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 #include "i915_trace.h"
33 
34 static struct i915_global_object {
35 	struct i915_global base;
36 	struct kmem_cache *slab_objects;
37 } global;
38 
39 struct drm_i915_gem_object *i915_gem_object_alloc(void)
40 {
41 	return kmem_cache_zalloc(global.slab_objects, GFP_KERNEL);
42 }
43 
44 void i915_gem_object_free(struct drm_i915_gem_object *obj)
45 {
46 	return kmem_cache_free(global.slab_objects, obj);
47 }
48 
49 void i915_gem_object_init(struct drm_i915_gem_object *obj,
50 			  const struct drm_i915_gem_object_ops *ops)
51 {
52 	mutex_init(&obj->mm.lock);
53 
54 	spin_lock_init(&obj->vma.lock);
55 	INIT_LIST_HEAD(&obj->vma.list);
56 
57 	INIT_LIST_HEAD(&obj->mm.link);
58 
59 	INIT_LIST_HEAD(&obj->lut_list);
60 
61 	init_rcu_head(&obj->rcu);
62 
63 	obj->ops = ops;
64 
65 	obj->mm.madv = I915_MADV_WILLNEED;
66 	INIT_RADIX_TREE(&obj->mm.get_page.radix, GFP_KERNEL | __GFP_NOWARN);
67 	mutex_init(&obj->mm.get_page.lock);
68 }
69 
70 /**
71  * Mark up the object's coherency levels for a given cache_level
72  * @obj: #drm_i915_gem_object
73  * @cache_level: cache level
74  */
75 void i915_gem_object_set_cache_coherency(struct drm_i915_gem_object *obj,
76 					 unsigned int cache_level)
77 {
78 	obj->cache_level = cache_level;
79 
80 	if (cache_level != I915_CACHE_NONE)
81 		obj->cache_coherent = (I915_BO_CACHE_COHERENT_FOR_READ |
82 				       I915_BO_CACHE_COHERENT_FOR_WRITE);
83 	else if (HAS_LLC(to_i915(obj->base.dev)))
84 		obj->cache_coherent = I915_BO_CACHE_COHERENT_FOR_READ;
85 	else
86 		obj->cache_coherent = 0;
87 
88 	obj->cache_dirty =
89 		!(obj->cache_coherent & I915_BO_CACHE_COHERENT_FOR_WRITE);
90 }
91 
92 void i915_gem_close_object(struct drm_gem_object *gem, struct drm_file *file)
93 {
94 	struct drm_i915_gem_object *obj = to_intel_bo(gem);
95 	struct drm_i915_file_private *fpriv = file->driver_priv;
96 	struct i915_lut_handle *lut, *ln;
97 	LIST_HEAD(close);
98 
99 	i915_gem_object_lock(obj);
100 	list_for_each_entry_safe(lut, ln, &obj->lut_list, obj_link) {
101 		struct i915_gem_context *ctx = lut->ctx;
102 
103 		if (ctx->file_priv != fpriv)
104 			continue;
105 
106 		i915_gem_context_get(ctx);
107 		list_move(&lut->obj_link, &close);
108 	}
109 	i915_gem_object_unlock(obj);
110 
111 	list_for_each_entry_safe(lut, ln, &close, obj_link) {
112 		struct i915_gem_context *ctx = lut->ctx;
113 		struct i915_vma *vma;
114 
115 		/*
116 		 * We allow the process to have multiple handles to the same
117 		 * vma, in the same fd namespace, by virtue of flink/open.
118 		 */
119 
120 		mutex_lock(&ctx->mutex);
121 		vma = radix_tree_delete(&ctx->handles_vma, lut->handle);
122 		if (vma) {
123 			GEM_BUG_ON(vma->obj != obj);
124 			GEM_BUG_ON(!atomic_read(&vma->open_count));
125 			if (atomic_dec_and_test(&vma->open_count) &&
126 			    !i915_vma_is_ggtt(vma))
127 				i915_vma_close(vma);
128 		}
129 		mutex_unlock(&ctx->mutex);
130 
131 		i915_gem_context_put(lut->ctx);
132 		i915_lut_handle_free(lut);
133 		i915_gem_object_put(obj);
134 	}
135 }
136 
137 static void __i915_gem_free_object_rcu(struct rcu_head *head)
138 {
139 	struct drm_i915_gem_object *obj =
140 		container_of(head, typeof(*obj), rcu);
141 	struct drm_i915_private *i915 = to_i915(obj->base.dev);
142 
143 	dma_resv_fini(&obj->base._resv);
144 	i915_gem_object_free(obj);
145 
146 	GEM_BUG_ON(!atomic_read(&i915->mm.free_count));
147 	atomic_dec(&i915->mm.free_count);
148 }
149 
150 static void __i915_gem_free_objects(struct drm_i915_private *i915,
151 				    struct llist_node *freed)
152 {
153 	struct drm_i915_gem_object *obj, *on;
154 	intel_wakeref_t wakeref;
155 
156 	wakeref = intel_runtime_pm_get(&i915->runtime_pm);
157 	llist_for_each_entry_safe(obj, on, freed, freed) {
158 		trace_i915_gem_object_destroy(obj);
159 
160 		if (!list_empty(&obj->vma.list)) {
161 			struct i915_vma *vma;
162 
163 			/*
164 			 * Note that the vma keeps an object reference while
165 			 * it is active, so it *should* not sleep while we
166 			 * destroy it. Our debug code errs insits it *might*.
167 			 * For the moment, play along.
168 			 */
169 			spin_lock(&obj->vma.lock);
170 			while ((vma = list_first_entry_or_null(&obj->vma.list,
171 							       struct i915_vma,
172 							       obj_link))) {
173 				GEM_BUG_ON(vma->obj != obj);
174 				spin_unlock(&obj->vma.lock);
175 
176 				i915_vma_destroy(vma);
177 
178 				spin_lock(&obj->vma.lock);
179 			}
180 			spin_unlock(&obj->vma.lock);
181 		}
182 
183 		GEM_BUG_ON(atomic_read(&obj->bind_count));
184 		GEM_BUG_ON(obj->userfault_count);
185 		GEM_BUG_ON(!list_empty(&obj->lut_list));
186 
187 		atomic_set(&obj->mm.pages_pin_count, 0);
188 		__i915_gem_object_put_pages(obj, I915_MM_NORMAL);
189 		GEM_BUG_ON(i915_gem_object_has_pages(obj));
190 		bitmap_free(obj->bit_17);
191 
192 		if (obj->base.import_attach)
193 			drm_prime_gem_destroy(&obj->base, NULL);
194 
195 		drm_gem_free_mmap_offset(&obj->base);
196 
197 		if (obj->ops->release)
198 			obj->ops->release(obj);
199 
200 		/* But keep the pointer alive for RCU-protected lookups */
201 		call_rcu(&obj->rcu, __i915_gem_free_object_rcu);
202 	}
203 	intel_runtime_pm_put(&i915->runtime_pm, wakeref);
204 }
205 
206 void i915_gem_flush_free_objects(struct drm_i915_private *i915)
207 {
208 	struct llist_node *freed = llist_del_all(&i915->mm.free_list);
209 
210 	if (unlikely(freed))
211 		__i915_gem_free_objects(i915, freed);
212 }
213 
214 static void __i915_gem_free_work(struct work_struct *work)
215 {
216 	struct drm_i915_private *i915 =
217 		container_of(work, struct drm_i915_private, mm.free_work);
218 
219 	i915_gem_flush_free_objects(i915);
220 }
221 
222 void i915_gem_free_object(struct drm_gem_object *gem_obj)
223 {
224 	struct drm_i915_gem_object *obj = to_intel_bo(gem_obj);
225 	struct drm_i915_private *i915 = to_i915(obj->base.dev);
226 
227 	GEM_BUG_ON(i915_gem_object_is_framebuffer(obj));
228 
229 	/*
230 	 * Before we free the object, make sure any pure RCU-only
231 	 * read-side critical sections are complete, e.g.
232 	 * i915_gem_busy_ioctl(). For the corresponding synchronized
233 	 * lookup see i915_gem_object_lookup_rcu().
234 	 */
235 	atomic_inc(&i915->mm.free_count);
236 
237 	/*
238 	 * This serializes freeing with the shrinker. Since the free
239 	 * is delayed, first by RCU then by the workqueue, we want the
240 	 * shrinker to be able to free pages of unreferenced objects,
241 	 * or else we may oom whilst there are plenty of deferred
242 	 * freed objects.
243 	 */
244 	i915_gem_object_make_unshrinkable(obj);
245 
246 	/*
247 	 * Since we require blocking on struct_mutex to unbind the freed
248 	 * object from the GPU before releasing resources back to the
249 	 * system, we can not do that directly from the RCU callback (which may
250 	 * be a softirq context), but must instead then defer that work onto a
251 	 * kthread. We use the RCU callback rather than move the freed object
252 	 * directly onto the work queue so that we can mix between using the
253 	 * worker and performing frees directly from subsequent allocations for
254 	 * crude but effective memory throttling.
255 	 */
256 	if (llist_add(&obj->freed, &i915->mm.free_list))
257 		queue_work(i915->wq, &i915->mm.free_work);
258 }
259 
260 static bool gpu_write_needs_clflush(struct drm_i915_gem_object *obj)
261 {
262 	return !(obj->cache_level == I915_CACHE_NONE ||
263 		 obj->cache_level == I915_CACHE_WT);
264 }
265 
266 void
267 i915_gem_object_flush_write_domain(struct drm_i915_gem_object *obj,
268 				   unsigned int flush_domains)
269 {
270 	struct i915_vma *vma;
271 
272 	assert_object_held(obj);
273 
274 	if (!(obj->write_domain & flush_domains))
275 		return;
276 
277 	switch (obj->write_domain) {
278 	case I915_GEM_DOMAIN_GTT:
279 		for_each_ggtt_vma(vma, obj)
280 			intel_gt_flush_ggtt_writes(vma->vm->gt);
281 
282 		intel_frontbuffer_flush(obj->frontbuffer, ORIGIN_CPU);
283 
284 		for_each_ggtt_vma(vma, obj) {
285 			if (vma->iomap)
286 				continue;
287 
288 			i915_vma_unset_ggtt_write(vma);
289 		}
290 
291 		break;
292 
293 	case I915_GEM_DOMAIN_WC:
294 		wmb();
295 		break;
296 
297 	case I915_GEM_DOMAIN_CPU:
298 		i915_gem_clflush_object(obj, I915_CLFLUSH_SYNC);
299 		break;
300 
301 	case I915_GEM_DOMAIN_RENDER:
302 		if (gpu_write_needs_clflush(obj))
303 			obj->cache_dirty = true;
304 		break;
305 	}
306 
307 	obj->write_domain = 0;
308 }
309 
310 void i915_gem_init__objects(struct drm_i915_private *i915)
311 {
312 	INIT_WORK(&i915->mm.free_work, __i915_gem_free_work);
313 }
314 
315 static void i915_global_objects_shrink(void)
316 {
317 	kmem_cache_shrink(global.slab_objects);
318 }
319 
320 static void i915_global_objects_exit(void)
321 {
322 	kmem_cache_destroy(global.slab_objects);
323 }
324 
325 static struct i915_global_object global = { {
326 	.shrink = i915_global_objects_shrink,
327 	.exit = i915_global_objects_exit,
328 } };
329 
330 int __init i915_global_objects_init(void)
331 {
332 	global.slab_objects =
333 		KMEM_CACHE(drm_i915_gem_object, SLAB_HWCACHE_ALIGN);
334 	if (!global.slab_objects)
335 		return -ENOMEM;
336 
337 	i915_global_register(&global.base);
338 	return 0;
339 }
340 
341 #if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
342 #include "selftests/huge_gem_object.c"
343 #include "selftests/huge_pages.c"
344 #include "selftests/i915_gem_object.c"
345 #include "selftests/i915_gem_coherency.c"
346 #endif
347