1 /* $OpenBSD: i915_gem_evict.c,v 1.7 2015/09/23 23:12:12 kettenis Exp $ */ 2 /* 3 * Copyright © 2008-2010 Intel Corporation 4 * 5 * Permission is hereby granted, free of charge, to any person obtaining a 6 * copy of this software and associated documentation files (the "Software"), 7 * to deal in the Software without restriction, including without limitation 8 * the rights to use, copy, modify, merge, publish, distribute, sublicense, 9 * and/or sell copies of the Software, and to permit persons to whom the 10 * Software is furnished to do so, subject to the following conditions: 11 * 12 * The above copyright notice and this permission notice (including the next 13 * paragraph) shall be included in all copies or substantial portions of the 14 * Software. 15 * 16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 21 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS 22 * IN THE SOFTWARE. 23 * 24 * Authors: 25 * Eric Anholt <eric@anholt.net> 26 * Chris Wilson <chris@chris-wilson.co.uuk> 27 * 28 */ 29 30 #include <dev/pci/drm/drmP.h> 31 #include <dev/pci/drm/i915_drm.h> 32 33 #include "i915_drv.h" 34 #include "intel_drv.h" 35 #include "i915_trace.h" 36 37 static bool 38 mark_free(struct i915_vma *vma, struct list_head *unwind) 39 { 40 if (vma->obj->pin_count) 41 return false; 42 43 if (WARN_ON(!list_empty(&vma->exec_list))) 44 return false; 45 46 list_add(&vma->exec_list, unwind); 47 return drm_mm_scan_add_block(&vma->node); 48 } 49 50 int 51 i915_gem_evict_something(struct drm_device *dev, struct i915_address_space *vm, 52 int min_size, unsigned alignment, unsigned cache_level, 53 bool mappable, bool nonblocking) 54 { 55 drm_i915_private_t *dev_priv = dev->dev_private; 56 struct list_head eviction_list, unwind_list; 57 struct i915_vma *vma; 58 int ret = 0; 59 int pass = 0; 60 61 trace_i915_gem_evict(dev, min_size, alignment, mappable); 62 63 /* 64 * The goal is to evict objects and amalgamate space in LRU order. 65 * The oldest idle objects reside on the inactive list, which is in 66 * retirement order. The next objects to retire are those on the (per 67 * ring) active list that do not have an outstanding flush. Once the 68 * hardware reports completion (the seqno is updated after the 69 * batchbuffer has been finished) the clean buffer objects would 70 * be retired to the inactive list. Any dirty objects would be added 71 * to the tail of the flushing list. So after processing the clean 72 * active objects we need to emit a MI_FLUSH to retire the flushing 73 * list, hence the retirement order of the flushing list is in 74 * advance of the dirty objects on the active lists. 75 * 76 * The retirement sequence is thus: 77 * 1. Inactive objects (already retired) 78 * 2. Clean active objects 79 * 3. Flushing list 80 * 4. Dirty active objects. 81 * 82 * On each list, the oldest objects lie at the HEAD with the freshest 83 * object on the TAIL. 84 */ 85 86 INIT_LIST_HEAD(&unwind_list); 87 if (mappable) { 88 BUG_ON(!i915_is_ggtt(vm)); 89 drm_mm_init_scan_with_range(&vm->mm, min_size, 90 alignment, cache_level, 0, 91 dev_priv->gtt.mappable_end); 92 } else 93 drm_mm_init_scan(&vm->mm, min_size, alignment, cache_level); 94 95 search_again: 96 /* First see if there is a large enough contiguous idle region... */ 97 list_for_each_entry(vma, &vm->inactive_list, mm_list) { 98 if (mark_free(vma, &unwind_list)) 99 goto found; 100 } 101 102 if (nonblocking) 103 goto none; 104 105 /* Now merge in the soon-to-be-expired objects... */ 106 list_for_each_entry(vma, &vm->active_list, mm_list) { 107 if (mark_free(vma, &unwind_list)) 108 goto found; 109 } 110 111 none: 112 /* Nothing found, clean up and bail out! */ 113 while (!list_empty(&unwind_list)) { 114 vma = list_first_entry(&unwind_list, 115 struct i915_vma, 116 exec_list); 117 ret = drm_mm_scan_remove_block(&vma->node); 118 BUG_ON(ret); 119 120 list_del_init(&vma->exec_list); 121 } 122 123 /* Can we unpin some objects such as idle hw contents, 124 * or pending flips? 125 */ 126 if (nonblocking) 127 return -ENOSPC; 128 129 /* Only idle the GPU and repeat the search once */ 130 if (pass++ == 0) { 131 ret = i915_gpu_idle(dev); 132 if (ret) 133 return ret; 134 135 i915_gem_retire_requests(dev); 136 goto search_again; 137 } 138 139 /* If we still have pending pageflip completions, drop 140 * back to userspace to give our workqueues time to 141 * acquire our locks and unpin the old scanouts. 142 */ 143 return intel_has_pending_fb_unpin(dev) ? -EAGAIN : -ENOSPC; 144 145 found: 146 /* drm_mm doesn't allow any other other operations while 147 * scanning, therefore store to be evicted objects on a 148 * temporary list. */ 149 INIT_LIST_HEAD(&eviction_list); 150 while (!list_empty(&unwind_list)) { 151 vma = list_first_entry(&unwind_list, 152 struct i915_vma, 153 exec_list); 154 if (drm_mm_scan_remove_block(&vma->node)) { 155 list_move(&vma->exec_list, &eviction_list); 156 drm_gem_object_reference(&vma->obj->base); 157 continue; 158 } 159 list_del_init(&vma->exec_list); 160 } 161 162 /* Unbinding will emit any required flushes */ 163 while (!list_empty(&eviction_list)) { 164 struct drm_gem_object *obj; 165 vma = list_first_entry(&eviction_list, 166 struct i915_vma, 167 exec_list); 168 169 obj = &vma->obj->base; 170 list_del_init(&vma->exec_list); 171 if (ret == 0) 172 ret = i915_vma_unbind(vma); 173 174 drm_gem_object_unreference(obj); 175 } 176 177 return ret; 178 } 179 180 /** 181 * i915_gem_evict_vm - Try to free up VM space 182 * 183 * @vm: Address space to evict from 184 * @do_idle: Boolean directing whether to idle first. 185 * 186 * VM eviction is about freeing up virtual address space. If one wants fine 187 * grained eviction, they should see evict something for more details. In terms 188 * of freeing up actual system memory, this function may not accomplish the 189 * desired result. An object may be shared in multiple address space, and this 190 * function will not assert those objects be freed. 191 * 192 * Using do_idle will result in a more complete eviction because it retires, and 193 * inactivates current BOs. 194 */ 195 int i915_gem_evict_vm(struct i915_address_space *vm, bool do_idle) 196 { 197 struct i915_vma *vma, *next; 198 int ret; 199 200 trace_i915_gem_evict_vm(vm); 201 202 if (do_idle) { 203 ret = i915_gpu_idle(vm->dev); 204 if (ret) 205 return ret; 206 207 i915_gem_retire_requests(vm->dev); 208 } 209 210 list_for_each_entry_safe(vma, next, &vm->inactive_list, mm_list) 211 if (vma->obj->pin_count == 0) 212 WARN_ON(i915_vma_unbind(vma)); 213 214 return 0; 215 } 216 217 int 218 i915_gem_evict_everything(struct drm_device *dev) 219 { 220 drm_i915_private_t *dev_priv = dev->dev_private; 221 struct i915_address_space *vm; 222 bool lists_empty = true; 223 int ret; 224 225 list_for_each_entry(vm, &dev_priv->vm_list, global_link) { 226 lists_empty = (list_empty(&vm->inactive_list) && 227 list_empty(&vm->active_list)); 228 if (!lists_empty) 229 lists_empty = false; 230 } 231 232 if (lists_empty) 233 return -ENOSPC; 234 235 trace_i915_gem_evict_everything(dev); 236 237 /* The gpu_idle will flush everything in the write domain to the 238 * active list. Then we must move everything off the active list 239 * with retire requests. 240 */ 241 ret = i915_gpu_idle(dev); 242 if (ret) 243 return ret; 244 245 i915_gem_retire_requests(dev); 246 247 /* Having flushed everything, unbind() should never raise an error */ 248 list_for_each_entry(vm, &dev_priv->vm_list, global_link) 249 WARN_ON(i915_gem_evict_vm(vm, false)); 250 251 return 0; 252 } 253