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 fence		*fence;
38 };
39 
40 /**
41  * amdgpu_sync_create - zero init sync object
42  *
43  * @sync: sync object to initialize
44  *
45  * Just clear the sync object for now.
46  */
47 void amdgpu_sync_create(struct amdgpu_sync *sync)
48 {
49 	unsigned i;
50 
51 	for (i = 0; i < AMDGPU_NUM_SYNCS; ++i)
52 		sync->semaphores[i] = NULL;
53 
54 	for (i = 0; i < AMDGPU_MAX_RINGS; ++i)
55 		sync->sync_to[i] = NULL;
56 
57 	hash_init(sync->fences);
58 	sync->last_vm_update = NULL;
59 }
60 
61 static bool amdgpu_sync_same_dev(struct amdgpu_device *adev, struct fence *f)
62 {
63 	struct amdgpu_fence *a_fence = to_amdgpu_fence(f);
64 	struct amd_sched_fence *s_fence = to_amd_sched_fence(f);
65 
66 	if (a_fence)
67 		return a_fence->ring->adev == adev;
68 	if (s_fence)
69 		return (struct amdgpu_device *)s_fence->scheduler->priv == adev;
70 	return false;
71 }
72 
73 static bool amdgpu_sync_test_owner(struct fence *f, void *owner)
74 {
75 	struct amdgpu_fence *a_fence = to_amdgpu_fence(f);
76 	struct amd_sched_fence *s_fence = to_amd_sched_fence(f);
77 	if (s_fence)
78 		return s_fence->owner == owner;
79 	if (a_fence)
80 		return a_fence->owner == owner;
81 	return false;
82 }
83 
84 /**
85  * amdgpu_sync_fence - remember to sync to this fence
86  *
87  * @sync: sync object to add fence to
88  * @fence: fence to sync to
89  *
90  */
91 int amdgpu_sync_fence(struct amdgpu_device *adev, struct amdgpu_sync *sync,
92 		      struct fence *f)
93 {
94 	struct amdgpu_sync_entry *e;
95 	struct amdgpu_fence *fence;
96 	struct amdgpu_fence *other;
97 	struct fence *tmp, *later;
98 
99 	if (!f)
100 		return 0;
101 
102 	if (amdgpu_sync_same_dev(adev, f) &&
103 	    amdgpu_sync_test_owner(f, AMDGPU_FENCE_OWNER_VM)) {
104 		if (sync->last_vm_update) {
105 			tmp = sync->last_vm_update;
106 			BUG_ON(f->context != tmp->context);
107 			later = (f->seqno - tmp->seqno <= INT_MAX) ? f : tmp;
108 			sync->last_vm_update = fence_get(later);
109 			fence_put(tmp);
110 		} else
111 			sync->last_vm_update = fence_get(f);
112 	}
113 
114 	fence = to_amdgpu_fence(f);
115 	if (!fence || fence->ring->adev != adev) {
116 		hash_for_each_possible(sync->fences, e, node, f->context) {
117 			struct fence *new;
118 			if (unlikely(e->fence->context != f->context))
119 				continue;
120 			new = fence_get(fence_later(e->fence, f));
121 			if (new) {
122 				fence_put(e->fence);
123 				e->fence = new;
124 			}
125 			return 0;
126 		}
127 
128 		e = kmalloc(sizeof(struct amdgpu_sync_entry), GFP_KERNEL);
129 		if (!e)
130 			return -ENOMEM;
131 
132 		hash_add(sync->fences, &e->node, f->context);
133 		e->fence = fence_get(f);
134 		return 0;
135 	}
136 
137 	other = sync->sync_to[fence->ring->idx];
138 	sync->sync_to[fence->ring->idx] = amdgpu_fence_ref(
139 		amdgpu_fence_later(fence, other));
140 	amdgpu_fence_unref(&other);
141 
142 	return 0;
143 }
144 
145 static void *amdgpu_sync_get_owner(struct fence *f)
146 {
147 	struct amdgpu_fence *a_fence = to_amdgpu_fence(f);
148 	struct amd_sched_fence *s_fence = to_amd_sched_fence(f);
149 
150 	if (s_fence)
151 		return s_fence->owner;
152 	else if (a_fence)
153 		return a_fence->owner;
154 	return AMDGPU_FENCE_OWNER_UNDEFINED;
155 }
156 
157 /**
158  * amdgpu_sync_resv - use the semaphores to sync to a reservation object
159  *
160  * @sync: sync object to add fences from reservation object to
161  * @resv: reservation object with embedded fence
162  * @shared: true if we should only sync to the exclusive fence
163  *
164  * Sync to the fence using the semaphore objects
165  */
166 int amdgpu_sync_resv(struct amdgpu_device *adev,
167 		     struct amdgpu_sync *sync,
168 		     struct reservation_object *resv,
169 		     void *owner)
170 {
171 	struct reservation_object_list *flist;
172 	struct fence *f;
173 	void *fence_owner;
174 	unsigned i;
175 	int r = 0;
176 
177 	if (resv == NULL)
178 		return -EINVAL;
179 
180 	/* always sync to the exclusive fence */
181 	f = reservation_object_get_excl(resv);
182 	r = amdgpu_sync_fence(adev, sync, f);
183 
184 	flist = reservation_object_get_list(resv);
185 	if (!flist || r)
186 		return r;
187 
188 	for (i = 0; i < flist->shared_count; ++i) {
189 		f = rcu_dereference_protected(flist->shared[i],
190 					      reservation_object_held(resv));
191 		if (amdgpu_sync_same_dev(adev, f)) {
192 			/* VM updates are only interesting
193 			 * for other VM updates and moves.
194 			 */
195 			fence_owner = amdgpu_sync_get_owner(f);
196 			if ((owner != AMDGPU_FENCE_OWNER_MOVE) &&
197 			    (fence_owner != AMDGPU_FENCE_OWNER_MOVE) &&
198 			    ((owner == AMDGPU_FENCE_OWNER_VM) !=
199 			     (fence_owner == AMDGPU_FENCE_OWNER_VM)))
200 				continue;
201 
202 			/* Ignore fence from the same owner as
203 			 * long as it isn't undefined.
204 			 */
205 			if (owner != AMDGPU_FENCE_OWNER_UNDEFINED &&
206 			    fence_owner == owner)
207 				continue;
208 		}
209 
210 		r = amdgpu_sync_fence(adev, sync, f);
211 		if (r)
212 			break;
213 	}
214 	return r;
215 }
216 
217 struct fence *amdgpu_sync_get_fence(struct amdgpu_sync *sync)
218 {
219 	struct amdgpu_sync_entry *e;
220 	struct hlist_node *tmp;
221 	struct fence *f;
222 	int i;
223 
224 	hash_for_each_safe(sync->fences, i, tmp, e, node) {
225 
226 		f = e->fence;
227 
228 		hash_del(&e->node);
229 		kfree(e);
230 
231 		if (!fence_is_signaled(f))
232 			return f;
233 
234 		fence_put(f);
235 	}
236 	return NULL;
237 }
238 
239 int amdgpu_sync_wait(struct amdgpu_sync *sync)
240 {
241 	struct amdgpu_sync_entry *e;
242 	struct hlist_node *tmp;
243 	int i, r;
244 
245 	hash_for_each_safe(sync->fences, i, tmp, e, node) {
246 		r = fence_wait(e->fence, false);
247 		if (r)
248 			return r;
249 
250 		hash_del(&e->node);
251 		fence_put(e->fence);
252 		kfree(e);
253 	}
254 	return 0;
255 }
256 
257 /**
258  * amdgpu_sync_rings - sync ring to all registered fences
259  *
260  * @sync: sync object to use
261  * @ring: ring that needs sync
262  *
263  * Ensure that all registered fences are signaled before letting
264  * the ring continue. The caller must hold the ring lock.
265  */
266 int amdgpu_sync_rings(struct amdgpu_sync *sync,
267 		      struct amdgpu_ring *ring)
268 {
269 	struct amdgpu_device *adev = ring->adev;
270 	unsigned count = 0;
271 	int i, r;
272 
273 	for (i = 0; i < AMDGPU_MAX_RINGS; ++i) {
274 		struct amdgpu_fence *fence = sync->sync_to[i];
275 		struct amdgpu_semaphore *semaphore;
276 		struct amdgpu_ring *other = adev->rings[i];
277 
278 		/* check if we really need to sync */
279 		if (!amdgpu_fence_need_sync(fence, ring))
280 			continue;
281 
282 		/* prevent GPU deadlocks */
283 		if (!other->ready) {
284 			dev_err(adev->dev, "Syncing to a disabled ring!");
285 			return -EINVAL;
286 		}
287 
288 		if (amdgpu_enable_scheduler || (count >= AMDGPU_NUM_SYNCS)) {
289 			/* not enough room, wait manually */
290 			r = fence_wait(&fence->base, false);
291 			if (r)
292 				return r;
293 			continue;
294 		}
295 		r = amdgpu_semaphore_create(adev, &semaphore);
296 		if (r)
297 			return r;
298 
299 		sync->semaphores[count++] = semaphore;
300 
301 		/* allocate enough space for sync command */
302 		r = amdgpu_ring_alloc(other, 16);
303 		if (r)
304 			return r;
305 
306 		/* emit the signal semaphore */
307 		if (!amdgpu_semaphore_emit_signal(other, semaphore)) {
308 			/* signaling wasn't successful wait manually */
309 			amdgpu_ring_undo(other);
310 			r = fence_wait(&fence->base, false);
311 			if (r)
312 				return r;
313 			continue;
314 		}
315 
316 		/* we assume caller has already allocated space on waiters ring */
317 		if (!amdgpu_semaphore_emit_wait(ring, semaphore)) {
318 			/* waiting wasn't successful wait manually */
319 			amdgpu_ring_undo(other);
320 			r = fence_wait(&fence->base, false);
321 			if (r)
322 				return r;
323 			continue;
324 		}
325 
326 		amdgpu_ring_commit(other);
327 		amdgpu_fence_note_sync(fence, ring);
328 	}
329 
330 	return 0;
331 }
332 
333 /**
334  * amdgpu_sync_free - free the sync object
335  *
336  * @adev: amdgpu_device pointer
337  * @sync: sync object to use
338  * @fence: fence to use for the free
339  *
340  * Free the sync object by freeing all semaphores in it.
341  */
342 void amdgpu_sync_free(struct amdgpu_device *adev,
343 		      struct amdgpu_sync *sync,
344 		      struct fence *fence)
345 {
346 	struct amdgpu_sync_entry *e;
347 	struct hlist_node *tmp;
348 	unsigned i;
349 
350 	hash_for_each_safe(sync->fences, i, tmp, e, node) {
351 		hash_del(&e->node);
352 		fence_put(e->fence);
353 		kfree(e);
354 	}
355 
356 	for (i = 0; i < AMDGPU_NUM_SYNCS; ++i)
357 		amdgpu_semaphore_free(adev, &sync->semaphores[i], fence);
358 
359 	for (i = 0; i < AMDGPU_MAX_RINGS; ++i)
360 		amdgpu_fence_unref(&sync->sync_to[i]);
361 
362 	fence_put(sync->last_vm_update);
363 }
364