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6084 | serge | 1 | /************************************************************************** |
1123 | serge | 2 | * |
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 | |||
3031 | serge | 44 | #include |
45 | #include |
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1963 | serge | 46 | #include |
1179 | serge | 47 | #include |
3031 | serge | 48 | #include |
1123 | serge | 49 | |
5060 | serge | 50 | /** |
51 | * DOC: Overview |
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52 | * |
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53 | * drm_mm provides a simple range allocator. The drivers are free to use the |
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54 | * resource allocator from the linux core if it suits them, the upside of drm_mm |
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55 | * is that it's in the DRM core. Which means that it's easier to extend for |
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56 | * some of the crazier special purpose needs of gpus. |
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57 | * |
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58 | * The main data struct is &drm_mm, allocations are tracked in &drm_mm_node. |
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59 | * Drivers are free to embed either of them into their own suitable |
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60 | * datastructures. drm_mm itself will not do any allocations of its own, so if |
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61 | * drivers choose not to embed nodes they need to still allocate them |
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62 | * themselves. |
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63 | * |
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64 | * The range allocator also supports reservation of preallocated blocks. This is |
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65 | * useful for taking over initial mode setting configurations from the firmware, |
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66 | * where an object needs to be created which exactly matches the firmware's |
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67 | * scanout target. As long as the range is still free it can be inserted anytime |
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68 | * after the allocator is initialized, which helps with avoiding looped |
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69 | * depencies in the driver load sequence. |
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70 | * |
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71 | * drm_mm maintains a stack of most recently freed holes, which of all |
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72 | * simplistic datastructures seems to be a fairly decent approach to clustering |
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73 | * allocations and avoiding too much fragmentation. This means free space |
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74 | * searches are O(num_holes). Given that all the fancy features drm_mm supports |
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75 | * something better would be fairly complex and since gfx thrashing is a fairly |
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76 | * steep cliff not a real concern. Removing a node again is O(1). |
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77 | * |
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78 | * drm_mm supports a few features: Alignment and range restrictions can be |
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79 | * supplied. Further more every &drm_mm_node has a color value (which is just an |
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80 | * opaqua unsigned long) which in conjunction with a driver callback can be used |
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81 | * to implement sophisticated placement restrictions. The i915 DRM driver uses |
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82 | * this to implement guard pages between incompatible caching domains in the |
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83 | * graphics TT. |
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84 | * |
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85 | * Two behaviors are supported for searching and allocating: bottom-up and top-down. |
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86 | * The default is bottom-up. Top-down allocation can be used if the memory area |
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87 | * has different restrictions, or just to reduce fragmentation. |
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88 | * |
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89 | * Finally iteration helpers to walk all nodes and all holes are provided as are |
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90 | * some basic allocator dumpers for debugging. |
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91 | */ |
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1123 | serge | 92 | |
4104 | Serge | 93 | static struct drm_mm_node *drm_mm_search_free_generic(const struct drm_mm *mm, |
6084 | serge | 94 | u64 size, |
4104 | Serge | 95 | unsigned alignment, |
96 | unsigned long color, |
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97 | enum drm_mm_search_flags flags); |
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98 | static struct drm_mm_node *drm_mm_search_free_in_range_generic(const struct drm_mm *mm, |
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6084 | serge | 99 | u64 size, |
4104 | Serge | 100 | unsigned alignment, |
101 | unsigned long color, |
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6084 | serge | 102 | u64 start, |
103 | u64 end, |
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4104 | Serge | 104 | enum drm_mm_search_flags flags); |
1123 | serge | 105 | |
1963 | serge | 106 | static void drm_mm_insert_helper(struct drm_mm_node *hole_node, |
107 | struct drm_mm_node *node, |
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6084 | serge | 108 | u64 size, unsigned alignment, |
5060 | serge | 109 | unsigned long color, |
110 | enum drm_mm_allocator_flags flags) |
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1123 | serge | 111 | { |
1963 | serge | 112 | struct drm_mm *mm = hole_node->mm; |
6084 | serge | 113 | u64 hole_start = drm_mm_hole_node_start(hole_node); |
114 | u64 hole_end = drm_mm_hole_node_end(hole_node); |
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115 | u64 adj_start = hole_start; |
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116 | u64 adj_end = hole_end; |
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1123 | serge | 117 | |
3480 | Serge | 118 | BUG_ON(node->allocated); |
1963 | serge | 119 | |
3031 | serge | 120 | if (mm->color_adjust) |
121 | mm->color_adjust(hole_node, color, &adj_start, &adj_end); |
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1963 | serge | 122 | |
5060 | serge | 123 | if (flags & DRM_MM_CREATE_TOP) |
124 | adj_start = adj_end - size; |
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125 | |||
3031 | serge | 126 | if (alignment) { |
6084 | serge | 127 | u64 tmp = adj_start; |
128 | unsigned rem; |
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129 | |||
130 | rem = do_div(tmp, alignment); |
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131 | if (rem) { |
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5060 | serge | 132 | if (flags & DRM_MM_CREATE_TOP) |
6084 | serge | 133 | adj_start -= rem; |
5060 | serge | 134 | else |
6084 | serge | 135 | adj_start += alignment - rem; |
136 | } |
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3031 | serge | 137 | } |
138 | |||
5060 | serge | 139 | BUG_ON(adj_start < hole_start); |
140 | BUG_ON(adj_end > hole_end); |
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141 | |||
3031 | serge | 142 | if (adj_start == hole_start) { |
1963 | serge | 143 | hole_node->hole_follows = 0; |
3031 | serge | 144 | list_del(&hole_node->hole_stack); |
145 | } |
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1963 | serge | 146 | |
3031 | serge | 147 | node->start = adj_start; |
1963 | serge | 148 | node->size = size; |
149 | node->mm = mm; |
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3031 | serge | 150 | node->color = color; |
1963 | serge | 151 | node->allocated = 1; |
152 | |||
153 | INIT_LIST_HEAD(&node->hole_stack); |
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154 | list_add(&node->node_list, &hole_node->node_list); |
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155 | |||
3031 | serge | 156 | BUG_ON(node->start + node->size > adj_end); |
1963 | serge | 157 | |
3031 | serge | 158 | node->hole_follows = 0; |
3480 | Serge | 159 | if (__drm_mm_hole_node_start(node) < hole_end) { |
1963 | serge | 160 | list_add(&node->hole_stack, &mm->hole_stack); |
161 | node->hole_follows = 1; |
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1123 | serge | 162 | } |
163 | } |
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164 | |||
5060 | serge | 165 | /** |
166 | * drm_mm_reserve_node - insert an pre-initialized node |
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167 | * @mm: drm_mm allocator to insert @node into |
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168 | * @node: drm_mm_node to insert |
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169 | * |
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170 | * This functions inserts an already set-up drm_mm_node into the allocator, |
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171 | * meaning that start, size and color must be set by the caller. This is useful |
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172 | * to initialize the allocator with preallocated objects which must be set-up |
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173 | * before the range allocator can be set-up, e.g. when taking over a firmware |
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174 | * framebuffer. |
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175 | * |
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176 | * Returns: |
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177 | * 0 on success, -ENOSPC if there's no hole where @node is. |
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178 | */ |
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4104 | Serge | 179 | int drm_mm_reserve_node(struct drm_mm *mm, struct drm_mm_node *node) |
3480 | Serge | 180 | { |
4104 | Serge | 181 | struct drm_mm_node *hole; |
6084 | serge | 182 | u64 end = node->start + node->size; |
183 | u64 hole_start; |
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184 | u64 hole_end; |
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3480 | Serge | 185 | |
4104 | Serge | 186 | BUG_ON(node == NULL); |
187 | |||
188 | /* Find the relevant hole to add our node to */ |
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3480 | Serge | 189 | drm_mm_for_each_hole(hole, mm, hole_start, hole_end) { |
4104 | Serge | 190 | if (hole_start > node->start || hole_end < end) |
3480 | Serge | 191 | continue; |
192 | |||
193 | node->mm = mm; |
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194 | node->allocated = 1; |
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195 | |||
196 | INIT_LIST_HEAD(&node->hole_stack); |
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197 | list_add(&node->node_list, &hole->node_list); |
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198 | |||
4104 | Serge | 199 | if (node->start == hole_start) { |
3480 | Serge | 200 | hole->hole_follows = 0; |
201 | list_del_init(&hole->hole_stack); |
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202 | } |
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203 | |||
204 | node->hole_follows = 0; |
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205 | if (end != hole_end) { |
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206 | list_add(&node->hole_stack, &mm->hole_stack); |
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207 | node->hole_follows = 1; |
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208 | } |
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209 | |||
4104 | Serge | 210 | return 0; |
3480 | Serge | 211 | } |
212 | |||
4104 | Serge | 213 | return -ENOSPC; |
3480 | Serge | 214 | } |
4104 | Serge | 215 | EXPORT_SYMBOL(drm_mm_reserve_node); |
3480 | Serge | 216 | |
1963 | serge | 217 | /** |
5060 | serge | 218 | * drm_mm_insert_node_generic - search for space and insert @node |
219 | * @mm: drm_mm to allocate from |
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220 | * @node: preallocate node to insert |
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221 | * @size: size of the allocation |
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222 | * @alignment: alignment of the allocation |
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223 | * @color: opaque tag value to use for this node |
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224 | * @sflags: flags to fine-tune the allocation search |
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225 | * @aflags: flags to fine-tune the allocation behavior |
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226 | * |
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227 | * The preallocated node must be cleared to 0. |
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228 | * |
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229 | * Returns: |
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230 | * 0 on success, -ENOSPC if there's no suitable hole. |
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1963 | serge | 231 | */ |
3192 | Serge | 232 | int drm_mm_insert_node_generic(struct drm_mm *mm, struct drm_mm_node *node, |
6084 | serge | 233 | u64 size, unsigned alignment, |
4104 | Serge | 234 | unsigned long color, |
5060 | serge | 235 | enum drm_mm_search_flags sflags, |
236 | enum drm_mm_allocator_flags aflags) |
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1963 | serge | 237 | { |
238 | struct drm_mm_node *hole_node; |
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1123 | serge | 239 | |
3192 | Serge | 240 | hole_node = drm_mm_search_free_generic(mm, size, alignment, |
5060 | serge | 241 | color, sflags); |
1963 | serge | 242 | if (!hole_node) |
243 | return -ENOSPC; |
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244 | |||
5060 | serge | 245 | drm_mm_insert_helper(hole_node, node, size, alignment, color, aflags); |
1963 | serge | 246 | return 0; |
1123 | serge | 247 | } |
3192 | Serge | 248 | EXPORT_SYMBOL(drm_mm_insert_node_generic); |
249 | |||
1963 | serge | 250 | static void drm_mm_insert_helper_range(struct drm_mm_node *hole_node, |
251 | struct drm_mm_node *node, |
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6084 | serge | 252 | u64 size, unsigned alignment, |
3031 | serge | 253 | unsigned long color, |
6084 | serge | 254 | u64 start, u64 end, |
5060 | serge | 255 | enum drm_mm_allocator_flags flags) |
1123 | serge | 256 | { |
1963 | serge | 257 | struct drm_mm *mm = hole_node->mm; |
6084 | serge | 258 | u64 hole_start = drm_mm_hole_node_start(hole_node); |
259 | u64 hole_end = drm_mm_hole_node_end(hole_node); |
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260 | u64 adj_start = hole_start; |
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261 | u64 adj_end = hole_end; |
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1123 | serge | 262 | |
1963 | serge | 263 | BUG_ON(!hole_node->hole_follows || node->allocated); |
1123 | serge | 264 | |
3192 | Serge | 265 | if (adj_start < start) |
266 | adj_start = start; |
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267 | if (adj_end > end) |
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268 | adj_end = end; |
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269 | |||
6084 | serge | 270 | if (mm->color_adjust) |
271 | mm->color_adjust(hole_node, color, &adj_start, &adj_end); |
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272 | |||
5060 | serge | 273 | if (flags & DRM_MM_CREATE_TOP) |
274 | adj_start = adj_end - size; |
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275 | |||
6084 | serge | 276 | if (alignment) { |
277 | u64 tmp = adj_start; |
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278 | unsigned rem; |
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1123 | serge | 279 | |
6084 | serge | 280 | rem = do_div(tmp, alignment); |
281 | if (rem) { |
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5060 | serge | 282 | if (flags & DRM_MM_CREATE_TOP) |
6084 | serge | 283 | adj_start -= rem; |
5060 | serge | 284 | else |
6084 | serge | 285 | adj_start += alignment - rem; |
286 | } |
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3031 | serge | 287 | } |
1963 | serge | 288 | |
3031 | serge | 289 | if (adj_start == hole_start) { |
1963 | serge | 290 | hole_node->hole_follows = 0; |
3031 | serge | 291 | list_del(&hole_node->hole_stack); |
1123 | serge | 292 | } |
293 | |||
3031 | serge | 294 | node->start = adj_start; |
1963 | serge | 295 | node->size = size; |
296 | node->mm = mm; |
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3031 | serge | 297 | node->color = color; |
1963 | serge | 298 | node->allocated = 1; |
299 | |||
300 | INIT_LIST_HEAD(&node->hole_stack); |
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301 | list_add(&node->node_list, &hole_node->node_list); |
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302 | |||
5060 | serge | 303 | BUG_ON(node->start < start); |
304 | BUG_ON(node->start < adj_start); |
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3031 | serge | 305 | BUG_ON(node->start + node->size > adj_end); |
1963 | serge | 306 | BUG_ON(node->start + node->size > end); |
307 | |||
3031 | serge | 308 | node->hole_follows = 0; |
3480 | Serge | 309 | if (__drm_mm_hole_node_start(node) < hole_end) { |
1963 | serge | 310 | list_add(&node->hole_stack, &mm->hole_stack); |
311 | node->hole_follows = 1; |
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1123 | serge | 312 | } |
313 | } |
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314 | |||
1963 | serge | 315 | /** |
5060 | serge | 316 | * drm_mm_insert_node_in_range_generic - ranged search for space and insert @node |
317 | * @mm: drm_mm to allocate from |
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318 | * @node: preallocate node to insert |
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319 | * @size: size of the allocation |
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320 | * @alignment: alignment of the allocation |
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321 | * @color: opaque tag value to use for this node |
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322 | * @start: start of the allowed range for this node |
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323 | * @end: end of the allowed range for this node |
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324 | * @sflags: flags to fine-tune the allocation search |
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325 | * @aflags: flags to fine-tune the allocation behavior |
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326 | * |
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327 | * The preallocated node must be cleared to 0. |
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328 | * |
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329 | * Returns: |
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330 | * 0 on success, -ENOSPC if there's no suitable hole. |
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1123 | serge | 331 | */ |
3192 | Serge | 332 | int drm_mm_insert_node_in_range_generic(struct drm_mm *mm, struct drm_mm_node *node, |
6084 | serge | 333 | u64 size, unsigned alignment, |
5060 | serge | 334 | unsigned long color, |
6084 | serge | 335 | u64 start, u64 end, |
5060 | serge | 336 | enum drm_mm_search_flags sflags, |
337 | enum drm_mm_allocator_flags aflags) |
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1963 | serge | 338 | { |
339 | struct drm_mm_node *hole_node; |
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1123 | serge | 340 | |
3192 | Serge | 341 | hole_node = drm_mm_search_free_in_range_generic(mm, |
342 | size, alignment, color, |
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5060 | serge | 343 | start, end, sflags); |
1963 | serge | 344 | if (!hole_node) |
345 | return -ENOSPC; |
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346 | |||
3192 | Serge | 347 | drm_mm_insert_helper_range(hole_node, node, |
348 | size, alignment, color, |
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5060 | serge | 349 | start, end, aflags); |
1963 | serge | 350 | return 0; |
351 | } |
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3192 | Serge | 352 | EXPORT_SYMBOL(drm_mm_insert_node_in_range_generic); |
353 | |||
1963 | serge | 354 | /** |
5060 | serge | 355 | * drm_mm_remove_node - Remove a memory node from the allocator. |
356 | * @node: drm_mm_node to remove |
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357 | * |
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358 | * This just removes a node from its drm_mm allocator. The node does not need to |
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359 | * be cleared again before it can be re-inserted into this or any other drm_mm |
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360 | * allocator. It is a bug to call this function on a un-allocated node. |
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1963 | serge | 361 | */ |
362 | void drm_mm_remove_node(struct drm_mm_node *node) |
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1123 | serge | 363 | { |
1963 | serge | 364 | struct drm_mm *mm = node->mm; |
365 | struct drm_mm_node *prev_node; |
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1123 | serge | 366 | |
4104 | Serge | 367 | if (WARN_ON(!node->allocated)) |
368 | return; |
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369 | |||
1963 | serge | 370 | BUG_ON(node->scanned_block || node->scanned_prev_free |
371 | || node->scanned_next_free); |
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1123 | serge | 372 | |
1963 | serge | 373 | prev_node = |
374 | list_entry(node->node_list.prev, struct drm_mm_node, node_list); |
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1123 | serge | 375 | |
1963 | serge | 376 | if (node->hole_follows) { |
3480 | Serge | 377 | BUG_ON(__drm_mm_hole_node_start(node) == |
378 | __drm_mm_hole_node_end(node)); |
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1963 | serge | 379 | list_del(&node->hole_stack); |
380 | } else |
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3480 | Serge | 381 | BUG_ON(__drm_mm_hole_node_start(node) != |
382 | __drm_mm_hole_node_end(node)); |
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1963 | serge | 383 | |
3480 | Serge | 384 | |
1963 | serge | 385 | if (!prev_node->hole_follows) { |
386 | prev_node->hole_follows = 1; |
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387 | list_add(&prev_node->hole_stack, &mm->hole_stack); |
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6084 | serge | 388 | } else |
1963 | serge | 389 | list_move(&prev_node->hole_stack, &mm->hole_stack); |
390 | |||
391 | list_del(&node->node_list); |
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392 | node->allocated = 0; |
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393 | } |
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394 | EXPORT_SYMBOL(drm_mm_remove_node); |
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395 | |||
6084 | serge | 396 | static int check_free_hole(u64 start, u64 end, u64 size, unsigned alignment) |
1963 | serge | 397 | { |
398 | if (end - start < size) |
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399 | return 0; |
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400 | |||
401 | if (alignment) { |
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6084 | serge | 402 | u64 tmp = start; |
403 | unsigned rem; |
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404 | |||
405 | rem = do_div(tmp, alignment); |
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406 | if (rem) |
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407 | start += alignment - rem; |
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1123 | serge | 408 | } |
1963 | serge | 409 | |
3031 | serge | 410 | return end >= start + size; |
1123 | serge | 411 | } |
412 | |||
4104 | Serge | 413 | static struct drm_mm_node *drm_mm_search_free_generic(const struct drm_mm *mm, |
6084 | serge | 414 | u64 size, |
415 | unsigned alignment, |
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416 | unsigned long color, |
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4104 | Serge | 417 | enum drm_mm_search_flags flags) |
1123 | serge | 418 | { |
419 | struct drm_mm_node *entry; |
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420 | struct drm_mm_node *best; |
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6084 | serge | 421 | u64 adj_start; |
422 | u64 adj_end; |
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423 | u64 best_size; |
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1123 | serge | 424 | |
1963 | serge | 425 | BUG_ON(mm->scanned_blocks); |
426 | |||
1123 | serge | 427 | best = NULL; |
428 | best_size = ~0UL; |
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429 | |||
5060 | serge | 430 | __drm_mm_for_each_hole(entry, mm, adj_start, adj_end, |
431 | flags & DRM_MM_SEARCH_BELOW) { |
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6084 | serge | 432 | u64 hole_size = adj_end - adj_start; |
5060 | serge | 433 | |
3031 | serge | 434 | if (mm->color_adjust) { |
435 | mm->color_adjust(entry, color, &adj_start, &adj_end); |
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436 | if (adj_end <= adj_start) |
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437 | continue; |
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438 | } |
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439 | |||
440 | if (!check_free_hole(adj_start, adj_end, size, alignment)) |
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1123 | serge | 441 | continue; |
442 | |||
4104 | Serge | 443 | if (!(flags & DRM_MM_SEARCH_BEST)) |
6084 | serge | 444 | return entry; |
1963 | serge | 445 | |
5060 | serge | 446 | if (hole_size < best_size) { |
6084 | serge | 447 | best = entry; |
5060 | serge | 448 | best_size = hole_size; |
1123 | serge | 449 | } |
6084 | serge | 450 | } |
1123 | serge | 451 | |
452 | return best; |
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453 | } |
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454 | |||
4104 | Serge | 455 | static struct drm_mm_node *drm_mm_search_free_in_range_generic(const struct drm_mm *mm, |
6084 | serge | 456 | u64 size, |
457 | unsigned alignment, |
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3031 | serge | 458 | unsigned long color, |
6084 | serge | 459 | u64 start, |
460 | u64 end, |
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4104 | Serge | 461 | enum drm_mm_search_flags flags) |
1321 | serge | 462 | { |
463 | struct drm_mm_node *entry; |
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464 | struct drm_mm_node *best; |
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6084 | serge | 465 | u64 adj_start; |
466 | u64 adj_end; |
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467 | u64 best_size; |
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1321 | serge | 468 | |
1963 | serge | 469 | BUG_ON(mm->scanned_blocks); |
470 | |||
1321 | serge | 471 | best = NULL; |
472 | best_size = ~0UL; |
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473 | |||
5060 | serge | 474 | __drm_mm_for_each_hole(entry, mm, adj_start, adj_end, |
475 | flags & DRM_MM_SEARCH_BELOW) { |
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6084 | serge | 476 | u64 hole_size = adj_end - adj_start; |
5060 | serge | 477 | |
3480 | Serge | 478 | if (adj_start < start) |
479 | adj_start = start; |
||
480 | if (adj_end > end) |
||
481 | adj_end = end; |
||
1321 | serge | 482 | |
3031 | serge | 483 | if (mm->color_adjust) { |
484 | mm->color_adjust(entry, color, &adj_start, &adj_end); |
||
485 | if (adj_end <= adj_start) |
||
486 | continue; |
||
487 | } |
||
488 | |||
1963 | serge | 489 | if (!check_free_hole(adj_start, adj_end, size, alignment)) |
1321 | serge | 490 | continue; |
491 | |||
4104 | Serge | 492 | if (!(flags & DRM_MM_SEARCH_BEST)) |
6084 | serge | 493 | return entry; |
1963 | serge | 494 | |
5060 | serge | 495 | if (hole_size < best_size) { |
6084 | serge | 496 | best = entry; |
5060 | serge | 497 | best_size = hole_size; |
1321 | serge | 498 | } |
6084 | serge | 499 | } |
1321 | serge | 500 | |
501 | return best; |
||
502 | } |
||
503 | |||
1963 | serge | 504 | /** |
5060 | serge | 505 | * drm_mm_replace_node - move an allocation from @old to @new |
506 | * @old: drm_mm_node to remove from the allocator |
||
507 | * @new: drm_mm_node which should inherit @old's allocation |
||
508 | * |
||
509 | * This is useful for when drivers embed the drm_mm_node structure and hence |
||
510 | * can't move allocations by reassigning pointers. It's a combination of remove |
||
511 | * and insert with the guarantee that the allocation start will match. |
||
1963 | serge | 512 | */ |
513 | void drm_mm_replace_node(struct drm_mm_node *old, struct drm_mm_node *new) |
||
514 | { |
||
515 | list_replace(&old->node_list, &new->node_list); |
||
516 | list_replace(&old->hole_stack, &new->hole_stack); |
||
517 | new->hole_follows = old->hole_follows; |
||
518 | new->mm = old->mm; |
||
519 | new->start = old->start; |
||
520 | new->size = old->size; |
||
3031 | serge | 521 | new->color = old->color; |
1963 | serge | 522 | |
523 | old->allocated = 0; |
||
524 | new->allocated = 1; |
||
525 | } |
||
526 | EXPORT_SYMBOL(drm_mm_replace_node); |
||
527 | |||
528 | /** |
||
5060 | serge | 529 | * DOC: lru scan roaster |
1963 | serge | 530 | * |
5060 | serge | 531 | * Very often GPUs need to have continuous allocations for a given object. When |
532 | * evicting objects to make space for a new one it is therefore not most |
||
533 | * efficient when we simply start to select all objects from the tail of an LRU |
||
534 | * until there's a suitable hole: Especially for big objects or nodes that |
||
535 | * otherwise have special allocation constraints there's a good chance we evict |
||
536 | * lots of (smaller) objects unecessarily. |
||
537 | * |
||
538 | * The DRM range allocator supports this use-case through the scanning |
||
539 | * interfaces. First a scan operation needs to be initialized with |
||
540 | * drm_mm_init_scan() or drm_mm_init_scan_with_range(). The the driver adds |
||
541 | * objects to the roaster (probably by walking an LRU list, but this can be |
||
542 | * freely implemented) until a suitable hole is found or there's no further |
||
543 | * evitable object. |
||
544 | * |
||
545 | * The the driver must walk through all objects again in exactly the reverse |
||
546 | * order to restore the allocator state. Note that while the allocator is used |
||
547 | * in the scan mode no other operation is allowed. |
||
548 | * |
||
549 | * Finally the driver evicts all objects selected in the scan. Adding and |
||
550 | * removing an object is O(1), and since freeing a node is also O(1) the overall |
||
551 | * complexity is O(scanned_objects). So like the free stack which needs to be |
||
552 | * walked before a scan operation even begins this is linear in the number of |
||
553 | * objects. It doesn't seem to hurt badly. |
||
554 | */ |
||
555 | |||
556 | /** |
||
557 | * drm_mm_init_scan - initialize lru scanning |
||
558 | * @mm: drm_mm to scan |
||
559 | * @size: size of the allocation |
||
560 | * @alignment: alignment of the allocation |
||
561 | * @color: opaque tag value to use for the allocation |
||
562 | * |
||
1963 | serge | 563 | * This simply sets up the scanning routines with the parameters for the desired |
5060 | serge | 564 | * hole. Note that there's no need to specify allocation flags, since they only |
565 | * change the place a node is allocated from within a suitable hole. |
||
1963 | serge | 566 | * |
5060 | serge | 567 | * Warning: |
568 | * As long as the scan list is non-empty, no other operations than |
||
1963 | serge | 569 | * adding/removing nodes to/from the scan list are allowed. |
570 | */ |
||
3031 | serge | 571 | void drm_mm_init_scan(struct drm_mm *mm, |
6084 | serge | 572 | u64 size, |
3031 | serge | 573 | unsigned alignment, |
574 | unsigned long color) |
||
1963 | serge | 575 | { |
3031 | serge | 576 | mm->scan_color = color; |
1963 | serge | 577 | mm->scan_alignment = alignment; |
578 | mm->scan_size = size; |
||
579 | mm->scanned_blocks = 0; |
||
580 | mm->scan_hit_start = 0; |
||
3192 | Serge | 581 | mm->scan_hit_end = 0; |
1963 | serge | 582 | mm->scan_check_range = 0; |
583 | mm->prev_scanned_node = NULL; |
||
584 | } |
||
585 | EXPORT_SYMBOL(drm_mm_init_scan); |
||
586 | |||
587 | /** |
||
5060 | serge | 588 | * drm_mm_init_scan - initialize range-restricted lru scanning |
589 | * @mm: drm_mm to scan |
||
590 | * @size: size of the allocation |
||
591 | * @alignment: alignment of the allocation |
||
592 | * @color: opaque tag value to use for the allocation |
||
593 | * @start: start of the allowed range for the allocation |
||
594 | * @end: end of the allowed range for the allocation |
||
1963 | serge | 595 | * |
596 | * This simply sets up the scanning routines with the parameters for the desired |
||
5060 | serge | 597 | * hole. Note that there's no need to specify allocation flags, since they only |
598 | * change the place a node is allocated from within a suitable hole. |
||
1963 | serge | 599 | * |
5060 | serge | 600 | * Warning: |
601 | * As long as the scan list is non-empty, no other operations than |
||
1963 | serge | 602 | * adding/removing nodes to/from the scan list are allowed. |
603 | */ |
||
3031 | serge | 604 | void drm_mm_init_scan_with_range(struct drm_mm *mm, |
6084 | serge | 605 | u64 size, |
1963 | serge | 606 | unsigned alignment, |
3031 | serge | 607 | unsigned long color, |
6084 | serge | 608 | u64 start, |
609 | u64 end) |
||
1963 | serge | 610 | { |
3031 | serge | 611 | mm->scan_color = color; |
1963 | serge | 612 | mm->scan_alignment = alignment; |
613 | mm->scan_size = size; |
||
614 | mm->scanned_blocks = 0; |
||
615 | mm->scan_hit_start = 0; |
||
3192 | Serge | 616 | mm->scan_hit_end = 0; |
1963 | serge | 617 | mm->scan_start = start; |
618 | mm->scan_end = end; |
||
619 | mm->scan_check_range = 1; |
||
620 | mm->prev_scanned_node = NULL; |
||
621 | } |
||
622 | EXPORT_SYMBOL(drm_mm_init_scan_with_range); |
||
623 | |||
624 | /** |
||
5060 | serge | 625 | * drm_mm_scan_add_block - add a node to the scan list |
626 | * @node: drm_mm_node to add |
||
627 | * |
||
1963 | serge | 628 | * Add a node to the scan list that might be freed to make space for the desired |
629 | * hole. |
||
630 | * |
||
5060 | serge | 631 | * Returns: |
632 | * True if a hole has been found, false otherwise. |
||
1963 | serge | 633 | */ |
5060 | serge | 634 | bool drm_mm_scan_add_block(struct drm_mm_node *node) |
1963 | serge | 635 | { |
636 | struct drm_mm *mm = node->mm; |
||
637 | struct drm_mm_node *prev_node; |
||
6084 | serge | 638 | u64 hole_start, hole_end; |
639 | u64 adj_start, adj_end; |
||
1963 | serge | 640 | |
641 | mm->scanned_blocks++; |
||
642 | |||
643 | BUG_ON(node->scanned_block); |
||
644 | node->scanned_block = 1; |
||
645 | |||
6084 | serge | 646 | prev_node = list_entry(node->node_list.prev, struct drm_mm_node, |
647 | node_list); |
||
1963 | serge | 648 | |
649 | node->scanned_preceeds_hole = prev_node->hole_follows; |
||
650 | prev_node->hole_follows = 1; |
||
651 | list_del(&node->node_list); |
||
652 | node->node_list.prev = &prev_node->node_list; |
||
653 | node->node_list.next = &mm->prev_scanned_node->node_list; |
||
654 | mm->prev_scanned_node = node; |
||
655 | |||
3192 | Serge | 656 | adj_start = hole_start = drm_mm_hole_node_start(prev_node); |
657 | adj_end = hole_end = drm_mm_hole_node_end(prev_node); |
||
3031 | serge | 658 | |
659 | if (mm->scan_check_range) { |
||
660 | if (adj_start < mm->scan_start) |
||
661 | adj_start = mm->scan_start; |
||
662 | if (adj_end > mm->scan_end) |
||
663 | adj_end = mm->scan_end; |
||
1963 | serge | 664 | } |
665 | |||
3192 | Serge | 666 | if (mm->color_adjust) |
667 | mm->color_adjust(prev_node, mm->scan_color, |
||
668 | &adj_start, &adj_end); |
||
669 | |||
3031 | serge | 670 | if (check_free_hole(adj_start, adj_end, |
1963 | serge | 671 | mm->scan_size, mm->scan_alignment)) { |
672 | mm->scan_hit_start = hole_start; |
||
3192 | Serge | 673 | mm->scan_hit_end = hole_end; |
5060 | serge | 674 | return true; |
1963 | serge | 675 | } |
676 | |||
5060 | serge | 677 | return false; |
1963 | serge | 678 | } |
679 | EXPORT_SYMBOL(drm_mm_scan_add_block); |
||
680 | |||
681 | /** |
||
5060 | serge | 682 | * drm_mm_scan_remove_block - remove a node from the scan list |
683 | * @node: drm_mm_node to remove |
||
1963 | serge | 684 | * |
685 | * Nodes _must_ be removed in the exact same order from the scan list as they |
||
686 | * have been added, otherwise the internal state of the memory manager will be |
||
687 | * corrupted. |
||
688 | * |
||
689 | * When the scan list is empty, the selected memory nodes can be freed. An |
||
4104 | Serge | 690 | * immediately following drm_mm_search_free with !DRM_MM_SEARCH_BEST will then |
691 | * return the just freed block (because its at the top of the free_stack list). |
||
1963 | serge | 692 | * |
5060 | serge | 693 | * Returns: |
694 | * True if this block should be evicted, false otherwise. Will always |
||
695 | * return false when no hole has been found. |
||
1963 | serge | 696 | */ |
5060 | serge | 697 | bool drm_mm_scan_remove_block(struct drm_mm_node *node) |
1963 | serge | 698 | { |
699 | struct drm_mm *mm = node->mm; |
||
700 | struct drm_mm_node *prev_node; |
||
701 | |||
702 | mm->scanned_blocks--; |
||
703 | |||
704 | BUG_ON(!node->scanned_block); |
||
705 | node->scanned_block = 0; |
||
706 | |||
707 | prev_node = list_entry(node->node_list.prev, struct drm_mm_node, |
||
708 | node_list); |
||
709 | |||
710 | prev_node->hole_follows = node->scanned_preceeds_hole; |
||
711 | list_add(&node->node_list, &prev_node->node_list); |
||
712 | |||
3192 | Serge | 713 | return (drm_mm_hole_node_end(node) > mm->scan_hit_start && |
714 | node->start < mm->scan_hit_end); |
||
1963 | serge | 715 | } |
716 | EXPORT_SYMBOL(drm_mm_scan_remove_block); |
||
717 | |||
5060 | serge | 718 | /** |
719 | * drm_mm_clean - checks whether an allocator is clean |
||
720 | * @mm: drm_mm allocator to check |
||
721 | * |
||
722 | * Returns: |
||
723 | * True if the allocator is completely free, false if there's still a node |
||
724 | * allocated in it. |
||
725 | */ |
||
726 | bool drm_mm_clean(struct drm_mm * mm) |
||
1123 | serge | 727 | { |
1963 | serge | 728 | struct list_head *head = &mm->head_node.node_list; |
1123 | serge | 729 | |
730 | return (head->next->next == head); |
||
731 | } |
||
1126 | serge | 732 | EXPORT_SYMBOL(drm_mm_clean); |
1123 | serge | 733 | |
5060 | serge | 734 | /** |
735 | * drm_mm_init - initialize a drm-mm allocator |
||
736 | * @mm: the drm_mm structure to initialize |
||
737 | * @start: start of the range managed by @mm |
||
738 | * @size: end of the range managed by @mm |
||
739 | * |
||
740 | * Note that @mm must be cleared to 0 before calling this function. |
||
741 | */ |
||
6084 | serge | 742 | void drm_mm_init(struct drm_mm * mm, u64 start, u64 size) |
1123 | serge | 743 | { |
1963 | serge | 744 | INIT_LIST_HEAD(&mm->hole_stack); |
745 | mm->scanned_blocks = 0; |
||
1123 | serge | 746 | |
1963 | serge | 747 | /* Clever trick to avoid a special case in the free hole tracking. */ |
748 | INIT_LIST_HEAD(&mm->head_node.node_list); |
||
749 | INIT_LIST_HEAD(&mm->head_node.hole_stack); |
||
750 | mm->head_node.hole_follows = 1; |
||
751 | mm->head_node.scanned_block = 0; |
||
752 | mm->head_node.scanned_prev_free = 0; |
||
753 | mm->head_node.scanned_next_free = 0; |
||
754 | mm->head_node.mm = mm; |
||
755 | mm->head_node.start = start + size; |
||
756 | mm->head_node.size = start - mm->head_node.start; |
||
757 | list_add_tail(&mm->head_node.hole_stack, &mm->hole_stack); |
||
758 | |||
3031 | serge | 759 | mm->color_adjust = NULL; |
1123 | serge | 760 | } |
1126 | serge | 761 | EXPORT_SYMBOL(drm_mm_init); |
1123 | serge | 762 | |
5060 | serge | 763 | /** |
764 | * drm_mm_takedown - clean up a drm_mm allocator |
||
765 | * @mm: drm_mm allocator to clean up |
||
766 | * |
||
767 | * Note that it is a bug to call this function on an allocator which is not |
||
768 | * clean. |
||
769 | */ |
||
1123 | serge | 770 | void drm_mm_takedown(struct drm_mm * mm) |
771 | { |
||
4104 | Serge | 772 | WARN(!list_empty(&mm->head_node.node_list), |
773 | "Memory manager not clean during takedown.\n"); |
||
1123 | serge | 774 | } |
1126 | serge | 775 | EXPORT_SYMBOL(drm_mm_takedown); |
3192 | Serge | 776 | |
6084 | serge | 777 | static u64 drm_mm_debug_hole(struct drm_mm_node *entry, |
778 | const char *prefix) |
||
3192 | Serge | 779 | { |
6084 | serge | 780 | u64 hole_start, hole_end, hole_size; |
3192 | Serge | 781 | |
4075 | Serge | 782 | if (entry->hole_follows) { |
783 | hole_start = drm_mm_hole_node_start(entry); |
||
784 | hole_end = drm_mm_hole_node_end(entry); |
||
6084 | serge | 785 | hole_size = hole_end - hole_start; |
786 | pr_debug("%s %#llx-%#llx: %llu: free\n", prefix, hole_start, |
||
787 | hole_end, hole_size); |
||
4075 | Serge | 788 | return hole_size; |
789 | } |
||
3192 | Serge | 790 | |
4075 | Serge | 791 | return 0; |
792 | } |
||
793 | |||
5060 | serge | 794 | /** |
795 | * drm_mm_debug_table - dump allocator state to dmesg |
||
796 | * @mm: drm_mm allocator to dump |
||
797 | * @prefix: prefix to use for dumping to dmesg |
||
798 | */ |
||
4075 | Serge | 799 | void drm_mm_debug_table(struct drm_mm *mm, const char *prefix) |
800 | { |
||
801 | struct drm_mm_node *entry; |
||
6084 | serge | 802 | u64 total_used = 0, total_free = 0, total = 0; |
4075 | Serge | 803 | |
804 | total_free += drm_mm_debug_hole(&mm->head_node, prefix); |
||
805 | |||
3192 | Serge | 806 | drm_mm_for_each_node(entry, mm) { |
6084 | serge | 807 | pr_debug("%s %#llx-%#llx: %llu: used\n", prefix, entry->start, |
808 | entry->start + entry->size, entry->size); |
||
3192 | Serge | 809 | total_used += entry->size; |
4075 | Serge | 810 | total_free += drm_mm_debug_hole(entry, prefix); |
6084 | serge | 811 | } |
3192 | Serge | 812 | total = total_free + total_used; |
813 | |||
6084 | serge | 814 | pr_debug("%s total: %llu, used %llu free %llu\n", prefix, total, |
815 | total_used, total_free); |
||
3192 | Serge | 816 | } |
817 | EXPORT_SYMBOL(drm_mm_debug_table); |
||
818 | |||
819 | #if defined(CONFIG_DEBUG_FS) |
||
6084 | serge | 820 | static u64 drm_mm_dump_hole(struct seq_file *m, struct drm_mm_node *entry) |
3192 | Serge | 821 | { |
6084 | serge | 822 | u64 hole_start, hole_end, hole_size; |
3192 | Serge | 823 | |
3764 | Serge | 824 | if (entry->hole_follows) { |
825 | hole_start = drm_mm_hole_node_start(entry); |
||
826 | hole_end = drm_mm_hole_node_end(entry); |
||
6084 | serge | 827 | hole_size = hole_end - hole_start; |
828 | seq_printf(m, "%#018llx-%#018llx: %llu: free\n", hole_start, |
||
829 | hole_end, hole_size); |
||
3764 | Serge | 830 | return hole_size; |
831 | } |
||
3192 | Serge | 832 | |
3764 | Serge | 833 | return 0; |
834 | } |
||
835 | |||
5060 | serge | 836 | /** |
837 | * drm_mm_dump_table - dump allocator state to a seq_file |
||
838 | * @m: seq_file to dump to |
||
839 | * @mm: drm_mm allocator to dump |
||
840 | */ |
||
3764 | Serge | 841 | int drm_mm_dump_table(struct seq_file *m, struct drm_mm *mm) |
842 | { |
||
843 | struct drm_mm_node *entry; |
||
6084 | serge | 844 | u64 total_used = 0, total_free = 0, total = 0; |
3764 | Serge | 845 | |
846 | total_free += drm_mm_dump_hole(m, &mm->head_node); |
||
847 | |||
3192 | Serge | 848 | drm_mm_for_each_node(entry, mm) { |
6084 | serge | 849 | seq_printf(m, "%#018llx-%#018llx: %llu: used\n", entry->start, |
850 | entry->start + entry->size, entry->size); |
||
3192 | Serge | 851 | total_used += entry->size; |
3764 | Serge | 852 | total_free += drm_mm_dump_hole(m, entry); |
6084 | serge | 853 | } |
3192 | Serge | 854 | total = total_free + total_used; |
855 | |||
6084 | serge | 856 | seq_printf(m, "total: %llu, used %llu free %llu\n", total, |
857 | total_used, total_free); |
||
3192 | Serge | 858 | return 0; |
859 | } |
||
860 | EXPORT_SYMBOL(drm_mm_dump_table); |
||
861 | #endif>>>=>>>=>>>>>>>>> |