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