diff options
Diffstat (limited to 'arch/nios2/include/asm/pgtable-bits.h')
| -rw-r--r-- | arch/nios2/include/asm/pgtable-bits.h | 37 |
1 files changed, 37 insertions, 0 deletions
diff --git a/arch/nios2/include/asm/pgtable-bits.h b/arch/nios2/include/asm/pgtable-bits.h new file mode 100644 index 0000000000..724f9b08b1 --- /dev/null +++ b/arch/nios2/include/asm/pgtable-bits.h @@ -0,0 +1,37 @@ +/* + * 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 */ |