1 /* $NetBSD: drm_flip_work.c,v 1.6 2021/12/19 12:32:01 riastradh Exp $ */
2
3 /*
4 * Copyright (C) 2013 Red Hat
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a
7 * copy of this software and associated documentation files (the "Software"),
8 * to deal in the Software without restriction, including without limitation
9 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
10 * and/or sell copies of the Software, and to permit persons to whom the
11 * Software is furnished to do so, subject to the following conditions:
12 *
13 * The above copyright notice and this permission notice (including the next
14 * paragraph) shall be included in all copies or substantial portions of the
15 * Software.
16 *
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
20 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
21 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
22 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
23 * SOFTWARE.
24 */
25
26 #include <sys/cdefs.h>
27 __KERNEL_RCSID(0, "$NetBSD: drm_flip_work.c,v 1.6 2021/12/19 12:32:01 riastradh Exp $");
28
29 #include <linux/slab.h>
30
31 #include <drm/drm_flip_work.h>
32 #include <drm/drm_print.h>
33 #include <drm/drm_util.h>
34
35 /**
36 * drm_flip_work_allocate_task - allocate a flip-work task
37 * @data: data associated to the task
38 * @flags: allocator flags
39 *
40 * Allocate a drm_flip_task object and attach private data to it.
41 */
drm_flip_work_allocate_task(void * data,gfp_t flags)42 struct drm_flip_task *drm_flip_work_allocate_task(void *data, gfp_t flags)
43 {
44 struct drm_flip_task *task;
45
46 task = kzalloc(sizeof(*task), flags);
47 if (task)
48 task->data = data;
49
50 return task;
51 }
52 EXPORT_SYMBOL(drm_flip_work_allocate_task);
53
54 /**
55 * drm_flip_work_queue_task - queue a specific task
56 * @work: the flip-work
57 * @task: the task to handle
58 *
59 * Queues task, that will later be run (passed back to drm_flip_func_t
60 * func) on a work queue after drm_flip_work_commit() is called.
61 */
drm_flip_work_queue_task(struct drm_flip_work * work,struct drm_flip_task * task)62 void drm_flip_work_queue_task(struct drm_flip_work *work,
63 struct drm_flip_task *task)
64 {
65 unsigned long flags;
66
67 spin_lock_irqsave(&work->lock, flags);
68 list_add_tail(&task->node, &work->queued);
69 spin_unlock_irqrestore(&work->lock, flags);
70 }
71 EXPORT_SYMBOL(drm_flip_work_queue_task);
72
73 /**
74 * drm_flip_work_queue - queue work
75 * @work: the flip-work
76 * @val: the value to queue
77 *
78 * Queues work, that will later be run (passed back to drm_flip_func_t
79 * func) on a work queue after drm_flip_work_commit() is called.
80 */
drm_flip_work_queue(struct drm_flip_work * work,void * val)81 void drm_flip_work_queue(struct drm_flip_work *work, void *val)
82 {
83 struct drm_flip_task *task;
84
85 task = drm_flip_work_allocate_task(val,
86 drm_can_sleep() ? GFP_KERNEL : GFP_ATOMIC);
87 if (task) {
88 drm_flip_work_queue_task(work, task);
89 } else {
90 DRM_ERROR("%s could not allocate task!\n", work->name);
91 work->func(work, val);
92 }
93 }
94 EXPORT_SYMBOL(drm_flip_work_queue);
95
96 /**
97 * drm_flip_work_commit - commit queued work
98 * @work: the flip-work
99 * @wq: the work-queue to run the queued work on
100 *
101 * Trigger work previously queued by drm_flip_work_queue() to run
102 * on a workqueue. The typical usage would be to queue work (via
103 * drm_flip_work_queue()) at any point (from vblank irq and/or
104 * prior), and then from vblank irq commit the queued work.
105 */
drm_flip_work_commit(struct drm_flip_work * work,struct workqueue_struct * wq)106 void drm_flip_work_commit(struct drm_flip_work *work,
107 struct workqueue_struct *wq)
108 {
109 unsigned long flags;
110
111 spin_lock_irqsave(&work->lock, flags);
112 list_splice_tail(&work->queued, &work->commited);
113 INIT_LIST_HEAD(&work->queued);
114 spin_unlock_irqrestore(&work->lock, flags);
115 queue_work(wq, &work->worker);
116 }
117 EXPORT_SYMBOL(drm_flip_work_commit);
118
flip_worker(struct work_struct * w)119 static void flip_worker(struct work_struct *w)
120 {
121 struct drm_flip_work *work = container_of(w, struct drm_flip_work, worker);
122 struct list_head tasks;
123 unsigned long flags;
124
125 while (1) {
126 struct drm_flip_task *task, *tmp;
127
128 INIT_LIST_HEAD(&tasks);
129 spin_lock_irqsave(&work->lock, flags);
130 list_splice_tail(&work->commited, &tasks);
131 INIT_LIST_HEAD(&work->commited);
132 spin_unlock_irqrestore(&work->lock, flags);
133
134 if (list_empty(&tasks))
135 break;
136
137 list_for_each_entry_safe(task, tmp, &tasks, node) {
138 work->func(work, task->data);
139 kfree(task);
140 }
141 }
142 }
143
144 /**
145 * drm_flip_work_init - initialize flip-work
146 * @work: the flip-work to initialize
147 * @name: debug name
148 * @func: the callback work function
149 *
150 * Initializes/allocates resources for the flip-work
151 */
drm_flip_work_init(struct drm_flip_work * work,const char * name,drm_flip_func_t func)152 void drm_flip_work_init(struct drm_flip_work *work,
153 const char *name, drm_flip_func_t func)
154 {
155 work->name = name;
156 INIT_LIST_HEAD(&work->queued);
157 INIT_LIST_HEAD(&work->commited);
158 spin_lock_init(&work->lock);
159 work->func = func;
160
161 INIT_WORK(&work->worker, flip_worker);
162 }
163 EXPORT_SYMBOL(drm_flip_work_init);
164
165 /**
166 * drm_flip_work_cleanup - cleans up flip-work
167 * @work: the flip-work to cleanup
168 *
169 * Destroy resources allocated for the flip-work
170 */
drm_flip_work_cleanup(struct drm_flip_work * work)171 void drm_flip_work_cleanup(struct drm_flip_work *work)
172 {
173 WARN_ON(!list_empty(&work->queued) || !list_empty(&work->commited));
174 spin_lock_destroy(&work->lock);
175 }
176 EXPORT_SYMBOL(drm_flip_work_cleanup);
177