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, struct list_head *unwind)
36 {
37 	list_add(&obj->exec_list, unwind);
38 	drm_gem_object_reference(&obj->base);
39 	return drm_mm_scan_add_block(obj->gtt_space);
40 }
41 
42 int
43 i915_gem_evict_something(struct drm_device *dev, int min_size,
44 			 unsigned alignment, bool mappable)
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;
49 	int ret = 0;
50 
51 	i915_gem_retire_requests(dev);
52 
53 	/* Re-check for free space after retiring requests */
54 	if (mappable) {
55 		if (drm_mm_search_free_in_range(&dev_priv->mm.gtt_space,
56 						min_size, alignment, 0,
57 						dev_priv->mm.gtt_mappable_end,
58 						0))
59 			return 0;
60 	} else {
61 		if (drm_mm_search_free(&dev_priv->mm.gtt_space,
62 				       min_size, alignment, 0))
63 			return 0;
64 	}
65 
66 	/*
67 	 * The goal is to evict objects and amalgamate space in LRU order.
68 	 * The oldest idle objects reside on the inactive list, which is in
69 	 * retirement order. The next objects to retire are those on the (per
70 	 * ring) active list that do not have an outstanding flush. Once the
71 	 * hardware reports completion (the seqno is updated after the
72 	 * batchbuffer has been finished) the clean buffer objects would
73 	 * be retired to the inactive list. Any dirty objects would be added
74 	 * to the tail of the flushing list. So after processing the clean
75 	 * active objects we need to emit a MI_FLUSH to retire the flushing
76 	 * list, hence the retirement order of the flushing list is in
77 	 * advance of the dirty objects on the active lists.
78 	 *
79 	 * The retirement sequence is thus:
80 	 *   1. Inactive objects (already retired)
81 	 *   2. Clean active objects
82 	 *   3. Flushing list
83 	 *   4. Dirty active objects.
84 	 *
85 	 * On each list, the oldest objects lie at the HEAD with the freshest
86 	 * object on the TAIL.
87 	 */
88 
89 	INIT_LIST_HEAD(&unwind_list);
90 	if (mappable)
91 		drm_mm_init_scan_with_range(&dev_priv->mm.gtt_space, min_size,
92 					    alignment, 0,
93 					    dev_priv->mm.gtt_mappable_end);
94 	else
95 		drm_mm_init_scan(&dev_priv->mm.gtt_space, min_size, alignment);
96 
97 	/* First see if there is a large enough contiguous idle region... */
98 	list_for_each_entry(obj, &dev_priv->mm.inactive_list, mm_list) {
99 		if (mark_free(obj, &unwind_list))
100 			goto found;
101 	}
102 
103 	/* Now merge in the soon-to-be-expired objects... */
104 	list_for_each_entry(obj, &dev_priv->mm.active_list, mm_list) {
105 		/* Does the object require an outstanding flush? */
106 		if (obj->base.write_domain || obj->pin_count)
107 			continue;
108 
109 		if (mark_free(obj, &unwind_list))
110 			goto found;
111 	}
112 
113 	/* Finally add anything with a pending flush (in order of retirement) */
114 	list_for_each_entry(obj, &dev_priv->mm.flushing_list, mm_list) {
115 		if (obj->pin_count)
116 			continue;
117 
118 		if (mark_free(obj, &unwind_list))
119 			goto found;
120 	}
121 	list_for_each_entry(obj, &dev_priv->mm.active_list, mm_list) {
122 		if (! obj->base.write_domain || obj->pin_count)
123 			continue;
124 
125 		if (mark_free(obj, &unwind_list))
126 			goto found;
127 	}
128 
129 	/* Nothing found, clean up and bail out! */
130 	while (!list_empty(&unwind_list)) {
131 		obj = list_first_entry(&unwind_list,
132 				       struct drm_i915_gem_object,
133 				       exec_list);
134 
135 		ret = drm_mm_scan_remove_block(obj->gtt_space);
136 		BUG_ON(ret);
137 
138 		list_del_init(&obj->exec_list);
139 		drm_gem_object_unreference(&obj->base);
140 	}
141 
142 	/* We expect the caller to unpin, evict all and try again, or give up.
143 	 * So calling i915_gem_evict_everything() is unnecessary.
144 	 */
145 	return -ENOSPC;
146 
147 found:
148 	/* drm_mm doesn't allow any other other operations while
149 	 * scanning, therefore store to be evicted objects on a
150 	 * temporary list. */
151 	INIT_LIST_HEAD(&eviction_list);
152 	while (!list_empty(&unwind_list)) {
153 		obj = list_first_entry(&unwind_list,
154 				       struct drm_i915_gem_object,
155 				       exec_list);
156 		if (drm_mm_scan_remove_block(obj->gtt_space)) {
157 			list_move(&obj->exec_list, &eviction_list);
158 			continue;
159 		}
160 		list_del_init(&obj->exec_list);
161 		drm_gem_object_unreference(&obj->base);
162 	}
163 
164 	/* Unbinding will emit any required flushes */
165 	while (!list_empty(&eviction_list)) {
166 		obj = list_first_entry(&eviction_list,
167 				       struct drm_i915_gem_object,
168 				       exec_list);
169 		if (ret == 0)
170 			ret = i915_gem_object_unbind(obj);
171 
172 		list_del_init(&obj->exec_list);
173 		drm_gem_object_unreference(&obj->base);
174 	}
175 
176 	return ret;
177 }
178 
179 int
180 i915_gem_evict_everything(struct drm_device *dev, bool purgeable_only)
181 {
182 	drm_i915_private_t *dev_priv = dev->dev_private;
183 	int ret;
184 	bool lists_empty;
185 
186 	lists_empty = (list_empty(&dev_priv->mm.inactive_list) &&
187 		       list_empty(&dev_priv->mm.flushing_list) &&
188 		       list_empty(&dev_priv->mm.active_list));
189 	if (lists_empty)
190 		return -ENOSPC;
191 
192 	/* Flush everything (on to the inactive lists) and evict */
193 	ret = i915_gpu_idle(dev);
194 	if (ret)
195 		return ret;
196 
197 	BUG_ON(!list_empty(&dev_priv->mm.flushing_list));
198 
199 	return i915_gem_evict_inactive(dev, purgeable_only);
200 }
201 
202 /** Unbinds all inactive objects. */
203 int
204 i915_gem_evict_inactive(struct drm_device *dev, bool purgeable_only)
205 {
206 	drm_i915_private_t *dev_priv = dev->dev_private;
207 	struct drm_i915_gem_object *obj, *next;
208 
209 	list_for_each_entry_safe(obj, next,
210 				 &dev_priv->mm.inactive_list, mm_list) {
211 		if (!purgeable_only || obj->madv != I915_MADV_WILLNEED) {
212 			int ret = i915_gem_object_unbind(obj);
213 			if (ret)
214 				return ret;
215 		}
216 	}
217 
218 	return 0;
219 }
220