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 <linux/export.h> 25 #include "drmP.h" 26 #include "drm_flip_work.h" 27 28 /** 29 * drm_flip_work_queue - queue work 30 * @work: the flip-work 31 * @val: the value to queue 32 * 33 * Queues work, that will later be run (passed back to drm_flip_func_t 34 * func) on a work queue after drm_flip_work_commit() is called. 35 */ 36 void drm_flip_work_queue(struct drm_flip_work *work, void *val) 37 { 38 if (kfifo_put(&work->fifo, val)) { 39 atomic_inc(&work->pending); 40 } else { 41 DRM_ERROR("%s fifo full!\n", work->name); 42 work->func(work, val); 43 } 44 } 45 EXPORT_SYMBOL(drm_flip_work_queue); 46 47 /** 48 * drm_flip_work_commit - commit queued work 49 * @work: the flip-work 50 * @wq: the work-queue to run the queued work on 51 * 52 * Trigger work previously queued by drm_flip_work_queue() to run 53 * on a workqueue. The typical usage would be to queue work (via 54 * drm_flip_work_queue()) at any point (from vblank irq and/or 55 * prior), and then from vblank irq commit the queued work. 56 */ 57 void drm_flip_work_commit(struct drm_flip_work *work, 58 struct workqueue_struct *wq) 59 { 60 uint32_t pending = atomic_read(&work->pending); 61 atomic_add(pending, &work->count); 62 atomic_sub(pending, &work->pending); 63 queue_work(wq, &work->worker); 64 } 65 EXPORT_SYMBOL(drm_flip_work_commit); 66 67 static void flip_worker(struct work_struct *w) 68 { 69 struct drm_flip_work *work = container_of(w, struct drm_flip_work, worker); 70 uint32_t count = atomic_read(&work->count); 71 void *val = NULL; 72 73 atomic_sub(count, &work->count); 74 75 while(count--) 76 if (!WARN_ON(!kfifo_get(&work->fifo, &val))) 77 work->func(work, val); 78 } 79 80 /** 81 * drm_flip_work_init - initialize flip-work 82 * @work: the flip-work to initialize 83 * @size: the max queue depth 84 * @name: debug name 85 * @func: the callback work function 86 * 87 * Initializes/allocates resources for the flip-work 88 * 89 * RETURNS: 90 * Zero on success, error code on failure. 91 */ 92 int drm_flip_work_init(struct drm_flip_work *work, int size, 93 const char *name, drm_flip_func_t func) 94 { 95 int ret; 96 97 work->name = name; 98 atomic_set(&work->count, 0); 99 atomic_set(&work->pending, 0); 100 work->func = func; 101 102 ret = kfifo_alloc(&work->fifo, size, GFP_KERNEL); 103 if (ret) { 104 DRM_ERROR("could not allocate %s fifo\n", name); 105 return ret; 106 } 107 108 INIT_WORK(&work->worker, flip_worker); 109 110 return 0; 111 } 112 EXPORT_SYMBOL(drm_flip_work_init); 113 114 /** 115 * drm_flip_work_cleanup - cleans up flip-work 116 * @work: the flip-work to cleanup 117 * 118 * Destroy resources allocated for the flip-work 119 */ 120 void drm_flip_work_cleanup(struct drm_flip_work *work) 121 { 122 WARN_ON(!kfifo_is_empty(&work->fifo)); 123 kfifo_free(&work->fifo); 124 } 125 EXPORT_SYMBOL(drm_flip_work_cleanup); 126