diff options
Diffstat (limited to 'include/linux/bitmap.h')
| -rw-r--r-- | include/linux/bitmap.h | 63 |
1 files changed, 47 insertions, 16 deletions
diff --git a/include/linux/bitmap.h b/include/linux/bitmap.h index 3489253e38fc..49aea0b37994 100644 --- a/include/linux/bitmap.h +++ b/include/linux/bitmap.h @@ -64,9 +64,14 @@ * 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_u32array(dst, nbits, buf, nwords) *dst = *buf (nwords 32b words) - * bitmap_to_u32array(buf, nwords, src, nbits) *buf = *dst (nwords 32b words) + * 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. */ /** @@ -83,8 +88,12 @@ * 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_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) * */ @@ -174,14 +183,7 @@ extern void bitmap_fold(unsigned long *dst, const unsigned long *orig, 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); -extern unsigned int bitmap_from_u32array(unsigned long *bitmap, - unsigned int nbits, - const u32 *buf, - unsigned int nwords); -extern unsigned int bitmap_to_u32array(u32 *buf, - unsigned int nwords, - const unsigned long *bitmap, - unsigned int nbits); + #ifdef __BIG_ENDIAN extern void bitmap_copy_le(unsigned long *dst, const unsigned long *src, unsigned int nbits); #else @@ -209,12 +211,12 @@ static inline void bitmap_zero(unsigned long *dst, unsigned int nbits) static inline void bitmap_fill(unsigned long *dst, unsigned int nbits) { - unsigned int nlongs = BITS_TO_LONGS(nbits); - if (!small_const_nbits(nbits)) { - unsigned int len = (nlongs - 1) * sizeof(unsigned long); - memset(dst, 0xff, len); + if (small_const_nbits(nbits)) + *dst = ~0UL; + else { + unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long); + memset(dst, 0xff, len); } - dst[nlongs - 1] = BITMAP_LAST_WORD_MASK(nbits); } static inline void bitmap_copy(unsigned long *dst, const unsigned long *src, @@ -228,6 +230,35 @@ static inline void bitmap_copy(unsigned long *dst, const unsigned long *src, } } +/* + * Copy bitmap and clear tail bits in last word. + */ +static inline void bitmap_copy_safe(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_safe((unsigned long *) (bitmap), \ + (const unsigned long *) (buf), (nbits)) +#define bitmap_to_arr32(buf, bitmap, nbits) \ + bitmap_copy_safe((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) { |