linux/arch/nios2/include/asm/pgtable-bits.h
Ley Foon Tan cbd15b3fad nios2: Page table management
This patch adds support for page table management.

Signed-off-by: Ley Foon Tan <lftan@altera.com>
2014-12-08 12:55:53 +08:00

36 lines
1.1 KiB
C

/*
* 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 */
#define _PAGE_FILE (1<<28) /* PTE used for file mapping or swap */
#endif /* _ASM_NIOS2_PGTABLE_BITS_H */