1 /*
2  * arch/arm/include/asm/pgtable-3level.h
3  *
4  * Copyright (C) 2011 ARM Ltd.
5  * Author: Catalin Marinas <catalin.marinas@arm.com>
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License version 2 as
9  * published by the Free Software Foundation.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program; if not, write to the Free Software
18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19  */
20 #ifndef _ASM_PGTABLE_3LEVEL_H
21 #define _ASM_PGTABLE_3LEVEL_H
22 
23 /*
24  * With LPAE, there are 3 levels of page tables. Each level has 512 entries of
25  * 8 bytes each, occupying a 4K page. The first level table covers a range of
26  * 512GB, each entry representing 1GB. Since we are limited to 4GB input
27  * address range, only 4 entries in the PGD are used.
28  *
29  * There are enough spare bits in a page table entry for the kernel specific
30  * state.
31  */
32 #define PTRS_PER_PTE		512
33 #define PTRS_PER_PMD		512
34 #define PTRS_PER_PGD		4
35 
36 #define PTE_HWTABLE_PTRS	(PTRS_PER_PTE)
37 #define PTE_HWTABLE_OFF		(0)
38 #define PTE_HWTABLE_SIZE	(PTRS_PER_PTE * sizeof(u64))
39 
40 /*
41  * PGDIR_SHIFT determines the size a top-level page table entry can map.
42  */
43 #define PGDIR_SHIFT		30
44 
45 /*
46  * PMD_SHIFT determines the size a middle-level page table entry can map.
47  */
48 #define PMD_SHIFT		21
49 
50 #define PMD_SIZE		(1UL << PMD_SHIFT)
51 #define PMD_MASK		(~(PMD_SIZE-1))
52 #define PGDIR_SIZE		(1UL << PGDIR_SHIFT)
53 #define PGDIR_MASK		(~(PGDIR_SIZE-1))
54 
55 /*
56  * section address mask and size definitions.
57  */
58 #define SECTION_SHIFT		21
59 #define SECTION_SIZE		(1UL << SECTION_SHIFT)
60 #define SECTION_MASK		(~(SECTION_SIZE-1))
61 
62 #define USER_PTRS_PER_PGD	(PAGE_OFFSET / PGDIR_SIZE)
63 
64 /*
65  * "Linux" PTE definitions for LPAE.
66  *
67  * These bits overlap with the hardware bits but the naming is preserved for
68  * consistency with the classic page table format.
69  */
70 #define L_PTE_VALID		(_AT(pteval_t, 1) << 0)		/* Valid */
71 #define L_PTE_PRESENT		(_AT(pteval_t, 3) << 0)		/* Present */
72 #define L_PTE_FILE		(_AT(pteval_t, 1) << 2)		/* only when !PRESENT */
73 #define L_PTE_USER		(_AT(pteval_t, 1) << 6)		/* AP[1] */
74 #define L_PTE_RDONLY		(_AT(pteval_t, 1) << 7)		/* AP[2] */
75 #define L_PTE_SHARED		(_AT(pteval_t, 3) << 8)		/* SH[1:0], inner shareable */
76 #define L_PTE_YOUNG		(_AT(pteval_t, 1) << 10)	/* AF */
77 #define L_PTE_XN		(_AT(pteval_t, 1) << 54)	/* XN */
78 #define L_PTE_DIRTY		(_AT(pteval_t, 1) << 55)	/* unused */
79 #define L_PTE_SPECIAL		(_AT(pteval_t, 1) << 56)	/* unused */
80 #define L_PTE_NONE		(_AT(pteval_t, 1) << 57)	/* PROT_NONE */
81 
82 /*
83  * To be used in assembly code with the upper page attributes.
84  */
85 #define L_PTE_XN_HIGH		(1 << (54 - 32))
86 #define L_PTE_DIRTY_HIGH	(1 << (55 - 32))
87 
88 /*
89  * AttrIndx[2:0] encoding (mapping attributes defined in the MAIR* registers).
90  */
91 #define L_PTE_MT_UNCACHED	(_AT(pteval_t, 0) << 2)	/* strongly ordered */
92 #define L_PTE_MT_BUFFERABLE	(_AT(pteval_t, 1) << 2)	/* normal non-cacheable */
93 #define L_PTE_MT_WRITETHROUGH	(_AT(pteval_t, 2) << 2)	/* normal inner write-through */
94 #define L_PTE_MT_WRITEBACK	(_AT(pteval_t, 3) << 2)	/* normal inner write-back */
95 #define L_PTE_MT_WRITEALLOC	(_AT(pteval_t, 7) << 2)	/* normal inner write-alloc */
96 #define L_PTE_MT_DEV_SHARED	(_AT(pteval_t, 4) << 2)	/* device */
97 #define L_PTE_MT_DEV_NONSHARED	(_AT(pteval_t, 4) << 2)	/* device */
98 #define L_PTE_MT_DEV_WC		(_AT(pteval_t, 1) << 2)	/* normal non-cacheable */
99 #define L_PTE_MT_DEV_CACHED	(_AT(pteval_t, 3) << 2)	/* normal inner write-back */
100 #define L_PTE_MT_MASK		(_AT(pteval_t, 7) << 2)
101 
102 /*
103  * Software PGD flags.
104  */
105 #define L_PGD_SWAPPER		(_AT(pgdval_t, 1) << 55)	/* swapper_pg_dir entry */
106 
107 /*
108  * 2nd stage PTE definitions for LPAE.
109  */
110 #define L_PTE_S2_MT_UNCACHED	 (_AT(pteval_t, 0x5) << 2) /* MemAttr[3:0] */
111 #define L_PTE_S2_MT_WRITETHROUGH (_AT(pteval_t, 0xa) << 2) /* MemAttr[3:0] */
112 #define L_PTE_S2_MT_WRITEBACK	 (_AT(pteval_t, 0xf) << 2) /* MemAttr[3:0] */
113 #define L_PTE_S2_RDONLY		 (_AT(pteval_t, 1) << 6)   /* HAP[1]   */
114 #define L_PTE_S2_RDWR		 (_AT(pteval_t, 3) << 6)   /* HAP[2:1] */
115 
116 /*
117  * Hyp-mode PL2 PTE definitions for LPAE.
118  */
119 #define L_PTE_HYP		L_PTE_USER
120 
121 #ifndef __ASSEMBLY__
122 
123 #define pud_none(pud)		(!pud_val(pud))
124 #define pud_bad(pud)		(!(pud_val(pud) & 2))
125 #define pud_present(pud)	(pud_val(pud))
126 #define pmd_table(pmd)		((pmd_val(pmd) & PMD_TYPE_MASK) == \
127 						 PMD_TYPE_TABLE)
128 #define pmd_sect(pmd)		((pmd_val(pmd) & PMD_TYPE_MASK) == \
129 						 PMD_TYPE_SECT)
130 
131 #define pud_clear(pudp)			\
132 	do {				\
133 		*pudp = __pud(0);	\
134 		clean_pmd_entry(pudp);	\
135 	} while (0)
136 
137 #define set_pud(pudp, pud)		\
138 	do {				\
139 		*pudp = pud;		\
140 		flush_pmd_entry(pudp);	\
141 	} while (0)
142 
143 static inline pmd_t *pud_page_vaddr(pud_t pud)
144 {
145 	return __va(pud_val(pud) & PHYS_MASK & (s32)PAGE_MASK);
146 }
147 
148 /* Find an entry in the second-level page table.. */
149 #define pmd_index(addr)		(((addr) >> PMD_SHIFT) & (PTRS_PER_PMD - 1))
150 static inline pmd_t *pmd_offset(pud_t *pud, unsigned long addr)
151 {
152 	return (pmd_t *)pud_page_vaddr(*pud) + pmd_index(addr);
153 }
154 
155 #define pmd_bad(pmd)		(!(pmd_val(pmd) & 2))
156 
157 #define copy_pmd(pmdpd,pmdps)		\
158 	do {				\
159 		*pmdpd = *pmdps;	\
160 		flush_pmd_entry(pmdpd);	\
161 	} while (0)
162 
163 #define pmd_clear(pmdp)			\
164 	do {				\
165 		*pmdp = __pmd(0);	\
166 		clean_pmd_entry(pmdp);	\
167 	} while (0)
168 
169 #define set_pte_ext(ptep,pte,ext) cpu_set_pte_ext(ptep,__pte(pte_val(pte)|(ext)))
170 
171 #endif /* __ASSEMBLY__ */
172 
173 #endif /* _ASM_PGTABLE_3LEVEL_H */
174