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Diffstat (limited to 'sysdeps/sparc/sparc32/bits/atomic.h')
| -rw-r--r-- | sysdeps/sparc/sparc32/bits/atomic.h | 75 |
1 files changed, 75 insertions, 0 deletions
diff --git a/sysdeps/sparc/sparc32/bits/atomic.h b/sysdeps/sparc/sparc32/bits/atomic.h new file mode 100644 index 0000000000..c4e0abfe06 --- /dev/null +++ b/sysdeps/sparc/sparc32/bits/atomic.h @@ -0,0 +1,75 @@ +/* Atomic operations. sparc32 version. + Copyright (C) 2003 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Jakub Jelinek <jakub@redhat.com>, 2003. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, write to the Free + Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA + 02111-1307 USA. */ + +#ifndef _BITS_ATOMIC_H +#define _BITS_ATOMIC_H 1 + +/* We have no compare and swap, just test and set. + The following implementation contends on one single global lock + per library and assumes no variable will be accessed using atomic.h + macros from two different libraries. */ + +volatile unsigned char __sparc32_atomic_lock + __attribute__ ((nocommon, section (".gnu.linkonce.b.__sparc32_atomic_lock"), + visibility ("hidden"))); + +#define __sparc32_atomic_do_lock() \ + do \ + { \ + unsigned int __old_lock; \ + do \ + __asm ("ldstub %1, %0" \ + : "=r" (__old_lock), "=m" (__sparc32_atomic_lock) \ + : "m" (__sparc32_atomic_lock)); \ + while (__old_lock); \ + } \ + while (0) + +#define __sparc32_atomic_do_unlock() \ + do __sparc32_atomic_lock = 0; while (0) + +/* The only basic operation needed is compare and exchange. */ +#define atomic_compare_and_exchange_val_acq(mem, newval, oldval) \ + ({ __typeof (mem) __acev_memp = (mem); \ + __typeof (*mem) __acev_ret; \ + __typeof (*mem) __acev_newval = (newval); \ + \ + __sparc32_atomic_do_lock (); \ + __acev_ret = *__acev_memp; \ + if (__acev_ret == (oldval)) \ + *__acev_memp = __acev_newval; \ + __sparc32_atomic_do_unlock (); \ + __acev_ret; }) + +#define atomic_compare_and_exchange_bool_acq(mem, newval, oldval) \ + ({ __typeof (mem) __aceb_memp = (mem); \ + int __aceb_ret; \ + __typeof (*mem) __aceb_newval = (newval); \ + \ + __sparc32_atomic_do_lock (); \ + __aceb_ret = 0; \ + if (*__aceb_memp == (oldval)) \ + *__aceb_memp = __aceb_newval; \ + else \ + __aceb_ret = 1; \ + __sparc32_atomic_do_unlock (); \ + __aceb_ret; }) + +#endif /* bits/atomic.h */ |