i915_gem_evict.c revision 277487 
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 <sys/cdefs.h>
30__FBSDID("$FreeBSD: head/sys/dev/drm2/i915/i915_gem_evict.c 277487 2015-01-21 16:10:37Z kib $");
31
32#include <dev/drm2/drmP.h>
33#include <dev/drm2/drm.h>
34#include <dev/drm2/i915/i915_drm.h>
35#include <dev/drm2/i915/i915_drv.h>
36
37static bool
38mark_free(struct drm_i915_gem_object *obj, struct list_head *unwind)
39{
40	if (obj->pin_count)
41		return false;
42
43	list_add(&obj->exec_list, unwind);
44	return drm_mm_scan_add_block(obj->gtt_space);
45}
46
47int
48i915_gem_evict_something(struct drm_device *dev, int min_size,
49			 unsigned alignment, bool mappable)
50{
51	drm_i915_private_t *dev_priv = dev->dev_private;
52	struct list_head eviction_list, unwind_list;
53	struct drm_i915_gem_object *obj;
54	int ret = 0;
55
56	CTR4(KTR_DRM, "evict_something %p %d %u %d", dev, min_size,
57	    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		drm_mm_init_scan_with_range(&dev_priv->mm.gtt_space, min_size,
85					    alignment, 0,
86					    dev_priv->mm.gtt_mappable_end);
87	else
88		drm_mm_init_scan(&dev_priv->mm.gtt_space, min_size, alignment);
89
90	/* First see if there is a large enough contiguous idle region... */
91	list_for_each_entry(obj, &dev_priv->mm.inactive_list, mm_list) {
92		if (mark_free(obj, &unwind_list))
93			goto found;
94	}
95
96	/* Now merge in the soon-to-be-expired objects... */
97	list_for_each_entry(obj, &dev_priv->mm.active_list, mm_list) {
98		/* Does the object require an outstanding flush? */
99		if (obj->base.write_domain)
100			continue;
101
102		if (mark_free(obj, &unwind_list))
103			goto found;
104	}
105
106	/* Finally add anything with a pending flush (in order of retirement) */
107	list_for_each_entry(obj, &dev_priv->mm.flushing_list, mm_list) {
108		if (mark_free(obj, &unwind_list))
109			goto found;
110	}
111	list_for_each_entry(obj, &dev_priv->mm.active_list, mm_list) {
112		if (!obj->base.write_domain)
113			continue;
114
115		if (mark_free(obj, &unwind_list))
116			goto found;
117	}
118
119	/* Nothing found, clean up and bail out! */
120	while (!list_empty(&unwind_list)) {
121		obj = list_first_entry(&unwind_list,
122				       struct drm_i915_gem_object,
123				       exec_list);
124
125		ret = drm_mm_scan_remove_block(obj->gtt_space);
126		KASSERT(ret == 0, ("drm_mm_scan_remove_block failed %d", ret));
127
128		list_del_init(&obj->exec_list);
129	}
130
131	/* We expect the caller to unpin, evict all and try again, or give up.
132	 * So calling i915_gem_evict_everything() is unnecessary.
133	 */
134	return -ENOSPC;
135
136found:
137	/* drm_mm doesn't allow any other other operations while
138	 * scanning, therefore store to be evicted objects on a
139	 * temporary list. */
140	INIT_LIST_HEAD(&eviction_list);
141	while (!list_empty(&unwind_list)) {
142		obj = list_first_entry(&unwind_list,
143				       struct drm_i915_gem_object,
144				       exec_list);
145		if (drm_mm_scan_remove_block(obj->gtt_space)) {
146			list_move(&obj->exec_list, &eviction_list);
147			drm_gem_object_reference(&obj->base);
148			continue;
149		}
150		list_del_init(&obj->exec_list);
151	}
152
153	/* Unbinding will emit any required flushes */
154	while (!list_empty(&eviction_list)) {
155		obj = list_first_entry(&eviction_list,
156				       struct drm_i915_gem_object,
157				       exec_list);
158		if (ret == 0)
159			ret = i915_gem_object_unbind(obj);
160
161		list_del_init(&obj->exec_list);
162		drm_gem_object_unreference(&obj->base);
163	}
164
165	return ret;
166}
167
168int
169i915_gem_evict_everything(struct drm_device *dev, bool purgeable_only)
170{
171	drm_i915_private_t *dev_priv = dev->dev_private;
172	struct drm_i915_gem_object *obj, *next;
173	bool lists_empty;
174	int ret;
175
176	lists_empty = (list_empty(&dev_priv->mm.inactive_list) &&
177		       list_empty(&dev_priv->mm.flushing_list) &&
178		       list_empty(&dev_priv->mm.active_list));
179	if (lists_empty)
180		return -ENOSPC;
181
182	CTR2(KTR_DRM, "evict_everything %p %d", dev, purgeable_only);
183
184	/* The gpu_idle will flush everything in the write domain to the
185	 * active list. Then we must move everything off the active list
186	 * with retire requests.
187	 */
188	ret = i915_gpu_idle(dev);
189	if (ret)
190		return ret;
191
192	i915_gem_retire_requests(dev);
193
194	KASSERT(list_empty(&dev_priv->mm.flushing_list),
195	    ("flush list not empty"));
196
197	/* Having flushed everything, unbind() should never raise an error */
198	list_for_each_entry_safe(obj, next,
199				 &dev_priv->mm.inactive_list, mm_list) {
200		if (!purgeable_only || obj->madv != I915_MADV_WILLNEED) {
201			if (obj->pin_count == 0)
202				i915_gem_object_unbind(obj);
203		}
204	}
205
206	return 0;
207}
208