1 /* 2 * Copyright © 2008-2010 Intel Corporation 3 * 4 * Permission is hereby granted, free of charge, to any person obtaining a 5 * copy of this software and associated documentation files (the "Software"), 6 * to deal in the Software without restriction, including without limitation 7 * the rights to use, copy, modify, merge, publish, distribute, sublicense, 8 * and/or sell copies of the Software, and to permit persons to whom the 9 * Software is furnished to do so, subject to the following conditions: 10 * 11 * The above copyright notice and this permission notice (including the next 12 * paragraph) shall be included in all copies or substantial portions of the 13 * Software. 14 * 15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS 21 * IN THE SOFTWARE. 22 * 23 * Authors: 24 * Eric Anholt <eric@anholt.net> 25 * Chris Wilson <chris@chris-wilson.co.uuk> 26 * 27 */ 28 29 #include <drm/drmP.h> 30 #include <drm/i915_drm.h> 31 32 #include "i915_drv.h" 33 #include "intel_drv.h" 34 #include "i915_trace.h" 35 36 static int switch_to_pinned_context(struct drm_i915_private *dev_priv) 37 { 38 struct intel_engine_cs *engine; 39 40 if (i915.enable_execlists) 41 return 0; 42 43 for_each_engine(engine, dev_priv) { 44 struct drm_i915_gem_request *req; 45 int ret; 46 47 if (engine->last_context == NULL) 48 continue; 49 50 if (engine->last_context == dev_priv->kernel_context) 51 continue; 52 53 req = i915_gem_request_alloc(engine, dev_priv->kernel_context); 54 if (IS_ERR(req)) 55 return PTR_ERR(req); 56 57 ret = i915_switch_context(req); 58 i915_add_request_no_flush(req); 59 if (ret) 60 return ret; 61 } 62 63 return 0; 64 } 65 66 67 static bool 68 mark_free(struct i915_vma *vma, struct list_head *unwind) 69 { 70 if (vma->pin_count) 71 return false; 72 73 if (WARN_ON(!list_empty(&vma->exec_list))) 74 return false; 75 76 list_add(&vma->exec_list, unwind); 77 return drm_mm_scan_add_block(&vma->node); 78 } 79 80 /** 81 * i915_gem_evict_something - Evict vmas to make room for binding a new one 82 * @dev: drm_device 83 * @vm: address space to evict from 84 * @min_size: size of the desired free space 85 * @alignment: alignment constraint of the desired free space 86 * @cache_level: cache_level for the desired space 87 * @start: start (inclusive) of the range from which to evict objects 88 * @end: end (exclusive) of the range from which to evict objects 89 * @flags: additional flags to control the eviction algorithm 90 * 91 * This function will try to evict vmas until a free space satisfying the 92 * requirements is found. Callers must check first whether any such hole exists 93 * already before calling this function. 94 * 95 * This function is used by the object/vma binding code. 96 * 97 * Since this function is only used to free up virtual address space it only 98 * ignores pinned vmas, and not object where the backing storage itself is 99 * pinned. Hence obj->pages_pin_count does not protect against eviction. 100 * 101 * To clarify: This is for freeing up virtual address space, not for freeing 102 * memory in e.g. the shrinker. 103 */ 104 int 105 i915_gem_evict_something(struct drm_device *dev, struct i915_address_space *vm, 106 int min_size, unsigned alignment, unsigned cache_level, 107 unsigned long start, unsigned long end, 108 unsigned flags) 109 { 110 struct list_head eviction_list, unwind_list; 111 struct i915_vma *vma; 112 int ret = 0; 113 int pass = 0; 114 115 trace_i915_gem_evict(dev, min_size, alignment, flags); 116 117 /* 118 * The goal is to evict objects and amalgamate space in LRU order. 119 * The oldest idle objects reside on the inactive list, which is in 120 * retirement order. The next objects to retire are those on the (per 121 * ring) active list that do not have an outstanding flush. Once the 122 * hardware reports completion (the seqno is updated after the 123 * batchbuffer has been finished) the clean buffer objects would 124 * be retired to the inactive list. Any dirty objects would be added 125 * to the tail of the flushing list. So after processing the clean 126 * active objects we need to emit a MI_FLUSH to retire the flushing 127 * list, hence the retirement order of the flushing list is in 128 * advance of the dirty objects on the active lists. 129 * 130 * The retirement sequence is thus: 131 * 1. Inactive objects (already retired) 132 * 2. Clean active objects 133 * 3. Flushing list 134 * 4. Dirty active objects. 135 * 136 * On each list, the oldest objects lie at the HEAD with the freshest 137 * object on the TAIL. 138 */ 139 140 INIT_LIST_HEAD(&unwind_list); 141 if (start != 0 || end != vm->total) { 142 drm_mm_init_scan_with_range(&vm->mm, min_size, 143 alignment, cache_level, 144 start, end); 145 } else 146 drm_mm_init_scan(&vm->mm, min_size, alignment, cache_level); 147 148 search_again: 149 /* First see if there is a large enough contiguous idle region... */ 150 list_for_each_entry(vma, &vm->inactive_list, vm_link) { 151 if (mark_free(vma, &unwind_list)) 152 goto found; 153 } 154 155 if (flags & PIN_NONBLOCK) 156 goto none; 157 158 /* Now merge in the soon-to-be-expired objects... */ 159 list_for_each_entry(vma, &vm->active_list, vm_link) { 160 if (mark_free(vma, &unwind_list)) 161 goto found; 162 } 163 164 none: 165 /* Nothing found, clean up and bail out! */ 166 while (!list_empty(&unwind_list)) { 167 vma = list_first_entry(&unwind_list, 168 struct i915_vma, 169 exec_list); 170 ret = drm_mm_scan_remove_block(&vma->node); 171 BUG_ON(ret); 172 173 list_del_init(&vma->exec_list); 174 } 175 176 /* Can we unpin some objects such as idle hw contents, 177 * or pending flips? 178 */ 179 if (flags & PIN_NONBLOCK) 180 return -ENOSPC; 181 182 /* Only idle the GPU and repeat the search once */ 183 if (pass++ == 0) { 184 struct drm_i915_private *dev_priv = to_i915(dev); 185 186 if (i915_is_ggtt(vm)) { 187 ret = switch_to_pinned_context(dev_priv); 188 if (ret) 189 return ret; 190 } 191 192 ret = i915_gem_wait_for_idle(dev_priv); 193 if (ret) 194 return ret; 195 196 i915_gem_retire_requests(dev_priv); 197 goto search_again; 198 } 199 200 /* If we still have pending pageflip completions, drop 201 * back to userspace to give our workqueues time to 202 * acquire our locks and unpin the old scanouts. 203 */ 204 return intel_has_pending_fb_unpin(dev) ? -EAGAIN : -ENOSPC; 205 206 found: 207 /* drm_mm doesn't allow any other other operations while 208 * scanning, therefore store to be evicted objects on a 209 * temporary list. */ 210 INIT_LIST_HEAD(&eviction_list); 211 while (!list_empty(&unwind_list)) { 212 vma = list_first_entry(&unwind_list, 213 struct i915_vma, 214 exec_list); 215 if (drm_mm_scan_remove_block(&vma->node)) { 216 list_move(&vma->exec_list, &eviction_list); 217 drm_gem_object_reference(&vma->obj->base); 218 continue; 219 } 220 list_del_init(&vma->exec_list); 221 } 222 223 /* Unbinding will emit any required flushes */ 224 while (!list_empty(&eviction_list)) { 225 struct drm_gem_object *obj; 226 vma = list_first_entry(&eviction_list, 227 struct i915_vma, 228 exec_list); 229 230 obj = &vma->obj->base; 231 list_del_init(&vma->exec_list); 232 if (ret == 0) 233 ret = i915_vma_unbind(vma); 234 235 drm_gem_object_unreference(obj); 236 } 237 238 return ret; 239 } 240 241 int 242 i915_gem_evict_for_vma(struct i915_vma *target) 243 { 244 struct drm_mm_node *node, *next; 245 246 list_for_each_entry_safe(node, next, 247 &target->vm->mm.head_node.node_list, 248 node_list) { 249 struct i915_vma *vma; 250 int ret; 251 252 if (node->start + node->size <= target->node.start) 253 continue; 254 if (node->start >= target->node.start + target->node.size) 255 break; 256 257 vma = container_of(node, typeof(*vma), node); 258 259 if (vma->pin_count) { 260 if (!vma->exec_entry || (vma->pin_count > 1)) 261 /* Object is pinned for some other use */ 262 return -EBUSY; 263 264 /* We need to evict a buffer in the same batch */ 265 if (vma->exec_entry->flags & EXEC_OBJECT_PINNED) 266 /* Overlapping fixed objects in the same batch */ 267 return -EINVAL; 268 269 return -ENOSPC; 270 } 271 272 ret = i915_vma_unbind(vma); 273 if (ret) 274 return ret; 275 } 276 277 return 0; 278 } 279 280 /** 281 * i915_gem_evict_vm - Evict all idle vmas from a vm 282 * @vm: Address space to cleanse 283 * @do_idle: Boolean directing whether to idle first. 284 * 285 * This function evicts all idles vmas from a vm. If all unpinned vmas should be 286 * evicted the @do_idle needs to be set to true. 287 * 288 * This is used by the execbuf code as a last-ditch effort to defragment the 289 * address space. 290 * 291 * To clarify: This is for freeing up virtual address space, not for freeing 292 * memory in e.g. the shrinker. 293 */ 294 int i915_gem_evict_vm(struct i915_address_space *vm, bool do_idle) 295 { 296 struct i915_vma *vma, *next; 297 int ret; 298 299 WARN_ON(!mutex_is_locked(&vm->dev->struct_mutex)); 300 trace_i915_gem_evict_vm(vm); 301 302 if (do_idle) { 303 struct drm_i915_private *dev_priv = to_i915(vm->dev); 304 305 if (i915_is_ggtt(vm)) { 306 ret = switch_to_pinned_context(dev_priv); 307 if (ret) 308 return ret; 309 } 310 311 ret = i915_gem_wait_for_idle(dev_priv); 312 if (ret) 313 return ret; 314 315 i915_gem_retire_requests(dev_priv); 316 317 WARN_ON(!list_empty(&vm->active_list)); 318 } 319 320 list_for_each_entry_safe(vma, next, &vm->inactive_list, vm_link) 321 if (vma->pin_count == 0) 322 WARN_ON(i915_vma_unbind(vma)); 323 324 return 0; 325 } 326