1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
|
/*
* Copyright (c) 2016 Mellanox Technologies Ltd. All rights reserved.
* Copyright (c) 2015 System Fabric Works, Inc. All rights reserved.
*
* This software is available to you under a choice of one of two
* licenses. You may choose to be licensed under the terms of the GNU
* General Public License (GPL) Version 2, available from the file
* COPYING in the main directory of this source tree, or the
* OpenIB.org BSD license below:
*
* Redistribution and use in source and binary forms, with or
* without modification, are permitted provided that the following
* conditions are met:
*
* - Redistributions of source code must retain the above
* copyright notice, this list of conditions and the following
* disclaimer.
*
* - Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following
* disclaimer in the documentation and/or other materials
* provided with the distribution.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
#include <linux/kernel.h>
#include <linux/interrupt.h>
#include <linux/hardirq.h>
#include "rxe_task.h"
int __rxe_do_task(struct rxe_task *task)
{
int ret;
while ((ret = task->func(task->arg)) == 0)
;
task->ret = ret;
return ret;
}
/*
* this locking is due to a potential race where
* a second caller finds the task already running
* but looks just after the last call to func
*/
void rxe_do_task(unsigned long data)
{
int cont;
int ret;
unsigned long flags;
struct rxe_task *task = (struct rxe_task *)data;
spin_lock_irqsave(&task->state_lock, flags);
switch (task->state) {
case TASK_STATE_START:
task->state = TASK_STATE_BUSY;
spin_unlock_irqrestore(&task->state_lock, flags);
break;
case TASK_STATE_BUSY:
task->state = TASK_STATE_ARMED;
/* fall through to */
case TASK_STATE_ARMED:
spin_unlock_irqrestore(&task->state_lock, flags);
return;
default:
spin_unlock_irqrestore(&task->state_lock, flags);
pr_warn("%s failed with bad state %d\n", __func__, task->state);
return;
}
do {
cont = 0;
ret = task->func(task->arg);
spin_lock_irqsave(&task->state_lock, flags);
switch (task->state) {
case TASK_STATE_BUSY:
if (ret)
task->state = TASK_STATE_START;
else
cont = 1;
break;
/* soneone tried to run the task since the last time we called
* func, so we will call one more time regardless of the
* return value
*/
case TASK_STATE_ARMED:
task->state = TASK_STATE_BUSY;
cont = 1;
break;
default:
pr_warn("%s failed with bad state %d\n", __func__,
task->state);
}
spin_unlock_irqrestore(&task->state_lock, flags);
} while (cont);
task->ret = ret;
}
int rxe_init_task(void *obj, struct rxe_task *task,
void *arg, int (*func)(void *), char *name)
{
task->obj = obj;
task->arg = arg;
task->func = func;
snprintf(task->name, sizeof(task->name), "%s", name);
task->destroyed = false;
tasklet_init(&task->tasklet, rxe_do_task, (unsigned long)task);
task->state = TASK_STATE_START;
spin_lock_init(&task->state_lock);
return 0;
}
void rxe_cleanup_task(struct rxe_task *task)
{
unsigned long flags;
bool idle;
/*
* Mark the task, then wait for it to finish. It might be
* running in a non-tasklet (direct call) context.
*/
task->destroyed = true;
do {
spin_lock_irqsave(&task->state_lock, flags);
idle = (task->state == TASK_STATE_START);
spin_unlock_irqrestore(&task->state_lock, flags);
} while (!idle);
tasklet_kill(&task->tasklet);
}
void rxe_run_task(struct rxe_task *task, int sched)
{
if (task->destroyed)
return;
if (sched)
tasklet_schedule(&task->tasklet);
else
rxe_do_task((unsigned long)task);
}
void rxe_disable_task(struct rxe_task *task)
{
tasklet_disable(&task->tasklet);
}
void rxe_enable_task(struct rxe_task *task)
{
tasklet_enable(&task->tasklet);
}
|
