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 <drm/drmP.h>
30 #include "i915_drv.h"
31 #include <drm/i915_drm.h>
32 #include "i915_trace.h"
33 
34 static bool
35 mark_free(struct i915_vma *vma, struct list_head *unwind)
36 {
37 	if (vma->obj->pin_count)
38 		return false;
39 
40 	list_add(&vma->exec_list, unwind);
41 	return drm_mm_scan_add_block(&vma->node);
42 }
43 
44 int
45 i915_gem_evict_something(struct drm_device *dev, struct i915_address_space *vm,
46 			 int min_size, unsigned alignment, unsigned cache_level,
47 			 bool mappable, bool nonblocking)
48 {
49 	drm_i915_private_t *dev_priv = dev->dev_private;
50 	struct list_head eviction_list, unwind_list;
51 	struct i915_vma *vma;
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 		BUG_ON(!i915_is_ggtt(vm));
82 		drm_mm_init_scan_with_range(&vm->mm, min_size,
83 					    alignment, cache_level, 0,
84 					    dev_priv->gtt.mappable_end);
85 	} else
86 		drm_mm_init_scan(&vm->mm, min_size, alignment, cache_level);
87 
88 	/* First see if there is a large enough contiguous idle region... */
89 	list_for_each_entry(vma, &vm->inactive_list, mm_list) {
90 		if (mark_free(vma, &unwind_list))
91 			goto found;
92 	}
93 
94 	if (nonblocking)
95 		goto none;
96 
97 	/* Now merge in the soon-to-be-expired objects... */
98 	list_for_each_entry(vma, &vm->active_list, mm_list) {
99 		if (mark_free(vma, &unwind_list))
100 			goto found;
101 	}
102 
103 none:
104 	/* Nothing found, clean up and bail out! */
105 	while (!list_empty(&unwind_list)) {
106 		vma = list_first_entry(&unwind_list,
107 				       struct i915_vma,
108 				       exec_list);
109 		ret = drm_mm_scan_remove_block(&vma->node);
110 		BUG_ON(ret);
111 
112 		list_del_init(&vma->exec_list);
113 	}
114 
115 	/* We expect the caller to unpin, evict all and try again, or give up.
116 	 * So calling i915_gem_evict_everything() is unnecessary.
117 	 */
118 	return -ENOSPC;
119 
120 found:
121 	/* drm_mm doesn't allow any other other operations while
122 	 * scanning, therefore store to be evicted objects on a
123 	 * temporary list. */
124 	INIT_LIST_HEAD(&eviction_list);
125 	while (!list_empty(&unwind_list)) {
126 		vma = list_first_entry(&unwind_list,
127 				       struct i915_vma,
128 				       exec_list);
129 		if (drm_mm_scan_remove_block(&vma->node)) {
130 			list_move(&vma->exec_list, &eviction_list);
131 			drm_gem_object_reference(&vma->obj->base);
132 			continue;
133 		}
134 		list_del_init(&vma->exec_list);
135 	}
136 
137 	/* Unbinding will emit any required flushes */
138 	while (!list_empty(&eviction_list)) {
139 		struct drm_gem_object *obj;
140 		vma = list_first_entry(&eviction_list,
141 				       struct i915_vma,
142 				       exec_list);
143 
144 		obj =  &vma->obj->base;
145 		list_del_init(&vma->exec_list);
146 		if (ret == 0)
147 			ret = i915_vma_unbind(vma);
148 
149 		drm_gem_object_unreference(obj);
150 	}
151 
152 	return ret;
153 }
154 
155 int
156 i915_gem_evict_everything(struct drm_device *dev)
157 {
158 	drm_i915_private_t *dev_priv = dev->dev_private;
159 	struct i915_address_space *vm;
160 	struct i915_vma *vma, *next;
161 	bool lists_empty = true;
162 	int ret;
163 
164 	list_for_each_entry(vm, &dev_priv->vm_list, global_link) {
165 		lists_empty = (list_empty(&vm->inactive_list) &&
166 			       list_empty(&vm->active_list));
167 		if (!lists_empty)
168 			lists_empty = false;
169 	}
170 
171 	if (lists_empty)
172 		return -ENOSPC;
173 
174 	trace_i915_gem_evict_everything(dev);
175 
176 	/* The gpu_idle will flush everything in the write domain to the
177 	 * active list. Then we must move everything off the active list
178 	 * with retire requests.
179 	 */
180 	ret = i915_gpu_idle(dev);
181 	if (ret)
182 		return ret;
183 
184 	i915_gem_retire_requests(dev);
185 
186 	/* Having flushed everything, unbind() should never raise an error */
187 	list_for_each_entry(vm, &dev_priv->vm_list, global_link) {
188 		list_for_each_entry_safe(vma, next, &vm->inactive_list, mm_list)
189 			if (vma->obj->pin_count == 0)
190 				WARN_ON(i915_vma_unbind(vma));
191 	}
192 
193 	return 0;
194 }
195