90 lines
2.9 KiB
C
90 lines
2.9 KiB
C
/* Copyright (C) 2005-2021 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 out0 asm ("out0") = (long) addr;
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register long out1 asm ("out1") = op;
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register long out2 asm ("out2") = val;
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register long out3 asm ("out3") = 0;
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register long r8 asm ("r8");
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register long r10 asm ("r10");
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register long r15 asm ("r15") = SYS_futex;
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__asm __volatile ("break 0x100000"
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: "=r"(r15), "=r"(out0), "=r"(out1), "=r"(out2), "=r"(out3),
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"=r"(r8), "=r"(r10)
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: "r"(r15), "r"(out0), "r"(out1), "r"(out2), "r"(out3)
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: "memory", "out4", "out5", "out6", "out7",
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/* Non-stacked integer registers, minus r8, r10, r12, r15. */
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"r2", "r3", "r9", "r11", "r13", "r14", "r16", "r17", "r18",
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"r19", "r20", "r21", "r22", "r23", "r24", "r25", "r26", "r27",
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"r28", "r29", "r30", "r31",
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/* Predicate registers. */
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"p6", "p7", "p8", "p9", "p10", "p11", "p12", "p13", "p14", "p15",
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/* Non-rotating fp registers. */
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"f6", "f7", "f8", "f9", "f10", "f11", "f12", "f13", "f14", "f15",
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/* Branch registers. */
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"b6");
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return r8 & r10;
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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 ("hint @pause" : : : "memory");
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}
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