idmap_pgd
extern pgd_t *idmap_pgd;
cpu_switch_mm(idmap_pgd, &init_mm);
secondary_data.pgdir = virt_to_phys(idmap_pgd);
if (!idmap_pgd)
*ptr++ = virt_to_phys(idmap_pgd);
idmap_pgd = pgd_alloc(&init_mm);
if (!idmap_pgd)
identity_mapping_add(idmap_pgd, __idmap_text_start,
cpu_switch_mm(idmap_pgd, &init_mm);
pgd_t *idmap_pgd __ro_after_init;