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 "radeon.h"
33 #include "radeon_trace.h"
34 
35 /**
36  * radeon_sync_create - zero init sync object
37  *
38  * @sync: sync object to initialize
39  *
40  * Just clear the sync object for now.
41  */
42 void radeon_sync_create(struct radeon_sync *sync)
43 {
44 	unsigned i;
45 
46 	for (i = 0; i < RADEON_NUM_SYNCS; ++i)
47 		sync->semaphores[i] = NULL;
48 
49 	for (i = 0; i < RADEON_NUM_RINGS; ++i)
50 		sync->sync_to[i] = NULL;
51 
52 	sync->last_vm_update = NULL;
53 }
54 
55 /**
56  * radeon_sync_fence - use the semaphore to sync to a fence
57  *
58  * @sync: sync object to add fence to
59  * @fence: fence to sync to
60  *
61  * Sync to the fence using the semaphore objects
62  */
63 void radeon_sync_fence(struct radeon_sync *sync,
64 		       struct radeon_fence *fence)
65 {
66 	struct radeon_fence *other;
67 
68 	if (!fence)
69 		return;
70 
71 	other = sync->sync_to[fence->ring];
72 	sync->sync_to[fence->ring] = radeon_fence_later(fence, other);
73 
74 	if (fence->is_vm_update) {
75 		other = sync->last_vm_update;
76 		sync->last_vm_update = radeon_fence_later(fence, other);
77 	}
78 }
79 
80 /**
81  * radeon_sync_resv - use the semaphores to sync to a reservation object
82  *
83  * @sync: sync object to add fences from reservation object to
84  * @resv: reservation object with embedded fence
85  * @shared: true if we should only sync to the exclusive fence
86  *
87  * Sync to the fence using the semaphore objects
88  */
89 int radeon_sync_resv(struct radeon_device *rdev,
90 		     struct radeon_sync *sync,
91 		     struct reservation_object *resv,
92 		     bool shared)
93 {
94 	struct reservation_object_list *flist;
95 	struct dma_fence *f;
96 	struct radeon_fence *fence;
97 	unsigned i;
98 	int r = 0;
99 
100 	/* always sync to the exclusive fence */
101 	f = reservation_object_get_excl(resv);
102 	fence = f ? to_radeon_fence(f) : NULL;
103 	if (fence && fence->rdev == rdev)
104 		radeon_sync_fence(sync, fence);
105 	else if (f)
106 		r = dma_fence_wait(f, true);
107 
108 	flist = reservation_object_get_list(resv);
109 	if (shared || !flist || r)
110 		return r;
111 
112 	for (i = 0; i < flist->shared_count; ++i) {
113 		f = rcu_dereference_protected(flist->shared[i],
114 					      reservation_object_held(resv));
115 		fence = to_radeon_fence(f);
116 		if (fence && fence->rdev == rdev)
117 			radeon_sync_fence(sync, fence);
118 		else
119 			r = dma_fence_wait(f, true);
120 
121 		if (r)
122 			break;
123 	}
124 	return r;
125 }
126 
127 /**
128  * radeon_sync_rings - sync ring to all registered fences
129  *
130  * @rdev: radeon_device pointer
131  * @sync: sync object to use
132  * @ring: ring that needs sync
133  *
134  * Ensure that all registered fences are signaled before letting
135  * the ring continue. The caller must hold the ring lock.
136  */
137 int radeon_sync_rings(struct radeon_device *rdev,
138 		      struct radeon_sync *sync,
139 		      int ring)
140 {
141 	unsigned count = 0;
142 	int i, r;
143 
144 	for (i = 0; i < RADEON_NUM_RINGS; ++i) {
145 		struct radeon_fence *fence = sync->sync_to[i];
146 		struct radeon_semaphore *semaphore;
147 
148 		/* check if we really need to sync */
149 		if (!radeon_fence_need_sync(fence, ring))
150 			continue;
151 
152 		/* prevent GPU deadlocks */
153 		if (!rdev->ring[i].ready) {
154 			dev_err(rdev->dev, "Syncing to a disabled ring!");
155 			return -EINVAL;
156 		}
157 
158 		if (count >= RADEON_NUM_SYNCS) {
159 			/* not enough room, wait manually */
160 			r = radeon_fence_wait(fence, false);
161 			if (r)
162 				return r;
163 			continue;
164 		}
165 		r = radeon_semaphore_create(rdev, &semaphore);
166 		if (r)
167 			return r;
168 
169 		sync->semaphores[count++] = semaphore;
170 
171 		/* allocate enough space for sync command */
172 		r = radeon_ring_alloc(rdev, &rdev->ring[i], 16);
173 		if (r)
174 			return r;
175 
176 		/* emit the signal semaphore */
177 		if (!radeon_semaphore_emit_signal(rdev, i, semaphore)) {
178 			/* signaling wasn't successful wait manually */
179 			radeon_ring_undo(&rdev->ring[i]);
180 			r = radeon_fence_wait(fence, false);
181 			if (r)
182 				return r;
183 			continue;
184 		}
185 
186 		/* we assume caller has already allocated space on waiters ring */
187 		if (!radeon_semaphore_emit_wait(rdev, ring, semaphore)) {
188 			/* waiting wasn't successful wait manually */
189 			radeon_ring_undo(&rdev->ring[i]);
190 			r = radeon_fence_wait(fence, false);
191 			if (r)
192 				return r;
193 			continue;
194 		}
195 
196 		radeon_ring_commit(rdev, &rdev->ring[i], false);
197 		radeon_fence_note_sync(fence, ring);
198 	}
199 
200 	return 0;
201 }
202 
203 /**
204  * radeon_sync_free - free the sync object
205  *
206  * @rdev: radeon_device pointer
207  * @sync: sync object to use
208  * @fence: fence to use for the free
209  *
210  * Free the sync object by freeing all semaphores in it.
211  */
212 void radeon_sync_free(struct radeon_device *rdev,
213 		      struct radeon_sync *sync,
214 		      struct radeon_fence *fence)
215 {
216 	unsigned i;
217 
218 	for (i = 0; i < RADEON_NUM_SYNCS; ++i)
219 		radeon_semaphore_free(rdev, &sync->semaphores[i], fence);
220 }
221