xref: /dragonfly/sys/dev/drm/i915/i915_gem_evict.c (revision e98bdfd3)
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
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
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  */
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 
241 /**
242  * i915_gem_evict_everything - Try to evict all objects
243  * @dev: Device to evict objects for
244  *
245  * This functions tries to evict all gem objects from all address spaces. Used
246  * by the shrinker as a last-ditch effort and for suspend, before releasing the
247  * backing storage of all unbound objects.
248  */
249 int
250 i915_gem_evict_everything(struct drm_device *dev)
251 {
252 	struct drm_i915_private *dev_priv = dev->dev_private;
253 	struct i915_address_space *vm, *v;
254 	bool lists_empty = true;
255 	int ret;
256 
257 	list_for_each_entry(vm, &dev_priv->vm_list, global_link) {
258 		lists_empty = (list_empty(&vm->inactive_list) &&
259 			       list_empty(&vm->active_list));
260 		if (!lists_empty)
261 			lists_empty = false;
262 	}
263 
264 	if (lists_empty)
265 		return -ENOSPC;
266 
267 	trace_i915_gem_evict_everything(dev);
268 
269 	/* The gpu_idle will flush everything in the write domain to the
270 	 * active list. Then we must move everything off the active list
271 	 * with retire requests.
272 	 */
273 	ret = i915_gpu_idle(dev);
274 	if (ret)
275 		return ret;
276 
277 	i915_gem_retire_requests(dev);
278 
279 	/* Having flushed everything, unbind() should never raise an error */
280 	list_for_each_entry_safe(vm, v, &dev_priv->vm_list, global_link)
281 		WARN_ON(i915_gem_evict_vm(vm, false));
282 
283 	return 0;
284 }
285