_PAGE_RONLY
static inline int pte_write(pte_t pte) { return !(pte_val(pte) & _PAGE_RONLY); }
static inline pte_t pte_wrprotect(pte_t pte) { pte_val(pte) |= _PAGE_RONLY; return pte; }
static inline pte_t pte_mkwrite_novma(pte_t pte){ pte_val(pte) &= ~_PAGE_RONLY; return pte; }
#define PAGE_COPY __pgprot(_PAGE_PRESENT | _PAGE_RONLY | _PAGE_ACCESSED | mm_cachebits)
#define PAGE_READONLY __pgprot(_PAGE_PRESENT | _PAGE_RONLY | _PAGE_ACCESSED | mm_cachebits)
#define PAGE_COPY_C __pgprot(_PAGE_PRESENT | _PAGE_RONLY | _PAGE_ACCESSED)
#define PAGE_READONLY_C __pgprot(_PAGE_PRESENT | _PAGE_RONLY | _PAGE_ACCESSED)