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1/*
2 * Copyright (C) 2011 Tobias Klauser <[email protected]>
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
33struct 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
68extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
69extern pte_t invalid_pte_table[PAGE_SIZE/sizeof(pte_t)];
70
71/*
72 * (pmds are folded into puds so this doesn't get actually called,
73 * but the define is needed for a generic inline function.)
74 */
75static inline void set_pmd(pmd_t *pmdptr, pmd_t pmdval)
76{
77 *pmdptr = pmdval;
78}
79
80static inline int pte_write(pte_t pte) \
81 { return pte_val(pte) & _PAGE_WRITE; }
82static inline int pte_dirty(pte_t pte) \
83 { return pte_val(pte) & _PAGE_DIRTY; }
84static inline int pte_young(pte_t pte) \
85 { return pte_val(pte) & _PAGE_ACCESSED; }
86
87#define pgprot_noncached pgprot_noncached
88
89static inline pgprot_t pgprot_noncached(pgprot_t _prot)
90{
91 unsigned long prot = pgprot_val(_prot);
92
93 prot &= ~_PAGE_CACHED;
94
95 return __pgprot(prot);
96}
97
98static inline int pte_none(pte_t pte)
99{
100 return !(pte_val(pte) & ~(_PAGE_GLOBAL|0xf));
101}
102
103static inline int pte_present(pte_t pte) \
104 { return pte_val(pte) & _PAGE_PRESENT; }
105
106/*
107 * The following only work if pte_present() is true.
108 * Undefined behaviour if not..
109 */
110static inline pte_t pte_wrprotect(pte_t pte)
111{
112 pte_val(pte) &= ~_PAGE_WRITE;
113 return pte;
114}
115
116static inline pte_t pte_mkclean(pte_t pte)
117{
118 pte_val(pte) &= ~_PAGE_DIRTY;
119 return pte;
120}
121
122static inline pte_t pte_mkold(pte_t pte)
123{
124 pte_val(pte) &= ~_PAGE_ACCESSED;
125 return pte;
126}
127
128static inline pte_t pte_mkwrite_novma(pte_t pte)
129{
130 pte_val(pte) |= _PAGE_WRITE;
131 return pte;
132}
133
134static inline pte_t pte_mkdirty(pte_t pte)
135{
136 pte_val(pte) |= _PAGE_DIRTY;
137 return pte;
138}
139
140static inline pte_t pte_mkyoung(pte_t pte)
141{
142 pte_val(pte) |= _PAGE_ACCESSED;
143 return pte;
144}
145
146static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
147{
148 const unsigned long mask = _PAGE_READ | _PAGE_WRITE | _PAGE_EXEC;
149
150 pte_val(pte) = (pte_val(pte) & ~mask) | (pgprot_val(newprot) & mask);
151 return pte;
152}
153
154static inline int pmd_present(pmd_t pmd)
155{
156 return (pmd_val(pmd) != (unsigned long) invalid_pte_table)
157 && (pmd_val(pmd) != 0UL);
158}
159
160static inline void pmd_clear(pmd_t *pmdp)
161{
162 pmd_val(*pmdp) = (unsigned long) invalid_pte_table;
163}
164
165#define pte_pfn(pte) (pte_val(pte) & 0xfffff)
166#define pfn_pte(pfn, prot) (__pte(pfn | pgprot_val(prot)))
167#define pte_page(pte) (pfn_to_page(pte_pfn(pte)))
168
169/*
170 * Store a linux PTE into the linux page table.
171 */
172static inline void set_pte(pte_t *ptep, pte_t pteval)
173{
174 *ptep = pteval;
175}
176
177#define PFN_PTE_SHIFT 0
178
179static inline void set_ptes(struct mm_struct *mm, unsigned long addr,
180 pte_t *ptep, pte_t pte, unsigned int nr)
181{
182 unsigned long paddr = (unsigned long)page_to_virt(pte_page(pte));
183
184 flush_dcache_range(paddr, paddr + nr * PAGE_SIZE);
185 for (;;) {
186 set_pte(ptep, pte);
187 if (--nr == 0)
188 break;
189 ptep++;
190 pte_val(pte) += 1;
191 }
192}
193#define set_ptes set_ptes
194
195static inline int pmd_none(pmd_t pmd)
196{
197 return (pmd_val(pmd) ==
198 (unsigned long) invalid_pte_table) || (pmd_val(pmd) == 0UL);
199}
200
201#define pmd_bad(pmd) (pmd_val(pmd) & ~PAGE_MASK)
202
203static inline void pte_clear(struct mm_struct *mm,
204 unsigned long addr, pte_t *ptep)
205{
206 pte_t null;
207
208 pte_val(null) = (addr >> PAGE_SHIFT) & 0xf;
209
210 set_pte(ptep, null);
211}
212
213/*
214 * Conversion functions: convert a page and protection to a page entry,
215 * and a page entry and page directory to the page they refer to.
216 */
217#define pmd_phys(pmd) virt_to_phys((void *)pmd_val(pmd))
218#define pmd_pfn(pmd) (pmd_phys(pmd) >> PAGE_SHIFT)
219#define pmd_page(pmd) (pfn_to_page(pmd_phys(pmd) >> PAGE_SHIFT))
220
221static inline unsigned long pmd_page_vaddr(pmd_t pmd)
222{
223 return pmd_val(pmd);
224}
225
226#define pte_ERROR(e) \
227 pr_err("%s:%d: bad pte %08lx.\n", \
228 __FILE__, __LINE__, pte_val(e))
229#define pgd_ERROR(e) \
230 pr_err("%s:%d: bad pgd %08lx.\n", \
231 __FILE__, __LINE__, pgd_val(e))
232
233/*
234 * Encode/decode swap entries and swap PTEs. Swap PTEs are all PTEs that
235 * are !pte_none() && !pte_present().
236 *
237 * Format of swap PTEs:
238 *
239 * 3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1
240 * 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
241 * E < type -> 0 0 0 0 0 0 <-------------- offset --------------->
242 *
243 * E is the exclusive marker that is not stored in swap entries.
244 *
245 * Note that the offset field is always non-zero if the swap type is 0, thus
246 * !pte_none() is always true.
247 */
248#define __swp_type(swp) (((swp).val >> 26) & 0x1f)
249#define __swp_offset(swp) ((swp).val & 0xfffff)
250#define __swp_entry(type, off) ((swp_entry_t) { (((type) & 0x1f) << 26) \
251 | ((off) & 0xfffff) })
252#define __swp_entry_to_pte(swp) ((pte_t) { (swp).val })
253#define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) })
254
255static inline bool pte_swp_exclusive(pte_t pte)
256{
257 return pte_val(pte) & _PAGE_SWP_EXCLUSIVE;
258}
259
260static inline pte_t pte_swp_mkexclusive(pte_t pte)
261{
262 pte_val(pte) |= _PAGE_SWP_EXCLUSIVE;
263 return pte;
264}
265
266static inline pte_t pte_swp_clear_exclusive(pte_t pte)
267{
268 pte_val(pte) &= ~_PAGE_SWP_EXCLUSIVE;
269 return pte;
270}
271
272extern void __init paging_init(void);
273extern void __init mmu_init(void);
274
275void update_mmu_cache_range(struct vm_fault *vmf, struct vm_area_struct *vma,
276 unsigned long address, pte_t *ptep, unsigned int nr);
277
278#define update_mmu_cache(vma, addr, ptep) \
279 update_mmu_cache_range(NULL, vma, addr, ptep, 1)
280
281static inline int pte_same(pte_t pte_a, pte_t pte_b);
282
283#define __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
284static inline int ptep_set_access_flags(struct vm_area_struct *vma,
285 unsigned long address, pte_t *ptep,
286 pte_t entry, int dirty)
287{
288 if (!pte_same(*ptep, entry))
289 set_ptes(vma->vm_mm, address, ptep, entry, 1);
290 /*
291 * update_mmu_cache will unconditionally execute, handling both
292 * the case that the PTE changed and the spurious fault case.
293 */
294 return true;
295}
296
297#endif /* _ASM_NIOS2_PGTABLE_H */