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

source code of linux/drivers/gpu/drm/drm_flip_work.c