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 #define FUTEX_CMP_REQUEUE       4
  34
  35 /* Initializer for compatibility lock.  */
  36 #define LLL_MUTEX_LOCK_INITIALIZER (0)
  37
  38 #define lll_futex_wait(futexp, val) \
  39   ({                                                                          \
  40     INTERNAL_SYSCALL_DECL (__err);                                            \
  41     long int __ret;                                                           \
  42                                                                               \
  43     __ret = INTERNAL_SYSCALL (futex, __err, 4,                                \
  44                               (futexp), FUTEX_WAIT, (val), 0);                \
  45     INTERNAL_SYSCALL_ERROR_P (__ret, __err) ? -__ret : __ret;                 \
  46   })
  47
  48 #define lll_futex_timed_wait(futexp, val, timespec) \
  49   ({                                                                          \
  50     INTERNAL_SYSCALL_DECL (__err);                                            \
  51     long int __ret;                                                           \
  52                                                                               \
  53     __ret = INTERNAL_SYSCALL (futex, __err, 4,                                \
  54                               (futexp), FUTEX_WAIT, (val), (timespec));       \
  55     INTERNAL_SYSCALL_ERROR_P (__ret, __err) ? -__ret : __ret;                 \
  56   })
  57
  58 #define lll_futex_wake(futexp, nr) \
  59   ({                                                                          \
  60     INTERNAL_SYSCALL_DECL (__err);                                            \
  61     long int __ret;                                                           \
  62                                                                               \
  63     __ret = INTERNAL_SYSCALL (futex, __err, 4,                                \
  64                               (futexp), FUTEX_WAKE, (nr), 0);                 \
  65     INTERNAL_SYSCALL_ERROR_P (__ret, __err) ? -__ret : __ret;                 \
  66   })
  67
  68 /* Returns non-zero if error happened, zero if success.  */
  69 #define lll_futex_requeue(futexp, nr_wake, nr_move, mutex, val) \
  70   ({                                                                          \
  71     INTERNAL_SYSCALL_DECL (__err);                                            \
  72     long int __ret;                                                           \
  73                                                                               \
  74     __ret = INTERNAL_SYSCALL (futex, __err, 6,                                \
  75                               (futexp), FUTEX_CMP_REQUEUE, (nr_wake),         \
  76                               (nr_move), (mutex), (val));                     \
  77     INTERNAL_SYSCALL_ERROR_P (__ret, __err);                                  \
  78   })
  79
  80 #ifdef UP
  81 # define __lll_acq_instr        ""
  82 # define __lll_rel_instr        ""
  83 #else
  84 # define __lll_acq_instr        "isync"
  85 # define __lll_rel_instr        "sync"
  86 #endif
  87
  88 /* Set *futex to 1 if it is 0, atomically.  Returns the old value */
  89 #define __lll_trylock(futex) \
  90   ({ int __val;                                                               \
  91      __asm __volatile ("1:      lwarx   %0,0,%2\n"                            \
  92                        "        cmpwi   0,%0,0\n"                             \
  93                        "        bne     2f\n"                                 \
  94                        "        stwcx.  %3,0,%2\n"                            \
  95                        "        bne-    1b\n"                                 \
  96                        "2:      " __lll_acq_instr                             \
  97                        : "=&r" (__val), "=m" (*futex)                         \
  98                        : "r" (futex), "r" (1), "m" (*futex)                   \
  99                        : "cr0", "memory");                                    \
 100      __val;                                                                   \
 101   })
 102
 103 #define lll_mutex_trylock(lock) __lll_trylock (&(lock))
 104
 105 /* Set *futex to 2 if it is 0, atomically.  Returns the old value */
 106 #define __lll_cond_trylock(futex) \
 107   ({ int __val;                                                               \
 108      __asm __volatile ("1:      lwarx   %0,0,%2\n"                            \
 109                        "        cmpwi   0,%0,0\n"                             \
 110                        "        bne     2f\n"                                 \
 111                        "        stwcx.  %3,0,%2\n"                            \
 112                        "        bne-    1b\n"                                 \
 113                        "2:      " __lll_acq_instr                             \
 114                        : "=&r" (__val), "=m" (*futex)                         \
 115                        : "r" (futex), "r" (2), "m" (*futex)                   \
 116                        : "cr0", "memory");                                    \
 117      __val;                                                                   \
 118   })
 119 #define lll_mutex_cond_trylock(lock)    __lll_cond_trylock (&(lock))
 120
 121
 122 extern void __lll_lock_wait (int *futex) attribute_hidden;
 123
 124 #define lll_mutex_lock(lock) \
 125   (void) ({                                                                   \
 126     int *__futex = &(lock);                                                   \
 127     if (__builtin_expect (atomic_compare_and_exchange_val_acq (__futex, 1, 0),\
 128                           0) != 0)                                            \
 129       __lll_lock_wait (__futex);                                              \
 130   })
 131
 132 #define lll_mutex_cond_lock(lock) \
 133   (void) ({                                                                   \
 134     int *__futex = &(lock);                                                   \
 135     if (__builtin_expect (atomic_compare_and_exchange_val_acq (__futex, 2, 0),\
 136                           0) != 0)                                            \
 137       __lll_lock_wait (__futex);                                              \
 138   })
 139
 140 extern int __lll_timedlock_wait
 141   (int *futex, const struct timespec *) attribute_hidden;
 142
 143 #define lll_mutex_timedlock(lock, abstime) \
 144   ({                                                                          \
 145     int *__futex = &(lock);                                                   \
 146     int __val = 0;                                                            \
 147     if (__builtin_expect (atomic_compare_and_exchange_val_acq (__futex, 1, 0),\
 148                           0) != 0)                                            \
 149       __val = __lll_timedlock_wait (__futex, abstime);                        \
 150     __val;                                                                    \
 151   })
 152
 153 #define lll_mutex_unlock(lock) \
 154   ((void) ({                                                                  \
 155     int *__futex = &(lock);                                                   \
 156     int __val = atomic_exchange_rel (__futex, 0);                             \
 157     if (__builtin_expect (__val > 1, 0))                                      \
 158       lll_futex_wake (__futex, 1);                                            \
 159   }))
 160
 161 #define lll_mutex_unlock_force(lock) \
 162   ((void) ({                                                                  \
 163     int *__futex = &(lock);                                                   \
 164     *__futex = 0;                                                             \
 165     __asm __volatile (__lll_rel_instr ::: "memory");                          \
 166     lll_futex_wake (__futex, 1);                                              \
 167   }))
 168
 169 #define lll_mutex_islocked(futex) \
 170   (futex != 0)
 171
 172
 173 /* Our internal lock implementation is identical to the binary-compatible
 174    mutex implementation. */
 175
 176 /* Type for lock object.  */
 177 typedef int lll_lock_t;
 178
 179 /* Initializers for lock.  */
 180 #define LLL_LOCK_INITIALIZER            (0)
 181 #define LLL_LOCK_INITIALIZER_LOCKED     (1)
 182
 183 extern int lll_unlock_wake_cb (int *__futex) attribute_hidden;
 184
 185 /* The states of a lock are:
 186     0  -  untaken
 187     1  -  taken by one user
 188    >1  -  taken by more users */
 189
 190 #define lll_trylock(lock)       lll_mutex_trylock (lock)
 191 #define lll_lock(lock)          lll_mutex_lock (lock)
 192 #define lll_unlock(lock)        lll_mutex_unlock (lock)
 193 #define lll_islocked(lock)      lll_mutex_islocked (lock)
 194
 195 /* The kernel notifies a process which uses CLONE_CLEARTID via futex
 196    wakeup when the clone terminates.  The memory location contains the
 197    thread ID while the clone is running and is reset to zero
 198    afterwards.  */
 199 #define lll_wait_tid(tid) \
 200   do {                                                                        \
 201     __typeof (tid) __tid;                                                     \
 202     while ((__tid = (tid)) != 0)                                              \
 203       lll_futex_wait (&(tid), __tid);                                         \
 204   } while (0)
 205
 206 extern int __lll_timedwait_tid (int *, const struct timespec *)
 207      attribute_hidden;
 208
 209 #define lll_timedwait_tid(tid, abstime) \
 210   ({                                                                          \
 211     int __res = 0;                                                            \
 212     if ((tid) != 0)                                                           \
 213       __res = __lll_timedwait_tid (&(tid), (abstime));                        \
 214     __res;                                                                    \
 215   })
 216
 217
 218 /* Conditional variable handling.  */
 219
 220 extern void __lll_cond_wait (pthread_cond_t *cond)
 221      attribute_hidden;
 222 extern int __lll_cond_timedwait (pthread_cond_t *cond,
 223                                  const struct timespec *abstime)
 224      attribute_hidden;
 225 extern void __lll_cond_wake (pthread_cond_t *cond)
 226      attribute_hidden;
 227 extern void __lll_cond_broadcast (pthread_cond_t *cond)
 228      attribute_hidden;
 229
 230 #define lll_cond_wait(cond) \
 231   __lll_cond_wait (cond)
 232 #define lll_cond_timedwait(cond, abstime) \
 233   __lll_cond_timedwait (cond, abstime)
 234 #define lll_cond_wake(cond) \
 235   __lll_cond_wake (cond)
 236 #define lll_cond_broadcast(cond) \
 237   __lll_cond_broadcast (cond)
 238
 239 #endif  /* lowlevellock.h */