2 * Copyright © 2008-2010 Intel Corporation
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:
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
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
24 * Eric Anholt <eric@anholt.net>
25 * Chris Wilson <chris@chris-wilson.co.uuk>
30 #include <drm/i915_drm.h>
33 #include "intel_drv.h"
34 #include "i915_trace.h"
36 I915_SELFTEST_DECLARE(static struct igt_evict_ctl {
40 static bool ggtt_is_idle(struct drm_i915_private *i915)
42 struct intel_engine_cs *engine;
43 enum intel_engine_id id;
45 if (i915->gt.active_requests)
48 for_each_engine(engine, i915, id) {
49 if (engine->last_retired_context != i915->kernel_context)
56 static int ggtt_flush(struct drm_i915_private *i915)
60 /* Not everything in the GGTT is tracked via vma (otherwise we
61 * could evict as required with minimal stalling) so we are forced
62 * to idle the GPU and explicitly retire outstanding requests in
63 * the hopes that we can then remove contexts and the like only
64 * bound by their active reference.
66 err = i915_gem_switch_to_kernel_context(i915);
70 err = i915_gem_wait_for_idle(i915,
71 I915_WAIT_INTERRUPTIBLE |
80 mark_free(struct drm_mm_scan *scan,
83 struct list_head *unwind)
85 if (i915_vma_is_pinned(vma))
88 if (flags & PIN_NONFAULT && i915_vma_has_userfault(vma))
91 list_add(&vma->evict_link, unwind);
92 return drm_mm_scan_add_block(scan, &vma->node);
96 * i915_gem_evict_something - Evict vmas to make room for binding a new one
97 * @vm: address space to evict from
98 * @min_size: size of the desired free space
99 * @alignment: alignment constraint of the desired free space
100 * @cache_level: cache_level for the desired space
101 * @start: start (inclusive) of the range from which to evict objects
102 * @end: end (exclusive) of the range from which to evict objects
103 * @flags: additional flags to control the eviction algorithm
105 * This function will try to evict vmas until a free space satisfying the
106 * requirements is found. Callers must check first whether any such hole exists
107 * already before calling this function.
109 * This function is used by the object/vma binding code.
111 * Since this function is only used to free up virtual address space it only
112 * ignores pinned vmas, and not object where the backing storage itself is
113 * pinned. Hence obj->pages_pin_count does not protect against eviction.
115 * To clarify: This is for freeing up virtual address space, not for freeing
116 * memory in e.g. the shrinker.
119 i915_gem_evict_something(struct i915_address_space *vm,
120 u64 min_size, u64 alignment,
121 unsigned cache_level,
125 struct drm_i915_private *dev_priv = vm->i915;
126 struct drm_mm_scan scan;
127 struct list_head eviction_list;
128 struct list_head *phases[] = {
133 struct i915_vma *vma, *next;
134 struct drm_mm_node *node;
135 enum drm_mm_insert_mode mode;
138 lockdep_assert_held(&vm->i915->drm.struct_mutex);
139 trace_i915_gem_evict(vm, min_size, alignment, flags);
142 * The goal is to evict objects and amalgamate space in LRU order.
143 * The oldest idle objects reside on the inactive list, which is in
144 * retirement order. The next objects to retire are those in flight,
145 * on the active list, again in retirement order.
147 * The retirement sequence is thus:
148 * 1. Inactive objects (already retired)
149 * 2. Active objects (will stall on unbinding)
151 * On each list, the oldest objects lie at the HEAD with the freshest
152 * object on the TAIL.
154 mode = DRM_MM_INSERT_BEST;
155 if (flags & PIN_HIGH)
156 mode = DRM_MM_INSERT_HIGH;
157 if (flags & PIN_MAPPABLE)
158 mode = DRM_MM_INSERT_LOW;
159 drm_mm_scan_init_with_range(&scan, &vm->mm,
160 min_size, alignment, cache_level,
164 * Retire before we search the active list. Although we have
165 * reasonable accuracy in our retirement lists, we may have
166 * a stray pin (preventing eviction) that can only be resolved by
169 if (!(flags & PIN_NONBLOCK))
170 i915_gem_retire_requests(dev_priv);
175 INIT_LIST_HEAD(&eviction_list);
178 list_for_each_entry(vma, *phase, vm_link)
179 if (mark_free(&scan, vma, flags, &eviction_list))
183 /* Nothing found, clean up and bail out! */
184 list_for_each_entry_safe(vma, next, &eviction_list, evict_link) {
185 ret = drm_mm_scan_remove_block(&scan, &vma->node);
190 * Can we unpin some objects such as idle hw contents,
191 * or pending flips? But since only the GGTT has global entries
192 * such as scanouts, rinbuffers and contexts, we can skip the
193 * purge when inspecting per-process local address spaces.
195 if (!i915_is_ggtt(vm) || flags & PIN_NONBLOCK)
199 * Not everything in the GGTT is tracked via VMA using
200 * i915_vma_move_to_active(), otherwise we could evict as required
201 * with minimal stalling. Instead we are forced to idle the GPU and
202 * explicitly retire outstanding requests which will then remove
203 * the pinning for active objects such as contexts and ring,
204 * enabling us to evict them on the next iteration.
206 * To ensure that all user contexts are evictable, we perform
207 * a switch to the perma-pinned kernel context. This all also gives
208 * us a termination condition, when the last retired context is
209 * the kernel's there is no more we can evict.
211 if (!ggtt_is_idle(dev_priv)) {
212 if (I915_SELFTEST_ONLY(igt_evict_ctl.fail_if_busy))
215 ret = ggtt_flush(dev_priv);
223 * If we still have pending pageflip completions, drop
224 * back to userspace to give our workqueues time to
225 * acquire our locks and unpin the old scanouts.
227 return intel_has_pending_fb_unpin(dev_priv) ? -EAGAIN : -ENOSPC;
230 /* drm_mm doesn't allow any other other operations while
231 * scanning, therefore store to-be-evicted objects on a
232 * temporary list and take a reference for all before
233 * calling unbind (which may remove the active reference
234 * of any of our objects, thus corrupting the list).
236 list_for_each_entry_safe(vma, next, &eviction_list, evict_link) {
237 if (drm_mm_scan_remove_block(&scan, &vma->node))
240 list_del(&vma->evict_link);
243 /* Unbinding will emit any required flushes */
245 list_for_each_entry_safe(vma, next, &eviction_list, evict_link) {
246 __i915_vma_unpin(vma);
248 ret = i915_vma_unbind(vma);
251 while (ret == 0 && (node = drm_mm_scan_color_evict(&scan))) {
252 vma = container_of(node, struct i915_vma, node);
253 ret = i915_vma_unbind(vma);
260 * i915_gem_evict_for_vma - Evict vmas to make room for binding a new one
261 * @vm: address space to evict from
262 * @target: range (and color) to evict for
263 * @flags: additional flags to control the eviction algorithm
265 * This function will try to evict vmas that overlap the target node.
267 * To clarify: This is for freeing up virtual address space, not for freeing
268 * memory in e.g. the shrinker.
270 int i915_gem_evict_for_node(struct i915_address_space *vm,
271 struct drm_mm_node *target,
274 LIST_HEAD(eviction_list);
275 struct drm_mm_node *node;
276 u64 start = target->start;
277 u64 end = start + target->size;
278 struct i915_vma *vma, *next;
282 lockdep_assert_held(&vm->i915->drm.struct_mutex);
283 GEM_BUG_ON(!IS_ALIGNED(start, I915_GTT_PAGE_SIZE));
284 GEM_BUG_ON(!IS_ALIGNED(end, I915_GTT_PAGE_SIZE));
286 trace_i915_gem_evict_node(vm, target, flags);
288 /* Retire before we search the active list. Although we have
289 * reasonable accuracy in our retirement lists, we may have
290 * a stray pin (preventing eviction) that can only be resolved by
293 if (!(flags & PIN_NONBLOCK))
294 i915_gem_retire_requests(vm->i915);
296 check_color = vm->mm.color_adjust;
298 /* Expand search to cover neighbouring guard pages (or lack!) */
300 start -= I915_GTT_PAGE_SIZE;
302 /* Always look at the page afterwards to avoid the end-of-GTT */
303 end += I915_GTT_PAGE_SIZE;
305 GEM_BUG_ON(start >= end);
307 drm_mm_for_each_node_in_range(node, &vm->mm, start, end) {
308 /* If we find any non-objects (!vma), we cannot evict them */
309 if (node->color == I915_COLOR_UNEVICTABLE) {
314 GEM_BUG_ON(!node->allocated);
315 vma = container_of(node, typeof(*vma), node);
317 /* If we are using coloring to insert guard pages between
318 * different cache domains within the address space, we have
319 * to check whether the objects on either side of our range
320 * abutt and conflict. If they are in conflict, then we evict
321 * those as well to make room for our guard pages.
324 if (node->start + node->size == target->start) {
325 if (node->color == target->color)
328 if (node->start == target->start + target->size) {
329 if (node->color == target->color)
334 if (flags & PIN_NONBLOCK &&
335 (i915_vma_is_pinned(vma) || i915_vma_is_active(vma))) {
340 if (flags & PIN_NONFAULT && i915_vma_has_userfault(vma)) {
345 /* Overlap of objects in the same batch? */
346 if (i915_vma_is_pinned(vma)) {
348 if (vma->exec_flags &&
349 *vma->exec_flags & EXEC_OBJECT_PINNED)
354 /* Never show fear in the face of dragons!
356 * We cannot directly remove this node from within this
357 * iterator and as with i915_gem_evict_something() we employ
358 * the vma pin_count in order to prevent the action of
359 * unbinding one vma from freeing (by dropping its active
360 * reference) another in our eviction list.
363 list_add(&vma->evict_link, &eviction_list);
366 list_for_each_entry_safe(vma, next, &eviction_list, evict_link) {
367 __i915_vma_unpin(vma);
369 ret = i915_vma_unbind(vma);
376 * i915_gem_evict_vm - Evict all idle vmas from a vm
377 * @vm: Address space to cleanse
379 * This function evicts all vmas from a vm.
381 * This is used by the execbuf code as a last-ditch effort to defragment the
384 * To clarify: This is for freeing up virtual address space, not for freeing
385 * memory in e.g. the shrinker.
387 int i915_gem_evict_vm(struct i915_address_space *vm)
389 struct list_head *phases[] = {
394 struct list_head eviction_list;
395 struct i915_vma *vma, *next;
398 lockdep_assert_held(&vm->i915->drm.struct_mutex);
399 trace_i915_gem_evict_vm(vm);
401 /* Switch back to the default context in order to unpin
402 * the existing context objects. However, such objects only
403 * pin themselves inside the global GTT and performing the
404 * switch otherwise is ineffective.
406 if (i915_is_ggtt(vm)) {
407 ret = ggtt_flush(vm->i915);
412 INIT_LIST_HEAD(&eviction_list);
415 list_for_each_entry(vma, *phase, vm_link) {
416 if (i915_vma_is_pinned(vma))
420 list_add(&vma->evict_link, &eviction_list);
425 list_for_each_entry_safe(vma, next, &eviction_list, evict_link) {
426 __i915_vma_unpin(vma);
428 ret = i915_vma_unbind(vma);
433 #if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
434 #include "selftests/i915_gem_evict.c"