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 - SZ_32M - 1)
29
30 #define MODULES_VADDR (CONFIG_NIOS2_KERNEL_REGION_BASE - SZ_32M)
31 #define MODULES_END (CONFIG_NIOS2_KERNEL_REGION_BASE - 1)
32
33 struct mm_struct;
34
35 /* Helper macro */
36 #define MKP(x, w, r) __pgprot(_PAGE_PRESENT | _PAGE_CACHED | \
37 ((x) ? _PAGE_EXEC : 0) | \
38 ((r) ? _PAGE_READ : 0) | \
39 ((w) ? _PAGE_WRITE : 0))
40 /*
41 * These are the macros that generic kernel code needs
42 * (to populate protection_map[])
43 */
44
45 /* Remove W bit on private pages for COW support */
46
47 /* Shared pages can have exact HW mapping */
48
49 /* Used all over the kernel */
50 #define PAGE_KERNEL __pgprot(_PAGE_PRESENT | _PAGE_CACHED | _PAGE_READ | \
51 _PAGE_WRITE | _PAGE_EXEC | _PAGE_GLOBAL)
52
53 #define PAGE_SHARED __pgprot(_PAGE_PRESENT | _PAGE_CACHED | _PAGE_READ | \
54 _PAGE_WRITE | _PAGE_ACCESSED)
55
56 #define PAGE_COPY MKP(0, 0, 1)
57
58 #define PTRS_PER_PGD (PAGE_SIZE / sizeof(pgd_t))
59 #define PTRS_PER_PTE (PAGE_SIZE / sizeof(pte_t))
60
61 #define USER_PTRS_PER_PGD \
62 (CONFIG_NIOS2_KERNEL_MMU_REGION_BASE / PGDIR_SIZE)
63
64 #define PGDIR_SHIFT 22
65 #define PGDIR_SIZE (1UL << PGDIR_SHIFT)
66 #define PGDIR_MASK (~(PGDIR_SIZE-1))
67
68 /*
69 * ZERO_PAGE is a global shared page that is always zero: used
70 * for zero-mapped memory areas etc..
71 */
72 extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)];
73 #define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page))
74
75 extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
76 extern pte_t invalid_pte_table[PAGE_SIZE/sizeof(pte_t)];
77
78 /*
79 * (pmds are folded into puds so this doesn't get actually called,
80 * but the define is needed for a generic inline function.)
81 */
82 static inline void set_pmd(pmd_t *pmdptr, pmd_t pmdval)
83 {
84 *pmdptr = pmdval;
85 }
86
87 static inline int pte_write(pte_t pte) \
88 { return pte_val(pte) & _PAGE_WRITE; }
89 static inline int pte_dirty(pte_t pte) \
90 { return pte_val(pte) & _PAGE_DIRTY; }
91 static inline int pte_young(pte_t pte) \
92 { return pte_val(pte) & _PAGE_ACCESSED; }
93
94 #define pgprot_noncached pgprot_noncached
95
96 static inline pgprot_t pgprot_noncached(pgprot_t _prot)
97 {
98 unsigned long prot = pgprot_val(_prot);
99
100 prot &= ~_PAGE_CACHED;
101
102 return __pgprot(prot);
103 }
104
105 static inline int pte_none(pte_t pte)
106 {
107 return !(pte_val(pte) & ~(_PAGE_GLOBAL|0xf));
108 }
109
110 static inline int pte_present(pte_t pte) \
111 { return pte_val(pte) & _PAGE_PRESENT; }
112
113 /*
114 * The following only work if pte_present() is true.
115 * Undefined behaviour if not..
116 */
117 static inline pte_t pte_wrprotect(pte_t pte)
118 {
119 pte_val(pte) &= ~_PAGE_WRITE;
120 return pte;
121 }
122
123 static inline pte_t pte_mkclean(pte_t pte)
124 {
125 pte_val(pte) &= ~_PAGE_DIRTY;
126 return pte;
127 }
128
129 static inline pte_t pte_mkold(pte_t pte)
130 {
131 pte_val(pte) &= ~_PAGE_ACCESSED;
132 return pte;
133 }
134
135 static inline pte_t pte_mkwrite_novma(pte_t pte)
136 {
137 pte_val(pte) |= _PAGE_WRITE;
138 return pte;
139 }
140
141 static inline pte_t pte_mkdirty(pte_t pte)
142 {
143 pte_val(pte) |= _PAGE_DIRTY;
144 return pte;
145 }
146
147 static inline pte_t pte_mkyoung(pte_t pte)
148 {
149 pte_val(pte) |= _PAGE_ACCESSED;
150 return pte;
151 }
152
153 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
154 {
155 const unsigned long mask = _PAGE_READ | _PAGE_WRITE | _PAGE_EXEC;
156
157 pte_val(pte) = (pte_val(pte) & ~mask) | (pgprot_val(newprot) & mask);
158 return pte;
159 }
160
161 static inline int pmd_present(pmd_t pmd)
162 {
163 return (pmd_val(pmd) != (unsigned long) invalid_pte_table)
164 && (pmd_val(pmd) != 0UL);
165 }
166
167 static inline void pmd_clear(pmd_t *pmdp)
168 {
169 pmd_val(*pmdp) = (unsigned long) invalid_pte_table;
170 }
171
172 #define pte_pfn(pte) (pte_val(pte) & 0xfffff)
173 #define pfn_pte(pfn, prot) (__pte(pfn | pgprot_val(prot)))
174 #define pte_page(pte) (pfn_to_page(pte_pfn(pte)))
175
176 /*
177 * Store a linux PTE into the linux page table.
178 */
179 static inline void set_pte(pte_t *ptep, pte_t pteval)
180 {
181 *ptep = pteval;
182 }
183
184 #define PFN_PTE_SHIFT 0
185
186 static inline void set_ptes(struct mm_struct *mm, unsigned long addr,
187 pte_t *ptep, pte_t pte, unsigned int nr)
188 {
189 unsigned long paddr = (unsigned long)page_to_virt(pte_page(pte));
190
191 flush_dcache_range(paddr, paddr + nr * PAGE_SIZE);
192 for (;;) {
193 set_pte(ptep, pte);
194 if (--nr == 0)
195 break;
196 ptep++;
197 pte_val(pte) += 1;
198 }
199 }
200 #define set_ptes set_ptes
201
202 static inline int pmd_none(pmd_t pmd)
203 {
204 return (pmd_val(pmd) ==
205 (unsigned long) invalid_pte_table) || (pmd_val(pmd) == 0UL);
206 }
207
208 #define pmd_bad(pmd) (pmd_val(pmd) & ~PAGE_MASK)
209
210 static inline void pte_clear(struct mm_struct *mm,
211 unsigned long addr, pte_t *ptep)
212 {
213 pte_t null;
214
215 pte_val(null) = (addr >> PAGE_SHIFT) & 0xf;
216
217 set_pte(ptep, null);
218 }
219
220 /*
221 * Conversion functions: convert a page and protection to a page entry,
222 * and a page entry and page directory to the page they refer to.
223 */
224 #define mk_pte(page, prot) (pfn_pte(page_to_pfn(page), prot))
225
226 /*
227 * Conversion functions: convert a page and protection to a page entry,
228 * and a page entry and page directory to the page they refer to.
229 */
230 #define pmd_phys(pmd) virt_to_phys((void *)pmd_val(pmd))
231 #define pmd_pfn(pmd) (pmd_phys(pmd) >> PAGE_SHIFT)
232 #define pmd_page(pmd) (pfn_to_page(pmd_phys(pmd) >> PAGE_SHIFT))
233
234 static inline unsigned long pmd_page_vaddr(pmd_t pmd)
235 {
236 return pmd_val(pmd);
237 }
238
239 #define pte_ERROR(e) \
240 pr_err("%s:%d: bad pte %08lx.\n", \
241 __FILE__, __LINE__, pte_val(e))
242 #define pgd_ERROR(e) \
243 pr_err("%s:%d: bad pgd %08lx.\n", \
244 __FILE__, __LINE__, pgd_val(e))
245
246 /*
247 * Encode/decode swap entries and swap PTEs. Swap PTEs are all PTEs that
248 * are !pte_none() && !pte_present().
249 *
250 * Format of swap PTEs:
251 *
252 * 3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1
253 * 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0
254 * E < type -> 0 0 0 0 0 0 <-------------- offset --------------->
255 *
256 * E is the exclusive marker that is not stored in swap entries.
257 *
258 * Note that the offset field is always non-zero if the swap type is 0, thus
259 * !pte_none() is always true.
260 */
261 #define __swp_type(swp) (((swp).val >> 26) & 0x1f)
262 #define __swp_offset(swp) ((swp).val & 0xfffff)
263 #define __swp_entry(type, off) ((swp_entry_t) { (((type) & 0x1f) << 26) \
264 | ((off) & 0xfffff) })
265 #define __swp_entry_to_pte(swp) ((pte_t) { (swp).val })
266 #define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) })
267
268 static inline int pte_swp_exclusive(pte_t pte)
269 {
270 return pte_val(pte) & _PAGE_SWP_EXCLUSIVE;
271 }
272
273 static inline pte_t pte_swp_mkexclusive(pte_t pte)
274 {
275 pte_val(pte) |= _PAGE_SWP_EXCLUSIVE;
276 return pte;
277 }
278
279 static inline pte_t pte_swp_clear_exclusive(pte_t pte)
280 {
281 pte_val(pte) &= ~_PAGE_SWP_EXCLUSIVE;
282 return pte;
283 }
284
285 extern void __init paging_init(void);
286 extern void __init mmu_init(void);
287
288 void update_mmu_cache_range(struct vm_fault *vmf, struct vm_area_struct *vma,
289 unsigned long address, pte_t *ptep, unsigned int nr);
290
291 #define update_mmu_cache(vma, addr, ptep) \
292 update_mmu_cache_range(NULL, vma, addr, ptep, 1)
293
294 #endif /* _ASM_NIOS2_PGTABLE_H */
295
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