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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * dma-fence-array: aggregate fences to be waited together
4 *
5 * Copyright (C) 2016 Collabora Ltd
6 * Copyright (C) 2016 Advanced Micro Devices, Inc.
7 * Authors:
8 * Gustavo Padovan <gustavo@padovan.org>
9 * Christian König <christian.koenig@amd.com>
10 */
11
12#include <linux/export.h>
13#include <linux/slab.h>
14#include <linux/dma-fence-array.h>
15
16#define PENDING_ERROR 1
17
18static const char *dma_fence_array_get_driver_name(struct dma_fence *fence)
19{
20 return "dma_fence_array";
21}
22
23static const char *dma_fence_array_get_timeline_name(struct dma_fence *fence)
24{
25 return "unbound";
26}
27
28static void dma_fence_array_set_pending_error(struct dma_fence_array *array,
29 int error)
30{
31 /*
32 * Propagate the first error reported by any of our fences, but only
33 * before we ourselves are signaled.
34 */
35 if (error)
36 cmpxchg(&array->base.error, PENDING_ERROR, error);
37}
38
39static void dma_fence_array_clear_pending_error(struct dma_fence_array *array)
40{
41 /* Clear the error flag if not actually set. */
42 cmpxchg(&array->base.error, PENDING_ERROR, 0);
43}
44
45static void irq_dma_fence_array_work(struct irq_work *wrk)
46{
47 struct dma_fence_array *array = container_of(wrk, typeof(*array), work);
48
49 dma_fence_array_clear_pending_error(array);
50
51 dma_fence_signal(&array->base);
52 dma_fence_put(&array->base);
53}
54
55static void dma_fence_array_cb_func(struct dma_fence *f,
56 struct dma_fence_cb *cb)
57{
58 struct dma_fence_array_cb *array_cb =
59 container_of(cb, struct dma_fence_array_cb, cb);
60 struct dma_fence_array *array = array_cb->array;
61
62 dma_fence_array_set_pending_error(array, f->error);
63
64 if (atomic_dec_and_test(&array->num_pending))
65 irq_work_queue(&array->work);
66 else
67 dma_fence_put(&array->base);
68}
69
70static bool dma_fence_array_enable_signaling(struct dma_fence *fence)
71{
72 struct dma_fence_array *array = to_dma_fence_array(fence);
73 struct dma_fence_array_cb *cb = (void *)(&array[1]);
74 unsigned i;
75
76 for (i = 0; i < array->num_fences; ++i) {
77 cb[i].array = array;
78 /*
79 * As we may report that the fence is signaled before all
80 * callbacks are complete, we need to take an additional
81 * reference count on the array so that we do not free it too
82 * early. The core fence handling will only hold the reference
83 * until we signal the array as complete (but that is now
84 * insufficient).
85 */
86 dma_fence_get(&array->base);
87 if (dma_fence_add_callback(array->fences[i], &cb[i].cb,
88 dma_fence_array_cb_func)) {
89 int error = array->fences[i]->error;
90
91 dma_fence_array_set_pending_error(array, error);
92 dma_fence_put(&array->base);
93 if (atomic_dec_and_test(&array->num_pending)) {
94 dma_fence_array_clear_pending_error(array);
95 return false;
96 }
97 }
98 }
99
100 return true;
101}
102
103static bool dma_fence_array_signaled(struct dma_fence *fence)
104{
105 struct dma_fence_array *array = to_dma_fence_array(fence);
106
107 if (atomic_read(&array->num_pending) > 0)
108 return false;
109
110 dma_fence_array_clear_pending_error(array);
111 return true;
112}
113
114static void dma_fence_array_release(struct dma_fence *fence)
115{
116 struct dma_fence_array *array = to_dma_fence_array(fence);
117 unsigned i;
118
119 for (i = 0; i < array->num_fences; ++i)
120 dma_fence_put(array->fences[i]);
121
122 kfree(array->fences);
123 dma_fence_free(fence);
124}
125
126static void dma_fence_array_set_deadline(struct dma_fence *fence,
127 ktime_t deadline)
128{
129 struct dma_fence_array *array = to_dma_fence_array(fence);
130 unsigned i;
131
132 for (i = 0; i < array->num_fences; ++i)
133 dma_fence_set_deadline(array->fences[i], deadline);
134}
135
136const struct dma_fence_ops dma_fence_array_ops = {
137 .get_driver_name = dma_fence_array_get_driver_name,
138 .get_timeline_name = dma_fence_array_get_timeline_name,
139 .enable_signaling = dma_fence_array_enable_signaling,
140 .signaled = dma_fence_array_signaled,
141 .release = dma_fence_array_release,
142 .set_deadline = dma_fence_array_set_deadline,
143};
144EXPORT_SYMBOL(dma_fence_array_ops);
145
146/**
147 * dma_fence_array_create - Create a custom fence array
148 * @num_fences: [in] number of fences to add in the array
149 * @fences: [in] array containing the fences
150 * @context: [in] fence context to use
151 * @seqno: [in] sequence number to use
152 * @signal_on_any: [in] signal on any fence in the array
153 *
154 * Allocate a dma_fence_array object and initialize the base fence with
155 * dma_fence_init().
156 * In case of error it returns NULL.
157 *
158 * The caller should allocate the fences array with num_fences size
159 * and fill it with the fences it wants to add to the object. Ownership of this
160 * array is taken and dma_fence_put() is used on each fence on release.
161 *
162 * If @signal_on_any is true the fence array signals if any fence in the array
163 * signals, otherwise it signals when all fences in the array signal.
164 */
165struct dma_fence_array *dma_fence_array_create(int num_fences,
166 struct dma_fence **fences,
167 u64 context, unsigned seqno,
168 bool signal_on_any)
169{
170 struct dma_fence_array *array;
171 size_t size = sizeof(*array);
172
173 WARN_ON(!num_fences || !fences);
174
175 /* Allocate the callback structures behind the array. */
176 size += num_fences * sizeof(struct dma_fence_array_cb);
177 array = kzalloc(size, GFP_KERNEL);
178 if (!array)
179 return NULL;
180
181 spin_lock_init(&array->lock);
182 dma_fence_init(&array->base, &dma_fence_array_ops, &array->lock,
183 context, seqno);
184 init_irq_work(&array->work, irq_dma_fence_array_work);
185
186 array->num_fences = num_fences;
187 atomic_set(&array->num_pending, signal_on_any ? 1 : num_fences);
188 array->fences = fences;
189
190 array->base.error = PENDING_ERROR;
191
192 /*
193 * dma_fence_array objects should never contain any other fence
194 * containers or otherwise we run into recursion and potential kernel
195 * stack overflow on operations on the dma_fence_array.
196 *
197 * The correct way of handling this is to flatten out the array by the
198 * caller instead.
199 *
200 * Enforce this here by checking that we don't create a dma_fence_array
201 * with any container inside.
202 */
203 while (num_fences--)
204 WARN_ON(dma_fence_is_container(fences[num_fences]));
205
206 return array;
207}
208EXPORT_SYMBOL(dma_fence_array_create);
209
210/**
211 * dma_fence_match_context - Check if all fences are from the given context
212 * @fence: [in] fence or fence array
213 * @context: [in] fence context to check all fences against
214 *
215 * Checks the provided fence or, for a fence array, all fences in the array
216 * against the given context. Returns false if any fence is from a different
217 * context.
218 */
219bool dma_fence_match_context(struct dma_fence *fence, u64 context)
220{
221 struct dma_fence_array *array = to_dma_fence_array(fence);
222 unsigned i;
223
224 if (!dma_fence_is_array(fence))
225 return fence->context == context;
226
227 for (i = 0; i < array->num_fences; i++) {
228 if (array->fences[i]->context != context)
229 return false;
230 }
231
232 return true;
233}
234EXPORT_SYMBOL(dma_fence_match_context);
235
236struct dma_fence *dma_fence_array_first(struct dma_fence *head)
237{
238 struct dma_fence_array *array;
239
240 if (!head)
241 return NULL;
242
243 array = to_dma_fence_array(head);
244 if (!array)
245 return head;
246
247 if (!array->num_fences)
248 return NULL;
249
250 return array->fences[0];
251}
252EXPORT_SYMBOL(dma_fence_array_first);
253
254struct dma_fence *dma_fence_array_next(struct dma_fence *head,
255 unsigned int index)
256{
257 struct dma_fence_array *array = to_dma_fence_array(head);
258
259 if (!array || index >= array->num_fences)
260 return NULL;
261
262 return array->fences[index];
263}
264EXPORT_SYMBOL(dma_fence_array_next);
1/*
2 * dma-fence-array: aggregate fences to be waited together
3 *
4 * Copyright (C) 2016 Collabora Ltd
5 * Copyright (C) 2016 Advanced Micro Devices, Inc.
6 * Authors:
7 * Gustavo Padovan <gustavo@padovan.org>
8 * Christian König <christian.koenig@amd.com>
9 *
10 * This program is free software; you can redistribute it and/or modify it
11 * under the terms of the GNU General Public License version 2 as published by
12 * the Free Software Foundation.
13 *
14 * This program is distributed in the hope that it will be useful, but WITHOUT
15 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
16 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
17 * more details.
18 */
19
20#include <linux/export.h>
21#include <linux/slab.h>
22#include <linux/dma-fence-array.h>
23
24static const char *dma_fence_array_get_driver_name(struct dma_fence *fence)
25{
26 return "dma_fence_array";
27}
28
29static const char *dma_fence_array_get_timeline_name(struct dma_fence *fence)
30{
31 return "unbound";
32}
33
34static void irq_dma_fence_array_work(struct irq_work *wrk)
35{
36 struct dma_fence_array *array = container_of(wrk, typeof(*array), work);
37
38 dma_fence_signal(&array->base);
39 dma_fence_put(&array->base);
40}
41
42static void dma_fence_array_cb_func(struct dma_fence *f,
43 struct dma_fence_cb *cb)
44{
45 struct dma_fence_array_cb *array_cb =
46 container_of(cb, struct dma_fence_array_cb, cb);
47 struct dma_fence_array *array = array_cb->array;
48
49 if (atomic_dec_and_test(&array->num_pending))
50 irq_work_queue(&array->work);
51 else
52 dma_fence_put(&array->base);
53}
54
55static bool dma_fence_array_enable_signaling(struct dma_fence *fence)
56{
57 struct dma_fence_array *array = to_dma_fence_array(fence);
58 struct dma_fence_array_cb *cb = (void *)(&array[1]);
59 unsigned i;
60
61 for (i = 0; i < array->num_fences; ++i) {
62 cb[i].array = array;
63 /*
64 * As we may report that the fence is signaled before all
65 * callbacks are complete, we need to take an additional
66 * reference count on the array so that we do not free it too
67 * early. The core fence handling will only hold the reference
68 * until we signal the array as complete (but that is now
69 * insufficient).
70 */
71 dma_fence_get(&array->base);
72 if (dma_fence_add_callback(array->fences[i], &cb[i].cb,
73 dma_fence_array_cb_func)) {
74 dma_fence_put(&array->base);
75 if (atomic_dec_and_test(&array->num_pending))
76 return false;
77 }
78 }
79
80 return true;
81}
82
83static bool dma_fence_array_signaled(struct dma_fence *fence)
84{
85 struct dma_fence_array *array = to_dma_fence_array(fence);
86
87 return atomic_read(&array->num_pending) <= 0;
88}
89
90static void dma_fence_array_release(struct dma_fence *fence)
91{
92 struct dma_fence_array *array = to_dma_fence_array(fence);
93 unsigned i;
94
95 for (i = 0; i < array->num_fences; ++i)
96 dma_fence_put(array->fences[i]);
97
98 kfree(array->fences);
99 dma_fence_free(fence);
100}
101
102const struct dma_fence_ops dma_fence_array_ops = {
103 .get_driver_name = dma_fence_array_get_driver_name,
104 .get_timeline_name = dma_fence_array_get_timeline_name,
105 .enable_signaling = dma_fence_array_enable_signaling,
106 .signaled = dma_fence_array_signaled,
107 .wait = dma_fence_default_wait,
108 .release = dma_fence_array_release,
109};
110EXPORT_SYMBOL(dma_fence_array_ops);
111
112/**
113 * dma_fence_array_create - Create a custom fence array
114 * @num_fences: [in] number of fences to add in the array
115 * @fences: [in] array containing the fences
116 * @context: [in] fence context to use
117 * @seqno: [in] sequence number to use
118 * @signal_on_any: [in] signal on any fence in the array
119 *
120 * Allocate a dma_fence_array object and initialize the base fence with
121 * dma_fence_init().
122 * In case of error it returns NULL.
123 *
124 * The caller should allocate the fences array with num_fences size
125 * and fill it with the fences it wants to add to the object. Ownership of this
126 * array is taken and dma_fence_put() is used on each fence on release.
127 *
128 * If @signal_on_any is true the fence array signals if any fence in the array
129 * signals, otherwise it signals when all fences in the array signal.
130 */
131struct dma_fence_array *dma_fence_array_create(int num_fences,
132 struct dma_fence **fences,
133 u64 context, unsigned seqno,
134 bool signal_on_any)
135{
136 struct dma_fence_array *array;
137 size_t size = sizeof(*array);
138
139 /* Allocate the callback structures behind the array. */
140 size += num_fences * sizeof(struct dma_fence_array_cb);
141 array = kzalloc(size, GFP_KERNEL);
142 if (!array)
143 return NULL;
144
145 spin_lock_init(&array->lock);
146 dma_fence_init(&array->base, &dma_fence_array_ops, &array->lock,
147 context, seqno);
148 init_irq_work(&array->work, irq_dma_fence_array_work);
149
150 array->num_fences = num_fences;
151 atomic_set(&array->num_pending, signal_on_any ? 1 : num_fences);
152 array->fences = fences;
153
154 return array;
155}
156EXPORT_SYMBOL(dma_fence_array_create);
157
158/**
159 * dma_fence_match_context - Check if all fences are from the given context
160 * @fence: [in] fence or fence array
161 * @context: [in] fence context to check all fences against
162 *
163 * Checks the provided fence or, for a fence array, all fences in the array
164 * against the given context. Returns false if any fence is from a different
165 * context.
166 */
167bool dma_fence_match_context(struct dma_fence *fence, u64 context)
168{
169 struct dma_fence_array *array = to_dma_fence_array(fence);
170 unsigned i;
171
172 if (!dma_fence_is_array(fence))
173 return fence->context == context;
174
175 for (i = 0; i < array->num_fences; i++) {
176 if (array->fences[i]->context != context)
177 return false;
178 }
179
180 return true;
181}
182EXPORT_SYMBOL(dma_fence_match_context);