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/slab.h>
25
26 #include <drm/drm_flip_work.h>
27 #include <drm/drm_print.h>
28 #include <drm/drm_util.h>
29
30 /**
31 * drm_flip_work_allocate_task - allocate a flip-work task
32 * @data: data associated to the task
33 * @flags: allocator flags
34 *
35 * Allocate a drm_flip_task object and attach private data to it.
36 */
37 struct drm_flip_task *drm_flip_work_allocate_task(void *data, gfp_t flags)
38 {
39 struct drm_flip_task *task;
40
41 task = kzalloc(sizeof(*task), flags);
42 if (task)
43 task->data = data;
44
45 return task;
46 }
47 EXPORT_SYMBOL(drm_flip_work_allocate_task);
48
49 /**
50 * drm_flip_work_queue_task - queue a specific task
51 * @work: the flip-work
52 * @task: the task to handle
53 *
54 * Queues task, that will later be run (passed back to drm_flip_func_t
55 * func) on a work queue after drm_flip_work_commit() is called.
56 */
57 void drm_flip_work_queue_task(struct drm_flip_work *work,
58 struct drm_flip_task *task)
59 {
60 unsigned long flags;
61
62 spin_lock_irqsave(&work->lock, flags);
63 list_add_tail(&task->node, &work->queued);
64 spin_unlock_irqrestore(&work->lock, flags);
65 }
66 EXPORT_SYMBOL(drm_flip_work_queue_task);
67
68 /**
69 * drm_flip_work_queue - queue work
70 * @work: the flip-work
71 * @val: the value to queue
72 *
73 * Queues work, that will later be run (passed back to drm_flip_func_t
74 * func) on a work queue after drm_flip_work_commit() is called.
75 */
76 void drm_flip_work_queue(struct drm_flip_work *work, void *val)
77 {
78 struct drm_flip_task *task;
79
80 task = drm_flip_work_allocate_task(val,
81 drm_can_sleep() ? GFP_KERNEL : GFP_ATOMIC);
82 if (task) {
83 drm_flip_work_queue_task(work, task);
84 } else {
85 DRM_ERROR("%s could not allocate task!\n", work->name);
86 work->func(work, val);
87 }
88 }
89 EXPORT_SYMBOL(drm_flip_work_queue);
90
91 /**
92 * drm_flip_work_commit - commit queued work
93 * @work: the flip-work
94 * @wq: the work-queue to run the queued work on
95 *
96 * Trigger work previously queued by drm_flip_work_queue() to run
97 * on a workqueue. The typical usage would be to queue work (via
98 * drm_flip_work_queue()) at any point (from vblank irq and/or
99 * prior), and then from vblank irq commit the queued work.
100 */
101 void drm_flip_work_commit(struct drm_flip_work *work,
102 struct workqueue_struct *wq)
103 {
104 unsigned long flags;
105
106 spin_lock_irqsave(&work->lock, flags);
107 list_splice_tail(&work->queued, &work->commited);
108 INIT_LIST_HEAD(&work->queued);
109 spin_unlock_irqrestore(&work->lock, flags);
110 queue_work(wq, &work->worker);
111 }
112 EXPORT_SYMBOL(drm_flip_work_commit);
113
114 static void flip_worker(struct work_struct *w)
115 {
116 struct drm_flip_work *work = container_of(w, struct drm_flip_work, worker);
117 struct list_head tasks;
118 unsigned long flags;
119
120 while (1) {
121 struct drm_flip_task *task, *tmp;
122
123 INIT_LIST_HEAD(&tasks);
124 spin_lock_irqsave(&work->lock, flags);
125 list_splice_tail(&work->commited, &tasks);
126 INIT_LIST_HEAD(&work->commited);
127 spin_unlock_irqrestore(&work->lock, flags);
128
129 if (list_empty(&tasks))
130 break;
131
132 list_for_each_entry_safe(task, tmp, &tasks, node) {
133 work->func(work, task->data);
134 kfree(task);
135 }
136 }
137 }
138
139 /**
140 * drm_flip_work_init - initialize flip-work
141 * @work: the flip-work to initialize
142 * @name: debug name
143 * @func: the callback work function
144 *
145 * Initializes/allocates resources for the flip-work
146 */
147 void drm_flip_work_init(struct drm_flip_work *work,
148 const char *name, drm_flip_func_t func)
149 {
150 work->name = name;
151 INIT_LIST_HEAD(&work->queued);
152 INIT_LIST_HEAD(&work->commited);
153 spin_lock_init(&work->lock);
154 work->func = func;
155
156 INIT_WORK(&work->worker, flip_worker);
157 }
158 EXPORT_SYMBOL(drm_flip_work_init);
159
160 /**
161 * drm_flip_work_cleanup - cleans up flip-work
162 * @work: the flip-work to cleanup
163 *
164 * Destroy resources allocated for the flip-work
165 */
166 void drm_flip_work_cleanup(struct drm_flip_work *work)
167 {
168 WARN_ON(!list_empty(&work->queued) || !list_empty(&work->commited));
169 }
170 EXPORT_SYMBOL(drm_flip_work_cleanup);