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 
37 static struct i915_global_object {
38 	struct i915_global base;
39 	struct kmem_cache *slab_objects;
40 } global;
41 
42 static const struct drm_gem_object_funcs i915_gem_object_funcs;
43 
44 struct 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 
56 void i915_gem_object_free(struct drm_i915_gem_object *obj)
57 {
58 	return kmem_cache_free(global.slab_objects, obj);
59 }
60 
61 void 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)
64 {
65 	__mutex_init(&obj->mm.lock, ops->name ?: "obj->mm.lock", key);
66 
67 	spin_lock_init(&obj->vma.lock);
68 	INIT_LIST_HEAD(&obj->vma.list);
69 
70 	INIT_LIST_HEAD(&obj->mm.link);
71 
72 	INIT_LIST_HEAD(&obj->lut_list);
73 	spin_lock_init(&obj->lut_lock);
74 
75 	spin_lock_init(&obj->mmo.lock);
76 	obj->mmo.offsets = RB_ROOT;
77 
78 	init_rcu_head(&obj->rcu);
79 
80 	obj->ops = ops;
81 
82 	obj->mm.madv = I915_MADV_WILLNEED;
83 	INIT_RADIX_TREE(&obj->mm.get_page.radix, GFP_KERNEL | __GFP_NOWARN);
84 	mutex_init(&obj->mm.get_page.lock);
85 	INIT_RADIX_TREE(&obj->mm.get_dma_page.radix, GFP_KERNEL | __GFP_NOWARN);
86 	mutex_init(&obj->mm.get_dma_page.lock);
87 
88 	if (IS_ENABLED(CONFIG_LOCKDEP) && i915_gem_object_is_shrinkable(obj))
89 		i915_gem_shrinker_taints_mutex(to_i915(obj->base.dev),
90 					       &obj->mm.lock);
91 }
92 
93 /**
94  * Mark up the object's coherency levels for a given cache_level
95  * @obj: #drm_i915_gem_object
96  * @cache_level: cache level
97  */
98 void i915_gem_object_set_cache_coherency(struct drm_i915_gem_object *obj,
99 					 unsigned int cache_level)
100 {
101 	obj->cache_level = cache_level;
102 
103 	if (cache_level != I915_CACHE_NONE)
104 		obj->cache_coherent = (I915_BO_CACHE_COHERENT_FOR_READ |
105 				       I915_BO_CACHE_COHERENT_FOR_WRITE);
106 	else if (HAS_LLC(to_i915(obj->base.dev)))
107 		obj->cache_coherent = I915_BO_CACHE_COHERENT_FOR_READ;
108 	else
109 		obj->cache_coherent = 0;
110 
111 	obj->cache_dirty =
112 		!(obj->cache_coherent & I915_BO_CACHE_COHERENT_FOR_WRITE);
113 }
114 
115 static void i915_gem_close_object(struct drm_gem_object *gem, struct drm_file *file)
116 {
117 	struct drm_i915_gem_object *obj = to_intel_bo(gem);
118 	struct drm_i915_file_private *fpriv = file->driver_priv;
119 	struct i915_lut_handle bookmark = {};
120 	struct i915_mmap_offset *mmo, *mn;
121 	struct i915_lut_handle *lut, *ln;
122 	LIST_HEAD(close);
123 
124 	spin_lock(&obj->lut_lock);
125 	list_for_each_entry_safe(lut, ln, &obj->lut_list, obj_link) {
126 		struct i915_gem_context *ctx = lut->ctx;
127 
128 		if (ctx && ctx->file_priv == fpriv) {
129 			i915_gem_context_get(ctx);
130 			list_move(&lut->obj_link, &close);
131 		}
132 
133 		/* Break long locks, and carefully continue on from this spot */
134 		if (&ln->obj_link != &obj->lut_list) {
135 			list_add_tail(&bookmark.obj_link, &ln->obj_link);
136 			if (cond_resched_lock(&obj->lut_lock))
137 				list_safe_reset_next(&bookmark, ln, obj_link);
138 			__list_del_entry(&bookmark.obj_link);
139 		}
140 	}
141 	spin_unlock(&obj->lut_lock);
142 
143 	spin_lock(&obj->mmo.lock);
144 	rbtree_postorder_for_each_entry_safe(mmo, mn, &obj->mmo.offsets, offset)
145 		drm_vma_node_revoke(&mmo->vma_node, file);
146 	spin_unlock(&obj->mmo.lock);
147 
148 	list_for_each_entry_safe(lut, ln, &close, obj_link) {
149 		struct i915_gem_context *ctx = lut->ctx;
150 		struct i915_vma *vma;
151 
152 		/*
153 		 * We allow the process to have multiple handles to the same
154 		 * vma, in the same fd namespace, by virtue of flink/open.
155 		 */
156 
157 		mutex_lock(&ctx->lut_mutex);
158 		vma = radix_tree_delete(&ctx->handles_vma, lut->handle);
159 		if (vma) {
160 			GEM_BUG_ON(vma->obj != obj);
161 			GEM_BUG_ON(!atomic_read(&vma->open_count));
162 			i915_vma_close(vma);
163 		}
164 		mutex_unlock(&ctx->lut_mutex);
165 
166 		i915_gem_context_put(lut->ctx);
167 		i915_lut_handle_free(lut);
168 		i915_gem_object_put(obj);
169 	}
170 }
171 
172 static void __i915_gem_free_object_rcu(struct rcu_head *head)
173 {
174 	struct drm_i915_gem_object *obj =
175 		container_of(head, typeof(*obj), rcu);
176 	struct drm_i915_private *i915 = to_i915(obj->base.dev);
177 
178 	dma_resv_fini(&obj->base._resv);
179 	i915_gem_object_free(obj);
180 
181 	GEM_BUG_ON(!atomic_read(&i915->mm.free_count));
182 	atomic_dec(&i915->mm.free_count);
183 }
184 
185 static void __i915_gem_object_free_mmaps(struct drm_i915_gem_object *obj)
186 {
187 	/* Skip serialisation and waking the device if known to be not used. */
188 
189 	if (obj->userfault_count)
190 		i915_gem_object_release_mmap_gtt(obj);
191 
192 	if (!RB_EMPTY_ROOT(&obj->mmo.offsets)) {
193 		struct i915_mmap_offset *mmo, *mn;
194 
195 		i915_gem_object_release_mmap_offset(obj);
196 
197 		rbtree_postorder_for_each_entry_safe(mmo, mn,
198 						     &obj->mmo.offsets,
199 						     offset) {
200 			drm_vma_offset_remove(obj->base.dev->vma_offset_manager,
201 					      &mmo->vma_node);
202 			kfree(mmo);
203 		}
204 		obj->mmo.offsets = RB_ROOT;
205 	}
206 }
207 
208 static void __i915_gem_free_objects(struct drm_i915_private *i915,
209 				    struct llist_node *freed)
210 {
211 	struct drm_i915_gem_object *obj, *on;
212 
213 	llist_for_each_entry_safe(obj, on, freed, freed) {
214 		trace_i915_gem_object_destroy(obj);
215 
216 		if (!list_empty(&obj->vma.list)) {
217 			struct i915_vma *vma;
218 
219 			/*
220 			 * Note that the vma keeps an object reference while
221 			 * it is active, so it *should* not sleep while we
222 			 * destroy it. Our debug code errs insits it *might*.
223 			 * For the moment, play along.
224 			 */
225 			spin_lock(&obj->vma.lock);
226 			while ((vma = list_first_entry_or_null(&obj->vma.list,
227 							       struct i915_vma,
228 							       obj_link))) {
229 				GEM_BUG_ON(vma->obj != obj);
230 				spin_unlock(&obj->vma.lock);
231 
232 				__i915_vma_put(vma);
233 
234 				spin_lock(&obj->vma.lock);
235 			}
236 			spin_unlock(&obj->vma.lock);
237 		}
238 
239 		__i915_gem_object_free_mmaps(obj);
240 
241 		GEM_BUG_ON(!list_empty(&obj->lut_list));
242 
243 		atomic_set(&obj->mm.pages_pin_count, 0);
244 		__i915_gem_object_put_pages(obj);
245 		GEM_BUG_ON(i915_gem_object_has_pages(obj));
246 		bitmap_free(obj->bit_17);
247 
248 		if (obj->base.import_attach)
249 			drm_prime_gem_destroy(&obj->base, NULL);
250 
251 		drm_gem_free_mmap_offset(&obj->base);
252 
253 		if (obj->ops->release)
254 			obj->ops->release(obj);
255 
256 		/* But keep the pointer alive for RCU-protected lookups */
257 		call_rcu(&obj->rcu, __i915_gem_free_object_rcu);
258 		cond_resched();
259 	}
260 }
261 
262 void i915_gem_flush_free_objects(struct drm_i915_private *i915)
263 {
264 	struct llist_node *freed = llist_del_all(&i915->mm.free_list);
265 
266 	if (unlikely(freed))
267 		__i915_gem_free_objects(i915, freed);
268 }
269 
270 static void __i915_gem_free_work(struct work_struct *work)
271 {
272 	struct drm_i915_private *i915 =
273 		container_of(work, struct drm_i915_private, mm.free_work);
274 
275 	i915_gem_flush_free_objects(i915);
276 }
277 
278 static void i915_gem_free_object(struct drm_gem_object *gem_obj)
279 {
280 	struct drm_i915_gem_object *obj = to_intel_bo(gem_obj);
281 	struct drm_i915_private *i915 = to_i915(obj->base.dev);
282 
283 	GEM_BUG_ON(i915_gem_object_is_framebuffer(obj));
284 
285 	/*
286 	 * Before we free the object, make sure any pure RCU-only
287 	 * read-side critical sections are complete, e.g.
288 	 * i915_gem_busy_ioctl(). For the corresponding synchronized
289 	 * lookup see i915_gem_object_lookup_rcu().
290 	 */
291 	atomic_inc(&i915->mm.free_count);
292 
293 	/*
294 	 * This serializes freeing with the shrinker. Since the free
295 	 * is delayed, first by RCU then by the workqueue, we want the
296 	 * shrinker to be able to free pages of unreferenced objects,
297 	 * or else we may oom whilst there are plenty of deferred
298 	 * freed objects.
299 	 */
300 	i915_gem_object_make_unshrinkable(obj);
301 
302 	/*
303 	 * Since we require blocking on struct_mutex to unbind the freed
304 	 * object from the GPU before releasing resources back to the
305 	 * system, we can not do that directly from the RCU callback (which may
306 	 * be a softirq context), but must instead then defer that work onto a
307 	 * kthread. We use the RCU callback rather than move the freed object
308 	 * directly onto the work queue so that we can mix between using the
309 	 * worker and performing frees directly from subsequent allocations for
310 	 * crude but effective memory throttling.
311 	 */
312 	if (llist_add(&obj->freed, &i915->mm.free_list))
313 		queue_work(i915->wq, &i915->mm.free_work);
314 }
315 
316 void __i915_gem_object_flush_frontbuffer(struct drm_i915_gem_object *obj,
317 					 enum fb_op_origin origin)
318 {
319 	struct intel_frontbuffer *front;
320 
321 	front = __intel_frontbuffer_get(obj);
322 	if (front) {
323 		intel_frontbuffer_flush(front, origin);
324 		intel_frontbuffer_put(front);
325 	}
326 }
327 
328 void __i915_gem_object_invalidate_frontbuffer(struct drm_i915_gem_object *obj,
329 					      enum fb_op_origin origin)
330 {
331 	struct intel_frontbuffer *front;
332 
333 	front = __intel_frontbuffer_get(obj);
334 	if (front) {
335 		intel_frontbuffer_invalidate(front, origin);
336 		intel_frontbuffer_put(front);
337 	}
338 }
339 
340 static void
341 i915_gem_object_read_from_page_kmap(struct drm_i915_gem_object *obj, u64 offset, void *dst, int size)
342 {
343 	void *src_map;
344 	void *src_ptr;
345 
346 	src_map = kmap_atomic(i915_gem_object_get_page(obj, offset >> PAGE_SHIFT));
347 
348 	src_ptr = src_map + offset_in_page(offset);
349 	if (!(obj->cache_coherent & I915_BO_CACHE_COHERENT_FOR_READ))
350 		drm_clflush_virt_range(src_ptr, size);
351 	memcpy(dst, src_ptr, size);
352 
353 	kunmap_atomic(src_map);
354 }
355 
356 static void
357 i915_gem_object_read_from_page_iomap(struct drm_i915_gem_object *obj, u64 offset, void *dst, int size)
358 {
359 	void __iomem *src_map;
360 	void __iomem *src_ptr;
361 	dma_addr_t dma = i915_gem_object_get_dma_address(obj, offset >> PAGE_SHIFT);
362 
363 	src_map = io_mapping_map_wc(&obj->mm.region->iomap,
364 				    dma - obj->mm.region->region.start,
365 				    PAGE_SIZE);
366 
367 	src_ptr = src_map + offset_in_page(offset);
368 	if (!i915_memcpy_from_wc(dst, (void __force *)src_ptr, size))
369 		memcpy_fromio(dst, src_ptr, size);
370 
371 	io_mapping_unmap(src_map);
372 }
373 
374 /**
375  * i915_gem_object_read_from_page - read data from the page of a GEM object
376  * @obj: GEM object to read from
377  * @offset: offset within the object
378  * @dst: buffer to store the read data
379  * @size: size to read
380  *
381  * Reads data from @obj at the specified offset. The requested region to read
382  * from can't cross a page boundary. The caller must ensure that @obj pages
383  * are pinned and that @obj is synced wrt. any related writes.
384  *
385  * Returns 0 on success or -ENODEV if the type of @obj's backing store is
386  * unsupported.
387  */
388 int i915_gem_object_read_from_page(struct drm_i915_gem_object *obj, u64 offset, void *dst, int size)
389 {
390 	GEM_BUG_ON(offset >= obj->base.size);
391 	GEM_BUG_ON(offset_in_page(offset) > PAGE_SIZE - size);
392 	GEM_BUG_ON(!i915_gem_object_has_pinned_pages(obj));
393 
394 	if (i915_gem_object_has_struct_page(obj))
395 		i915_gem_object_read_from_page_kmap(obj, offset, dst, size);
396 	else if (i915_gem_object_has_iomem(obj))
397 		i915_gem_object_read_from_page_iomap(obj, offset, dst, size);
398 	else
399 		return -ENODEV;
400 
401 	return 0;
402 }
403 
404 void i915_gem_init__objects(struct drm_i915_private *i915)
405 {
406 	INIT_WORK(&i915->mm.free_work, __i915_gem_free_work);
407 }
408 
409 static void i915_global_objects_shrink(void)
410 {
411 	kmem_cache_shrink(global.slab_objects);
412 }
413 
414 static void i915_global_objects_exit(void)
415 {
416 	kmem_cache_destroy(global.slab_objects);
417 }
418 
419 static struct i915_global_object global = { {
420 	.shrink = i915_global_objects_shrink,
421 	.exit = i915_global_objects_exit,
422 } };
423 
424 int __init i915_global_objects_init(void)
425 {
426 	global.slab_objects =
427 		KMEM_CACHE(drm_i915_gem_object, SLAB_HWCACHE_ALIGN);
428 	if (!global.slab_objects)
429 		return -ENOMEM;
430 
431 	i915_global_register(&global.base);
432 	return 0;
433 }
434 
435 static const struct drm_gem_object_funcs i915_gem_object_funcs = {
436 	.free = i915_gem_free_object,
437 	.close = i915_gem_close_object,
438 	.export = i915_gem_prime_export,
439 };
440 
441 #if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
442 #include "selftests/huge_gem_object.c"
443 #include "selftests/huge_pages.c"
444 #include "selftests/i915_gem_object.c"
445 #include "selftests/i915_gem_coherency.c"
446 #endif
447