kernel_unmap_pages_in_pgd
extern int __init kernel_unmap_pages_in_pgd(pgd_t *pgd, unsigned long address,
if (kernel_unmap_pages_in_pgd(pgd, text, npages)) {
if (kernel_unmap_pages_in_pgd(pgd, pa, md->num_pages))
if (kernel_unmap_pages_in_pgd(pgd, va, md->num_pages))