xref: /openbmc/linux/drivers/gpu/drm/amd/amdgpu/amdgpu_sync.c (revision bbde9fc1824aab58bc78c084163007dd6c03fe5b)
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 /**
36  * amdgpu_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 amdgpu_sync_create(struct amdgpu_sync *sync)
43 {
44 	unsigned i;
45 
46 	for (i = 0; i < AMDGPU_NUM_SYNCS; ++i)
47 		sync->semaphores[i] = NULL;
48 
49 	for (i = 0; i < AMDGPU_MAX_RINGS; ++i)
50 		sync->sync_to[i] = NULL;
51 
52 	sync->last_vm_update = NULL;
53 }
54 
55 /**
56  * amdgpu_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 amdgpu_sync_fence(struct amdgpu_sync *sync,
64 		       struct amdgpu_fence *fence)
65 {
66 	struct amdgpu_fence *other;
67 
68 	if (!fence)
69 		return;
70 
71 	other = sync->sync_to[fence->ring->idx];
72 	sync->sync_to[fence->ring->idx] = amdgpu_fence_ref(
73 		amdgpu_fence_later(fence, other));
74 	amdgpu_fence_unref(&other);
75 
76 	if (fence->owner == AMDGPU_FENCE_OWNER_VM) {
77 		other = sync->last_vm_update;
78 		sync->last_vm_update = amdgpu_fence_ref(
79 			amdgpu_fence_later(fence, other));
80 		amdgpu_fence_unref(&other);
81 	}
82 }
83 
84 /**
85  * amdgpu_sync_resv - use the semaphores to sync to a reservation object
86  *
87  * @sync: sync object to add fences from reservation object to
88  * @resv: reservation object with embedded fence
89  * @shared: true if we should only sync to the exclusive fence
90  *
91  * Sync to the fence using the semaphore objects
92  */
93 int amdgpu_sync_resv(struct amdgpu_device *adev,
94 		     struct amdgpu_sync *sync,
95 		     struct reservation_object *resv,
96 		     void *owner)
97 {
98 	struct reservation_object_list *flist;
99 	struct fence *f;
100 	struct amdgpu_fence *fence;
101 	unsigned i;
102 	int r = 0;
103 
104 	if (resv == NULL)
105 		return -EINVAL;
106 
107 	/* always sync to the exclusive fence */
108 	f = reservation_object_get_excl(resv);
109 	fence = f ? to_amdgpu_fence(f) : NULL;
110 	if (fence && fence->ring->adev == adev)
111 		amdgpu_sync_fence(sync, fence);
112 	else if (f)
113 		r = fence_wait(f, true);
114 
115 	flist = reservation_object_get_list(resv);
116 	if (!flist || r)
117 		return r;
118 
119 	for (i = 0; i < flist->shared_count; ++i) {
120 		f = rcu_dereference_protected(flist->shared[i],
121 					      reservation_object_held(resv));
122 		fence = f ? to_amdgpu_fence(f) : NULL;
123 		if (fence && fence->ring->adev == adev) {
124 			if (fence->owner != owner ||
125 			    fence->owner == AMDGPU_FENCE_OWNER_UNDEFINED)
126 				amdgpu_sync_fence(sync, fence);
127 		} else if (f) {
128 			r = fence_wait(f, true);
129 			if (r)
130 				break;
131 		}
132 	}
133 	return r;
134 }
135 
136 /**
137  * amdgpu_sync_rings - sync ring to all registered fences
138  *
139  * @sync: sync object to use
140  * @ring: ring that needs sync
141  *
142  * Ensure that all registered fences are signaled before letting
143  * the ring continue. The caller must hold the ring lock.
144  */
145 int amdgpu_sync_rings(struct amdgpu_sync *sync,
146 		      struct amdgpu_ring *ring)
147 {
148 	struct amdgpu_device *adev = ring->adev;
149 	unsigned count = 0;
150 	int i, r;
151 
152 	for (i = 0; i < AMDGPU_MAX_RINGS; ++i) {
153 		struct amdgpu_fence *fence = sync->sync_to[i];
154 		struct amdgpu_semaphore *semaphore;
155 		struct amdgpu_ring *other = adev->rings[i];
156 
157 		/* check if we really need to sync */
158 		if (!amdgpu_fence_need_sync(fence, ring))
159 			continue;
160 
161 		/* prevent GPU deadlocks */
162 		if (!other->ready) {
163 			dev_err(adev->dev, "Syncing to a disabled ring!");
164 			return -EINVAL;
165 		}
166 
167 		if (count >= AMDGPU_NUM_SYNCS) {
168 			/* not enough room, wait manually */
169 			r = amdgpu_fence_wait(fence, false);
170 			if (r)
171 				return r;
172 			continue;
173 		}
174 		r = amdgpu_semaphore_create(adev, &semaphore);
175 		if (r)
176 			return r;
177 
178 		sync->semaphores[count++] = semaphore;
179 
180 		/* allocate enough space for sync command */
181 		r = amdgpu_ring_alloc(other, 16);
182 		if (r)
183 			return r;
184 
185 		/* emit the signal semaphore */
186 		if (!amdgpu_semaphore_emit_signal(other, semaphore)) {
187 			/* signaling wasn't successful wait manually */
188 			amdgpu_ring_undo(other);
189 			r = amdgpu_fence_wait(fence, false);
190 			if (r)
191 				return r;
192 			continue;
193 		}
194 
195 		/* we assume caller has already allocated space on waiters ring */
196 		if (!amdgpu_semaphore_emit_wait(ring, semaphore)) {
197 			/* waiting wasn't successful wait manually */
198 			amdgpu_ring_undo(other);
199 			r = amdgpu_fence_wait(fence, false);
200 			if (r)
201 				return r;
202 			continue;
203 		}
204 
205 		amdgpu_ring_commit(other);
206 		amdgpu_fence_note_sync(fence, ring);
207 	}
208 
209 	return 0;
210 }
211 
212 /**
213  * amdgpu_sync_free - free the sync object
214  *
215  * @adev: amdgpu_device pointer
216  * @sync: sync object to use
217  * @fence: fence to use for the free
218  *
219  * Free the sync object by freeing all semaphores in it.
220  */
221 void amdgpu_sync_free(struct amdgpu_device *adev,
222 		      struct amdgpu_sync *sync,
223 		      struct amdgpu_fence *fence)
224 {
225 	unsigned i;
226 
227 	for (i = 0; i < AMDGPU_NUM_SYNCS; ++i)
228 		amdgpu_semaphore_free(adev, &sync->semaphores[i], fence);
229 
230 	for (i = 0; i < AMDGPU_MAX_RINGS; ++i)
231 		amdgpu_fence_unref(&sync->sync_to[i]);
232 
233 	amdgpu_fence_unref(&sync->last_vm_update);
234 }
235