xref: /linux/arch/riscv/include/asm/pgtable-bits.h (revision 8137a49e1567726eb10fcf55ad141ac19804ca6b)
1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * Copyright (C) 2012 Regents of the University of California
4  */
5 
6 #ifndef _ASM_RISCV_PGTABLE_BITS_H
7 #define _ASM_RISCV_PGTABLE_BITS_H
8 
9 /*
10  * PTE format:
11  * | XLEN-1  10 | 9             8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0
12  *       PFN      reserved for SW   D   A   G   U   X   W   R   V
13  */
14 
15 #define _PAGE_ACCESSED_OFFSET 6
16 
17 #define _PAGE_PRESENT   (1 << 0)
18 #define _PAGE_READ      (1 << 1)    /* Readable */
19 #define _PAGE_WRITE     (1 << 2)    /* Writable */
20 #define _PAGE_EXEC      (1 << 3)    /* Executable */
21 #define _PAGE_USER      (1 << 4)    /* User */
22 #define _PAGE_GLOBAL    (1 << 5)    /* Global */
23 #define _PAGE_ACCESSED  (1 << 6)    /* Set by hardware on any access */
24 #define _PAGE_DIRTY     (1 << 7)    /* Set by hardware on any write */
25 #define _PAGE_SOFT      (1 << 8)    /* Reserved for software */
26 
27 #define _PAGE_SPECIAL   _PAGE_SOFT
28 #define _PAGE_TABLE     _PAGE_PRESENT
29 
30 /*
31  * _PAGE_PROT_NONE is set on not-present pages (and ignored by the hardware) to
32  * distinguish them from swapped out pages
33  */
34 #define _PAGE_PROT_NONE _PAGE_READ
35 
36 #define _PAGE_PFN_SHIFT 10
37 
38 /* Set of bits to preserve across pte_modify() */
39 #define _PAGE_CHG_MASK  (~(unsigned long)(_PAGE_PRESENT | _PAGE_READ |	\
40 					  _PAGE_WRITE | _PAGE_EXEC |	\
41 					  _PAGE_USER | _PAGE_GLOBAL))
42 /*
43  * when all of R/W/X are zero, the PTE is a pointer to the next level
44  * of the page table; otherwise, it is a leaf PTE.
45  */
46 #define _PAGE_LEAF (_PAGE_READ | _PAGE_WRITE | _PAGE_EXEC)
47 
48 #endif /* _ASM_RISCV_PGTABLE_BITS_H */
49