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 	if (obj->pin_count)
39 		return false;
40 
41 	list_add(&obj->exec_list, unwind);
42 	return drm_mm_scan_add_block(obj->gtt_space);
43 }
44 
45 int
46 i915_gem_evict_something(struct drm_device *dev, int min_size,
47 			 unsigned alignment, bool mappable)
48 {
49 	drm_i915_private_t *dev_priv = dev->dev_private;
50 	struct list_head eviction_list, unwind_list;
51 	struct drm_i915_gem_object *obj;
52 	int ret = 0;
53 
54 	trace_i915_gem_evict(dev, min_size, alignment, mappable);
55 
56 	/*
57 	 * The goal is to evict objects and amalgamate space in LRU order.
58 	 * The oldest idle objects reside on the inactive list, which is in
59 	 * retirement order. The next objects to retire are those on the (per
60 	 * ring) active list that do not have an outstanding flush. Once the
61 	 * hardware reports completion (the seqno is updated after the
62 	 * batchbuffer has been finished) the clean buffer objects would
63 	 * be retired to the inactive list. Any dirty objects would be added
64 	 * to the tail of the flushing list. So after processing the clean
65 	 * active objects we need to emit a MI_FLUSH to retire the flushing
66 	 * list, hence the retirement order of the flushing list is in
67 	 * advance of the dirty objects on the active lists.
68 	 *
69 	 * The retirement sequence is thus:
70 	 *   1. Inactive objects (already retired)
71 	 *   2. Clean active objects
72 	 *   3. Flushing list
73 	 *   4. Dirty active objects.
74 	 *
75 	 * On each list, the oldest objects lie at the HEAD with the freshest
76 	 * object on the TAIL.
77 	 */
78 
79 	INIT_LIST_HEAD(&unwind_list);
80 	if (mappable)
81 		drm_mm_init_scan_with_range(&dev_priv->mm.gtt_space, min_size,
82 					    alignment, 0,
83 					    dev_priv->mm.gtt_mappable_end);
84 	else
85 		drm_mm_init_scan(&dev_priv->mm.gtt_space, min_size, alignment);
86 
87 	/* First see if there is a large enough contiguous idle region... */
88 	list_for_each_entry(obj, &dev_priv->mm.inactive_list, mm_list) {
89 		if (mark_free(obj, &unwind_list))
90 			goto found;
91 	}
92 
93 	/* Now merge in the soon-to-be-expired objects... */
94 	list_for_each_entry(obj, &dev_priv->mm.active_list, mm_list) {
95 		/* Does the object require an outstanding flush? */
96 		if (obj->base.write_domain)
97 			continue;
98 
99 		if (mark_free(obj, &unwind_list))
100 			goto found;
101 	}
102 
103 	/* Finally add anything with a pending flush (in order of retirement) */
104 	list_for_each_entry(obj, &dev_priv->mm.flushing_list, mm_list) {
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)
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 	struct drm_i915_gem_object *obj, *next;
170 	bool lists_empty;
171 	int ret;
172 
173 	lists_empty = (list_empty(&dev_priv->mm.inactive_list) &&
174 		       list_empty(&dev_priv->mm.flushing_list) &&
175 		       list_empty(&dev_priv->mm.active_list));
176 	if (lists_empty)
177 		return -ENOSPC;
178 
179 	trace_i915_gem_evict_everything(dev, purgeable_only);
180 
181 	/* The gpu_idle will flush everything in the write domain to the
182 	 * active list. Then we must move everything off the active list
183 	 * with retire requests.
184 	 */
185 	ret = i915_gpu_idle(dev);
186 	if (ret)
187 		return ret;
188 
189 	i915_gem_retire_requests(dev);
190 
191 	BUG_ON(!list_empty(&dev_priv->mm.flushing_list));
192 
193 	/* Having flushed everything, unbind() should never raise an error */
194 	list_for_each_entry_safe(obj, next,
195 				 &dev_priv->mm.inactive_list, mm_list) {
196 		if (!purgeable_only || obj->madv != I915_MADV_WILLNEED) {
197 			if (obj->pin_count == 0)
198 				WARN_ON(i915_gem_object_unbind(obj));
199 		}
200 	}
201 
202 	return 0;
203 }
204