1 /*
2 * Copyright (C) 2011 Tobias Klauser <tklauser@distanz.ch>
3 * Copyright (C) 2009 Wind River Systems Inc
4 *
5 * Based on asm/pgtable-32.h from mips which is:
6 *
7 * Copyright (C) 1994, 95, 96, 97, 98, 99, 2000, 2003 Ralf Baechle
8 * Copyright (C) 1999, 2000, 2001 Silicon Graphics, Inc.
9 *
10 * This file is subject to the terms and conditions of the GNU General Public
11 * License. See the file "COPYING" in the main directory of this archive
12 * for more details.
13 */
14
15 #ifndef _ASM_NIOS2_PGTABLE_H
16 #define _ASM_NIOS2_PGTABLE_H
17
18 #include <linux/io.h>
19 #include <linux/bug.h>
20 #include <asm/page.h>
21 #include <asm/cacheflush.h>
22 #include <asm/tlbflush.h>
23
24 #include <asm/pgtable-bits.h>
25 #include <asm-generic/pgtable-nopmd.h>
26
27 #define VMALLOC_START CONFIG_NIOS2_KERNEL_MMU_REGION_BASE
28 #define VMALLOC_END (CONFIG_NIOS2_KERNEL_REGION_BASE - 1)
29
30 struct mm_struct;
31
32 /* Helper macro */
33 #define MKP(x, w, r) __pgprot(_PAGE_PRESENT | _PAGE_CACHED | \
34 ((x) ? _PAGE_EXEC : 0) | \
35 ((r) ? _PAGE_READ : 0) | \
36 ((w) ? _PAGE_WRITE : 0))
37 /*
38 * These are the macros that generic kernel code needs
39 * (to populate protection_map[])
40 */
41
42 /* Remove W bit on private pages for COW support */
43
44 /* Shared pages can have exact HW mapping */
45
46 /* Used all over the kernel */
47 #define PAGE_KERNEL __pgprot(_PAGE_PRESENT | _PAGE_CACHED | _PAGE_READ | \
48 _PAGE_WRITE | _PAGE_EXEC | _PAGE_GLOBAL)
49
50 #define PAGE_SHARED __pgprot(_PAGE_PRESENT | _PAGE_CACHED | _PAGE_READ | \
51 _PAGE_WRITE | _PAGE_ACCESSED)
52
53 #define PAGE_COPY MKP(0, 0, 1)
54
55 #define PTRS_PER_PGD (PAGE_SIZE / sizeof(pgd_t))
56 #define PTRS_PER_PTE (PAGE_SIZE / sizeof(pte_t))
57
58 #define USER_PTRS_PER_PGD \
59 (CONFIG_NIOS2_KERNEL_MMU_REGION_BASE / PGDIR_SIZE)
60
61 #define PGDIR_SHIFT 22
62 #define PGDIR_SIZE (1UL << PGDIR_SHIFT)
63 #define PGDIR_MASK (~(PGDIR_SIZE-1))
64
65 /*
66 * ZERO_PAGE is a global shared page that is always zero: used
67 * for zero-mapped memory areas etc..
68 */
69 extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)];
70 #define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page))
71
72 extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
73 extern pte_t invalid_pte_table[PAGE_SIZE/sizeof(pte_t)];
74
75 /*
76 * (pmds are folded into puds so this doesn't get actually called,
77 * but the define is needed for a generic inline function.)
78 */
set_pmd(pmd_t * pmdptr,pmd_t pmdval)79 static inline void set_pmd(pmd_t *pmdptr, pmd_t pmdval)
80 {
81 *pmdptr = pmdval;
82 }
83
pte_write(pte_t pte)84 static inline int pte_write(pte_t pte) \
85 { return pte_val(pte) & _PAGE_WRITE; }
pte_dirty(pte_t pte)86 static inline int pte_dirty(pte_t pte) \
87 { return pte_val(pte) & _PAGE_DIRTY; }
pte_young(pte_t pte)88 static inline int pte_young(pte_t pte) \
89 { return pte_val(pte) & _PAGE_ACCESSED; }
90
91 #define pgprot_noncached pgprot_noncached
92
pgprot_noncached(pgprot_t _prot)93 static inline pgprot_t pgprot_noncached(pgprot_t _prot)
94 {
95 unsigned long prot = pgprot_val(_prot);
96
97 prot &= ~_PAGE_CACHED;
98
99 return __pgprot(prot);
100 }
101
pte_none(pte_t pte)102 static inline int pte_none(pte_t pte)
103 {
104 return !(pte_val(pte) & ~(_PAGE_GLOBAL|0xf));
105 }
106
pte_present(pte_t pte)107 static inline int pte_present(pte_t pte) \
108 { return pte_val(pte) & _PAGE_PRESENT; }
109
110 /*
111 * The following only work if pte_present() is true.
112 * Undefined behaviour if not..
113 */
pte_wrprotect(pte_t pte)114 static inline pte_t pte_wrprotect(pte_t pte)
115 {
116 pte_val(pte) &= ~_PAGE_WRITE;
117 return pte;
118 }
119
pte_mkclean(pte_t pte)120 static inline pte_t pte_mkclean(pte_t pte)
121 {
122 pte_val(pte) &= ~_PAGE_DIRTY;
123 return pte;
124 }
125
pte_mkold(pte_t pte)126 static inline pte_t pte_mkold(pte_t pte)
127 {
128 pte_val(pte) &= ~_PAGE_ACCESSED;
129 return pte;
130 }
131
pte_mkwrite(pte_t pte)132 static inline pte_t pte_mkwrite(pte_t pte)
133 {
134 pte_val(pte) |= _PAGE_WRITE;
135 return pte;
136 }
137
pte_mkdirty(pte_t pte)138 static inline pte_t pte_mkdirty(pte_t pte)
139 {
140 pte_val(pte) |= _PAGE_DIRTY;
141 return pte;
142 }
143
pte_mkyoung(pte_t pte)144 static inline pte_t pte_mkyoung(pte_t pte)
145 {
146 pte_val(pte) |= _PAGE_ACCESSED;
147 return pte;
148 }
149
pte_modify(pte_t pte,pgprot_t newprot)150 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
151 {
152 const unsigned long mask = _PAGE_READ | _PAGE_WRITE | _PAGE_EXEC;
153
154 pte_val(pte) = (pte_val(pte) & ~mask) | (pgprot_val(newprot) & mask);
155 return pte;
156 }
157
pmd_present(pmd_t pmd)158 static inline int pmd_present(pmd_t pmd)
159 {
160 return (pmd_val(pmd) != (unsigned long) invalid_pte_table)
161 && (pmd_val(pmd) != 0UL);
162 }
163
pmd_clear(pmd_t * pmdp)164 static inline void pmd_clear(pmd_t *pmdp)
165 {
166 pmd_val(*pmdp) = (unsigned long) invalid_pte_table;
167 }
168
169 #define pte_pfn(pte) (pte_val(pte) & 0xfffff)
170 #define pfn_pte(pfn, prot) (__pte(pfn | pgprot_val(prot)))
171 #define pte_page(pte) (pfn_to_page(pte_pfn(pte)))
172
173 /*
174 * Store a linux PTE into the linux page table.
175 */
set_pte(pte_t * ptep,pte_t pteval)176 static inline void set_pte(pte_t *ptep, pte_t pteval)
177 {
178 *ptep = pteval;
179 }
180
set_pte_at(struct mm_struct * mm,unsigned long addr,pte_t * ptep,pte_t pteval)181 static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
182 pte_t *ptep, pte_t pteval)
183 {
184 unsigned long paddr = (unsigned long)page_to_virt(pte_page(pteval));
185
186 flush_dcache_range(paddr, paddr + PAGE_SIZE);
187 set_pte(ptep, pteval);
188 }
189
pmd_none(pmd_t pmd)190 static inline int pmd_none(pmd_t pmd)
191 {
192 return (pmd_val(pmd) ==
193 (unsigned long) invalid_pte_table) || (pmd_val(pmd) == 0UL);
194 }
195
196 #define pmd_bad(pmd) (pmd_val(pmd) & ~PAGE_MASK)
197
pte_clear(struct mm_struct * mm,unsigned long addr,pte_t * ptep)198 static inline void pte_clear(struct mm_struct *mm,
199 unsigned long addr, pte_t *ptep)
200 {
201 pte_t null;
202
203 pte_val(null) = (addr >> PAGE_SHIFT) & 0xf;
204
205 set_pte_at(mm, addr, ptep, null);
206 }
207
208 /*
209 * Conversion functions: convert a page and protection to a page entry,
210 * and a page entry and page directory to the page they refer to.
211 */
212 #define mk_pte(page, prot) (pfn_pte(page_to_pfn(page), prot))
213
214 /*
215 * Conversion functions: convert a page and protection to a page entry,
216 * and a page entry and page directory to the page they refer to.
217 */
218 #define pmd_phys(pmd) virt_to_phys((void *)pmd_val(pmd))
219 #define pmd_pfn(pmd) (pmd_phys(pmd) >> PAGE_SHIFT)
220 #define pmd_page(pmd) (pfn_to_page(pmd_phys(pmd) >> PAGE_SHIFT))
221
pmd_page_vaddr(pmd_t pmd)222 static inline unsigned long pmd_page_vaddr(pmd_t pmd)
223 {
224 return pmd_val(pmd);
225 }
226
227 #define pte_ERROR(e) \
228 pr_err("%s:%d: bad pte %08lx.\n", \
229 __FILE__, __LINE__, pte_val(e))
230 #define pgd_ERROR(e) \
231 pr_err("%s:%d: bad pgd %08lx.\n", \
232 __FILE__, __LINE__, pgd_val(e))
233
234 /*
235 * Encode and decode a swap entry (must be !pte_none(pte) && !pte_present(pte):
236 *
237 * 31 30 29 28 27 26 25 24 23 22 21 20 19 18 ... 1 0
238 * 0 0 0 0 type. 0 0 0 0 0 0 offset.........
239 *
240 * This gives us up to 2**2 = 4 swap files and 2**20 * 4K = 4G per swap file.
241 *
242 * Note that the offset field is always non-zero, thus !pte_none(pte) is always
243 * true.
244 */
245 #define __swp_type(swp) (((swp).val >> 26) & 0x3)
246 #define __swp_offset(swp) ((swp).val & 0xfffff)
247 #define __swp_entry(type, off) ((swp_entry_t) { (((type) & 0x3) << 26) \
248 | ((off) & 0xfffff) })
249 #define __swp_entry_to_pte(swp) ((pte_t) { (swp).val })
250 #define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) })
251
252 #define kern_addr_valid(addr) (1)
253
254 extern void __init paging_init(void);
255 extern void __init mmu_init(void);
256
257 extern void update_mmu_cache(struct vm_area_struct *vma,
258 unsigned long address, pte_t *pte);
259
260 #endif /* _ASM_NIOS2_PGTABLE_H */
261
