1 /* 2 * Copyright (c) 2019 François Tigeot <ftigeot@wolfpond.org> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice unmodified, this list of conditions, and the following 10 * disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 25 */ 26 27 #include <linux/export.h> 28 #include <linux/slab.h> 29 #include <linux/dma-fence-array.h> 30 31 #define PENDING_ERROR 1 32 33 34 static const char *dma_fence_array_get_driver_name(struct dma_fence *fence) 35 { 36 return "dma_fence_array"; 37 } 38 39 static const char *dma_fence_array_get_timeline_name(struct dma_fence *fence) 40 { 41 return "unbound"; 42 } 43 44 static void dma_fence_array_set_pending_error(struct dma_fence_array *array, 45 int error) 46 { 47 /* 48 * Propagate the first error reported by any of our fences, but only 49 * before we ourselves are signaled. 50 */ 51 if (error) 52 cmpxchg(&array->base.error, PENDING_ERROR, error); 53 } 54 55 static void dma_fence_array_clear_pending_error(struct dma_fence_array *array) 56 { 57 /* Clear the error flag if not actually set. */ 58 cmpxchg(&array->base.error, PENDING_ERROR, 0); 59 } 60 61 static void irq_dma_fence_array_work(struct irq_work *wrk) 62 { 63 struct dma_fence_array *array = container_of(wrk, typeof(*array), work); 64 65 dma_fence_array_clear_pending_error(array); 66 67 dma_fence_signal(&array->base); 68 dma_fence_put(&array->base); 69 } 70 71 static void dma_fence_array_cb_func(struct dma_fence *f, 72 struct dma_fence_cb *cb) 73 { 74 struct dma_fence_array_cb *array_cb = 75 container_of(cb, struct dma_fence_array_cb, cb); 76 struct dma_fence_array *array = array_cb->array; 77 78 dma_fence_array_set_pending_error(array, f->error); 79 80 if (atomic_dec_and_test(&array->num_pending)) 81 irq_work_queue(&array->work); 82 else 83 dma_fence_put(&array->base); 84 } 85 86 static bool dma_fence_array_enable_signaling(struct dma_fence *fence) 87 { 88 struct dma_fence_array *array = to_dma_fence_array(fence); 89 struct dma_fence_array_cb *cb = (void *)(&array[1]); 90 unsigned i; 91 92 for (i = 0; i < array->num_fences; ++i) { 93 cb[i].array = array; 94 /* 95 * As we may report that the fence is signaled before all 96 * callbacks are complete, we need to take an additional 97 * reference count on the array so that we do not free it too 98 * early. The core fence handling will only hold the reference 99 * until we signal the array as complete (but that is now 100 * insufficient). 101 */ 102 dma_fence_get(&array->base); 103 if (dma_fence_add_callback(array->fences[i], &cb[i].cb, 104 dma_fence_array_cb_func)) { 105 int error = array->fences[i]->error; 106 107 dma_fence_array_set_pending_error(array, error); 108 dma_fence_put(&array->base); 109 if (atomic_dec_and_test(&array->num_pending)) { 110 dma_fence_array_clear_pending_error(array); 111 return false; 112 } 113 } 114 } 115 116 return true; 117 } 118 119 static bool dma_fence_array_signaled(struct dma_fence *fence) 120 { 121 struct dma_fence_array *array = to_dma_fence_array(fence); 122 123 return atomic_read(&array->num_pending) <= 0; 124 } 125 126 static void dma_fence_array_release(struct dma_fence *fence) 127 { 128 struct dma_fence_array *array = to_dma_fence_array(fence); 129 unsigned i; 130 131 for (i = 0; i < array->num_fences; ++i) 132 dma_fence_put(array->fences[i]); 133 134 kfree(array->fences); 135 dma_fence_free(fence); 136 } 137 138 const struct dma_fence_ops dma_fence_array_ops = { 139 .get_driver_name = dma_fence_array_get_driver_name, 140 .get_timeline_name = dma_fence_array_get_timeline_name, 141 .enable_signaling = dma_fence_array_enable_signaling, 142 .signaled = dma_fence_array_signaled, 143 .wait = dma_fence_default_wait, 144 .release = dma_fence_array_release, 145 }; 146 EXPORT_SYMBOL(dma_fence_array_ops); 147 148 /** 149 * dma_fence_array_create - Create a custom fence array 150 * @num_fences: [in] number of fences to add in the array 151 * @fences: [in] array containing the fences 152 * @context: [in] fence context to use 153 * @seqno: [in] sequence number to use 154 * @signal_on_any: [in] signal on any fence in the array 155 * 156 * Allocate a dma_fence_array object and initialize the base fence with 157 * dma_fence_init(). 158 * In case of error it returns NULL. 159 * 160 * The caller should allocate the fences array with num_fences size 161 * and fill it with the fences it wants to add to the object. Ownership of this 162 * array is taken and dma_fence_put() is used on each fence on release. 163 * 164 * If @signal_on_any is true the fence array signals if any fence in the array 165 * signals, otherwise it signals when all fences in the array signal. 166 */ 167 struct dma_fence_array *dma_fence_array_create(int num_fences, 168 struct dma_fence **fences, 169 u64 context, unsigned seqno, 170 bool signal_on_any) 171 { 172 struct dma_fence_array *array; 173 size_t size = sizeof(*array); 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 lockinit(&array->lock, "ldmbfal", 0, 0); 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 return array; 193 } 194 EXPORT_SYMBOL(dma_fence_array_create); 195