osfmk/i386/lock.h

   1 /*
   2  * Copyright (c) 2000-2004 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_OSREFERENCE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License.  The rights granted to you under the
  10  * License may not be used to create, or enable the creation or
  11  * redistribution of, unlawful or unlicensed copies of an Apple operating
  12  * system, or to circumvent, violate, or enable the circumvention or
  13  * violation of, any terms of an Apple operating system software license
  14  * agreement.
  15  *
  16  * Please obtain a copy of the License at
  17  * http://www.opensource.apple.com/apsl/ and read it before using this
  18  * file.
  19  *
  20  * The Original Code and all software distributed under the License are
  21  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  22  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  23  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  24  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  25  * Please see the License for the specific language governing rights and
  26  * limitations under the License.
  27  *
  28  * @APPLE_LICENSE_OSREFERENCE_HEADER_END@
  29  */
  30 /*
  31  * Copyright (C) 1998 Apple Computer
  32  * All Rights Reserved
  33  */
  34 /*
  35  * @OSF_COPYRIGHT@
  36  */
  37 /*
  38  * Mach Operating System
  39  * Copyright (c) 1991,1990 Carnegie Mellon University
  40  * All Rights Reserved.
  41  *
  42  * Permission to use, copy, modify and distribute this software and its
  43  * documentation is hereby granted, provided that both the copyright
  44  * notice and this permission notice appear in all copies of the
  45  * software, derivative works or modified versions, and any portions
  46  * thereof, and that both notices appear in supporting documentation.
  47  *
  48  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
  49  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
  50  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
  51  *
  52  * Carnegie Mellon requests users of this software to return to
  53  *
  54  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
  55  *  School of Computer Science
  56  *  Carnegie Mellon University
  57  *  Pittsburgh PA 15213-3890
  58  *
  59  * any improvements or extensions that they make and grant Carnegie Mellon
  60  * the rights to redistribute these changes.
  61  */
  62
  63 /*
  64  */
  65
  66 /*
  67  * Machine-dependent simple locks for the i386.
  68  */
  69 #ifdef  KERNEL_PRIVATE
  70
  71 #ifndef _I386_LOCK_H_
  72 #define _I386_LOCK_H_
  73
  74 #include <sys/appleapiopts.h>
  75
  76 #ifdef __APPLE_API_PRIVATE
  77
  78 #ifdef MACH_KERNEL_PRIVATE
  79
  80 #include <kern/macro_help.h>
  81 #include <kern/assert.h>
  82 #include <i386/hw_lock_types.h>
  83 #include <i386/locks.h>
  84
  85 #include <mach_rt.h>
  86 #include <mach_ldebug.h>
  87
  88 typedef struct {
  89         lck_mtx_t       lck_mtx;        /* inlined lck_mtx, need to be first */
  90 #if     MACH_LDEBUG
  91         int                             type;
  92 #define MUTEX_TAG       0x4d4d
  93         vm_offset_t             pc;
  94         vm_offset_t             thread;
  95 #endif  /* MACH_LDEBUG */
  96 } mutex_t;
  97
  98 typedef lck_rw_t lock_t;
  99
 100 extern unsigned int LockTimeOut;                        /* Number of hardware ticks of a lock timeout */
 101
 102
 103 #if defined(__GNUC__)
 104
 105 /*
 106  *      General bit-lock routines.
 107  */
 108
 109 #define bit_lock(bit,l)                                                 \
 110         __asm__ volatile("      jmp     1f      \n                      \
 111                         0:      btl     %0, %1  \n                      \
 112                                 jb      0b      \n                      \
 113                         1:      lock            \n                      \
 114                                 btsl    %0,%1   \n                      \
 115                                 jb      0b"                     :       \
 116                                                                 :       \
 117                         "r" (bit), "m" (*(volatile int *)(l))   :       \
 118                         "memory");
 119
 120 #define bit_unlock(bit,l)                                               \
 121         __asm__ volatile("      lock            \n                      \
 122                                 btrl    %0,%1"                  :       \
 123                                                                 :       \
 124                         "r" (bit), "m" (*(volatile int *)(l)));
 125
 126 /*
 127  *      Set or clear individual bits in a long word.
 128  *      The locked access is needed only to lock access
 129  *      to the word, not to individual bits.
 130  */
 131
 132 #define i_bit_set(bit,l)                                                \
 133         __asm__ volatile("      lock            \n                      \
 134                                 btsl    %0,%1"                  :       \
 135                                                                 :       \
 136                         "r" (bit), "m" (*(volatile int *)(l)));
 137
 138 #define i_bit_clear(bit,l)                                              \
 139         __asm__ volatile("      lock            \n                      \
 140                                 btrl    %0,%1"                  :       \
 141                                                                 :       \
 142                         "r" (bit), "m" (*(volatile int *)(l)));
 143
 144 static inline unsigned long i_bit_isset(unsigned int test, volatile unsigned long *word)
 145 {
 146         int     bit;
 147
 148         __asm__ volatile("btl %2,%1\n\tsbbl %0,%0" : "=r" (bit)
 149                 : "m" (word), "ir" (test));
 150         return bit;
 151 }
 152
 153 static inline char      xchgb(volatile char * cp, char new);
 154
 155 static inline void      atomic_incl(volatile long * p, long delta);
 156 static inline void      atomic_incs(volatile short * p, short delta);
 157 static inline void      atomic_incb(volatile char * p, char delta);
 158
 159 static inline void      atomic_decl(volatile long * p, long delta);
 160 static inline void      atomic_decs(volatile short * p, short delta);
 161 static inline void      atomic_decb(volatile char * p, char delta);
 162
 163 static inline long      atomic_getl(const volatile long * p);
 164 static inline short     atomic_gets(const volatile short * p);
 165 static inline char      atomic_getb(const volatile char * p);
 166
 167 static inline void      atomic_setl(volatile long * p, long value);
 168 static inline void      atomic_sets(volatile short * p, short value);
 169 static inline void      atomic_setb(volatile char * p, char value);
 170
 171 static inline char      xchgb(volatile char * cp, char new)
 172 {
 173         register char   old = new;
 174
 175         __asm__ volatile ("     xchgb   %0,%2"                  :
 176                         "=q" (old)                              :
 177                         "0" (new), "m" (*(volatile char *)cp) : "memory");
 178         return (old);
 179 }
 180
 181 /*
 182  * Compare and exchange:
 183  * - returns failure (0) if the location did not contain the old value,
 184  * - returns success (1) if the location was set to the new value.
 185  */
 186 static inline uint32_t
 187 atomic_cmpxchg(uint32_t *p, uint32_t old, uint32_t new)
 188 {
 189         uint32_t res = old;
 190
 191         asm volatile(
 192                 "lock;  cmpxchgl        %1,%2;  \n\t"
 193                 "       setz            %%al;   \n\t"
 194                 "       movzbl          %%al,%0"
 195                 : "+a" (res)    /* %0: old value to compare, returns success */
 196                 : "r" (new),    /* %1: new value to set */
 197                   "m" (*(p))    /* %2: memory address */
 198                 : "memory");
 199         return (res);
 200 }
 201
 202 static inline void      atomic_incl(volatile long * p, long delta)
 203 {
 204         __asm__ volatile ("     lock            \n              \
 205                                 addl    %0,%1"          :       \
 206                                                         :       \
 207                                 "r" (delta), "m" (*(volatile long *)p));
 208 }
 209
 210 static inline void      atomic_incs(volatile short * p, short delta)
 211 {
 212         __asm__ volatile ("     lock            \n              \
 213                                 addw    %0,%1"          :       \
 214                                                         :       \
 215                                 "q" (delta), "m" (*(volatile short *)p));
 216 }
 217
 218 static inline void      atomic_incb(volatile char * p, char delta)
 219 {
 220         __asm__ volatile ("     lock            \n              \
 221                                 addb    %0,%1"          :       \
 222                                                         :       \
 223                                 "q" (delta), "m" (*(volatile char *)p));
 224 }
 225
 226 static inline void      atomic_decl(volatile long * p, long delta)
 227 {
 228         __asm__ volatile ("     lock            \n              \
 229                                 subl    %0,%1"          :       \
 230                                                         :       \
 231                                 "r" (delta), "m" (*(volatile long *)p));
 232 }
 233
 234 static inline int       atomic_decl_and_test(volatile long * p, long delta)
 235 {
 236         uint8_t ret;
 237         asm volatile (
 238                 "       lock            \n\t"
 239                 "       subl    %1,%2   \n\t"
 240                 "       sete    %0"
 241                 : "=qm" (ret)
 242                 : "r" (delta), "m" (*(volatile long *)p));
 243         return ret;
 244 }
 245
 246 static inline void      atomic_decs(volatile short * p, short delta)
 247 {
 248         __asm__ volatile ("     lock            \n              \
 249                                 subw    %0,%1"          :       \
 250                                                         :       \
 251                                 "q" (delta), "m" (*(volatile short *)p));
 252 }
 253
 254 static inline void      atomic_decb(volatile char * p, char delta)
 255 {
 256         __asm__ volatile ("     lock            \n              \
 257                                 subb    %0,%1"          :       \
 258                                                         :       \
 259                                 "q" (delta), "m" (*(volatile char *)p));
 260 }
 261
 262 static inline long      atomic_getl(const volatile long * p)
 263 {
 264         return (*p);
 265 }
 266
 267 static inline short     atomic_gets(const volatile short * p)
 268 {
 269         return (*p);
 270 }
 271
 272 static inline char      atomic_getb(const volatile char * p)
 273 {
 274         return (*p);
 275 }
 276
 277 static inline void      atomic_setl(volatile long * p, long value)
 278 {
 279         *p = value;
 280 }
 281
 282 static inline void      atomic_sets(volatile short * p, short value)
 283 {
 284         *p = value;
 285 }
 286
 287 static inline void      atomic_setb(volatile char * p, char value)
 288 {
 289         *p = value;
 290 }
 291
 292
 293 #else   /* !defined(__GNUC__) */
 294
 295 extern void     i_bit_set(
 296         int index,
 297         void *addr);
 298
 299 extern void     i_bit_clear(
 300         int index,
 301         void *addr);
 302
 303 extern void bit_lock(
 304         int index,
 305         void *addr);
 306
 307 extern void bit_unlock(
 308         int index,
 309         void *addr);
 310
 311 /*
 312  * All other routines defined in __GNUC__ case lack
 313  * definitions otherwise. - XXX
 314  */
 315
 316 #endif  /* !defined(__GNUC__) */
 317
 318 extern void             kernel_preempt_check (void);
 319
 320 #endif /* MACH_KERNEL_PRIVATE */
 321
 322 #endif /* __APLE_API_PRIVATE */
 323
 324 #endif  /* _I386_LOCK_H_ */
 325
 326 #endif  /* KERNEL_PRIVATE */