glibc/sysdeps/powerpc/powerpc64/bits/atomic.h

136 lines
4.9 KiB
C

/* Atomic operations. PowerPC64 version.
Copyright (C) 2003 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Paul Mackerras <paulus@au.ibm.com>, 2003.
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, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
/*
* The 32-bit exchange_bool is different on powerpc64 because the subf
* does signed 64-bit arthmatic while the lwarx is 32-bit unsigned
* (a load word and zero (high 32) form) load.
* In powerpc64 register values are 64-bit by default, including oldval.
* Net we need to extend sign word the result of lwarx to 64-bit so the
* 64-bit subtract from gives the expected result and sets the condition
* correctly.
*/
# define __arch_compare_and_exchange_bool_32_acq(mem, newval, oldval) \
({ \
unsigned int __tmp; \
__asm __volatile (__ARCH_REL_INSTR "\n" \
"1: lwarx %0,0,%1\n" \
" extsw %0,%0\n" \
" subf. %0,%2,%0\n" \
" bne 2f\n" \
" stwcx. %3,0,%1\n" \
" bne- 1b\n" \
"2: " __ARCH_ACQ_INSTR \
: "=&r" (__tmp) \
: "b" (mem), "r" (oldval), "r" (newval) \
: "cr0", "memory"); \
__tmp != 0; \
})
/*
* Only powerpc64 processors support Load doubleword and reserve index (ldarx)
* and Store doubleword conditional indexed (stdcx) instructions. So here
* we define the 64-bit forms.
*/
# define __arch_compare_and_exchange_bool_64_acq(mem, newval, oldval) \
({ \
unsigned long __tmp; \
__asm __volatile (__ARCH_REL_INSTR "\n" \
"1: ldarx %0,0,%1\n" \
" subf. %0,%2,%0\n" \
" bne 2f\n" \
" stdcx. %3,0,%1\n" \
" bne- 1b\n" \
"2: " __ARCH_ACQ_INSTR \
: "=&r" (__tmp) \
: "b" (mem), "r" (oldval), "r" (newval) \
: "cr0", "memory"); \
__tmp != 0; \
})
#define __arch_compare_and_exchange_val_64_acq(mem, newval, oldval) \
({ \
__typeof (*(mem)) __tmp; \
__typeof (mem) __memp = (mem); \
__asm __volatile (__ARCH_REL_INSTR "\n" \
"1: ldarx %0,0,%1\n" \
" cmpd %0,%2\n" \
" bne 2f\n" \
" stdcx. %3,0,%1\n" \
" bne- 1b\n" \
"2: " __ARCH_ACQ_INSTR \
: "=&r" (__tmp) \
: "b" (__memp), "r" (oldval), "r" (newval) \
: "cr0", "memory"); \
__tmp; \
})
# define __arch_atomic_exchange_64(mem, value) \
({ \
__typeof (*mem) __val; \
__asm __volatile (__ARCH_REL_INSTR "\n" \
"1: ldarx %0,0,%2\n" \
" stdcx. %3,0,%2\n" \
" bne- 1b" \
: "=&r" (__val), "=m" (*mem) \
: "b" (mem), "r" (value), "1" (*mem) \
: "cr0"); \
__val; \
})
# define __arch_atomic_exchange_and_add_64(mem, value) \
({ \
__typeof (*mem) __val, __tmp; \
__asm __volatile ("1: ldarx %0,0,%3\n" \
" add %1,%0,%4\n" \
" stdcx. %1,0,%3\n" \
" bne- 1b" \
: "=&b" (__val), "=&r" (__tmp), "=m" (*mem) \
: "b" (mem), "r" (value), "2" (*mem) \
: "cr0"); \
__val; \
})
# define __arch_atomic_decrement_if_positive_64(mem) \
({ int __val, __tmp; \
__asm __volatile ("1: ldarx %0,0,%3\n" \
" cmpdi 0,%0,0\n" \
" addi %1,%0,-1\n" \
" ble 2f\n" \
" stdcx. %1,0,%3\n" \
" bne- 1b\n" \
"2: " __ARCH_ACQ_INSTR \
: "=&b" (__val), "=&r" (__tmp), "=m" (*mem) \
: "b" (mem), "2" (*mem) \
: "cr0"); \
__val; \
})
/*
* All powerpc64 processors support the new "light weight" sync (lwsync).
*/
# define atomic_read_barrier() __asm ("lwsync" ::: "memory")
/*
* Include the rest of the atomic ops macros which are common to both
* powerpc32 and powerpc64.
*/
#include_next <bits/atomic.h>