1 /* $NetBSD: i915_gem_evict.c,v 1.2 2018/08/27 04:58:23 riastradh Exp $ */ 2 3 /* 4 * Copyright © 2008-2010 Intel Corporation 5 * 6 * Permission is hereby granted, free of charge, to any person obtaining a 7 * copy of this software and associated documentation files (the "Software"), 8 * to deal in the Software without restriction, including without limitation 9 * the rights to use, copy, modify, merge, publish, distribute, sublicense, 10 * and/or sell copies of the Software, and to permit persons to whom the 11 * Software is furnished to do so, subject to the following conditions: 12 * 13 * The above copyright notice and this permission notice (including the next 14 * paragraph) shall be included in all copies or substantial portions of the 15 * Software. 16 * 17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 20 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 21 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 22 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS 23 * IN THE SOFTWARE. 24 * 25 * Authors: 26 * Eric Anholt <eric@anholt.net> 27 * Chris Wilson <chris@chris-wilson.co.uuk> 28 * 29 */ 30 31 #include <sys/cdefs.h> 32 __KERNEL_RCSID(0, "$NetBSD: i915_gem_evict.c,v 1.2 2018/08/27 04:58:23 riastradh Exp $"); 33 34 #include <drm/drmP.h> 35 #include <drm/i915_drm.h> 36 37 #include "i915_drv.h" 38 #include "intel_drv.h" 39 #include "i915_trace.h" 40 41 static bool 42 mark_free(struct i915_vma *vma, struct list_head *unwind) 43 { 44 if (vma->pin_count) 45 return false; 46 47 if (WARN_ON(!list_empty(&vma->exec_list))) 48 return false; 49 50 list_add(&vma->exec_list, unwind); 51 return drm_mm_scan_add_block(&vma->node); 52 } 53 54 /** 55 * i915_gem_evict_something - Evict vmas to make room for binding a new one 56 * @dev: drm_device 57 * @vm: address space to evict from 58 * @min_size: size of the desired free space 59 * @alignment: alignment constraint of the desired free space 60 * @cache_level: cache_level for the desired space 61 * @start: start (inclusive) of the range from which to evict objects 62 * @end: end (exclusive) of the range from which to evict objects 63 * @flags: additional flags to control the eviction algorithm 64 * 65 * This function will try to evict vmas until a free space satisfying the 66 * requirements is found. Callers must check first whether any such hole exists 67 * already before calling this function. 68 * 69 * This function is used by the object/vma binding code. 70 * 71 * Since this function is only used to free up virtual address space it only 72 * ignores pinned vmas, and not object where the backing storage itself is 73 * pinned. Hence obj->pages_pin_count does not protect against eviction. 74 * 75 * To clarify: This is for freeing up virtual address space, not for freeing 76 * memory in e.g. the shrinker. 77 */ 78 int 79 i915_gem_evict_something(struct drm_device *dev, struct i915_address_space *vm, 80 int min_size, unsigned alignment, unsigned cache_level, 81 unsigned long start, unsigned long end, 82 unsigned flags) 83 { 84 struct list_head eviction_list, unwind_list; 85 struct i915_vma *vma; 86 int ret = 0; 87 int pass = 0; 88 89 trace_i915_gem_evict(dev, min_size, alignment, flags); 90 91 /* 92 * The goal is to evict objects and amalgamate space in LRU order. 93 * The oldest idle objects reside on the inactive list, which is in 94 * retirement order. The next objects to retire are those on the (per 95 * ring) active list that do not have an outstanding flush. Once the 96 * hardware reports completion (the seqno is updated after the 97 * batchbuffer has been finished) the clean buffer objects would 98 * be retired to the inactive list. Any dirty objects would be added 99 * to the tail of the flushing list. So after processing the clean 100 * active objects we need to emit a MI_FLUSH to retire the flushing 101 * list, hence the retirement order of the flushing list is in 102 * advance of the dirty objects on the active lists. 103 * 104 * The retirement sequence is thus: 105 * 1. Inactive objects (already retired) 106 * 2. Clean active objects 107 * 3. Flushing list 108 * 4. Dirty active objects. 109 * 110 * On each list, the oldest objects lie at the HEAD with the freshest 111 * object on the TAIL. 112 */ 113 114 INIT_LIST_HEAD(&unwind_list); 115 if (start != 0 || end != vm->total) { 116 drm_mm_init_scan_with_range(&vm->mm, min_size, 117 alignment, cache_level, 118 start, end); 119 } else 120 drm_mm_init_scan(&vm->mm, min_size, alignment, cache_level); 121 122 search_again: 123 /* First see if there is a large enough contiguous idle region... */ 124 list_for_each_entry(vma, &vm->inactive_list, mm_list) { 125 if (mark_free(vma, &unwind_list)) 126 goto found; 127 } 128 129 if (flags & PIN_NONBLOCK) 130 goto none; 131 132 /* Now merge in the soon-to-be-expired objects... */ 133 list_for_each_entry(vma, &vm->active_list, mm_list) { 134 if (mark_free(vma, &unwind_list)) 135 goto found; 136 } 137 138 none: 139 /* Nothing found, clean up and bail out! */ 140 while (!list_empty(&unwind_list)) { 141 vma = list_first_entry(&unwind_list, 142 struct i915_vma, 143 exec_list); 144 ret = drm_mm_scan_remove_block(&vma->node); 145 BUG_ON(ret); 146 147 list_del_init(&vma->exec_list); 148 } 149 150 /* Can we unpin some objects such as idle hw contents, 151 * or pending flips? 152 */ 153 if (flags & PIN_NONBLOCK) 154 return -ENOSPC; 155 156 /* Only idle the GPU and repeat the search once */ 157 if (pass++ == 0) { 158 ret = i915_gpu_idle(dev); 159 if (ret) 160 return ret; 161 162 i915_gem_retire_requests(dev); 163 goto search_again; 164 } 165 166 /* If we still have pending pageflip completions, drop 167 * back to userspace to give our workqueues time to 168 * acquire our locks and unpin the old scanouts. 169 */ 170 return intel_has_pending_fb_unpin(dev) ? -EAGAIN : -ENOSPC; 171 172 found: 173 /* drm_mm doesn't allow any other other operations while 174 * scanning, therefore store to be evicted objects on a 175 * temporary list. */ 176 INIT_LIST_HEAD(&eviction_list); 177 while (!list_empty(&unwind_list)) { 178 vma = list_first_entry(&unwind_list, 179 struct i915_vma, 180 exec_list); 181 if (drm_mm_scan_remove_block(&vma->node)) { 182 list_move(&vma->exec_list, &eviction_list); 183 drm_gem_object_reference(&vma->obj->base); 184 continue; 185 } 186 list_del_init(&vma->exec_list); 187 } 188 189 /* Unbinding will emit any required flushes */ 190 while (!list_empty(&eviction_list)) { 191 struct drm_gem_object *obj; 192 vma = list_first_entry(&eviction_list, 193 struct i915_vma, 194 exec_list); 195 196 obj = &vma->obj->base; 197 list_del_init(&vma->exec_list); 198 if (ret == 0) 199 ret = i915_vma_unbind(vma); 200 201 drm_gem_object_unreference(obj); 202 } 203 204 return ret; 205 } 206 207 /** 208 * i915_gem_evict_vm - Evict all idle vmas from a vm 209 * @vm: Address space to cleanse 210 * @do_idle: Boolean directing whether to idle first. 211 * 212 * This function evicts all idles vmas from a vm. If all unpinned vmas should be 213 * evicted the @do_idle needs to be set to true. 214 * 215 * This is used by the execbuf code as a last-ditch effort to defragment the 216 * address space. 217 * 218 * To clarify: This is for freeing up virtual address space, not for freeing 219 * memory in e.g. the shrinker. 220 */ 221 int i915_gem_evict_vm(struct i915_address_space *vm, bool do_idle) 222 { 223 struct i915_vma *vma, *next; 224 int ret; 225 226 WARN_ON(!mutex_is_locked(&vm->dev->struct_mutex)); 227 trace_i915_gem_evict_vm(vm); 228 229 if (do_idle) { 230 ret = i915_gpu_idle(vm->dev); 231 if (ret) 232 return ret; 233 234 i915_gem_retire_requests(vm->dev); 235 236 WARN_ON(!list_empty(&vm->active_list)); 237 } 238 239 list_for_each_entry_safe(vma, next, &vm->inactive_list, mm_list) 240 if (vma->pin_count == 0) 241 WARN_ON(i915_vma_unbind(vma)); 242 243 return 0; 244 } 245