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
306
307
308
309
310
311
312
313
314
315
316
317
318
|
/*-
* Copyright (c) 1997 Berkeley Software Design, Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. 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.
* 3. Berkeley Software Design Inc's name may not be used to endorse or
* promote products derived from this software without specific prior
* written permission.
*
* THIS SOFTWARE IS PROVIDED BY BERKELEY SOFTWARE DESIGN INC ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL BERKELEY SOFTWARE DESIGN INC BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* from BSDI $Id: mutex.h,v 2.7.2.35 2000/04/27 03:10:26 cp Exp $
* $FreeBSD$
*/
#ifndef _MACHINE_MUTEX_H_
#define _MACHINE_MUTEX_H_
#ifndef LOCORE
#ifdef _KERNEL
#include <machine/psl.h>
/* Global locks */
extern struct mtx clock_lock;
#define mtx_legal2block() (read_eflags() & PSL_I)
#define mtx_intr_enable(mutex) (mutex)->mtx_saveintr |= PSL_I
/*
* Assembly macros (for internal use only)
*------------------------------------------------------------------------------
*/
#define _V(x) __STRING(x)
#if 0
/* #ifndef I386_CPU */
/*
* For 486 and newer processors.
*/
/* Get a sleep lock, deal with recursion inline. */
#define _getlock_sleep(mtxp, tid, type) ({ \
int _res = MTX_UNOWNED; \
\
__asm __volatile ( \
" " MPLOCKED "" \
" cmpxchgl %3,%1;" /* Try */ \
" jz 1f;" /* Got it */ \
" andl $" _V(MTX_FLAGMASK) ",%0;" /* turn off spec bits */ \
" cmpl %0,%3;" /* already have it? */ \
" je 2f;" /* yes, recurse */ \
" pushl %4;" \
" pushl %5;" \
" call mtx_enter_hard;" \
" addl $8,%%esp;" \
" jmp 1f;" \
"2:" \
" " MPLOCKED "" \
" orl $" _V(MTX_RECURSE) ",%1;" \
" incl %2;" \
"1:" \
"# getlock_sleep" \
: "+a" (_res), /* 0 */ \
"+m" (mtxp->mtx_lock), /* 1 */ \
"+m" (mtxp->mtx_recurse) /* 2 */ \
: "r" (tid), /* 3 (input) */ \
"gi" (type), /* 4 */ \
"g" (mtxp) /* 5 */ \
: "cc", "memory", "ecx", "edx" /* used */ ); \
})
/* Get a spin lock, handle recursion inline (as the less common case) */
#define _getlock_spin_block(mtxp, tid, type) ({ \
int _res = MTX_UNOWNED; \
\
__asm __volatile ( \
" pushfl;" \
" cli;" \
" " MPLOCKED "" \
" cmpxchgl %3,%1;" /* Try */ \
" jz 2f;" /* got it */ \
" pushl %4;" \
" pushl %5;" \
" call mtx_enter_hard;" /* mtx_enter_hard(mtxp, type, oflags) */ \
" addl $12,%%esp;" \
" jmp 1f;" \
"2: popl %2;" /* save flags */ \
"1:" \
"# getlock_spin_block" \
: "+a" (_res), /* 0 */ \
"+m" (mtxp->mtx_lock), /* 1 */ \
"=m" (mtxp->mtx_saveintr) /* 2 */ \
: "r" (tid), /* 3 (input) */ \
"gi" (type), /* 4 */ \
"g" (mtxp) /* 5 */ \
: "cc", "memory", "ecx", "edx" /* used */ ); \
})
/*
* Get a lock without any recursion handling. Calls the hard enter function if
* we can't get it inline.
*/
#define _getlock_norecurse(mtxp, tid, type) ({ \
int _res = MTX_UNOWNED; \
\
__asm __volatile ( \
" " MPLOCKED "" \
" cmpxchgl %2,%1;" /* Try */ \
" jz 1f;" /* got it */ \
" pushl %3;" \
" pushl %4;" \
" call mtx_enter_hard;" /* mtx_enter_hard(mtxp, type) */ \
" addl $8,%%esp;" \
"1:" \
"# getlock_norecurse" \
: "+a" (_res), /* 0 */ \
"+m" (mtxp->mtx_lock) /* 1 */ \
: "r" (tid), /* 2 (input) */ \
"gi" (type), /* 3 */ \
"g" (mtxp) /* 4 */ \
: "cc", "memory", "ecx", "edx" /* used */ ); \
})
/*
* Release a sleep lock assuming we haven't recursed on it, recursion is handled
* in the hard function.
*/
#define _exitlock_norecurse(mtxp, tid, type) ({ \
int _tid = (int)(tid); \
\
__asm __volatile ( \
" " MPLOCKED "" \
" cmpxchgl %4,%0;" /* try easy rel */ \
" jz 1f;" /* released! */ \
" pushl %2;" \
" pushl %3;" \
" call mtx_exit_hard;" \
" addl $8,%%esp;" \
"1:" \
"# exitlock_norecurse" \
: "+m" (mtxp->mtx_lock), /* 0 */ \
"+a" (_tid) /* 1 */ \
: "gi" (type), /* 2 (input) */ \
"g" (mtxp), /* 3 */ \
"r" (MTX_UNOWNED) /* 4 */ \
: "cc", "memory", "ecx", "edx" /* used */ ); \
})
/*
* Release a sleep lock when its likely we recursed (the code to
* deal with simple recursion is inline).
*/
#define _exitlock(mtxp, tid, type) ({ \
int _tid = (int)(tid); \
\
__asm __volatile ( \
" " MPLOCKED "" \
" cmpxchgl %5,%0;" /* try easy rel */ \
" jz 1f;" /* released! */ \
" testl $" _V(MTX_RECURSE) ",%%eax;" /* recursed? */ \
" jnz 3f;" /* handle recursion */ \
/* Lock not recursed and contested: do the hard way */ \
" pushl %3;" \
" pushl %4;" \
" call mtx_exit_hard;" /* mtx_exit_hard(mtxp,type) */ \
" addl $8,%%esp;" \
" jmp 1f;" \
/* lock recursed, lower recursion level */ \
"3: decl %1;" /* one less level */ \
" jnz 1f;" /* still recursed, done */ \
" lock; andl $~" _V(MTX_RECURSE) ",%0;" /* turn off recurse flag */ \
"1:" \
"# exitlock" \
: "+m" (mtxp->mtx_lock), /* 0 */ \
"+m" (mtxp->mtx_recurse), /* 1 */ \
"+a" (_tid) /* 2 */ \
: "gi" (type), /* 3 (input) */ \
"g" (mtxp), /* 4 */ \
"r" (MTX_UNOWNED) /* 5 */ \
: "cc", "memory", "ecx", "edx" /* used */ ); \
})
/*
* Release a spin lock (with possible recursion).
*
* We use xchgl to clear lock (instead of simple store) to flush posting
* buffers and make the change visible to other CPU's.
*/
#define _exitlock_spin(mtxp) ({ \
int _res; \
\
__asm __volatile ( \
" movl %1,%2;" \
" decl %2;" \
" js 1f;" \
" movl %2,%1;" \
" jmp 2f;" \
"1: movl $ " _V(MTX_UNOWNED) ",%2;" \
" pushl %3;" \
" xchgl %2,%0;" \
" popfl;" \
"2:" \
"# exitlock_spin" \
: "+m" (mtxp->mtx_lock), /* 0 */ \
"+m" (mtxp->mtx_recurse), /* 1 */ \
"=r" (_res) /* 2 */ \
: "g" (mtxp->mtx_saveintr) /* 3 */ \
: "cc", "memory", "ecx" /* used */ ); \
})
#endif /* I386_CPU */
#undef _V
#endif /* _KERNEL */
#else /* !LOCORE */
/*
* Simple assembly macros to get and release mutexes.
*
* Note: All of these macros accept a "flags" argument and are analoguous
* to the mtx_lock_flags and mtx_unlock_flags general macros. If one
* desires to not pass a flag, the value 0 may be passed as second
* argument.
*
* XXX: We only have MTX_LOCK_SPIN and MTX_UNLOCK_SPIN for now, since that's
* all we use right now. We should add MTX_LOCK and MTX_UNLOCK (for sleep
* locks) in the near future, however.
*/
#define MTX_LOCK_SPIN(lck, flags) \
pushl %eax ; \
pushl %ecx ; \
pushl %ebx ; \
movl $(MTX_UNOWNED) , %eax ; \
movl PCPU(CURPROC), %ebx ; \
pushfl ; \
popl %ecx ; \
cli ; \
MPLOCKED cmpxchgl %ebx, lck+MTX_LOCK ; \
jz 2f ; \
cmpl lck+MTX_LOCK, %ebx ; \
je 3f ; \
pushl $0 ; \
pushl $0 ; \
pushl %ecx ; \
pushl $flags ; \
pushl $lck ; \
call _mtx_lock_spin ; \
addl $0x14, %esp ; \
jmp 1f ; \
3: movl lck+MTX_RECURSECNT, %ebx ; \
incl %ebx ; \
movl %ebx, lck+MTX_RECURSECNT ; \
jmp 1f ; \
2: movl %ecx, lck+MTX_SAVEINTR ; \
1: popl %ebx ; \
popl %ecx ; \
popl %eax
#define MTX_UNLOCK_SPIN(lck) \
pushl %edx ; \
pushl %eax ; \
movl lck+MTX_SAVEINTR, %edx ; \
movl lck+MTX_RECURSECNT, %eax ; \
testl %eax, %eax ; \
jne 2f ; \
movl $(MTX_UNOWNED), %eax ; \
xchgl %eax, lck+MTX_LOCK ; \
pushl %edx ; \
popfl ; \
jmp 1f ; \
2: decl %eax ; \
movl %eax, lck+MTX_RECURSECNT ; \
1: popl %eax ; \
popl %edx
/*
* XXX: These two are broken right now and need to be made to work for
* XXX: sleep locks, as the above two work for spin locks. We're not in
* XXX: too much of a rush to do these as we do not use them right now.
*/
#define MTX_ENTER(lck, type) \
pushl $0 ; /* dummy __LINE__ */ \
pushl $0 ; /* dummy __FILE__ */ \
pushl $type ; \
pushl $lck ; \
call _mtx_lock_XXX ; \
addl $16,%esp
#define MTX_EXIT(lck, type) \
pushl $0 ; /* dummy __LINE__ */ \
pushl $0 ; /* dummy __FILE__ */ \
pushl $type ; \
pushl $lck ; \
call _mtx_unlock_XXX ; \
addl $16,%esp
#endif /* !LOCORE */
#endif /* __MACHINE_MUTEX_H */
|
