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* sysdeps/mips/pt-machine.h (MEMORY_BARRIER): Define. (__compare_and_swap): Mark as modifying memory. 2000-04-11 Andreas Jaeger <aj@suse.de> * sysdeps/mips/pt-machine.h (MEMORY_BARRIER): Define. (__compare_and_swap): Mark as modifying memory.
95 lines
2.7 KiB
C
95 lines
2.7 KiB
C
/* Machine-dependent pthreads configuration and inline functions.
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Copyright (C) 1996, 1997, 1998, 2000 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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Contributed by Ralf Baechle <ralf@gnu.org>.
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Based on the Alpha version by Richard Henderson <rth@tamu.edu>.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Library General Public License as
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published by the Free Software Foundation; either version 2 of the
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License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Library General Public License for more details.
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You should have received a copy of the GNU Library General Public
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License along with the GNU C Library; see the file COPYING.LIB. If
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not, write to the Free Software Foundation, Inc.,
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59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
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TODO: This version makes use of MIPS ISA 2 features. It won't
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work on ISA 1. These machines will have to take the overhead of
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a sysmips(MIPS_ATOMIC_SET, ...) syscall which isn't implemented
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yet correctly. There is however a better solution for R3000
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uniprocessor machines possible. */
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#ifndef PT_EI
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# define PT_EI extern inline
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#endif
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/* Memory barrier. */
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#define MEMORY_BARRIER() __asm__ ("" : : : "memory")
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/* Spinlock implementation; required. */
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PT_EI long int
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testandset (int *spinlock)
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{
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long int ret, temp;
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__asm__ __volatile__(
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"# Inline spinlock test & set\n\t"
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".set\tmips2\n"
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"1:\tll\t%0,%3\n\t"
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"bnez\t%0,2f\n\t"
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".set\tnoreorder\n\t"
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"li\t%1,1\n\t"
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".set\treorder\n\t"
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"sc\t%1,%2\n\t"
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"beqz\t%1,1b\n"
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"2:\t.set\tmips0\n\t"
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"/* End spinlock test & set */"
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: "=&r"(ret), "=&r" (temp), "=m"(*spinlock)
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: "m"(*spinlock)
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: "memory");
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return ret;
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}
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/* Get some notion of the current stack. Need not be exactly the top
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of the stack, just something somewhere in the current frame. */
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#define CURRENT_STACK_FRAME stack_pointer
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register char * stack_pointer __asm__ ("$29");
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/* Compare-and-swap for semaphores. */
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#define HAS_COMPARE_AND_SWAP
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PT_EI int
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__compare_and_swap (long int *p, long int oldval, long int newval)
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{
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long ret;
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__asm__ __volatile__ (
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"/* Inline compare & swap */\n\t"
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".set\tmips2\n"
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"1:\tll\t%0,%4\n\t"
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".set\tnoreorder\n\t"
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"bne\t%0,%2,2f\n\t"
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"move\t%0,%3\n\t"
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".set\treorder\n\t"
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"sc\t%0,%1\n\t"
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"beqz\t%0,1b\n"
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"2:\t.set\tmips0\n\t"
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"/* End compare & swap */"
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: "=&r"(ret), "=m"(*p)
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: "r"(oldval), "r"(newval), "m"(*p)
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: "memory");
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return ret;
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}
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