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 bool
mark_free(struct i915_vma * vma,struct list_head * unwind)37 mark_free(struct i915_vma *vma, struct list_head *unwind)
38 {
39 if (vma->pin_count)
40 return false;
41
42 if (WARN_ON(!list_empty(&vma->exec_list)))
43 return false;
44
45 list_add(&vma->exec_list, unwind);
46 return drm_mm_scan_add_block(&vma->node);
47 }
48
49 /**
50 * i915_gem_evict_something - Evict vmas to make room for binding a new one
51 * @dev: drm_device
52 * @vm: address space to evict from
53 * @min_size: size of the desired free space
54 * @alignment: alignment constraint of the desired free space
55 * @cache_level: cache_level for the desired space
56 * @start: start (inclusive) of the range from which to evict objects
57 * @end: end (exclusive) of the range from which to evict objects
58 * @flags: additional flags to control the eviction algorithm
59 *
60 * This function will try to evict vmas until a free space satisfying the
61 * requirements is found. Callers must check first whether any such hole exists
62 * already before calling this function.
63 *
64 * This function is used by the object/vma binding code.
65 *
66 * Since this function is only used to free up virtual address space it only
67 * ignores pinned vmas, and not object where the backing storage itself is
68 * pinned. Hence obj->pages_pin_count does not protect against eviction.
69 *
70 * To clarify: This is for freeing up virtual address space, not for freeing
71 * memory in e.g. the shrinker.
72 */
73 int
i915_gem_evict_something(struct drm_device * dev,struct i915_address_space * vm,int min_size,unsigned alignment,unsigned cache_level,unsigned long start,unsigned long end,unsigned flags)74 i915_gem_evict_something(struct drm_device *dev, struct i915_address_space *vm,
75 int min_size, unsigned alignment, unsigned cache_level,
76 unsigned long start, unsigned long end,
77 unsigned flags)
78 {
79 struct list_head eviction_list, unwind_list;
80 struct i915_vma *vma;
81 int ret = 0;
82 int pass = 0;
83
84 trace_i915_gem_evict(dev, min_size, alignment, flags);
85
86 /*
87 * The goal is to evict objects and amalgamate space in LRU order.
88 * The oldest idle objects reside on the inactive list, which is in
89 * retirement order. The next objects to retire are those on the (per
90 * ring) active list that do not have an outstanding flush. Once the
91 * hardware reports completion (the seqno is updated after the
92 * batchbuffer has been finished) the clean buffer objects would
93 * be retired to the inactive list. Any dirty objects would be added
94 * to the tail of the flushing list. So after processing the clean
95 * active objects we need to emit a MI_FLUSH to retire the flushing
96 * list, hence the retirement order of the flushing list is in
97 * advance of the dirty objects on the active lists.
98 *
99 * The retirement sequence is thus:
100 * 1. Inactive objects (already retired)
101 * 2. Clean active objects
102 * 3. Flushing list
103 * 4. Dirty active objects.
104 *
105 * On each list, the oldest objects lie at the HEAD with the freshest
106 * object on the TAIL.
107 */
108
109 INIT_LIST_HEAD(&unwind_list);
110 if (start != 0 || end != vm->total) {
111 drm_mm_init_scan_with_range(&vm->mm, min_size,
112 alignment, cache_level,
113 start, end);
114 } else
115 drm_mm_init_scan(&vm->mm, min_size, alignment, cache_level);
116
117 search_again:
118 /* First see if there is a large enough contiguous idle region... */
119 list_for_each_entry(vma, &vm->inactive_list, mm_list) {
120 if (mark_free(vma, &unwind_list))
121 goto found;
122 }
123
124 if (flags & PIN_NONBLOCK)
125 goto none;
126
127 /* Now merge in the soon-to-be-expired objects... */
128 list_for_each_entry(vma, &vm->active_list, mm_list) {
129 if (mark_free(vma, &unwind_list))
130 goto found;
131 }
132
133 none:
134 /* Nothing found, clean up and bail out! */
135 while (!list_empty(&unwind_list)) {
136 vma = list_first_entry(&unwind_list,
137 struct i915_vma,
138 exec_list);
139 ret = drm_mm_scan_remove_block(&vma->node);
140 BUG_ON(ret);
141
142 list_del_init(&vma->exec_list);
143 }
144
145 /* Can we unpin some objects such as idle hw contents,
146 * or pending flips?
147 */
148 if (flags & PIN_NONBLOCK)
149 return -ENOSPC;
150
151 /* Only idle the GPU and repeat the search once */
152 if (pass++ == 0) {
153 ret = i915_gpu_idle(dev);
154 if (ret)
155 return ret;
156
157 i915_gem_retire_requests(dev);
158 goto search_again;
159 }
160
161 /* If we still have pending pageflip completions, drop
162 * back to userspace to give our workqueues time to
163 * acquire our locks and unpin the old scanouts.
164 */
165 return intel_has_pending_fb_unpin(dev) ? -EAGAIN : -ENOSPC;
166
167 found:
168 /* drm_mm doesn't allow any other other operations while
169 * scanning, therefore store to be evicted objects on a
170 * temporary list. */
171 INIT_LIST_HEAD(&eviction_list);
172 while (!list_empty(&unwind_list)) {
173 vma = list_first_entry(&unwind_list,
174 struct i915_vma,
175 exec_list);
176 if (drm_mm_scan_remove_block(&vma->node)) {
177 list_move(&vma->exec_list, &eviction_list);
178 drm_gem_object_reference(&vma->obj->base);
179 continue;
180 }
181 list_del_init(&vma->exec_list);
182 }
183
184 /* Unbinding will emit any required flushes */
185 while (!list_empty(&eviction_list)) {
186 struct drm_gem_object *obj;
187 vma = list_first_entry(&eviction_list,
188 struct i915_vma,
189 exec_list);
190
191 obj = &vma->obj->base;
192 list_del_init(&vma->exec_list);
193 if (ret == 0)
194 ret = i915_vma_unbind(vma);
195
196 drm_gem_object_unreference(obj);
197 }
198
199 return ret;
200 }
201
202 /**
203 * i915_gem_evict_vm - Evict all idle vmas from a vm
204 * @vm: Address space to cleanse
205 * @do_idle: Boolean directing whether to idle first.
206 *
207 * This function evicts all idles vmas from a vm. If all unpinned vmas should be
208 * evicted the @do_idle needs to be set to true.
209 *
210 * This is used by the execbuf code as a last-ditch effort to defragment the
211 * address space.
212 *
213 * To clarify: This is for freeing up virtual address space, not for freeing
214 * memory in e.g. the shrinker.
215 */
i915_gem_evict_vm(struct i915_address_space * vm,bool do_idle)216 int i915_gem_evict_vm(struct i915_address_space *vm, bool do_idle)
217 {
218 struct i915_vma *vma, *next;
219 int ret;
220
221 WARN_ON(!mutex_is_locked(&vm->dev->struct_mutex));
222 trace_i915_gem_evict_vm(vm);
223
224 if (do_idle) {
225 ret = i915_gpu_idle(vm->dev);
226 if (ret)
227 return ret;
228
229 i915_gem_retire_requests(vm->dev);
230
231 WARN_ON(!list_empty(&vm->active_list));
232 }
233
234 list_for_each_entry_safe(vma, next, &vm->inactive_list, mm_list)
235 if (vma->pin_count == 0)
236 WARN_ON(i915_vma_unbind(vma));
237
238 return 0;
239 }
240