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Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/x86/linux-2.6-generic-bitops-v3

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* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/x86/linux-2.6-generic-bitops-v3:
  x86, bitops: select the generic bitmap search functions
  x86: include/asm-x86/pgalloc.h/bitops.h: checkpatch cleanups - formatting only
  x86: finalize bitops unification
  x86, UML: remove x86-specific implementations of find_first_bit
  x86: optimize find_first_bit for small bitmaps
  x86: switch 64-bit to generic find_first_bit
  x86: generic versions of find_first_(zero_)bit, convert i386
  bitops: use __fls for fls64 on 64-bit archs
  generic: implement __fls on all 64-bit archs
  generic: introduce a generic __fls implementation
  x86: merge the simple bitops and move them to bitops.h
  x86, generic: optimize find_next_(zero_)bit for small constant-size bitmaps
  x86, uml: fix uml with generic find_next_bit for x86
  x86: change x86 to use generic find_next_bit
  uml: Kconfig cleanup
  uml: fix build error
This commit is contained in:
Linus Torvalds
2008-04-26 13:46:11 -07:00
parent a52b0d25a7 19870def58
commit 9b79ed952b
26 changed files with 467 additions and 603 deletions
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140
include/linux/bitops.h
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@@ -112,4 +112,144 @@ static inline unsigned fls_long(unsigned long l)
return fls64(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)
{
/* Avoid a function call if the bitmap size is a constant */
/* and not bigger than BITS_PER_LONG. */
/* insert a sentinel so that __ffs returns size if there */
/* are no set bits in the bitmap */
if (__builtin_constant_p(size) && (size < BITS_PER_LONG))
return __ffs((*addr) | (1ul << size));
/* the result of __ffs(0) is undefined, so it needs to be */
/* handled separately */
if (__builtin_constant_p(size) && (size == BITS_PER_LONG))
return ((*addr) == 0) ? BITS_PER_LONG : __ffs(*addr);
/* size is not constant or too big */
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)
{
/* Avoid a function call if the bitmap size is a constant */
/* and not bigger than BITS_PER_LONG. */
/* insert a sentinel so that __ffs returns size if there */
/* are no set bits in the bitmap */
if (__builtin_constant_p(size) && (size < BITS_PER_LONG)) {
return __ffs(~(*addr) | (1ul << size));
}
/* the result of __ffs(0) is undefined, so it needs to be */
/* handled separately */
if (__builtin_constant_p(size) && (size == BITS_PER_LONG))
return (~(*addr) == 0) ? BITS_PER_LONG : __ffs(~(*addr));
/* size is not constant or too big */
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);
/**
* find_next_bit - find the next set bit in a memory region
* @addr: The address to base the search on
* @offset: The bitnumber to start searching at
* @size: The bitmap size in bits
*/
static __always_inline unsigned long
find_next_bit(const unsigned long *addr, unsigned long size,
unsigned long offset)
{
unsigned long value;
/* Avoid a function call if the bitmap size is a constant */
/* and not bigger than BITS_PER_LONG. */
/* insert a sentinel so that __ffs returns size if there */
/* are no set bits in the bitmap */
if (__builtin_constant_p(size) && (size < BITS_PER_LONG)) {
value = (*addr) & ((~0ul) << offset);
value |= (1ul << size);
return __ffs(value);
}
/* the result of __ffs(0) is undefined, so it needs to be */
/* handled separately */
if (__builtin_constant_p(size) && (size == BITS_PER_LONG)) {
value = (*addr) & ((~0ul) << offset);
return (value == 0) ? BITS_PER_LONG : __ffs(value);
}
/* size is not constant or too big */
return __find_next_bit(addr, size, offset);
}
extern unsigned long __find_next_zero_bit(const unsigned long *addr,
unsigned long size, unsigned long offset);
/**
* find_next_zero_bit - find the next cleared bit in a memory region
* @addr: The address to base the search on
* @offset: The bitnumber to start searching at
* @size: The bitmap size in bits
*/
static __always_inline unsigned long
find_next_zero_bit(const unsigned long *addr, unsigned long size,
unsigned long offset)
{
unsigned long value;
/* Avoid a function call if the bitmap size is a constant */
/* and not bigger than BITS_PER_LONG. */
/* insert a sentinel so that __ffs returns size if there */
/* are no set bits in the bitmap */
if (__builtin_constant_p(size) && (size < BITS_PER_LONG)) {
value = (~(*addr)) & ((~0ul) << offset);
value |= (1ul << size);
return __ffs(value);
}
/* the result of __ffs(0) is undefined, so it needs to be */
/* handled separately */
if (__builtin_constant_p(size) && (size == BITS_PER_LONG)) {
value = (~(*addr)) & ((~0ul) << offset);
return (value == 0) ? BITS_PER_LONG : __ffs(value);
}
/* size is not constant or too big */
return __find_next_zero_bit(addr, size, offset);
}
#endif /* CONFIG_GENERIC_FIND_NEXT_BIT */
#endif /* __KERNEL__ */
#endif