Linux kernel mirror (for testing)
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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#define __ARCH_USE_5LEVEL_HACK
26#include <asm-generic/pgtable-nopmd.h>
27
28#define FIRST_USER_ADDRESS 0UL
29
30#define VMALLOC_START CONFIG_NIOS2_KERNEL_MMU_REGION_BASE
31#define VMALLOC_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#define __P000 MKP(0, 0, 0)
47#define __P001 MKP(0, 0, 1)
48#define __P010 MKP(0, 0, 0) /* COW */
49#define __P011 MKP(0, 0, 1) /* COW */
50#define __P100 MKP(1, 0, 0)
51#define __P101 MKP(1, 0, 1)
52#define __P110 MKP(1, 0, 0) /* COW */
53#define __P111 MKP(1, 0, 1) /* COW */
54
55/* Shared pages can have exact HW mapping */
56#define __S000 MKP(0, 0, 0)
57#define __S001 MKP(0, 0, 1)
58#define __S010 MKP(0, 1, 0)
59#define __S011 MKP(0, 1, 1)
60#define __S100 MKP(1, 0, 0)
61#define __S101 MKP(1, 0, 1)
62#define __S110 MKP(1, 1, 0)
63#define __S111 MKP(1, 1, 1)
64
65/* Used all over the kernel */
66#define PAGE_KERNEL __pgprot(_PAGE_PRESENT | _PAGE_CACHED | _PAGE_READ | \
67 _PAGE_WRITE | _PAGE_EXEC | _PAGE_GLOBAL)
68
69#define PAGE_SHARED __pgprot(_PAGE_PRESENT | _PAGE_CACHED | _PAGE_READ | \
70 _PAGE_WRITE | _PAGE_ACCESSED)
71
72#define PAGE_COPY MKP(0, 0, 1)
73
74#define PGD_ORDER 0
75#define PTE_ORDER 0
76
77#define PTRS_PER_PGD ((PAGE_SIZE << PGD_ORDER) / sizeof(pgd_t))
78#define PTRS_PER_PTE ((PAGE_SIZE << PTE_ORDER) / sizeof(pte_t))
79
80#define USER_PTRS_PER_PGD \
81 (CONFIG_NIOS2_KERNEL_MMU_REGION_BASE / PGDIR_SIZE)
82
83#define PGDIR_SHIFT 22
84#define PGDIR_SIZE (1UL << PGDIR_SHIFT)
85#define PGDIR_MASK (~(PGDIR_SIZE-1))
86
87/*
88 * ZERO_PAGE is a global shared page that is always zero: used
89 * for zero-mapped memory areas etc..
90 */
91extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)];
92#define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page))
93
94extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
95extern pte_t invalid_pte_table[PAGE_SIZE/sizeof(pte_t)];
96
97/*
98 * (pmds are folded into puds so this doesn't get actually called,
99 * but the define is needed for a generic inline function.)
100 */
101static inline void set_pmd(pmd_t *pmdptr, pmd_t pmdval)
102{
103 pmdptr->pud.pgd.pgd = pmdval.pud.pgd.pgd;
104}
105
106/* to find an entry in a page-table-directory */
107#define pgd_index(addr) (((addr) >> PGDIR_SHIFT) & (PTRS_PER_PGD - 1))
108#define pgd_offset(mm, addr) ((mm)->pgd + pgd_index(addr))
109
110static inline int pte_write(pte_t pte) \
111 { return pte_val(pte) & _PAGE_WRITE; }
112static inline int pte_dirty(pte_t pte) \
113 { return pte_val(pte) & _PAGE_DIRTY; }
114static inline int pte_young(pte_t pte) \
115 { return pte_val(pte) & _PAGE_ACCESSED; }
116static inline int pte_special(pte_t pte) { return 0; }
117
118#define pgprot_noncached pgprot_noncached
119
120static inline pgprot_t pgprot_noncached(pgprot_t _prot)
121{
122 unsigned long prot = pgprot_val(_prot);
123
124 prot &= ~_PAGE_CACHED;
125
126 return __pgprot(prot);
127}
128
129static inline int pte_none(pte_t pte)
130{
131 return !(pte_val(pte) & ~(_PAGE_GLOBAL|0xf));
132}
133
134static inline int pte_present(pte_t pte) \
135 { return pte_val(pte) & _PAGE_PRESENT; }
136
137/*
138 * The following only work if pte_present() is true.
139 * Undefined behaviour if not..
140 */
141static inline pte_t pte_wrprotect(pte_t pte)
142{
143 pte_val(pte) &= ~_PAGE_WRITE;
144 return pte;
145}
146
147static inline pte_t pte_mkclean(pte_t pte)
148{
149 pte_val(pte) &= ~_PAGE_DIRTY;
150 return pte;
151}
152
153static inline pte_t pte_mkold(pte_t pte)
154{
155 pte_val(pte) &= ~_PAGE_ACCESSED;
156 return pte;
157}
158
159static inline pte_t pte_mkwrite(pte_t pte)
160{
161 pte_val(pte) |= _PAGE_WRITE;
162 return pte;
163}
164
165static inline pte_t pte_mkdirty(pte_t pte)
166{
167 pte_val(pte) |= _PAGE_DIRTY;
168 return pte;
169}
170
171static inline pte_t pte_mkspecial(pte_t pte) { return pte; }
172
173static inline pte_t pte_mkyoung(pte_t pte)
174{
175 pte_val(pte) |= _PAGE_ACCESSED;
176 return pte;
177}
178
179static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
180{
181 const unsigned long mask = _PAGE_READ | _PAGE_WRITE | _PAGE_EXEC;
182
183 pte_val(pte) = (pte_val(pte) & ~mask) | (pgprot_val(newprot) & mask);
184 return pte;
185}
186
187static inline int pmd_present(pmd_t pmd)
188{
189 return (pmd_val(pmd) != (unsigned long) invalid_pte_table)
190 && (pmd_val(pmd) != 0UL);
191}
192
193static inline void pmd_clear(pmd_t *pmdp)
194{
195 pmd_val(*pmdp) = (unsigned long) invalid_pte_table;
196}
197
198#define pte_pfn(pte) (pte_val(pte) & 0xfffff)
199#define pfn_pte(pfn, prot) (__pte(pfn | pgprot_val(prot)))
200#define pte_page(pte) (pfn_to_page(pte_pfn(pte)))
201
202/*
203 * Store a linux PTE into the linux page table.
204 */
205static inline void set_pte(pte_t *ptep, pte_t pteval)
206{
207 *ptep = pteval;
208}
209
210static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
211 pte_t *ptep, pte_t pteval)
212{
213 unsigned long paddr = (unsigned long)page_to_virt(pte_page(pteval));
214
215 flush_dcache_range(paddr, paddr + PAGE_SIZE);
216 set_pte(ptep, pteval);
217}
218
219static inline int pmd_none(pmd_t pmd)
220{
221 return (pmd_val(pmd) ==
222 (unsigned long) invalid_pte_table) || (pmd_val(pmd) == 0UL);
223}
224
225#define pmd_bad(pmd) (pmd_val(pmd) & ~PAGE_MASK)
226
227static inline void pte_clear(struct mm_struct *mm,
228 unsigned long addr, pte_t *ptep)
229{
230 pte_t null;
231
232 pte_val(null) = (addr >> PAGE_SHIFT) & 0xf;
233
234 set_pte_at(mm, addr, ptep, null);
235}
236
237/*
238 * Conversion functions: convert a page and protection to a page entry,
239 * and a page entry and page directory to the page they refer to.
240 */
241#define mk_pte(page, prot) (pfn_pte(page_to_pfn(page), prot))
242
243#define pte_unmap(pte) do { } while (0)
244
245/*
246 * Conversion functions: convert a page and protection to a page entry,
247 * and a page entry and page directory to the page they refer to.
248 */
249#define pmd_phys(pmd) virt_to_phys((void *)pmd_val(pmd))
250#define pmd_page(pmd) (pfn_to_page(pmd_phys(pmd) >> PAGE_SHIFT))
251#define pmd_page_vaddr(pmd) pmd_val(pmd)
252
253#define pte_offset_map(dir, addr) \
254 ((pte_t *) page_address(pmd_page(*dir)) + \
255 (((addr) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1)))
256
257/* to find an entry in a kernel page-table-directory */
258#define pgd_offset_k(addr) pgd_offset(&init_mm, addr)
259
260/* Get the address to the PTE for a vaddr in specific directory */
261#define pte_offset_kernel(dir, addr) \
262 ((pte_t *) pmd_page_vaddr(*(dir)) + \
263 (((addr) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1)))
264
265#define pte_ERROR(e) \
266 pr_err("%s:%d: bad pte %08lx.\n", \
267 __FILE__, __LINE__, pte_val(e))
268#define pgd_ERROR(e) \
269 pr_err("%s:%d: bad pgd %08lx.\n", \
270 __FILE__, __LINE__, pgd_val(e))
271
272/*
273 * Encode and decode a swap entry (must be !pte_none(pte) && !pte_present(pte):
274 *
275 * 31 30 29 28 27 26 25 24 23 22 21 20 19 18 ... 1 0
276 * 0 0 0 0 type. 0 0 0 0 0 0 offset.........
277 *
278 * This gives us up to 2**2 = 4 swap files and 2**20 * 4K = 4G per swap file.
279 *
280 * Note that the offset field is always non-zero, thus !pte_none(pte) is always
281 * true.
282 */
283#define __swp_type(swp) (((swp).val >> 26) & 0x3)
284#define __swp_offset(swp) ((swp).val & 0xfffff)
285#define __swp_entry(type, off) ((swp_entry_t) { (((type) & 0x3) << 26) \
286 | ((off) & 0xfffff) })
287#define __swp_entry_to_pte(swp) ((pte_t) { (swp).val })
288#define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) })
289
290#define kern_addr_valid(addr) (1)
291
292#include <asm-generic/pgtable.h>
293
294extern void __init paging_init(void);
295extern void __init mmu_init(void);
296
297extern void update_mmu_cache(struct vm_area_struct *vma,
298 unsigned long address, pte_t *pte);
299
300#endif /* _ASM_NIOS2_PGTABLE_H */