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 */
  26 #if !defined EFAULT && !defined ENOSYS
  27 #define EFAULT  14
  28 #define ENOSYS  251
  29 #endif
  30
  31 #ifndef _BITS_ATOMIC_H
  32 #define _BITS_ATOMIC_H  1
  33
  34 typedef int8_t atomic8_t;
  35 typedef uint8_t uatomic8_t;
  36 typedef int_fast8_t atomic_fast8_t;
  37 typedef uint_fast8_t uatomic_fast8_t;
  38
  39 typedef int32_t atomic32_t;
  40 typedef uint32_t uatomic32_t;
  41 typedef int_fast32_t atomic_fast32_t;
  42 typedef uint_fast32_t uatomic_fast32_t;
  43
  44 typedef intptr_t atomicptr_t;
  45 typedef uintptr_t uatomicptr_t;
  46 typedef intmax_t atomic_max_t;
  47 typedef uintmax_t uatomic_max_t;
  48
  49 /* prev = *addr;
  50    if (prev == old)
  51      *addr = new;
  52    return prev; */
  53
  54 /* Use the kernel atomic light weight syscalls on hppa */
  55 #define LWS "0xb0"
  56 #define LWS_CAS "0"
  57 /* Note r31 is the link register */
  58 #define LWS_CLOBBER "r1", "r26", "r25", "r24", "r23", "r22", "r21", "r20", "r28", "r31", "memory"
  59 #define ASM_EAGAIN "11"
  60
  61 #if __ASSUME_LWS_CAS
  62 /* The only basic operation needed is compare and exchange.  */
  63 # define atomic_compare_and_exchange_val_acq(mem, newval, oldval)       \
  64   ({                                                                    \
  65      volatile int lws_errno = EFAULT;                                   \
  66      volatile int lws_ret = 0xdeadbeef;                                 \
  67      asm volatile(                                                      \
  68         "0:                                     \n\t"                   \
  69         "copy   %3, %%r26                       \n\t"                   \
  70         "copy   %4, %%r25                       \n\t"                   \
  71         "copy   %5, %%r24                       \n\t"                   \
  72         "ble    " LWS "(%%sr2, %%r0)            \n\t"                   \
  73         "ldi    " LWS_CAS ", %%r20              \n\t"                   \
  74         "cmpib,=,n " ASM_EAGAIN ",%%r21,0b      \n\t"                   \
  75         "nop                                    \n\t"                   \
  76         "stw    %%r28, %0                       \n\t"                   \
  77         "sub    %%r0, %%r21, %%r21              \n\t"                   \
  78         "stw    %%r21, %1                       \n\t"                   \
  79         : "=m" (lws_ret), "=m" (lws_errno), "=m" (*mem)                 \
  80         : "r" (mem), "r" (oldval), "r" (newval)                         \
  81         : LWS_CLOBBER                                                   \
  82      );                                                                 \
  83                                                                         \
  84      if(lws_errno == EFAULT || lws_errno == ENOSYS)                     \
  85         ABORT_INSTRUCTION;                                              \
  86                                                                         \
  87      lws_ret;                                                           \
  88    })
  89
  90 # define atomic_compare_and_exchange_bool_acq(mem, newval, oldval)      \
  91   ({                                                                    \
  92      int ret;                                                           \
  93      ret = atomic_compare_and_exchange_val_acq(mem, newval, oldval);    \
  94      /* Return 1 if it was already acquired */                          \
  95      (ret != oldval);                                                   \
  96    })
  97 #else
  98 # error __ASSUME_LWS_CAS is required to build glibc.
  99 #endif
 100 /* __ASSUME_LWS_CAS */
 101
 102 #endif
 103 /* _BITS_ATOMIC_H */