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