SB_NR_TO_INDEX
index = SB_NR_TO_INDEX(sb, start);
return &sb->map[SB_NR_TO_INDEX(sb, bitnr)].word;
unsigned long *addr = &sb->map[SB_NR_TO_INDEX(sb, bitnr)].cleared;
index = SB_NR_TO_INDEX(sb, alloc_hint);
index = SB_NR_TO_INDEX(sb, alloc_hint);
index = SB_NR_TO_INDEX(sb, hint);
this_addr = &sb->map[SB_NR_TO_INDEX(sb, tag)].word;