osfmk/i386/lock.h

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