mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-23 09:19:51 +00:00
![Rasmus Villemoes](/assets/img/avatar_default.png)
It's not clear what's so horrible about emitting a function call to handle a run-time sized bitmap. Moreover, gcc also emits a function call for a compile-time-constant-but-huge nbits, so the comment isn't even accurate. Link: http://lkml.kernel.org/r/20180818131623.8755-6-linux@rasmusvillemoes.dk Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Cc: Yury Norov <ynorov@caviumnetworks.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Sudeep Holla <sudeep.holla@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
470 lines
18 KiB
C
470 lines
18 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
|
|
#ifndef __LINUX_BITMAP_H
|
|
#define __LINUX_BITMAP_H
|
|
|
|
#ifndef __ASSEMBLY__
|
|
|
|
#include <linux/types.h>
|
|
#include <linux/bitops.h>
|
|
#include <linux/string.h>
|
|
#include <linux/kernel.h>
|
|
|
|
/*
|
|
* bitmaps provide bit arrays that consume one or more unsigned
|
|
* longs. The bitmap interface and available operations are listed
|
|
* here, in bitmap.h
|
|
*
|
|
* Function implementations generic to all architectures are in
|
|
* lib/bitmap.c. Functions implementations that are architecture
|
|
* specific are in various include/asm-<arch>/bitops.h headers
|
|
* and other arch/<arch> specific files.
|
|
*
|
|
* See lib/bitmap.c for more details.
|
|
*/
|
|
|
|
/**
|
|
* DOC: bitmap overview
|
|
*
|
|
* The available bitmap operations and their rough meaning in the
|
|
* case that the bitmap is a single unsigned long are thus:
|
|
*
|
|
* The generated code is more efficient when nbits is known at
|
|
* compile-time and at most BITS_PER_LONG.
|
|
*
|
|
* ::
|
|
*
|
|
* bitmap_zero(dst, nbits) *dst = 0UL
|
|
* bitmap_fill(dst, nbits) *dst = ~0UL
|
|
* bitmap_copy(dst, src, nbits) *dst = *src
|
|
* bitmap_and(dst, src1, src2, nbits) *dst = *src1 & *src2
|
|
* bitmap_or(dst, src1, src2, nbits) *dst = *src1 | *src2
|
|
* bitmap_xor(dst, src1, src2, nbits) *dst = *src1 ^ *src2
|
|
* bitmap_andnot(dst, src1, src2, nbits) *dst = *src1 & ~(*src2)
|
|
* bitmap_complement(dst, src, nbits) *dst = ~(*src)
|
|
* bitmap_equal(src1, src2, nbits) Are *src1 and *src2 equal?
|
|
* bitmap_intersects(src1, src2, nbits) Do *src1 and *src2 overlap?
|
|
* bitmap_subset(src1, src2, nbits) Is *src1 a subset of *src2?
|
|
* bitmap_empty(src, nbits) Are all bits zero in *src?
|
|
* bitmap_full(src, nbits) Are all bits set in *src?
|
|
* bitmap_weight(src, nbits) Hamming Weight: number set bits
|
|
* bitmap_set(dst, pos, nbits) Set specified bit area
|
|
* bitmap_clear(dst, pos, nbits) Clear specified bit area
|
|
* bitmap_find_next_zero_area(buf, len, pos, n, mask) Find bit free area
|
|
* bitmap_find_next_zero_area_off(buf, len, pos, n, mask) as above
|
|
* bitmap_shift_right(dst, src, n, nbits) *dst = *src >> n
|
|
* bitmap_shift_left(dst, src, n, nbits) *dst = *src << n
|
|
* bitmap_remap(dst, src, old, new, nbits) *dst = map(old, new)(src)
|
|
* bitmap_bitremap(oldbit, old, new, nbits) newbit = map(old, new)(oldbit)
|
|
* bitmap_onto(dst, orig, relmap, nbits) *dst = orig relative to relmap
|
|
* bitmap_fold(dst, orig, sz, nbits) dst bits = orig bits mod sz
|
|
* bitmap_parse(buf, buflen, dst, nbits) Parse bitmap dst from kernel buf
|
|
* bitmap_parse_user(ubuf, ulen, dst, nbits) Parse bitmap dst from user buf
|
|
* bitmap_parselist(buf, dst, nbits) Parse bitmap dst from kernel buf
|
|
* bitmap_parselist_user(buf, dst, nbits) Parse bitmap dst from user buf
|
|
* bitmap_find_free_region(bitmap, bits, order) Find and allocate bit region
|
|
* bitmap_release_region(bitmap, pos, order) Free specified bit region
|
|
* bitmap_allocate_region(bitmap, pos, order) Allocate specified bit region
|
|
* bitmap_from_arr32(dst, buf, nbits) Copy nbits from u32[] buf to dst
|
|
* bitmap_to_arr32(buf, src, nbits) Copy nbits from buf to u32[] dst
|
|
*
|
|
* Note, bitmap_zero() and bitmap_fill() operate over the region of
|
|
* unsigned longs, that is, bits behind bitmap till the unsigned long
|
|
* boundary will be zeroed or filled as well. Consider to use
|
|
* bitmap_clear() or bitmap_set() to make explicit zeroing or filling
|
|
* respectively.
|
|
*/
|
|
|
|
/**
|
|
* DOC: bitmap bitops
|
|
*
|
|
* Also the following operations in asm/bitops.h apply to bitmaps.::
|
|
*
|
|
* set_bit(bit, addr) *addr |= bit
|
|
* clear_bit(bit, addr) *addr &= ~bit
|
|
* change_bit(bit, addr) *addr ^= bit
|
|
* test_bit(bit, addr) Is bit set in *addr?
|
|
* test_and_set_bit(bit, addr) Set bit and return old value
|
|
* test_and_clear_bit(bit, addr) Clear bit and return old value
|
|
* test_and_change_bit(bit, addr) Change bit and return old value
|
|
* find_first_zero_bit(addr, nbits) Position first zero bit in *addr
|
|
* find_first_bit(addr, nbits) Position first set bit in *addr
|
|
* find_next_zero_bit(addr, nbits, bit)
|
|
* Position next zero bit in *addr >= bit
|
|
* find_next_bit(addr, nbits, bit) Position next set bit in *addr >= bit
|
|
* find_next_and_bit(addr1, addr2, nbits, bit)
|
|
* Same as find_next_bit, but in
|
|
* (*addr1 & *addr2)
|
|
*
|
|
*/
|
|
|
|
/**
|
|
* DOC: declare bitmap
|
|
* The DECLARE_BITMAP(name,bits) macro, in linux/types.h, can be used
|
|
* to declare an array named 'name' of just enough unsigned longs to
|
|
* contain all bit positions from 0 to 'bits' - 1.
|
|
*/
|
|
|
|
/*
|
|
* Allocation and deallocation of bitmap.
|
|
* Provided in lib/bitmap.c to avoid circular dependency.
|
|
*/
|
|
extern unsigned long *bitmap_alloc(unsigned int nbits, gfp_t flags);
|
|
extern unsigned long *bitmap_zalloc(unsigned int nbits, gfp_t flags);
|
|
extern void bitmap_free(const unsigned long *bitmap);
|
|
|
|
/*
|
|
* lib/bitmap.c provides these functions:
|
|
*/
|
|
|
|
extern int __bitmap_empty(const unsigned long *bitmap, unsigned int nbits);
|
|
extern int __bitmap_full(const unsigned long *bitmap, unsigned int nbits);
|
|
extern int __bitmap_equal(const unsigned long *bitmap1,
|
|
const unsigned long *bitmap2, unsigned int nbits);
|
|
extern void __bitmap_complement(unsigned long *dst, const unsigned long *src,
|
|
unsigned int nbits);
|
|
extern void __bitmap_shift_right(unsigned long *dst, const unsigned long *src,
|
|
unsigned int shift, unsigned int nbits);
|
|
extern void __bitmap_shift_left(unsigned long *dst, const unsigned long *src,
|
|
unsigned int shift, unsigned int nbits);
|
|
extern int __bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
|
|
const unsigned long *bitmap2, unsigned int nbits);
|
|
extern void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1,
|
|
const unsigned long *bitmap2, unsigned int nbits);
|
|
extern void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1,
|
|
const unsigned long *bitmap2, unsigned int nbits);
|
|
extern int __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,
|
|
const unsigned long *bitmap2, unsigned int nbits);
|
|
extern int __bitmap_intersects(const unsigned long *bitmap1,
|
|
const unsigned long *bitmap2, unsigned int nbits);
|
|
extern int __bitmap_subset(const unsigned long *bitmap1,
|
|
const unsigned long *bitmap2, unsigned int nbits);
|
|
extern int __bitmap_weight(const unsigned long *bitmap, unsigned int nbits);
|
|
extern void __bitmap_set(unsigned long *map, unsigned int start, int len);
|
|
extern void __bitmap_clear(unsigned long *map, unsigned int start, int len);
|
|
|
|
extern unsigned long bitmap_find_next_zero_area_off(unsigned long *map,
|
|
unsigned long size,
|
|
unsigned long start,
|
|
unsigned int nr,
|
|
unsigned long align_mask,
|
|
unsigned long align_offset);
|
|
|
|
/**
|
|
* bitmap_find_next_zero_area - find a contiguous aligned zero area
|
|
* @map: The address to base the search on
|
|
* @size: The bitmap size in bits
|
|
* @start: The bitnumber to start searching at
|
|
* @nr: The number of zeroed bits we're looking for
|
|
* @align_mask: Alignment mask for zero area
|
|
*
|
|
* The @align_mask should be one less than a power of 2; the effect is that
|
|
* the bit offset of all zero areas this function finds is multiples of that
|
|
* power of 2. A @align_mask of 0 means no alignment is required.
|
|
*/
|
|
static inline unsigned long
|
|
bitmap_find_next_zero_area(unsigned long *map,
|
|
unsigned long size,
|
|
unsigned long start,
|
|
unsigned int nr,
|
|
unsigned long align_mask)
|
|
{
|
|
return bitmap_find_next_zero_area_off(map, size, start, nr,
|
|
align_mask, 0);
|
|
}
|
|
|
|
extern int __bitmap_parse(const char *buf, unsigned int buflen, int is_user,
|
|
unsigned long *dst, int nbits);
|
|
extern int bitmap_parse_user(const char __user *ubuf, unsigned int ulen,
|
|
unsigned long *dst, int nbits);
|
|
extern int bitmap_parselist(const char *buf, unsigned long *maskp,
|
|
int nmaskbits);
|
|
extern int bitmap_parselist_user(const char __user *ubuf, unsigned int ulen,
|
|
unsigned long *dst, int nbits);
|
|
extern void bitmap_remap(unsigned long *dst, const unsigned long *src,
|
|
const unsigned long *old, const unsigned long *new, unsigned int nbits);
|
|
extern int bitmap_bitremap(int oldbit,
|
|
const unsigned long *old, const unsigned long *new, int bits);
|
|
extern void bitmap_onto(unsigned long *dst, const unsigned long *orig,
|
|
const unsigned long *relmap, unsigned int bits);
|
|
extern void bitmap_fold(unsigned long *dst, const unsigned long *orig,
|
|
unsigned int sz, unsigned int nbits);
|
|
extern int bitmap_find_free_region(unsigned long *bitmap, unsigned int bits, int order);
|
|
extern void bitmap_release_region(unsigned long *bitmap, unsigned int pos, int order);
|
|
extern int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order);
|
|
|
|
#ifdef __BIG_ENDIAN
|
|
extern void bitmap_copy_le(unsigned long *dst, const unsigned long *src, unsigned int nbits);
|
|
#else
|
|
#define bitmap_copy_le bitmap_copy
|
|
#endif
|
|
extern unsigned int bitmap_ord_to_pos(const unsigned long *bitmap, unsigned int ord, unsigned int nbits);
|
|
extern int bitmap_print_to_pagebuf(bool list, char *buf,
|
|
const unsigned long *maskp, int nmaskbits);
|
|
|
|
#define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) & (BITS_PER_LONG - 1)))
|
|
#define BITMAP_LAST_WORD_MASK(nbits) (~0UL >> (-(nbits) & (BITS_PER_LONG - 1)))
|
|
|
|
/*
|
|
* The static inlines below do not handle constant nbits==0 correctly,
|
|
* so make such users (should any ever turn up) call the out-of-line
|
|
* versions.
|
|
*/
|
|
#define small_const_nbits(nbits) \
|
|
(__builtin_constant_p(nbits) && (nbits) <= BITS_PER_LONG && (nbits) > 0)
|
|
|
|
static inline void bitmap_zero(unsigned long *dst, unsigned int nbits)
|
|
{
|
|
unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
|
|
memset(dst, 0, len);
|
|
}
|
|
|
|
static inline void bitmap_fill(unsigned long *dst, unsigned int nbits)
|
|
{
|
|
unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
|
|
memset(dst, 0xff, len);
|
|
}
|
|
|
|
static inline void bitmap_copy(unsigned long *dst, const unsigned long *src,
|
|
unsigned int nbits)
|
|
{
|
|
unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
|
|
memcpy(dst, src, len);
|
|
}
|
|
|
|
/*
|
|
* Copy bitmap and clear tail bits in last word.
|
|
*/
|
|
static inline void bitmap_copy_clear_tail(unsigned long *dst,
|
|
const unsigned long *src, unsigned int nbits)
|
|
{
|
|
bitmap_copy(dst, src, nbits);
|
|
if (nbits % BITS_PER_LONG)
|
|
dst[nbits / BITS_PER_LONG] &= BITMAP_LAST_WORD_MASK(nbits);
|
|
}
|
|
|
|
/*
|
|
* On 32-bit systems bitmaps are represented as u32 arrays internally, and
|
|
* therefore conversion is not needed when copying data from/to arrays of u32.
|
|
*/
|
|
#if BITS_PER_LONG == 64
|
|
extern void bitmap_from_arr32(unsigned long *bitmap, const u32 *buf,
|
|
unsigned int nbits);
|
|
extern void bitmap_to_arr32(u32 *buf, const unsigned long *bitmap,
|
|
unsigned int nbits);
|
|
#else
|
|
#define bitmap_from_arr32(bitmap, buf, nbits) \
|
|
bitmap_copy_clear_tail((unsigned long *) (bitmap), \
|
|
(const unsigned long *) (buf), (nbits))
|
|
#define bitmap_to_arr32(buf, bitmap, nbits) \
|
|
bitmap_copy_clear_tail((unsigned long *) (buf), \
|
|
(const unsigned long *) (bitmap), (nbits))
|
|
#endif
|
|
|
|
static inline int bitmap_and(unsigned long *dst, const unsigned long *src1,
|
|
const unsigned long *src2, unsigned int nbits)
|
|
{
|
|
if (small_const_nbits(nbits))
|
|
return (*dst = *src1 & *src2 & BITMAP_LAST_WORD_MASK(nbits)) != 0;
|
|
return __bitmap_and(dst, src1, src2, nbits);
|
|
}
|
|
|
|
static inline void bitmap_or(unsigned long *dst, const unsigned long *src1,
|
|
const unsigned long *src2, unsigned int nbits)
|
|
{
|
|
if (small_const_nbits(nbits))
|
|
*dst = *src1 | *src2;
|
|
else
|
|
__bitmap_or(dst, src1, src2, nbits);
|
|
}
|
|
|
|
static inline void bitmap_xor(unsigned long *dst, const unsigned long *src1,
|
|
const unsigned long *src2, unsigned int nbits)
|
|
{
|
|
if (small_const_nbits(nbits))
|
|
*dst = *src1 ^ *src2;
|
|
else
|
|
__bitmap_xor(dst, src1, src2, nbits);
|
|
}
|
|
|
|
static inline int bitmap_andnot(unsigned long *dst, const unsigned long *src1,
|
|
const unsigned long *src2, unsigned int nbits)
|
|
{
|
|
if (small_const_nbits(nbits))
|
|
return (*dst = *src1 & ~(*src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
|
|
return __bitmap_andnot(dst, src1, src2, nbits);
|
|
}
|
|
|
|
static inline void bitmap_complement(unsigned long *dst, const unsigned long *src,
|
|
unsigned int nbits)
|
|
{
|
|
if (small_const_nbits(nbits))
|
|
*dst = ~(*src);
|
|
else
|
|
__bitmap_complement(dst, src, nbits);
|
|
}
|
|
|
|
#ifdef __LITTLE_ENDIAN
|
|
#define BITMAP_MEM_ALIGNMENT 8
|
|
#else
|
|
#define BITMAP_MEM_ALIGNMENT (8 * sizeof(unsigned long))
|
|
#endif
|
|
#define BITMAP_MEM_MASK (BITMAP_MEM_ALIGNMENT - 1)
|
|
|
|
static inline int bitmap_equal(const unsigned long *src1,
|
|
const unsigned long *src2, unsigned int nbits)
|
|
{
|
|
if (small_const_nbits(nbits))
|
|
return !((*src1 ^ *src2) & BITMAP_LAST_WORD_MASK(nbits));
|
|
if (__builtin_constant_p(nbits & BITMAP_MEM_MASK) &&
|
|
IS_ALIGNED(nbits, BITMAP_MEM_ALIGNMENT))
|
|
return !memcmp(src1, src2, nbits / 8);
|
|
return __bitmap_equal(src1, src2, nbits);
|
|
}
|
|
|
|
static inline int bitmap_intersects(const unsigned long *src1,
|
|
const unsigned long *src2, unsigned int nbits)
|
|
{
|
|
if (small_const_nbits(nbits))
|
|
return ((*src1 & *src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
|
|
else
|
|
return __bitmap_intersects(src1, src2, nbits);
|
|
}
|
|
|
|
static inline int bitmap_subset(const unsigned long *src1,
|
|
const unsigned long *src2, unsigned int nbits)
|
|
{
|
|
if (small_const_nbits(nbits))
|
|
return ! ((*src1 & ~(*src2)) & BITMAP_LAST_WORD_MASK(nbits));
|
|
else
|
|
return __bitmap_subset(src1, src2, nbits);
|
|
}
|
|
|
|
static inline int bitmap_empty(const unsigned long *src, unsigned nbits)
|
|
{
|
|
if (small_const_nbits(nbits))
|
|
return ! (*src & BITMAP_LAST_WORD_MASK(nbits));
|
|
|
|
return find_first_bit(src, nbits) == nbits;
|
|
}
|
|
|
|
static inline int bitmap_full(const unsigned long *src, unsigned int nbits)
|
|
{
|
|
if (small_const_nbits(nbits))
|
|
return ! (~(*src) & BITMAP_LAST_WORD_MASK(nbits));
|
|
|
|
return find_first_zero_bit(src, nbits) == nbits;
|
|
}
|
|
|
|
static __always_inline int bitmap_weight(const unsigned long *src, unsigned int nbits)
|
|
{
|
|
if (small_const_nbits(nbits))
|
|
return hweight_long(*src & BITMAP_LAST_WORD_MASK(nbits));
|
|
return __bitmap_weight(src, nbits);
|
|
}
|
|
|
|
static __always_inline void bitmap_set(unsigned long *map, unsigned int start,
|
|
unsigned int nbits)
|
|
{
|
|
if (__builtin_constant_p(nbits) && nbits == 1)
|
|
__set_bit(start, map);
|
|
else if (__builtin_constant_p(start & BITMAP_MEM_MASK) &&
|
|
IS_ALIGNED(start, BITMAP_MEM_ALIGNMENT) &&
|
|
__builtin_constant_p(nbits & BITMAP_MEM_MASK) &&
|
|
IS_ALIGNED(nbits, BITMAP_MEM_ALIGNMENT))
|
|
memset((char *)map + start / 8, 0xff, nbits / 8);
|
|
else
|
|
__bitmap_set(map, start, nbits);
|
|
}
|
|
|
|
static __always_inline void bitmap_clear(unsigned long *map, unsigned int start,
|
|
unsigned int nbits)
|
|
{
|
|
if (__builtin_constant_p(nbits) && nbits == 1)
|
|
__clear_bit(start, map);
|
|
else if (__builtin_constant_p(start & BITMAP_MEM_MASK) &&
|
|
IS_ALIGNED(start, BITMAP_MEM_ALIGNMENT) &&
|
|
__builtin_constant_p(nbits & BITMAP_MEM_MASK) &&
|
|
IS_ALIGNED(nbits, BITMAP_MEM_ALIGNMENT))
|
|
memset((char *)map + start / 8, 0, nbits / 8);
|
|
else
|
|
__bitmap_clear(map, start, nbits);
|
|
}
|
|
|
|
static inline void bitmap_shift_right(unsigned long *dst, const unsigned long *src,
|
|
unsigned int shift, unsigned int nbits)
|
|
{
|
|
if (small_const_nbits(nbits))
|
|
*dst = (*src & BITMAP_LAST_WORD_MASK(nbits)) >> shift;
|
|
else
|
|
__bitmap_shift_right(dst, src, shift, nbits);
|
|
}
|
|
|
|
static inline void bitmap_shift_left(unsigned long *dst, const unsigned long *src,
|
|
unsigned int shift, unsigned int nbits)
|
|
{
|
|
if (small_const_nbits(nbits))
|
|
*dst = (*src << shift) & BITMAP_LAST_WORD_MASK(nbits);
|
|
else
|
|
__bitmap_shift_left(dst, src, shift, nbits);
|
|
}
|
|
|
|
static inline int bitmap_parse(const char *buf, unsigned int buflen,
|
|
unsigned long *maskp, int nmaskbits)
|
|
{
|
|
return __bitmap_parse(buf, buflen, 0, maskp, nmaskbits);
|
|
}
|
|
|
|
/**
|
|
* BITMAP_FROM_U64() - Represent u64 value in the format suitable for bitmap.
|
|
* @n: u64 value
|
|
*
|
|
* Linux bitmaps are internally arrays of unsigned longs, i.e. 32-bit
|
|
* integers in 32-bit environment, and 64-bit integers in 64-bit one.
|
|
*
|
|
* There are four combinations of endianness and length of the word in linux
|
|
* ABIs: LE64, BE64, LE32 and BE32.
|
|
*
|
|
* On 64-bit kernels 64-bit LE and BE numbers are naturally ordered in
|
|
* bitmaps and therefore don't require any special handling.
|
|
*
|
|
* On 32-bit kernels 32-bit LE ABI orders lo word of 64-bit number in memory
|
|
* prior to hi, and 32-bit BE orders hi word prior to lo. The bitmap on the
|
|
* other hand is represented as an array of 32-bit words and the position of
|
|
* bit N may therefore be calculated as: word #(N/32) and bit #(N%32) in that
|
|
* word. For example, bit #42 is located at 10th position of 2nd word.
|
|
* It matches 32-bit LE ABI, and we can simply let the compiler store 64-bit
|
|
* values in memory as it usually does. But for BE we need to swap hi and lo
|
|
* words manually.
|
|
*
|
|
* With all that, the macro BITMAP_FROM_U64() does explicit reordering of hi and
|
|
* lo parts of u64. For LE32 it does nothing, and for BE environment it swaps
|
|
* hi and lo words, as is expected by bitmap.
|
|
*/
|
|
#if __BITS_PER_LONG == 64
|
|
#define BITMAP_FROM_U64(n) (n)
|
|
#else
|
|
#define BITMAP_FROM_U64(n) ((unsigned long) ((u64)(n) & ULONG_MAX)), \
|
|
((unsigned long) ((u64)(n) >> 32))
|
|
#endif
|
|
|
|
/**
|
|
* bitmap_from_u64 - Check and swap words within u64.
|
|
* @mask: source bitmap
|
|
* @dst: destination bitmap
|
|
*
|
|
* In 32-bit Big Endian kernel, when using ``(u32 *)(&val)[*]``
|
|
* to read u64 mask, we will get the wrong word.
|
|
* That is ``(u32 *)(&val)[0]`` gets the upper 32 bits,
|
|
* but we expect the lower 32-bits of u64.
|
|
*/
|
|
static inline void bitmap_from_u64(unsigned long *dst, u64 mask)
|
|
{
|
|
dst[0] = mask & ULONG_MAX;
|
|
|
|
if (sizeof(mask) > sizeof(unsigned long))
|
|
dst[1] = mask >> 32;
|
|
}
|
|
|
|
#endif /* __ASSEMBLY__ */
|
|
|
|
#endif /* __LINUX_BITMAP_H */
|