1/*
  2 * Copyright © 2017 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 */
 24
 25#include <linux/sched/mm.h>
 26
 27#include "display/intel_frontbuffer.h"
 28#include "gt/intel_gt.h"
 29#include "i915_drv.h"
 30#include "i915_gem_clflush.h"
 31#include "i915_gem_context.h"
 32#include "i915_gem_mman.h"
 33#include "i915_gem_object.h"
 34#include "i915_globals.h"
 35#include "i915_trace.h"
 36
 37static struct i915_global_object {
 38	struct i915_global base;
 39	struct kmem_cache *slab_objects;
 40} global;
 41
 42struct drm_i915_gem_object *i915_gem_object_alloc(void)
 43{
 44	return kmem_cache_zalloc(global.slab_objects, GFP_KERNEL);
 45}
 46
 47void i915_gem_object_free(struct drm_i915_gem_object *obj)
 48{
 49	return kmem_cache_free(global.slab_objects, obj);
 50}
 51
 52void i915_gem_object_init(struct drm_i915_gem_object *obj,
 53			  const struct drm_i915_gem_object_ops *ops,
 54			  struct lock_class_key *key)
 55{
 56	__mutex_init(&obj->mm.lock, ops->name ?: "obj->mm.lock", key);
 57
 58	spin_lock_init(&obj->vma.lock);
 59	INIT_LIST_HEAD(&obj->vma.list);
 60
 61	INIT_LIST_HEAD(&obj->mm.link);
 62
 63	INIT_LIST_HEAD(&obj->lut_list);
 64	spin_lock_init(&obj->lut_lock);
 65
 66	spin_lock_init(&obj->mmo.lock);
 67	obj->mmo.offsets = RB_ROOT;
 68
 69	init_rcu_head(&obj->rcu);
 70
 71	obj->ops = ops;
 72
 73	obj->mm.madv = I915_MADV_WILLNEED;
 74	INIT_RADIX_TREE(&obj->mm.get_page.radix, GFP_KERNEL | __GFP_NOWARN);
 75	mutex_init(&obj->mm.get_page.lock);
 76
 77	if (IS_ENABLED(CONFIG_LOCKDEP) && i915_gem_object_is_shrinkable(obj))
 78		i915_gem_shrinker_taints_mutex(to_i915(obj->base.dev),
 79					       &obj->mm.lock);
 80}
 81
 82/**
 83 * Mark up the object's coherency levels for a given cache_level
 84 * @obj: #drm_i915_gem_object
 85 * @cache_level: cache level
 86 */
 87void i915_gem_object_set_cache_coherency(struct drm_i915_gem_object *obj,
 88					 unsigned int cache_level)
 89{
 90	obj->cache_level = cache_level;
 91
 92	if (cache_level != I915_CACHE_NONE)
 93		obj->cache_coherent = (I915_BO_CACHE_COHERENT_FOR_READ |
 94				       I915_BO_CACHE_COHERENT_FOR_WRITE);
 95	else if (HAS_LLC(to_i915(obj->base.dev)))
 96		obj->cache_coherent = I915_BO_CACHE_COHERENT_FOR_READ;
 97	else
 98		obj->cache_coherent = 0;
 99
100	obj->cache_dirty =
101		!(obj->cache_coherent & I915_BO_CACHE_COHERENT_FOR_WRITE);
102}
103
104void i915_gem_close_object(struct drm_gem_object *gem, struct drm_file *file)
105{
106	struct drm_i915_gem_object *obj = to_intel_bo(gem);
107	struct drm_i915_file_private *fpriv = file->driver_priv;
108	struct i915_lut_handle bookmark = {};
109	struct i915_mmap_offset *mmo, *mn;
110	struct i915_lut_handle *lut, *ln;
111	LIST_HEAD(close);
112
113	spin_lock(&obj->lut_lock);
114	list_for_each_entry_safe(lut, ln, &obj->lut_list, obj_link) {
115		struct i915_gem_context *ctx = lut->ctx;
116
117		if (ctx && ctx->file_priv == fpriv) {
118			i915_gem_context_get(ctx);
119			list_move(&lut->obj_link, &close);
120		}
121
122		/* Break long locks, and carefully continue on from this spot */
123		if (&ln->obj_link != &obj->lut_list) {
124			list_add_tail(&bookmark.obj_link, &ln->obj_link);
125			if (cond_resched_lock(&obj->lut_lock))
126				list_safe_reset_next(&bookmark, ln, obj_link);
127			__list_del_entry(&bookmark.obj_link);
128		}
129	}
130	spin_unlock(&obj->lut_lock);
131
132	spin_lock(&obj->mmo.lock);
133	rbtree_postorder_for_each_entry_safe(mmo, mn, &obj->mmo.offsets, offset)
134		drm_vma_node_revoke(&mmo->vma_node, file);
135	spin_unlock(&obj->mmo.lock);
136
137	list_for_each_entry_safe(lut, ln, &close, obj_link) {
138		struct i915_gem_context *ctx = lut->ctx;
139		struct i915_vma *vma;
140
141		/*
142		 * We allow the process to have multiple handles to the same
143		 * vma, in the same fd namespace, by virtue of flink/open.
144		 */
145
146		mutex_lock(&ctx->lut_mutex);
147		vma = radix_tree_delete(&ctx->handles_vma, lut->handle);
148		if (vma) {
149			GEM_BUG_ON(vma->obj != obj);
150			GEM_BUG_ON(!atomic_read(&vma->open_count));
151			i915_vma_close(vma);
152		}
153		mutex_unlock(&ctx->lut_mutex);
154
155		i915_gem_context_put(lut->ctx);
156		i915_lut_handle_free(lut);
157		i915_gem_object_put(obj);
158	}
159}
160
161static void __i915_gem_free_object_rcu(struct rcu_head *head)
162{
163	struct drm_i915_gem_object *obj =
164		container_of(head, typeof(*obj), rcu);
165	struct drm_i915_private *i915 = to_i915(obj->base.dev);
166
167	dma_resv_fini(&obj->base._resv);
168	i915_gem_object_free(obj);
169
170	GEM_BUG_ON(!atomic_read(&i915->mm.free_count));
171	atomic_dec(&i915->mm.free_count);
172}
173
174static void __i915_gem_object_free_mmaps(struct drm_i915_gem_object *obj)
175{
176	/* Skip serialisation and waking the device if known to be not used. */
177
178	if (obj->userfault_count)
179		i915_gem_object_release_mmap_gtt(obj);
180
181	if (!RB_EMPTY_ROOT(&obj->mmo.offsets)) {
182		struct i915_mmap_offset *mmo, *mn;
183
184		i915_gem_object_release_mmap_offset(obj);
185
186		rbtree_postorder_for_each_entry_safe(mmo, mn,
187						     &obj->mmo.offsets,
188						     offset) {
189			drm_vma_offset_remove(obj->base.dev->vma_offset_manager,
190					      &mmo->vma_node);
191			kfree(mmo);
192		}
193		obj->mmo.offsets = RB_ROOT;
194	}
195}
196
197static void __i915_gem_free_objects(struct drm_i915_private *i915,
198				    struct llist_node *freed)
199{
200	struct drm_i915_gem_object *obj, *on;
201
202	llist_for_each_entry_safe(obj, on, freed, freed) {
203		trace_i915_gem_object_destroy(obj);
204
205		if (!list_empty(&obj->vma.list)) {
206			struct i915_vma *vma;
207
208			/*
209			 * Note that the vma keeps an object reference while
210			 * it is active, so it *should* not sleep while we
211			 * destroy it. Our debug code errs insits it *might*.
212			 * For the moment, play along.
213			 */
214			spin_lock(&obj->vma.lock);
215			while ((vma = list_first_entry_or_null(&obj->vma.list,
216							       struct i915_vma,
217							       obj_link))) {
218				GEM_BUG_ON(vma->obj != obj);
219				spin_unlock(&obj->vma.lock);
220
221				__i915_vma_put(vma);
222
223				spin_lock(&obj->vma.lock);
224			}
225			spin_unlock(&obj->vma.lock);
226		}
227
228		__i915_gem_object_free_mmaps(obj);
229
230		GEM_BUG_ON(!list_empty(&obj->lut_list));
231
232		atomic_set(&obj->mm.pages_pin_count, 0);
233		__i915_gem_object_put_pages(obj);
234		GEM_BUG_ON(i915_gem_object_has_pages(obj));
235		bitmap_free(obj->bit_17);
236
237		if (obj->base.import_attach)
238			drm_prime_gem_destroy(&obj->base, NULL);
239
240		drm_gem_free_mmap_offset(&obj->base);
241
242		if (obj->ops->release)
243			obj->ops->release(obj);
244
245		/* But keep the pointer alive for RCU-protected lookups */
246		call_rcu(&obj->rcu, __i915_gem_free_object_rcu);
247		cond_resched();
248	}
249}
250
251void i915_gem_flush_free_objects(struct drm_i915_private *i915)
252{
253	struct llist_node *freed = llist_del_all(&i915->mm.free_list);
254
255	if (unlikely(freed))
256		__i915_gem_free_objects(i915, freed);
257}
258
259static void __i915_gem_free_work(struct work_struct *work)
260{
261	struct drm_i915_private *i915 =
262		container_of(work, struct drm_i915_private, mm.free_work);
263
264	i915_gem_flush_free_objects(i915);
265}
266
267void i915_gem_free_object(struct drm_gem_object *gem_obj)
268{
269	struct drm_i915_gem_object *obj = to_intel_bo(gem_obj);
270	struct drm_i915_private *i915 = to_i915(obj->base.dev);
271
272	GEM_BUG_ON(i915_gem_object_is_framebuffer(obj));
273
274	/*
275	 * Before we free the object, make sure any pure RCU-only
276	 * read-side critical sections are complete, e.g.
277	 * i915_gem_busy_ioctl(). For the corresponding synchronized
278	 * lookup see i915_gem_object_lookup_rcu().
279	 */
280	atomic_inc(&i915->mm.free_count);
281
282	/*
283	 * This serializes freeing with the shrinker. Since the free
284	 * is delayed, first by RCU then by the workqueue, we want the
285	 * shrinker to be able to free pages of unreferenced objects,
286	 * or else we may oom whilst there are plenty of deferred
287	 * freed objects.
288	 */
289	i915_gem_object_make_unshrinkable(obj);
290
291	/*
292	 * Since we require blocking on struct_mutex to unbind the freed
293	 * object from the GPU before releasing resources back to the
294	 * system, we can not do that directly from the RCU callback (which may
295	 * be a softirq context), but must instead then defer that work onto a
296	 * kthread. We use the RCU callback rather than move the freed object
297	 * directly onto the work queue so that we can mix between using the
298	 * worker and performing frees directly from subsequent allocations for
299	 * crude but effective memory throttling.
300	 */
301	if (llist_add(&obj->freed, &i915->mm.free_list))
302		queue_work(i915->wq, &i915->mm.free_work);
303}
304
305static bool gpu_write_needs_clflush(struct drm_i915_gem_object *obj)
306{
307	return !(obj->cache_level == I915_CACHE_NONE ||
308		 obj->cache_level == I915_CACHE_WT);
309}
310
311void
312i915_gem_object_flush_write_domain(struct drm_i915_gem_object *obj,
313				   unsigned int flush_domains)
314{
315	struct i915_vma *vma;
316
317	assert_object_held(obj);
318
319	if (!(obj->write_domain & flush_domains))
320		return;
321
322	switch (obj->write_domain) {
323	case I915_GEM_DOMAIN_GTT:
324		spin_lock(&obj->vma.lock);
325		for_each_ggtt_vma(vma, obj) {
326			if (i915_vma_unset_ggtt_write(vma))
327				intel_gt_flush_ggtt_writes(vma->vm->gt);
328		}
329		spin_unlock(&obj->vma.lock);
330
331		i915_gem_object_flush_frontbuffer(obj, ORIGIN_CPU);
332		break;
333
334	case I915_GEM_DOMAIN_WC:
335		wmb();
336		break;
337
338	case I915_GEM_DOMAIN_CPU:
339		i915_gem_clflush_object(obj, I915_CLFLUSH_SYNC);
340		break;
341
342	case I915_GEM_DOMAIN_RENDER:
343		if (gpu_write_needs_clflush(obj))
344			obj->cache_dirty = true;
345		break;
346	}
347
348	obj->write_domain = 0;
349}
350
351void __i915_gem_object_flush_frontbuffer(struct drm_i915_gem_object *obj,
352					 enum fb_op_origin origin)
353{
354	struct intel_frontbuffer *front;
355
356	front = __intel_frontbuffer_get(obj);
357	if (front) {
358		intel_frontbuffer_flush(front, origin);
359		intel_frontbuffer_put(front);
360	}
361}
362
363void __i915_gem_object_invalidate_frontbuffer(struct drm_i915_gem_object *obj,
364					      enum fb_op_origin origin)
365{
366	struct intel_frontbuffer *front;
367
368	front = __intel_frontbuffer_get(obj);
369	if (front) {
370		intel_frontbuffer_invalidate(front, origin);
371		intel_frontbuffer_put(front);
372	}
373}
374
375void i915_gem_init__objects(struct drm_i915_private *i915)
376{
377	INIT_WORK(&i915->mm.free_work, __i915_gem_free_work);
378}
379
380static void i915_global_objects_shrink(void)
381{
382	kmem_cache_shrink(global.slab_objects);
383}
384
385static void i915_global_objects_exit(void)
386{
387	kmem_cache_destroy(global.slab_objects);
388}
389
390static struct i915_global_object global = { {
391	.shrink = i915_global_objects_shrink,
392	.exit = i915_global_objects_exit,
393} };
394
395int __init i915_global_objects_init(void)
396{
397	global.slab_objects =
398		KMEM_CACHE(drm_i915_gem_object, SLAB_HWCACHE_ALIGN);
399	if (!global.slab_objects)
400		return -ENOMEM;
401
402	i915_global_register(&global.base);
403	return 0;
404}
405
406#if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
407#include "selftests/huge_gem_object.c"
408#include "selftests/huge_pages.c"
409#include "selftests/i915_gem_object.c"
410#include "selftests/i915_gem_coherency.c"
411#endif