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 #include "i915_trace.h"
34 
35 static bool
36 mark_free(struct drm_i915_gem_object *obj, struct list_head *unwind)
37 {
38 	list_add(&obj->exec_list, unwind);
39 	drm_gem_object_reference(&obj->base);
40 	return drm_mm_scan_add_block(obj->gtt_space);
41 }
42 
43 int
44 i915_gem_evict_something(struct drm_device *dev, int min_size,
45 			 unsigned alignment, bool mappable)
46 {
47 	drm_i915_private_t *dev_priv = dev->dev_private;
48 	struct list_head eviction_list, unwind_list;
49 	struct drm_i915_gem_object *obj;
50 	int ret = 0;
51 
52 	i915_gem_retire_requests(dev);
53 
54 	/* Re-check for free space after retiring requests */
55 	if (mappable) {
56 		if (drm_mm_search_free_in_range(&dev_priv->mm.gtt_space,
57 						min_size, alignment, 0,
58 						dev_priv->mm.gtt_mappable_end,
59 						0))
60 			return 0;
61 	} else {
62 		if (drm_mm_search_free(&dev_priv->mm.gtt_space,
63 				       min_size, alignment, 0))
64 			return 0;
65 	}
66 
67 	trace_i915_gem_evict(dev, min_size, alignment, mappable);
68 
69 	/*
70 	 * The goal is to evict objects and amalgamate space in LRU order.
71 	 * The oldest idle objects reside on the inactive list, which is in
72 	 * retirement order. The next objects to retire are those on the (per
73 	 * ring) active list that do not have an outstanding flush. Once the
74 	 * hardware reports completion (the seqno is updated after the
75 	 * batchbuffer has been finished) the clean buffer objects would
76 	 * be retired to the inactive list. Any dirty objects would be added
77 	 * to the tail of the flushing list. So after processing the clean
78 	 * active objects we need to emit a MI_FLUSH to retire the flushing
79 	 * list, hence the retirement order of the flushing list is in
80 	 * advance of the dirty objects on the active lists.
81 	 *
82 	 * The retirement sequence is thus:
83 	 *   1. Inactive objects (already retired)
84 	 *   2. Clean active objects
85 	 *   3. Flushing list
86 	 *   4. Dirty active objects.
87 	 *
88 	 * On each list, the oldest objects lie at the HEAD with the freshest
89 	 * object on the TAIL.
90 	 */
91 
92 	INIT_LIST_HEAD(&unwind_list);
93 	if (mappable)
94 		drm_mm_init_scan_with_range(&dev_priv->mm.gtt_space, min_size,
95 					    alignment, 0,
96 					    dev_priv->mm.gtt_mappable_end);
97 	else
98 		drm_mm_init_scan(&dev_priv->mm.gtt_space, min_size, alignment);
99 
100 	/* First see if there is a large enough contiguous idle region... */
101 	list_for_each_entry(obj, &dev_priv->mm.inactive_list, mm_list) {
102 		if (mark_free(obj, &unwind_list))
103 			goto found;
104 	}
105 
106 	/* Now merge in the soon-to-be-expired objects... */
107 	list_for_each_entry(obj, &dev_priv->mm.active_list, mm_list) {
108 		/* Does the object require an outstanding flush? */
109 		if (obj->base.write_domain || obj->pin_count)
110 			continue;
111 
112 		if (mark_free(obj, &unwind_list))
113 			goto found;
114 	}
115 
116 	/* Finally add anything with a pending flush (in order of retirement) */
117 	list_for_each_entry(obj, &dev_priv->mm.flushing_list, mm_list) {
118 		if (obj->pin_count)
119 			continue;
120 
121 		if (mark_free(obj, &unwind_list))
122 			goto found;
123 	}
124 	list_for_each_entry(obj, &dev_priv->mm.active_list, mm_list) {
125 		if (! obj->base.write_domain || obj->pin_count)
126 			continue;
127 
128 		if (mark_free(obj, &unwind_list))
129 			goto found;
130 	}
131 
132 	/* Nothing found, clean up and bail out! */
133 	while (!list_empty(&unwind_list)) {
134 		obj = list_first_entry(&unwind_list,
135 				       struct drm_i915_gem_object,
136 				       exec_list);
137 
138 		ret = drm_mm_scan_remove_block(obj->gtt_space);
139 		BUG_ON(ret);
140 
141 		list_del_init(&obj->exec_list);
142 		drm_gem_object_unreference(&obj->base);
143 	}
144 
145 	/* We expect the caller to unpin, evict all and try again, or give up.
146 	 * So calling i915_gem_evict_everything() is unnecessary.
147 	 */
148 	return -ENOSPC;
149 
150 found:
151 	/* drm_mm doesn't allow any other other operations while
152 	 * scanning, therefore store to be evicted objects on a
153 	 * temporary list. */
154 	INIT_LIST_HEAD(&eviction_list);
155 	while (!list_empty(&unwind_list)) {
156 		obj = list_first_entry(&unwind_list,
157 				       struct drm_i915_gem_object,
158 				       exec_list);
159 		if (drm_mm_scan_remove_block(obj->gtt_space)) {
160 			list_move(&obj->exec_list, &eviction_list);
161 			continue;
162 		}
163 		list_del_init(&obj->exec_list);
164 		drm_gem_object_unreference(&obj->base);
165 	}
166 
167 	/* Unbinding will emit any required flushes */
168 	while (!list_empty(&eviction_list)) {
169 		obj = list_first_entry(&eviction_list,
170 				       struct drm_i915_gem_object,
171 				       exec_list);
172 		if (ret == 0)
173 			ret = i915_gem_object_unbind(obj);
174 
175 		list_del_init(&obj->exec_list);
176 		drm_gem_object_unreference(&obj->base);
177 	}
178 
179 	return ret;
180 }
181 
182 int
183 i915_gem_evict_everything(struct drm_device *dev, bool purgeable_only)
184 {
185 	drm_i915_private_t *dev_priv = dev->dev_private;
186 	int ret;
187 	bool lists_empty;
188 
189 	lists_empty = (list_empty(&dev_priv->mm.inactive_list) &&
190 		       list_empty(&dev_priv->mm.flushing_list) &&
191 		       list_empty(&dev_priv->mm.active_list));
192 	if (lists_empty)
193 		return -ENOSPC;
194 
195 	trace_i915_gem_evict_everything(dev, purgeable_only);
196 
197 	/* Flush everything (on to the inactive lists) and evict */
198 	ret = i915_gpu_idle(dev);
199 	if (ret)
200 		return ret;
201 
202 	BUG_ON(!list_empty(&dev_priv->mm.flushing_list));
203 
204 	return i915_gem_evict_inactive(dev, purgeable_only);
205 }
206 
207 /** Unbinds all inactive objects. */
208 int
209 i915_gem_evict_inactive(struct drm_device *dev, bool purgeable_only)
210 {
211 	drm_i915_private_t *dev_priv = dev->dev_private;
212 	struct drm_i915_gem_object *obj, *next;
213 
214 	list_for_each_entry_safe(obj, next,
215 				 &dev_priv->mm.inactive_list, mm_list) {
216 		if (!purgeable_only || obj->madv != I915_MADV_WILLNEED) {
217 			int ret = i915_gem_object_unbind(obj);
218 			if (ret)
219 				return ret;
220 		}
221 	}
222 
223 	return 0;
224 }
225