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

   1 /* Copyright (C) 2003, 2004 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 Libr    \ary; 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 #define __NR_futex              221
  30 #define FUTEX_WAIT              0
  31 #define FUTEX_WAKE              1
  32 #define FUTEX_REQUEUE           3
  33
  34 /* Initializer for compatibility lock.  */
  35 #define LLL_MUTEX_LOCK_INITIALIZER (0)
  36
  37 #define lll_futex_wait(futexp, val) \
  38   ({                                                                          \
  39     INTERNAL_SYSCALL_DECL (__err);                                            \
  40     long int __ret;                                                           \
  41                                                                               \
  42     __ret = INTERNAL_SYSCALL (futex, __err, 4,                                \
  43                               (futexp), FUTEX_WAIT, (val), 0);                \
  44     INTERNAL_SYSCALL_ERROR_P (__ret, __err) ? -__ret : __ret;                 \
  45   })
  46
  47 #define lll_futex_timed_wait(futexp, val, timespec) \
  48   ({                                                                          \
  49     INTERNAL_SYSCALL_DECL (__err);                                            \
  50     long int __ret;                                                           \
  51                                                                               \
  52     __ret = INTERNAL_SYSCALL (futex, __err, 4,                                \
  53                               (futexp), FUTEX_WAIT, (val), (timespec));       \
  54     INTERNAL_SYSCALL_ERROR_P (__ret, __err) ? -__ret : __ret;                 \
  55   })
  56
  57 #define lll_futex_wake(futexp, nr) \
  58   ({                                                                          \
  59     INTERNAL_SYSCALL_DECL (__err);                                            \
  60     long int __ret;                                                           \
  61                                                                               \
  62     __ret = INTERNAL_SYSCALL (futex, __err, 4,                                \
  63                               (futexp), FUTEX_WAKE, (nr), 0);                 \
  64     INTERNAL_SYSCALL_ERROR_P (__ret, __err) ? -__ret : __ret;                 \
  65   })
  66
  67 #define lll_futex_requeue(futexp, nr_wake, nr_move, mutex) \
  68   ({                                                                          \
  69     INTERNAL_SYSCALL_DECL (__err);                                            \
  70     long int __ret;                                                           \
  71                                                                               \
  72     __ret = INTERNAL_SYSCALL (futex, __err, 5,                                \
  73                               (futexp), FUTEX_REQUEUE, (nr_wake), (nr_move),  \
  74                               (mutex));                                       \
  75     INTERNAL_SYSCALL_ERROR_P (__ret, __err) ? -__ret : __ret;                 \
  76   })
  77
  78 #ifdef UP
  79 # define __lll_acq_instr        ""
  80 # define __lll_rel_instr        ""
  81 #else
  82 # define __lll_acq_instr        "isync"
  83 # define __lll_rel_instr        "sync"
  84 #endif
  85
  86 /* Set *futex to 1 if it is 0, atomically.  Returns the old value */
  87 #define __lll_trylock(futex) \
  88   ({ int __val;                                                               \
  89      __asm __volatile ("1:      lwarx   %0,0,%2\n"                            \
  90                        "        cmpwi   0,%0,0\n"                             \
  91                        "        bne     2f\n"                                 \
  92                        "        stwcx.  %3,0,%2\n"                            \
  93                        "        bne-    1b\n"                                 \
  94                        "2:      " __lll_acq_instr                             \
  95                        : "=&r" (__val), "=m" (*futex)                         \
  96                        : "r" (futex), "r" (1), "1" (*futex)                   \
  97                        : "cr0", "memory");                                    \
  98      __val;                                                                   \
  99   })
 100
 101 #define lll_mutex_trylock(lock) __lll_trylock (&(lock))
 102
 103 /* Set *futex to 2 if it is 0, atomically.  Returns the old value */
 104 #define __lll_cond_trylock(futex) \
 105   ({ int __val;                                                               \
 106      __asm __volatile ("1:      lwarx   %0,0,%2\n"                            \
 107                        "        cmpwi   0,%0,0\n"                             \
 108                        "        bne     2f\n"                                 \
 109                        "        stwcx.  %3,0,%2\n"                            \
 110                        "        bne-    1b\n"                                 \
 111                        "2:      " __lll_acq_instr                             \
 112                        : "=&r" (__val), "=m" (*futex)                         \
 113                        : "r" (futex), "r" (2), "1" (*futex)                   \
 114                        : "cr0", "memory");                                    \
 115      __val;                                                                   \
 116   })
 117 #define lll_mutex_cond_trylock(lock)    __lll_cond_trylock (&(lock))
 118
 119
 120 extern void __lll_lock_wait (int *futex) attribute_hidden;
 121
 122 #define lll_mutex_lock(lock) \
 123   (void) ({                                                                   \
 124     int *__futex = &(lock);                                                   \
 125     if (__builtin_expect (atomic_compare_and_exchange_val_acq (__futex, 1, 0),\
 126                           0) != 0)                                            \
 127       __lll_lock_wait (__futex);                                              \
 128   })
 129
 130 #define lll_mutex_cond_lock(lock) \
 131   (void) ({                                                                   \
 132     int *__futex = &(lock);                                                   \
 133     if (__builtin_expect (atomic_compare_and_exchange_val_acq (__futex, 2, 0),\
 134                           0) != 0)                                            \
 135       __lll_lock_wait (__futex);                                              \
 136   })
 137
 138 extern int __lll_timedlock_wait
 139   (int *futex, const struct timespec *) attribute_hidden;
 140
 141 #define lll_mutex_timedlock(lock, abstime) \
 142   ({                                                                          \
 143     int *__futex = &(lock);                                                   \
 144     int __val = 0;                                                            \
 145     if (__builtin_expect (atomic_compare_and_exchange_val_acq (__futex, 1, 0),\
 146                           0) != 0)                                            \
 147       __val = __lll_timedlock_wait (__futex, abstime);                        \
 148     __val;                                                                    \
 149   })
 150
 151 #define lll_mutex_unlock(lock) \
 152   ((void) ({                                                                  \
 153     int *__futex = &(lock);                                                   \
 154     int __val = atomic_exchange_rel (__futex, 0);                             \
 155     if (__builtin_expect (__val > 1, 0))                                      \
 156       lll_futex_wake (__futex, 1);                                            \
 157   }))
 158
 159 #define lll_mutex_unlock_force(lock) \
 160   ((void) ({                                                                  \
 161     int *__futex = &(lock);                                                   \
 162     *__futex = 0;                                                             \
 163     __asm __volatile (__lll_rel_instr ::: "memory");                          \
 164     lll_futex_wake (__futex, 1);                                              \
 165   }))
 166
 167 #define lll_mutex_islocked(futex) \
 168   (futex != 0)
 169
 170
 171 /* Our internal lock implementation is identical to the binary-compatible
 172    mutex implementation. */
 173
 174 /* Type for lock object.  */
 175 typedef int lll_lock_t;
 176
 177 /* Initializers for lock.  */
 178 #define LLL_LOCK_INITIALIZER            (0)
 179 #define LLL_LOCK_INITIALIZER_LOCKED     (1)
 180
 181 extern int lll_unlock_wake_cb (int *__futex) attribute_hidden;
 182
 183 /* The states of a lock are:
 184     0  -  untaken
 185     1  -  taken by one user
 186    >1  -  taken by more users */
 187
 188 #define lll_trylock(lock)       lll_mutex_trylock (lock)
 189 #define lll_lock(lock)          lll_mutex_lock (lock)
 190 #define lll_unlock(lock)        lll_mutex_unlock (lock)
 191 #define lll_islocked(lock)      lll_mutex_islocked (lock)
 192
 193 /* The kernel notifies a process which uses CLONE_CLEARTID via futex
 194    wakeup when the clone terminates.  The memory location contains the
 195    thread ID while the clone is running and is reset to zero
 196    afterwards.  */
 197 #define lll_wait_tid(tid) \
 198   do {                                                                        \
 199     __typeof (tid) __tid;                                                     \
 200     while ((__tid = (tid)) != 0)                                              \
 201       lll_futex_wait (&(tid), __tid);                                         \
 202   } while (0)
 203
 204 extern int __lll_timedwait_tid (int *, const struct timespec *)
 205      attribute_hidden;
 206
 207 #define lll_timedwait_tid(tid, abstime) \
 208   ({                                                                          \
 209     int __res = 0;                                                            \
 210     if ((tid) != 0)                                                           \
 211       __res = __lll_timedwait_tid (&(tid), (abstime));                        \
 212     __res;                                                                    \
 213   })
 214
 215
 216 /* Conditional variable handling.  */
 217
 218 extern void __lll_cond_wait (pthread_cond_t *cond)
 219      attribute_hidden;
 220 extern int __lll_cond_timedwait (pthread_cond_t *cond,
 221                                  const struct timespec *abstime)
 222      attribute_hidden;
 223 extern void __lll_cond_wake (pthread_cond_t *cond)
 224      attribute_hidden;
 225 extern void __lll_cond_broadcast (pthread_cond_t *cond)
 226      attribute_hidden;
 227
 228 #define lll_cond_wait(cond) \
 229   __lll_cond_wait (cond)
 230 #define lll_cond_timedwait(cond, abstime) \
 231   __lll_cond_timedwait (cond, abstime)
 232 #define lll_cond_wake(cond) \
 233   __lll_cond_wake (cond)
 234 #define lll_cond_broadcast(cond) \
 235   __lll_cond_broadcast (cond)
 236
 237 #endif  /* lowlevellock.h */