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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 <drm/i915_drm.h>
31
32#include "i915_drv.h"
33#include "intel_drv.h"
34#include "i915_trace.h"
35
36static bool
37mark_free(struct i915_vma *vma, struct list_head *unwind)
38{
39 if (vma->pin_count)
40 return false;
41
42 if (WARN_ON(!list_empty(&vma->exec_list)))
43 return false;
44
45 list_add(&vma->exec_list, unwind);
46 return drm_mm_scan_add_block(&vma->node);
47}
48
49/**
50 * i915_gem_evict_something - Evict vmas to make room for binding a new one
51 * @dev: drm_device
52 * @vm: address space to evict from
53 * @min_size: size of the desired free space
54 * @alignment: alignment constraint of the desired free space
55 * @cache_level: cache_level for the desired space
56 * @start: start (inclusive) of the range from which to evict objects
57 * @end: end (exclusive) of the range from which to evict objects
58 * @flags: additional flags to control the eviction algorithm
59 *
60 * This function will try to evict vmas until a free space satisfying the
61 * requirements is found. Callers must check first whether any such hole exists
62 * already before calling this function.
63 *
64 * This function is used by the object/vma binding code.
65 *
66 * Since this function is only used to free up virtual address space it only
67 * ignores pinned vmas, and not object where the backing storage itself is
68 * pinned. Hence obj->pages_pin_count does not protect against eviction.
69 *
70 * To clarify: This is for freeing up virtual address space, not for freeing
71 * memory in e.g. the shrinker.
72 */
73int
74i915_gem_evict_something(struct drm_device *dev, struct i915_address_space *vm,
75 int min_size, unsigned alignment, unsigned cache_level,
76 unsigned long start, unsigned long end,
77 unsigned flags)
78{
79 struct list_head eviction_list, unwind_list;
80 struct i915_vma *vma;
81 int ret = 0;
82 int pass = 0;
83
84 trace_i915_gem_evict(dev, min_size, alignment, flags);
85
86 /*
87 * The goal is to evict objects and amalgamate space in LRU order.
88 * The oldest idle objects reside on the inactive list, which is in
89 * retirement order. The next objects to retire are those on the (per
90 * ring) active list that do not have an outstanding flush. Once the
91 * hardware reports completion (the seqno is updated after the
92 * batchbuffer has been finished) the clean buffer objects would
93 * be retired to the inactive list. Any dirty objects would be added
94 * to the tail of the flushing list. So after processing the clean
95 * active objects we need to emit a MI_FLUSH to retire the flushing
96 * list, hence the retirement order of the flushing list is in
97 * advance of the dirty objects on the active lists.
98 *
99 * The retirement sequence is thus:
100 * 1. Inactive objects (already retired)
101 * 2. Clean active objects
102 * 3. Flushing list
103 * 4. Dirty active objects.
104 *
105 * On each list, the oldest objects lie at the HEAD with the freshest
106 * object on the TAIL.
107 */
108
109 INIT_LIST_HEAD(&unwind_list);
110 if (start != 0 || end != vm->total) {
111 drm_mm_init_scan_with_range(&vm->mm, min_size,
112 alignment, cache_level,
113 start, end);
114 } else
115 drm_mm_init_scan(&vm->mm, min_size, alignment, cache_level);
116
117search_again:
118 /* First see if there is a large enough contiguous idle region... */
119 list_for_each_entry(vma, &vm->inactive_list, vm_link) {
120 if (mark_free(vma, &unwind_list))
121 goto found;
122 }
123
124 if (flags & PIN_NONBLOCK)
125 goto none;
126
127 /* Now merge in the soon-to-be-expired objects... */
128 list_for_each_entry(vma, &vm->active_list, vm_link) {
129 if (mark_free(vma, &unwind_list))
130 goto found;
131 }
132
133none:
134 /* Nothing found, clean up and bail out! */
135 while (!list_empty(&unwind_list)) {
136 vma = list_first_entry(&unwind_list,
137 struct i915_vma,
138 exec_list);
139 ret = drm_mm_scan_remove_block(&vma->node);
140 BUG_ON(ret);
141
142 list_del_init(&vma->exec_list);
143 }
144
145 /* Can we unpin some objects such as idle hw contents,
146 * or pending flips?
147 */
148 if (flags & PIN_NONBLOCK)
149 return -ENOSPC;
150
151 /* Only idle the GPU and repeat the search once */
152 if (pass++ == 0) {
153 ret = i915_gpu_idle(dev);
154 if (ret)
155 return ret;
156
157 i915_gem_retire_requests(dev);
158 goto search_again;
159 }
160
161 /* If we still have pending pageflip completions, drop
162 * back to userspace to give our workqueues time to
163 * acquire our locks and unpin the old scanouts.
164 */
165 return intel_has_pending_fb_unpin(dev) ? -EAGAIN : -ENOSPC;
166
167found:
168 /* drm_mm doesn't allow any other other operations while
169 * scanning, therefore store to be evicted objects on a
170 * temporary list. */
171 INIT_LIST_HEAD(&eviction_list);
172 while (!list_empty(&unwind_list)) {
173 vma = list_first_entry(&unwind_list,
174 struct i915_vma,
175 exec_list);
176 if (drm_mm_scan_remove_block(&vma->node)) {
177 list_move(&vma->exec_list, &eviction_list);
178 drm_gem_object_reference(&vma->obj->base);
179 continue;
180 }
181 list_del_init(&vma->exec_list);
182 }
183
184 /* Unbinding will emit any required flushes */
185 while (!list_empty(&eviction_list)) {
186 struct drm_gem_object *obj;
187 vma = list_first_entry(&eviction_list,
188 struct i915_vma,
189 exec_list);
190
191 obj = &vma->obj->base;
192 list_del_init(&vma->exec_list);
193 if (ret == 0)
194 ret = i915_vma_unbind(vma);
195
196 drm_gem_object_unreference(obj);
197 }
198
199 return ret;
200}
201
202int
203i915_gem_evict_for_vma(struct i915_vma *target)
204{
205 struct drm_mm_node *node, *next;
206
207 list_for_each_entry_safe(node, next,
208 &target->vm->mm.head_node.node_list,
209 node_list) {
210 struct i915_vma *vma;
211 int ret;
212
213 if (node->start + node->size <= target->node.start)
214 continue;
215 if (node->start >= target->node.start + target->node.size)
216 break;
217
218 vma = container_of(node, typeof(*vma), node);
219
220 if (vma->pin_count) {
221 if (!vma->exec_entry || (vma->pin_count > 1))
222 /* Object is pinned for some other use */
223 return -EBUSY;
224
225 /* We need to evict a buffer in the same batch */
226 if (vma->exec_entry->flags & EXEC_OBJECT_PINNED)
227 /* Overlapping fixed objects in the same batch */
228 return -EINVAL;
229
230 return -ENOSPC;
231 }
232
233 ret = i915_vma_unbind(vma);
234 if (ret)
235 return ret;
236 }
237
238 return 0;
239}
240
241/**
242 * i915_gem_evict_vm - Evict all idle vmas from a vm
243 * @vm: Address space to cleanse
244 * @do_idle: Boolean directing whether to idle first.
245 *
246 * This function evicts all idles vmas from a vm. If all unpinned vmas should be
247 * evicted the @do_idle needs to be set to true.
248 *
249 * This is used by the execbuf code as a last-ditch effort to defragment the
250 * address space.
251 *
252 * To clarify: This is for freeing up virtual address space, not for freeing
253 * memory in e.g. the shrinker.
254 */
255int i915_gem_evict_vm(struct i915_address_space *vm, bool do_idle)
256{
257 struct i915_vma *vma, *next;
258 int ret;
259
260 WARN_ON(!mutex_is_locked(&vm->dev->struct_mutex));
261 trace_i915_gem_evict_vm(vm);
262
263 if (do_idle) {
264 ret = i915_gpu_idle(vm->dev);
265 if (ret)
266 return ret;
267
268 i915_gem_retire_requests(vm->dev);
269
270 WARN_ON(!list_empty(&vm->active_list));
271 }
272
273 list_for_each_entry_safe(vma, next, &vm->inactive_list, vm_link)
274 if (vma->pin_count == 0)
275 WARN_ON(i915_vma_unbind(vma));
276
277 return 0;
278}
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/i915_drm.h>
30
31#include "gem/i915_gem_context.h"
32
33#include "i915_drv.h"
34#include "i915_trace.h"
35
36I915_SELFTEST_DECLARE(static struct igt_evict_ctl {
37 bool fail_if_busy:1;
38} igt_evict_ctl;)
39
40static int ggtt_flush(struct drm_i915_private *i915)
41{
42 /*
43 * Not everything in the GGTT is tracked via vma (otherwise we
44 * could evict as required with minimal stalling) so we are forced
45 * to idle the GPU and explicitly retire outstanding requests in
46 * the hopes that we can then remove contexts and the like only
47 * bound by their active reference.
48 */
49 return i915_gem_wait_for_idle(i915,
50 I915_WAIT_INTERRUPTIBLE |
51 I915_WAIT_LOCKED,
52 MAX_SCHEDULE_TIMEOUT);
53}
54
55static bool
56mark_free(struct drm_mm_scan *scan,
57 struct i915_vma *vma,
58 unsigned int flags,
59 struct list_head *unwind)
60{
61 if (i915_vma_is_pinned(vma))
62 return false;
63
64 list_add(&vma->evict_link, unwind);
65 return drm_mm_scan_add_block(scan, &vma->node);
66}
67
68/**
69 * i915_gem_evict_something - Evict vmas to make room for binding a new one
70 * @vm: address space to evict from
71 * @min_size: size of the desired free space
72 * @alignment: alignment constraint of the desired free space
73 * @cache_level: cache_level for the desired space
74 * @start: start (inclusive) of the range from which to evict objects
75 * @end: end (exclusive) of the range from which to evict objects
76 * @flags: additional flags to control the eviction algorithm
77 *
78 * This function will try to evict vmas until a free space satisfying the
79 * requirements is found. Callers must check first whether any such hole exists
80 * already before calling this function.
81 *
82 * This function is used by the object/vma binding code.
83 *
84 * Since this function is only used to free up virtual address space it only
85 * ignores pinned vmas, and not object where the backing storage itself is
86 * pinned. Hence obj->pages_pin_count does not protect against eviction.
87 *
88 * To clarify: This is for freeing up virtual address space, not for freeing
89 * memory in e.g. the shrinker.
90 */
91int
92i915_gem_evict_something(struct i915_address_space *vm,
93 u64 min_size, u64 alignment,
94 unsigned cache_level,
95 u64 start, u64 end,
96 unsigned flags)
97{
98 struct drm_i915_private *dev_priv = vm->i915;
99 struct drm_mm_scan scan;
100 struct list_head eviction_list;
101 struct i915_vma *vma, *next;
102 struct drm_mm_node *node;
103 enum drm_mm_insert_mode mode;
104 struct i915_vma *active;
105 int ret;
106
107 lockdep_assert_held(&vm->i915->drm.struct_mutex);
108 trace_i915_gem_evict(vm, min_size, alignment, flags);
109
110 /*
111 * The goal is to evict objects and amalgamate space in rough LRU order.
112 * Since both active and inactive objects reside on the same list,
113 * in a mix of creation and last scanned order, as we process the list
114 * we sort it into inactive/active, which keeps the active portion
115 * in a rough MRU order.
116 *
117 * The retirement sequence is thus:
118 * 1. Inactive objects (already retired, random order)
119 * 2. Active objects (will stall on unbinding, oldest scanned first)
120 */
121 mode = DRM_MM_INSERT_BEST;
122 if (flags & PIN_HIGH)
123 mode = DRM_MM_INSERT_HIGH;
124 if (flags & PIN_MAPPABLE)
125 mode = DRM_MM_INSERT_LOW;
126 drm_mm_scan_init_with_range(&scan, &vm->mm,
127 min_size, alignment, cache_level,
128 start, end, mode);
129
130 /*
131 * Retire before we search the active list. Although we have
132 * reasonable accuracy in our retirement lists, we may have
133 * a stray pin (preventing eviction) that can only be resolved by
134 * retiring.
135 */
136 if (!(flags & PIN_NONBLOCK))
137 i915_retire_requests(dev_priv);
138
139search_again:
140 active = NULL;
141 INIT_LIST_HEAD(&eviction_list);
142 list_for_each_entry_safe(vma, next, &vm->bound_list, vm_link) {
143 /*
144 * We keep this list in a rough least-recently scanned order
145 * of active elements (inactive elements are cheap to reap).
146 * New entries are added to the end, and we move anything we
147 * scan to the end. The assumption is that the working set
148 * of applications is either steady state (and thanks to the
149 * userspace bo cache it almost always is) or volatile and
150 * frequently replaced after a frame, which are self-evicting!
151 * Given that assumption, the MRU order of the scan list is
152 * fairly static, and keeping it in least-recently scan order
153 * is suitable.
154 *
155 * To notice when we complete one full cycle, we record the
156 * first active element seen, before moving it to the tail.
157 */
158 if (i915_vma_is_active(vma)) {
159 if (vma == active) {
160 if (flags & PIN_NONBLOCK)
161 break;
162
163 active = ERR_PTR(-EAGAIN);
164 }
165
166 if (active != ERR_PTR(-EAGAIN)) {
167 if (!active)
168 active = vma;
169
170 list_move_tail(&vma->vm_link, &vm->bound_list);
171 continue;
172 }
173 }
174
175 if (mark_free(&scan, vma, flags, &eviction_list))
176 goto found;
177 }
178
179 /* Nothing found, clean up and bail out! */
180 list_for_each_entry_safe(vma, next, &eviction_list, evict_link) {
181 ret = drm_mm_scan_remove_block(&scan, &vma->node);
182 BUG_ON(ret);
183 }
184
185 /*
186 * Can we unpin some objects such as idle hw contents,
187 * or pending flips? But since only the GGTT has global entries
188 * such as scanouts, rinbuffers and contexts, we can skip the
189 * purge when inspecting per-process local address spaces.
190 */
191 if (!i915_is_ggtt(vm) || flags & PIN_NONBLOCK)
192 return -ENOSPC;
193
194 /*
195 * Not everything in the GGTT is tracked via VMA using
196 * i915_vma_move_to_active(), otherwise we could evict as required
197 * with minimal stalling. Instead we are forced to idle the GPU and
198 * explicitly retire outstanding requests which will then remove
199 * the pinning for active objects such as contexts and ring,
200 * enabling us to evict them on the next iteration.
201 *
202 * To ensure that all user contexts are evictable, we perform
203 * a switch to the perma-pinned kernel context. This all also gives
204 * us a termination condition, when the last retired context is
205 * the kernel's there is no more we can evict.
206 */
207 if (I915_SELFTEST_ONLY(igt_evict_ctl.fail_if_busy))
208 return -EBUSY;
209
210 ret = ggtt_flush(dev_priv);
211 if (ret)
212 return ret;
213
214 cond_resched();
215
216 flags |= PIN_NONBLOCK;
217 goto search_again;
218
219found:
220 /* drm_mm doesn't allow any other other operations while
221 * scanning, therefore store to-be-evicted objects on a
222 * temporary list and take a reference for all before
223 * calling unbind (which may remove the active reference
224 * of any of our objects, thus corrupting the list).
225 */
226 list_for_each_entry_safe(vma, next, &eviction_list, evict_link) {
227 if (drm_mm_scan_remove_block(&scan, &vma->node))
228 __i915_vma_pin(vma);
229 else
230 list_del(&vma->evict_link);
231 }
232
233 /* Unbinding will emit any required flushes */
234 ret = 0;
235 list_for_each_entry_safe(vma, next, &eviction_list, evict_link) {
236 __i915_vma_unpin(vma);
237 if (ret == 0)
238 ret = i915_vma_unbind(vma);
239 }
240
241 while (ret == 0 && (node = drm_mm_scan_color_evict(&scan))) {
242 vma = container_of(node, struct i915_vma, node);
243 ret = i915_vma_unbind(vma);
244 }
245
246 return ret;
247}
248
249/**
250 * i915_gem_evict_for_vma - Evict vmas to make room for binding a new one
251 * @vm: address space to evict from
252 * @target: range (and color) to evict for
253 * @flags: additional flags to control the eviction algorithm
254 *
255 * This function will try to evict vmas that overlap the target node.
256 *
257 * To clarify: This is for freeing up virtual address space, not for freeing
258 * memory in e.g. the shrinker.
259 */
260int i915_gem_evict_for_node(struct i915_address_space *vm,
261 struct drm_mm_node *target,
262 unsigned int flags)
263{
264 LIST_HEAD(eviction_list);
265 struct drm_mm_node *node;
266 u64 start = target->start;
267 u64 end = start + target->size;
268 struct i915_vma *vma, *next;
269 bool check_color;
270 int ret = 0;
271
272 lockdep_assert_held(&vm->i915->drm.struct_mutex);
273 GEM_BUG_ON(!IS_ALIGNED(start, I915_GTT_PAGE_SIZE));
274 GEM_BUG_ON(!IS_ALIGNED(end, I915_GTT_PAGE_SIZE));
275
276 trace_i915_gem_evict_node(vm, target, flags);
277
278 /* Retire before we search the active list. Although we have
279 * reasonable accuracy in our retirement lists, we may have
280 * a stray pin (preventing eviction) that can only be resolved by
281 * retiring.
282 */
283 if (!(flags & PIN_NONBLOCK))
284 i915_retire_requests(vm->i915);
285
286 check_color = vm->mm.color_adjust;
287 if (check_color) {
288 /* Expand search to cover neighbouring guard pages (or lack!) */
289 if (start)
290 start -= I915_GTT_PAGE_SIZE;
291
292 /* Always look at the page afterwards to avoid the end-of-GTT */
293 end += I915_GTT_PAGE_SIZE;
294 }
295 GEM_BUG_ON(start >= end);
296
297 drm_mm_for_each_node_in_range(node, &vm->mm, start, end) {
298 /* If we find any non-objects (!vma), we cannot evict them */
299 if (node->color == I915_COLOR_UNEVICTABLE) {
300 ret = -ENOSPC;
301 break;
302 }
303
304 GEM_BUG_ON(!node->allocated);
305 vma = container_of(node, typeof(*vma), node);
306
307 /* If we are using coloring to insert guard pages between
308 * different cache domains within the address space, we have
309 * to check whether the objects on either side of our range
310 * abutt and conflict. If they are in conflict, then we evict
311 * those as well to make room for our guard pages.
312 */
313 if (check_color) {
314 if (node->start + node->size == target->start) {
315 if (node->color == target->color)
316 continue;
317 }
318 if (node->start == target->start + target->size) {
319 if (node->color == target->color)
320 continue;
321 }
322 }
323
324 if (flags & PIN_NONBLOCK &&
325 (i915_vma_is_pinned(vma) || i915_vma_is_active(vma))) {
326 ret = -ENOSPC;
327 break;
328 }
329
330 /* Overlap of objects in the same batch? */
331 if (i915_vma_is_pinned(vma)) {
332 ret = -ENOSPC;
333 if (vma->exec_flags &&
334 *vma->exec_flags & EXEC_OBJECT_PINNED)
335 ret = -EINVAL;
336 break;
337 }
338
339 /* Never show fear in the face of dragons!
340 *
341 * We cannot directly remove this node from within this
342 * iterator and as with i915_gem_evict_something() we employ
343 * the vma pin_count in order to prevent the action of
344 * unbinding one vma from freeing (by dropping its active
345 * reference) another in our eviction list.
346 */
347 __i915_vma_pin(vma);
348 list_add(&vma->evict_link, &eviction_list);
349 }
350
351 list_for_each_entry_safe(vma, next, &eviction_list, evict_link) {
352 __i915_vma_unpin(vma);
353 if (ret == 0)
354 ret = i915_vma_unbind(vma);
355 }
356
357 return ret;
358}
359
360/**
361 * i915_gem_evict_vm - Evict all idle vmas from a vm
362 * @vm: Address space to cleanse
363 *
364 * This function evicts all vmas from a vm.
365 *
366 * This is used by the execbuf code as a last-ditch effort to defragment the
367 * address space.
368 *
369 * To clarify: This is for freeing up virtual address space, not for freeing
370 * memory in e.g. the shrinker.
371 */
372int i915_gem_evict_vm(struct i915_address_space *vm)
373{
374 struct list_head eviction_list;
375 struct i915_vma *vma, *next;
376 int ret;
377
378 lockdep_assert_held(&vm->i915->drm.struct_mutex);
379 trace_i915_gem_evict_vm(vm);
380
381 /* Switch back to the default context in order to unpin
382 * the existing context objects. However, such objects only
383 * pin themselves inside the global GTT and performing the
384 * switch otherwise is ineffective.
385 */
386 if (i915_is_ggtt(vm)) {
387 ret = ggtt_flush(vm->i915);
388 if (ret)
389 return ret;
390 }
391
392 INIT_LIST_HEAD(&eviction_list);
393 mutex_lock(&vm->mutex);
394 list_for_each_entry(vma, &vm->bound_list, vm_link) {
395 if (i915_vma_is_pinned(vma))
396 continue;
397
398 __i915_vma_pin(vma);
399 list_add(&vma->evict_link, &eviction_list);
400 }
401 mutex_unlock(&vm->mutex);
402
403 ret = 0;
404 list_for_each_entry_safe(vma, next, &eviction_list, evict_link) {
405 __i915_vma_unpin(vma);
406 if (ret == 0)
407 ret = i915_vma_unbind(vma);
408 }
409 return ret;
410}
411
412#if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
413#include "selftests/i915_gem_evict.c"
414#endif