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 #define FUTEX_LOCK_PI           6
  39 #define FUTEX_UNLOCK_PI         7
  40 #define FUTEX_TRYLOCK_PI        8
  41
  42 /* Initializer for compatibility lock.  */
  43 #define LLL_MUTEX_LOCK_INITIALIZER (0)
  44
  45 #define lll_futex_wait(futexp, val) \
  46   ({                                                                          \
  47     INTERNAL_SYSCALL_DECL (__err);                                            \
  48     long int __ret;                                                           \
  49                                                                               \
  50     __ret = INTERNAL_SYSCALL (futex, __err, 4,                                \
  51                               (futexp), FUTEX_WAIT, (val), 0);                \
  52     INTERNAL_SYSCALL_ERROR_P (__ret, __err) ? -__ret : __ret;                 \
  53   })
  54
  55 #define lll_futex_timed_wait(futexp, val, timespec) \
  56   ({                                                                          \
  57     INTERNAL_SYSCALL_DECL (__err);                                            \
  58     long int __ret;                                                           \
  59                                                                               \
  60     __ret = INTERNAL_SYSCALL (futex, __err, 4,                                \
  61                               (futexp), FUTEX_WAIT, (val), (timespec));       \
  62     INTERNAL_SYSCALL_ERROR_P (__ret, __err) ? -__ret : __ret;                 \
  63   })
  64
  65 #define lll_futex_wake(futexp, nr) \
  66   ({                                                                          \
  67     INTERNAL_SYSCALL_DECL (__err);                                            \
  68     long int __ret;                                                           \
  69                                                                               \
  70     __ret = INTERNAL_SYSCALL (futex, __err, 4,                                \
  71                               (futexp), FUTEX_WAKE, (nr), 0);                 \
  72     INTERNAL_SYSCALL_ERROR_P (__ret, __err) ? -__ret : __ret;                 \
  73   })
  74
  75 #define lll_robust_mutex_dead(futexv) \
  76   do                                                                          \
  77     {                                                                         \
  78       INTERNAL_SYSCALL_DECL (__err);                                          \
  79       int *__futexp = &(futexv);                                              \
  80                                                                               \
  81       atomic_or (__futexp, FUTEX_OWNER_DIED);                                 \
  82       INTERNAL_SYSCALL (futex, __err, 4, __futexp, FUTEX_WAKE, 1, 0);         \
  83     }                                                                         \
  84   while (0)
  85
  86 /* Returns non-zero if error happened, zero if success.  */
  87 #define lll_futex_requeue(futexp, nr_wake, nr_move, mutex, val) \
  88   ({                                                                          \
  89     INTERNAL_SYSCALL_DECL (__err);                                            \
  90     long int __ret;                                                           \
  91                                                                               \
  92     __ret = INTERNAL_SYSCALL (futex, __err, 6,                                \
  93                               (futexp), FUTEX_CMP_REQUEUE, (nr_wake),         \
  94                               (nr_move), (mutex), (val));                     \
  95     INTERNAL_SYSCALL_ERROR_P (__ret, __err);                                  \
  96   })
  97
  98 /* Returns non-zero if error happened, zero if success.  */
  99 #define lll_futex_wake_unlock(futexp, nr_wake, nr_wake2, futexp2) \
 100   ({                                                                          \
 101     INTERNAL_SYSCALL_DECL (__err);                                            \
 102     long int __ret;                                                           \
 103                                                                               \
 104     __ret = INTERNAL_SYSCALL (futex, __err, 6,                                \
 105                               (futexp), FUTEX_WAKE_OP, (nr_wake),             \
 106                               (nr_wake2), (futexp2),                          \
 107                               FUTEX_OP_CLEAR_WAKE_IF_GT_ONE);                 \
 108     INTERNAL_SYSCALL_ERROR_P (__ret, __err);                                  \
 109   })
 110
 111 #ifdef UP
 112 # define __lll_acq_instr        ""
 113 # define __lll_rel_instr        ""
 114 #else
 115 # define __lll_acq_instr        "isync"
 116 # ifdef _ARCH_PWR4
 117 /*
 118  * Newer powerpc64 processors support the new "light weight" sync (lwsync)
 119  * So if the build is using -mcpu=[power4,power5,power5+,970] we can
 120  * safely use lwsync.
 121  */
 122 #  define __lll_rel_instr       "lwsync"
 123 # else
 124 /*
 125  * Older powerpc32 processors don't support the new "light weight"
 126  * sync (lwsync).  So the only safe option is to use normal sync
 127  * for all powerpc32 applications.
 128  */
 129 #  define __lll_rel_instr       "sync"
 130 # endif
 131 #endif
 132
 133 /* Set *futex to ID if it is 0, atomically.  Returns the old value */
 134 #define __lll_robust_trylock(futex, id) \
 135   ({ int __val;                                                               \
 136      __asm __volatile ("1:      lwarx   %0,0,%2\n"                            \
 137                        "        cmpwi   0,%0,0\n"                             \
 138                        "        bne     2f\n"                                 \
 139                        "        stwcx.  %3,0,%2\n"                            \
 140                        "        bne-    1b\n"                                 \
 141                        "2:      " __lll_acq_instr                             \
 142                        : "=&r" (__val), "=m" (*futex)                         \
 143                        : "r" (futex), "r" (id), "m" (*futex)                  \
 144                        : "cr0", "memory");                                    \
 145      __val;                                                                   \
 146   })
 147
 148 #define lll_robust_mutex_trylock(lock, id) __lll_robust_trylock (&(lock), id)
 149
 150 /* Set *futex to 1 if it is 0, atomically.  Returns the old value */
 151 #define __lll_trylock(futex) __lll_robust_trylock (futex, 1)
 152
 153 #define lll_mutex_trylock(lock) __lll_trylock (&(lock))
 154
 155 /* Set *futex to 2 if it is 0, atomically.  Returns the old value */
 156 #define __lll_cond_trylock(futex) __lll_robust_trylock (futex, 2)
 157
 158 #define lll_mutex_cond_trylock(lock)    __lll_cond_trylock (&(lock))
 159
 160
 161 extern void __lll_lock_wait (int *futex) attribute_hidden;
 162 extern int __lll_robust_lock_wait (int *futex) attribute_hidden;
 163
 164 #define lll_mutex_lock(lock) \
 165   (void) ({                                                                   \
 166     int *__futex = &(lock);                                                   \
 167     if (__builtin_expect (atomic_compare_and_exchange_val_acq (__futex, 1, 0),\
 168                           0) != 0)                                            \
 169       __lll_lock_wait (__futex);                                              \
 170   })
 171
 172 #define lll_robust_mutex_lock(lock, id) \
 173   ({                                                                          \
 174     int *__futex = &(lock);                                                   \
 175     int __val = 0;                                                            \
 176     if (__builtin_expect (atomic_compare_and_exchange_bool_acq (__futex, id,  \
 177                                                                 0), 0))       \
 178       __val = __lll_robust_lock_wait (__futex);                               \
 179     __val;                                                                    \
 180   })
 181
 182 #define lll_mutex_cond_lock(lock) \
 183   (void) ({                                                                   \
 184     int *__futex = &(lock);                                                   \
 185     if (__builtin_expect (atomic_compare_and_exchange_val_acq (__futex, 2, 0),\
 186                           0) != 0)                                            \
 187       __lll_lock_wait (__futex);                                              \
 188   })
 189
 190 #define lll_robust_mutex_cond_lock(lock, id) \
 191   ({                                                                          \
 192     int *__futex = &(lock);                                                   \
 193     int __val = 0;                                                            \
 194     int __id = id | FUTEX_WAITERS;                                            \
 195     if (__builtin_expect (atomic_compare_and_exchange_bool_acq (__futex, __id,\
 196                                                                 0), 0))       \
 197       __val = __lll_robust_lock_wait (__futex);                               \
 198     __val;                                                                    \
 199   })
 200
 201
 202 extern int __lll_timedlock_wait
 203   (int *futex, const struct timespec *) attribute_hidden;
 204 extern int __lll_robust_timedlock_wait
 205   (int *futex, const struct timespec *) attribute_hidden;
 206
 207 #define lll_mutex_timedlock(lock, abstime) \
 208   ({                                                                          \
 209     int *__futex = &(lock);                                                   \
 210     int __val = 0;                                                            \
 211     if (__builtin_expect (atomic_compare_and_exchange_val_acq (__futex, 1, 0),\
 212                           0) != 0)                                            \
 213       __val = __lll_timedlock_wait (__futex, abstime);                        \
 214     __val;                                                                    \
 215   })
 216
 217 #define lll_robust_mutex_timedlock(lock, abstime, id) \
 218   ({                                                                          \
 219     int *__futex = &(lock);                                                   \
 220     int __val = 0;                                                            \
 221     if (__builtin_expect (atomic_compare_and_exchange_bool_acq (__futex, id,  \
 222                                                                 0), 0))       \
 223       __val = __lll_robust_timedlock_wait (__futex, abstime);                 \
 224     __val;                                                                    \
 225   })
 226
 227 #define lll_mutex_unlock(lock) \
 228   ((void) ({                                                                  \
 229     int *__futex = &(lock);                                                   \
 230     int __val = atomic_exchange_rel (__futex, 0);                             \
 231     if (__builtin_expect (__val > 1, 0))                                      \
 232       lll_futex_wake (__futex, 1);                                            \
 233   }))
 234
 235 #define lll_robust_mutex_unlock(lock) \
 236   ((void) ({                                                                  \
 237     int *__futex = &(lock);                                                   \
 238     int __val = atomic_exchange_rel (__futex, 0);                             \
 239     if (__builtin_expect (__val & FUTEX_WAITERS, 0))                          \
 240       lll_futex_wake (__futex, 1);                                            \
 241   }))
 242
 243 #define lll_mutex_unlock_force(lock) \
 244   ((void) ({                                                                  \
 245     int *__futex = &(lock);                                                   \
 246     *__futex = 0;                                                             \
 247     __asm __volatile (__lll_rel_instr ::: "memory");                          \
 248     lll_futex_wake (__futex, 1);                                              \
 249   }))
 250
 251 #define lll_mutex_islocked(futex) \
 252   (futex != 0)
 253
 254
 255 /* Our internal lock implementation is identical to the binary-compatible
 256    mutex implementation. */
 257
 258 /* Type for lock object.  */
 259 typedef int lll_lock_t;
 260
 261 /* Initializers for lock.  */
 262 #define LLL_LOCK_INITIALIZER            (0)
 263 #define LLL_LOCK_INITIALIZER_LOCKED     (1)
 264
 265 extern int lll_unlock_wake_cb (int *__futex) attribute_hidden;
 266
 267 /* The states of a lock are:
 268     0  -  untaken
 269     1  -  taken by one user
 270    >1  -  taken by more users */
 271
 272 #define lll_trylock(lock)       lll_mutex_trylock (lock)
 273 #define lll_lock(lock)          lll_mutex_lock (lock)
 274 #define lll_unlock(lock)        lll_mutex_unlock (lock)
 275 #define lll_islocked(lock)      lll_mutex_islocked (lock)
 276
 277 /* The kernel notifies a process which uses CLONE_CLEARTID via futex
 278    wakeup when the clone terminates.  The memory location contains the
 279    thread ID while the clone is running and is reset to zero
 280    afterwards.  */
 281 #define lll_wait_tid(tid) \
 282   do {                                                                        \
 283     __typeof (tid) __tid;                                                     \
 284     while ((__tid = (tid)) != 0)                                              \
 285       lll_futex_wait (&(tid), __tid);                                         \
 286   } while (0)
 287
 288 extern int __lll_timedwait_tid (int *, const struct timespec *)
 289      attribute_hidden;
 290
 291 #define lll_timedwait_tid(tid, abstime) \
 292   ({                                                                          \
 293     int __res = 0;                                                            \
 294     if ((tid) != 0)                                                           \
 295       __res = __lll_timedwait_tid (&(tid), (abstime));                        \
 296     __res;                                                                    \
 297   })
 298
 299
 300 /* Conditional variable handling.  */
 301
 302 extern void __lll_cond_wait (pthread_cond_t *cond)
 303      attribute_hidden;
 304 extern int __lll_cond_timedwait (pthread_cond_t *cond,
 305                                  const struct timespec *abstime)
 306      attribute_hidden;
 307 extern void __lll_cond_wake (pthread_cond_t *cond)
 308      attribute_hidden;
 309 extern void __lll_cond_broadcast (pthread_cond_t *cond)
 310      attribute_hidden;
 311
 312 #define lll_cond_wait(cond) \
 313   __lll_cond_wait (cond)
 314 #define lll_cond_timedwait(cond, abstime) \
 315   __lll_cond_timedwait (cond, abstime)
 316 #define lll_cond_wake(cond) \
 317   __lll_cond_wake (cond)
 318 #define lll_cond_broadcast(cond) \
 319   __lll_cond_broadcast (cond)
 320
 321 #endif  /* lowlevellock.h */