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/* Machine-dependent pthreads configuration and inline functions.
Xtensa version.
Copyright (C) 2007 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#ifndef _PT_MACHINE_H
#define _PT_MACHINE_H 1
#include <sys/syscall.h>
#include <asm/unistd.h>
#ifndef PT_EI
# define PT_EI extern inline __attribute__ ((gnu_inline))
#endif
#define MEMORY_BARRIER() __asm__ ("memw" : : : "memory")
#define HAS_COMPARE_AND_SWAP
extern long int testandset (int *spinlock);
extern int __compare_and_swap (long int *p, long int oldval, long int newval);
/* Spinlock implementation; required. */
PT_EI long int
testandset (int *spinlock)
{
unsigned long tmp;
__asm__ volatile (
" movi %0, 0 \n"
" wsr %0, SCOMPARE1 \n"
" movi %0, 1 \n"
" s32c1i %0, %1 \n"
: "=&a" (tmp), "+m" (*spinlock)
:: "memory"
);
return tmp;
}
PT_EI int
__compare_and_swap (long int *p, long int oldval, long int newval)
{
unsigned long tmp;
unsigned long value;
__asm__ volatile (
"1: l32i %0, %2 \n"
" bne %0, %4, 2f \n"
" wsr %0, SCOMPARE1 \n"
" mov %1, %0 \n"
" mov %0, %3 \n"
" s32c1i %0, %2 \n"
" bne %1, %0, 1b \n"
"2: \n"
: "=&a" (tmp), "=&a" (value), "+m" (*p)
: "a" (newval), "a" (oldval)
: "memory" );
return tmp == oldval;
}
/* 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 __builtin_frame_address (0)
#endif /* _PT_MACHINE_H */
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