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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
126const struct dma_fence_ops dma_fence_array_ops = {
127 .get_driver_name = dma_fence_array_get_driver_name,
128 .get_timeline_name = dma_fence_array_get_timeline_name,
129 .enable_signaling = dma_fence_array_enable_signaling,
130 .signaled = dma_fence_array_signaled,
131 .release = dma_fence_array_release,
132};
133EXPORT_SYMBOL(dma_fence_array_ops);
134
135/**
136 * dma_fence_array_create - Create a custom fence array
137 * @num_fences: [in] number of fences to add in the array
138 * @fences: [in] array containing the fences
139 * @context: [in] fence context to use
140 * @seqno: [in] sequence number to use
141 * @signal_on_any: [in] signal on any fence in the array
142 *
143 * Allocate a dma_fence_array object and initialize the base fence with
144 * dma_fence_init().
145 * In case of error it returns NULL.
146 *
147 * The caller should allocate the fences array with num_fences size
148 * and fill it with the fences it wants to add to the object. Ownership of this
149 * array is taken and dma_fence_put() is used on each fence on release.
150 *
151 * If @signal_on_any is true the fence array signals if any fence in the array
152 * signals, otherwise it signals when all fences in the array signal.
153 */
154struct dma_fence_array *dma_fence_array_create(int num_fences,
155 struct dma_fence **fences,
156 u64 context, unsigned seqno,
157 bool signal_on_any)
158{
159 struct dma_fence_array *array;
160 size_t size = sizeof(*array);
161
162 WARN_ON(!num_fences || !fences);
163
164 /* Allocate the callback structures behind the array. */
165 size += num_fences * sizeof(struct dma_fence_array_cb);
166 array = kzalloc(size, GFP_KERNEL);
167 if (!array)
168 return NULL;
169
170 spin_lock_init(&array->lock);
171 dma_fence_init(&array->base, &dma_fence_array_ops, &array->lock,
172 context, seqno);
173 init_irq_work(&array->work, irq_dma_fence_array_work);
174
175 array->num_fences = num_fences;
176 atomic_set(&array->num_pending, signal_on_any ? 1 : num_fences);
177 array->fences = fences;
178
179 array->base.error = PENDING_ERROR;
180
181 /*
182 * dma_fence_array objects should never contain any other fence
183 * containers or otherwise we run into recursion and potential kernel
184 * stack overflow on operations on the dma_fence_array.
185 *
186 * The correct way of handling this is to flatten out the array by the
187 * caller instead.
188 *
189 * Enforce this here by checking that we don't create a dma_fence_array
190 * with any container inside.
191 */
192 while (num_fences--)
193 WARN_ON(dma_fence_is_container(fences[num_fences]));
194
195 return array;
196}
197EXPORT_SYMBOL(dma_fence_array_create);
198
199/**
200 * dma_fence_match_context - Check if all fences are from the given context
201 * @fence: [in] fence or fence array
202 * @context: [in] fence context to check all fences against
203 *
204 * Checks the provided fence or, for a fence array, all fences in the array
205 * against the given context. Returns false if any fence is from a different
206 * context.
207 */
208bool dma_fence_match_context(struct dma_fence *fence, u64 context)
209{
210 struct dma_fence_array *array = to_dma_fence_array(fence);
211 unsigned i;
212
213 if (!dma_fence_is_array(fence))
214 return fence->context == context;
215
216 for (i = 0; i < array->num_fences; i++) {
217 if (array->fences[i]->context != context)
218 return false;
219 }
220
221 return true;
222}
223EXPORT_SYMBOL(dma_fence_match_context);
224
225struct dma_fence *dma_fence_array_first(struct dma_fence *head)
226{
227 struct dma_fence_array *array;
228
229 if (!head)
230 return NULL;
231
232 array = to_dma_fence_array(head);
233 if (!array)
234 return head;
235
236 if (!array->num_fences)
237 return NULL;
238
239 return array->fences[0];
240}
241EXPORT_SYMBOL(dma_fence_array_first);
242
243struct dma_fence *dma_fence_array_next(struct dma_fence *head,
244 unsigned int index)
245{
246 struct dma_fence_array *array = to_dma_fence_array(head);
247
248 if (!array || index >= array->num_fences)
249 return NULL;
250
251 return array->fences[index];
252}
253EXPORT_SYMBOL(dma_fence_array_next);
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 return atomic_read(&array->num_pending) <= 0;
108}
109
110static void dma_fence_array_release(struct dma_fence *fence)
111{
112 struct dma_fence_array *array = to_dma_fence_array(fence);
113 unsigned i;
114
115 for (i = 0; i < array->num_fences; ++i)
116 dma_fence_put(array->fences[i]);
117
118 kfree(array->fences);
119 dma_fence_free(fence);
120}
121
122const struct dma_fence_ops dma_fence_array_ops = {
123 .get_driver_name = dma_fence_array_get_driver_name,
124 .get_timeline_name = dma_fence_array_get_timeline_name,
125 .enable_signaling = dma_fence_array_enable_signaling,
126 .signaled = dma_fence_array_signaled,
127 .release = dma_fence_array_release,
128};
129EXPORT_SYMBOL(dma_fence_array_ops);
130
131/**
132 * dma_fence_array_create - Create a custom fence array
133 * @num_fences: [in] number of fences to add in the array
134 * @fences: [in] array containing the fences
135 * @context: [in] fence context to use
136 * @seqno: [in] sequence number to use
137 * @signal_on_any: [in] signal on any fence in the array
138 *
139 * Allocate a dma_fence_array object and initialize the base fence with
140 * dma_fence_init().
141 * In case of error it returns NULL.
142 *
143 * The caller should allocate the fences array with num_fences size
144 * and fill it with the fences it wants to add to the object. Ownership of this
145 * array is taken and dma_fence_put() is used on each fence on release.
146 *
147 * If @signal_on_any is true the fence array signals if any fence in the array
148 * signals, otherwise it signals when all fences in the array signal.
149 */
150struct dma_fence_array *dma_fence_array_create(int num_fences,
151 struct dma_fence **fences,
152 u64 context, unsigned seqno,
153 bool signal_on_any)
154{
155 struct dma_fence_array *array;
156 size_t size = sizeof(*array);
157
158 /* Allocate the callback structures behind the array. */
159 size += num_fences * sizeof(struct dma_fence_array_cb);
160 array = kzalloc(size, GFP_KERNEL);
161 if (!array)
162 return NULL;
163
164 spin_lock_init(&array->lock);
165 dma_fence_init(&array->base, &dma_fence_array_ops, &array->lock,
166 context, seqno);
167 init_irq_work(&array->work, irq_dma_fence_array_work);
168
169 array->num_fences = num_fences;
170 atomic_set(&array->num_pending, signal_on_any ? 1 : num_fences);
171 array->fences = fences;
172
173 array->base.error = PENDING_ERROR;
174
175 return array;
176}
177EXPORT_SYMBOL(dma_fence_array_create);
178
179/**
180 * dma_fence_match_context - Check if all fences are from the given context
181 * @fence: [in] fence or fence array
182 * @context: [in] fence context to check all fences against
183 *
184 * Checks the provided fence or, for a fence array, all fences in the array
185 * against the given context. Returns false if any fence is from a different
186 * context.
187 */
188bool dma_fence_match_context(struct dma_fence *fence, u64 context)
189{
190 struct dma_fence_array *array = to_dma_fence_array(fence);
191 unsigned i;
192
193 if (!dma_fence_is_array(fence))
194 return fence->context == context;
195
196 for (i = 0; i < array->num_fences; i++) {
197 if (array->fences[i]->context != context)
198 return false;
199 }
200
201 return true;
202}
203EXPORT_SYMBOL(dma_fence_match_context);