mirror of
https://github.com/torvalds/linux.git
synced 2024-11-24 05:02:12 +00:00
fee4b19fb3
The mapsize optimizations which were moved from x86 to the generic
code in commit 64970b68d2 increased the
binary size on non x86 architectures.
Looking into the real effects of the "optimizations" it turned out
that they are not used in find_next_bit() and find_next_zero_bit().
The ones in find_first_bit() and find_first_zero_bit() are used in a
couple of places but none of them is a real hot path.
Remove the "optimizations" all together and call the library functions
unconditionally.
Boot-tested on x86 and compile tested on every cross compiler I have.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
276 lines
6.4 KiB
C
276 lines
6.4 KiB
C
/* find_next_bit.c: fallback find next bit implementation
|
|
*
|
|
* Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
|
|
* Written by David Howells (dhowells@redhat.com)
|
|
*
|
|
* 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.
|
|
*/
|
|
|
|
#include <linux/bitops.h>
|
|
#include <linux/module.h>
|
|
#include <asm/types.h>
|
|
#include <asm/byteorder.h>
|
|
|
|
#define BITOP_WORD(nr) ((nr) / BITS_PER_LONG)
|
|
|
|
#ifdef CONFIG_GENERIC_FIND_NEXT_BIT
|
|
/*
|
|
* Find the next set bit in a memory region.
|
|
*/
|
|
unsigned long find_next_bit(const unsigned long *addr, unsigned long size,
|
|
unsigned long offset)
|
|
{
|
|
const unsigned long *p = addr + BITOP_WORD(offset);
|
|
unsigned long result = offset & ~(BITS_PER_LONG-1);
|
|
unsigned long tmp;
|
|
|
|
if (offset >= size)
|
|
return size;
|
|
size -= result;
|
|
offset %= BITS_PER_LONG;
|
|
if (offset) {
|
|
tmp = *(p++);
|
|
tmp &= (~0UL << offset);
|
|
if (size < BITS_PER_LONG)
|
|
goto found_first;
|
|
if (tmp)
|
|
goto found_middle;
|
|
size -= BITS_PER_LONG;
|
|
result += BITS_PER_LONG;
|
|
}
|
|
while (size & ~(BITS_PER_LONG-1)) {
|
|
if ((tmp = *(p++)))
|
|
goto found_middle;
|
|
result += BITS_PER_LONG;
|
|
size -= BITS_PER_LONG;
|
|
}
|
|
if (!size)
|
|
return result;
|
|
tmp = *p;
|
|
|
|
found_first:
|
|
tmp &= (~0UL >> (BITS_PER_LONG - size));
|
|
if (tmp == 0UL) /* Are any bits set? */
|
|
return result + size; /* Nope. */
|
|
found_middle:
|
|
return result + __ffs(tmp);
|
|
}
|
|
EXPORT_SYMBOL(find_next_bit);
|
|
|
|
/*
|
|
* This implementation of find_{first,next}_zero_bit was stolen from
|
|
* Linus' asm-alpha/bitops.h.
|
|
*/
|
|
unsigned long find_next_zero_bit(const unsigned long *addr, unsigned long size,
|
|
unsigned long offset)
|
|
{
|
|
const unsigned long *p = addr + BITOP_WORD(offset);
|
|
unsigned long result = offset & ~(BITS_PER_LONG-1);
|
|
unsigned long tmp;
|
|
|
|
if (offset >= size)
|
|
return size;
|
|
size -= result;
|
|
offset %= BITS_PER_LONG;
|
|
if (offset) {
|
|
tmp = *(p++);
|
|
tmp |= ~0UL >> (BITS_PER_LONG - offset);
|
|
if (size < BITS_PER_LONG)
|
|
goto found_first;
|
|
if (~tmp)
|
|
goto found_middle;
|
|
size -= BITS_PER_LONG;
|
|
result += BITS_PER_LONG;
|
|
}
|
|
while (size & ~(BITS_PER_LONG-1)) {
|
|
if (~(tmp = *(p++)))
|
|
goto found_middle;
|
|
result += BITS_PER_LONG;
|
|
size -= BITS_PER_LONG;
|
|
}
|
|
if (!size)
|
|
return result;
|
|
tmp = *p;
|
|
|
|
found_first:
|
|
tmp |= ~0UL << size;
|
|
if (tmp == ~0UL) /* Are any bits zero? */
|
|
return result + size; /* Nope. */
|
|
found_middle:
|
|
return result + ffz(tmp);
|
|
}
|
|
EXPORT_SYMBOL(find_next_zero_bit);
|
|
#endif /* CONFIG_GENERIC_FIND_NEXT_BIT */
|
|
|
|
#ifdef CONFIG_GENERIC_FIND_FIRST_BIT
|
|
/*
|
|
* Find the first set bit in a memory region.
|
|
*/
|
|
unsigned long find_first_bit(const unsigned long *addr, unsigned long size)
|
|
{
|
|
const unsigned long *p = addr;
|
|
unsigned long result = 0;
|
|
unsigned long tmp;
|
|
|
|
while (size & ~(BITS_PER_LONG-1)) {
|
|
if ((tmp = *(p++)))
|
|
goto found;
|
|
result += BITS_PER_LONG;
|
|
size -= BITS_PER_LONG;
|
|
}
|
|
if (!size)
|
|
return result;
|
|
|
|
tmp = (*p) & (~0UL >> (BITS_PER_LONG - size));
|
|
if (tmp == 0UL) /* Are any bits set? */
|
|
return result + size; /* Nope. */
|
|
found:
|
|
return result + __ffs(tmp);
|
|
}
|
|
EXPORT_SYMBOL(find_first_bit);
|
|
|
|
/*
|
|
* Find the first cleared bit in a memory region.
|
|
*/
|
|
unsigned long find_first_zero_bit(const unsigned long *addr, unsigned long size)
|
|
{
|
|
const unsigned long *p = addr;
|
|
unsigned long result = 0;
|
|
unsigned long tmp;
|
|
|
|
while (size & ~(BITS_PER_LONG-1)) {
|
|
if (~(tmp = *(p++)))
|
|
goto found;
|
|
result += BITS_PER_LONG;
|
|
size -= BITS_PER_LONG;
|
|
}
|
|
if (!size)
|
|
return result;
|
|
|
|
tmp = (*p) | (~0UL << size);
|
|
if (tmp == ~0UL) /* Are any bits zero? */
|
|
return result + size; /* Nope. */
|
|
found:
|
|
return result + ffz(tmp);
|
|
}
|
|
EXPORT_SYMBOL(find_first_zero_bit);
|
|
#endif /* CONFIG_GENERIC_FIND_FIRST_BIT */
|
|
|
|
#ifdef __BIG_ENDIAN
|
|
|
|
/* include/linux/byteorder does not support "unsigned long" type */
|
|
static inline unsigned long ext2_swabp(const unsigned long * x)
|
|
{
|
|
#if BITS_PER_LONG == 64
|
|
return (unsigned long) __swab64p((u64 *) x);
|
|
#elif BITS_PER_LONG == 32
|
|
return (unsigned long) __swab32p((u32 *) x);
|
|
#else
|
|
#error BITS_PER_LONG not defined
|
|
#endif
|
|
}
|
|
|
|
/* include/linux/byteorder doesn't support "unsigned long" type */
|
|
static inline unsigned long ext2_swab(const unsigned long y)
|
|
{
|
|
#if BITS_PER_LONG == 64
|
|
return (unsigned long) __swab64((u64) y);
|
|
#elif BITS_PER_LONG == 32
|
|
return (unsigned long) __swab32((u32) y);
|
|
#else
|
|
#error BITS_PER_LONG not defined
|
|
#endif
|
|
}
|
|
|
|
unsigned long generic_find_next_zero_le_bit(const unsigned long *addr, unsigned
|
|
long size, unsigned long offset)
|
|
{
|
|
const unsigned long *p = addr + BITOP_WORD(offset);
|
|
unsigned long result = offset & ~(BITS_PER_LONG - 1);
|
|
unsigned long tmp;
|
|
|
|
if (offset >= size)
|
|
return size;
|
|
size -= result;
|
|
offset &= (BITS_PER_LONG - 1UL);
|
|
if (offset) {
|
|
tmp = ext2_swabp(p++);
|
|
tmp |= (~0UL >> (BITS_PER_LONG - offset));
|
|
if (size < BITS_PER_LONG)
|
|
goto found_first;
|
|
if (~tmp)
|
|
goto found_middle;
|
|
size -= BITS_PER_LONG;
|
|
result += BITS_PER_LONG;
|
|
}
|
|
|
|
while (size & ~(BITS_PER_LONG - 1)) {
|
|
if (~(tmp = *(p++)))
|
|
goto found_middle_swap;
|
|
result += BITS_PER_LONG;
|
|
size -= BITS_PER_LONG;
|
|
}
|
|
if (!size)
|
|
return result;
|
|
tmp = ext2_swabp(p);
|
|
found_first:
|
|
tmp |= ~0UL << size;
|
|
if (tmp == ~0UL) /* Are any bits zero? */
|
|
return result + size; /* Nope. Skip ffz */
|
|
found_middle:
|
|
return result + ffz(tmp);
|
|
|
|
found_middle_swap:
|
|
return result + ffz(ext2_swab(tmp));
|
|
}
|
|
|
|
EXPORT_SYMBOL(generic_find_next_zero_le_bit);
|
|
|
|
unsigned long generic_find_next_le_bit(const unsigned long *addr, unsigned
|
|
long size, unsigned long offset)
|
|
{
|
|
const unsigned long *p = addr + BITOP_WORD(offset);
|
|
unsigned long result = offset & ~(BITS_PER_LONG - 1);
|
|
unsigned long tmp;
|
|
|
|
if (offset >= size)
|
|
return size;
|
|
size -= result;
|
|
offset &= (BITS_PER_LONG - 1UL);
|
|
if (offset) {
|
|
tmp = ext2_swabp(p++);
|
|
tmp &= (~0UL << offset);
|
|
if (size < BITS_PER_LONG)
|
|
goto found_first;
|
|
if (tmp)
|
|
goto found_middle;
|
|
size -= BITS_PER_LONG;
|
|
result += BITS_PER_LONG;
|
|
}
|
|
|
|
while (size & ~(BITS_PER_LONG - 1)) {
|
|
tmp = *(p++);
|
|
if (tmp)
|
|
goto found_middle_swap;
|
|
result += BITS_PER_LONG;
|
|
size -= BITS_PER_LONG;
|
|
}
|
|
if (!size)
|
|
return result;
|
|
tmp = ext2_swabp(p);
|
|
found_first:
|
|
tmp &= (~0UL >> (BITS_PER_LONG - size));
|
|
if (tmp == 0UL) /* Are any bits set? */
|
|
return result + size; /* Nope. */
|
|
found_middle:
|
|
return result + __ffs(tmp);
|
|
|
|
found_middle_swap:
|
|
return result + __ffs(ext2_swab(tmp));
|
|
}
|
|
EXPORT_SYMBOL(generic_find_next_le_bit);
|
|
#endif /* __BIG_ENDIAN */
|