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 "display/intel_frontbuffer.h"
26 #include "gt/intel_gt.h"
27 #include "i915_drv.h"
28 #include "i915_gem_clflush.h"
29 #include "i915_gem_context.h"
30 #include "i915_gem_object.h"
31 #include "i915_globals.h"
32 
33 static struct i915_global_object {
34 	struct i915_global base;
35 	struct kmem_cache *slab_objects;
36 } global;
37 
38 struct drm_i915_gem_object *i915_gem_object_alloc(void)
39 {
40 	return kmem_cache_zalloc(global.slab_objects, GFP_KERNEL);
41 }
42 
43 void i915_gem_object_free(struct drm_i915_gem_object *obj)
44 {
45 	return kmem_cache_free(global.slab_objects, obj);
46 }
47 
48 static void
49 frontbuffer_retire(struct i915_active_request *active,
50 		   struct i915_request *request)
51 {
52 	struct drm_i915_gem_object *obj =
53 		container_of(active, typeof(*obj), frontbuffer_write);
54 
55 	intel_fb_obj_flush(obj, ORIGIN_CS);
56 }
57 
58 void i915_gem_object_init(struct drm_i915_gem_object *obj,
59 			  const struct drm_i915_gem_object_ops *ops)
60 {
61 	mutex_init(&obj->mm.lock);
62 
63 	spin_lock_init(&obj->vma.lock);
64 	INIT_LIST_HEAD(&obj->vma.list);
65 
66 	INIT_LIST_HEAD(&obj->lut_list);
67 	INIT_LIST_HEAD(&obj->batch_pool_link);
68 
69 	init_rcu_head(&obj->rcu);
70 
71 	obj->ops = ops;
72 
73 	obj->frontbuffer_ggtt_origin = ORIGIN_GTT;
74 	i915_active_request_init(&obj->frontbuffer_write,
75 				 NULL, frontbuffer_retire);
76 
77 	obj->mm.madv = I915_MADV_WILLNEED;
78 	INIT_RADIX_TREE(&obj->mm.get_page.radix, GFP_KERNEL | __GFP_NOWARN);
79 	mutex_init(&obj->mm.get_page.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  */
87 void 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 
104 void 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 *lut, *ln;
109 	LIST_HEAD(close);
110 
111 	i915_gem_object_lock(obj);
112 	list_for_each_entry_safe(lut, ln, &obj->lut_list, obj_link) {
113 		struct i915_gem_context *ctx = lut->ctx;
114 
115 		if (ctx->file_priv != fpriv)
116 			continue;
117 
118 		i915_gem_context_get(ctx);
119 		list_move(&lut->obj_link, &close);
120 	}
121 	i915_gem_object_unlock(obj);
122 
123 	list_for_each_entry_safe(lut, ln, &close, obj_link) {
124 		struct i915_gem_context *ctx = lut->ctx;
125 		struct i915_vma *vma;
126 
127 		/*
128 		 * We allow the process to have multiple handles to the same
129 		 * vma, in the same fd namespace, by virtue of flink/open.
130 		 */
131 
132 		mutex_lock(&ctx->mutex);
133 		vma = radix_tree_delete(&ctx->handles_vma, lut->handle);
134 		if (vma) {
135 			GEM_BUG_ON(vma->obj != obj);
136 			GEM_BUG_ON(!atomic_read(&vma->open_count));
137 			if (atomic_dec_and_test(&vma->open_count) &&
138 			    !i915_vma_is_ggtt(vma))
139 				i915_vma_close(vma);
140 		}
141 		mutex_unlock(&ctx->mutex);
142 
143 		i915_gem_context_put(lut->ctx);
144 		i915_lut_handle_free(lut);
145 		i915_gem_object_put(obj);
146 	}
147 }
148 
149 static void __i915_gem_free_object_rcu(struct rcu_head *head)
150 {
151 	struct drm_i915_gem_object *obj =
152 		container_of(head, typeof(*obj), rcu);
153 	struct drm_i915_private *i915 = to_i915(obj->base.dev);
154 
155 	reservation_object_fini(&obj->base._resv);
156 	i915_gem_object_free(obj);
157 
158 	GEM_BUG_ON(!atomic_read(&i915->mm.free_count));
159 	atomic_dec(&i915->mm.free_count);
160 }
161 
162 static void __i915_gem_free_objects(struct drm_i915_private *i915,
163 				    struct llist_node *freed)
164 {
165 	struct drm_i915_gem_object *obj, *on;
166 	intel_wakeref_t wakeref;
167 
168 	wakeref = intel_runtime_pm_get(&i915->runtime_pm);
169 	llist_for_each_entry_safe(obj, on, freed, freed) {
170 		struct i915_vma *vma, *vn;
171 
172 		trace_i915_gem_object_destroy(obj);
173 
174 		mutex_lock(&i915->drm.struct_mutex);
175 
176 		list_for_each_entry_safe(vma, vn, &obj->vma.list, obj_link) {
177 			GEM_BUG_ON(i915_vma_is_active(vma));
178 			vma->flags &= ~I915_VMA_PIN_MASK;
179 			i915_vma_destroy(vma);
180 		}
181 		GEM_BUG_ON(!list_empty(&obj->vma.list));
182 		GEM_BUG_ON(!RB_EMPTY_ROOT(&obj->vma.tree));
183 
184 		mutex_unlock(&i915->drm.struct_mutex);
185 
186 		GEM_BUG_ON(atomic_read(&obj->bind_count));
187 		GEM_BUG_ON(obj->userfault_count);
188 		GEM_BUG_ON(atomic_read(&obj->frontbuffer_bits));
189 		GEM_BUG_ON(!list_empty(&obj->lut_list));
190 
191 		atomic_set(&obj->mm.pages_pin_count, 0);
192 		__i915_gem_object_put_pages(obj, I915_MM_NORMAL);
193 		GEM_BUG_ON(i915_gem_object_has_pages(obj));
194 		bitmap_free(obj->bit_17);
195 
196 		if (obj->base.import_attach)
197 			drm_prime_gem_destroy(&obj->base, NULL);
198 
199 		drm_gem_free_mmap_offset(&obj->base);
200 
201 		if (obj->ops->release)
202 			obj->ops->release(obj);
203 
204 		/* But keep the pointer alive for RCU-protected lookups */
205 		call_rcu(&obj->rcu, __i915_gem_free_object_rcu);
206 	}
207 	intel_runtime_pm_put(&i915->runtime_pm, wakeref);
208 }
209 
210 void i915_gem_flush_free_objects(struct drm_i915_private *i915)
211 {
212 	struct llist_node *freed;
213 
214 	/* Free the oldest, most stale object to keep the free_list short */
215 	freed = NULL;
216 	if (!llist_empty(&i915->mm.free_list)) { /* quick test for hotpath */
217 		/* Only one consumer of llist_del_first() allowed */
218 		spin_lock(&i915->mm.free_lock);
219 		freed = llist_del_first(&i915->mm.free_list);
220 		spin_unlock(&i915->mm.free_lock);
221 	}
222 	if (unlikely(freed)) {
223 		freed->next = NULL;
224 		__i915_gem_free_objects(i915, freed);
225 	}
226 }
227 
228 static void __i915_gem_free_work(struct work_struct *work)
229 {
230 	struct drm_i915_private *i915 =
231 		container_of(work, struct drm_i915_private, mm.free_work);
232 	struct llist_node *freed;
233 
234 	/*
235 	 * All file-owned VMA should have been released by this point through
236 	 * i915_gem_close_object(), or earlier by i915_gem_context_close().
237 	 * However, the object may also be bound into the global GTT (e.g.
238 	 * older GPUs without per-process support, or for direct access through
239 	 * the GTT either for the user or for scanout). Those VMA still need to
240 	 * unbound now.
241 	 */
242 
243 	spin_lock(&i915->mm.free_lock);
244 	while ((freed = llist_del_all(&i915->mm.free_list))) {
245 		spin_unlock(&i915->mm.free_lock);
246 
247 		__i915_gem_free_objects(i915, freed);
248 		if (need_resched())
249 			return;
250 
251 		spin_lock(&i915->mm.free_lock);
252 	}
253 	spin_unlock(&i915->mm.free_lock);
254 }
255 
256 void i915_gem_free_object(struct drm_gem_object *gem_obj)
257 {
258 	struct drm_i915_gem_object *obj = to_intel_bo(gem_obj);
259 	struct drm_i915_private *i915 = to_i915(obj->base.dev);
260 
261 	/*
262 	 * Before we free the object, make sure any pure RCU-only
263 	 * read-side critical sections are complete, e.g.
264 	 * i915_gem_busy_ioctl(). For the corresponding synchronized
265 	 * lookup see i915_gem_object_lookup_rcu().
266 	 */
267 	atomic_inc(&i915->mm.free_count);
268 
269 	/*
270 	 * This serializes freeing with the shrinker. Since the free
271 	 * is delayed, first by RCU then by the workqueue, we want the
272 	 * shrinker to be able to free pages of unreferenced objects,
273 	 * or else we may oom whilst there are plenty of deferred
274 	 * freed objects.
275 	 */
276 	if (i915_gem_object_has_pages(obj) &&
277 	    i915_gem_object_is_shrinkable(obj)) {
278 		unsigned long flags;
279 
280 		spin_lock_irqsave(&i915->mm.obj_lock, flags);
281 		list_del_init(&obj->mm.link);
282 		spin_unlock_irqrestore(&i915->mm.obj_lock, flags);
283 	}
284 
285 	/*
286 	 * Since we require blocking on struct_mutex to unbind the freed
287 	 * object from the GPU before releasing resources back to the
288 	 * system, we can not do that directly from the RCU callback (which may
289 	 * be a softirq context), but must instead then defer that work onto a
290 	 * kthread. We use the RCU callback rather than move the freed object
291 	 * directly onto the work queue so that we can mix between using the
292 	 * worker and performing frees directly from subsequent allocations for
293 	 * crude but effective memory throttling.
294 	 */
295 	if (llist_add(&obj->freed, &i915->mm.free_list))
296 		queue_work(i915->wq, &i915->mm.free_work);
297 }
298 
299 static inline enum fb_op_origin
300 fb_write_origin(struct drm_i915_gem_object *obj, unsigned int domain)
301 {
302 	return (domain == I915_GEM_DOMAIN_GTT ?
303 		obj->frontbuffer_ggtt_origin : ORIGIN_CPU);
304 }
305 
306 static bool gpu_write_needs_clflush(struct drm_i915_gem_object *obj)
307 {
308 	return !(obj->cache_level == I915_CACHE_NONE ||
309 		 obj->cache_level == I915_CACHE_WT);
310 }
311 
312 void
313 i915_gem_object_flush_write_domain(struct drm_i915_gem_object *obj,
314 				   unsigned int flush_domains)
315 {
316 	struct i915_vma *vma;
317 
318 	assert_object_held(obj);
319 
320 	if (!(obj->write_domain & flush_domains))
321 		return;
322 
323 	switch (obj->write_domain) {
324 	case I915_GEM_DOMAIN_GTT:
325 		for_each_ggtt_vma(vma, obj)
326 			intel_gt_flush_ggtt_writes(vma->vm->gt);
327 
328 		intel_fb_obj_flush(obj,
329 				   fb_write_origin(obj, I915_GEM_DOMAIN_GTT));
330 
331 		for_each_ggtt_vma(vma, obj) {
332 			if (vma->iomap)
333 				continue;
334 
335 			i915_vma_unset_ggtt_write(vma);
336 		}
337 
338 		break;
339 
340 	case I915_GEM_DOMAIN_WC:
341 		wmb();
342 		break;
343 
344 	case I915_GEM_DOMAIN_CPU:
345 		i915_gem_clflush_object(obj, I915_CLFLUSH_SYNC);
346 		break;
347 
348 	case I915_GEM_DOMAIN_RENDER:
349 		if (gpu_write_needs_clflush(obj))
350 			obj->cache_dirty = true;
351 		break;
352 	}
353 
354 	obj->write_domain = 0;
355 }
356 
357 void i915_gem_init__objects(struct drm_i915_private *i915)
358 {
359 	INIT_WORK(&i915->mm.free_work, __i915_gem_free_work);
360 }
361 
362 static void i915_global_objects_shrink(void)
363 {
364 	kmem_cache_shrink(global.slab_objects);
365 }
366 
367 static void i915_global_objects_exit(void)
368 {
369 	kmem_cache_destroy(global.slab_objects);
370 }
371 
372 static struct i915_global_object global = { {
373 	.shrink = i915_global_objects_shrink,
374 	.exit = i915_global_objects_exit,
375 } };
376 
377 int __init i915_global_objects_init(void)
378 {
379 	global.slab_objects =
380 		KMEM_CACHE(drm_i915_gem_object, SLAB_HWCACHE_ALIGN);
381 	if (!global.slab_objects)
382 		return -ENOMEM;
383 
384 	i915_global_register(&global.base);
385 	return 0;
386 }
387 
388 #if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
389 #include "selftests/huge_gem_object.c"
390 #include "selftests/huge_pages.c"
391 #include "selftests/i915_gem_object.c"
392 #include "selftests/i915_gem_coherency.c"
393 #endif
394