1 /* 2 * Copyright (C) 2013 Red Hat 3 * 4 * Permission is hereby granted, free of charge, to any person obtaining a 5 * copy of this software and associated documentation files (the "Software"), 6 * to deal in the Software without restriction, including without limitation 7 * the rights to use, copy, modify, merge, publish, distribute, sublicense, 8 * and/or sell copies of the Software, and to permit persons to whom the 9 * Software is furnished to do so, subject to the following conditions: 10 * 11 * The above copyright notice and this permission notice (including the next 12 * paragraph) shall be included in all copies or substantial portions of the 13 * Software. 14 * 15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 20 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE 21 * SOFTWARE. 22 */ 23 24 #include "drmP.h" 25 #include "drm_flip_work.h" 26 27 /** 28 * drm_flip_work_queue - queue work 29 * @work: the flip-work 30 * @val: the value to queue 31 * 32 * Queues work, that will later be run (passed back to drm_flip_func_t 33 * func) on a work queue after drm_flip_work_commit() is called. 34 */ 35 void drm_flip_work_queue(struct drm_flip_work *work, void *val) 36 { 37 if (kfifo_put(&work->fifo, (const void **)&val)) { 38 atomic_inc(&work->pending); 39 } else { 40 DRM_ERROR("%s fifo full!\n", work->name); 41 work->func(work, val); 42 } 43 } 44 EXPORT_SYMBOL(drm_flip_work_queue); 45 46 /** 47 * drm_flip_work_commit - commit queued work 48 * @work: the flip-work 49 * @wq: the work-queue to run the queued work on 50 * 51 * Trigger work previously queued by drm_flip_work_queue() to run 52 * on a workqueue. The typical usage would be to queue work (via 53 * drm_flip_work_queue()) at any point (from vblank irq and/or 54 * prior), and then from vblank irq commit the queued work. 55 */ 56 void drm_flip_work_commit(struct drm_flip_work *work, 57 struct workqueue_struct *wq) 58 { 59 uint32_t pending = atomic_read(&work->pending); 60 atomic_add(pending, &work->count); 61 atomic_sub(pending, &work->pending); 62 queue_work(wq, &work->worker); 63 } 64 EXPORT_SYMBOL(drm_flip_work_commit); 65 66 static void flip_worker(struct work_struct *w) 67 { 68 struct drm_flip_work *work = container_of(w, struct drm_flip_work, worker); 69 uint32_t count = atomic_read(&work->count); 70 void *val = NULL; 71 72 atomic_sub(count, &work->count); 73 74 while(count--) 75 if (!WARN_ON(!kfifo_get(&work->fifo, &val))) 76 work->func(work, val); 77 } 78 79 /** 80 * drm_flip_work_init - initialize flip-work 81 * @work: the flip-work to initialize 82 * @size: the max queue depth 83 * @name: debug name 84 * @func: the callback work function 85 * 86 * Initializes/allocates resources for the flip-work 87 * 88 * RETURNS: 89 * Zero on success, error code on failure. 90 */ 91 int drm_flip_work_init(struct drm_flip_work *work, int size, 92 const char *name, drm_flip_func_t func) 93 { 94 int ret; 95 96 work->name = name; 97 atomic_set(&work->count, 0); 98 atomic_set(&work->pending, 0); 99 work->func = func; 100 101 ret = kfifo_alloc(&work->fifo, size, GFP_KERNEL); 102 if (ret) { 103 DRM_ERROR("could not allocate %s fifo\n", name); 104 return ret; 105 } 106 107 INIT_WORK(&work->worker, flip_worker); 108 109 return 0; 110 } 111 EXPORT_SYMBOL(drm_flip_work_init); 112 113 /** 114 * drm_flip_work_cleanup - cleans up flip-work 115 * @work: the flip-work to cleanup 116 * 117 * Destroy resources allocated for the flip-work 118 */ 119 void drm_flip_work_cleanup(struct drm_flip_work *work) 120 { 121 WARN_ON(!kfifo_is_empty(&work->fifo)); 122 kfifo_free(&work->fifo); 123 } 124 EXPORT_SYMBOL(drm_flip_work_cleanup); 125