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linux/arch/nios2/include/asm/pgtable-bits.h
David Hildenbrand 4d1d955f7c nios2/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE
Let's support __HAVE_ARCH_PTE_SWP_EXCLUSIVE by using the yet-unused bit
31.

Link: https://lkml.kernel.org/r/20230113171026.582290-15-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-02-02 22:33:08 -08:00

38 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 */
/* We borrow bit 31 to store the exclusive marker in swap PTEs. */
#define _PAGE_SWP_EXCLUSIVE (1<<31)
#endif /* _ASM_NIOS2_PGTABLE_BITS_H */