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yaml
---
r: 93676
b: refs/heads/master
c: 77b9bd9
h: refs/heads/master
v: v3
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Alexander van Heukelum authored and Ingo Molnar committed Apr 26, 2008
1 parent 7ef4a30 commit 589a985
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Showing 6 changed files with 99 additions and 1 deletion.
2 changes: 1 addition & 1 deletion [refs]
Original file line number Diff line number Diff line change
@@ -1,2 +1,2 @@
---
refs/heads/master: d57594c203b1e7b54373080a797f0cbfa4aade68
refs/heads/master: 77b9bd9c49442407804c37bcc82021a35277f83c
3 changes: 3 additions & 0 deletions trunk/arch/x86/Kconfig
Original file line number Diff line number Diff line change
Expand Up @@ -77,6 +77,9 @@ config GENERIC_BUG
def_bool y
depends on BUG

config GENERIC_FIND_FIRST_BIT
def_bool X86_32

config GENERIC_FIND_NEXT_BIT
def_bool y

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2 changes: 2 additions & 0 deletions trunk/include/asm-x86/bitops_32.h
Original file line number Diff line number Diff line change
Expand Up @@ -5,6 +5,7 @@
* Copyright 1992, Linus Torvalds.
*/

#ifndef CONFIG_GENERIC_FIND_FIRST_BIT
/**
* find_first_zero_bit - find the first zero bit in a memory region
* @addr: The address to start the search at
Expand Down Expand Up @@ -59,6 +60,7 @@ static inline unsigned find_first_bit(const unsigned long *addr, unsigned size)
}
return x;
}
#endif

#ifdef __KERNEL__

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34 changes: 34 additions & 0 deletions trunk/include/linux/bitops.h
Original file line number Diff line number Diff line change
Expand Up @@ -113,6 +113,40 @@ static inline unsigned fls_long(unsigned long l)
}

#ifdef __KERNEL__
#ifdef CONFIG_GENERIC_FIND_FIRST_BIT
extern unsigned long __find_first_bit(const unsigned long *addr,
unsigned long size);

/**
* find_first_bit - find the first set bit in a memory region
* @addr: The address to start the search at
* @size: The maximum size to search
*
* Returns the bit number of the first set bit.
*/
static __always_inline unsigned long
find_first_bit(const unsigned long *addr, unsigned long size)
{
return __find_first_bit(addr, size);
}

extern unsigned long __find_first_zero_bit(const unsigned long *addr,
unsigned long size);

/**
* find_first_zero_bit - find the first cleared bit in a memory region
* @addr: The address to start the search at
* @size: The maximum size to search
*
* Returns the bit number of the first cleared bit.
*/
static __always_inline unsigned long
find_first_zero_bit(const unsigned long *addr, unsigned long size)
{
return __find_first_zero_bit(addr, size);
}
#endif /* CONFIG_GENERIC_FIND_FIRST_BIT */

#ifdef CONFIG_GENERIC_FIND_NEXT_BIT
extern unsigned long __find_next_bit(const unsigned long *addr,
unsigned long size, unsigned long offset);
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1 change: 1 addition & 0 deletions trunk/lib/Makefile
Original file line number Diff line number Diff line change
Expand Up @@ -29,6 +29,7 @@ obj-$(CONFIG_DEBUG_LOCKING_API_SELFTESTS) += locking-selftest.o
obj-$(CONFIG_DEBUG_SPINLOCK) += spinlock_debug.o
lib-$(CONFIG_RWSEM_GENERIC_SPINLOCK) += rwsem-spinlock.o
lib-$(CONFIG_RWSEM_XCHGADD_ALGORITHM) += rwsem.o
lib-$(CONFIG_GENERIC_FIND_FIRST_BIT) += find_next_bit.o
lib-$(CONFIG_GENERIC_FIND_NEXT_BIT) += find_next_bit.o
obj-$(CONFIG_GENERIC_HWEIGHT) += hweight.o
obj-$(CONFIG_LOCK_KERNEL) += kernel_lock.o
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58 changes: 58 additions & 0 deletions trunk/lib/find_next_bit.c
Original file line number Diff line number Diff line change
Expand Up @@ -16,6 +16,7 @@

#define BITOP_WORD(nr) ((nr) / BITS_PER_LONG)

#ifdef CONFIG_GENERIC_FIND_NEXT_BIT
/*
* Find the next set bit in a memory region.
*/
Expand Down Expand Up @@ -102,6 +103,63 @@ unsigned long __find_next_zero_bit(const unsigned long *addr,
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

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