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1123 | serge | 1 | /************************************************************************** |
2 | * |
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3 | * Copyright 2006 Tungsten Graphics, Inc., Bismarck, ND., USA. |
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4 | * All Rights Reserved. |
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5 | * |
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6 | * Permission is hereby granted, free of charge, to any person obtaining a |
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7 | * copy of this software and associated documentation files (the |
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8 | * "Software"), to deal in the Software without restriction, including |
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9 | * without limitation the rights to use, copy, modify, merge, publish, |
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10 | * distribute, sub license, and/or sell copies of the Software, and to |
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11 | * permit persons to whom the Software is furnished to do so, subject to |
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12 | * the following conditions: |
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13 | * |
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14 | * The above copyright notice and this permission notice (including the |
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15 | * next paragraph) shall be included in all copies or substantial portions |
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16 | * of the Software. |
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17 | * |
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18 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
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19 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
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20 | * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL |
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21 | * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, |
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22 | * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR |
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23 | * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE |
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24 | * USE OR OTHER DEALINGS IN THE SOFTWARE. |
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25 | * |
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26 | * |
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27 | **************************************************************************/ |
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28 | |||
29 | /* |
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30 | * Generic simple memory manager implementation. Intended to be used as a base |
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31 | * class implementation for more advanced memory managers. |
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32 | * |
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33 | * Note that the algorithm used is quite simple and there might be substantial |
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34 | * performance gains if a smarter free list is implemented. Currently it is just an |
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35 | * unordered stack of free regions. This could easily be improved if an RB-tree |
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36 | * is used instead. At least if we expect heavy fragmentation. |
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37 | * |
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38 | * Aligned allocations can also see improvement. |
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39 | * |
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40 | * Authors: |
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41 | * Thomas Hellström |
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42 | */ |
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43 | |||
44 | //#include "drmP.h" |
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45 | #include "drm_mm.h" |
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46 | //#include |
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47 | |||
48 | #define MM_UNUSED_TARGET 4 |
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49 | |||
50 | unsigned long drm_mm_tail_space(struct drm_mm *mm) |
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51 | { |
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52 | struct list_head *tail_node; |
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53 | struct drm_mm_node *entry; |
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54 | |||
55 | tail_node = mm->ml_entry.prev; |
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56 | entry = list_entry(tail_node, struct drm_mm_node, ml_entry); |
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57 | if (!entry->free) |
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58 | return 0; |
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59 | |||
60 | return entry->size; |
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61 | } |
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62 | |||
63 | int drm_mm_remove_space_from_tail(struct drm_mm *mm, unsigned long size) |
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64 | { |
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65 | struct list_head *tail_node; |
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66 | struct drm_mm_node *entry; |
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67 | |||
68 | tail_node = mm->ml_entry.prev; |
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69 | entry = list_entry(tail_node, struct drm_mm_node, ml_entry); |
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70 | if (!entry->free) |
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71 | return -ENOMEM; |
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72 | |||
73 | if (entry->size <= size) |
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74 | return -ENOMEM; |
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75 | |||
76 | entry->size -= size; |
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77 | return 0; |
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78 | } |
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79 | |||
80 | static struct drm_mm_node *drm_mm_kmalloc(struct drm_mm *mm, int atomic) |
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81 | { |
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82 | struct drm_mm_node *child; |
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83 | |||
84 | child = malloc(sizeof(*child)); |
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85 | |||
86 | if (unlikely(child == NULL)) { |
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87 | spin_lock(&mm->unused_lock); |
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88 | if (list_empty(&mm->unused_nodes)) |
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89 | child = NULL; |
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90 | else { |
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91 | child = |
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92 | list_entry(mm->unused_nodes.next, |
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93 | struct drm_mm_node, fl_entry); |
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94 | list_del(&child->fl_entry); |
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95 | --mm->num_unused; |
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96 | } |
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97 | spin_unlock(&mm->unused_lock); |
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98 | } |
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99 | return child; |
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100 | } |
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101 | |||
102 | int drm_mm_pre_get(struct drm_mm *mm) |
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103 | { |
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104 | struct drm_mm_node *node; |
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105 | |||
106 | spin_lock(&mm->unused_lock); |
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107 | while (mm->num_unused < MM_UNUSED_TARGET) { |
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108 | spin_unlock(&mm->unused_lock); |
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109 | node = kmalloc(sizeof(*node), GFP_KERNEL); |
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110 | spin_lock(&mm->unused_lock); |
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111 | |||
112 | if (unlikely(node == NULL)) { |
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113 | int ret = (mm->num_unused < 2) ? -ENOMEM : 0; |
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114 | spin_unlock(&mm->unused_lock); |
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115 | return ret; |
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116 | } |
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117 | ++mm->num_unused; |
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118 | list_add_tail(&node->fl_entry, &mm->unused_nodes); |
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119 | } |
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120 | spin_unlock(&mm->unused_lock); |
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121 | return 0; |
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122 | } |
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123 | //EXPORT_SYMBOL(drm_mm_pre_get); |
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124 | |||
125 | static int drm_mm_create_tail_node(struct drm_mm *mm, |
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126 | unsigned long start, |
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127 | unsigned long size, int atomic) |
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128 | { |
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129 | struct drm_mm_node *child; |
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130 | |||
131 | child = drm_mm_kmalloc(mm, atomic); |
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132 | if (unlikely(child == NULL)) |
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133 | return -ENOMEM; |
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134 | |||
135 | child->free = 1; |
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136 | child->size = size; |
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137 | child->start = start; |
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138 | child->mm = mm; |
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139 | |||
140 | list_add_tail(&child->ml_entry, &mm->ml_entry); |
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141 | list_add_tail(&child->fl_entry, &mm->fl_entry); |
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142 | |||
143 | return 0; |
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144 | } |
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145 | |||
146 | int drm_mm_add_space_to_tail(struct drm_mm *mm, unsigned long size, int atomic) |
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147 | { |
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148 | struct list_head *tail_node; |
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149 | struct drm_mm_node *entry; |
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150 | |||
151 | tail_node = mm->ml_entry.prev; |
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152 | entry = list_entry(tail_node, struct drm_mm_node, ml_entry); |
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153 | if (!entry->free) { |
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154 | return drm_mm_create_tail_node(mm, entry->start + entry->size, |
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155 | size, atomic); |
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156 | } |
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157 | entry->size += size; |
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158 | return 0; |
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159 | } |
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160 | |||
161 | static struct drm_mm_node *drm_mm_split_at_start(struct drm_mm_node *parent, |
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162 | unsigned long size, |
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163 | int atomic) |
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164 | { |
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165 | struct drm_mm_node *child; |
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166 | |||
167 | child = drm_mm_kmalloc(parent->mm, atomic); |
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168 | if (unlikely(child == NULL)) |
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169 | return NULL; |
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170 | |||
171 | INIT_LIST_HEAD(&child->fl_entry); |
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172 | |||
173 | child->free = 0; |
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174 | child->size = size; |
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175 | child->start = parent->start; |
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176 | child->mm = parent->mm; |
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177 | |||
178 | list_add_tail(&child->ml_entry, &parent->ml_entry); |
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179 | INIT_LIST_HEAD(&child->fl_entry); |
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180 | |||
181 | parent->size -= size; |
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182 | parent->start += size; |
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183 | return child; |
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184 | } |
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185 | |||
186 | |||
187 | struct drm_mm_node *drm_mm_get_block_generic(struct drm_mm_node *node, |
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188 | unsigned long size, |
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189 | unsigned alignment, |
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190 | int atomic) |
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191 | { |
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192 | |||
193 | struct drm_mm_node *align_splitoff = NULL; |
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194 | unsigned tmp = 0; |
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195 | |||
196 | if (alignment) |
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197 | tmp = node->start % alignment; |
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198 | |||
199 | if (tmp) { |
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200 | align_splitoff = |
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201 | drm_mm_split_at_start(node, alignment - tmp, atomic); |
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202 | if (unlikely(align_splitoff == NULL)) |
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203 | return NULL; |
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204 | } |
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205 | |||
206 | if (node->size == size) { |
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207 | list_del_init(&node->fl_entry); |
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208 | node->free = 0; |
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209 | } else { |
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210 | node = drm_mm_split_at_start(node, size, atomic); |
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211 | } |
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212 | |||
213 | if (align_splitoff) |
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214 | drm_mm_put_block(align_splitoff); |
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215 | |||
216 | return node; |
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217 | } |
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218 | //EXPORT_SYMBOL(drm_mm_get_block_generic); |
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219 | |||
220 | /* |
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221 | * Put a block. Merge with the previous and / or next block if they are free. |
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222 | * Otherwise add to the free stack. |
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223 | */ |
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224 | |||
225 | void drm_mm_put_block(struct drm_mm_node *cur) |
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226 | { |
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227 | |||
228 | struct drm_mm *mm = cur->mm; |
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229 | struct list_head *cur_head = &cur->ml_entry; |
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230 | struct list_head *root_head = &mm->ml_entry; |
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231 | struct drm_mm_node *prev_node = NULL; |
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232 | struct drm_mm_node *next_node; |
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233 | |||
234 | int merged = 0; |
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235 | |||
236 | if (cur_head->prev != root_head) { |
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237 | prev_node = |
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238 | list_entry(cur_head->prev, struct drm_mm_node, ml_entry); |
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239 | if (prev_node->free) { |
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240 | prev_node->size += cur->size; |
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241 | merged = 1; |
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242 | } |
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243 | } |
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244 | if (cur_head->next != root_head) { |
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245 | next_node = |
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246 | list_entry(cur_head->next, struct drm_mm_node, ml_entry); |
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247 | if (next_node->free) { |
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248 | if (merged) { |
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249 | prev_node->size += next_node->size; |
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250 | list_del(&next_node->ml_entry); |
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251 | list_del(&next_node->fl_entry); |
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252 | if (mm->num_unused < MM_UNUSED_TARGET) { |
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253 | list_add(&next_node->fl_entry, |
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254 | &mm->unused_nodes); |
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255 | ++mm->num_unused; |
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256 | } else |
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257 | kfree(next_node); |
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258 | } else { |
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259 | next_node->size += cur->size; |
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260 | next_node->start = cur->start; |
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261 | merged = 1; |
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262 | } |
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263 | } |
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264 | } |
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265 | if (!merged) { |
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266 | cur->free = 1; |
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267 | list_add(&cur->fl_entry, &mm->fl_entry); |
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268 | } else { |
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269 | list_del(&cur->ml_entry); |
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270 | if (mm->num_unused < MM_UNUSED_TARGET) { |
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271 | list_add(&cur->fl_entry, &mm->unused_nodes); |
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272 | ++mm->num_unused; |
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273 | } else |
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274 | kfree(cur); |
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275 | } |
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276 | } |
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277 | |||
278 | //EXPORT_SYMBOL(drm_mm_put_block); |
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279 | |||
280 | struct drm_mm_node *drm_mm_search_free(const struct drm_mm *mm, |
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281 | unsigned long size, |
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282 | unsigned alignment, int best_match) |
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283 | { |
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284 | struct list_head *list; |
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285 | const struct list_head *free_stack = &mm->fl_entry; |
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286 | struct drm_mm_node *entry; |
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287 | struct drm_mm_node *best; |
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288 | unsigned long best_size; |
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289 | unsigned wasted; |
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290 | |||
291 | best = NULL; |
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292 | best_size = ~0UL; |
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293 | |||
294 | list_for_each(list, free_stack) { |
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295 | entry = list_entry(list, struct drm_mm_node, fl_entry); |
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296 | wasted = 0; |
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297 | |||
298 | if (entry->size < size) |
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299 | continue; |
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300 | |||
301 | if (alignment) { |
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302 | register unsigned tmp = entry->start % alignment; |
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303 | if (tmp) |
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304 | wasted += alignment - tmp; |
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305 | } |
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306 | |||
307 | if (entry->size >= size + wasted) { |
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308 | if (!best_match) |
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309 | return entry; |
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310 | if (size < best_size) { |
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311 | best = entry; |
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312 | best_size = entry->size; |
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313 | } |
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314 | } |
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315 | } |
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316 | |||
317 | return best; |
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318 | } |
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319 | //EXPORT_SYMBOL(drm_mm_search_free); |
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320 | |||
321 | int drm_mm_clean(struct drm_mm * mm) |
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322 | { |
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323 | struct list_head *head = &mm->ml_entry; |
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324 | |||
325 | return (head->next->next == head); |
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326 | } |
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327 | //EXPORT_SYMBOL(drm_mm_clean); |
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328 | |||
329 | int drm_mm_init(struct drm_mm * mm, unsigned long start, unsigned long size) |
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330 | { |
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331 | INIT_LIST_HEAD(&mm->ml_entry); |
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332 | INIT_LIST_HEAD(&mm->fl_entry); |
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333 | INIT_LIST_HEAD(&mm->unused_nodes); |
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334 | mm->num_unused = 0; |
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335 | spin_lock_init(&mm->unused_lock); |
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336 | |||
337 | return drm_mm_create_tail_node(mm, start, size, 0); |
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338 | } |
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339 | //EXPORT_SYMBOL(drm_mm_init); |
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340 | |||
341 | void drm_mm_takedown(struct drm_mm * mm) |
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342 | { |
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343 | struct list_head *bnode = mm->fl_entry.next; |
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344 | struct drm_mm_node *entry; |
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345 | struct drm_mm_node *next; |
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346 | |||
347 | entry = list_entry(bnode, struct drm_mm_node, fl_entry); |
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348 | |||
349 | if (entry->ml_entry.next != &mm->ml_entry || |
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350 | entry->fl_entry.next != &mm->fl_entry) { |
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351 | DRM_ERROR("Memory manager not clean. Delaying takedown\n"); |
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352 | return; |
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353 | } |
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354 | |||
355 | list_del(&entry->fl_entry); |
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356 | list_del(&entry->ml_entry); |
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357 | kfree(entry); |
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358 | |||
359 | spin_lock(&mm->unused_lock); |
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360 | list_for_each_entry_safe(entry, next, &mm->unused_nodes, fl_entry) { |
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361 | list_del(&entry->fl_entry); |
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362 | kfree(entry); |
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363 | --mm->num_unused; |
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364 | } |
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365 | spin_unlock(&mm->unused_lock); |
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366 | |||
367 | BUG_ON(mm->num_unused != 0); |
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368 | } |
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369 | //EXPORT_SYMBOL(drm_mm_takedown);>>>>>>=> |