xref: /openbmc/linux/arch/hexagon/include/asm/vm_mmu.h (revision 4f6cce39)
1 /*
2  * Hexagon VM page table entry definitions
3  *
4  * Copyright (c) 2010-2011,2013 The Linux Foundation. All rights reserved.
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License version 2 and
8  * only version 2 as published by the Free Software Foundation.
9  *
10  * This program is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13  * GNU General Public License for more details.
14  *
15  * You should have received a copy of the GNU General Public License
16  * along with this program; if not, write to the Free Software
17  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
18  * 02110-1301, USA.
19  */
20 
21 #ifndef _ASM_VM_MMU_H
22 #define _ASM_VM_MMU_H
23 
24 /*
25  * Shift, mask, and other constants for the Hexagon Virtual Machine
26  * page tables.
27  *
28  * Virtual machine MMU allows first-level entries to either be
29  * single-level lookup PTEs for very large pages, or PDEs pointing
30  * to second-level PTEs for smaller pages. If PTE is single-level,
31  * the least significant bits cannot be used as software bits to encode
32  * virtual memory subsystem information about the page, and that state
33  * must be maintained in some parallel data structure.
34  */
35 
36 /* S or Page Size field in PDE */
37 #define	__HVM_PDE_S		(0x7 << 0)
38 #define __HVM_PDE_S_4KB		0
39 #define __HVM_PDE_S_16KB	1
40 #define __HVM_PDE_S_64KB	2
41 #define __HVM_PDE_S_256KB	3
42 #define __HVM_PDE_S_1MB		4
43 #define __HVM_PDE_S_4MB		5
44 #define __HVM_PDE_S_16MB	6
45 #define __HVM_PDE_S_INVALID	7
46 
47 /* Masks for L2 page table pointer, as function of page size */
48 #define __HVM_PDE_PTMASK_4KB	0xfffff000
49 #define __HVM_PDE_PTMASK_16KB	0xfffffc00
50 #define __HVM_PDE_PTMASK_64KB	0xffffff00
51 #define __HVM_PDE_PTMASK_256KB	0xffffffc0
52 #define __HVM_PDE_PTMASK_1MB	0xfffffff0
53 
54 /*
55  * Virtual Machine PTE Bits/Fields
56  */
57 #define __HVM_PTE_T		(1<<4)
58 #define __HVM_PTE_U		(1<<5)
59 #define	__HVM_PTE_C		(0x7<<6)
60 #define __HVM_PTE_CVAL(pte)	(((pte) & __HVM_PTE_C) >> 6)
61 #define __HVM_PTE_R		(1<<9)
62 #define __HVM_PTE_W		(1<<10)
63 #define __HVM_PTE_X		(1<<11)
64 
65 /*
66  * Cache Attributes, to be shifted as necessary for virtual/physical PTEs
67  */
68 
69 #define __HEXAGON_C_WB		0x0	/* Write-back, no L2 */
70 #define	__HEXAGON_C_WT		0x1	/* Write-through, no L2 */
71 #define	__HEXAGON_C_UNC		0x6	/* Uncached memory */
72 #if CONFIG_HEXAGON_ARCH_VERSION >= 2
73 #define	__HEXAGON_C_DEV		0x4	/* Device register space */
74 #else
75 #define __HEXAGON_C_DEV		__HEXAGON_C_UNC
76 #endif
77 #define	__HEXAGON_C_WT_L2	0x5	/* Write-through, with L2 */
78 #define	__HEXAGON_C_WB_L2	0x7	/* Write-back, with L2 */
79 
80 /*
81  * This can be overridden, but we're defaulting to the most aggressive
82  * cache policy, the better to find bugs sooner.
83  */
84 
85 #define	CACHE_DEFAULT	__HEXAGON_C_WB_L2
86 
87 /* Masks for physical page address, as a function of page size */
88 
89 #define __HVM_PTE_PGMASK_4KB	0xfffff000
90 #define __HVM_PTE_PGMASK_16KB	0xffffc000
91 #define __HVM_PTE_PGMASK_64KB	0xffff0000
92 #define __HVM_PTE_PGMASK_256KB	0xfffc0000
93 #define __HVM_PTE_PGMASK_1MB	0xfff00000
94 
95 /* Masks for single-level large page lookups */
96 
97 #define __HVM_PTE_PGMASK_4MB	0xffc00000
98 #define __HVM_PTE_PGMASK_16MB	0xff000000
99 
100 /*
101  * "Big kernel page mappings" (see vm_init_segtable.S)
102  * are currently 16MB
103  */
104 
105 #define BIG_KERNEL_PAGE_SHIFT 24
106 #define BIG_KERNEL_PAGE_SIZE (1 << BIG_KERNEL_PAGE_SHIFT)
107 
108 
109 
110 #endif /* _ASM_VM_MMU_H */
111