xref: /linux/arch/sh/include/asm/pgtable.h (revision e2683c8868d03382da7e1ce8453b543a043066d1)
1 /* SPDX-License-Identifier: GPL-2.0
2  *
3  * This file contains the functions and defines necessary to modify and
4  * use the SuperH page table tree.
5  *
6  * Copyright (C) 1999 Niibe Yutaka
7  * Copyright (C) 2002 - 2007 Paul Mundt
8  */
9 #ifndef __ASM_SH_PGTABLE_H
10 #define __ASM_SH_PGTABLE_H
11 
12 #ifdef CONFIG_X2TLB
13 #include <asm/pgtable-3level.h>
14 #else
15 #include <asm/pgtable-2level.h>
16 #endif
17 #include <asm/page.h>
18 #include <asm/mmu.h>
19 
20 #ifndef __ASSEMBLER__
21 #include <asm/addrspace.h>
22 #include <asm/fixmap.h>
23 #endif /* !__ASSEMBLER__ */
24 
25 /*
26  * Effective and physical address definitions, to aid with sign
27  * extension.
28  */
29 #define NEFF		32
30 #define	NEFF_SIGN	(1LL << (NEFF - 1))
31 #define	NEFF_MASK	(-1LL << NEFF)
32 
33 static inline unsigned long long neff_sign_extend(unsigned long val)
34 {
35 	unsigned long long extended = val;
36 	return (extended & NEFF_SIGN) ? (extended | NEFF_MASK) : extended;
37 }
38 
39 #ifdef CONFIG_29BIT
40 #define NPHYS		29
41 #else
42 #define NPHYS		32
43 #endif
44 
45 #define	NPHYS_SIGN	(1LL << (NPHYS - 1))
46 #define	NPHYS_MASK	(-1LL << NPHYS)
47 
48 #define PGDIR_SIZE	(1UL << PGDIR_SHIFT)
49 #define PGDIR_MASK	(~(PGDIR_SIZE-1))
50 
51 /* Entries per level */
52 #define PTRS_PER_PTE	(PAGE_SIZE / (1 << PTE_MAGNITUDE))
53 
54 #define PHYS_ADDR_MASK29		0x1fffffff
55 #define PHYS_ADDR_MASK32		0xffffffff
56 
57 static inline unsigned long phys_addr_mask(void)
58 {
59 	/* Is the MMU in 29bit mode? */
60 	if (__in_29bit_mode())
61 		return PHYS_ADDR_MASK29;
62 
63 	return PHYS_ADDR_MASK32;
64 }
65 
66 #define PTE_PHYS_MASK		(phys_addr_mask() & PAGE_MASK)
67 #define PTE_FLAGS_MASK		(~(PTE_PHYS_MASK) << PAGE_SHIFT)
68 
69 #define VMALLOC_START	(P3SEG)
70 #define VMALLOC_END	(FIXADDR_START-2*PAGE_SIZE)
71 
72 #include <asm/pgtable_32.h>
73 
74 /*
75  * SH-X and lower (legacy) SuperH parts (SH-3, SH-4, some SH-4A) can't do page
76  * protection for execute, and considers it the same as a read. Also, write
77  * permission implies read permission. This is the closest we can get..
78  *
79  * SH-X2 (SH7785) and later parts take this to the opposite end of the extreme,
80  * not only supporting separate execute, read, and write bits, but having
81  * completely separate permission bits for user and kernel space.
82  */
83 	 /*xwr*/
84 
85 typedef pte_t *pte_addr_t;
86 
87 #define pte_pfn(x)		((unsigned long)(((x).pte_low >> PAGE_SHIFT)))
88 
89 struct vm_area_struct;
90 struct mm_struct;
91 
92 extern void __update_cache(struct vm_area_struct *vma,
93 			   unsigned long address, pte_t pte);
94 extern void __update_tlb(struct vm_area_struct *vma,
95 			 unsigned long address, pte_t pte);
96 
97 static inline void update_mmu_cache_range(struct vm_fault *vmf,
98 		struct vm_area_struct *vma, unsigned long address,
99 		pte_t *ptep, unsigned int nr)
100 {
101 	pte_t pte = *ptep;
102 	__update_cache(vma, address, pte);
103 	__update_tlb(vma, address, pte);
104 }
105 #define update_mmu_cache(vma, addr, ptep) \
106 	update_mmu_cache_range(NULL, vma, addr, ptep, 1)
107 
108 extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
109 extern void paging_init(void);
110 extern void page_table_range_init(unsigned long start, unsigned long end,
111 				  pgd_t *pgd);
112 
113 static inline bool __pte_access_permitted(pte_t pte, u64 prot)
114 {
115 	return (pte_val(pte) & (prot | _PAGE_SPECIAL)) == prot;
116 }
117 
118 #ifdef CONFIG_X2TLB
119 static inline bool pte_access_permitted(pte_t pte, bool write)
120 {
121 	u64 prot = _PAGE_PRESENT;
122 
123 	prot |= _PAGE_EXT(_PAGE_EXT_KERN_READ | _PAGE_EXT_USER_READ);
124 	if (write)
125 		prot |= _PAGE_EXT(_PAGE_EXT_KERN_WRITE | _PAGE_EXT_USER_WRITE);
126 	return __pte_access_permitted(pte, prot);
127 }
128 #else
129 static inline bool pte_access_permitted(pte_t pte, bool write)
130 {
131 	u64 prot = _PAGE_PRESENT | _PAGE_USER;
132 
133 	if (write)
134 		prot |= _PAGE_RW;
135 	return __pte_access_permitted(pte, prot);
136 }
137 #endif
138 
139 #define pte_access_permitted pte_access_permitted
140 
141 /* arch/sh/mm/mmap.c */
142 #define HAVE_ARCH_UNMAPPED_AREA
143 #define HAVE_ARCH_UNMAPPED_AREA_TOPDOWN
144 
145 #endif /* __ASM_SH_PGTABLE_H */
146