xref: /linux/drivers/gpu/drm/i915/i915_gem_evict.c (revision c4ee0af3fa0dc65f690fc908f02b8355f9576ea0)
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 	if (WARN_ON(!list_empty(&vma->exec_list)))
41 		return false;
42 
43 	list_add(&vma->exec_list, unwind);
44 	return drm_mm_scan_add_block(&vma->node);
45 }
46 
47 int
48 i915_gem_evict_something(struct drm_device *dev, struct i915_address_space *vm,
49 			 int min_size, unsigned alignment, unsigned cache_level,
50 			 bool mappable, bool nonblocking)
51 {
52 	drm_i915_private_t *dev_priv = dev->dev_private;
53 	struct list_head eviction_list, unwind_list;
54 	struct i915_vma *vma;
55 	int ret = 0;
56 
57 	trace_i915_gem_evict(dev, min_size, alignment, mappable);
58 
59 	/*
60 	 * The goal is to evict objects and amalgamate space in LRU order.
61 	 * The oldest idle objects reside on the inactive list, which is in
62 	 * retirement order. The next objects to retire are those on the (per
63 	 * ring) active list that do not have an outstanding flush. Once the
64 	 * hardware reports completion (the seqno is updated after the
65 	 * batchbuffer has been finished) the clean buffer objects would
66 	 * be retired to the inactive list. Any dirty objects would be added
67 	 * to the tail of the flushing list. So after processing the clean
68 	 * active objects we need to emit a MI_FLUSH to retire the flushing
69 	 * list, hence the retirement order of the flushing list is in
70 	 * advance of the dirty objects on the active lists.
71 	 *
72 	 * The retirement sequence is thus:
73 	 *   1. Inactive objects (already retired)
74 	 *   2. Clean active objects
75 	 *   3. Flushing list
76 	 *   4. Dirty active objects.
77 	 *
78 	 * On each list, the oldest objects lie at the HEAD with the freshest
79 	 * object on the TAIL.
80 	 */
81 
82 	INIT_LIST_HEAD(&unwind_list);
83 	if (mappable) {
84 		BUG_ON(!i915_is_ggtt(vm));
85 		drm_mm_init_scan_with_range(&vm->mm, min_size,
86 					    alignment, cache_level, 0,
87 					    dev_priv->gtt.mappable_end);
88 	} else
89 		drm_mm_init_scan(&vm->mm, min_size, alignment, cache_level);
90 
91 search_again:
92 	/* First see if there is a large enough contiguous idle region... */
93 	list_for_each_entry(vma, &vm->inactive_list, mm_list) {
94 		if (mark_free(vma, &unwind_list))
95 			goto found;
96 	}
97 
98 	if (nonblocking)
99 		goto none;
100 
101 	/* Now merge in the soon-to-be-expired objects... */
102 	list_for_each_entry(vma, &vm->active_list, mm_list) {
103 		if (mark_free(vma, &unwind_list))
104 			goto found;
105 	}
106 
107 none:
108 	/* Nothing found, clean up and bail out! */
109 	while (!list_empty(&unwind_list)) {
110 		vma = list_first_entry(&unwind_list,
111 				       struct i915_vma,
112 				       exec_list);
113 		ret = drm_mm_scan_remove_block(&vma->node);
114 		BUG_ON(ret);
115 
116 		list_del_init(&vma->exec_list);
117 	}
118 
119 	/* Can we unpin some objects such as idle hw contents,
120 	 * or pending flips?
121 	 */
122 	ret = nonblocking ? -ENOSPC : i915_gpu_idle(dev);
123 	if (ret)
124 		return ret;
125 
126 	/* Only idle the GPU and repeat the search once */
127 	i915_gem_retire_requests(dev);
128 	nonblocking = true;
129 	goto search_again;
130 
131 found:
132 	/* drm_mm doesn't allow any other other operations while
133 	 * scanning, therefore store to be evicted objects on a
134 	 * temporary list. */
135 	INIT_LIST_HEAD(&eviction_list);
136 	while (!list_empty(&unwind_list)) {
137 		vma = list_first_entry(&unwind_list,
138 				       struct i915_vma,
139 				       exec_list);
140 		if (drm_mm_scan_remove_block(&vma->node)) {
141 			list_move(&vma->exec_list, &eviction_list);
142 			drm_gem_object_reference(&vma->obj->base);
143 			continue;
144 		}
145 		list_del_init(&vma->exec_list);
146 	}
147 
148 	/* Unbinding will emit any required flushes */
149 	while (!list_empty(&eviction_list)) {
150 		struct drm_gem_object *obj;
151 		vma = list_first_entry(&eviction_list,
152 				       struct i915_vma,
153 				       exec_list);
154 
155 		obj =  &vma->obj->base;
156 		list_del_init(&vma->exec_list);
157 		if (ret == 0)
158 			ret = i915_vma_unbind(vma);
159 
160 		drm_gem_object_unreference(obj);
161 	}
162 
163 	return ret;
164 }
165 
166 /**
167  * i915_gem_evict_vm - Try to free up VM space
168  *
169  * @vm: Address space to evict from
170  * @do_idle: Boolean directing whether to idle first.
171  *
172  * VM eviction is about freeing up virtual address space. If one wants fine
173  * grained eviction, they should see evict something for more details. In terms
174  * of freeing up actual system memory, this function may not accomplish the
175  * desired result. An object may be shared in multiple address space, and this
176  * function will not assert those objects be freed.
177  *
178  * Using do_idle will result in a more complete eviction because it retires, and
179  * inactivates current BOs.
180  */
181 int i915_gem_evict_vm(struct i915_address_space *vm, bool do_idle)
182 {
183 	struct i915_vma *vma, *next;
184 	int ret;
185 
186 	trace_i915_gem_evict_vm(vm);
187 
188 	if (do_idle) {
189 		ret = i915_gpu_idle(vm->dev);
190 		if (ret)
191 			return ret;
192 
193 		i915_gem_retire_requests(vm->dev);
194 	}
195 
196 	list_for_each_entry_safe(vma, next, &vm->inactive_list, mm_list)
197 		if (vma->obj->pin_count == 0)
198 			WARN_ON(i915_vma_unbind(vma));
199 
200 	return 0;
201 }
202 
203 int
204 i915_gem_evict_everything(struct drm_device *dev)
205 {
206 	drm_i915_private_t *dev_priv = dev->dev_private;
207 	struct i915_address_space *vm;
208 	bool lists_empty = true;
209 	int ret;
210 
211 	list_for_each_entry(vm, &dev_priv->vm_list, global_link) {
212 		lists_empty = (list_empty(&vm->inactive_list) &&
213 			       list_empty(&vm->active_list));
214 		if (!lists_empty)
215 			lists_empty = false;
216 	}
217 
218 	if (lists_empty)
219 		return -ENOSPC;
220 
221 	trace_i915_gem_evict_everything(dev);
222 
223 	/* The gpu_idle will flush everything in the write domain to the
224 	 * active list. Then we must move everything off the active list
225 	 * with retire requests.
226 	 */
227 	ret = i915_gpu_idle(dev);
228 	if (ret)
229 		return ret;
230 
231 	i915_gem_retire_requests(dev);
232 
233 	/* Having flushed everything, unbind() should never raise an error */
234 	list_for_each_entry(vm, &dev_priv->vm_list, global_link)
235 		WARN_ON(i915_gem_evict_vm(vm, false));
236 
237 	return 0;
238 }
239