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 24 static const char *dma_fence_array_get_driver_name(struct dma_fence *fence) 25 { 26 return "dma_fence_array"; 27 } 28 29 static const char *dma_fence_array_get_timeline_name(struct dma_fence *fence) 30 { 31 return "unbound"; 32 } 33 34 static 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 42 static 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 55 static 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 83 static 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 90 static 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 } 101 102 const 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 .release = dma_fence_array_release, 108 }; 109 EXPORT_SYMBOL(dma_fence_array_ops); 110 111 /** 112 * dma_fence_array_create - Create a custom fence array 113 * @num_fences: [in] number of fences to add in the array 114 * @fences: [in] array containing the fences 115 * @context: [in] fence context to use 116 * @seqno: [in] sequence number to use 117 * @signal_on_any: [in] signal on any fence in the array 118 * 119 * Allocate a dma_fence_array object and initialize the base fence with 120 * dma_fence_init(). 121 * In case of error it returns NULL. 122 * 123 * The caller should allocate the fences array with num_fences size 124 * and fill it with the fences it wants to add to the object. Ownership of this 125 * array is taken and dma_fence_put() is used on each fence on release. 126 * 127 * If @signal_on_any is true the fence array signals if any fence in the array 128 * signals, otherwise it signals when all fences in the array signal. 129 */ 130 struct dma_fence_array *dma_fence_array_create(int num_fences, 131 struct dma_fence **fences, 132 u64 context, unsigned seqno, 133 bool signal_on_any) 134 { 135 struct dma_fence_array *array; 136 size_t size = sizeof(*array); 137 138 /* Allocate the callback structures behind the array. */ 139 size += num_fences * sizeof(struct dma_fence_array_cb); 140 array = kzalloc(size, GFP_KERNEL); 141 if (!array) 142 return NULL; 143 144 spin_lock_init(&array->lock); 145 dma_fence_init(&array->base, &dma_fence_array_ops, &array->lock, 146 context, seqno); 147 init_irq_work(&array->work, irq_dma_fence_array_work); 148 149 array->num_fences = num_fences; 150 atomic_set(&array->num_pending, signal_on_any ? 1 : num_fences); 151 array->fences = fences; 152 153 return array; 154 } 155 EXPORT_SYMBOL(dma_fence_array_create); 156 157 /** 158 * dma_fence_match_context - Check if all fences are from the given context 159 * @fence: [in] fence or fence array 160 * @context: [in] fence context to check all fences against 161 * 162 * Checks the provided fence or, for a fence array, all fences in the array 163 * against the given context. Returns false if any fence is from a different 164 * context. 165 */ 166 bool dma_fence_match_context(struct dma_fence *fence, u64 context) 167 { 168 struct dma_fence_array *array = to_dma_fence_array(fence); 169 unsigned i; 170 171 if (!dma_fence_is_array(fence)) 172 return fence->context == context; 173 174 for (i = 0; i < array->num_fences; i++) { 175 if (array->fences[i]->context != context) 176 return false; 177 } 178 179 return true; 180 } 181 EXPORT_SYMBOL(dma_fence_match_context); 182