order) |
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52 | { |
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53 | return sizeof(buddy_system_t) + (max_order + 1) * sizeof(link_t); |
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54 | } |
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55 | |||
56 | |||
377 | jermar | 57 | /** Create buddy system |
58 | * |
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59 | * Allocate memory for and initialize new buddy system. |
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60 | * |
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1229 | jermar | 61 | * @param b Preallocated buddy system control data. |
377 | jermar | 62 | * @param max_order The biggest allocable size will be 2^max_order. |
63 | * @param op Operations for new buddy system. |
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490 | jermar | 64 | * @param data Pointer to be used by implementation. |
377 | jermar | 65 | * |
66 | * @return New buddy system. |
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67 | */ |
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814 | palkovsky | 68 | void buddy_system_create(buddy_system_t *b, |
69 | __u8 max_order, |
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70 | buddy_system_operations_t *op, |
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71 | void *data) |
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377 | jermar | 72 | { |
73 | int i; |
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74 | |||
378 | jermar | 75 | ASSERT(max_order < BUDDY_SYSTEM_INNER_BLOCK); |
76 | |||
377 | jermar | 77 | ASSERT(op->find_buddy); |
78 | ASSERT(op->set_order); |
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79 | ASSERT(op->get_order); |
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80 | ASSERT(op->bisect); |
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81 | ASSERT(op->coalesce); |
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533 | bondari | 82 | ASSERT(op->mark_busy); |
377 | jermar | 83 | |
84 | /* |
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814 | palkovsky | 85 | * Use memory after our own structure |
86 | */ |
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87 | b->order = (link_t *) (&b[1]); |
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377 | jermar | 88 | |
814 | palkovsky | 89 | for (i = 0; i <= max_order; i++) |
90 | list_initialize(&b->order[i]); |
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91 | |||
92 | b->max_order = max_order; |
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93 | b->op = op; |
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94 | b->data = data; |
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377 | jermar | 95 | } |
96 | |||
533 | bondari | 97 | /** Check if buddy system can allocate block |
98 | * |
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99 | * @param b Buddy system pointer |
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100 | * @param i Size of the block (2^i) |
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101 | * |
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102 | * @return True if block can be allocated |
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103 | */ |
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104 | bool buddy_system_can_alloc(buddy_system_t *b, __u8 i) { |
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105 | __u8 k; |
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106 | |||
735 | bondari | 107 | /* |
108 | * If requested block is greater then maximal block |
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109 | * we know immediatly that we cannot satisfy the request. |
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110 | */ |
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111 | if (i > b->max_order) return false; |
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112 | |||
113 | /* |
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114 | * Check if any bigger or equal order has free elements |
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115 | */ |
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116 | for (k=i; k <= b->max_order; k++) { |
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533 | bondari | 117 | if (!list_empty(&b->order[k])) { |
118 | return true; |
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119 | } |
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120 | } |
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121 | |||
122 | return false; |
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123 | |||
124 | } |
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125 | |||
814 | palkovsky | 126 | /** Allocate PARTICULAR block from buddy system |
127 | * |
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128 | * @ return Block of data or NULL if no such block was found |
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129 | */ |
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130 | link_t *buddy_system_alloc_block(buddy_system_t *b, link_t *block) |
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131 | { |
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132 | link_t *left,*right, *tmp; |
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133 | __u8 order; |
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134 | |||
135 | left = b->op->find_block(b, block, BUDDY_SYSTEM_INNER_BLOCK); |
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136 | ASSERT(left); |
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137 | list_remove(left); |
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138 | while (1) { |
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139 | if (! b->op->get_order(b,left)) { |
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140 | b->op->mark_busy(b, left); |
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141 | return left; |
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142 | } |
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143 | |||
144 | order = b->op->get_order(b, left); |
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145 | |||
146 | right = b->op->bisect(b, left); |
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147 | b->op->set_order(b, left, order-1); |
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148 | b->op->set_order(b, right, order-1); |
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149 | |||
150 | tmp = b->op->find_block(b, block, BUDDY_SYSTEM_INNER_BLOCK); |
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151 | |||
152 | if (tmp == right) { |
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153 | right = left; |
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154 | left = tmp; |
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822 | palkovsky | 155 | } |
156 | ASSERT(tmp == left); |
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814 | palkovsky | 157 | b->op->mark_busy(b, left); |
158 | buddy_system_free(b, right); |
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159 | b->op->mark_available(b, left); |
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160 | } |
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161 | } |
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162 | |||
377 | jermar | 163 | /** Allocate block from buddy system. |
164 | * |
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165 | * @param b Buddy system pointer. |
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166 | * @param i Returned block will be 2^i big. |
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167 | * |
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168 | * @return Block of data represented by link_t. |
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169 | */ |
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170 | link_t *buddy_system_alloc(buddy_system_t *b, __u8 i) |
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171 | { |
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172 | link_t *res, *hlp; |
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173 | |||
735 | bondari | 174 | ASSERT(i <= b->max_order); |
377 | jermar | 175 | |
176 | /* |
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177 | * If the list of order i is not empty, |
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178 | * the request can be immediatelly satisfied. |
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179 | */ |
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180 | if (!list_empty(&b->order[i])) { |
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181 | res = b->order[i].next; |
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182 | list_remove(res); |
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533 | bondari | 183 | b->op->mark_busy(b, res); |
377 | jermar | 184 | return res; |
185 | } |
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186 | /* |
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187 | * If order i is already the maximal order, |
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188 | * the request cannot be satisfied. |
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189 | */ |
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735 | bondari | 190 | if (i == b->max_order) |
377 | jermar | 191 | return NULL; |
192 | |||
193 | /* |
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194 | * Try to recursively satisfy the request from higher order lists. |
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195 | */ |
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196 | hlp = buddy_system_alloc(b, i + 1); |
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197 | |||
198 | /* |
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199 | * The request could not be satisfied |
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200 | * from higher order lists. |
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201 | */ |
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202 | if (!hlp) |
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203 | return NULL; |
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204 | |||
205 | res = hlp; |
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206 | |||
207 | /* |
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208 | * Bisect the block and set order of both of its parts to i. |
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209 | */ |
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489 | jermar | 210 | hlp = b->op->bisect(b, res); |
211 | b->op->set_order(b, res, i); |
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212 | b->op->set_order(b, hlp, i); |
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377 | jermar | 213 | |
214 | /* |
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814 | palkovsky | 215 | * Return the other half to buddy system. Mark the first part |
815 | jermar | 216 | * full, so that it won't coalesce again. |
377 | jermar | 217 | */ |
533 | bondari | 218 | b->op->mark_busy(b, res); |
377 | jermar | 219 | buddy_system_free(b, hlp); |
220 | |||
221 | return res; |
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222 | |||
223 | } |
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224 | |||
225 | /** Return block to buddy system. |
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226 | * |
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227 | * @param b Buddy system pointer. |
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228 | * @param block Block to return. |
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229 | */ |
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230 | void buddy_system_free(buddy_system_t *b, link_t *block) |
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231 | { |
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232 | link_t *buddy, *hlp; |
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233 | __u8 i; |
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533 | bondari | 234 | |
377 | jermar | 235 | /* |
236 | * Determine block's order. |
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237 | */ |
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489 | jermar | 238 | i = b->op->get_order(b, block); |
377 | jermar | 239 | |
735 | bondari | 240 | ASSERT(i <= b->max_order); |
377 | jermar | 241 | |
735 | bondari | 242 | if (i != b->max_order) { |
377 | jermar | 243 | /* |
379 | jermar | 244 | * See if there is any buddy in the list of order i. |
377 | jermar | 245 | */ |
489 | jermar | 246 | buddy = b->op->find_buddy(b, block); |
379 | jermar | 247 | if (buddy) { |
248 | |||
489 | jermar | 249 | ASSERT(b->op->get_order(b, buddy) == i); |
379 | jermar | 250 | /* |
251 | * Remove buddy from the list of order i. |
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252 | */ |
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253 | list_remove(buddy); |
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378 | jermar | 254 | |
379 | jermar | 255 | /* |
256 | * Invalidate order of both block and buddy. |
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257 | */ |
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489 | jermar | 258 | b->op->set_order(b, block, BUDDY_SYSTEM_INNER_BLOCK); |
259 | b->op->set_order(b, buddy, BUDDY_SYSTEM_INNER_BLOCK); |
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379 | jermar | 260 | |
261 | /* |
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262 | * Coalesce block and buddy into one block. |
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263 | */ |
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489 | jermar | 264 | hlp = b->op->coalesce(b, block, buddy); |
377 | jermar | 265 | |
379 | jermar | 266 | /* |
267 | * Set order of the coalesced block to i + 1. |
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268 | */ |
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489 | jermar | 269 | b->op->set_order(b, hlp, i + 1); |
377 | jermar | 270 | |
379 | jermar | 271 | /* |
272 | * Recursively add the coalesced block to the list of order i + 1. |
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273 | */ |
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274 | buddy_system_free(b, hlp); |
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275 | return; |
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276 | } |
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377 | jermar | 277 | } |
278 | |||
379 | jermar | 279 | /* |
280 | * Insert block into the list of order i. |
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281 | */ |
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282 | list_append(block, &b->order[i]); |
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283 | |||
377 | jermar | 284 | } |
683 | bondari | 285 | |
286 | /** Prints out structure of buddy system |
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287 | * |
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288 | * @param b Pointer to buddy system |
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1708 | jermar | 289 | * @param elem_size Element size |
683 | bondari | 290 | */ |
686 | bondari | 291 | void buddy_system_structure_print(buddy_system_t *b, size_t elem_size) { |
683 | bondari | 292 | index_t i; |
293 | count_t cnt, elem_count = 0, block_count = 0; |
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294 | link_t * cur; |
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295 | |||
296 | |||
686 | bondari | 297 | printf("Order\tBlocks\tSize \tBlock size\tElems per block\n"); |
298 | printf("-----\t------\t--------\t----------\t---------------\n"); |
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683 | bondari | 299 | |
735 | bondari | 300 | for (i=0;i <= b->max_order; i++) { |
683 | bondari | 301 | cnt = 0; |
302 | if (!list_empty(&b->order[i])) { |
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701 | jermar | 303 | for (cur = b->order[i].next; cur != &b->order[i]; cur = cur->next) |
304 | cnt++; |
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683 | bondari | 305 | } |
306 | |||
1224 | cejka | 307 | printf("#%zd\t%5zd\t%7zdK\t%8zdK\t%6zd\t", i, cnt, (cnt * (1 << i) * elem_size) >> 10, ((1 << i) * elem_size) >> 10, 1 << i); |
822 | palkovsky | 308 | if (!list_empty(&b->order[i])) { |
309 | for (cur = b->order[i].next; cur != &b->order[i]; cur = cur->next) { |
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310 | b->op->print_id(b, cur); |
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311 | printf(" "); |
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312 | } |
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313 | } |
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314 | printf("\n"); |
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315 | |||
683 | bondari | 316 | block_count += cnt; |
317 | elem_count += (1 << i) * cnt; |
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318 | } |
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686 | bondari | 319 | printf("-----\t------\t--------\t----------\t---------------\n"); |
1196 | cejka | 320 | printf("Buddy system contains %zd free elements (%zd blocks)\n" , elem_count, block_count); |
683 | bondari | 321 | |
322 | } |
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1702 | cejka | 323 | |
324 | /** @} |
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325 | */ |
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326 |