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// Copyright 2006-2007 various authors
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 2 of the License, or
// (at your option) any later version.
//
// This program 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 General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
#ifndef RTAPI_BITOPS_H
#define RTAPI_BITOPS_H
#if (defined(__MODULE__) && !defined(SIM))
#include <asm/bitops.h>
#elif defined(__i386__)
/* From <asm/bitops.h>
* Copyright 1992, Linus Torvalds.
*/
#define LOCK_PREFIX "lock ; "
#define ADDR (*(volatile long *) addr)
/**
* set_bit - Atomically set a bit in memory
* @nr: the bit to set
* @addr: the address to start counting from
*
* This function is atomic and may not be reordered. See __set_bit()
* if you do not require the atomic guarantees.
* Note that @nr may be almost arbitrarily large; this function is not
* restricted to acting on a single-word quantity.
*/
static __inline__ void set_bit(int nr, volatile void * addr)
{
__asm__ __volatile__(
"btsl %1,%0"
:"=m" (ADDR)
:"Ir" (nr));
}
#if 0 /* Fool kernel-doc since it doesn't do macros yet */
/**
* test_bit - Determine whether a bit is set
* @nr: bit number to test
* @addr: Address to start counting from
*/
static int test_bit(int nr, const volatile void * addr);
#endif
static __inline__ int constant_test_bit(int nr, const volatile void * addr)
{
return ((1UL << (nr & 31)) & (((const volatile unsigned int *) addr)[nr >> 5])) != 0;
}
static __inline__ int variable_test_bit(int nr, volatile void * addr)
{
int oldbit;
__asm__ __volatile__(
"btl %2,%1\n\tsbbl %0,%0"
:"=r" (oldbit)
:"m" (ADDR),"Ir" (nr));
return oldbit;
}
#define test_bit(nr,addr) \
(__builtin_constant_p(nr) ? \
constant_test_bit((nr),(addr)) : \
variable_test_bit((nr),(addr)))
/**
* clear_bit - Clears a bit in memory
* @nr: Bit to clear
* @addr: Address to start counting from
*
* clear_bit() is atomic and may not be reordered. However, it does
* not contain a memory barrier, so if it is used for locking purposes,
* you should call smp_mb__before_clear_bit() and/or smp_mb__after_clear_bit()
* in order to ensure changes are visible on other processors.
*/
static __inline__ void clear_bit(int nr, volatile void * addr)
{
__asm__ __volatile__(
"btrl %1,%0"
:"=m" (ADDR)
:"Ir" (nr));
}
/**
* test_and_set_bit - Set a bit and return its old value
* @nr: Bit to set
* @addr: Address to count from
*
* This operation is atomic and cannot be reordered.
* It also implies a memory barrier.
*/
static __inline__ int test_and_set_bit(int nr, volatile void * addr)
{
int oldbit;
__asm__ __volatile__( LOCK_PREFIX
"btsl %2,%1\n\tsbbl %0,%0"
:"=r" (oldbit),"=m" (ADDR)
:"Ir" (nr) : "memory");
return oldbit;
}
/**
* test_and_clear_bit - Clear a bit and return its old value
* @nr: Bit to set
* @addr: Address to count from
*
* This operation is atomic and cannot be reordered.
* It also implies a memory barrier.
*/
static __inline__ int test_and_clear_bit(int nr, volatile void * addr)
{
int oldbit;
__asm__ __volatile__(
"btrl %2,%1\n\tsbbl %0,%0"
:"=r" (oldbit),"=m" (ADDR)
:"Ir" (nr) : "memory");
return oldbit;
}
#elif defined(__x86_64__)
/*
* Copyright 1992, Linus Torvalds.
*/
#define LOCK_PREFIX "lock ; "
#define ADDR (*(volatile long *) addr)
/**
* set_bit - Atomically set a bit in memory
* @nr: the bit to set
* @addr: the address to start counting from
*
* This function is atomic and may not be reordered. See __set_bit()
* if you do not require the atomic guarantees.
* Note that @nr may be almost arbitrarily large; this function is not
* restricted to acting on a single-word quantity.
*/
static __inline__ void set_bit(int nr, volatile void * addr)
{
__asm__ __volatile__( LOCK_PREFIX
"btsl %1,%0"
:"=m" (ADDR)
:"dIr" (nr) : "memory");
}
/**
* clear_bit - Clears a bit in memory
* @nr: Bit to clear
* @addr: Address to start counting from
*
* clear_bit() is atomic and may not be reordered. However, it does
* not contain a memory barrier, so if it is used for locking purposes,
* you should call smp_mb__before_clear_bit() and/or smp_mb__after_clear_bit()
* in order to ensure changes are visible on other processors.
*/
static __inline__ void clear_bit(int nr, volatile void * addr)
{
__asm__ __volatile__( LOCK_PREFIX
"btrl %1,%0"
:"=m" (ADDR)
:"dIr" (nr));
}
static __inline__ int constant_test_bit(int nr, const volatile void * addr)
{
return ((1UL << (nr & 31)) & (((const volatile unsigned int *) addr)[nr >> 5])) != 0;
}
static __inline__ int variable_test_bit(int nr, volatile const void * addr)
{
int oldbit;
__asm__ __volatile__(
"btl %2,%1\n\tsbbl %0,%0"
:"=r" (oldbit)
:"m" (ADDR),"dIr" (nr));
return oldbit;
}
#define test_bit(nr,addr) \
(__builtin_constant_p(nr) ? \
constant_test_bit((nr),(addr)) : \
variable_test_bit((nr),(addr)))
/**
* test_and_set_bit - Set a bit and return its old value
* @nr: Bit to set
* @addr: Address to count from
*
* This operation is atomic and cannot be reordered.
* It also implies a memory barrier.
*/
static __inline__ int test_and_set_bit(int nr, volatile void * addr)
{
int oldbit;
__asm__ __volatile__( LOCK_PREFIX
"btsl %2,%1\n\tsbbl %0,%0"
:"=r" (oldbit),"=m" (ADDR)
:"dIr" (nr) : "memory");
return oldbit;
}
/**
* test_and_clear_bit - Clear a bit and return its old value
* @nr: Bit to clear
* @addr: Address to count from
*
* This operation is atomic and cannot be reordered.
* It also implies a memory barrier.
*/
static __inline__ int test_and_clear_bit(int nr, volatile void * addr)
{
int oldbit;
__asm__ __volatile__( LOCK_PREFIX
"btrl %2,%1\n\tsbbl %0,%0"
:"=r" (oldbit),"=m" (ADDR)
:"dIr" (nr) : "memory");
return oldbit;
}
#undef ADDR
#elif defined(__powerpc__)
#define BITS_PER_LONG 32
#define BITOP_MASK(nr) (1UL << ((nr) % BITS_PER_LONG))
#define BITOP_WORD(nr) ((nr) / BITS_PER_LONG)
#ifdef CONFIG_SMP
#define ISYNC_ON_SMP "\n\tisync\n"
#define LWSYNC_ON_SMP __stringify(LWSYNC) "\n"
#else
#define ISYNC_ON_SMP
#define LWSYNC_ON_SMP
#endif
static __inline__ int test_and_set_bit(unsigned long nr,
volatile unsigned long *addr)
{
unsigned long old, t;
unsigned long mask = BITOP_MASK(nr);
unsigned long *p = ((unsigned long *)addr) + BITOP_WORD(nr);
__asm__ __volatile__(
LWSYNC_ON_SMP
"1:" "lwarx %0,0,%3 # test_and_set_bit\n"
"or %1,%0,%2 \n"
"stwcx. %1,0,%3 \n"
"bne- 1b"
ISYNC_ON_SMP
: "=&r" (old), "=&r" (t)
: "r" (mask), "r" (p)
: "cc", "memory");
return (old & mask) != 0;
}
static __inline__ int test_and_clear_bit(unsigned long nr,
volatile unsigned long *addr)
{
unsigned long old, t;
unsigned long mask = BITOP_MASK(nr);
unsigned long *p = ((unsigned long *)addr) + BITOP_WORD(nr);
__asm__ __volatile__(
LWSYNC_ON_SMP
"1:" "lwarx %0,0,%3 # test_and_clear_bit\n"
"andc %1,%0,%2 \n"
"stwcx. %1,0,%3 \n"
"bne- 1b"
ISYNC_ON_SMP
: "=&r" (old), "=&r" (t)
: "r" (mask), "r" (p)
: "cc", "memory");
return (old & mask) != 0;
}
#else
#error The header file <asm/bitops.h> is not usable and rtapi does not yet have support for your CPU
#endif
#endif
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