xref: /openbmc/linux/drivers/gpu/drm/radeon/radeon_semaphore.c (revision 1a4e39c2e5ca2eb494a53ecd73055562f690bca0)
1 /*
2  * Copyright 2011 Christian König.
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 <deathsimple@vodafone.de>
29  */
30 #include <drm/drmP.h>
31 #include "radeon.h"
32 #include "radeon_trace.h"
33 
34 int radeon_semaphore_create(struct radeon_device *rdev,
35 			    struct radeon_semaphore **semaphore)
36 {
37 	uint64_t *cpu_addr;
38 	int i, r;
39 
40 	*semaphore = kmalloc(sizeof(struct radeon_semaphore), GFP_KERNEL);
41 	if (*semaphore == NULL) {
42 		return -ENOMEM;
43 	}
44 	r = radeon_sa_bo_new(rdev, &rdev->ring_tmp_bo, &(*semaphore)->sa_bo,
45 			     8 * RADEON_NUM_SYNCS, 8);
46 	if (r) {
47 		kfree(*semaphore);
48 		*semaphore = NULL;
49 		return r;
50 	}
51 	(*semaphore)->waiters = 0;
52 	(*semaphore)->gpu_addr = radeon_sa_bo_gpu_addr((*semaphore)->sa_bo);
53 
54 	cpu_addr = radeon_sa_bo_cpu_addr((*semaphore)->sa_bo);
55 	for (i = 0; i < RADEON_NUM_SYNCS; ++i)
56 		cpu_addr[i] = 0;
57 
58 	for (i = 0; i < RADEON_NUM_RINGS; ++i)
59 		(*semaphore)->sync_to[i] = NULL;
60 
61 	return 0;
62 }
63 
64 bool radeon_semaphore_emit_signal(struct radeon_device *rdev, int ridx,
65 			          struct radeon_semaphore *semaphore)
66 {
67 	struct radeon_ring *ring = &rdev->ring[ridx];
68 
69 	trace_radeon_semaphore_signale(ridx, semaphore);
70 
71 	if (radeon_semaphore_ring_emit(rdev, ridx, ring, semaphore, false)) {
72 		--semaphore->waiters;
73 
74 		/* for debugging lockup only, used by sysfs debug files */
75 		ring->last_semaphore_signal_addr = semaphore->gpu_addr;
76 		return true;
77 	}
78 	return false;
79 }
80 
81 bool radeon_semaphore_emit_wait(struct radeon_device *rdev, int ridx,
82 			        struct radeon_semaphore *semaphore)
83 {
84 	struct radeon_ring *ring = &rdev->ring[ridx];
85 
86 	trace_radeon_semaphore_wait(ridx, semaphore);
87 
88 	if (radeon_semaphore_ring_emit(rdev, ridx, ring, semaphore, true)) {
89 		++semaphore->waiters;
90 
91 		/* for debugging lockup only, used by sysfs debug files */
92 		ring->last_semaphore_wait_addr = semaphore->gpu_addr;
93 		return true;
94 	}
95 	return false;
96 }
97 
98 /**
99  * radeon_semaphore_sync_fence - use the semaphore to sync to a fence
100  *
101  * @semaphore: semaphore object to add fence to
102  * @fence: fence to sync to
103  *
104  * Sync to the fence using this semaphore object
105  */
106 void radeon_semaphore_sync_fence(struct radeon_semaphore *semaphore,
107 				 struct radeon_fence *fence)
108 {
109         struct radeon_fence *other;
110 
111         if (!fence)
112                 return;
113 
114         other = semaphore->sync_to[fence->ring];
115         semaphore->sync_to[fence->ring] = radeon_fence_later(fence, other);
116 }
117 
118 /**
119  * radeon_semaphore_sync_to - use the semaphore to sync to a reservation object
120  *
121  * @sema: semaphore object to add fence from reservation object to
122  * @resv: reservation object with embedded fence
123  * @shared: true if we should onyl sync to the exclusive fence
124  *
125  * Sync to the fence using this semaphore object
126  */
127 int radeon_semaphore_sync_resv(struct radeon_device *rdev,
128 			       struct radeon_semaphore *sema,
129 			       struct reservation_object *resv,
130 			       bool shared)
131 {
132 	struct reservation_object_list *flist;
133 	struct fence *f;
134 	struct radeon_fence *fence;
135 	unsigned i;
136 	int r = 0;
137 
138 	/* always sync to the exclusive fence */
139 	f = reservation_object_get_excl(resv);
140 	fence = f ? to_radeon_fence(f) : NULL;
141 	if (fence && fence->rdev == rdev)
142 		radeon_semaphore_sync_fence(sema, fence);
143 	else if (f)
144 		r = fence_wait(f, true);
145 
146 	flist = reservation_object_get_list(resv);
147 	if (shared || !flist || r)
148 		return r;
149 
150 	for (i = 0; i < flist->shared_count; ++i) {
151 		f = rcu_dereference_protected(flist->shared[i],
152 					      reservation_object_held(resv));
153 		fence = to_radeon_fence(f);
154 		if (fence && fence->rdev == rdev)
155 			radeon_semaphore_sync_fence(sema, fence);
156 		else
157 			r = fence_wait(f, true);
158 
159 		if (r)
160 			break;
161 	}
162 	return r;
163 }
164 
165 /**
166  * radeon_semaphore_sync_rings - sync ring to all registered fences
167  *
168  * @rdev: radeon_device pointer
169  * @semaphore: semaphore object to use for sync
170  * @ring: ring that needs sync
171  *
172  * Ensure that all registered fences are signaled before letting
173  * the ring continue. The caller must hold the ring lock.
174  */
175 int radeon_semaphore_sync_rings(struct radeon_device *rdev,
176 				struct radeon_semaphore *semaphore,
177 				int ring)
178 {
179 	unsigned count = 0;
180 	int i, r;
181 
182         for (i = 0; i < RADEON_NUM_RINGS; ++i) {
183 		struct radeon_fence *fence = semaphore->sync_to[i];
184 
185 		/* check if we really need to sync */
186                 if (!radeon_fence_need_sync(fence, ring))
187 			continue;
188 
189 		/* prevent GPU deadlocks */
190 		if (!rdev->ring[i].ready) {
191 			dev_err(rdev->dev, "Syncing to a disabled ring!");
192 			return -EINVAL;
193 		}
194 
195 		if (++count > RADEON_NUM_SYNCS) {
196 			/* not enough room, wait manually */
197 			r = radeon_fence_wait(fence, false);
198 			if (r)
199 				return r;
200 			continue;
201 		}
202 
203 		/* allocate enough space for sync command */
204 		r = radeon_ring_alloc(rdev, &rdev->ring[i], 16);
205 		if (r) {
206 			return r;
207 		}
208 
209 		/* emit the signal semaphore */
210 		if (!radeon_semaphore_emit_signal(rdev, i, semaphore)) {
211 			/* signaling wasn't successful wait manually */
212 			radeon_ring_undo(&rdev->ring[i]);
213 			r = radeon_fence_wait(fence, false);
214 			if (r)
215 				return r;
216 			continue;
217 		}
218 
219 		/* we assume caller has already allocated space on waiters ring */
220 		if (!radeon_semaphore_emit_wait(rdev, ring, semaphore)) {
221 			/* waiting wasn't successful wait manually */
222 			radeon_ring_undo(&rdev->ring[i]);
223 			r = radeon_fence_wait(fence, false);
224 			if (r)
225 				return r;
226 			continue;
227 		}
228 
229 		radeon_ring_commit(rdev, &rdev->ring[i], false);
230 		radeon_fence_note_sync(fence, ring);
231 
232 		semaphore->gpu_addr += 8;
233 	}
234 
235 	return 0;
236 }
237 
238 void radeon_semaphore_free(struct radeon_device *rdev,
239 			   struct radeon_semaphore **semaphore,
240 			   struct radeon_fence *fence)
241 {
242 	if (semaphore == NULL || *semaphore == NULL) {
243 		return;
244 	}
245 	if ((*semaphore)->waiters > 0) {
246 		dev_err(rdev->dev, "semaphore %p has more waiters than signalers,"
247 			" hardware lockup imminent!\n", *semaphore);
248 	}
249 	radeon_sa_bo_free(rdev, &(*semaphore)->sa_bo, fence);
250 	kfree(*semaphore);
251 	*semaphore = NULL;
252 }
253