/* SPDX-License-Identifier: GPL-2.0 */
/*
* Copyright 1995, Russell King.
* Various bits and pieces copyrights include:
* Linus Torvalds (test_bit).
* Big endian support: Copyright 2001, Nicolas Pitre
* reworked by rmk.
*
* bit 0 is the LSB of an "unsigned long" quantity.
*
* Please note that the code in this file should never be included
* from user space. Many of these are not implemented in assembler
* since they would be too costly. Also, they require privileged
* instructions (which are not available from user mode) to ensure
* that they are atomic.
*/
#ifndef __ASM_ARM_BITOPS_H
#define __ASM_ARM_BITOPS_H
#ifdef __KERNEL__
#ifndef _LINUX_BITOPS_H
#error only <linux/bitops.h> can be included directly
#endif
#include <linux/compiler.h>
#include <linux/irqflags.h>
#include <asm/barrier.h>
/*
* These functions are the basis of our bit ops.
*
* First, the atomic bitops. These use native endian.
*/
static inline void ____atomic_set_bit(unsigned int bit, volatile unsigned long *p)
{
unsigned long flags;
unsigned long mask = BIT_MASK(bit);
p += BIT_WORD(bit);
raw_local_irq_save(flags);
*p |= mask;
raw_local_irq_restore(flags);
}
static inline void ____atomic_clear_bit(unsigned int bit, volatile unsigned long *p)
{
unsigned long flags;
unsigned long mask = BIT_MASK(bit);
p += BIT_WORD(bit);
raw_local_irq_save(flags);
*p &= ~mask;
raw_local_irq_restore(flags);
}
static inline void ____atomic_change_bit(unsigned int bit, volatile unsigned long *p)
{
unsigned long flags;
unsigned long mask = BIT_MASK(bit);
p += BIT_WORD(bit);
raw_local_irq_save(flags);
*p ^= mask;
raw_local_irq_restore(flags);
}
static inline int
____atomic_test_and_set_bit(unsigned int bit, volatile unsigned long *p)
{
unsigned long flags;
unsigned int res;
unsigned long mask = BIT_MASK(bit);
p += BIT_WORD(bit);
raw_local_irq_save(flags);
res = *p;
*p = res | mask;
raw_local_irq_restore(flags);
return (res & mask) != 0;
}
static inline int
____atomic_test_and_clear_bit(unsigned int bit, volatile unsigned long *p)
{
unsigned long flags;
unsigned int res;
unsigned long mask = BIT_MASK(bit);
p += BIT_WORD(bit);
raw_local_irq_save(flags);
res = *p;
*p = res & ~mask;
raw_local_irq_restore(flags);
return (res & mask) != 0;
}
static inline int
____atomic_test_and_change_bit(unsigned int bit, volatile unsigned long *p)
{
unsigned long flags;
unsigned int res;
unsigned long mask = BIT_MASK(bit);
p += BIT_WORD(bit);
raw_local_irq_save(flags);
res = *p;
*p = res ^ mask;
raw_local_irq_restore(flags);
return (res & mask) != 0;
}
#include <asm-generic/bitops/non-atomic.h>
/*
* A note about Endian-ness.
* -------------------------
*
* When the ARM is put into big endian mode via CR15, the processor
* merely swaps the order of bytes within words, thus:
*
* ------------ physical data bus bits -----------
* D31 ... D24 D23 ... D16 D15 ... D8 D7 ... D0
* little byte 3 byte 2 byte 1 byte 0
* big byte 0 byte 1 byte 2 byte 3
*
* This means that reading a 32-bit word at address 0 returns the same
* value irrespective of the endian mode bit.
*
* Peripheral devices should be connected with the data bus reversed in
* "Big Endian" mode. ARM Application Note 61 is applicable, and is
* available from http://www.arm.com/.
*
* The following assumes that the data bus connectivity for big endian
* mode has been followed.
*
* Note that bit 0 is defined to be 32-bit word bit 0, not byte 0 bit 0.
*/
/*
* Native endian assembly bitops. nr = 0 -> word 0 bit 0.
*/
extern void _set_bit(int nr, volatile unsigned long * p);
extern void _clear_bit(int nr, volatile unsigned long * p);
extern void _change_bit(int nr, volatile unsigned long * p);
extern int _test_and_set_bit(int nr, volatile unsigned long * p);
extern int _test_and_clear_bit(int nr, volatile unsigned long * p);
extern int _test_and_change_bit(int nr, volatile unsigned long * p);
/*
* Little endian assembly bitops. nr = 0 -> byte 0 bit 0.
*/
unsigned long _find_first_zero_bit_le(const unsigned long *p, unsigned long size);
unsigned long _find_next_zero_bit_le(const unsigned long *p,
unsigned long size, unsigned long offset);
unsigned long _find_first_bit_le(const unsigned long *p, unsigned long size);
unsigned long _find_next_bit_le(const unsigned long *p, unsigned long size, unsigned long offset);
/*
* Big endian assembly bitops. nr = 0 -> byte 3 bit 0.
*/
unsigned long _find_first_zero_bit_be(const unsigned long *p, unsigned long size);
unsigned long _find_next_zero_bit_be(const unsigned long *p,
unsigned long size, unsigned long offset);
unsigned long _find_first_bit_be(const unsigned long *p, unsigned long size);
unsigned long _find_next_bit_be(const unsigned long *p, unsigned long size, unsigned long offset);
#ifndef CONFIG_SMP
/*
* The __* form of bitops are non-atomic and may be reordered.
*/
#define ATOMIC_BITOP(name,nr,p) \
(__builtin_constant_p(nr) ? ____atomic_##name(nr, p) : _##name(nr,p))
#else
#define ATOMIC_BITOP(name,nr,p) _##name(nr,p)
#endif
/*
* Native endian atomic definitions.
*/
#define set_bit(nr,p) ATOMIC_BITOP(set_bit,nr,p)
#define clear_bit(nr,p) ATOMIC_BITOP(clear_bit,nr,p)
#define change_bit(nr,p) ATOMIC_BITOP(change_bit,nr,p)
#define test_and_set_bit(nr,p) ATOMIC_BITOP(test_and_set_bit,nr,p)
#define test_and_clear_bit(nr,p) ATOMIC_BITOP(test_and_clear_bit,nr,p)
#define test_and_change_bit(nr,p) ATOMIC_BITOP(test_and_change_bit,nr,p)
#ifndef __ARMEB__
/*
* These are the little endian, atomic definitions.
*/
#define find_first_zero_bit(p,sz) _find_first_zero_bit_le(p,sz)
#define find_next_zero_bit(p,sz,off) _find_next_zero_bit_le(p,sz,off)
#define find_first_bit(p,sz) _find_first_bit_le(p,sz)
#define find_next_bit(p,sz,off) _find_next_bit_le(p,sz,off)
#else
/*
* These are the big endian, atomic definitions.
*/
#define find_first_zero_bit(p,sz) _find_first_zero_bit_be(p,sz)
#define find_next_zero_bit(p,sz,off) _find_next_zero_bit_be(p,sz,off)
#define find_first_bit(p,sz) _find_first_bit_be(p,sz)
#define find_next_bit(p,sz,off) _find_next_bit_be(p,sz,off)
#endif
#if __LINUX_ARM_ARCH__ < 5
#include <asm-generic/bitops/__fls.h>
#include <asm-generic/bitops/__ffs.h>
#include <asm-generic/bitops/fls.h>
#include <asm-generic/bitops/ffs.h>
#else
/*
* On ARMv5 and above, the gcc built-ins may rely on the clz instruction
* and produce optimal inlined code in all cases. On ARMv7 it is even
* better by also using the rbit instruction.
*/
#include <asm-generic/bitops/builtin-__fls.h>
#include <asm-generic/bitops/builtin-__ffs.h>
#include <asm-generic/bitops/builtin-fls.h>
#include <asm-generic/bitops/builtin-ffs.h>
#endif
#include <asm-generic/bitops/ffz.h>
#include <asm-generic/bitops/fls64.h>
#include <asm-generic/bitops/sched.h>
#include <asm-generic/bitops/hweight.h>
#include <asm-generic/bitops/lock.h>
#ifdef __ARMEB__
static inline int find_first_zero_bit_le(const void *p, unsigned size)
{
return _find_first_zero_bit_le(p, size);
}
#define find_first_zero_bit_le find_first_zero_bit_le
static inline int find_next_zero_bit_le(const void *p, int size, int offset)
{
return _find_next_zero_bit_le(p, size, offset);
}
#define find_next_zero_bit_le find_next_zero_bit_le
static inline int find_next_bit_le(const void *p, int size, int offset)
{
return _find_next_bit_le(p, size, offset);
}
#define find_next_bit_le find_next_bit_le
#endif
#include <asm-generic/bitops/le.h>
/*
* Ext2 is defined to use little-endian byte ordering.
*/
#include <asm-generic/bitops/ext2-atomic-setbit.h>
#endif /* __KERNEL__ */
#endif /* _ARM_BITOPS_H */
Codebase Browser
linux