pm_num_pages
p->pm_rx_num_pgs = pm_num_pages(p->pm_size - p->pm_rx_base,
p->pm_tx_num_pgs = pm_num_pages(p->pm_rx_base - p->pm_tx_base,
num = pm_num_pages(p->pm_size - p->pm_rx_base, p->pm_rx_pg_size);
num = pm_num_pages(p->pm_rx_base - p->pm_tx_base, p->pm_tx_pg_size);