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 FIRST_USER_ADDRESS 0UL
28
29 #define VMALLOC_START CONFIG_NIOS2_KERNEL_MMU_REGION_BASE
30 #define VMALLOC_END (CONFIG_NIOS2_KERNEL_REGION_BASE - 1)
31
32 struct mm_struct;
33
34 /* Helper macro */
35 #define MKP(x, w, r) __pgprot(_PAGE_PRESENT | _PAGE_CACHED | \
36 ((x) ? _PAGE_EXEC : 0) | \
37 ((r) ? _PAGE_READ : 0) | \
38 ((w) ? _PAGE_WRITE : 0))
39 /*
40 * These are the macros that generic kernel code needs
41 * (to populate protection_map[])
42 */
43
44 /* Remove W bit on private pages for COW support */
45 #define __P000 MKP(0, 0, 0)
46 #define __P001 MKP(0, 0, 1)
47 #define __P010 MKP(0, 0, 0) /* COW */
48 #define __P011 MKP(0, 0, 1) /* COW */
49 #define __P100 MKP(1, 0, 0)
50 #define __P101 MKP(1, 0, 1)
51 #define __P110 MKP(1, 0, 0) /* COW */
52 #define __P111 MKP(1, 0, 1) /* COW */
53
54 /* Shared pages can have exact HW mapping */
55 #define __S000 MKP(0, 0, 0)
56 #define __S001 MKP(0, 0, 1)
57 #define __S010 MKP(0, 1, 0)
58 #define __S011 MKP(0, 1, 1)
59 #define __S100 MKP(1, 0, 0)
60 #define __S101 MKP(1, 0, 1)
61 #define __S110 MKP(1, 1, 0)
62 #define __S111 MKP(1, 1, 1)
63
64 /* Used all over the kernel */
65 #define PAGE_KERNEL __pgprot(_PAGE_PRESENT | _PAGE_CACHED | _PAGE_READ | \
66 _PAGE_WRITE | _PAGE_EXEC | _PAGE_GLOBAL)
67
68 #define PAGE_SHARED __pgprot(_PAGE_PRESENT | _PAGE_CACHED | _PAGE_READ | \
69 _PAGE_WRITE | _PAGE_ACCESSED)
70
71 #define PAGE_COPY MKP(0, 0, 1)
72
73 #define PGD_ORDER 0
74 #define PTE_ORDER 0
75
76 #define PTRS_PER_PGD ((PAGE_SIZE << PGD_ORDER) / sizeof(pgd_t))
77 #define PTRS_PER_PTE ((PAGE_SIZE << PTE_ORDER) / sizeof(pte_t))
78
79 #define USER_PTRS_PER_PGD \
80 (CONFIG_NIOS2_KERNEL_MMU_REGION_BASE / PGDIR_SIZE)
81
82 #define PGDIR_SHIFT 22
83 #define PGDIR_SIZE (1UL << PGDIR_SHIFT)
84 #define PGDIR_MASK (~(PGDIR_SIZE-1))
85
86 /*
87 * ZERO_PAGE is a global shared page that is always zero: used
88 * for zero-mapped memory areas etc..
89 */
90 extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)];
91 #define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page))
92
93 extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
94 extern pte_t invalid_pte_table[PAGE_SIZE/sizeof(pte_t)];
95
96 /*
97 * (pmds are folded into puds so this doesn't get actually called,
98 * but the define is needed for a generic inline function.)
99 */
set_pmd(pmd_t * pmdptr,pmd_t pmdval)100 static inline void set_pmd(pmd_t *pmdptr, pmd_t pmdval)
101 {
102 *pmdptr = pmdval;
103 }
104
pte_write(pte_t pte)105 static inline int pte_write(pte_t pte) \
106 { return pte_val(pte) & _PAGE_WRITE; }
pte_dirty(pte_t pte)107 static inline int pte_dirty(pte_t pte) \
108 { return pte_val(pte) & _PAGE_DIRTY; }
pte_young(pte_t pte)109 static inline int pte_young(pte_t pte) \
110 { return pte_val(pte) & _PAGE_ACCESSED; }
111
112 #define pgprot_noncached pgprot_noncached
113
pgprot_noncached(pgprot_t _prot)114 static inline pgprot_t pgprot_noncached(pgprot_t _prot)
115 {
116 unsigned long prot = pgprot_val(_prot);
117
118 prot &= ~_PAGE_CACHED;
119
120 return __pgprot(prot);
121 }
122
pte_none(pte_t pte)123 static inline int pte_none(pte_t pte)
124 {
125 return !(pte_val(pte) & ~(_PAGE_GLOBAL|0xf));
126 }
127
pte_present(pte_t pte)128 static inline int pte_present(pte_t pte) \
129 { return pte_val(pte) & _PAGE_PRESENT; }
130
131 /*
132 * The following only work if pte_present() is true.
133 * Undefined behaviour if not..
134 */
pte_wrprotect(pte_t pte)135 static inline pte_t pte_wrprotect(pte_t pte)
136 {
137 pte_val(pte) &= ~_PAGE_WRITE;
138 return pte;
139 }
140
pte_mkclean(pte_t pte)141 static inline pte_t pte_mkclean(pte_t pte)
142 {
143 pte_val(pte) &= ~_PAGE_DIRTY;
144 return pte;
145 }
146
pte_mkold(pte_t pte)147 static inline pte_t pte_mkold(pte_t pte)
148 {
149 pte_val(pte) &= ~_PAGE_ACCESSED;
150 return pte;
151 }
152
pte_mkwrite(pte_t pte)153 static inline pte_t pte_mkwrite(pte_t pte)
154 {
155 pte_val(pte) |= _PAGE_WRITE;
156 return pte;
157 }
158
pte_mkdirty(pte_t pte)159 static inline pte_t pte_mkdirty(pte_t pte)
160 {
161 pte_val(pte) |= _PAGE_DIRTY;
162 return pte;
163 }
164
pte_mkyoung(pte_t pte)165 static inline pte_t pte_mkyoung(pte_t pte)
166 {
167 pte_val(pte) |= _PAGE_ACCESSED;
168 return pte;
169 }
170
pte_modify(pte_t pte,pgprot_t newprot)171 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
172 {
173 const unsigned long mask = _PAGE_READ | _PAGE_WRITE | _PAGE_EXEC;
174
175 pte_val(pte) = (pte_val(pte) & ~mask) | (pgprot_val(newprot) & mask);
176 return pte;
177 }
178
pmd_present(pmd_t pmd)179 static inline int pmd_present(pmd_t pmd)
180 {
181 return (pmd_val(pmd) != (unsigned long) invalid_pte_table)
182 && (pmd_val(pmd) != 0UL);
183 }
184
pmd_clear(pmd_t * pmdp)185 static inline void pmd_clear(pmd_t *pmdp)
186 {
187 pmd_val(*pmdp) = (unsigned long) invalid_pte_table;
188 }
189
190 #define pte_pfn(pte) (pte_val(pte) & 0xfffff)
191 #define pfn_pte(pfn, prot) (__pte(pfn | pgprot_val(prot)))
192 #define pte_page(pte) (pfn_to_page(pte_pfn(pte)))
193
194 /*
195 * Store a linux PTE into the linux page table.
196 */
set_pte(pte_t * ptep,pte_t pteval)197 static inline void set_pte(pte_t *ptep, pte_t pteval)
198 {
199 *ptep = pteval;
200 }
201
set_pte_at(struct mm_struct * mm,unsigned long addr,pte_t * ptep,pte_t pteval)202 static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
203 pte_t *ptep, pte_t pteval)
204 {
205 unsigned long paddr = (unsigned long)page_to_virt(pte_page(pteval));
206
207 flush_dcache_range(paddr, paddr + PAGE_SIZE);
208 set_pte(ptep, pteval);
209 }
210
pmd_none(pmd_t pmd)211 static inline int pmd_none(pmd_t pmd)
212 {
213 return (pmd_val(pmd) ==
214 (unsigned long) invalid_pte_table) || (pmd_val(pmd) == 0UL);
215 }
216
217 #define pmd_bad(pmd) (pmd_val(pmd) & ~PAGE_MASK)
218
pte_clear(struct mm_struct * mm,unsigned long addr,pte_t * ptep)219 static inline void pte_clear(struct mm_struct *mm,
220 unsigned long addr, pte_t *ptep)
221 {
222 pte_t null;
223
224 pte_val(null) = (addr >> PAGE_SHIFT) & 0xf;
225
226 set_pte_at(mm, addr, ptep, null);
227 }
228
229 /*
230 * Conversion functions: convert a page and protection to a page entry,
231 * and a page entry and page directory to the page they refer to.
232 */
233 #define mk_pte(page, prot) (pfn_pte(page_to_pfn(page), prot))
234
235 /*
236 * Conversion functions: convert a page and protection to a page entry,
237 * and a page entry and page directory to the page they refer to.
238 */
239 #define pmd_phys(pmd) virt_to_phys((void *)pmd_val(pmd))
240 #define pmd_page(pmd) (pfn_to_page(pmd_phys(pmd) >> PAGE_SHIFT))
241
pmd_page_vaddr(pmd_t pmd)242 static inline unsigned long pmd_page_vaddr(pmd_t pmd)
243 {
244 return pmd_val(pmd);
245 }
246
247 #define pte_ERROR(e) \
248 pr_err("%s:%d: bad pte %08lx.\n", \
249 __FILE__, __LINE__, pte_val(e))
250 #define pgd_ERROR(e) \
251 pr_err("%s:%d: bad pgd %08lx.\n", \
252 __FILE__, __LINE__, pgd_val(e))
253
254 /*
255 * Encode and decode a swap entry (must be !pte_none(pte) && !pte_present(pte):
256 *
257 * 31 30 29 28 27 26 25 24 23 22 21 20 19 18 ... 1 0
258 * 0 0 0 0 type. 0 0 0 0 0 0 offset.........
259 *
260 * This gives us up to 2**2 = 4 swap files and 2**20 * 4K = 4G per swap file.
261 *
262 * Note that the offset field is always non-zero, thus !pte_none(pte) is always
263 * true.
264 */
265 #define __swp_type(swp) (((swp).val >> 26) & 0x3)
266 #define __swp_offset(swp) ((swp).val & 0xfffff)
267 #define __swp_entry(type, off) ((swp_entry_t) { (((type) & 0x3) << 26) \
268 | ((off) & 0xfffff) })
269 #define __swp_entry_to_pte(swp) ((pte_t) { (swp).val })
270 #define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) })
271
272 #define kern_addr_valid(addr) (1)
273
274 extern void __init paging_init(void);
275 extern void __init mmu_init(void);
276
277 extern void update_mmu_cache(struct vm_area_struct *vma,
278 unsigned long address, pte_t *pte);
279
280 #endif /* _ASM_NIOS2_PGTABLE_H */
281
