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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 "gem/i915_gem_context.h"
30#include "gt/intel_gt_requests.h"
31
32#include "i915_drv.h"
33#include "i915_trace.h"
34
35I915_SELFTEST_DECLARE(static struct igt_evict_ctl {
36 bool fail_if_busy:1;
37} igt_evict_ctl;)
38
39static int ggtt_flush(struct intel_gt *gt)
40{
41 /*
42 * Not everything in the GGTT is tracked via vma (otherwise we
43 * could evict as required with minimal stalling) so we are forced
44 * to idle the GPU and explicitly retire outstanding requests in
45 * the hopes that we can then remove contexts and the like only
46 * bound by their active reference.
47 */
48 return intel_gt_wait_for_idle(gt, MAX_SCHEDULE_TIMEOUT);
49}
50
51static bool
52mark_free(struct drm_mm_scan *scan,
53 struct i915_vma *vma,
54 unsigned int flags,
55 struct list_head *unwind)
56{
57 if (i915_vma_is_pinned(vma))
58 return false;
59
60 list_add(&vma->evict_link, unwind);
61 return drm_mm_scan_add_block(scan, &vma->node);
62}
63
64static bool defer_evict(struct i915_vma *vma)
65{
66 if (i915_vma_is_active(vma))
67 return true;
68
69 if (i915_vma_is_scanout(vma))
70 return true;
71
72 return false;
73}
74
75/**
76 * i915_gem_evict_something - Evict vmas to make room for binding a new one
77 * @vm: address space to evict from
78 * @min_size: size of the desired free space
79 * @alignment: alignment constraint of the desired free space
80 * @color: color for the desired space
81 * @start: start (inclusive) of the range from which to evict objects
82 * @end: end (exclusive) of the range from which to evict objects
83 * @flags: additional flags to control the eviction algorithm
84 *
85 * This function will try to evict vmas until a free space satisfying the
86 * requirements is found. Callers must check first whether any such hole exists
87 * already before calling this function.
88 *
89 * This function is used by the object/vma binding code.
90 *
91 * Since this function is only used to free up virtual address space it only
92 * ignores pinned vmas, and not object where the backing storage itself is
93 * pinned. Hence obj->pages_pin_count does not protect against eviction.
94 *
95 * To clarify: This is for freeing up virtual address space, not for freeing
96 * memory in e.g. the shrinker.
97 */
98int
99i915_gem_evict_something(struct i915_address_space *vm,
100 u64 min_size, u64 alignment,
101 unsigned long color,
102 u64 start, u64 end,
103 unsigned flags)
104{
105 struct drm_mm_scan scan;
106 struct list_head eviction_list;
107 struct i915_vma *vma, *next;
108 struct drm_mm_node *node;
109 enum drm_mm_insert_mode mode;
110 struct i915_vma *active;
111 int ret;
112
113 lockdep_assert_held(&vm->mutex);
114 trace_i915_gem_evict(vm, min_size, alignment, flags);
115
116 /*
117 * The goal is to evict objects and amalgamate space in rough LRU order.
118 * Since both active and inactive objects reside on the same list,
119 * in a mix of creation and last scanned order, as we process the list
120 * we sort it into inactive/active, which keeps the active portion
121 * in a rough MRU order.
122 *
123 * The retirement sequence is thus:
124 * 1. Inactive objects (already retired, random order)
125 * 2. Active objects (will stall on unbinding, oldest scanned first)
126 */
127 mode = DRM_MM_INSERT_BEST;
128 if (flags & PIN_HIGH)
129 mode = DRM_MM_INSERT_HIGH;
130 if (flags & PIN_MAPPABLE)
131 mode = DRM_MM_INSERT_LOW;
132 drm_mm_scan_init_with_range(&scan, &vm->mm,
133 min_size, alignment, color,
134 start, end, mode);
135
136 intel_gt_retire_requests(vm->gt);
137
138search_again:
139 active = NULL;
140 INIT_LIST_HEAD(&eviction_list);
141 list_for_each_entry_safe(vma, next, &vm->bound_list, vm_link) {
142 if (vma == active) { /* now seen this vma twice */
143 if (flags & PIN_NONBLOCK)
144 break;
145
146 active = ERR_PTR(-EAGAIN);
147 }
148
149 /*
150 * We keep this list in a rough least-recently scanned order
151 * of active elements (inactive elements are cheap to reap).
152 * New entries are added to the end, and we move anything we
153 * scan to the end. The assumption is that the working set
154 * of applications is either steady state (and thanks to the
155 * userspace bo cache it almost always is) or volatile and
156 * frequently replaced after a frame, which are self-evicting!
157 * Given that assumption, the MRU order of the scan list is
158 * fairly static, and keeping it in least-recently scan order
159 * is suitable.
160 *
161 * To notice when we complete one full cycle, we record the
162 * first active element seen, before moving it to the tail.
163 */
164 if (active != ERR_PTR(-EAGAIN) && defer_evict(vma)) {
165 if (!active)
166 active = vma;
167
168 list_move_tail(&vma->vm_link, &vm->bound_list);
169 continue;
170 }
171
172 if (mark_free(&scan, vma, flags, &eviction_list))
173 goto found;
174 }
175
176 /* Nothing found, clean up and bail out! */
177 list_for_each_entry_safe(vma, next, &eviction_list, evict_link) {
178 ret = drm_mm_scan_remove_block(&scan, &vma->node);
179 BUG_ON(ret);
180 }
181
182 /*
183 * Can we unpin some objects such as idle hw contents,
184 * or pending flips? But since only the GGTT has global entries
185 * such as scanouts, rinbuffers and contexts, we can skip the
186 * purge when inspecting per-process local address spaces.
187 */
188 if (!i915_is_ggtt(vm) || flags & PIN_NONBLOCK)
189 return -ENOSPC;
190
191 /*
192 * Not everything in the GGTT is tracked via VMA using
193 * i915_vma_move_to_active(), otherwise we could evict as required
194 * with minimal stalling. Instead we are forced to idle the GPU and
195 * explicitly retire outstanding requests which will then remove
196 * the pinning for active objects such as contexts and ring,
197 * enabling us to evict them on the next iteration.
198 *
199 * To ensure that all user contexts are evictable, we perform
200 * a switch to the perma-pinned kernel context. This all also gives
201 * us a termination condition, when the last retired context is
202 * the kernel's there is no more we can evict.
203 */
204 if (I915_SELFTEST_ONLY(igt_evict_ctl.fail_if_busy))
205 return -EBUSY;
206
207 ret = ggtt_flush(vm->gt);
208 if (ret)
209 return ret;
210
211 cond_resched();
212
213 flags |= PIN_NONBLOCK;
214 goto search_again;
215
216found:
217 /* drm_mm doesn't allow any other other operations while
218 * scanning, therefore store to-be-evicted objects on a
219 * temporary list and take a reference for all before
220 * calling unbind (which may remove the active reference
221 * of any of our objects, thus corrupting the list).
222 */
223 list_for_each_entry_safe(vma, next, &eviction_list, evict_link) {
224 if (drm_mm_scan_remove_block(&scan, &vma->node))
225 __i915_vma_pin(vma);
226 else
227 list_del(&vma->evict_link);
228 }
229
230 /* Unbinding will emit any required flushes */
231 ret = 0;
232 list_for_each_entry_safe(vma, next, &eviction_list, evict_link) {
233 __i915_vma_unpin(vma);
234 if (ret == 0)
235 ret = __i915_vma_unbind(vma);
236 }
237
238 while (ret == 0 && (node = drm_mm_scan_color_evict(&scan))) {
239 vma = container_of(node, struct i915_vma, node);
240
241 /* If we find any non-objects (!vma), we cannot evict them */
242 if (vma->node.color != I915_COLOR_UNEVICTABLE)
243 ret = __i915_vma_unbind(vma);
244 else
245 ret = -ENOSPC; /* XXX search failed, try again? */
246 }
247
248 return ret;
249}
250
251/**
252 * i915_gem_evict_for_node - Evict vmas to make room for binding a new one
253 * @vm: address space to evict from
254 * @target: range (and color) to evict for
255 * @flags: additional flags to control the eviction algorithm
256 *
257 * This function will try to evict vmas that overlap the target node.
258 *
259 * To clarify: This is for freeing up virtual address space, not for freeing
260 * memory in e.g. the shrinker.
261 */
262int i915_gem_evict_for_node(struct i915_address_space *vm,
263 struct drm_mm_node *target,
264 unsigned int flags)
265{
266 LIST_HEAD(eviction_list);
267 struct drm_mm_node *node;
268 u64 start = target->start;
269 u64 end = start + target->size;
270 struct i915_vma *vma, *next;
271 int ret = 0;
272
273 lockdep_assert_held(&vm->mutex);
274 GEM_BUG_ON(!IS_ALIGNED(start, I915_GTT_PAGE_SIZE));
275 GEM_BUG_ON(!IS_ALIGNED(end, I915_GTT_PAGE_SIZE));
276
277 trace_i915_gem_evict_node(vm, target, flags);
278
279 /*
280 * Retire before we search the active list. Although we have
281 * reasonable accuracy in our retirement lists, we may have
282 * a stray pin (preventing eviction) that can only be resolved by
283 * retiring.
284 */
285 intel_gt_retire_requests(vm->gt);
286
287 if (i915_vm_has_cache_coloring(vm)) {
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(!drm_mm_node_allocated(node));
305 vma = container_of(node, typeof(*vma), node);
306
307 /*
308 * If we are using coloring to insert guard pages between
309 * different cache domains within the address space, we have
310 * to check whether the objects on either side of our range
311 * abutt and conflict. If they are in conflict, then we evict
312 * those as well to make room for our guard pages.
313 */
314 if (i915_vm_has_cache_coloring(vm)) {
315 if (node->start + node->size == target->start) {
316 if (node->color == target->color)
317 continue;
318 }
319 if (node->start == target->start + target->size) {
320 if (node->color == target->color)
321 continue;
322 }
323 }
324
325 if (i915_vma_is_pinned(vma)) {
326 ret = -ENOSPC;
327 break;
328 }
329
330 if (flags & PIN_NONBLOCK && i915_vma_is_active(vma)) {
331 ret = -ENOSPC;
332 break;
333 }
334
335 /*
336 * Never show fear in the face of dragons!
337 *
338 * We cannot directly remove this node from within this
339 * iterator and as with i915_gem_evict_something() we employ
340 * the vma pin_count in order to prevent the action of
341 * unbinding one vma from freeing (by dropping its active
342 * reference) another in our eviction list.
343 */
344 __i915_vma_pin(vma);
345 list_add(&vma->evict_link, &eviction_list);
346 }
347
348 list_for_each_entry_safe(vma, next, &eviction_list, evict_link) {
349 __i915_vma_unpin(vma);
350 if (ret == 0)
351 ret = __i915_vma_unbind(vma);
352 }
353
354 return ret;
355}
356
357/**
358 * i915_gem_evict_vm - Evict all idle vmas from a vm
359 * @vm: Address space to cleanse
360 *
361 * This function evicts all vmas from a vm.
362 *
363 * This is used by the execbuf code as a last-ditch effort to defragment the
364 * address space.
365 *
366 * To clarify: This is for freeing up virtual address space, not for freeing
367 * memory in e.g. the shrinker.
368 */
369int i915_gem_evict_vm(struct i915_address_space *vm)
370{
371 int ret = 0;
372
373 lockdep_assert_held(&vm->mutex);
374 trace_i915_gem_evict_vm(vm);
375
376 /* Switch back to the default context in order to unpin
377 * the existing context objects. However, such objects only
378 * pin themselves inside the global GTT and performing the
379 * switch otherwise is ineffective.
380 */
381 if (i915_is_ggtt(vm)) {
382 ret = ggtt_flush(vm->gt);
383 if (ret)
384 return ret;
385 }
386
387 do {
388 struct i915_vma *vma, *vn;
389 LIST_HEAD(eviction_list);
390
391 list_for_each_entry(vma, &vm->bound_list, vm_link) {
392 if (i915_vma_is_pinned(vma))
393 continue;
394
395 __i915_vma_pin(vma);
396 list_add(&vma->evict_link, &eviction_list);
397 }
398 if (list_empty(&eviction_list))
399 break;
400
401 ret = 0;
402 list_for_each_entry_safe(vma, vn, &eviction_list, evict_link) {
403 __i915_vma_unpin(vma);
404 if (ret == 0)
405 ret = __i915_vma_unbind(vma);
406 if (ret != -EINTR) /* "Get me out of here!" */
407 ret = 0;
408 }
409 } while (ret == 0);
410
411 return ret;
412}
413
414#if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
415#include "selftests/i915_gem_evict.c"
416#endif
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}