sysdeps/powerpc/nptl/pthread_spin_lock.c

   1 /* Copyright (C) 2003-2024 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, see
  16    <https://www.gnu.org/licenses/>.  */
  17
  18 #include "pthreadP.h"
  19 #include <shlib-compat.h>
  20
  21 int
  22 __pthread_spin_lock (pthread_spinlock_t *lock)
  23 {
  24   unsigned int __tmp;
  25
  26   asm volatile (
  27        "1:      lwarx   %0,0,%1" MUTEX_HINT_ACQ "\n"
  28        "        cmpwi   0,%0,0\n"
  29        "        bne-    2f\n"
  30        "        stwcx.  %2,0,%1\n"
  31        "        bne-    2f\n"
  32                 __ARCH_ACQ_INSTR "\n"
  33        "        .subsection 1\n"
  34        "2:      lwzx    %0,0,%1\n"
  35        "        cmpwi   0,%0,0\n"
  36        "        bne     2b\n"
  37        "        b       1b\n"
  38        "        .previous"
  39        : "=&r" (__tmp)
  40        : "r" (lock), "r" (1)
  41        : "cr0", "memory");
  42   return 0;
  43 }
  44 versioned_symbol (libc, __pthread_spin_lock, pthread_spin_lock, GLIBC_2_34);
  45
  46 #if OTHER_SHLIB_COMPAT (libpthread, GLIBC_2_2, GLIBC_2_34)
  47 compat_symbol (libpthread, __pthread_spin_lock, pthread_spin_lock, GLIBC_2_2);
  48 #endif