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
30struct 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 */
69extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)];
70#define ZERO_PAGE(vaddr)	(virt_to_page(empty_zero_page))
71
72extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
73extern 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 */
79static inline void set_pmd(pmd_t *pmdptr, pmd_t pmdval)
80{
81	*pmdptr = pmdval;
82}
83
84static inline int pte_write(pte_t pte)		\
85	{ return pte_val(pte) & _PAGE_WRITE; }
86static inline int pte_dirty(pte_t pte)		\
87	{ return pte_val(pte) & _PAGE_DIRTY; }
88static inline int pte_young(pte_t pte)		\
89	{ return pte_val(pte) & _PAGE_ACCESSED; }
90
91#define pgprot_noncached pgprot_noncached
92
93static 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
102static inline int pte_none(pte_t pte)
103{
104	return !(pte_val(pte) & ~(_PAGE_GLOBAL|0xf));
105}
106
107static 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 */
114static inline pte_t pte_wrprotect(pte_t pte)
115{
116	pte_val(pte) &= ~_PAGE_WRITE;
117	return pte;
118}
119
120static inline pte_t pte_mkclean(pte_t pte)
121{
122	pte_val(pte) &= ~_PAGE_DIRTY;
123	return pte;
124}
125
126static inline pte_t pte_mkold(pte_t pte)
127{
128	pte_val(pte) &= ~_PAGE_ACCESSED;
129	return pte;
130}
131
132static inline pte_t pte_mkwrite_novma(pte_t pte)
133{
134	pte_val(pte) |= _PAGE_WRITE;
135	return pte;
136}
137
138static inline pte_t pte_mkdirty(pte_t pte)
139{
140	pte_val(pte) |= _PAGE_DIRTY;
141	return pte;
142}
143
144static inline pte_t pte_mkyoung(pte_t pte)
145{
146	pte_val(pte) |= _PAGE_ACCESSED;
147	return pte;
148}
149
150static 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
158static 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
164static 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 */
176static inline void set_pte(pte_t *ptep, pte_t pteval)
177{
178	*ptep = pteval;
179}
180
181#define PFN_PTE_SHIFT		0
182
183static inline void set_ptes(struct mm_struct *mm, unsigned long addr,
184		pte_t *ptep, pte_t pte, unsigned int nr)
185{
186	unsigned long paddr = (unsigned long)page_to_virt(pte_page(pte));
187
188	flush_dcache_range(paddr, paddr + nr * PAGE_SIZE);
189	for (;;) {
190		set_pte(ptep, pte);
191		if (--nr == 0)
192			break;
193		ptep++;
194		pte_val(pte) += 1;
195	}
196}
197#define set_ptes set_ptes
198
199static inline int pmd_none(pmd_t pmd)
200{
201	return (pmd_val(pmd) ==
202		(unsigned long) invalid_pte_table) || (pmd_val(pmd) == 0UL);
203}
204
205#define pmd_bad(pmd)	(pmd_val(pmd) & ~PAGE_MASK)
206
207static inline void pte_clear(struct mm_struct *mm,
208				unsigned long addr, pte_t *ptep)
209{
210	pte_t null;
211
212	pte_val(null) = (addr >> PAGE_SHIFT) & 0xf;
213
214	set_pte(ptep, null);
215}
216
217/*
218 * Conversion functions: convert a page and protection to a page entry,
219 * and a page entry and page directory to the page they refer to.
220 */
221#define mk_pte(page, prot)	(pfn_pte(page_to_pfn(page), prot))
222
223/*
224 * Conversion functions: convert a page and protection to a page entry,
225 * and a page entry and page directory to the page they refer to.
226 */
227#define pmd_phys(pmd)		virt_to_phys((void *)pmd_val(pmd))
228#define pmd_pfn(pmd)		(pmd_phys(pmd) >> PAGE_SHIFT)
229#define pmd_page(pmd)		(pfn_to_page(pmd_phys(pmd) >> PAGE_SHIFT))
230
231static inline unsigned long pmd_page_vaddr(pmd_t pmd)
232{
233	return pmd_val(pmd);
234}
235
236#define pte_ERROR(e) \
237	pr_err("%s:%d: bad pte %08lx.\n", \
238		__FILE__, __LINE__, pte_val(e))
239#define pgd_ERROR(e) \
240	pr_err("%s:%d: bad pgd %08lx.\n", \
241		__FILE__, __LINE__, pgd_val(e))
242
243/*
244 * Encode/decode swap entries and swap PTEs. Swap PTEs are all PTEs that
245 * are !pte_none() && !pte_present().
246 *
247 * Format of swap PTEs:
248 *
249 *   3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1
250 *   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
251 *   E < type -> 0 0 0 0 0 0 <-------------- offset --------------->
252 *
253 *   E is the exclusive marker that is not stored in swap entries.
254 *
255 * Note that the offset field is always non-zero if the swap type is 0, thus
256 * !pte_none() is always true.
257 */
258#define __swp_type(swp)		(((swp).val >> 26) & 0x1f)
259#define __swp_offset(swp)	((swp).val & 0xfffff)
260#define __swp_entry(type, off)	((swp_entry_t) { (((type) & 0x1f) << 26) \
261						 | ((off) & 0xfffff) })
262#define __swp_entry_to_pte(swp)	((pte_t) { (swp).val })
263#define __pte_to_swp_entry(pte)	((swp_entry_t) { pte_val(pte) })
264
265static inline int pte_swp_exclusive(pte_t pte)
266{
267	return pte_val(pte) & _PAGE_SWP_EXCLUSIVE;
268}
269
270static inline pte_t pte_swp_mkexclusive(pte_t pte)
271{
272	pte_val(pte) |= _PAGE_SWP_EXCLUSIVE;
273	return pte;
274}
275
276static inline pte_t pte_swp_clear_exclusive(pte_t pte)
277{
278	pte_val(pte) &= ~_PAGE_SWP_EXCLUSIVE;
279	return pte;
280}
281
282extern void __init paging_init(void);
283extern void __init mmu_init(void);
284
285void update_mmu_cache_range(struct vm_fault *vmf, struct vm_area_struct *vma,
286		unsigned long address, pte_t *ptep, unsigned int nr);
287
288#define update_mmu_cache(vma, addr, ptep) \
289	update_mmu_cache_range(NULL, vma, addr, ptep, 1)
290
291#endif /* _ASM_NIOS2_PGTABLE_H */
292