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 "radeon.h"
32 #include "radeon_trace.h"
33 
34 /**
35  * radeon_sync_create - zero init sync object
36  *
37  * @sync: sync object to initialize
38  *
39  * Just clear the sync object for now.
40  */
41 void radeon_sync_create(struct radeon_sync *sync)
42 {
43 	unsigned i;
44 
45 	for (i = 0; i < RADEON_NUM_SYNCS; ++i)
46 		sync->semaphores[i] = NULL;
47 
48 	for (i = 0; i < RADEON_NUM_RINGS; ++i)
49 		sync->sync_to[i] = NULL;
50 
51 	sync->last_vm_update = NULL;
52 }
53 
54 /**
55  * radeon_sync_fence - use the semaphore to sync to a fence
56  *
57  * @sync: sync object to add fence to
58  * @fence: fence to sync to
59  *
60  * Sync to the fence using the semaphore objects
61  */
62 void radeon_sync_fence(struct radeon_sync *sync,
63 		       struct radeon_fence *fence)
64 {
65 	struct radeon_fence *other;
66 
67 	if (!fence)
68 		return;
69 
70 	other = sync->sync_to[fence->ring];
71 	sync->sync_to[fence->ring] = radeon_fence_later(fence, other);
72 
73 	if (fence->is_vm_update) {
74 		other = sync->last_vm_update;
75 		sync->last_vm_update = radeon_fence_later(fence, other);
76 	}
77 }
78 
79 /**
80  * radeon_sync_resv - use the semaphores to sync to a reservation object
81  *
82  * @sync: sync object to add fences from reservation object to
83  * @resv: reservation object with embedded fence
84  * @shared: true if we should only sync to the exclusive fence
85  *
86  * Sync to the fence using the semaphore objects
87  */
88 int radeon_sync_resv(struct radeon_device *rdev,
89 		     struct radeon_sync *sync,
90 		     struct dma_resv *resv,
91 		     bool shared)
92 {
93 	struct dma_resv_list *flist;
94 	struct dma_fence *f;
95 	struct radeon_fence *fence;
96 	unsigned i;
97 	int r = 0;
98 
99 	/* always sync to the exclusive fence */
100 	f = dma_resv_get_excl(resv);
101 	fence = f ? to_radeon_fence(f) : NULL;
102 	if (fence && fence->rdev == rdev)
103 		radeon_sync_fence(sync, fence);
104 	else if (f)
105 		r = dma_fence_wait(f, true);
106 
107 	flist = dma_resv_get_list(resv);
108 	if (shared || !flist || r)
109 		return r;
110 
111 	for (i = 0; i < flist->shared_count; ++i) {
112 		f = rcu_dereference_protected(flist->shared[i],
113 					      dma_resv_held(resv));
114 		fence = to_radeon_fence(f);
115 		if (fence && fence->rdev == rdev)
116 			radeon_sync_fence(sync, fence);
117 		else
118 			r = dma_fence_wait(f, true);
119 
120 		if (r)
121 			break;
122 	}
123 	return r;
124 }
125 
126 /**
127  * radeon_sync_rings - sync ring to all registered fences
128  *
129  * @rdev: radeon_device pointer
130  * @sync: sync object to use
131  * @ring: ring that needs sync
132  *
133  * Ensure that all registered fences are signaled before letting
134  * the ring continue. The caller must hold the ring lock.
135  */
136 int radeon_sync_rings(struct radeon_device *rdev,
137 		      struct radeon_sync *sync,
138 		      int ring)
139 {
140 	unsigned count = 0;
141 	int i, r;
142 
143 	for (i = 0; i < RADEON_NUM_RINGS; ++i) {
144 		struct radeon_fence *fence = sync->sync_to[i];
145 		struct radeon_semaphore *semaphore;
146 
147 		/* check if we really need to sync */
148 		if (!radeon_fence_need_sync(fence, ring))
149 			continue;
150 
151 		/* prevent GPU deadlocks */
152 		if (!rdev->ring[i].ready) {
153 			dev_err(rdev->dev, "Syncing to a disabled ring!");
154 			return -EINVAL;
155 		}
156 
157 		if (count >= RADEON_NUM_SYNCS) {
158 			/* not enough room, wait manually */
159 			r = radeon_fence_wait(fence, false);
160 			if (r)
161 				return r;
162 			continue;
163 		}
164 		r = radeon_semaphore_create(rdev, &semaphore);
165 		if (r)
166 			return r;
167 
168 		sync->semaphores[count++] = semaphore;
169 
170 		/* allocate enough space for sync command */
171 		r = radeon_ring_alloc(rdev, &rdev->ring[i], 16);
172 		if (r)
173 			return r;
174 
175 		/* emit the signal semaphore */
176 		if (!radeon_semaphore_emit_signal(rdev, i, semaphore)) {
177 			/* signaling wasn't successful wait manually */
178 			radeon_ring_undo(&rdev->ring[i]);
179 			r = radeon_fence_wait(fence, false);
180 			if (r)
181 				return r;
182 			continue;
183 		}
184 
185 		/* we assume caller has already allocated space on waiters ring */
186 		if (!radeon_semaphore_emit_wait(rdev, ring, semaphore)) {
187 			/* waiting wasn't successful wait manually */
188 			radeon_ring_undo(&rdev->ring[i]);
189 			r = radeon_fence_wait(fence, false);
190 			if (r)
191 				return r;
192 			continue;
193 		}
194 
195 		radeon_ring_commit(rdev, &rdev->ring[i], false);
196 		radeon_fence_note_sync(fence, ring);
197 	}
198 
199 	return 0;
200 }
201 
202 /**
203  * radeon_sync_free - free the sync object
204  *
205  * @rdev: radeon_device pointer
206  * @sync: sync object to use
207  * @fence: fence to use for the free
208  *
209  * Free the sync object by freeing all semaphores in it.
210  */
211 void radeon_sync_free(struct radeon_device *rdev,
212 		      struct radeon_sync *sync,
213 		      struct radeon_fence *fence)
214 {
215 	unsigned i;
216 
217 	for (i = 0; i < RADEON_NUM_SYNCS; ++i)
218 		radeon_semaphore_free(rdev, &sync->semaphores[i], fence);
219 }
220