1 /*
2  * Copyright 2014 Advanced Micro Devices, Inc.
3  * All Rights Reserved.
4  *
5  * Permission is hereby granted, free of charge, to any person obtaining a
6  * copy of this software and associated documentation files (the
7  * "Software"), to deal in the Software without restriction, including
8  * without limitation the rights to use, copy, modify, merge, publish,
9  * distribute, sub license, and/or sell copies of the Software, and to
10  * permit persons to whom the Software is furnished to do so, subject to
11  * the following conditions:
12  *
13  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
14  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
15  * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
16  * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
17  * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
18  * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
19  * USE OR OTHER DEALINGS IN THE SOFTWARE.
20  *
21  * The above copyright notice and this permission notice (including the
22  * next paragraph) shall be included in all copies or substantial portions
23  * of the Software.
24  *
25  */
26 /*
27  * Authors:
28  *    Christian König <christian.koenig@amd.com>
29  */
30 
31 #include <drm/drmP.h>
32 #include "amdgpu.h"
33 #include "amdgpu_trace.h"
34 
35 struct amdgpu_sync_entry {
36 	struct hlist_node	node;
37 	struct dma_fence	*fence;
38 };
39 
40 static struct kmem_cache *amdgpu_sync_slab;
41 
42 /**
43  * amdgpu_sync_create - zero init sync object
44  *
45  * @sync: sync object to initialize
46  *
47  * Just clear the sync object for now.
48  */
49 void amdgpu_sync_create(struct amdgpu_sync *sync)
50 {
51 	hash_init(sync->fences);
52 	sync->last_vm_update = NULL;
53 }
54 
55 /**
56  * amdgpu_sync_same_dev - test if fence belong to us
57  *
58  * @adev: amdgpu device to use for the test
59  * @f: fence to test
60  *
61  * Test if the fence was issued by us.
62  */
63 static bool amdgpu_sync_same_dev(struct amdgpu_device *adev,
64 				 struct dma_fence *f)
65 {
66 	struct amd_sched_fence *s_fence = to_amd_sched_fence(f);
67 
68 	if (s_fence) {
69 		struct amdgpu_ring *ring;
70 
71 		ring = container_of(s_fence->sched, struct amdgpu_ring, sched);
72 		return ring->adev == adev;
73 	}
74 
75 	return false;
76 }
77 
78 /**
79  * amdgpu_sync_get_owner - extract the owner of a fence
80  *
81  * @fence: fence get the owner from
82  *
83  * Extract who originally created the fence.
84  */
85 static void *amdgpu_sync_get_owner(struct dma_fence *f)
86 {
87 	struct amd_sched_fence *s_fence = to_amd_sched_fence(f);
88 
89 	if (s_fence)
90 		return s_fence->owner;
91 
92 	return AMDGPU_FENCE_OWNER_UNDEFINED;
93 }
94 
95 /**
96  * amdgpu_sync_keep_later - Keep the later fence
97  *
98  * @keep: existing fence to test
99  * @fence: new fence
100  *
101  * Either keep the existing fence or the new one, depending which one is later.
102  */
103 static void amdgpu_sync_keep_later(struct dma_fence **keep,
104 				   struct dma_fence *fence)
105 {
106 	if (*keep && dma_fence_is_later(*keep, fence))
107 		return;
108 
109 	dma_fence_put(*keep);
110 	*keep = dma_fence_get(fence);
111 }
112 
113 /**
114  * amdgpu_sync_add_later - add the fence to the hash
115  *
116  * @sync: sync object to add the fence to
117  * @f: fence to add
118  *
119  * Tries to add the fence to an existing hash entry. Returns true when an entry
120  * was found, false otherwise.
121  */
122 static bool amdgpu_sync_add_later(struct amdgpu_sync *sync, struct dma_fence *f)
123 {
124 	struct amdgpu_sync_entry *e;
125 
126 	hash_for_each_possible(sync->fences, e, node, f->context) {
127 		if (unlikely(e->fence->context != f->context))
128 			continue;
129 
130 		amdgpu_sync_keep_later(&e->fence, f);
131 		return true;
132 	}
133 	return false;
134 }
135 
136 /**
137  * amdgpu_sync_fence - remember to sync to this fence
138  *
139  * @sync: sync object to add fence to
140  * @fence: fence to sync to
141  *
142  */
143 int amdgpu_sync_fence(struct amdgpu_device *adev, struct amdgpu_sync *sync,
144 		      struct dma_fence *f)
145 {
146 	struct amdgpu_sync_entry *e;
147 
148 	if (!f)
149 		return 0;
150 
151 	if (amdgpu_sync_same_dev(adev, f) &&
152 	    amdgpu_sync_get_owner(f) == AMDGPU_FENCE_OWNER_VM)
153 		amdgpu_sync_keep_later(&sync->last_vm_update, f);
154 
155 	if (amdgpu_sync_add_later(sync, f))
156 		return 0;
157 
158 	e = kmem_cache_alloc(amdgpu_sync_slab, GFP_KERNEL);
159 	if (!e)
160 		return -ENOMEM;
161 
162 	hash_add(sync->fences, &e->node, f->context);
163 	e->fence = dma_fence_get(f);
164 	return 0;
165 }
166 
167 /**
168  * amdgpu_sync_resv - sync to a reservation object
169  *
170  * @sync: sync object to add fences from reservation object to
171  * @resv: reservation object with embedded fence
172  * @shared: true if we should only sync to the exclusive fence
173  *
174  * Sync to the fence
175  */
176 int amdgpu_sync_resv(struct amdgpu_device *adev,
177 		     struct amdgpu_sync *sync,
178 		     struct reservation_object *resv,
179 		     void *owner)
180 {
181 	struct reservation_object_list *flist;
182 	struct dma_fence *f;
183 	void *fence_owner;
184 	unsigned i;
185 	int r = 0;
186 
187 	if (resv == NULL)
188 		return -EINVAL;
189 
190 	/* always sync to the exclusive fence */
191 	f = reservation_object_get_excl(resv);
192 	r = amdgpu_sync_fence(adev, sync, f);
193 
194 	flist = reservation_object_get_list(resv);
195 	if (!flist || r)
196 		return r;
197 
198 	for (i = 0; i < flist->shared_count; ++i) {
199 		f = rcu_dereference_protected(flist->shared[i],
200 					      reservation_object_held(resv));
201 		if (amdgpu_sync_same_dev(adev, f)) {
202 			/* VM updates are only interesting
203 			 * for other VM updates and moves.
204 			 */
205 			fence_owner = amdgpu_sync_get_owner(f);
206 			if ((owner != AMDGPU_FENCE_OWNER_UNDEFINED) &&
207 			    (fence_owner != AMDGPU_FENCE_OWNER_UNDEFINED) &&
208 			    ((owner == AMDGPU_FENCE_OWNER_VM) !=
209 			     (fence_owner == AMDGPU_FENCE_OWNER_VM)))
210 				continue;
211 
212 			/* Ignore fence from the same owner as
213 			 * long as it isn't undefined.
214 			 */
215 			if (owner != AMDGPU_FENCE_OWNER_UNDEFINED &&
216 			    fence_owner == owner)
217 				continue;
218 		}
219 
220 		r = amdgpu_sync_fence(adev, sync, f);
221 		if (r)
222 			break;
223 	}
224 	return r;
225 }
226 
227 /**
228  * amdgpu_sync_peek_fence - get the next fence not signaled yet
229  *
230  * @sync: the sync object
231  * @ring: optional ring to use for test
232  *
233  * Returns the next fence not signaled yet without removing it from the sync
234  * object.
235  */
236 struct dma_fence *amdgpu_sync_peek_fence(struct amdgpu_sync *sync,
237 					 struct amdgpu_ring *ring)
238 {
239 	struct amdgpu_sync_entry *e;
240 	struct hlist_node *tmp;
241 	int i;
242 
243 	hash_for_each_safe(sync->fences, i, tmp, e, node) {
244 		struct dma_fence *f = e->fence;
245 		struct amd_sched_fence *s_fence = to_amd_sched_fence(f);
246 
247 		if (ring && s_fence) {
248 			/* For fences from the same ring it is sufficient
249 			 * when they are scheduled.
250 			 */
251 			if (s_fence->sched == &ring->sched) {
252 				if (dma_fence_is_signaled(&s_fence->scheduled))
253 					continue;
254 
255 				return &s_fence->scheduled;
256 			}
257 		}
258 
259 		if (dma_fence_is_signaled(f)) {
260 			hash_del(&e->node);
261 			dma_fence_put(f);
262 			kmem_cache_free(amdgpu_sync_slab, e);
263 			continue;
264 		}
265 
266 		return f;
267 	}
268 
269 	return NULL;
270 }
271 
272 /**
273  * amdgpu_sync_get_fence - get the next fence from the sync object
274  *
275  * @sync: sync object to use
276  *
277  * Get and removes the next fence from the sync object not signaled yet.
278  */
279 struct dma_fence *amdgpu_sync_get_fence(struct amdgpu_sync *sync)
280 {
281 	struct amdgpu_sync_entry *e;
282 	struct hlist_node *tmp;
283 	struct dma_fence *f;
284 	int i;
285 
286 	hash_for_each_safe(sync->fences, i, tmp, e, node) {
287 
288 		f = e->fence;
289 
290 		hash_del(&e->node);
291 		kmem_cache_free(amdgpu_sync_slab, e);
292 
293 		if (!dma_fence_is_signaled(f))
294 			return f;
295 
296 		dma_fence_put(f);
297 	}
298 	return NULL;
299 }
300 
301 /**
302  * amdgpu_sync_free - free the sync object
303  *
304  * @sync: sync object to use
305  *
306  * Free the sync object.
307  */
308 void amdgpu_sync_free(struct amdgpu_sync *sync)
309 {
310 	struct amdgpu_sync_entry *e;
311 	struct hlist_node *tmp;
312 	unsigned i;
313 
314 	hash_for_each_safe(sync->fences, i, tmp, e, node) {
315 		hash_del(&e->node);
316 		dma_fence_put(e->fence);
317 		kmem_cache_free(amdgpu_sync_slab, e);
318 	}
319 
320 	dma_fence_put(sync->last_vm_update);
321 }
322 
323 /**
324  * amdgpu_sync_init - init sync object subsystem
325  *
326  * Allocate the slab allocator.
327  */
328 int amdgpu_sync_init(void)
329 {
330 	amdgpu_sync_slab = kmem_cache_create(
331 		"amdgpu_sync", sizeof(struct amdgpu_sync_entry), 0,
332 		SLAB_HWCACHE_ALIGN, NULL);
333 	if (!amdgpu_sync_slab)
334 		return -ENOMEM;
335 
336 	return 0;
337 }
338 
339 /**
340  * amdgpu_sync_fini - fini sync object subsystem
341  *
342  * Free the slab allocator.
343  */
344 void amdgpu_sync_fini(void)
345 {
346 	kmem_cache_destroy(amdgpu_sync_slab);
347 }
348