sysdeps/unix/sysv/linux/hppa/bits/atomic.h

   1 /* Copyright (C) 2003 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Carlos O'Donell <carlos@baldric.uwo.ca>, 2005.
   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 #include <stdint.h>
  21 #include <sysdep.h>
  22 #include <abort-instr.h>
  23 #include <kernel-features.h>
  24
  25 /* We need EFAULT, ENONSYS, and EAGAIN */
  26 #if !defined EFAULT && !defined ENOSYS && !defined EAGAIN
  27 #undef EFAULT
  28 #undef ENOSYS
  29 #undef EAGAIN
  30 #define EFAULT  14
  31 #define ENOSYS  251
  32 #define EAGAIN  11
  33 #endif
  34
  35 #ifndef _BITS_ATOMIC_H
  36 #define _BITS_ATOMIC_H  1
  37
  38 typedef int8_t atomic8_t;
  39 typedef uint8_t uatomic8_t;
  40 typedef int_fast8_t atomic_fast8_t;
  41 typedef uint_fast8_t uatomic_fast8_t;
  42
  43 typedef int32_t atomic32_t;
  44 typedef uint32_t uatomic32_t;
  45 typedef int_fast32_t atomic_fast32_t;
  46 typedef uint_fast32_t uatomic_fast32_t;
  47
  48 typedef intptr_t atomicptr_t;
  49 typedef uintptr_t uatomicptr_t;
  50 typedef intmax_t atomic_max_t;
  51 typedef uintmax_t uatomic_max_t;
  52
  53 /* prev = *addr;
  54    if (prev == old)
  55      *addr = new;
  56    return prev; */
  57
  58 /* Use the kernel atomic light weight syscalls on hppa */
  59 #define LWS "0xb0"
  60 #define LWS_CAS 0x0
  61 /* Note r31 is the link register */
  62 #define LWS_CLOBBER "r1", "r26", "r25", "r24", "r23", "r22", "r21", "r20", "r28", "r31", "memory"
  63 #define ASM_EAGAIN -EAGAIN
  64
  65 #if __ASSUME_LWS_CAS
  66 /* The only basic operation needed is compare and exchange.  */
  67 # define atomic_compare_and_exchange_val_acq(mem, newval, oldval)       \
  68   ({                                                                    \
  69      volatile int lws_errno = EFAULT;                                   \
  70      volatile int lws_ret = 0xdeadbeef;                                 \
  71      asm volatile(                                                      \
  72         "0:                                     \n\t"                   \
  73         "copy   %3, %%r26                       \n\t"                   \
  74         "copy   %4, %%r25                       \n\t"                   \
  75         "copy   %5, %%r24                       \n\t"                   \
  76         "ble    " LWS "(%%sr2, %%r0)            \n\t"                   \
  77         "ldi    0, %%r20                        \n\t"                   \
  78         "cmpib,=,n " ASM_EAGAIN ",%%r21,0       \n\t"                   \
  79         "nop                                    \n\t"                   \
  80         "stw    %%r28, %0                       \n\t"                   \
  81         "sub    %%r0, %%r21, %%r21              \n\t"                   \
  82         "stw    %%r21, %1                       \n\t"                   \
  83         : "=m" (lws_ret), "=m" (lws_errno), "=m" (*mem)                 \
  84         : "r" (mem), "r" (oldval), "r" (newval)                         \
  85         : LWS_CLOBBER                                                   \
  86      );                                                                 \
  87                                                                         \
  88      if(lws_errno == EFAULT || lws_errno == ENOSYS)                     \
  89         ABORT_INSTRUCTION;                                              \
  90                                                                         \
  91      lws_ret;                                                           \
  92    })
  93
  94 # define atomic_compare_and_exchange_bool_acq(mem, newval, oldval)      \
  95   ({                                                                    \
  96      int ret;                                                           \
  97      ret = atomic_compare_and_exchange_val_acq(mem, newval, oldval);    \
  98      /* Return 1 if it was already acquired */                          \
  99      (ret != oldval);                                                   \
 100    })
 101 #else
 102 /* Non-atomic primitives. */
 103 # define atomic_compare_and_exchange_val_acq(mem, newval, oldval) \
 104   ({ __typeof (mem) __gmemp = (mem);                                  \
 105      __typeof (*mem) __gret = *__gmemp;                               \
 106      __typeof (*mem) __gnewval = (newval);                            \
 107                                                                       \
 108      if (__gret == (oldval))                                          \
 109        *__gmemp = __gnewval;                                          \
 110      __gret; })
 111
 112 # define atomic_compare_and_exchange_bool_acq(mem, newval, oldval) \
 113   ({ __typeof (mem) __gmemp = (mem);                                  \
 114      __typeof (*mem) __gnewval = (newval);                            \
 115                                                                       \
 116      *__gmemp == (oldval) ? (*__gmemp = __gnewval, 0) : 1; })
 117 #endif
 118
 119 #endif  /* bits/atomic.h */
 120