1 /*-
2  * Copyright (c) 2010 Isilon Systems, Inc.
3  * Copyright (c) 2010 iX Systems, Inc.
4  * Copyright (c) 2010 Panasas, Inc.
5  * Copyright (c) 2013-2015 Mellanox Technologies, Ltd.
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice unmodified, this list of conditions, and the following
13  *    disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28  *
29  * $FreeBSD$
30  */
31 #ifndef	_LINUX_WORKQUEUE_H_
32 #define	_LINUX_WORKQUEUE_H_
33 
34 #include <linux/types.h>
35 #include <linux/kernel.h>
36 #include <linux/timer.h>
37 #include <linux/slab.h>
38 
39 #include <sys/taskqueue.h>
40 
41 struct workqueue_struct {
42 	struct taskqueue	*taskqueue;
43 };
44 
45 struct work_struct {
46 	struct	task 		work_task;
47 	struct	taskqueue	*taskqueue;
48 	void			(*fn)(struct work_struct *);
49 };
50 
51 typedef __typeof(((struct work_struct *)0)->fn) work_func_t;
52 
53 struct delayed_work {
54 	struct work_struct	work;
55 	struct callout		timer;
56 };
57 
58 extern void linux_work_fn(void *, int);
59 extern void linux_flush_fn(void *, int);
60 extern void linux_delayed_work_fn(void *);
61 extern struct workqueue_struct *linux_create_workqueue_common(const char *, int);
62 extern void destroy_workqueue(struct workqueue_struct *);
63 
64 static inline struct delayed_work *
65 to_delayed_work(struct work_struct *work)
66 {
67 
68  	return container_of(work, struct delayed_work, work);
69 }
70 
71 #define	INIT_WORK(work, func) 	 					\
72 do {									\
73 	(work)->fn = (func);						\
74 	(work)->taskqueue = NULL;					\
75 	TASK_INIT(&(work)->work_task, 0, linux_work_fn, (work));		\
76 } while (0)
77 
78 #define	INIT_DELAYED_WORK(_work, func)					\
79 do {									\
80 	INIT_WORK(&(_work)->work, func);				\
81 	callout_init(&(_work)->timer, 1);				\
82 } while (0)
83 
84 #define	INIT_DEFERRABLE_WORK(...) INIT_DELAYED_WORK(__VA_ARGS__)
85 
86 #define	schedule_work(work)						\
87 do {									\
88 	(work)->taskqueue = taskqueue_thread;				\
89 	taskqueue_enqueue(taskqueue_thread, &(work)->work_task);	\
90 } while (0)
91 
92 #define	flush_scheduled_work()	flush_taskqueue(taskqueue_thread)
93 
94 static inline int
95 queue_work(struct workqueue_struct *wq, struct work_struct *work)
96 {
97 	work->taskqueue = wq->taskqueue;
98 	/* Return opposite value to align with Linux logic */
99 	return (!taskqueue_enqueue(wq->taskqueue, &work->work_task));
100 }
101 
102 static inline int
103 queue_delayed_work(struct workqueue_struct *wq, struct delayed_work *work,
104     unsigned long delay)
105 {
106 	int pending;
107 
108 	pending = work->work.work_task.ta_pending;
109 	work->work.taskqueue = wq->taskqueue;
110 	if (delay != 0)
111 		callout_reset(&work->timer, delay, linux_delayed_work_fn, work);
112 	else
113 		linux_delayed_work_fn((void *)work);
114 
115 	return (!pending);
116 }
117 
118 static inline bool
119 schedule_delayed_work(struct delayed_work *dwork,
120     unsigned long delay)
121 {
122 	struct workqueue_struct wq;
123 
124 	wq.taskqueue = taskqueue_thread;
125 	return (queue_delayed_work(&wq, dwork, delay));
126 }
127 
128 #define	create_singlethread_workqueue(name)				\
129 	linux_create_workqueue_common(name, 1)
130 
131 #define	create_workqueue(name)						\
132 	linux_create_workqueue_common(name, MAXCPU)
133 
134 #define	alloc_ordered_workqueue(name, flags)				\
135 	linux_create_workqueue_common(name, 1)
136 
137 #define	alloc_workqueue(name, flags, max_active)			\
138 	linux_create_workqueue_common(name, max_active)
139 
140 #define	flush_workqueue(wq)	flush_taskqueue((wq)->taskqueue)
141 
142 static inline void
143 flush_taskqueue(struct taskqueue *tq)
144 {
145 	struct task flushtask;
146 
147 	PHOLD(curproc);
148 	TASK_INIT(&flushtask, 0, linux_flush_fn, NULL);
149 	taskqueue_enqueue(tq, &flushtask);
150 	taskqueue_drain(tq, &flushtask);
151 	PRELE(curproc);
152 }
153 
154 static inline int
155 cancel_work_sync(struct work_struct *work)
156 {
157 	if (work->taskqueue &&
158 	    taskqueue_cancel(work->taskqueue, &work->work_task, NULL))
159 		taskqueue_drain(work->taskqueue, &work->work_task);
160 	return 0;
161 }
162 
163 /*
164  * This may leave work running on another CPU as it does on Linux.
165  */
166 static inline int
167 cancel_delayed_work(struct delayed_work *work)
168 {
169 
170 	callout_stop(&work->timer);
171 	if (work->work.taskqueue)
172 		return (taskqueue_cancel(work->work.taskqueue,
173 		    &work->work.work_task, NULL) == 0);
174 	return 0;
175 }
176 
177 static inline int
178 cancel_delayed_work_sync(struct delayed_work *work)
179 {
180 
181         callout_drain(&work->timer);
182         if (work->work.taskqueue &&
183             taskqueue_cancel(work->work.taskqueue, &work->work.work_task, NULL))
184                 taskqueue_drain(work->work.taskqueue, &work->work.work_task);
185         return 0;
186 }
187 
188 static inline bool
189 mod_delayed_work(struct workqueue_struct *wq, struct delayed_work *dwork,
190     unsigned long delay)
191 {
192 	cancel_delayed_work(dwork);
193 	queue_delayed_work(wq, dwork, delay);
194 	return false;
195 }
196 
197 #endif	/* _LINUX_WORKQUEUE_H_ */
198