xref: /openbmc/linux/drivers/gpu/drm/i915/i915_gem_evict.c (revision baa7eb025ab14f3cba2e35c0a8648f9c9f01d24f)
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 "drmP.h"
30 #include "drm.h"
31 #include "i915_drv.h"
32 #include "i915_drm.h"
33 
34 static bool
35 mark_free(struct drm_i915_gem_object *obj_priv,
36 	   struct list_head *unwind)
37 {
38 	list_add(&obj_priv->evict_list, unwind);
39 	drm_gem_object_reference(&obj_priv->base);
40 	return drm_mm_scan_add_block(obj_priv->gtt_space);
41 }
42 
43 int
44 i915_gem_evict_something(struct drm_device *dev, int min_size, unsigned alignment)
45 {
46 	drm_i915_private_t *dev_priv = dev->dev_private;
47 	struct list_head eviction_list, unwind_list;
48 	struct drm_i915_gem_object *obj_priv;
49 	int ret = 0;
50 
51 	i915_gem_retire_requests(dev);
52 
53 	/* Re-check for free space after retiring requests */
54 	if (drm_mm_search_free(&dev_priv->mm.gtt_space,
55 			       min_size, alignment, 0))
56 		return 0;
57 
58 	/*
59 	 * The goal is to evict objects and amalgamate space in LRU order.
60 	 * The oldest idle objects reside on the inactive list, which is in
61 	 * retirement order. The next objects to retire are those on the (per
62 	 * ring) active list that do not have an outstanding flush. Once the
63 	 * hardware reports completion (the seqno is updated after the
64 	 * batchbuffer has been finished) the clean buffer objects would
65 	 * be retired to the inactive list. Any dirty objects would be added
66 	 * to the tail of the flushing list. So after processing the clean
67 	 * active objects we need to emit a MI_FLUSH to retire the flushing
68 	 * list, hence the retirement order of the flushing list is in
69 	 * advance of the dirty objects on the active lists.
70 	 *
71 	 * The retirement sequence is thus:
72 	 *   1. Inactive objects (already retired)
73 	 *   2. Clean active objects
74 	 *   3. Flushing list
75 	 *   4. Dirty active objects.
76 	 *
77 	 * On each list, the oldest objects lie at the HEAD with the freshest
78 	 * object on the TAIL.
79 	 */
80 
81 	INIT_LIST_HEAD(&unwind_list);
82 	drm_mm_init_scan(&dev_priv->mm.gtt_space, min_size, alignment);
83 
84 	/* First see if there is a large enough contiguous idle region... */
85 	list_for_each_entry(obj_priv, &dev_priv->mm.inactive_list, mm_list) {
86 		if (mark_free(obj_priv, &unwind_list))
87 			goto found;
88 	}
89 
90 	/* Now merge in the soon-to-be-expired objects... */
91 	list_for_each_entry(obj_priv, &dev_priv->mm.active_list, mm_list) {
92 		/* Does the object require an outstanding flush? */
93 		if (obj_priv->base.write_domain || obj_priv->pin_count)
94 			continue;
95 
96 		if (mark_free(obj_priv, &unwind_list))
97 			goto found;
98 	}
99 
100 	/* Finally add anything with a pending flush (in order of retirement) */
101 	list_for_each_entry(obj_priv, &dev_priv->mm.flushing_list, mm_list) {
102 		if (obj_priv->pin_count)
103 			continue;
104 
105 		if (mark_free(obj_priv, &unwind_list))
106 			goto found;
107 	}
108 	list_for_each_entry(obj_priv, &dev_priv->mm.active_list, mm_list) {
109 		if (! obj_priv->base.write_domain || obj_priv->pin_count)
110 			continue;
111 
112 		if (mark_free(obj_priv, &unwind_list))
113 			goto found;
114 	}
115 
116 	/* Nothing found, clean up and bail out! */
117 	list_for_each_entry(obj_priv, &unwind_list, evict_list) {
118 		ret = drm_mm_scan_remove_block(obj_priv->gtt_space);
119 		BUG_ON(ret);
120 		drm_gem_object_unreference(&obj_priv->base);
121 	}
122 
123 	/* We expect the caller to unpin, evict all and try again, or give up.
124 	 * So calling i915_gem_evict_everything() is unnecessary.
125 	 */
126 	return -ENOSPC;
127 
128 found:
129 	/* drm_mm doesn't allow any other other operations while
130 	 * scanning, therefore store to be evicted objects on a
131 	 * temporary list. */
132 	INIT_LIST_HEAD(&eviction_list);
133 	while (!list_empty(&unwind_list)) {
134 		obj_priv = list_first_entry(&unwind_list,
135 					    struct drm_i915_gem_object,
136 					    evict_list);
137 		if (drm_mm_scan_remove_block(obj_priv->gtt_space)) {
138 			list_move(&obj_priv->evict_list, &eviction_list);
139 			continue;
140 		}
141 		list_del(&obj_priv->evict_list);
142 		drm_gem_object_unreference(&obj_priv->base);
143 	}
144 
145 	/* Unbinding will emit any required flushes */
146 	while (!list_empty(&eviction_list)) {
147 		obj_priv = list_first_entry(&eviction_list,
148 					    struct drm_i915_gem_object,
149 					    evict_list);
150 		if (ret == 0)
151 			ret = i915_gem_object_unbind(&obj_priv->base);
152 		list_del(&obj_priv->evict_list);
153 		drm_gem_object_unreference(&obj_priv->base);
154 	}
155 
156 	return ret;
157 }
158 
159 int
160 i915_gem_evict_everything(struct drm_device *dev)
161 {
162 	drm_i915_private_t *dev_priv = dev->dev_private;
163 	int ret;
164 	bool lists_empty;
165 
166 	lists_empty = (list_empty(&dev_priv->mm.inactive_list) &&
167 		       list_empty(&dev_priv->mm.flushing_list) &&
168 		       list_empty(&dev_priv->mm.active_list));
169 	if (lists_empty)
170 		return -ENOSPC;
171 
172 	/* Flush everything (on to the inactive lists) and evict */
173 	ret = i915_gpu_idle(dev);
174 	if (ret)
175 		return ret;
176 
177 	BUG_ON(!list_empty(&dev_priv->mm.flushing_list));
178 
179 	ret = i915_gem_evict_inactive(dev);
180 	if (ret)
181 		return ret;
182 
183 	lists_empty = (list_empty(&dev_priv->mm.inactive_list) &&
184 		       list_empty(&dev_priv->mm.flushing_list) &&
185 		       list_empty(&dev_priv->mm.active_list));
186 	BUG_ON(!lists_empty);
187 
188 	return 0;
189 }
190 
191 /** Unbinds all inactive objects. */
192 int
193 i915_gem_evict_inactive(struct drm_device *dev)
194 {
195 	drm_i915_private_t *dev_priv = dev->dev_private;
196 
197 	while (!list_empty(&dev_priv->mm.inactive_list)) {
198 		struct drm_gem_object *obj;
199 		int ret;
200 
201 		obj = &list_first_entry(&dev_priv->mm.inactive_list,
202 					struct drm_i915_gem_object,
203 					mm_list)->base;
204 
205 		ret = i915_gem_object_unbind(obj);
206 		if (ret != 0) {
207 			DRM_ERROR("Error unbinding object: %d\n", ret);
208 			return ret;
209 		}
210 	}
211 
212 	return 0;
213 }
214