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 */
36void 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}
45EXPORT_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 */
57void 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}
65EXPORT_SYMBOL(drm_flip_work_commit);
66
67static 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 */
92int 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}
112EXPORT_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 */
120void drm_flip_work_cleanup(struct drm_flip_work *work)
121{
122 WARN_ON(!kfifo_is_empty(&work->fifo));
123 kfifo_free(&work->fifo);
124}
125EXPORT_SYMBOL(drm_flip_work_cleanup);
126