glibc/sysdeps/unix/sysv/linux/hppa/bits/atomic.h
2012-03-09 23:56:38 +00:00

109 lines
3.4 KiB
C

/* Copyright (C) 2003 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Carlos O'Donell <carlos@baldric.uwo.ca>, 2005.
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/>. */
#include <stdint.h> /* Required for type definitions e.g. uint8_t. */
#include <abort-instr.h> /* Required for ABORT_INSTRUCTIUON. */
#include <kernel-features.h> /* Required for __ASSUME_LWS_CAS. */
/* We need EFAULT, ENONSYS */
#if !defined EFAULT && !defined ENOSYS
#define EFAULT 14
#define ENOSYS 251
#endif
#ifndef _BITS_ATOMIC_H
#define _BITS_ATOMIC_H 1
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;
/* prev = *addr;
if (prev == old)
*addr = new;
return prev; */
/* Use the kernel atomic light weight syscalls on hppa. */
#define _LWS "0xb0"
#define _LWS_CAS "0"
/* Note r31 is the link register. */
#define _LWS_CLOBBER "r1", "r26", "r25", "r24", "r23", "r22", "r21", "r20", "r28", "r31", "memory"
/* String constant for -EAGAIN. */
#define _ASM_EAGAIN "-11"
/* String constant for -EDEADLOCK. */
#define _ASM_EDEADLOCK "-45"
#if __ASSUME_LWS_CAS
/* The only basic operation needed is compare and exchange. */
# define atomic_compare_and_exchange_val_acq(mem, newval, oldval) \
({ \
volatile int lws_errno; \
volatile int lws_ret; \
asm volatile( \
"0: \n\t" \
"copy %2, %%r26 \n\t" \
"copy %3, %%r25 \n\t" \
"copy %4, %%r24 \n\t" \
"ble " _LWS "(%%sr2, %%r0) \n\t" \
"ldi " _LWS_CAS ", %%r20 \n\t" \
"ldi " _ASM_EAGAIN ", %%r24 \n\t" \
"cmpb,=,n %%r24, %%r21, 0b \n\t" \
"nop \n\t" \
"ldi " _ASM_EDEADLOCK ", %%r25 \n\t" \
"cmpb,=,n %%r25, %%r21, 0b \n\t" \
"nop \n\t" \
"stw %%r28, %0 \n\t" \
"sub %%r0, %%r21, %%r21 \n\t" \
"stw %%r21, %1 \n\t" \
: "=m" (lws_ret), "=m" (lws_errno) \
: "r" (mem), "r" (oldval), "r" (newval) \
: _LWS_CLOBBER \
); \
\
if(lws_errno == EFAULT || lws_errno == ENOSYS) \
ABORT_INSTRUCTION; \
\
lws_ret; \
})
# define atomic_compare_and_exchange_bool_acq(mem, newval, oldval) \
({ \
int ret; \
ret = atomic_compare_and_exchange_val_acq(mem, newval, oldval); \
/* Return 1 if it was already acquired. */ \
(ret != (int)oldval); \
})
#else
# error __ASSUME_LWS_CAS is required to build glibc.
#endif
/* __ASSUME_LWS_CAS */
#endif
/* _BITS_ATOMIC_H */