zfs_map_page
va = zfs_map_page(pp, S_READ);
extern caddr_t zfs_map_page(page_t *, enum seg_rw);
caddr_t va = zfs_map_page(pp, S_READ);
va = zfs_map_page(cur_pp, S_WRITE);
va = zfs_map_page(pp, S_WRITE);
va = zfs_map_page(pp, S_READ);