nptl/sysdeps/unix/sysv/linux/powerpc/lowlevellock.h

   1 /* Copyright (C) 2003, 2004, 2006 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Paul Mackerras <paulus@au.ibm.com>, 2003.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    02111-1307 USA.  */
  19
  20 #ifndef _LOWLEVELLOCK_H
  21 #define _LOWLEVELLOCK_H 1
  22
  23 #include <time.h>
  24 #include <sys/param.h>
  25 #include <bits/pthreadtypes.h>
  26 #include <atomic.h>
  27
  28
  29 #ifndef __NR_futex
  30 # define __NR_futex             221
  31 #endif
  32 #define FUTEX_WAIT              0
  33 #define FUTEX_WAKE              1
  34 #define FUTEX_REQUEUE           3
  35 #define FUTEX_CMP_REQUEUE       4
  36 #define FUTEX_WAKE_OP           5
  37 #define FUTEX_OP_CLEAR_WAKE_IF_GT_ONE   ((4 << 24) | 1)
  38
  39 /* Initializer for compatibility lock.  */
  40 #define LLL_MUTEX_LOCK_INITIALIZER (0)
  41
  42 #define lll_futex_wait(futexp, val) \
  43   ({                                                                          \
  44     INTERNAL_SYSCALL_DECL (__err);                                            \
  45     long int __ret;                                                           \
  46                                                                               \
  47     __ret = INTERNAL_SYSCALL (futex, __err, 4,                                \
  48                               (futexp), FUTEX_WAIT, (val), 0);                \
  49     INTERNAL_SYSCALL_ERROR_P (__ret, __err) ? -__ret : __ret;                 \
  50   })
  51
  52 #define lll_futex_timed_wait(futexp, val, timespec) \
  53   ({                                                                          \
  54     INTERNAL_SYSCALL_DECL (__err);                                            \
  55     long int __ret;                                                           \
  56                                                                               \
  57     __ret = INTERNAL_SYSCALL (futex, __err, 4,                                \
  58                               (futexp), FUTEX_WAIT, (val), (timespec));       \
  59     INTERNAL_SYSCALL_ERROR_P (__ret, __err) ? -__ret : __ret;                 \
  60   })
  61
  62 #define lll_futex_wake(futexp, nr) \
  63   ({                                                                          \
  64     INTERNAL_SYSCALL_DECL (__err);                                            \
  65     long int __ret;                                                           \
  66                                                                               \
  67     __ret = INTERNAL_SYSCALL (futex, __err, 4,                                \
  68                               (futexp), FUTEX_WAKE, (nr), 0);                 \
  69     INTERNAL_SYSCALL_ERROR_P (__ret, __err) ? -__ret : __ret;                 \
  70   })
  71
  72 #define lll_robust_mutex_dead(futexv) \
  73   do                                                                          \
  74     {                                                                         \
  75       INTERNAL_SYSCALL_DECL (__err);                                          \
  76       int *__futexp = &(futexv);                                              \
  77                                                                               \
  78       atomic_or (__futexp, FUTEX_OWNER_DIED);                                 \
  79       INTERNAL_SYSCALL (futex, __err, 4, __futexp, FUTEX_WAKE, 1, 0);         \
  80     }                                                                         \
  81   while (0)
  82
  83 /* Returns non-zero if error happened, zero if success.  */
  84 #define lll_futex_requeue(futexp, nr_wake, nr_move, mutex, val) \
  85   ({                                                                          \
  86     INTERNAL_SYSCALL_DECL (__err);                                            \
  87     long int __ret;                                                           \
  88                                                                               \
  89     __ret = INTERNAL_SYSCALL (futex, __err, 6,                                \
  90                               (futexp), FUTEX_CMP_REQUEUE, (nr_wake),         \
  91                               (nr_move), (mutex), (val));                     \
  92     INTERNAL_SYSCALL_ERROR_P (__ret, __err);                                  \
  93   })
  94
  95 /* Returns non-zero if error happened, zero if success.  */
  96 #define lll_futex_wake_unlock(futexp, nr_wake, nr_wake2, futexp2) \
  97   ({                                                                          \
  98     INTERNAL_SYSCALL_DECL (__err);                                            \
  99     long int __ret;                                                           \
 100                                                                               \
 101     __ret = INTERNAL_SYSCALL (futex, __err, 6,                                \
 102                               (futexp), FUTEX_WAKE_OP, (nr_wake),             \
 103                               (nr_wake2), (futexp2),                          \
 104                               FUTEX_OP_CLEAR_WAKE_IF_GT_ONE);                 \
 105     INTERNAL_SYSCALL_ERROR_P (__ret, __err);                                  \
 106   })
 107
 108 #ifdef UP
 109 # define __lll_acq_instr        ""
 110 # define __lll_rel_instr        ""
 111 #else
 112 # define __lll_acq_instr        "isync"
 113 # ifdef _ARCH_PWR4
 114 /*
 115  * Newer powerpc64 processors support the new "light weight" sync (lwsync)
 116  * So if the build is using -mcpu=[power4,power5,power5+,970] we can
 117  * safely use lwsync.
 118  */
 119 #  define __lll_rel_instr       "lwsync"
 120 # else
 121 /*
 122  * Older powerpc32 processors don't support the new "light weight"
 123  * sync (lwsync).  So the only safe option is to use normal sync
 124  * for all powerpc32 applications.
 125  */
 126 #  define __lll_rel_instr       "sync"
 127 # endif
 128 #endif
 129
 130 /* Set *futex to ID if it is 0, atomically.  Returns the old value */
 131 #define __lll_robust_trylock(futex, id) \
 132   ({ int __val;                                                               \
 133      __asm __volatile ("1:      lwarx   %0,0,%2\n"                            \
 134                        "        cmpwi   0,%0,0\n"                             \
 135                        "        bne     2f\n"                                 \
 136                        "        stwcx.  %3,0,%2\n"                            \
 137                        "        bne-    1b\n"                                 \
 138                        "2:      " __lll_acq_instr                             \
 139                        : "=&r" (__val), "=m" (*futex)                         \
 140                        : "r" (futex), "r" (id), "m" (*futex)                  \
 141                        : "cr0", "memory");                                    \
 142      __val;                                                                   \
 143   })
 144
 145 #define lll_robust_mutex_trylock(lock, id) __lll_robust_trylock (&(lock), id)
 146
 147 /* Set *futex to 1 if it is 0, atomically.  Returns the old value */
 148 #define __lll_trylock(futex) __lll_robust_trylock (futex, 1)
 149
 150 #define lll_mutex_trylock(lock) __lll_trylock (&(lock))
 151
 152 /* Set *futex to 2 if it is 0, atomically.  Returns the old value */
 153 #define __lll_cond_trylock(futex) __lll_robust_trylock (futex, 2)
 154
 155 #define lll_mutex_cond_trylock(lock)    __lll_cond_trylock (&(lock))
 156
 157
 158 extern void __lll_lock_wait (int *futex) attribute_hidden;
 159 extern int __lll_robust_lock_wait (int *futex) attribute_hidden;
 160
 161 #define lll_mutex_lock(lock) \
 162   (void) ({                                                                   \
 163     int *__futex = &(lock);                                                   \
 164     if (__builtin_expect (atomic_compare_and_exchange_val_acq (__futex, 1, 0),\
 165                           0) != 0)                                            \
 166       __lll_lock_wait (__futex);                                              \
 167   })
 168
 169 #define lll_robust_mutex_lock(lock, id) \
 170   ({                                                                          \
 171     int *__futex = &(lock);                                                   \
 172     int __val = 0;                                                            \
 173     if (__builtin_expect (atomic_compare_and_exchange_bool_acq (__futex, id,  \
 174                                                                 0), 0))       \
 175       __val = __lll_robust_lock_wait (__futex);                               \
 176     __val;                                                                    \
 177   })
 178
 179 #define lll_mutex_cond_lock(lock) \
 180   (void) ({                                                                   \
 181     int *__futex = &(lock);                                                   \
 182     if (__builtin_expect (atomic_compare_and_exchange_val_acq (__futex, 2, 0),\
 183                           0) != 0)                                            \
 184       __lll_lock_wait (__futex);                                              \
 185   })
 186
 187 #define lll_robust_mutex_cond_lock(lock, id) \
 188   ({                                                                          \
 189     int *__futex = &(lock);                                                   \
 190     int __val = 0;                                                            \
 191     int __id = id | FUTEX_WAITERS;                                            \
 192     if (__builtin_expect (atomic_compare_and_exchange_bool_acq (__futex, __id,\
 193                                                                 0), 0))       \
 194       __val = __lll_robust_lock_wait (__futex);                               \
 195     __val;                                                                    \
 196   })
 197
 198
 199 extern int __lll_timedlock_wait
 200   (int *futex, const struct timespec *) attribute_hidden;
 201 extern int __lll_robust_timedlock_wait
 202   (int *futex, const struct timespec *) attribute_hidden;
 203
 204 #define lll_mutex_timedlock(lock, abstime) \
 205   ({                                                                          \
 206     int *__futex = &(lock);                                                   \
 207     int __val = 0;                                                            \
 208     if (__builtin_expect (atomic_compare_and_exchange_val_acq (__futex, 1, 0),\
 209                           0) != 0)                                            \
 210       __val = __lll_timedlock_wait (__futex, abstime);                        \
 211     __val;                                                                    \
 212   })
 213
 214 #define lll_robust_mutex_timedlock(lock, abstime, id) \
 215   ({                                                                          \
 216     int *__futex = &(lock);                                                   \
 217     int __val = 0;                                                            \
 218     if (__builtin_expect (atomic_compare_and_exchange_bool_acq (__futex, id,  \
 219                                                                 0), 0))       \
 220       __val = __lll_robust_timedlock_wait (__futex, abstime);                 \
 221     __val;                                                                    \
 222   })
 223
 224 #define lll_mutex_unlock(lock) \
 225   ((void) ({                                                                  \
 226     int *__futex = &(lock);                                                   \
 227     int __val = atomic_exchange_rel (__futex, 0);                             \
 228     if (__builtin_expect (__val > 1, 0))                                      \
 229       lll_futex_wake (__futex, 1);                                            \
 230   }))
 231
 232 #define lll_robust_mutex_unlock(lock) \
 233   ((void) ({                                                                  \
 234     int *__futex = &(lock);                                                   \
 235     int __val = atomic_exchange_rel (__futex, 0);                             \
 236     if (__builtin_expect (__val & FUTEX_WAITERS, 0))                          \
 237       lll_futex_wake (__futex, 1);                                            \
 238   }))
 239
 240 #define lll_mutex_unlock_force(lock) \
 241   ((void) ({                                                                  \
 242     int *__futex = &(lock);                                                   \
 243     *__futex = 0;                                                             \
 244     __asm __volatile (__lll_rel_instr ::: "memory");                          \
 245     lll_futex_wake (__futex, 1);                                              \
 246   }))
 247
 248 #define lll_mutex_islocked(futex) \
 249   (futex != 0)
 250
 251
 252 /* Our internal lock implementation is identical to the binary-compatible
 253    mutex implementation. */
 254
 255 /* Type for lock object.  */
 256 typedef int lll_lock_t;
 257
 258 /* Initializers for lock.  */
 259 #define LLL_LOCK_INITIALIZER            (0)
 260 #define LLL_LOCK_INITIALIZER_LOCKED     (1)
 261
 262 extern int lll_unlock_wake_cb (int *__futex) attribute_hidden;
 263
 264 /* The states of a lock are:
 265     0  -  untaken
 266     1  -  taken by one user
 267    >1  -  taken by more users */
 268
 269 #define lll_trylock(lock)       lll_mutex_trylock (lock)
 270 #define lll_lock(lock)          lll_mutex_lock (lock)
 271 #define lll_unlock(lock)        lll_mutex_unlock (lock)
 272 #define lll_islocked(lock)      lll_mutex_islocked (lock)
 273
 274 /* The kernel notifies a process which uses CLONE_CLEARTID via futex
 275    wakeup when the clone terminates.  The memory location contains the
 276    thread ID while the clone is running and is reset to zero
 277    afterwards.  */
 278 #define lll_wait_tid(tid) \
 279   do {                                                                        \
 280     __typeof (tid) __tid;                                                     \
 281     while ((__tid = (tid)) != 0)                                              \
 282       lll_futex_wait (&(tid), __tid);                                         \
 283   } while (0)
 284
 285 extern int __lll_timedwait_tid (int *, const struct timespec *)
 286      attribute_hidden;
 287
 288 #define lll_timedwait_tid(tid, abstime) \
 289   ({                                                                          \
 290     int __res = 0;                                                            \
 291     if ((tid) != 0)                                                           \
 292       __res = __lll_timedwait_tid (&(tid), (abstime));                        \
 293     __res;                                                                    \
 294   })
 295
 296
 297 /* Conditional variable handling.  */
 298
 299 extern void __lll_cond_wait (pthread_cond_t *cond)
 300      attribute_hidden;
 301 extern int __lll_cond_timedwait (pthread_cond_t *cond,
 302                                  const struct timespec *abstime)
 303      attribute_hidden;
 304 extern void __lll_cond_wake (pthread_cond_t *cond)
 305      attribute_hidden;
 306 extern void __lll_cond_broadcast (pthread_cond_t *cond)
 307      attribute_hidden;
 308
 309 #define lll_cond_wait(cond) \
 310   __lll_cond_wait (cond)
 311 #define lll_cond_timedwait(cond, abstime) \
 312   __lll_cond_timedwait (cond, abstime)
 313 #define lll_cond_wake(cond) \
 314   __lll_cond_wake (cond)
 315 #define lll_cond_broadcast(cond) \
 316   __lll_cond_broadcast (cond)
 317
 318 #endif  /* lowlevellock.h */