sysdeps/unix/sysv/linux/hppa/atomic-machine.h

   1 /* Copyright (C) 2003-2018 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, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 #include <stdint.h> /*  Required for type definitions e.g. uint8_t.  */
  20
  21 #ifndef _ATOMIC_MACHINE_H
  22 #define _ATOMIC_MACHINE_H       1
  23
  24 typedef int8_t atomic8_t;
  25 typedef uint8_t uatomic8_t;
  26 typedef int_fast8_t atomic_fast8_t;
  27 typedef uint_fast8_t uatomic_fast8_t;
  28
  29 typedef int32_t atomic32_t;
  30 typedef uint32_t uatomic32_t;
  31 typedef int_fast32_t atomic_fast32_t;
  32 typedef uint_fast32_t uatomic_fast32_t;
  33
  34 typedef intptr_t atomicptr_t;
  35 typedef uintptr_t uatomicptr_t;
  36 typedef intmax_t atomic_max_t;
  37 typedef uintmax_t uatomic_max_t;
  38
  39 #define __HAVE_64B_ATOMICS 0
  40 #define USE_ATOMIC_COMPILER_BUILTINS 0
  41
  42 /* XXX Is this actually correct?  */
  43 #define ATOMIC_EXCHANGE_USES_CAS 1
  44
  45 /* prev = *addr;
  46    if (prev == old)
  47      *addr = new;
  48    return prev; */
  49
  50 /* Use the kernel atomic light weight syscalls on hppa.  */
  51 #define _LWS "0xb0"
  52 #define _LWS_CAS "0"
  53 /* Note r31 is the link register.  */
  54 #define _LWS_CLOBBER "r1", "r23", "r22", "r20", "r31", "memory"
  55 /* String constant for -EAGAIN.  */
  56 #define _ASM_EAGAIN "-11"
  57 /* String constant for -EDEADLOCK.  */
  58 #define _ASM_EDEADLOCK "-45"
  59
  60 /* The only basic operation needed is compare and exchange.  The mem
  61    pointer must be word aligned.  We no longer loop on deadlock.  */
  62 #define atomic_compare_and_exchange_val_acq(mem, newval, oldval)        \
  63   ({                                                                    \
  64      register long lws_errno asm("r21");                                \
  65      register unsigned long lws_ret asm("r28");                         \
  66      register unsigned long lws_mem asm("r26") = (unsigned long)(mem);  \
  67      register unsigned long lws_old asm("r25") = (unsigned long)(oldval);\
  68      register unsigned long lws_new asm("r24") = (unsigned long)(newval);\
  69      __asm__ __volatile__(                                              \
  70         "0:                                     \n\t"                   \
  71         "ble    " _LWS "(%%sr2, %%r0)           \n\t"                   \
  72         "ldi    " _LWS_CAS ", %%r20             \n\t"                   \
  73         "cmpiclr,<> " _ASM_EAGAIN ", %%r21, %%r0\n\t"                   \
  74         "b,n 0b                                 \n\t"                   \
  75         "cmpclr,= %%r0, %%r21, %%r0             \n\t"                   \
  76         "iitlbp %%r0,(%%sr0, %%r0)              \n\t"                   \
  77         : "=r" (lws_ret), "=r" (lws_errno)                              \
  78         : "r" (lws_mem), "r" (lws_old), "r" (lws_new)                   \
  79         : _LWS_CLOBBER                                                  \
  80      );                                                                 \
  81                                                                         \
  82      (__typeof (oldval)) lws_ret;                                       \
  83    })
  84
  85 #define atomic_compare_and_exchange_bool_acq(mem, newval, oldval)       \
  86   ({                                                                    \
  87      __typeof__ (*mem) ret;                                             \
  88      ret = atomic_compare_and_exchange_val_acq(mem, newval, oldval);    \
  89      /* Return 1 if it was already acquired.  */                        \
  90      (ret != oldval);                                                   \
  91    })
  92
  93 #endif
  94 /* _ATOMIC_MACHINE_H */