glibc/sysdeps/arm/bits/atomic.h
Daniel Jacobowitz b4900b98dc * sysdeps/arm/atomicity.h: Delete.
* sysdeps/arm/bits/atomic.h: New file.
2005-10-05 20:14:10 +00:00

102 lines
3.7 KiB
C

/* Copyright (C) 2002, 2003, 2004, 2005 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, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
#include <stdint.h>
#include <sysdep.h>
typedef int8_t atomic8_t;
typedef uint8_t uatomic8_t;
typedef int_fast8_t atomic_fast8_t;
typedef uint_fast8_t uatomic_fast8_t;
typedef int32_t atomic32_t;
typedef uint32_t uatomic32_t;
typedef int_fast32_t atomic_fast32_t;
typedef uint_fast32_t uatomic_fast32_t;
typedef intptr_t atomicptr_t;
typedef uintptr_t uatomicptr_t;
typedef intmax_t atomic_max_t;
typedef uintmax_t uatomic_max_t;
void __arm_link_error (void);
#define atomic_exchange_acq(mem, newvalue) \
({ __typeof (*mem) result; \
if (sizeof (*mem) == 1) \
__asm__ __volatile__ ("swpb %0, %1, [%2]" \
: "=&r,&r" (result) \
: "r,0" (newvalue), "r,r" (mem) : "memory"); \
else if (sizeof (*mem) == 4) \
__asm__ __volatile__ ("swp %0, %1, [%2]" \
: "=&r,&r" (result) \
: "r,0" (newvalue), "r,r" (mem) : "memory"); \
else \
{ \
result = 0; \
abort (); \
} \
result; })
/* Atomic compare and exchange. These sequences are not actually atomic;
there is a race if *MEM != OLDVAL and we are preempted between the two
swaps. However, they are very close to atomic, and are the best that a
pre-ARMv6 implementation can do without operating system support.
LinuxThreads has been using these sequences for many years. */
#define __arch_compare_and_exchange_val_8_acq(mem, newval, oldval) \
({ __typeof (oldval) result, tmp; \
__asm__ ("\n" \
"0:\tldr\t%1,[%2]\n\t" \
"cmp\t%1,%4\n\t" \
"movne\t%0,%1\n\t" \
"bne\t1f\n\t" \
"swpb\t%0,%3,[%2]\n\t" \
"cmp\t%1,%0\n\t" \
"swpbne\t%1,%0,[%2]\n\t" \
"bne\t0b\n\t" \
"1:" \
: "=&r" (result), "=&r" (tmp) \
: "r" (mem), "r" (newval), "r" (oldval) \
: "cc", "memory"); \
result; })
#define __arch_compare_and_exchange_val_16_acq(mem, newval, oldval) \
({ __arm_link_error (); oldval; })
#define __arch_compare_and_exchange_val_32_acq(mem, newval, oldval) \
({ __typeof (oldval) result, tmp; \
__asm__ ("\n" \
"0:\tldr\t%1,[%2]\n\t" \
"cmp\t%1,%4\n\t" \
"movne\t%0,%1\n\t" \
"bne\t1f\n\t" \
"swp\t%0,%3,[%2]\n\t" \
"cmp\t%1,%0\n\t" \
"swpne\t%1,%0,[%2]\n\t" \
"bne\t0b\n\t" \
"1:" \
: "=&r" (result), "=&r" (tmp) \
: "r" (mem), "r" (newval), "r" (oldval) \
: "cc", "memory"); \
result; })
#define __arch_compare_and_exchange_val_64_acq(mem, newval, oldval) \
({ __arm_link_error (); oldval; })