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 "i915_drv.h"
 29#include "i915_gem_clflush.h"
 30#include "i915_gem_context.h"
 31#include "i915_gem_mman.h"
 32#include "i915_gem_object.h"
 33#include "i915_globals.h"
 34#include "i915_memcpy.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
 42static const struct drm_gem_object_funcs i915_gem_object_funcs;
 43
 44struct drm_i915_gem_object *i915_gem_object_alloc(void)
 45{
 46	struct drm_i915_gem_object *obj;
 47
 48	obj = kmem_cache_zalloc(global.slab_objects, GFP_KERNEL);
 49	if (!obj)
 50		return NULL;
 51	obj->base.funcs = &i915_gem_object_funcs;
 52
 53	return obj;
 54}
 55
 56void i915_gem_object_free(struct drm_i915_gem_object *obj)
 57{
 58	return kmem_cache_free(global.slab_objects, obj);
 59}
 60
 61void i915_gem_object_init(struct drm_i915_gem_object *obj,
 62			  const struct drm_i915_gem_object_ops *ops,
 63			  struct lock_class_key *key, unsigned flags)
 64{
 65	/*
 66	 * A gem object is embedded both in a struct ttm_buffer_object :/ and
 67	 * in a drm_i915_gem_object. Make sure they are aliased.
 68	 */
 69	BUILD_BUG_ON(offsetof(typeof(*obj), base) !=
 70		     offsetof(typeof(*obj), __do_not_access.base));
 71
 72	spin_lock_init(&obj->vma.lock);
 73	INIT_LIST_HEAD(&obj->vma.list);
 74
 75	INIT_LIST_HEAD(&obj->mm.link);
 76
 77	INIT_LIST_HEAD(&obj->lut_list);
 78	spin_lock_init(&obj->lut_lock);
 79
 80	spin_lock_init(&obj->mmo.lock);
 81	obj->mmo.offsets = RB_ROOT;
 82
 83	init_rcu_head(&obj->rcu);
 84
 85	obj->ops = ops;
 86	GEM_BUG_ON(flags & ~I915_BO_ALLOC_FLAGS);
 87	obj->flags = flags;
 88
 89	obj->mm.madv = I915_MADV_WILLNEED;
 90	INIT_RADIX_TREE(&obj->mm.get_page.radix, GFP_KERNEL | __GFP_NOWARN);
 91	mutex_init(&obj->mm.get_page.lock);
 92	INIT_RADIX_TREE(&obj->mm.get_dma_page.radix, GFP_KERNEL | __GFP_NOWARN);
 93	mutex_init(&obj->mm.get_dma_page.lock);
 94}
 95
 96/**
 97 * Mark up the object's coherency levels for a given cache_level
 98 * @obj: #drm_i915_gem_object
 99 * @cache_level: cache level
100 */
101void i915_gem_object_set_cache_coherency(struct drm_i915_gem_object *obj,
102					 unsigned int cache_level)
103{
104	obj->cache_level = cache_level;
105
106	if (cache_level != I915_CACHE_NONE)
107		obj->cache_coherent = (I915_BO_CACHE_COHERENT_FOR_READ |
108				       I915_BO_CACHE_COHERENT_FOR_WRITE);
109	else if (HAS_LLC(to_i915(obj->base.dev)))
110		obj->cache_coherent = I915_BO_CACHE_COHERENT_FOR_READ;
111	else
112		obj->cache_coherent = 0;
113
114	obj->cache_dirty =
115		!(obj->cache_coherent & I915_BO_CACHE_COHERENT_FOR_WRITE);
116}
117
118static void i915_gem_close_object(struct drm_gem_object *gem, struct drm_file *file)
119{
120	struct drm_i915_gem_object *obj = to_intel_bo(gem);
121	struct drm_i915_file_private *fpriv = file->driver_priv;
122	struct i915_lut_handle bookmark = {};
123	struct i915_mmap_offset *mmo, *mn;
124	struct i915_lut_handle *lut, *ln;
125	LIST_HEAD(close);
126
127	spin_lock(&obj->lut_lock);
128	list_for_each_entry_safe(lut, ln, &obj->lut_list, obj_link) {
129		struct i915_gem_context *ctx = lut->ctx;
130
131		if (ctx && ctx->file_priv == fpriv) {
132			i915_gem_context_get(ctx);
133			list_move(&lut->obj_link, &close);
134		}
135
136		/* Break long locks, and carefully continue on from this spot */
137		if (&ln->obj_link != &obj->lut_list) {
138			list_add_tail(&bookmark.obj_link, &ln->obj_link);
139			if (cond_resched_lock(&obj->lut_lock))
140				list_safe_reset_next(&bookmark, ln, obj_link);
141			__list_del_entry(&bookmark.obj_link);
142		}
143	}
144	spin_unlock(&obj->lut_lock);
145
146	spin_lock(&obj->mmo.lock);
147	rbtree_postorder_for_each_entry_safe(mmo, mn, &obj->mmo.offsets, offset)
148		drm_vma_node_revoke(&mmo->vma_node, file);
149	spin_unlock(&obj->mmo.lock);
150
151	list_for_each_entry_safe(lut, ln, &close, obj_link) {
152		struct i915_gem_context *ctx = lut->ctx;
153		struct i915_vma *vma;
154
155		/*
156		 * We allow the process to have multiple handles to the same
157		 * vma, in the same fd namespace, by virtue of flink/open.
158		 */
159
160		mutex_lock(&ctx->lut_mutex);
161		vma = radix_tree_delete(&ctx->handles_vma, lut->handle);
162		if (vma) {
163			GEM_BUG_ON(vma->obj != obj);
164			GEM_BUG_ON(!atomic_read(&vma->open_count));
165			i915_vma_close(vma);
166		}
167		mutex_unlock(&ctx->lut_mutex);
168
169		i915_gem_context_put(lut->ctx);
170		i915_lut_handle_free(lut);
171		i915_gem_object_put(obj);
172	}
173}
174
175static void __i915_gem_free_object_rcu(struct rcu_head *head)
176{
177	struct drm_i915_gem_object *obj =
178		container_of(head, typeof(*obj), rcu);
179	struct drm_i915_private *i915 = to_i915(obj->base.dev);
180
181	dma_resv_fini(&obj->base._resv);
182	i915_gem_object_free(obj);
183
184	GEM_BUG_ON(!atomic_read(&i915->mm.free_count));
185	atomic_dec(&i915->mm.free_count);
186}
187
188static void __i915_gem_object_free_mmaps(struct drm_i915_gem_object *obj)
189{
190	/* Skip serialisation and waking the device if known to be not used. */
191
192	if (obj->userfault_count)
193		i915_gem_object_release_mmap_gtt(obj);
194
195	if (!RB_EMPTY_ROOT(&obj->mmo.offsets)) {
196		struct i915_mmap_offset *mmo, *mn;
197
198		i915_gem_object_release_mmap_offset(obj);
199
200		rbtree_postorder_for_each_entry_safe(mmo, mn,
201						     &obj->mmo.offsets,
202						     offset) {
203			drm_vma_offset_remove(obj->base.dev->vma_offset_manager,
204					      &mmo->vma_node);
205			kfree(mmo);
206		}
207		obj->mmo.offsets = RB_ROOT;
208	}
209}
210
211static void __i915_gem_free_objects(struct drm_i915_private *i915,
212				    struct llist_node *freed)
213{
214	struct drm_i915_gem_object *obj, *on;
215
216	llist_for_each_entry_safe(obj, on, freed, freed) {
217		trace_i915_gem_object_destroy(obj);
218
219		if (!list_empty(&obj->vma.list)) {
220			struct i915_vma *vma;
221
222			/*
223			 * Note that the vma keeps an object reference while
224			 * it is active, so it *should* not sleep while we
225			 * destroy it. Our debug code errs insits it *might*.
226			 * For the moment, play along.
227			 */
228			spin_lock(&obj->vma.lock);
229			while ((vma = list_first_entry_or_null(&obj->vma.list,
230							       struct i915_vma,
231							       obj_link))) {
232				GEM_BUG_ON(vma->obj != obj);
233				spin_unlock(&obj->vma.lock);
234
235				__i915_vma_put(vma);
236
237				spin_lock(&obj->vma.lock);
238			}
239			spin_unlock(&obj->vma.lock);
240		}
241
242		__i915_gem_object_free_mmaps(obj);
243
244		GEM_BUG_ON(!list_empty(&obj->lut_list));
245
246		atomic_set(&obj->mm.pages_pin_count, 0);
247		__i915_gem_object_put_pages(obj);
248		GEM_BUG_ON(i915_gem_object_has_pages(obj));
249		bitmap_free(obj->bit_17);
250
251		if (obj->base.import_attach)
252			drm_prime_gem_destroy(&obj->base, NULL);
253
254		drm_gem_free_mmap_offset(&obj->base);
255
256		if (obj->ops->release)
257			obj->ops->release(obj);
258
259		if (obj->mm.n_placements > 1)
260			kfree(obj->mm.placements);
261
262		if (obj->shares_resv_from)
263			i915_vm_resv_put(obj->shares_resv_from);
264
265		/* But keep the pointer alive for RCU-protected lookups */
266		call_rcu(&obj->rcu, __i915_gem_free_object_rcu);
267		cond_resched();
268	}
269}
270
271void i915_gem_flush_free_objects(struct drm_i915_private *i915)
272{
273	struct llist_node *freed = llist_del_all(&i915->mm.free_list);
274
275	if (unlikely(freed))
276		__i915_gem_free_objects(i915, freed);
277}
278
279static void __i915_gem_free_work(struct work_struct *work)
280{
281	struct drm_i915_private *i915 =
282		container_of(work, struct drm_i915_private, mm.free_work);
283
284	i915_gem_flush_free_objects(i915);
285}
286
287static void i915_gem_free_object(struct drm_gem_object *gem_obj)
288{
289	struct drm_i915_gem_object *obj = to_intel_bo(gem_obj);
290	struct drm_i915_private *i915 = to_i915(obj->base.dev);
291
292	GEM_BUG_ON(i915_gem_object_is_framebuffer(obj));
293
294	/*
295	 * Before we free the object, make sure any pure RCU-only
296	 * read-side critical sections are complete, e.g.
297	 * i915_gem_busy_ioctl(). For the corresponding synchronized
298	 * lookup see i915_gem_object_lookup_rcu().
299	 */
300	atomic_inc(&i915->mm.free_count);
301
302	/*
303	 * This serializes freeing with the shrinker. Since the free
304	 * is delayed, first by RCU then by the workqueue, we want the
305	 * shrinker to be able to free pages of unreferenced objects,
306	 * or else we may oom whilst there are plenty of deferred
307	 * freed objects.
308	 */
309	i915_gem_object_make_unshrinkable(obj);
310
311	/*
312	 * Since we require blocking on struct_mutex to unbind the freed
313	 * object from the GPU before releasing resources back to the
314	 * system, we can not do that directly from the RCU callback (which may
315	 * be a softirq context), but must instead then defer that work onto a
316	 * kthread. We use the RCU callback rather than move the freed object
317	 * directly onto the work queue so that we can mix between using the
318	 * worker and performing frees directly from subsequent allocations for
319	 * crude but effective memory throttling.
320	 */
321	if (llist_add(&obj->freed, &i915->mm.free_list))
322		queue_work(i915->wq, &i915->mm.free_work);
323}
324
325void __i915_gem_object_flush_frontbuffer(struct drm_i915_gem_object *obj,
326					 enum fb_op_origin origin)
327{
328	struct intel_frontbuffer *front;
329
330	front = __intel_frontbuffer_get(obj);
331	if (front) {
332		intel_frontbuffer_flush(front, origin);
333		intel_frontbuffer_put(front);
334	}
335}
336
337void __i915_gem_object_invalidate_frontbuffer(struct drm_i915_gem_object *obj,
338					      enum fb_op_origin origin)
339{
340	struct intel_frontbuffer *front;
341
342	front = __intel_frontbuffer_get(obj);
343	if (front) {
344		intel_frontbuffer_invalidate(front, origin);
345		intel_frontbuffer_put(front);
346	}
347}
348
349static void
350i915_gem_object_read_from_page_kmap(struct drm_i915_gem_object *obj, u64 offset, void *dst, int size)
351{
352	void *src_map;
353	void *src_ptr;
354
355	src_map = kmap_atomic(i915_gem_object_get_page(obj, offset >> PAGE_SHIFT));
356
357	src_ptr = src_map + offset_in_page(offset);
358	if (!(obj->cache_coherent & I915_BO_CACHE_COHERENT_FOR_READ))
359		drm_clflush_virt_range(src_ptr, size);
360	memcpy(dst, src_ptr, size);
361
362	kunmap_atomic(src_map);
363}
364
365static void
366i915_gem_object_read_from_page_iomap(struct drm_i915_gem_object *obj, u64 offset, void *dst, int size)
367{
368	void __iomem *src_map;
369	void __iomem *src_ptr;
370	dma_addr_t dma = i915_gem_object_get_dma_address(obj, offset >> PAGE_SHIFT);
371
372	src_map = io_mapping_map_wc(&obj->mm.region->iomap,
373				    dma - obj->mm.region->region.start,
374				    PAGE_SIZE);
375
376	src_ptr = src_map + offset_in_page(offset);
377	if (!i915_memcpy_from_wc(dst, (void __force *)src_ptr, size))
378		memcpy_fromio(dst, src_ptr, size);
379
380	io_mapping_unmap(src_map);
381}
382
383/**
384 * i915_gem_object_read_from_page - read data from the page of a GEM object
385 * @obj: GEM object to read from
386 * @offset: offset within the object
387 * @dst: buffer to store the read data
388 * @size: size to read
389 *
390 * Reads data from @obj at the specified offset. The requested region to read
391 * from can't cross a page boundary. The caller must ensure that @obj pages
392 * are pinned and that @obj is synced wrt. any related writes.
393 *
394 * Returns 0 on success or -ENODEV if the type of @obj's backing store is
395 * unsupported.
396 */
397int i915_gem_object_read_from_page(struct drm_i915_gem_object *obj, u64 offset, void *dst, int size)
398{
399	GEM_BUG_ON(offset >= obj->base.size);
400	GEM_BUG_ON(offset_in_page(offset) > PAGE_SIZE - size);
401	GEM_BUG_ON(!i915_gem_object_has_pinned_pages(obj));
402
403	if (i915_gem_object_has_struct_page(obj))
404		i915_gem_object_read_from_page_kmap(obj, offset, dst, size);
405	else if (i915_gem_object_has_iomem(obj))
406		i915_gem_object_read_from_page_iomap(obj, offset, dst, size);
407	else
408		return -ENODEV;
409
410	return 0;
411}
412
413void i915_gem_init__objects(struct drm_i915_private *i915)
414{
415	INIT_WORK(&i915->mm.free_work, __i915_gem_free_work);
416}
417
418static void i915_global_objects_shrink(void)
419{
420	kmem_cache_shrink(global.slab_objects);
421}
422
423static void i915_global_objects_exit(void)
424{
425	kmem_cache_destroy(global.slab_objects);
426}
427
428static struct i915_global_object global = { {
429	.shrink = i915_global_objects_shrink,
430	.exit = i915_global_objects_exit,
431} };
432
433int __init i915_global_objects_init(void)
434{
435	global.slab_objects =
436		KMEM_CACHE(drm_i915_gem_object, SLAB_HWCACHE_ALIGN);
437	if (!global.slab_objects)
438		return -ENOMEM;
439
440	i915_global_register(&global.base);
441	return 0;
442}
443
444static const struct drm_gem_object_funcs i915_gem_object_funcs = {
445	.free = i915_gem_free_object,
446	.close = i915_gem_close_object,
447	.export = i915_gem_prime_export,
448};
449
450#if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
451#include "selftests/huge_gem_object.c"
452#include "selftests/huge_pages.c"
453#include "selftests/i915_gem_object.c"
454#include "selftests/i915_gem_coherency.c"
455#endif