87 lines
2.7 KiB
C
87 lines
2.7 KiB
C
/* Copyright (C) 2005-2022 Free Software Foundation, Inc.
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Contributed by Richard Henderson <rth@redhat.com>.
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This file is part of the GNU Offloading and Multi Processing Library
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(libgomp).
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Libgomp is free software; you can redistribute it and/or modify it
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under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 3, or (at your option)
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any later version.
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Libgomp is distributed in the hope that it will be useful, but WITHOUT ANY
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WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
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FOR A PARTICULAR PURPOSE. See the GNU General Public License for
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more details.
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Under Section 7 of GPL version 3, you are granted additional
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permissions described in the GCC Runtime Library Exception, version
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3.1, as published by the Free Software Foundation.
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You should have received a copy of the GNU General Public License and
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a copy of the GCC Runtime Library Exception along with this program;
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see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
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<http://www.gnu.org/licenses/>. */
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/* Provide target-specific access to the futex system call. */
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#include <sys/syscall.h>
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static inline long
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sys_futex0 (int *addr, int op, int val)
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{
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register long int r0 __asm__ ("r0");
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register long int r3 __asm__ ("r3");
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register long int r4 __asm__ ("r4");
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register long int r5 __asm__ ("r5");
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register long int r6 __asm__ ("r6");
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r0 = SYS_futex;
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r3 = (long) addr;
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r4 = op;
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r5 = val;
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r6 = 0;
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/* ??? The powerpc64 sysdep.h file clobbers ctr; the powerpc32 sysdep.h
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doesn't. It doesn't much matter for us. In the interest of unity,
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go ahead and clobber it always. */
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__asm volatile ("sc; mfcr %0"
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: "=r"(r0), "=r"(r3), "=r"(r4), "=r"(r5), "=r"(r6)
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: "r"(r0), "r"(r3), "r"(r4), "r"(r5), "r"(r6)
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: "r7", "r8", "r9", "r10", "r11", "r12",
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"cr0", "ctr", "memory");
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if (__builtin_expect (r0 & (1 << 28), 0))
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return r3;
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return 0;
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}
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static inline void
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futex_wait (int *addr, int val)
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{
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long err = sys_futex0 (addr, gomp_futex_wait, val);
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if (__builtin_expect (err == ENOSYS, 0))
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{
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gomp_futex_wait &= ~FUTEX_PRIVATE_FLAG;
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gomp_futex_wake &= ~FUTEX_PRIVATE_FLAG;
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sys_futex0 (addr, gomp_futex_wait, val);
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}
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}
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static inline void
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futex_wake (int *addr, int count)
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{
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long err = sys_futex0 (addr, gomp_futex_wake, count);
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if (__builtin_expect (err == ENOSYS, 0))
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{
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gomp_futex_wait &= ~FUTEX_PRIVATE_FLAG;
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gomp_futex_wake &= ~FUTEX_PRIVATE_FLAG;
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sys_futex0 (addr, gomp_futex_wake, count);
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}
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}
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static inline void
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cpu_relax (void)
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{
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__asm volatile ("" : : : "memory");
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}
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