5113f6f70
김현기
kernel add
|
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
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
|
/***********************license start***************
* Author: Cavium Networks
*
* Contact: support@caviumnetworks.com
* This file is part of the OCTEON SDK
*
* Copyright (c) 2003-2008 Cavium Networks
*
* This file is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License, Version 2, as
* published by the Free Software Foundation.
*
* This file is distributed in the hope that it will be useful, but
* AS-IS and WITHOUT ANY WARRANTY; without even the implied warranty
* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE, TITLE, or
* NONINFRINGEMENT. See the GNU General Public License for more
* details.
*
* You should have received a copy of the GNU General Public License
* along with this file; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
* or visit http://www.gnu.org/licenses/.
*
* This file may also be available under a different license from Cavium.
* Contact Cavium Networks for more information
***********************license end**************************************/
/**
* Implementation of spinlocks for Octeon CVMX. Although similar in
* function to Linux kernel spinlocks, they are not compatible.
* Octeon CVMX spinlocks are only used to synchronize with the boot
* monitor and other non-Linux programs running in the system.
*/
#ifndef __CVMX_SPINLOCK_H__
#define __CVMX_SPINLOCK_H__
#include <asm/octeon/cvmx-asm.h>
/* Spinlocks for Octeon */
/* define these to enable recursive spinlock debugging */
/*#define CVMX_SPINLOCK_DEBUG */
/**
* Spinlocks for Octeon CVMX
*/
typedef struct {
volatile uint32_t value;
} cvmx_spinlock_t;
/* note - macros not expanded in inline ASM, so values hardcoded */
#define CVMX_SPINLOCK_UNLOCKED_VAL 0
#define CVMX_SPINLOCK_LOCKED_VAL 1
#define CVMX_SPINLOCK_UNLOCKED_INITIALIZER {CVMX_SPINLOCK_UNLOCKED_VAL}
/**
* Initialize a spinlock
*
* @lock: Lock to initialize
*/
static inline void cvmx_spinlock_init(cvmx_spinlock_t *lock)
{
lock->value = CVMX_SPINLOCK_UNLOCKED_VAL;
}
/**
* Return non-zero if the spinlock is currently locked
*
* @lock: Lock to check
* Returns Non-zero if locked
*/
static inline int cvmx_spinlock_locked(cvmx_spinlock_t *lock)
{
return lock->value != CVMX_SPINLOCK_UNLOCKED_VAL;
}
/**
* Releases lock
*
* @lock: pointer to lock structure
*/
static inline void cvmx_spinlock_unlock(cvmx_spinlock_t *lock)
{
CVMX_SYNCWS;
lock->value = 0;
CVMX_SYNCWS;
}
/**
* Attempts to take the lock, but does not spin if lock is not available.
* May take some time to acquire the lock even if it is available
* due to the ll/sc not succeeding.
*
* @lock: pointer to lock structure
*
* Returns 0: lock successfully taken
* 1: lock not taken, held by someone else
* These return values match the Linux semantics.
*/
static inline unsigned int cvmx_spinlock_trylock(cvmx_spinlock_t *lock)
{
unsigned int tmp;
__asm__ __volatile__(".set noreorder
"
"1: ll %[tmp], %[val]
"
/* if lock held, fail immediately */
" bnez %[tmp], 2f
"
" li %[tmp], 1
"
" sc %[tmp], %[val]
"
" beqz %[tmp], 1b
"
" li %[tmp], 0
"
"2:
"
".set reorder
" :
[val] "+m"(lock->value), [tmp] "=&r"(tmp)
: : "memory");
return tmp != 0; /* normalize to 0 or 1 */
}
/**
* Gets lock, spins until lock is taken
*
* @lock: pointer to lock structure
*/
static inline void cvmx_spinlock_lock(cvmx_spinlock_t *lock)
{
unsigned int tmp;
__asm__ __volatile__(".set noreorder
"
"1: ll %[tmp], %[val]
"
" bnez %[tmp], 1b
"
" li %[tmp], 1
"
" sc %[tmp], %[val]
"
" beqz %[tmp], 1b
"
" nop
"
".set reorder
" :
[val] "+m"(lock->value), [tmp] "=&r"(tmp)
: : "memory");
}
/** ********************************************************************
* Bit spinlocks
* These spinlocks use a single bit (bit 31) of a 32 bit word for locking.
* The rest of the bits in the word are left undisturbed. This enables more
* compact data structures as only 1 bit is consumed for the lock.
*
*/
/**
* Gets lock, spins until lock is taken
* Preserves the low 31 bits of the 32 bit
* word used for the lock.
*
*
* @word: word to lock bit 31 of
*/
static inline void cvmx_spinlock_bit_lock(uint32_t *word)
{
unsigned int tmp;
unsigned int sav;
__asm__ __volatile__(".set noreorder
"
".set noat
"
"1: ll %[tmp], %[val]
"
" bbit1 %[tmp], 31, 1b
"
" li $at, 1
"
" ins %[tmp], $at, 31, 1
"
" sc %[tmp], %[val]
"
" beqz %[tmp], 1b
"
" nop
"
".set at
"
".set reorder
" :
[val] "+m"(*word), [tmp] "=&r"(tmp), [sav] "=&r"(sav)
: : "memory");
}
/**
* Attempts to get lock, returns immediately with success/failure
* Preserves the low 31 bits of the 32 bit
* word used for the lock.
*
*
* @word: word to lock bit 31 of
* Returns 0: lock successfully taken
* 1: lock not taken, held by someone else
* These return values match the Linux semantics.
*/
static inline unsigned int cvmx_spinlock_bit_trylock(uint32_t *word)
{
unsigned int tmp;
__asm__ __volatile__(".set noreorder
\t"
".set noat
"
"1: ll %[tmp], %[val]
"
/* if lock held, fail immediately */
" bbit1 %[tmp], 31, 2f
"
" li $at, 1
"
" ins %[tmp], $at, 31, 1
"
" sc %[tmp], %[val]
"
" beqz %[tmp], 1b
"
" li %[tmp], 0
"
"2:
"
".set at
"
".set reorder
" :
[val] "+m"(*word), [tmp] "=&r"(tmp)
: : "memory");
return tmp != 0; /* normalize to 0 or 1 */
}
/**
* Releases bit lock
*
* Unconditionally clears bit 31 of the lock word. Note that this is
* done non-atomically, as this implementation assumes that the rest
* of the bits in the word are protected by the lock.
*
* @word: word to unlock bit 31 in
*/
static inline void cvmx_spinlock_bit_unlock(uint32_t *word)
{
CVMX_SYNCWS;
*word &= ~(1UL << 31);
CVMX_SYNCWS;
}
#endif /* __CVMX_SPINLOCK_H__ */
|