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
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
|
/* SPDX-License-Identifier: BSD-3-Clause
* Copyright(c) 2010-2014 Intel Corporation
*/
#ifndef _RTE_SPINLOCK_H_
#define _RTE_SPINLOCK_H_
/**
* @file
*
* RTE Spinlocks
*
* This file defines an API for read-write locks, which are implemented
* in an architecture-specific way. This kind of lock simply waits in
* a loop repeatedly checking until the lock becomes available.
*
* All locks must be initialised before use, and only initialised once.
*
*/
#include <rte_lcore.h>
#ifdef RTE_FORCE_INTRINSICS
#include <rte_common.h>
#endif
#include <rte_pause.h>
/**
* The rte_spinlock_t type.
*/
typedef struct {
volatile int locked; /**< lock status 0 = unlocked, 1 = locked */
} rte_spinlock_t;
/**
* A static spinlock initializer.
*/
#define RTE_SPINLOCK_INITIALIZER { 0 }
/**
* Initialize the spinlock to an unlocked state.
*
* @param sl
* A pointer to the spinlock.
*/
static inline void
rte_spinlock_init(rte_spinlock_t *sl)
{
sl->locked = 0;
}
/**
* Take the spinlock.
*
* @param sl
* A pointer to the spinlock.
*/
static inline void
rte_spinlock_lock(rte_spinlock_t *sl);
#ifdef RTE_FORCE_INTRINSICS
static inline void
rte_spinlock_lock(rte_spinlock_t *sl)
{
int exp = 0;
while (!__atomic_compare_exchange_n(&sl->locked, &exp, 1, 0,
__ATOMIC_ACQUIRE, __ATOMIC_RELAXED)) {
while (__atomic_load_n(&sl->locked, __ATOMIC_RELAXED))
rte_pause();
exp = 0;
}
}
#endif
/**
* Release the spinlock.
*
* @param sl
* A pointer to the spinlock.
*/
static inline void
rte_spinlock_unlock (rte_spinlock_t *sl);
#ifdef RTE_FORCE_INTRINSICS
static inline void
rte_spinlock_unlock (rte_spinlock_t *sl)
{
__atomic_store_n(&sl->locked, 0, __ATOMIC_RELEASE);
}
#endif
/**
* Try to take the lock.
*
* @param sl
* A pointer to the spinlock.
* @return
* 1 if the lock is successfully taken; 0 otherwise.
*/
static inline int
rte_spinlock_trylock (rte_spinlock_t *sl);
#ifdef RTE_FORCE_INTRINSICS
static inline int
rte_spinlock_trylock (rte_spinlock_t *sl)
{
int exp = 0;
return __atomic_compare_exchange_n(&sl->locked, &exp, 1,
0, /* disallow spurious failure */
__ATOMIC_ACQUIRE, __ATOMIC_RELAXED);
}
#endif
/**
* Test if the lock is taken.
*
* @param sl
* A pointer to the spinlock.
* @return
* 1 if the lock is currently taken; 0 otherwise.
*/
static inline int rte_spinlock_is_locked (rte_spinlock_t *sl)
{
return __atomic_load_n(&sl->locked, __ATOMIC_ACQUIRE);
}
/**
* Test if hardware transactional memory (lock elision) is supported
*
* @return
* 1 if the hardware transactional memory is supported; 0 otherwise.
*/
static inline int rte_tm_supported(void);
/**
* Try to execute critical section in a hardware memory transaction,
* if it fails or not available take the spinlock.
*
* NOTE: An attempt to perform a HW I/O operation inside a hardware memory
* transaction always aborts the transaction since the CPU is not able to
* roll-back should the transaction fail. Therefore, hardware transactional
* locks are not advised to be used around rte_eth_rx_burst() and
* rte_eth_tx_burst() calls.
*
* @param sl
* A pointer to the spinlock.
*/
static inline void
rte_spinlock_lock_tm(rte_spinlock_t *sl);
/**
* Commit hardware memory transaction or release the spinlock if
* the spinlock is used as a fall-back
*
* @param sl
* A pointer to the spinlock.
*/
static inline void
rte_spinlock_unlock_tm(rte_spinlock_t *sl);
/**
* Try to execute critical section in a hardware memory transaction,
* if it fails or not available try to take the lock.
*
* NOTE: An attempt to perform a HW I/O operation inside a hardware memory
* transaction always aborts the transaction since the CPU is not able to
* roll-back should the transaction fail. Therefore, hardware transactional
* locks are not advised to be used around rte_eth_rx_burst() and
* rte_eth_tx_burst() calls.
*
* @param sl
* A pointer to the spinlock.
* @return
* 1 if the hardware memory transaction is successfully started
* or lock is successfully taken; 0 otherwise.
*/
static inline int
rte_spinlock_trylock_tm(rte_spinlock_t *sl);
/**
* The rte_spinlock_recursive_t type.
*/
typedef struct {
rte_spinlock_t sl; /**< the actual spinlock */
volatile int user; /**< core id using lock, -1 for unused */
volatile int count; /**< count of time this lock has been called */
} rte_spinlock_recursive_t;
/**
* A static recursive spinlock initializer.
*/
#define RTE_SPINLOCK_RECURSIVE_INITIALIZER {RTE_SPINLOCK_INITIALIZER, -1, 0}
/**
* Initialize the recursive spinlock to an unlocked state.
*
* @param slr
* A pointer to the recursive spinlock.
*/
static inline void rte_spinlock_recursive_init(rte_spinlock_recursive_t *slr)
{
rte_spinlock_init(&slr->sl);
slr->user = -1;
slr->count = 0;
}
/**
* Take the recursive spinlock.
*
* @param slr
* A pointer to the recursive spinlock.
*/
static inline void rte_spinlock_recursive_lock(rte_spinlock_recursive_t *slr)
{
int id = rte_gettid();
if (slr->user != id) {
rte_spinlock_lock(&slr->sl);
slr->user = id;
}
slr->count++;
}
/**
* Release the recursive spinlock.
*
* @param slr
* A pointer to the recursive spinlock.
*/
static inline void rte_spinlock_recursive_unlock(rte_spinlock_recursive_t *slr)
{
if (--(slr->count) == 0) {
slr->user = -1;
rte_spinlock_unlock(&slr->sl);
}
}
/**
* Try to take the recursive lock.
*
* @param slr
* A pointer to the recursive spinlock.
* @return
* 1 if the lock is successfully taken; 0 otherwise.
*/
static inline int rte_spinlock_recursive_trylock(rte_spinlock_recursive_t *slr)
{
int id = rte_gettid();
if (slr->user != id) {
if (rte_spinlock_trylock(&slr->sl) == 0)
return 0;
slr->user = id;
}
slr->count++;
return 1;
}
/**
* Try to execute critical section in a hardware memory transaction,
* if it fails or not available take the recursive spinlocks
*
* NOTE: An attempt to perform a HW I/O operation inside a hardware memory
* transaction always aborts the transaction since the CPU is not able to
* roll-back should the transaction fail. Therefore, hardware transactional
* locks are not advised to be used around rte_eth_rx_burst() and
* rte_eth_tx_burst() calls.
*
* @param slr
* A pointer to the recursive spinlock.
*/
static inline void rte_spinlock_recursive_lock_tm(
rte_spinlock_recursive_t *slr);
/**
* Commit hardware memory transaction or release the recursive spinlock
* if the recursive spinlock is used as a fall-back
*
* @param slr
* A pointer to the recursive spinlock.
*/
static inline void rte_spinlock_recursive_unlock_tm(
rte_spinlock_recursive_t *slr);
/**
* Try to execute critical section in a hardware memory transaction,
* if it fails or not available try to take the recursive lock
*
* NOTE: An attempt to perform a HW I/O operation inside a hardware memory
* transaction always aborts the transaction since the CPU is not able to
* roll-back should the transaction fail. Therefore, hardware transactional
* locks are not advised to be used around rte_eth_rx_burst() and
* rte_eth_tx_burst() calls.
*
* @param slr
* A pointer to the recursive spinlock.
* @return
* 1 if the hardware memory transaction is successfully started
* or lock is successfully taken; 0 otherwise.
*/
static inline int rte_spinlock_recursive_trylock_tm(
rte_spinlock_recursive_t *slr);
#endif /* _RTE_SPINLOCK_H_ */
|
