1 /* 2 * Copyright (C) 2011 Tobias Klauser <tklauser@distanz.ch> 3 * Copyright (C) 2009 Wind River Systems Inc 4 * 5 * This file is subject to the terms and conditions of the GNU General Public 6 * License. See the file "COPYING" in the main directory of this archive 7 * for more details. 8 */ 9 10 #ifndef _ASM_NIOS2_PGTABLE_BITS_H 11 #define _ASM_NIOS2_PGTABLE_BITS_H 12 13 /* 14 * These are actual hardware defined protection bits in the tlbacc register 15 * which looks like this: 16 * 17 * 31 30 ... 26 25 24 23 22 21 20 19 18 ... 1 0 18 * ignored........ C R W X G PFN............ 19 */ 20 #define _PAGE_GLOBAL (1<<20) 21 #define _PAGE_EXEC (1<<21) 22 #define _PAGE_WRITE (1<<22) 23 #define _PAGE_READ (1<<23) 24 #define _PAGE_CACHED (1<<24) /* C: data access cacheable */ 25 26 /* 27 * Software defined bits. They are ignored by the hardware and always read back 28 * as zero, but can be written as non-zero. 29 */ 30 #define _PAGE_PRESENT (1<<25) /* PTE contains a translation */ 31 #define _PAGE_ACCESSED (1<<26) /* page referenced */ 32 #define _PAGE_DIRTY (1<<27) /* dirty page */ 33 34 #endif /* _ASM_NIOS2_PGTABLE_BITS_H */ 35