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 */
42void 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 */
63void 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 */
89int 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 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 = 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 = 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 */
137int 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 */
212void 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