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85 lines
2.5 KiB
C
85 lines
2.5 KiB
C
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/* Machine-dependent pthreads configuration and inline functions.
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powerpc version.
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Copyright (C) 1996, 1997 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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Contributed 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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/* These routines are from Appendix G of the 'PowerPC 601 RISC Microprocessor
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User's Manual', by IBM and Motorola. */
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/* For multiprocessor systems, we want to ensure all memory accesses
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are completed before we reset a lock. */
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#if 0
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/* on non multiprocessor systems, you can just: */
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#define sync() /* nothing */
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#else
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#define sync() __asm__ __volatile__ ("sync")
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#endif
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/* Spinlock implementation; required. */
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extern inline int
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testandset (int *spinlock)
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{
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int ret;
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sync();
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__asm__ __volatile__(
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"0: lwarx %0,0,%1 ;"
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" cmpwi %0,0;"
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" bne 1f;"
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" stwcx. %2,0,%1;"
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" bne- 0b;"
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"1: "
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: "=&r"(ret)
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: "r"(spinlock), "r"(1)
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: "cr0", "memory");
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sync();
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return ret != 0;
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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__ ("r1");
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/* Compare-and-swap for semaphores. */
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/* note that test-and-set(x) is the same as compare-and-swap(x, 0, 1) */
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#define HAS_COMPARE_AND_SWAP
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extern inline int
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__compare_and_swap (int *p, int oldval, int newval)
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{
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int ret;
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sync();
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__asm__ __volatile__(
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"0: lwarx %0,0,%1 ;"
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" xor. %0,%3,%0;"
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" bne 1f;"
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" stwcx. %2,0,%1;"
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" bne- 0b;"
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"1: "
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: "=&r"(ret)
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: "r"(p), "r"(newval), "r"(oldval)
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: "cr0", "memory");
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sync();
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return ret == 0;
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}
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