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
174
175
176
177
178
|
/*
* Copyright (c) 1996-1999 The University of Utah and the Flux Group.
*
* This file is part of the OSKit Linux Glue Libraries, which are free
* software, also known as "open source;" you can redistribute them and/or
* modify them under the terms of the GNU General Public License (GPL),
* version 2, as published by the Free Software Foundation (FSF).
*
* The OSKit is distributed in the hope that it will be useful, but WITHOUT ANY
* WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
* FOR A PARTICULAR PURPOSE. See the GPL for more details. You should have
* received a copy of the GPL along with the OSKit; see the file COPYING. If
* not, write to the FSF, 59 Temple Place #330, Boston, MA 02111-1307, USA.
*/
/*
* Linux scheduler support.
*
* NOTE: These routines must carefully preserve the
* caller's interrupt flag.
*/
#include <linux/sched.h>
#include <asm/atomic.h>
#include "osenv.h"
/*
* Read the discussion in the linux source. Should the spinlock be under SMP?
*/
spinlock_t semaphore_wake_lock = SPIN_LOCK_UNLOCKED;
void
__down(struct semaphore *sem)
{
struct task_struct *cur = current;
struct wait_queue wait = { cur, NULL };
unsigned long flags;
save_flags(flags);
cli();
__add_wait_queue(&sem->wait, &wait);
while (1) {
spin_lock(&semaphore_wake_lock);
if (sem->waking > 0) {
sem->waking--;
spin_unlock(&semaphore_wake_lock);
break;
}
spin_unlock(&semaphore_wake_lock);
osenv_sleep_init(&cur->sleeprec);
osenv_sleep(&cur->sleeprec);
}
__remove_wait_queue(&sem->wait, &wait);
current = cur;
restore_flags(flags);
}
void
__up(struct semaphore *sem)
{
unsigned long flags;
save_flags(flags);
cli();
spin_lock(&semaphore_wake_lock);
if (atomic_read(&sem->count) <= 0)
sem->waking++;
spin_unlock(&semaphore_wake_lock);
restore_flags(flags);
wake_up(&sem->wait);
}
static void
__sleep_on(struct wait_queue **q, int interruptible)
{
struct task_struct *cur = current;
struct wait_queue wait = { cur, NULL };
if (!q)
return;
osenv_sleep_init(&cur->sleeprec);
add_wait_queue(q, &wait);
osenv_sleep(&cur->sleeprec);
current = cur;
remove_wait_queue(q, &wait);
current = cur;
}
void
sleep_on(struct wait_queue **q)
{
__sleep_on(q, 0);
}
void
interruptible_sleep_on(struct wait_queue **q)
{
__sleep_on(q, 1);
}
void
__wake_up(struct wait_queue **q, unsigned int mode)
{
struct wait_queue *next;
struct wait_queue *head;
if (!q || !(next = *q))
return;
head = WAIT_QUEUE_HEAD(q);
while (next != head) {
struct task_struct *p = next->task;
next = next->next;
if (p != NULL) {
osenv_wakeup(&p->sleeprec, OSENV_SLEEP_WAKEUP);
}
if (!next)
panic("wait_queue is bad");
}
}
void
__wait_on_buffer(struct buffer_head *bh)
{
struct task_struct *cur = current;
struct wait_queue wait = { cur, NULL };
unsigned flags;
flags = linux_save_flags();
linux_cli();
__add_wait_queue(&bh->b_wait, &wait);
while (buffer_locked(bh)) {
osenv_sleep_init(&cur->sleeprec);
osenv_sleep(&cur->sleeprec);
}
current = cur;
__remove_wait_queue(&bh->b_wait, &wait);
linux_restore_flags(flags);
current = cur;
}
void
unlock_buffer(struct buffer_head *bh)
{
clear_bit (BH_Lock, &bh->b_state);
wake_up(&bh->b_wait);
}
/*
* schedule() should never be called in the oskit since we have
* no resource contention.
*/
void
schedule()
{
panic("SCHEDULE CALLED!\n");
}
|
