1 /*
2  * Copyright (c) 2016 Mellanox Technologies Ltd. All rights reserved.
3  * Copyright (c) 2015 System Fabric Works, Inc. All rights reserved.
4  *
5  * This software is available to you under a choice of one of two
6  * licenses.  You may choose to be licensed under the terms of the GNU
7  * General Public License (GPL) Version 2, available from the file
8  * COPYING in the main directory of this source tree, or the
9  * OpenIB.org BSD license below:
10  *
11  *	   Redistribution and use in source and binary forms, with or
12  *	   without modification, are permitted provided that the following
13  *	   conditions are met:
14  *
15  *	- Redistributions of source code must retain the above
16  *	  copyright notice, this list of conditions and the following
17  *	  disclaimer.
18  *
19  *	- Redistributions in binary form must reproduce the above
20  *	  copyright notice, this list of conditions and the following
21  *	  disclaimer in the documentation and/or other materials
22  *	  provided with the distribution.
23  *
24  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
25  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
26  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
27  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
28  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
29  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
30  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
31  * SOFTWARE.
32  */
33 
34 #ifndef RXE_TASK_H
35 #define RXE_TASK_H
36 
37 enum {
38 	TASK_STATE_START	= 0,
39 	TASK_STATE_BUSY		= 1,
40 	TASK_STATE_ARMED	= 2,
41 };
42 
43 /*
44  * data structure to describe a 'task' which is a short
45  * function that returns 0 as long as it needs to be
46  * called again.
47  */
48 struct rxe_task {
49 	void			*obj;
50 	struct tasklet_struct	tasklet;
51 	int			state;
52 	spinlock_t		state_lock; /* spinlock for task state */
53 	void			*arg;
54 	int			(*func)(void *arg);
55 	int			ret;
56 	char			name[16];
57 	bool			destroyed;
58 };
59 
60 /*
61  * init rxe_task structure
62  *	arg  => parameter to pass to fcn
63  *	fcn  => function to call until it returns != 0
64  */
65 int rxe_init_task(void *obj, struct rxe_task *task,
66 		  void *arg, int (*func)(void *), char *name);
67 
68 /* cleanup task */
69 void rxe_cleanup_task(struct rxe_task *task);
70 
71 /*
72  * raw call to func in loop without any checking
73  * can call when tasklets are disabled
74  */
75 int __rxe_do_task(struct rxe_task *task);
76 
77 /*
78  * common function called by any of the main tasklets
79  * If there is any chance that there is additional
80  * work to do someone must reschedule the task before
81  * leaving
82  */
83 void rxe_do_task(unsigned long data);
84 
85 /* run a task, else schedule it to run as a tasklet, The decision
86  * to run or schedule tasklet is based on the parameter sched.
87  */
88 void rxe_run_task(struct rxe_task *task, int sched);
89 
90 /* keep a task from scheduling */
91 void rxe_disable_task(struct rxe_task *task);
92 
93 /* allow task to run */
94 void rxe_enable_task(struct rxe_task *task);
95 
96 #endif /* RXE_TASK_H */
97