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linux/include/asm-arm/bitops.h
Jiri Slaby 0624517d80 forbid asm/bitops.h direct inclusion 
forbid asm/bitops.h direct inclusion

Because of compile errors that may occur after bit changes if asm/bitops.h is
included directly without e.g.  linux/kernel.h which includes linux/bitops.h,
forbid direct inclusion of asm/bitops.h.  Thanks to Adrian Bunk.

Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Cc: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-19 11:53:41 -07:00

332 lines
9.4 KiB
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/*
* 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 <asm/system.h>
#define smp_mb__before_clear_bit() mb()
#define smp_mb__after_clear_bit() mb()
/*
* 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 = 1UL << (bit & 31);
p += bit >> 5;
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 = 1UL << (bit & 31);
p += bit >> 5;
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 = 1UL << (bit & 31);
p += bit >> 5;
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 = 1UL << (bit & 31);
p += bit >> 5;
raw_local_irq_save(flags);
res = *p;
*p = res | mask;
raw_local_irq_restore(flags);
return res & mask;
}
static inline int
____atomic_test_and_clear_bit(unsigned int bit, volatile unsigned long *p)
{
unsigned long flags;
unsigned int res;
unsigned long mask = 1UL << (bit & 31);
p += bit >> 5;
raw_local_irq_save(flags);
res = *p;
*p = res & ~mask;
raw_local_irq_restore(flags);
return res & mask;
}
static inline int
____atomic_test_and_change_bit(unsigned int bit, volatile unsigned long *p)
{
unsigned long flags;
unsigned int res;
unsigned long mask = 1UL << (bit & 31);
p += bit >> 5;
raw_local_irq_save(flags);
res = *p;
*p = res ^ mask;
raw_local_irq_restore(flags);
return res & mask;
}
#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.
*/
/*
* Little endian assembly bitops. nr = 0 -> byte 0 bit 0.
*/
extern void _set_bit_le(int nr, volatile unsigned long * p);
extern void _clear_bit_le(int nr, volatile unsigned long * p);
extern void _change_bit_le(int nr, volatile unsigned long * p);
extern int _test_and_set_bit_le(int nr, volatile unsigned long * p);
extern int _test_and_clear_bit_le(int nr, volatile unsigned long * p);
extern int _test_and_change_bit_le(int nr, volatile unsigned long * p);
extern int _find_first_zero_bit_le(const void * p, unsigned size);
extern int _find_next_zero_bit_le(const void * p, int size, int offset);
extern int _find_first_bit_le(const unsigned long *p, unsigned size);
extern int _find_next_bit_le(const unsigned long *p, int size, int offset);
/*
* Big endian assembly bitops. nr = 0 -> byte 3 bit 0.
*/
extern void _set_bit_be(int nr, volatile unsigned long * p);
extern void _clear_bit_be(int nr, volatile unsigned long * p);
extern void _change_bit_be(int nr, volatile unsigned long * p);
extern int _test_and_set_bit_be(int nr, volatile unsigned long * p);
extern int _test_and_clear_bit_be(int nr, volatile unsigned long * p);
extern int _test_and_change_bit_be(int nr, volatile unsigned long * p);
extern int _find_first_zero_bit_be(const void * p, unsigned size);
extern int _find_next_zero_bit_be(const void * p, int size, int offset);
extern int _find_first_bit_be(const unsigned long *p, unsigned size);
extern int _find_next_bit_be(const unsigned long *p, int size, int offset);
#ifndef CONFIG_SMP
/*
* The __* form of bitops are non-atomic and may be reordered.
*/
#define ATOMIC_BITOP_LE(name,nr,p) \
(__builtin_constant_p(nr) ? \
____atomic_##name(nr, p) : \
_##name##_le(nr,p))
#define ATOMIC_BITOP_BE(name,nr,p) \
(__builtin_constant_p(nr) ? \
____atomic_##name(nr, p) : \
_##name##_be(nr,p))
#else
#define ATOMIC_BITOP_LE(name,nr,p) _##name##_le(nr,p)
#define ATOMIC_BITOP_BE(name,nr,p) _##name##_be(nr,p)
#endif
#define NONATOMIC_BITOP(name,nr,p) \
(____nonatomic_##name(nr, p))
#ifndef __ARMEB__
/*
* These are the little endian, atomic definitions.
*/
#define set_bit(nr,p) ATOMIC_BITOP_LE(set_bit,nr,p)
#define clear_bit(nr,p) ATOMIC_BITOP_LE(clear_bit,nr,p)
#define change_bit(nr,p) ATOMIC_BITOP_LE(change_bit,nr,p)
#define test_and_set_bit(nr,p) ATOMIC_BITOP_LE(test_and_set_bit,nr,p)
#define test_and_clear_bit(nr,p) ATOMIC_BITOP_LE(test_and_clear_bit,nr,p)
#define test_and_change_bit(nr,p) ATOMIC_BITOP_LE(test_and_change_bit,nr,p)
#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)
#define WORD_BITOFF_TO_LE(x) ((x))
#else
/*
* These are the big endian, atomic definitions.
*/
#define set_bit(nr,p) ATOMIC_BITOP_BE(set_bit,nr,p)
#define clear_bit(nr,p) ATOMIC_BITOP_BE(clear_bit,nr,p)
#define change_bit(nr,p) ATOMIC_BITOP_BE(change_bit,nr,p)
#define test_and_set_bit(nr,p) ATOMIC_BITOP_BE(test_and_set_bit,nr,p)
#define test_and_clear_bit(nr,p) ATOMIC_BITOP_BE(test_and_clear_bit,nr,p)
#define test_and_change_bit(nr,p) ATOMIC_BITOP_BE(test_and_change_bit,nr,p)
#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)
#define WORD_BITOFF_TO_LE(x) ((x) ^ 0x18)
#endif
#if __LINUX_ARM_ARCH__ < 5
#include <asm-generic/bitops/ffz.h>
#include <asm-generic/bitops/__ffs.h>
#include <asm-generic/bitops/fls.h>
#include <asm-generic/bitops/ffs.h>
#else
static inline int constant_fls(int x)
{
int r = 32;
if (!x)
return 0;
if (!(x & 0xffff0000u)) {
x <<= 16;
r -= 16;
}
if (!(x & 0xff000000u)) {
x <<= 8;
r -= 8;
}
if (!(x & 0xf0000000u)) {
x <<= 4;
r -= 4;
}
if (!(x & 0xc0000000u)) {
x <<= 2;
r -= 2;
}
if (!(x & 0x80000000u)) {
x <<= 1;
r -= 1;
}
return r;
}
/*
* On ARMv5 and above those functions can be implemented around
* the clz instruction for much better code efficiency.
*/
#define fls(x) \
( __builtin_constant_p(x) ? constant_fls(x) : \
({ int __r; asm("clz\t%0, %1" : "=r"(__r) : "r"(x) : "cc"); 32-__r; }) )
#define ffs(x) ({ unsigned long __t = (x); fls(__t & -__t); })
#define __ffs(x) (ffs(x) - 1)
#define ffz(x) __ffs( ~(x) )
#endif
#include <asm-generic/bitops/fls64.h>
#include <asm-generic/bitops/sched.h>
#include <asm-generic/bitops/hweight.h>
#include <asm-generic/bitops/lock.h>
/*
* Ext2 is defined to use little-endian byte ordering.
* These do not need to be atomic.
*/
#define ext2_set_bit(nr,p) \
__test_and_set_bit(WORD_BITOFF_TO_LE(nr), (unsigned long *)(p))
#define ext2_set_bit_atomic(lock,nr,p) \
test_and_set_bit(WORD_BITOFF_TO_LE(nr), (unsigned long *)(p))
#define ext2_clear_bit(nr,p) \
__test_and_clear_bit(WORD_BITOFF_TO_LE(nr), (unsigned long *)(p))
#define ext2_clear_bit_atomic(lock,nr,p) \
test_and_clear_bit(WORD_BITOFF_TO_LE(nr), (unsigned long *)(p))
#define ext2_test_bit(nr,p) \
test_bit(WORD_BITOFF_TO_LE(nr), (unsigned long *)(p))
#define ext2_find_first_zero_bit(p,sz) \
_find_first_zero_bit_le(p,sz)
#define ext2_find_next_zero_bit(p,sz,off) \
_find_next_zero_bit_le(p,sz,off)
/*
* Minix is defined to use little-endian byte ordering.
* These do not need to be atomic.
*/
#define minix_set_bit(nr,p) \
__set_bit(WORD_BITOFF_TO_LE(nr), (unsigned long *)(p))
#define minix_test_bit(nr,p) \
test_bit(WORD_BITOFF_TO_LE(nr), (unsigned long *)(p))
#define minix_test_and_set_bit(nr,p) \
__test_and_set_bit(WORD_BITOFF_TO_LE(nr), (unsigned long *)(p))
#define minix_test_and_clear_bit(nr,p) \
__test_and_clear_bit(WORD_BITOFF_TO_LE(nr), (unsigned long *)(p))
#define minix_find_first_zero_bit(p,sz) \
_find_first_zero_bit_le(p,sz)
#endif /* __KERNEL__ */
#endif /* _ARM_BITOPS_H */
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