diff options
Diffstat (limited to 'include/linux/bitmap.h')
-rw-r--r-- | include/linux/bitmap.h | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/include/linux/bitmap.h b/include/linux/bitmap.h index 29fc933df3bf..9f046609e809 100644 --- a/include/linux/bitmap.h +++ b/include/linux/bitmap.h @@ -66,6 +66,8 @@ * 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 + * bitmap_get_value8(map, start) Get 8bit value from map at start + * bitmap_set_value8(map, value, start) Set 8bit value to map at start * * Note, bitmap_zero() and bitmap_fill() operate over the region of * unsigned longs, that is, bits behind bitmap till the unsigned long @@ -489,6 +491,39 @@ static inline void bitmap_from_u64(unsigned long *dst, u64 mask) dst[1] = mask >> 32; } +/** + * bitmap_get_value8 - get an 8-bit value within a memory region + * @map: address to the bitmap memory region + * @start: bit offset of the 8-bit value; must be a multiple of 8 + * + * Returns the 8-bit value located at the @start bit offset within the @src + * memory region. + */ +static inline unsigned long bitmap_get_value8(const unsigned long *map, + unsigned long start) +{ + const size_t index = BIT_WORD(start); + const unsigned long offset = start % BITS_PER_LONG; + + return (map[index] >> offset) & 0xFF; +} + +/** + * bitmap_set_value8 - set an 8-bit value within a memory region + * @map: address to the bitmap memory region + * @value: the 8-bit value; values wider than 8 bits may clobber bitmap + * @start: bit offset of the 8-bit value; must be a multiple of 8 + */ +static inline void bitmap_set_value8(unsigned long *map, unsigned long value, + unsigned long start) +{ + const size_t index = BIT_WORD(start); + const unsigned long offset = start % BITS_PER_LONG; + + map[index] &= ~(0xFFUL << offset); + map[index] |= value << offset; +} + #endif /* __ASSEMBLY__ */ #endif /* __LINUX_BITMAP_H */ |