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1/*
2 * CRIS pgtable.h - macros and functions to manipulate page tables.
3 */
4
5#ifndef _CRIS_PGTABLE_H
6#define _CRIS_PGTABLE_H
7
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8#include <asm/page.h>
9#include <asm-generic/pgtable-nopmd.h>
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10
11#ifndef __ASSEMBLY__
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12#include <linux/sched.h>
13#include <asm/mmu.h>
14#endif
556dcee7 15#include <arch/pgtable.h>
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16
17/*
18 * The Linux memory management assumes a three-level page table setup. On
19 * CRIS, we use that, but "fold" the mid level into the top-level page
20 * table. Since the MMU TLB is software loaded through an interrupt, it
21 * supports any page table structure, so we could have used a three-level
22 * setup, but for the amounts of memory we normally use, a two-level is
23 * probably more efficient.
24 *
25 * This file contains the functions and defines necessary to modify and use
26 * the CRIS page table tree.
27 */
28#ifndef __ASSEMBLY__
29extern void paging_init(void);
30#endif
31
32/* Certain architectures need to do special things when pte's
33 * within a page table are directly modified. Thus, the following
34 * hook is made available.
35 */
36#define set_pte(pteptr, pteval) ((*(pteptr)) = (pteval))
37#define set_pte_at(mm,addr,ptep,pteval) set_pte(ptep,pteval)
38
39/*
40 * (pmds are folded into pgds so this doesn't get actually called,
41 * but the define is needed for a generic inline function.)
42 */
43#define set_pmd(pmdptr, pmdval) (*(pmdptr) = pmdval)
5d01e6ce 44#define set_pgu(pudptr, pudval) (*(pudptr) = pudval)
1da177e4 45
5d01e6ce 46/* PGDIR_SHIFT determines the size of the area a second-level page table can
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47 * map. It is equal to the page size times the number of PTE's that fit in
48 * a PMD page. A PTE is 4-bytes in CRIS. Hence the following number.
49 */
50
5d01e6ce 51#define PGDIR_SHIFT (PAGE_SHIFT + (PAGE_SHIFT-2))
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52#define PGDIR_SIZE (1UL << PGDIR_SHIFT)
53#define PGDIR_MASK (~(PGDIR_SIZE-1))
54
55/*
56 * entries per page directory level: we use a two-level, so
57 * we don't really have any PMD directory physically.
58 * pointers are 4 bytes so we can use the page size and
59 * divide it by 4 (shift by 2).
60 */
61#define PTRS_PER_PTE (1UL << (PAGE_SHIFT-2))
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62#define PTRS_PER_PGD (1UL << (PAGE_SHIFT-2))
63
64/* calculate how many PGD entries a user-level program can use
65 * the first mappable virtual address is 0
66 * (TASK_SIZE is the maximum virtual address space)
67 */
68
69#define USER_PTRS_PER_PGD (TASK_SIZE/PGDIR_SIZE)
d016bf7e 70#define FIRST_USER_ADDRESS 0UL
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71
72/* zero page used for uninitialized stuff */
73#ifndef __ASSEMBLY__
74extern unsigned long empty_zero_page;
75#define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page))
76#endif
77
78/* number of bits that fit into a memory pointer */
79#define BITS_PER_PTR (8*sizeof(unsigned long))
80
81/* to align the pointer to a pointer address */
82#define PTR_MASK (~(sizeof(void*)-1))
83
84/* sizeof(void*)==1<<SIZEOF_PTR_LOG2 */
85/* 64-bit machines, beware! SRB. */
86#define SIZEOF_PTR_LOG2 2
87
88/* to find an entry in a page-table */
89#define PAGE_PTR(address) \
90((unsigned long)(address)>>(PAGE_SHIFT-SIZEOF_PTR_LOG2)&PTR_MASK&~PAGE_MASK)
91
92/* to set the page-dir */
93#define SET_PAGE_DIR(tsk,pgdir)
94
95#define pte_none(x) (!pte_val(x))
96#define pte_present(x) (pte_val(x) & _PAGE_PRESENT)
97#define pte_clear(mm,addr,xp) do { pte_val(*(xp)) = 0; } while (0)
98
5d01e6ce 99#define pmd_none(x) (!pmd_val(x))
25985edc 100/* by removing the _PAGE_KERNEL bit from the comparison, the same pmd_bad
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101 * works for both _PAGE_TABLE and _KERNPG_TABLE pmd entries.
102 */
103#define pmd_bad(x) ((pmd_val(x) & (~PAGE_MASK & ~_PAGE_KERNEL)) != _PAGE_TABLE)
104#define pmd_present(x) (pmd_val(x) & _PAGE_PRESENT)
105#define pmd_clear(xp) do { pmd_val(*(xp)) = 0; } while (0)
106
107#ifndef __ASSEMBLY__
108
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109/*
110 * The following only work if pte_present() is true.
111 * Undefined behaviour if not..
112 */
113
d9b5444e 114static inline int pte_write(pte_t pte) { return pte_val(pte) & _PAGE_WRITE; }
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115static inline int pte_dirty(pte_t pte) { return pte_val(pte) & _PAGE_MODIFIED; }
116static inline int pte_young(pte_t pte) { return pte_val(pte) & _PAGE_ACCESSED; }
7e675137 117static inline int pte_special(pte_t pte) { return 0; }
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118
119static inline pte_t pte_wrprotect(pte_t pte)
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120{
121 pte_val(pte) &= ~(_PAGE_WRITE | _PAGE_SILENT_WRITE);
122 return pte;
123}
124
d9b5444e 125static inline pte_t pte_mkclean(pte_t pte)
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126{
127 pte_val(pte) &= ~(_PAGE_MODIFIED | _PAGE_SILENT_WRITE);
128 return pte;
129}
130
d9b5444e 131static inline pte_t pte_mkold(pte_t pte)
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132{
133 pte_val(pte) &= ~(_PAGE_ACCESSED | _PAGE_SILENT_READ);
134 return pte;
135}
136
d9b5444e 137static inline pte_t pte_mkwrite(pte_t pte)
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138{
139 pte_val(pte) |= _PAGE_WRITE;
140 if (pte_val(pte) & _PAGE_MODIFIED)
141 pte_val(pte) |= _PAGE_SILENT_WRITE;
142 return pte;
143}
144
d9b5444e 145static inline pte_t pte_mkdirty(pte_t pte)
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146{
147 pte_val(pte) |= _PAGE_MODIFIED;
148 if (pte_val(pte) & _PAGE_WRITE)
149 pte_val(pte) |= _PAGE_SILENT_WRITE;
150 return pte;
151}
152
d9b5444e 153static inline pte_t pte_mkyoung(pte_t pte)
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154{
155 pte_val(pte) |= _PAGE_ACCESSED;
156 if (pte_val(pte) & _PAGE_READ)
157 {
158 pte_val(pte) |= _PAGE_SILENT_READ;
159 if ((pte_val(pte) & (_PAGE_WRITE | _PAGE_MODIFIED)) ==
160 (_PAGE_WRITE | _PAGE_MODIFIED))
161 pte_val(pte) |= _PAGE_SILENT_WRITE;
162 }
163 return pte;
164}
7e675137 165static inline pte_t pte_mkspecial(pte_t pte) { return pte; }
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166
167/*
168 * Conversion functions: convert a page and protection to a page entry,
169 * and a page entry and page directory to the page they refer to.
170 */
171
172/* What actually goes as arguments to the various functions is less than
173 * obvious, but a rule of thumb is that struct page's goes as struct page *,
174 * really physical DRAM addresses are unsigned long's, and DRAM "virtual"
175 * addresses (the 0xc0xxxxxx's) goes as void *'s.
176 */
177
d9b5444e 178static inline pte_t __mk_pte(void * page, pgprot_t pgprot)
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179{
180 pte_t pte;
181 /* the PTE needs a physical address */
182 pte_val(pte) = __pa(page) | pgprot_val(pgprot);
183 return pte;
184}
185
186#define mk_pte(page, pgprot) __mk_pte(page_address(page), (pgprot))
187
188#define mk_pte_phys(physpage, pgprot) \
189({ \
190 pte_t __pte; \
191 \
192 pte_val(__pte) = (physpage) + pgprot_val(pgprot); \
193 __pte; \
194})
195
d9b5444e 196static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
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197{ pte_val(pte) = (pte_val(pte) & _PAGE_CHG_MASK) | pgprot_val(newprot); return pte; }
198
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199#define pgprot_noncached(prot) __pgprot((pgprot_val(prot) | _PAGE_NO_CACHE))
200
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201
202/* pte_val refers to a page in the 0x4xxxxxxx physical DRAM interval
203 * __pte_page(pte_val) refers to the "virtual" DRAM interval
204 * pte_pagenr refers to the page-number counted starting from the virtual DRAM start
205 */
206
d9b5444e 207static inline unsigned long __pte_page(pte_t pte)
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208{
209 /* the PTE contains a physical address */
210 return (unsigned long)__va(pte_val(pte) & PAGE_MASK);
211}
212
213#define pte_pagenr(pte) ((__pte_page(pte) - PAGE_OFFSET) >> PAGE_SHIFT)
214
215/* permanent address of a page */
216
217#define __page_address(page) (PAGE_OFFSET + (((page) - mem_map) << PAGE_SHIFT))
218#define pte_page(pte) (mem_map+pte_pagenr(pte))
219
220/* only the pte's themselves need to point to physical DRAM (see above)
221 * the pagetable links are purely handled within the kernel SW and thus
222 * don't need the __pa and __va transformations.
223 */
224
d9b5444e 225static inline void pmd_set(pmd_t * pmdp, pte_t * ptep)
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226{ pmd_val(*pmdp) = _PAGE_TABLE | (unsigned long) ptep; }
227
228#define pmd_page(pmd) (pfn_to_page(pmd_val(pmd) >> PAGE_SHIFT))
46a82b2d 229#define pmd_page_vaddr(pmd) ((unsigned long) __va(pmd_val(pmd) & PAGE_MASK))
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230
231/* to find an entry in a page-table-directory. */
5d01e6ce 232#define pgd_index(address) (((address) >> PGDIR_SHIFT) & (PTRS_PER_PGD-1))
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233
234/* to find an entry in a page-table-directory */
16a26ef5 235static inline pgd_t * pgd_offset(const struct mm_struct *mm, unsigned long address)
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236{
237 return mm->pgd + pgd_index(address);
238}
239
240/* to find an entry in a kernel page-table-directory */
241#define pgd_offset_k(address) pgd_offset(&init_mm, address)
242
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243/* Find an entry in the third-level page table.. */
244#define __pte_offset(address) \
245 (((address) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
246#define pte_offset_kernel(dir, address) \
46a82b2d 247 ((pte_t *) pmd_page_vaddr(*(dir)) + __pte_offset(address))
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248#define pte_offset_map(dir, address) \
249 ((pte_t *)page_address(pmd_page(*(dir))) + __pte_offset(address))
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250
251#define pte_unmap(pte) do { } while (0)
1da177e4 252#define pte_pfn(x) ((unsigned long)(__va((x).pte)) >> PAGE_SHIFT)
620cf2e4 253#define pfn_pte(pfn, prot) __pte(((pfn) << PAGE_SHIFT) | pgprot_val(prot))
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254
255#define pte_ERROR(e) \
256 printk("%s:%d: bad pte %p(%08lx).\n", __FILE__, __LINE__, &(e), pte_val(e))
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257#define pgd_ERROR(e) \
258 printk("%s:%d: bad pgd %p(%08lx).\n", __FILE__, __LINE__, &(e), pgd_val(e))
259
260
261extern pgd_t swapper_pg_dir[PTRS_PER_PGD]; /* defined in head.S */
262
263/*
264 * CRIS doesn't have any external MMU info: the kernel page
265 * tables contain all the necessary information.
266 *
267 * Actually I am not sure on what this could be used for.
268 */
d9b5444e 269static inline void update_mmu_cache(struct vm_area_struct * vma,
4b3073e1 270 unsigned long address, pte_t *ptep)
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271{
272}
273
274/* Encode and de-code a swap entry (must be !pte_none(e) && !pte_present(e)) */
275/* Since the PAGE_PRESENT bit is bit 4, we can use the bits above */
276
277#define __swp_type(x) (((x).val >> 5) & 0x7f)
278#define __swp_offset(x) ((x).val >> 12)
279#define __swp_entry(type, offset) ((swp_entry_t) { ((type) << 5) | ((offset) << 12) })
280#define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) })
281#define __swp_entry_to_pte(x) ((pte_t) { (x).val })
282
283#define kern_addr_valid(addr) (1)
284
285#include <asm-generic/pgtable.h>
286
287/*
288 * No page table caches to initialise
289 */
290#define pgtable_cache_init() do { } while (0)
291
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292typedef pte_t *pte_addr_t;
293
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294#endif /* __ASSEMBLY__ */
295#endif /* _CRIS_PGTABLE_H */