/* * Copyright (C) 2011 Tobias Klauser <tklauser@distanz.ch> * Copyright (C) 2009 Wind River Systems Inc * * This file is subject to the terms and conditions of the GNU General Public * License. See the file "COPYING" in the main directory of this archive * for more details. */ #ifndef _ASM_NIOS2_PGTABLE_BITS_H #define _ASM_NIOS2_PGTABLE_BITS_H /* * These are actual hardware defined protection bits in the tlbacc register * which looks like this: * * 31 30 ... 26 25 24 23 22 21 20 19 18 ... 1 0 * ignored........ C R W X G PFN............ */ #define _PAGE_GLOBAL (1<<20) #define _PAGE_EXEC (1<<21) #define _PAGE_WRITE (1<<22) #define _PAGE_READ (1<<23) #define _PAGE_CACHED (1<<24) /* C: data access cacheable */ /* * Software defined bits. They are ignored by the hardware and always read back * as zero, but can be written as non-zero. */ #define _PAGE_PRESENT (1<<25) /* PTE contains a translation */ #define _PAGE_ACCESSED (1<<26) /* page referenced */ #define _PAGE_DIRTY (1<<27) /* dirty page */ /* We borrow bit 31 to store the exclusive marker in swap PTEs. */ #define _PAGE_SWP_EXCLUSIVE (1<<31) #endif /* _ASM_NIOS2_PGTABLE_BITS_H */