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 static struct kmem_cache *amdgpu_sync_slab;
41 
42 /**
43  * amdgpu_sync_create - zero init sync object
44  *
45  * @sync: sync object to initialize
46  *
47  * Just clear the sync object for now.
48  */
49 void amdgpu_sync_create(struct amdgpu_sync *sync)
50 {
51 	hash_init(sync->fences);
52 	sync->last_vm_update = NULL;
53 }
54 
55 /**
56  * amdgpu_sync_same_dev - test if fence belong to us
57  *
58  * @adev: amdgpu device to use for the test
59  * @f: fence to test
60  *
61  * Test if the fence was issued by us.
62  */
63 static bool amdgpu_sync_same_dev(struct amdgpu_device *adev, struct fence *f)
64 {
65 	struct amd_sched_fence *s_fence = to_amd_sched_fence(f);
66 
67 	if (s_fence) {
68 		struct amdgpu_ring *ring;
69 
70 		ring = container_of(s_fence->sched, struct amdgpu_ring, sched);
71 		return ring->adev == adev;
72 	}
73 
74 	return false;
75 }
76 
77 /**
78  * amdgpu_sync_get_owner - extract the owner of a fence
79  *
80  * @fence: fence get the owner from
81  *
82  * Extract who originally created the fence.
83  */
84 static void *amdgpu_sync_get_owner(struct fence *f)
85 {
86 	struct amd_sched_fence *s_fence = to_amd_sched_fence(f);
87 
88 	if (s_fence)
89 		return s_fence->owner;
90 
91 	return AMDGPU_FENCE_OWNER_UNDEFINED;
92 }
93 
94 /**
95  * amdgpu_sync_keep_later - Keep the later fence
96  *
97  * @keep: existing fence to test
98  * @fence: new fence
99  *
100  * Either keep the existing fence or the new one, depending which one is later.
101  */
102 static void amdgpu_sync_keep_later(struct fence **keep, struct fence *fence)
103 {
104 	if (*keep && fence_is_later(*keep, fence))
105 		return;
106 
107 	fence_put(*keep);
108 	*keep = fence_get(fence);
109 }
110 
111 /**
112  * amdgpu_sync_fence - remember to sync to this fence
113  *
114  * @sync: sync object to add fence to
115  * @fence: fence to sync to
116  *
117  */
118 int amdgpu_sync_fence(struct amdgpu_device *adev, struct amdgpu_sync *sync,
119 		      struct fence *f)
120 {
121 	struct amdgpu_sync_entry *e;
122 
123 	if (!f)
124 		return 0;
125 
126 	if (amdgpu_sync_same_dev(adev, f) &&
127 	    amdgpu_sync_get_owner(f) == AMDGPU_FENCE_OWNER_VM)
128 		amdgpu_sync_keep_later(&sync->last_vm_update, f);
129 
130 	hash_for_each_possible(sync->fences, e, node, f->context) {
131 		if (unlikely(e->fence->context != f->context))
132 			continue;
133 
134 		amdgpu_sync_keep_later(&e->fence, f);
135 		return 0;
136 	}
137 
138 	e = kmem_cache_alloc(amdgpu_sync_slab, GFP_KERNEL);
139 	if (!e)
140 		return -ENOMEM;
141 
142 	hash_add(sync->fences, &e->node, f->context);
143 	e->fence = fence_get(f);
144 	return 0;
145 }
146 
147 /**
148  * amdgpu_sync_resv - sync to a reservation object
149  *
150  * @sync: sync object to add fences from reservation object to
151  * @resv: reservation object with embedded fence
152  * @shared: true if we should only sync to the exclusive fence
153  *
154  * Sync to the fence
155  */
156 int amdgpu_sync_resv(struct amdgpu_device *adev,
157 		     struct amdgpu_sync *sync,
158 		     struct reservation_object *resv,
159 		     void *owner)
160 {
161 	struct reservation_object_list *flist;
162 	struct fence *f;
163 	void *fence_owner;
164 	unsigned i;
165 	int r = 0;
166 
167 	if (resv == NULL)
168 		return -EINVAL;
169 
170 	/* always sync to the exclusive fence */
171 	f = reservation_object_get_excl(resv);
172 	r = amdgpu_sync_fence(adev, sync, f);
173 
174 	flist = reservation_object_get_list(resv);
175 	if (!flist || r)
176 		return r;
177 
178 	for (i = 0; i < flist->shared_count; ++i) {
179 		f = rcu_dereference_protected(flist->shared[i],
180 					      reservation_object_held(resv));
181 		if (amdgpu_sync_same_dev(adev, f)) {
182 			/* VM updates are only interesting
183 			 * for other VM updates and moves.
184 			 */
185 			fence_owner = amdgpu_sync_get_owner(f);
186 			if ((owner != AMDGPU_FENCE_OWNER_UNDEFINED) &&
187 			    (fence_owner != AMDGPU_FENCE_OWNER_UNDEFINED) &&
188 			    ((owner == AMDGPU_FENCE_OWNER_VM) !=
189 			     (fence_owner == AMDGPU_FENCE_OWNER_VM)))
190 				continue;
191 
192 			/* Ignore fence from the same owner as
193 			 * long as it isn't undefined.
194 			 */
195 			if (owner != AMDGPU_FENCE_OWNER_UNDEFINED &&
196 			    fence_owner == owner)
197 				continue;
198 		}
199 
200 		r = amdgpu_sync_fence(adev, sync, f);
201 		if (r)
202 			break;
203 	}
204 	return r;
205 }
206 
207 struct fence *amdgpu_sync_get_fence(struct amdgpu_sync *sync)
208 {
209 	struct amdgpu_sync_entry *e;
210 	struct hlist_node *tmp;
211 	struct fence *f;
212 	int i;
213 
214 	hash_for_each_safe(sync->fences, i, tmp, e, node) {
215 
216 		f = e->fence;
217 
218 		hash_del(&e->node);
219 		kmem_cache_free(amdgpu_sync_slab, e);
220 
221 		if (!fence_is_signaled(f))
222 			return f;
223 
224 		fence_put(f);
225 	}
226 	return NULL;
227 }
228 
229 int amdgpu_sync_wait(struct amdgpu_sync *sync)
230 {
231 	struct amdgpu_sync_entry *e;
232 	struct hlist_node *tmp;
233 	int i, r;
234 
235 	hash_for_each_safe(sync->fences, i, tmp, e, node) {
236 		r = fence_wait(e->fence, false);
237 		if (r)
238 			return r;
239 
240 		hash_del(&e->node);
241 		fence_put(e->fence);
242 		kmem_cache_free(amdgpu_sync_slab, e);
243 	}
244 
245 	return 0;
246 }
247 
248 /**
249  * amdgpu_sync_free - free the sync object
250  *
251  * @sync: sync object to use
252  *
253  * Free the sync object.
254  */
255 void amdgpu_sync_free(struct amdgpu_sync *sync)
256 {
257 	struct amdgpu_sync_entry *e;
258 	struct hlist_node *tmp;
259 	unsigned i;
260 
261 	hash_for_each_safe(sync->fences, i, tmp, e, node) {
262 		hash_del(&e->node);
263 		fence_put(e->fence);
264 		kmem_cache_free(amdgpu_sync_slab, e);
265 	}
266 
267 	fence_put(sync->last_vm_update);
268 }
269 
270 /**
271  * amdgpu_sync_init - init sync object subsystem
272  *
273  * Allocate the slab allocator.
274  */
275 int amdgpu_sync_init(void)
276 {
277 	amdgpu_sync_slab = kmem_cache_create(
278 		"amdgpu_sync", sizeof(struct amdgpu_sync_entry), 0,
279 		SLAB_HWCACHE_ALIGN, NULL);
280 	if (!amdgpu_sync_slab)
281 		return -ENOMEM;
282 
283 	return 0;
284 }
285 
286 /**
287  * amdgpu_sync_fini - fini sync object subsystem
288  *
289  * Free the slab allocator.
290  */
291 void amdgpu_sync_fini(void)
292 {
293 	kmem_cache_destroy(amdgpu_sync_slab);
294 }
295