PROT_DEVICE_nGnRE
#define FIXMAP_PAGE_IO __pgprot(PROT_DEVICE_nGnRE)
__ioremap_prot((addr), (size), __pgprot(PROT_DEVICE_nGnRE))
pgprot_t prot = __pgprot(PROT_DEVICE_nGnRE);
if (protval != PROT_DEVICE_nGnRE && protval != PROT_DEVICE_nGnRnE)