1  /* Copyright (C) 2005-2023 Free Software Foundation, Inc.
       2     Contributed by Jakub Jelinek <jakub@redhat.com>.
       3  
       4     This file is part of the GNU Offloading and Multi Processing Library
       5     (libgomp).
       6  
       7     Libgomp is free software; you can redistribute it and/or modify it
       8     under the terms of the GNU General Public License as published by
       9     the Free Software Foundation; either version 3, or (at your option)
      10     any later version.
      11  
      12     Libgomp is distributed in the hope that it will be useful, but WITHOUT ANY
      13     WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
      14     FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
      15     more details.
      16  
      17     Under Section 7 of GPL version 3, you are granted additional
      18     permissions described in the GCC Runtime Library Exception, version
      19     3.1, as published by the Free Software Foundation.
      20  
      21     You should have received a copy of the GNU General Public License and
      22     a copy of the GCC Runtime Library Exception along with this program;
      23     see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
      24     <http://www.gnu.org/licenses/>.  */
      25  
      26  /* Provide target-specific access to the futex system call.  */
      27  
      28  #include <sys/syscall.h>
      29  
      30  static inline long
      31  sys_futex0 (int *addr, int op, int val)
      32  {
      33    register long int g1  __asm__ ("g1");
      34    register long int o0  __asm__ ("o0");
      35    register long int o1  __asm__ ("o1");
      36    register long int o2  __asm__ ("o2");
      37    register long int o3  __asm__ ("o3");
      38  
      39    g1 = SYS_futex;
      40    o0 = (long) addr;
      41    o1 = op;
      42    o2 = val;
      43    o3 = 0;
      44  
      45  #ifdef __arch64__
      46  # define SYSCALL_STRING "ta\t0x6d; bcs,a,pt %%xcc, 1f; sub %%g0, %%o0, %%o0; 1:"
      47  #else
      48  # define SYSCALL_STRING "ta\t0x10; bcs,a 1f; sub %%g0, %%o0, %%o0; 1:"
      49  #endif
      50  
      51    __asm volatile (SYSCALL_STRING
      52  		  : "=r" (g1), "=r" (o0)
      53  		  : "0" (g1), "1" (o0), "r" (o1), "r" (o2), "r" (o3)
      54  		  : "g2", "g3", "g4", "g5", "g6",
      55  		    "f0", "f1", "f2", "f3", "f4", "f5", "f6", "f7",
      56  		    "f8", "f9", "f10", "f11", "f12", "f13", "f14", "f15",
      57  		    "f16", "f17", "f18", "f19", "f20", "f21", "f22", "f23",
      58  		    "f24", "f25", "f26", "f27", "f28", "f29", "f30", "f31",
      59  #ifdef __arch64__
      60  		    "f32", "f34", "f36", "f38", "f40", "f42", "f44", "f46",
      61  		    "f48", "f50", "f52", "f54", "f56", "f58", "f60", "f62",
      62  #endif
      63  		    "cc", "memory");
      64    return o0;
      65  }
      66  
      67  static inline void
      68  futex_wait (int *addr, int val)
      69  {
      70    long err = sys_futex0 (addr, gomp_futex_wait, val);
      71    if (__builtin_expect (err == ENOSYS, 0))
      72      {
      73        gomp_futex_wait &= ~FUTEX_PRIVATE_FLAG;
      74        gomp_futex_wake &= ~FUTEX_PRIVATE_FLAG;
      75        sys_futex0 (addr, gomp_futex_wait, val);
      76      }
      77  }
      78  
      79  static inline void
      80  futex_wake (int *addr, int count)
      81  {
      82    long err = sys_futex0 (addr, gomp_futex_wake, count);
      83    if (__builtin_expect (err == ENOSYS, 0))
      84      {
      85        gomp_futex_wait &= ~FUTEX_PRIVATE_FLAG;
      86        gomp_futex_wake &= ~FUTEX_PRIVATE_FLAG;
      87        sys_futex0 (addr, gomp_futex_wake, count);
      88      }
      89  }
      90  
      91  static inline void
      92  cpu_relax (void)
      93  {
      94    __asm volatile ("rd %%ccr, %%g0" : : : "memory");
      95  }