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

   1 /* Copyright (C) 2003 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
 104 extern void __lll_lock_wait (int *futex, int val) attribute_hidden;
 105
 106 #define lll_mutex_lock(lock) \
 107   (void) ({                                                                   \
 108     int *__futex = &(lock);                                                   \
 109     int __val = atomic_exchange_and_add (__futex, 1);                         \
 110     __asm __volatile (__lll_acq_instr ::: "memory");                          \
 111     if (__builtin_expect (__val != 0, 0))                                     \
 112       __lll_lock_wait (__futex, __val);                                       \
 113   })
 114
 115 #define lll_mutex_cond_lock(lock) \
 116   (void) ({                                                                   \
 117     int *__futex = &(lock);                                                   \
 118     int __val = atomic_exchange_and_add (__futex, 2);                         \
 119     __asm __volatile (__lll_acq_instr ::: "memory");                          \
 120     if (__builtin_expect (__val != 0, 0))                                     \
 121       /* Note, the val + 1 is kind of ugly here.  __lll_lock_wait will add    \
 122          1 again.  But we added 2 to the futex value so this is the right     \
 123          value which will be passed to the kernel.  */                        \
 124       __lll_lock_wait (__futex, __val + 1);                                   \
 125   })
 126
 127 extern int __lll_timedlock_wait
 128         (int *futex, int val, const struct timespec *) attribute_hidden;
 129
 130 #define lll_mutex_timedlock(lock, abstime) \
 131   ({ int *__futex = &(lock);                                                  \
 132      int __val = atomic_exchange_and_add (__futex, 1);                        \
 133      __asm __volatile (__lll_acq_instr ::: "memory");                         \
 134      if (__builtin_expect (__val != 0, 0))                                    \
 135        __val = __lll_timedlock_wait (__futex, __val, (abstime));              \
 136      __val;                                                                   \
 137   })
 138
 139 #define lll_mutex_unlock(lock) \
 140   ((void) ({                                                                  \
 141     int *__futex = &(lock);                                                   \
 142     int __val = atomic_exchange_rel (__futex, 0);                             \
 143     if (__builtin_expect (__val > 1, 0))                                      \
 144       lll_futex_wake (__futex, 1);                                            \
 145   }))
 146
 147 #define lll_mutex_unlock_force(lock) \
 148   ((void) ({                                                                  \
 149     int *__futex = &(lock);                                                   \
 150     *__futex = 0;                                                             \
 151     lll_futex_wake (__futex, 1);                                              \
 152   }))
 153
 154 #define lll_mutex_islocked(futex) \
 155   (futex != 0)
 156
 157
 158 /* Our internal lock implementation is identical to the binary-compatible
 159    mutex implementation. */
 160
 161 /* Type for lock object.  */
 162 typedef int lll_lock_t;
 163
 164 /* Initializers for lock.  */
 165 #define LLL_LOCK_INITIALIZER            (0)
 166 #define LLL_LOCK_INITIALIZER_LOCKED     (1)
 167
 168 extern int lll_unlock_wake_cb (int *__futex) attribute_hidden;
 169
 170 /* The states of a lock are:
 171     0  -  untaken
 172     1  -  taken by one user
 173    >1  -  taken by more users */
 174
 175 #define lll_trylock(lock)       lll_mutex_trylock (lock)
 176 #define lll_lock(lock)          lll_mutex_lock (lock)
 177 #define lll_unlock(lock)        lll_mutex_unlock (lock)
 178 #define lll_islocked(lock)      lll_mutex_islocked (lock)
 179
 180 /* The kernel notifies a process which uses CLONE_CLEARTID via futex
 181    wakeup when the clone terminates.  The memory location contains the
 182    thread ID while the clone is running and is reset to zero
 183    afterwards.  */
 184 #define lll_wait_tid(tid) \
 185   do {                                                                        \
 186     __typeof (tid) __tid;                                                     \
 187     while ((__tid = (tid)) != 0)                                              \
 188       lll_futex_wait (&(tid), __tid);                                         \
 189   } while (0)
 190
 191 extern int __lll_timedwait_tid (int *, const struct timespec *)
 192      attribute_hidden;
 193
 194 #define lll_timedwait_tid(tid, abstime) \
 195   ({                                                                          \
 196     int __res = 0;                                                            \
 197     if ((tid) != 0)                                                           \
 198       __res = __lll_timedwait_tid (&(tid), (abstime));                        \
 199     __res;                                                                    \
 200   })
 201
 202
 203 /* Conditional variable handling.  */
 204
 205 extern void __lll_cond_wait (pthread_cond_t *cond)
 206      attribute_hidden;
 207 extern int __lll_cond_timedwait (pthread_cond_t *cond,
 208                                  const struct timespec *abstime)
 209      attribute_hidden;
 210 extern void __lll_cond_wake (pthread_cond_t *cond)
 211      attribute_hidden;
 212 extern void __lll_cond_broadcast (pthread_cond_t *cond)
 213      attribute_hidden;
 214
 215 #define lll_cond_wait(cond) \
 216   __lll_cond_wait (cond)
 217 #define lll_cond_timedwait(cond, abstime) \
 218   __lll_cond_timedwait (cond, abstime)
 219 #define lll_cond_wake(cond) \
 220   __lll_cond_wake (cond)
 221 #define lll_cond_broadcast(cond) \
 222   __lll_cond_broadcast (cond)
 223
 224 #endif  /* lowlevellock.h */