📄 bitops.h
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/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (c) 1994 - 1997, 1999, 2000 Ralf Baechle (ralf@gnu.org)
* Copyright (c) 1999, 2000 Silicon Graphics, Inc.
*/
#ifndef _ASM_BITOPS_H
#define _ASM_BITOPS_H
#include <linux/config.h>
#include <linux/compiler.h>
#include <linux/types.h>
#include <asm/byteorder.h> /* sigh ... */
#include <asm/cpu-features.h>
#if (_MIPS_SZLONG == 32)
#define SZLONG_LOG 5
#define SZLONG_MASK 31UL
#define __LL "ll "
#define __SC "sc "
#define cpu_to_lelongp(x) cpu_to_le32p((__u32 *) (x))
#elif (_MIPS_SZLONG == 64)
#define SZLONG_LOG 6
#define SZLONG_MASK 63UL
#define __LL "lld "
#define __SC "scd "
#define cpu_to_lelongp(x) cpu_to_le64p((__u64 *) (x))
#endif
#ifdef __KERNEL__
#include <asm/interrupt.h>
#include <asm/sgidefs.h>
#include <asm/war.h>
/*
* clear_bit() doesn't provide any barrier for the compiler.
*/
#define smp_mb__before_clear_bit() smp_mb()
#define smp_mb__after_clear_bit() smp_mb()
/*
* Only disable interrupt for kernel mode stuff to keep usermode stuff
* that dares to use kernel include files alive.
*/
#define __bi_flags unsigned long flags
#define __bi_local_irq_save(x) local_irq_save(x)
#define __bi_local_irq_restore(x) local_irq_restore(x)
#else
#define __bi_flags
#define __bi_local_irq_save(x)
#define __bi_local_irq_restore(x)
#endif /* __KERNEL__ */
/*
* 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(unsigned long nr, volatile unsigned long *addr)
{
unsigned long *m = ((unsigned long *) addr) + (nr >> SZLONG_LOG);
unsigned long temp;
if (cpu_has_llsc && R10000_LLSC_WAR) {
__asm__ __volatile__(
" .set mips3 \n"
"1: " __LL "%0, %1 # set_bit \n"
" or %0, %2 \n"
" " __SC "%0, %1 \n"
" beqzl %0, 1b \n"
" .set mips0 \n"
: "=&r" (temp), "=m" (*m)
: "ir" (1UL << (nr & SZLONG_MASK)), "m" (*m));
} else if (cpu_has_llsc) {
__asm__ __volatile__(
" .set mips3 \n"
"1: " __LL "%0, %1 # set_bit \n"
" or %0, %2 \n"
" " __SC "%0, %1 \n"
" beqz %0, 1b \n"
" .set mips0 \n"
: "=&r" (temp), "=m" (*m)
: "ir" (1UL << (nr & SZLONG_MASK)), "m" (*m));
} else {
volatile unsigned long *a = addr;
unsigned long mask;
__bi_flags;
a += nr >> SZLONG_LOG;
mask = 1UL << (nr & SZLONG_MASK);
__bi_local_irq_save(flags);
*a |= mask;
__bi_local_irq_restore(flags);
}
}
/*
* __set_bit - Set a bit in memory
* @nr: the bit to set
* @addr: the address to start counting from
*
* Unlike set_bit(), this function is non-atomic and may be reordered.
* If it's called on the same region of memory simultaneously, the effect
* may be that only one operation succeeds.
*/
static inline void __set_bit(unsigned long nr, volatile unsigned long * addr)
{
unsigned long * m = ((unsigned long *) addr) + (nr >> SZLONG_LOG);
*m |= 1UL << (nr & SZLONG_MASK);
}
/*
* 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(unsigned long nr, volatile unsigned long *addr)
{
unsigned long *m = ((unsigned long *) addr) + (nr >> SZLONG_LOG);
unsigned long temp;
if (cpu_has_llsc && R10000_LLSC_WAR) {
__asm__ __volatile__(
" .set mips3 \n"
"1: " __LL "%0, %1 # clear_bit \n"
" and %0, %2 \n"
" " __SC "%0, %1 \n"
" beqzl %0, 1b \n"
" .set mips0 \n"
: "=&r" (temp), "=m" (*m)
: "ir" (~(1UL << (nr & SZLONG_MASK))), "m" (*m));
} else if (cpu_has_llsc) {
__asm__ __volatile__(
" .set mips3 \n"
"1: " __LL "%0, %1 # clear_bit \n"
" and %0, %2 \n"
" " __SC "%0, %1 \n"
" beqz %0, 1b \n"
" .set mips0 \n"
: "=&r" (temp), "=m" (*m)
: "ir" (~(1UL << (nr & SZLONG_MASK))), "m" (*m));
} else {
volatile unsigned long *a = addr;
unsigned long mask;
__bi_flags;
a += nr >> SZLONG_LOG;
mask = 1UL << (nr & SZLONG_MASK);
__bi_local_irq_save(flags);
*a &= ~mask;
__bi_local_irq_restore(flags);
}
}
/*
* __clear_bit - Clears a bit in memory
* @nr: Bit to clear
* @addr: Address to start counting from
*
* Unlike clear_bit(), this function is non-atomic and may be reordered.
* If it's called on the same region of memory simultaneously, the effect
* may be that only one operation succeeds.
*/
static inline void __clear_bit(unsigned long nr, volatile unsigned long * addr)
{
unsigned long * m = ((unsigned long *) addr) + (nr >> SZLONG_LOG);
*m &= ~(1UL << (nr & SZLONG_MASK));
}
/*
* change_bit - Toggle a bit in memory
* @nr: Bit to change
* @addr: Address to start counting from
*
* change_bit() is atomic and may not be reordered.
* Note that @nr may be almost arbitrarily large; this function is not
* restricted to acting on a single-word quantity.
*/
static inline void change_bit(unsigned long nr, volatile unsigned long *addr)
{
if (cpu_has_llsc && R10000_LLSC_WAR) {
unsigned long *m = ((unsigned long *) addr) + (nr >> SZLONG_LOG);
unsigned long temp;
__asm__ __volatile__(
" .set mips3 \n"
"1: " __LL "%0, %1 # change_bit \n"
" xor %0, %2 \n"
" " __SC "%0, %1 \n"
" beqzl %0, 1b \n"
" .set mips0 \n"
: "=&r" (temp), "=m" (*m)
: "ir" (1UL << (nr & SZLONG_MASK)), "m" (*m));
} else if (cpu_has_llsc) {
unsigned long *m = ((unsigned long *) addr) + (nr >> SZLONG_LOG);
unsigned long temp;
__asm__ __volatile__(
" .set mips3 \n"
"1: " __LL "%0, %1 # change_bit \n"
" xor %0, %2 \n"
" " __SC "%0, %1 \n"
" beqz %0, 1b \n"
" .set mips0 \n"
: "=&r" (temp), "=m" (*m)
: "ir" (1UL << (nr & SZLONG_MASK)), "m" (*m));
} else {
volatile unsigned long *a = addr;
unsigned long mask;
__bi_flags;
a += nr >> SZLONG_LOG;
mask = 1UL << (nr & SZLONG_MASK);
__bi_local_irq_save(flags);
*a ^= mask;
__bi_local_irq_restore(flags);
}
}
/*
* __change_bit - Toggle a bit in memory
* @nr: the bit to change
* @addr: the address to start counting from
*
* Unlike change_bit(), this function is non-atomic and may be reordered.
* If it's called on the same region of memory simultaneously, the effect
* may be that only one operation succeeds.
*/
static inline void __change_bit(unsigned long nr, volatile unsigned long * addr)
{
unsigned long * m = ((unsigned long *) addr) + (nr >> SZLONG_LOG);
*m ^= 1UL << (nr & SZLONG_MASK);
}
/*
* 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(unsigned long nr,
volatile unsigned long *addr)
{
if (cpu_has_llsc && R10000_LLSC_WAR) {
unsigned long *m = ((unsigned long *) addr) + (nr >> SZLONG_LOG);
unsigned long temp, res;
__asm__ __volatile__(
" .set mips3 \n"
"1: " __LL "%0, %1 # test_and_set_bit \n"
" or %2, %0, %3 \n"
" " __SC "%2, %1 \n"
" beqzl %2, 1b \n"
" and %2, %0, %3 \n"
#ifdef CONFIG_SMP
" sync \n"
#endif
" .set mips0 \n"
: "=&r" (temp), "=m" (*m), "=&r" (res)
: "r" (1UL << (nr & SZLONG_MASK)), "m" (*m)
: "memory");
return res != 0;
} else if (cpu_has_llsc) {
unsigned long *m = ((unsigned long *) addr) + (nr >> SZLONG_LOG);
unsigned long temp, res;
__asm__ __volatile__(
" .set push \n"
" .set noreorder \n"
" .set mips3 \n"
"1: " __LL "%0, %1 # test_and_set_bit \n"
" or %2, %0, %3 \n"
" " __SC "%2, %1 \n"
" beqz %2, 1b \n"
" and %2, %0, %3 \n"
#ifdef CONFIG_SMP
" sync \n"
#endif
" .set pop \n"
: "=&r" (temp), "=m" (*m), "=&r" (res)
: "r" (1UL << (nr & SZLONG_MASK)), "m" (*m)
: "memory");
return res != 0;
} else {
volatile unsigned long *a = addr;
unsigned long mask;
int retval;
__bi_flags;
a += nr >> SZLONG_LOG;
mask = 1UL << (nr & SZLONG_MASK);
__bi_local_irq_save(flags);
retval = (mask & *a) != 0;
*a |= mask;
__bi_local_irq_restore(flags);
return retval;
}
}
/*
* __test_and_set_bit - Set a bit and return its old value
* @nr: Bit to set
* @addr: Address to count from
*
* This operation is non-atomic and can be reordered.
* If two examples of this operation race, one can appear to succeed
* but actually fail. You must protect multiple accesses with a lock.
*/
static inline int __test_and_set_bit(unsigned long nr,
volatile unsigned long *addr)
{
volatile unsigned long *a = addr;
unsigned long mask;
int retval;
a += nr >> SZLONG_LOG;
mask = 1UL << (nr & SZLONG_MASK);
retval = (mask & *a) != 0;
*a |= mask;
return retval;
}
/*
* 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(unsigned long nr,
volatile unsigned long *addr)
{
if (cpu_has_llsc && R10000_LLSC_WAR) {
unsigned long *m = ((unsigned long *) addr) + (nr >> SZLONG_LOG);
unsigned long temp, res;
__asm__ __volatile__(
" .set mips3 \n"
"1: " __LL "%0, %1 # test_and_clear_bit \n"
" or %2, %0, %3 \n"
" xor %2, %3 \n"
" " __SC "%2, %1 \n"
" beqzl %2, 1b \n"
" and %2, %0, %3 \n"
#ifdef CONFIG_SMP
" sync \n"
#endif
" .set mips0 \n"
: "=&r" (temp), "=m" (*m), "=&r" (res)
: "r" (1UL << (nr & SZLONG_MASK)), "m" (*m)
: "memory");
return res != 0;
} else if (cpu_has_llsc) {
unsigned long *m = ((unsigned long *) addr) + (nr >> SZLONG_LOG);
unsigned long temp, res;
__asm__ __volatile__(
" .set push \n"
" .set noreorder \n"
" .set mips3 \n"
"1: " __LL "%0, %1 # test_and_clear_bit \n"
" or %2, %0, %3 \n"
" xor %2, %3 \n"
" " __SC "%2, %1 \n"
" beqz %2, 1b \n"
" and %2, %0, %3 \n"
#ifdef CONFIG_SMP
" sync \n"
#endif
" .set pop \n"
: "=&r" (temp), "=m" (*m), "=&r" (res)
: "r" (1UL << (nr & SZLONG_MASK)), "m" (*m)
: "memory");
return res != 0;
} else {
volatile unsigned long *a = addr;
unsigned long mask;
int retval;
__bi_flags;
a += nr >> SZLONG_LOG;
mask = 1UL << (nr & SZLONG_MASK);
__bi_local_irq_save(flags);
retval = (mask & *a) != 0;
*a &= ~mask;
__bi_local_irq_restore(flags);
return retval;
}
}
/*
* __test_and_clear_bit - Clear a bit and return its old value
* @nr: Bit to clear
* @addr: Address to count from
*
* This operation is non-atomic and can be reordered.
* If two examples of this operation race, one can appear to succeed
* but actually fail. You must protect multiple accesses with a lock.
*/
static inline int __test_and_clear_bit(unsigned long nr,
volatile unsigned long * addr)
{
volatile unsigned long *a = addr;
unsigned long mask;
int retval;
a += (nr >> SZLONG_LOG);
mask = 1UL << (nr & SZLONG_MASK);
retval = ((mask & *a) != 0);
*a &= ~mask;
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