6d9b37a3a8
Convert explicit gcc asm-based memory barriers into smp_mb() calls. These change between barrier() and the ARMv6 data memory barrier instruction depending on whether ARMv6 SMP is enabled. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
417 lines
11 KiB
C
417 lines
11 KiB
C
/*
|
|
* 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__
|
|
|
|
#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;
|
|
|
|
local_irq_save(flags);
|
|
*p |= mask;
|
|
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;
|
|
|
|
local_irq_save(flags);
|
|
*p &= ~mask;
|
|
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;
|
|
|
|
local_irq_save(flags);
|
|
*p ^= mask;
|
|
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;
|
|
|
|
local_irq_save(flags);
|
|
res = *p;
|
|
*p = res | mask;
|
|
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;
|
|
|
|
local_irq_save(flags);
|
|
res = *p;
|
|
*p = res & ~mask;
|
|
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;
|
|
|
|
local_irq_save(flags);
|
|
res = *p;
|
|
*p = res ^ mask;
|
|
local_irq_restore(flags);
|
|
|
|
return res & mask;
|
|
}
|
|
|
|
/*
|
|
* Now the non-atomic variants. We let the compiler handle all
|
|
* optimisations for these. These are all _native_ endian.
|
|
*/
|
|
static inline void __set_bit(int nr, volatile unsigned long *p)
|
|
{
|
|
p[nr >> 5] |= (1UL << (nr & 31));
|
|
}
|
|
|
|
static inline void __clear_bit(int nr, volatile unsigned long *p)
|
|
{
|
|
p[nr >> 5] &= ~(1UL << (nr & 31));
|
|
}
|
|
|
|
static inline void __change_bit(int nr, volatile unsigned long *p)
|
|
{
|
|
p[nr >> 5] ^= (1UL << (nr & 31));
|
|
}
|
|
|
|
static inline int __test_and_set_bit(int nr, volatile unsigned long *p)
|
|
{
|
|
unsigned long oldval, mask = 1UL << (nr & 31);
|
|
|
|
p += nr >> 5;
|
|
|
|
oldval = *p;
|
|
*p = oldval | mask;
|
|
return oldval & mask;
|
|
}
|
|
|
|
static inline int __test_and_clear_bit(int nr, volatile unsigned long *p)
|
|
{
|
|
unsigned long oldval, mask = 1UL << (nr & 31);
|
|
|
|
p += nr >> 5;
|
|
|
|
oldval = *p;
|
|
*p = oldval & ~mask;
|
|
return oldval & mask;
|
|
}
|
|
|
|
static inline int __test_and_change_bit(int nr, volatile unsigned long *p)
|
|
{
|
|
unsigned long oldval, mask = 1UL << (nr & 31);
|
|
|
|
p += nr >> 5;
|
|
|
|
oldval = *p;
|
|
*p = oldval ^ mask;
|
|
return oldval & mask;
|
|
}
|
|
|
|
/*
|
|
* This routine doesn't need to be atomic.
|
|
*/
|
|
static inline int __test_bit(int nr, const volatile unsigned long * p)
|
|
{
|
|
return (p[nr >> 5] >> (nr & 31)) & 1UL;
|
|
}
|
|
|
|
/*
|
|
* 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);
|
|
|
|
/*
|
|
* 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))
|
|
|
|
#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 test_bit(nr,p) __test_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 test_bit(nr,p) __test_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
|
|
|
|
/*
|
|
* ffz = Find First Zero in word. Undefined if no zero exists,
|
|
* so code should check against ~0UL first..
|
|
*/
|
|
static inline unsigned long ffz(unsigned long word)
|
|
{
|
|
int k;
|
|
|
|
word = ~word;
|
|
k = 31;
|
|
if (word & 0x0000ffff) { k -= 16; word <<= 16; }
|
|
if (word & 0x00ff0000) { k -= 8; word <<= 8; }
|
|
if (word & 0x0f000000) { k -= 4; word <<= 4; }
|
|
if (word & 0x30000000) { k -= 2; word <<= 2; }
|
|
if (word & 0x40000000) { k -= 1; }
|
|
return k;
|
|
}
|
|
|
|
/*
|
|
* ffz = Find First Zero in word. Undefined if no zero exists,
|
|
* so code should check against ~0UL first..
|
|
*/
|
|
static inline unsigned long __ffs(unsigned long word)
|
|
{
|
|
int k;
|
|
|
|
k = 31;
|
|
if (word & 0x0000ffff) { k -= 16; word <<= 16; }
|
|
if (word & 0x00ff0000) { k -= 8; word <<= 8; }
|
|
if (word & 0x0f000000) { k -= 4; word <<= 4; }
|
|
if (word & 0x30000000) { k -= 2; word <<= 2; }
|
|
if (word & 0x40000000) { k -= 1; }
|
|
return k;
|
|
}
|
|
|
|
/*
|
|
* fls: find last bit set.
|
|
*/
|
|
|
|
#define fls(x) generic_fls(x)
|
|
|
|
/*
|
|
* ffs: find first bit set. This is defined the same way as
|
|
* the libc and compiler builtin ffs routines, therefore
|
|
* differs in spirit from the above ffz (man ffs).
|
|
*/
|
|
|
|
#define ffs(x) generic_ffs(x)
|
|
|
|
#else
|
|
|
|
/*
|
|
* On ARMv5 and above those functions can be implemented around
|
|
* the clz instruction for much better code efficiency.
|
|
*/
|
|
|
|
static __inline__ int generic_fls(int x);
|
|
#define fls(x) \
|
|
( __builtin_constant_p(x) ? generic_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
|
|
|
|
/*
|
|
* Find first bit set in a 168-bit bitmap, where the first
|
|
* 128 bits are unlikely to be set.
|
|
*/
|
|
static inline int sched_find_first_bit(const unsigned long *b)
|
|
{
|
|
unsigned long v;
|
|
unsigned int off;
|
|
|
|
for (off = 0; v = b[off], off < 4; off++) {
|
|
if (unlikely(v))
|
|
break;
|
|
}
|
|
return __ffs(v) + off * 32;
|
|
}
|
|
|
|
/*
|
|
* hweightN: returns the hamming weight (i.e. the number
|
|
* of bits set) of a N-bit word
|
|
*/
|
|
|
|
#define hweight32(x) generic_hweight32(x)
|
|
#define hweight16(x) generic_hweight16(x)
|
|
#define hweight8(x) generic_hweight8(x)
|
|
|
|
/*
|
|
* 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 */
|