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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 "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
64/**
65 * i915_gem_evict_something - Evict vmas to make room for binding a new one
66 * @vm: address space to evict from
67 * @min_size: size of the desired free space
68 * @alignment: alignment constraint of the desired free space
69 * @color: color for the desired space
70 * @start: start (inclusive) of the range from which to evict objects
71 * @end: end (exclusive) of the range from which to evict objects
72 * @flags: additional flags to control the eviction algorithm
73 *
74 * This function will try to evict vmas until a free space satisfying the
75 * requirements is found. Callers must check first whether any such hole exists
76 * already before calling this function.
77 *
78 * This function is used by the object/vma binding code.
79 *
80 * Since this function is only used to free up virtual address space it only
81 * ignores pinned vmas, and not object where the backing storage itself is
82 * pinned. Hence obj->pages_pin_count does not protect against eviction.
83 *
84 * To clarify: This is for freeing up virtual address space, not for freeing
85 * memory in e.g. the shrinker.
86 */
87int
88i915_gem_evict_something(struct i915_address_space *vm,
89 u64 min_size, u64 alignment,
90 unsigned long color,
91 u64 start, u64 end,
92 unsigned flags)
93{
94 struct drm_mm_scan scan;
95 struct list_head eviction_list;
96 struct i915_vma *vma, *next;
97 struct drm_mm_node *node;
98 enum drm_mm_insert_mode mode;
99 struct i915_vma *active;
100 int ret;
101
102 lockdep_assert_held(&vm->mutex);
103 trace_i915_gem_evict(vm, min_size, alignment, flags);
104
105 /*
106 * The goal is to evict objects and amalgamate space in rough LRU order.
107 * Since both active and inactive objects reside on the same list,
108 * in a mix of creation and last scanned order, as we process the list
109 * we sort it into inactive/active, which keeps the active portion
110 * in a rough MRU order.
111 *
112 * The retirement sequence is thus:
113 * 1. Inactive objects (already retired, random order)
114 * 2. Active objects (will stall on unbinding, oldest scanned first)
115 */
116 mode = DRM_MM_INSERT_BEST;
117 if (flags & PIN_HIGH)
118 mode = DRM_MM_INSERT_HIGH;
119 if (flags & PIN_MAPPABLE)
120 mode = DRM_MM_INSERT_LOW;
121 drm_mm_scan_init_with_range(&scan, &vm->mm,
122 min_size, alignment, color,
123 start, end, mode);
124
125 intel_gt_retire_requests(vm->gt);
126
127search_again:
128 active = NULL;
129 INIT_LIST_HEAD(&eviction_list);
130 list_for_each_entry_safe(vma, next, &vm->bound_list, vm_link) {
131 if (vma == active) { /* now seen this vma twice */
132 if (flags & PIN_NONBLOCK)
133 break;
134
135 active = ERR_PTR(-EAGAIN);
136 }
137
138 /*
139 * We keep this list in a rough least-recently scanned order
140 * of active elements (inactive elements are cheap to reap).
141 * New entries are added to the end, and we move anything we
142 * scan to the end. The assumption is that the working set
143 * of applications is either steady state (and thanks to the
144 * userspace bo cache it almost always is) or volatile and
145 * frequently replaced after a frame, which are self-evicting!
146 * Given that assumption, the MRU order of the scan list is
147 * fairly static, and keeping it in least-recently scan order
148 * is suitable.
149 *
150 * To notice when we complete one full cycle, we record the
151 * first active element seen, before moving it to the tail.
152 */
153 if (active != ERR_PTR(-EAGAIN) && i915_vma_is_active(vma)) {
154 if (!active)
155 active = vma;
156
157 list_move_tail(&vma->vm_link, &vm->bound_list);
158 continue;
159 }
160
161 if (mark_free(&scan, vma, flags, &eviction_list))
162 goto found;
163 }
164
165 /* Nothing found, clean up and bail out! */
166 list_for_each_entry_safe(vma, next, &eviction_list, evict_link) {
167 ret = drm_mm_scan_remove_block(&scan, &vma->node);
168 BUG_ON(ret);
169 }
170
171 /*
172 * Can we unpin some objects such as idle hw contents,
173 * or pending flips? But since only the GGTT has global entries
174 * such as scanouts, rinbuffers and contexts, we can skip the
175 * purge when inspecting per-process local address spaces.
176 */
177 if (!i915_is_ggtt(vm) || flags & PIN_NONBLOCK)
178 return -ENOSPC;
179
180 /*
181 * Not everything in the GGTT is tracked via VMA using
182 * i915_vma_move_to_active(), otherwise we could evict as required
183 * with minimal stalling. Instead we are forced to idle the GPU and
184 * explicitly retire outstanding requests which will then remove
185 * the pinning for active objects such as contexts and ring,
186 * enabling us to evict them on the next iteration.
187 *
188 * To ensure that all user contexts are evictable, we perform
189 * a switch to the perma-pinned kernel context. This all also gives
190 * us a termination condition, when the last retired context is
191 * the kernel's there is no more we can evict.
192 */
193 if (I915_SELFTEST_ONLY(igt_evict_ctl.fail_if_busy))
194 return -EBUSY;
195
196 ret = ggtt_flush(vm->gt);
197 if (ret)
198 return ret;
199
200 cond_resched();
201
202 flags |= PIN_NONBLOCK;
203 goto search_again;
204
205found:
206 /* drm_mm doesn't allow any other other operations while
207 * scanning, therefore store to-be-evicted objects on a
208 * temporary list and take a reference for all before
209 * calling unbind (which may remove the active reference
210 * of any of our objects, thus corrupting the list).
211 */
212 list_for_each_entry_safe(vma, next, &eviction_list, evict_link) {
213 if (drm_mm_scan_remove_block(&scan, &vma->node))
214 __i915_vma_pin(vma);
215 else
216 list_del(&vma->evict_link);
217 }
218
219 /* Unbinding will emit any required flushes */
220 ret = 0;
221 list_for_each_entry_safe(vma, next, &eviction_list, evict_link) {
222 __i915_vma_unpin(vma);
223 if (ret == 0)
224 ret = __i915_vma_unbind(vma);
225 }
226
227 while (ret == 0 && (node = drm_mm_scan_color_evict(&scan))) {
228 vma = container_of(node, struct i915_vma, node);
229
230 /* If we find any non-objects (!vma), we cannot evict them */
231 if (vma->node.color != I915_COLOR_UNEVICTABLE)
232 ret = __i915_vma_unbind(vma);
233 else
234 ret = -ENOSPC; /* XXX search failed, try again? */
235 }
236
237 return ret;
238}
239
240/**
241 * i915_gem_evict_for_vma - Evict vmas to make room for binding a new one
242 * @vm: address space to evict from
243 * @target: range (and color) to evict for
244 * @flags: additional flags to control the eviction algorithm
245 *
246 * This function will try to evict vmas that overlap the target node.
247 *
248 * To clarify: This is for freeing up virtual address space, not for freeing
249 * memory in e.g. the shrinker.
250 */
251int i915_gem_evict_for_node(struct i915_address_space *vm,
252 struct drm_mm_node *target,
253 unsigned int flags)
254{
255 LIST_HEAD(eviction_list);
256 struct drm_mm_node *node;
257 u64 start = target->start;
258 u64 end = start + target->size;
259 struct i915_vma *vma, *next;
260 int ret = 0;
261
262 lockdep_assert_held(&vm->mutex);
263 GEM_BUG_ON(!IS_ALIGNED(start, I915_GTT_PAGE_SIZE));
264 GEM_BUG_ON(!IS_ALIGNED(end, I915_GTT_PAGE_SIZE));
265
266 trace_i915_gem_evict_node(vm, target, flags);
267
268 /*
269 * Retire before we search the active list. Although we have
270 * reasonable accuracy in our retirement lists, we may have
271 * a stray pin (preventing eviction) that can only be resolved by
272 * retiring.
273 */
274 intel_gt_retire_requests(vm->gt);
275
276 if (i915_vm_has_cache_coloring(vm)) {
277 /* Expand search to cover neighbouring guard pages (or lack!) */
278 if (start)
279 start -= I915_GTT_PAGE_SIZE;
280
281 /* Always look at the page afterwards to avoid the end-of-GTT */
282 end += I915_GTT_PAGE_SIZE;
283 }
284 GEM_BUG_ON(start >= end);
285
286 drm_mm_for_each_node_in_range(node, &vm->mm, start, end) {
287 /* If we find any non-objects (!vma), we cannot evict them */
288 if (node->color == I915_COLOR_UNEVICTABLE) {
289 ret = -ENOSPC;
290 break;
291 }
292
293 GEM_BUG_ON(!drm_mm_node_allocated(node));
294 vma = container_of(node, typeof(*vma), node);
295
296 /*
297 * If we are using coloring to insert guard pages between
298 * different cache domains within the address space, we have
299 * to check whether the objects on either side of our range
300 * abutt and conflict. If they are in conflict, then we evict
301 * those as well to make room for our guard pages.
302 */
303 if (i915_vm_has_cache_coloring(vm)) {
304 if (node->start + node->size == target->start) {
305 if (node->color == target->color)
306 continue;
307 }
308 if (node->start == target->start + target->size) {
309 if (node->color == target->color)
310 continue;
311 }
312 }
313
314 if (i915_vma_is_pinned(vma)) {
315 ret = -ENOSPC;
316 break;
317 }
318
319 if (flags & PIN_NONBLOCK && i915_vma_is_active(vma)) {
320 ret = -ENOSPC;
321 break;
322 }
323
324 /*
325 * Never show fear in the face of dragons!
326 *
327 * We cannot directly remove this node from within this
328 * iterator and as with i915_gem_evict_something() we employ
329 * the vma pin_count in order to prevent the action of
330 * unbinding one vma from freeing (by dropping its active
331 * reference) another in our eviction list.
332 */
333 __i915_vma_pin(vma);
334 list_add(&vma->evict_link, &eviction_list);
335 }
336
337 list_for_each_entry_safe(vma, next, &eviction_list, evict_link) {
338 __i915_vma_unpin(vma);
339 if (ret == 0)
340 ret = __i915_vma_unbind(vma);
341 }
342
343 return ret;
344}
345
346/**
347 * i915_gem_evict_vm - Evict all idle vmas from a vm
348 * @vm: Address space to cleanse
349 *
350 * This function evicts all vmas from a vm.
351 *
352 * This is used by the execbuf code as a last-ditch effort to defragment the
353 * address space.
354 *
355 * To clarify: This is for freeing up virtual address space, not for freeing
356 * memory in e.g. the shrinker.
357 */
358int i915_gem_evict_vm(struct i915_address_space *vm)
359{
360 int ret = 0;
361
362 lockdep_assert_held(&vm->mutex);
363 trace_i915_gem_evict_vm(vm);
364
365 /* Switch back to the default context in order to unpin
366 * the existing context objects. However, such objects only
367 * pin themselves inside the global GTT and performing the
368 * switch otherwise is ineffective.
369 */
370 if (i915_is_ggtt(vm)) {
371 ret = ggtt_flush(vm->gt);
372 if (ret)
373 return ret;
374 }
375
376 do {
377 struct i915_vma *vma, *vn;
378 LIST_HEAD(eviction_list);
379
380 list_for_each_entry(vma, &vm->bound_list, vm_link) {
381 if (i915_vma_is_pinned(vma))
382 continue;
383
384 __i915_vma_pin(vma);
385 list_add(&vma->evict_link, &eviction_list);
386 }
387 if (list_empty(&eviction_list))
388 break;
389
390 ret = 0;
391 list_for_each_entry_safe(vma, vn, &eviction_list, evict_link) {
392 __i915_vma_unpin(vma);
393 if (ret == 0)
394 ret = __i915_vma_unbind(vma);
395 if (ret != -EINTR) /* "Get me out of here!" */
396 ret = 0;
397 }
398 } while (ret == 0);
399
400 return ret;
401}
402
403#if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
404#include "selftests/i915_gem_evict.c"
405#endif