summaryrefslogtreecommitdiffstats
path: root/drivers/gpu/drm/i915/i915_gem_evict.c
blob: 85ceff1b74b648cbf7438f2a53ed3168bcf12d2e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
/*
 * Copyright © 2008-2010 Intel Corporation
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the next
 * paragraph) shall be included in all copies or substantial portions of the
 * Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
 * IN THE SOFTWARE.
 *
 * Authors:
 *    Eric Anholt <eric@anholt.net>
 *    Chris Wilson <chris@chris-wilson.co.uuk>
 *
 */

#include <drm/drmP.h>
#include <drm/i915_drm.h>

#include "i915_drv.h"
#include "intel_drv.h"
#include "i915_trace.h"

static bool ggtt_is_idle(struct drm_i915_private *dev_priv)
{
	struct i915_ggtt *ggtt = &dev_priv->ggtt;
	struct intel_engine_cs *engine;
	enum intel_engine_id id;

	for_each_engine(engine, dev_priv, id) {
		struct intel_timeline *tl;

		tl = &ggtt->base.timeline.engine[engine->id];
		if (i915_gem_active_isset(&tl->last_request))
			return false;
	}

	return true;
}

static bool
mark_free(struct drm_mm_scan *scan,
	  struct i915_vma *vma,
	  unsigned int flags,
	  struct list_head *unwind)
{
	if (i915_vma_is_pinned(vma))
		return false;

	if (WARN_ON(!list_empty(&vma->exec_list)))
		return false;

	if (flags & PIN_NONFAULT && !list_empty(&vma->obj->userfault_link))
		return false;

	list_add(&vma->exec_list, unwind);
	return drm_mm_scan_add_block(scan, &vma->node);
}

/**
 * i915_gem_evict_something - Evict vmas to make room for binding a new one
 * @vm: address space to evict from
 * @min_size: size of the desired free space
 * @alignment: alignment constraint of the desired free space
 * @cache_level: cache_level for the desired space
 * @start: start (inclusive) of the range from which to evict objects
 * @end: end (exclusive) of the range from which to evict objects
 * @flags: additional flags to control the eviction algorithm
 *
 * This function will try to evict vmas until a free space satisfying the
 * requirements is found. Callers must check first whether any such hole exists
 * already before calling this function.
 *
 * This function is used by the object/vma binding code.
 *
 * Since this function is only used to free up virtual address space it only
 * ignores pinned vmas, and not object where the backing storage itself is
 * pinned. Hence obj->pages_pin_count does not protect against eviction.
 *
 * To clarify: This is for freeing up virtual address space, not for freeing
 * memory in e.g. the shrinker.
 */
int
i915_gem_evict_something(struct i915_address_space *vm,
			 u64 min_size, u64 alignment,
			 unsigned cache_level,
			 u64 start, u64 end,
			 unsigned flags)
{
	struct drm_i915_private *dev_priv = to_i915(vm->dev);
	struct drm_mm_scan scan;
	struct list_head eviction_list;
	struct list_head *phases[] = {
		&vm->inactive_list,
		&vm->active_list,
		NULL,
	}, **phase;
	struct i915_vma *vma, *next;
	struct drm_mm_node *node;
	int ret;

	lockdep_assert_held(&vm->dev->struct_mutex);
	trace_i915_gem_evict(vm, min_size, alignment, flags);

	/*
	 * The goal is to evict objects and amalgamate space in LRU order.
	 * The oldest idle objects reside on the inactive list, which is in
	 * retirement order. The next objects to retire are those in flight,
	 * on the active list, again in retirement order.
	 *
	 * The retirement sequence is thus:
	 *   1. Inactive objects (already retired)
	 *   2. Active objects (will stall on unbinding)
	 *
	 * On each list, the oldest objects lie at the HEAD with the freshest
	 * object on the TAIL.
	 */
	drm_mm_scan_init_with_range(&scan, &vm->mm,
				    min_size, alignment, cache_level,
				    start, end,
				    flags & PIN_HIGH ? DRM_MM_CREATE_TOP : 0);

	if (flags & PIN_NONBLOCK)
		phases[1] = NULL;

search_again:
	INIT_LIST_HEAD(&eviction_list);
	phase = phases;
	do {
		list_for_each_entry(vma, *phase, vm_link)
			if (mark_free(&scan, vma, flags, &eviction_list))
				goto found;
	} while (*++phase);

	/* Nothing found, clean up and bail out! */
	list_for_each_entry_safe(vma, next, &eviction_list, exec_list) {
		ret = drm_mm_scan_remove_block(&scan, &vma->node);
		BUG_ON(ret);

		INIT_LIST_HEAD(&vma->exec_list);
	}

	/* Can we unpin some objects such as idle hw contents,
	 * or pending flips? But since only the GGTT has global entries
	 * such as scanouts, rinbuffers and contexts, we can skip the
	 * purge when inspecting per-process local address spaces.
	 */
	if (!i915_is_ggtt(vm) || flags & PIN_NONBLOCK)
		return -ENOSPC;

	if (ggtt_is_idle(dev_priv)) {
		/* If we still have pending pageflip completions, drop
		 * back to userspace to give our workqueues time to
		 * acquire our locks and unpin the old scanouts.
		 */
		return intel_has_pending_fb_unpin(vm->dev) ? -EAGAIN : -ENOSPC;
	}

	/* Not everything in the GGTT is tracked via vma (otherwise we
	 * could evict as required with minimal stalling) so we are forced
	 * to idle the GPU and explicitly retire outstanding requests in
	 * the hopes that we can then remove contexts and the like only
	 * bound by their active reference.
	 */
	ret = i915_gem_switch_to_kernel_context(dev_priv);
	if (ret)
		return ret;

	ret = i915_gem_wait_for_idle(dev_priv,
				     I915_WAIT_INTERRUPTIBLE |
				     I915_WAIT_LOCKED);
	if (ret)
		return ret;

	i915_gem_retire_requests(dev_priv);
	goto search_again;

found:
	/* drm_mm doesn't allow any other other operations while
	 * scanning, therefore store to-be-evicted objects on a
	 * temporary list and take a reference for all before
	 * calling unbind (which may remove the active reference
	 * of any of our objects, thus corrupting the list).
	 */
	list_for_each_entry_safe(vma, next, &eviction_list, exec_list) {
		if (drm_mm_scan_remove_block(&scan, &vma->node))
			__i915_vma_pin(vma);
		else
			list_del_init(&vma->exec_list);
	}

	/* Unbinding will emit any required flushes */
	while (!list_empty(&eviction_list)) {
		vma = list_first_entry(&eviction_list,
				       struct i915_vma,
				       exec_list);

		list_del_init(&vma->exec_list);
		__i915_vma_unpin(vma);
		if (ret == 0)
			ret = i915_vma_unbind(vma);
	}

	while (ret == 0 && (node = drm_mm_scan_color_evict(&scan))) {
		vma = container_of(node, struct i915_vma, node);
		ret = i915_vma_unbind(vma);
	}

	return ret;
}

int
i915_gem_evict_for_vma(struct i915_vma *target)
{
	struct drm_mm_node *node, *next;

	lockdep_assert_held(&target->vm->dev->struct_mutex);

	list_for_each_entry_safe(node, next,
			&target->vm->mm.head_node.node_list,
			node_list) {
		struct i915_vma *vma;
		int ret;

		if (node->start + node->size <= target->node.start)
			continue;
		if (node->start >= target->node.start + target->node.size)
			break;

		vma = container_of(node, typeof(*vma), node);

		if (i915_vma_is_pinned(vma)) {
			if (!vma->exec_entry || i915_vma_pin_count(vma) > 1)
				/* Object is pinned for some other use */
				return -EBUSY;

			/* We need to evict a buffer in the same batch */
			if (vma->exec_entry->flags & EXEC_OBJECT_PINNED)
				/* Overlapping fixed objects in the same batch */
				return -EINVAL;

			return -ENOSPC;
		}

		ret = i915_vma_unbind(vma);
		if (ret)
			return ret;
	}

	return 0;
}

/**
 * i915_gem_evict_vm - Evict all idle vmas from a vm
 * @vm: Address space to cleanse
 * @do_idle: Boolean directing whether to idle first.
 *
 * This function evicts all idles vmas from a vm. If all unpinned vmas should be
 * evicted the @do_idle needs to be set to true.
 *
 * This is used by the execbuf code as a last-ditch effort to defragment the
 * address space.
 *
 * To clarify: This is for freeing up virtual address space, not for freeing
 * memory in e.g. the shrinker.
 */
int i915_gem_evict_vm(struct i915_address_space *vm, bool do_idle)
{
	struct i915_vma *vma, *next;
	int ret;

	lockdep_assert_held(&vm->dev->struct_mutex);
	trace_i915_gem_evict_vm(vm);

	if (do_idle) {
		struct drm_i915_private *dev_priv = to_i915(vm->dev);

		if (i915_is_ggtt(vm)) {
			ret = i915_gem_switch_to_kernel_context(dev_priv);
			if (ret)
				return ret;
		}

		ret = i915_gem_wait_for_idle(dev_priv,
					     I915_WAIT_INTERRUPTIBLE |
					     I915_WAIT_LOCKED);
		if (ret)
			return ret;

		i915_gem_retire_requests(dev_priv);
		WARN_ON(!list_empty(&vm->active_list));
	}

	list_for_each_entry_safe(vma, next, &vm->inactive_list, vm_link)
		if (!i915_vma_is_pinned(vma))
			WARN_ON(i915_vma_unbind(vma));

	return 0;
}
OpenPOWER on IntegriCloud