Logical left shift of the bits in a bitmap
void __bitmap_shift_left(unsigned long * dst, const unsigned long * src, int shift, int bits);
dst
destination bitmap
src
source bitmap
shift
shift by this many bits
bits
bitmap size, in bits
Shifting left (multiplying) means moving bits in the LS -> MS direction. Zeros are fed into the vacated LS bit positions and those MS bits shifted off the top are lost.