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/* Machine-dependent pthreads configuration and inline functions.
Copyright (C) 1996, 1997, 1998 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ralf Baechle <ralf@gnu.ai.mit.edu>.
Based on the Alpha version by Richard Henderson <rth@tamu.edu>.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 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
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If
not, write to the Free Software Foundation, Inc.,
59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
TODO: This version makes use of MIPS ISA 2 features. It won't
work on ISA 1. These machines will have to take the overhead of
a sysmips(MIPS_ATOMIC_SET, ...) syscall which isn't implemented
yet correctly. There is however a better solution for R3000
uniprocessor machines possible. */
#ifndef PT_EI
# define PT_EI extern inline
#endif
/* Spinlock implementation; required. */
PT_EI long int
testandset (int *spinlock)
{
long int ret, temp;
__asm__ __volatile__(
"# Inline spinlock test & set\n\t"
".set\tmips2\n"
"1:\tll\t%0,%3\n\t"
"bnez\t%0,2f\n\t"
".set\tnoreorder\n\t"
"li\t%1,1\n\t"
".set\treorder\n\t"
"sc\t%1,%2\n\t"
"beqz\t%1,1b\n"
"2:\t.set\tmips0\n\t"
"/* End spinlock test & set */"
: "=&r"(ret), "=&r" (temp), "=m"(*spinlock)
: "m"(*spinlock)
: "memory");
return ret;
}
/* Get some notion of the current stack. Need not be exactly the top
of the stack, just something somewhere in the current frame. */
#define CURRENT_STACK_FRAME stack_pointer
register char * stack_pointer __asm__ ("$29");
/* Compare-and-swap for semaphores. */
#define HAS_COMPARE_AND_SWAP
PT_EI int
__compare_and_swap (long int *p, long int oldval, long int newval)
{
long ret;
__asm__ __volatile__ (
"/* Inline compare & swap */\n\t"
".set\tmips2\n"
"1:\tll\t%0,%4\n\t"
".set\tnoreorder\n\t"
"bne\t%0,%2,2f\n\t"
"move\t%0,%3\n\t"
".set\treorder\n\t"
"sc\t%0,%1\n\t"
"beqz\t%0,1b\n"
"2:\t.set\tmips0\n\t"
"/* End compare & swap */"
: "=&r"(ret), "=m"(*p)
: "r"(oldval), "r"(newval), "m"(*p));
return ret;
}
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