xref: /openbmc/linux/arch/sh/include/asm/pgtable.h (revision 3db55767)
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 __ASSEMBLY__
21 #include <asm/addrspace.h>
22 #include <asm/fixmap.h>
23 
24 /*
25  * ZERO_PAGE is a global shared page that is always zero: used
26  * for zero-mapped memory areas etc..
27  */
28 extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)];
29 #define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page))
30 
31 #endif /* !__ASSEMBLY__ */
32 
33 /*
34  * Effective and physical address definitions, to aid with sign
35  * extension.
36  */
37 #define NEFF		32
38 #define	NEFF_SIGN	(1LL << (NEFF - 1))
39 #define	NEFF_MASK	(-1LL << NEFF)
40 
41 static inline unsigned long long neff_sign_extend(unsigned long val)
42 {
43 	unsigned long long extended = val;
44 	return (extended & NEFF_SIGN) ? (extended | NEFF_MASK) : extended;
45 }
46 
47 #ifdef CONFIG_29BIT
48 #define NPHYS		29
49 #else
50 #define NPHYS		32
51 #endif
52 
53 #define	NPHYS_SIGN	(1LL << (NPHYS - 1))
54 #define	NPHYS_MASK	(-1LL << NPHYS)
55 
56 #define PGDIR_SIZE	(1UL << PGDIR_SHIFT)
57 #define PGDIR_MASK	(~(PGDIR_SIZE-1))
58 
59 /* Entries per level */
60 #define PTRS_PER_PTE	(PAGE_SIZE / (1 << PTE_MAGNITUDE))
61 
62 #define PHYS_ADDR_MASK29		0x1fffffff
63 #define PHYS_ADDR_MASK32		0xffffffff
64 
65 static inline unsigned long phys_addr_mask(void)
66 {
67 	/* Is the MMU in 29bit mode? */
68 	if (__in_29bit_mode())
69 		return PHYS_ADDR_MASK29;
70 
71 	return PHYS_ADDR_MASK32;
72 }
73 
74 #define PTE_PHYS_MASK		(phys_addr_mask() & PAGE_MASK)
75 #define PTE_FLAGS_MASK		(~(PTE_PHYS_MASK) << PAGE_SHIFT)
76 
77 #define VMALLOC_START	(P3SEG)
78 #define VMALLOC_END	(FIXADDR_START-2*PAGE_SIZE)
79 
80 #include <asm/pgtable_32.h>
81 
82 /*
83  * SH-X and lower (legacy) SuperH parts (SH-3, SH-4, some SH-4A) can't do page
84  * protection for execute, and considers it the same as a read. Also, write
85  * permission implies read permission. This is the closest we can get..
86  *
87  * SH-X2 (SH7785) and later parts take this to the opposite end of the extreme,
88  * not only supporting separate execute, read, and write bits, but having
89  * completely separate permission bits for user and kernel space.
90  */
91 	 /*xwr*/
92 
93 typedef pte_t *pte_addr_t;
94 
95 #define pte_pfn(x)		((unsigned long)(((x).pte_low >> PAGE_SHIFT)))
96 
97 struct vm_area_struct;
98 struct mm_struct;
99 
100 extern void __update_cache(struct vm_area_struct *vma,
101 			   unsigned long address, pte_t pte);
102 extern void __update_tlb(struct vm_area_struct *vma,
103 			 unsigned long address, pte_t pte);
104 
105 static inline void
106 update_mmu_cache(struct vm_area_struct *vma, unsigned long address, pte_t *ptep)
107 {
108 	pte_t pte = *ptep;
109 	__update_cache(vma, address, pte);
110 	__update_tlb(vma, address, pte);
111 }
112 
113 extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
114 extern void paging_init(void);
115 extern void page_table_range_init(unsigned long start, unsigned long end,
116 				  pgd_t *pgd);
117 
118 static inline bool __pte_access_permitted(pte_t pte, u64 prot)
119 {
120 	return (pte_val(pte) & (prot | _PAGE_SPECIAL)) == prot;
121 }
122 
123 #ifdef CONFIG_X2TLB
124 static inline bool pte_access_permitted(pte_t pte, bool write)
125 {
126 	u64 prot = _PAGE_PRESENT;
127 
128 	prot |= _PAGE_EXT(_PAGE_EXT_KERN_READ | _PAGE_EXT_USER_READ);
129 	if (write)
130 		prot |= _PAGE_EXT(_PAGE_EXT_KERN_WRITE | _PAGE_EXT_USER_WRITE);
131 	return __pte_access_permitted(pte, prot);
132 }
133 #else
134 static inline bool pte_access_permitted(pte_t pte, bool write)
135 {
136 	u64 prot = _PAGE_PRESENT | _PAGE_USER;
137 
138 	if (write)
139 		prot |= _PAGE_RW;
140 	return __pte_access_permitted(pte, prot);
141 }
142 #endif
143 
144 #define pte_access_permitted pte_access_permitted
145 
146 /* arch/sh/mm/mmap.c */
147 #define HAVE_ARCH_UNMAPPED_AREA
148 #define HAVE_ARCH_UNMAPPED_AREA_TOPDOWN
149 
150 #endif /* __ASM_SH_PGTABLE_H */
151