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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * CRIS pgtable.h - macros and functions to manipulate page tables.
3 */
4
5#ifndef _CRIS_PGTABLE_H
6#define _CRIS_PGTABLE_H
7
Mikael Starvik5d01e6c2005-07-27 11:44:43 -07008#include <asm/page.h>
9#include <asm-generic/pgtable-nopmd.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070010
11#ifndef __ASSEMBLY__
Linus Torvalds1da177e2005-04-16 15:20:36 -070012#include <linux/sched.h>
13#include <asm/mmu.h>
14#endif
15#include <asm/arch/pgtable.h>
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)
Mikael Starvik5d01e6c2005-07-27 11:44:43 -070044#define set_pgu(pudptr, pudval) (*(pudptr) = pudval)
Linus Torvalds1da177e2005-04-16 15:20:36 -070045
Mikael Starvik5d01e6c2005-07-27 11:44:43 -070046/* PGDIR_SHIFT determines the size of the area a second-level page table can
Linus Torvalds1da177e2005-04-16 15:20:36 -070047 * 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
Mikael Starvik5d01e6c2005-07-27 11:44:43 -070051#define PGDIR_SHIFT (PAGE_SHIFT + (PAGE_SHIFT-2))
Linus Torvalds1da177e2005-04-16 15:20:36 -070052#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))
Linus Torvalds1da177e2005-04-16 15:20:36 -070062#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)
Hugh Dickinsd455a362005-04-19 13:29:23 -070070#define FIRST_USER_ADDRESS 0
Linus Torvalds1da177e2005-04-16 15:20:36 -070071
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
Mikael Starvik5d01e6c2005-07-27 11:44:43 -070099#define pmd_none(x) (!pmd_val(x))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700100/* by removing the _PAGE_KERNEL bit from the comparision, the same pmd_bad
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
109/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700110 * The following only work if pte_present() is true.
111 * Undefined behaviour if not..
112 */
113
Adrian Bunkd9b54442005-11-07 00:58:44 -0800114static inline int pte_write(pte_t pte) { return pte_val(pte) & _PAGE_WRITE; }
Adrian Bunkd9b54442005-11-07 00:58:44 -0800115static 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; }
117static inline int pte_file(pte_t pte) { return pte_val(pte) & _PAGE_FILE; }
Nick Piggin7e675132008-04-28 02:13:00 -0700118static inline int pte_special(pte_t pte) { return 0; }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700119
Adrian Bunkd9b54442005-11-07 00:58:44 -0800120static inline pte_t pte_wrprotect(pte_t pte)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700121{
122 pte_val(pte) &= ~(_PAGE_WRITE | _PAGE_SILENT_WRITE);
123 return pte;
124}
125
Adrian Bunkd9b54442005-11-07 00:58:44 -0800126static inline pte_t pte_mkclean(pte_t pte)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700127{
128 pte_val(pte) &= ~(_PAGE_MODIFIED | _PAGE_SILENT_WRITE);
129 return pte;
130}
131
Adrian Bunkd9b54442005-11-07 00:58:44 -0800132static inline pte_t pte_mkold(pte_t pte)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700133{
134 pte_val(pte) &= ~(_PAGE_ACCESSED | _PAGE_SILENT_READ);
135 return pte;
136}
137
Adrian Bunkd9b54442005-11-07 00:58:44 -0800138static inline pte_t pte_mkwrite(pte_t pte)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700139{
140 pte_val(pte) |= _PAGE_WRITE;
141 if (pte_val(pte) & _PAGE_MODIFIED)
142 pte_val(pte) |= _PAGE_SILENT_WRITE;
143 return pte;
144}
145
Adrian Bunkd9b54442005-11-07 00:58:44 -0800146static inline pte_t pte_mkdirty(pte_t pte)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700147{
148 pte_val(pte) |= _PAGE_MODIFIED;
149 if (pte_val(pte) & _PAGE_WRITE)
150 pte_val(pte) |= _PAGE_SILENT_WRITE;
151 return pte;
152}
153
Adrian Bunkd9b54442005-11-07 00:58:44 -0800154static inline pte_t pte_mkyoung(pte_t pte)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155{
156 pte_val(pte) |= _PAGE_ACCESSED;
157 if (pte_val(pte) & _PAGE_READ)
158 {
159 pte_val(pte) |= _PAGE_SILENT_READ;
160 if ((pte_val(pte) & (_PAGE_WRITE | _PAGE_MODIFIED)) ==
161 (_PAGE_WRITE | _PAGE_MODIFIED))
162 pte_val(pte) |= _PAGE_SILENT_WRITE;
163 }
164 return pte;
165}
Nick Piggin7e675132008-04-28 02:13:00 -0700166static inline pte_t pte_mkspecial(pte_t pte) { return pte; }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700167
168/*
169 * Conversion functions: convert a page and protection to a page entry,
170 * and a page entry and page directory to the page they refer to.
171 */
172
173/* What actually goes as arguments to the various functions is less than
174 * obvious, but a rule of thumb is that struct page's goes as struct page *,
175 * really physical DRAM addresses are unsigned long's, and DRAM "virtual"
176 * addresses (the 0xc0xxxxxx's) goes as void *'s.
177 */
178
Adrian Bunkd9b54442005-11-07 00:58:44 -0800179static inline pte_t __mk_pte(void * page, pgprot_t pgprot)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700180{
181 pte_t pte;
182 /* the PTE needs a physical address */
183 pte_val(pte) = __pa(page) | pgprot_val(pgprot);
184 return pte;
185}
186
187#define mk_pte(page, pgprot) __mk_pte(page_address(page), (pgprot))
188
189#define mk_pte_phys(physpage, pgprot) \
190({ \
191 pte_t __pte; \
192 \
193 pte_val(__pte) = (physpage) + pgprot_val(pgprot); \
194 __pte; \
195})
196
Adrian Bunkd9b54442005-11-07 00:58:44 -0800197static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700198{ pte_val(pte) = (pte_val(pte) & _PAGE_CHG_MASK) | pgprot_val(newprot); return pte; }
199
200
201/* pte_val refers to a page in the 0x4xxxxxxx physical DRAM interval
202 * __pte_page(pte_val) refers to the "virtual" DRAM interval
203 * pte_pagenr refers to the page-number counted starting from the virtual DRAM start
204 */
205
Adrian Bunkd9b54442005-11-07 00:58:44 -0800206static inline unsigned long __pte_page(pte_t pte)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700207{
208 /* the PTE contains a physical address */
209 return (unsigned long)__va(pte_val(pte) & PAGE_MASK);
210}
211
212#define pte_pagenr(pte) ((__pte_page(pte) - PAGE_OFFSET) >> PAGE_SHIFT)
213
214/* permanent address of a page */
215
216#define __page_address(page) (PAGE_OFFSET + (((page) - mem_map) << PAGE_SHIFT))
217#define pte_page(pte) (mem_map+pte_pagenr(pte))
218
219/* only the pte's themselves need to point to physical DRAM (see above)
220 * the pagetable links are purely handled within the kernel SW and thus
221 * don't need the __pa and __va transformations.
222 */
223
Adrian Bunkd9b54442005-11-07 00:58:44 -0800224static inline void pmd_set(pmd_t * pmdp, pte_t * ptep)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700225{ pmd_val(*pmdp) = _PAGE_TABLE | (unsigned long) ptep; }
226
227#define pmd_page(pmd) (pfn_to_page(pmd_val(pmd) >> PAGE_SHIFT))
Dave McCracken46a82b22006-09-25 23:31:48 -0700228#define pmd_page_vaddr(pmd) ((unsigned long) __va(pmd_val(pmd) & PAGE_MASK))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700229
230/* to find an entry in a page-table-directory. */
Mikael Starvik5d01e6c2005-07-27 11:44:43 -0700231#define pgd_index(address) (((address) >> PGDIR_SHIFT) & (PTRS_PER_PGD-1))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700232
233/* to find an entry in a page-table-directory */
KOSAKI Motohiro16a26ef2008-04-28 02:13:51 -0700234static inline pgd_t * pgd_offset(const struct mm_struct *mm, unsigned long address)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700235{
236 return mm->pgd + pgd_index(address);
237}
238
239/* to find an entry in a kernel page-table-directory */
240#define pgd_offset_k(address) pgd_offset(&init_mm, address)
241
Linus Torvalds1da177e2005-04-16 15:20:36 -0700242/* Find an entry in the third-level page table.. */
243#define __pte_offset(address) \
244 (((address) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
245#define pte_offset_kernel(dir, address) \
Dave McCracken46a82b22006-09-25 23:31:48 -0700246 ((pte_t *) pmd_page_vaddr(*(dir)) + __pte_offset(address))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700247#define pte_offset_map(dir, address) \
248 ((pte_t *)page_address(pmd_page(*(dir))) + __pte_offset(address))
249#define pte_offset_map_nested(dir, address) pte_offset_map(dir, address)
250
251#define pte_unmap(pte) do { } while (0)
252#define pte_unmap_nested(pte) do { } while (0)
253#define pte_pfn(x) ((unsigned long)(__va((x).pte)) >> PAGE_SHIFT)
Jesper Nilsson620cf2e2008-01-21 15:49:43 +0100254#define pfn_pte(pfn, prot) __pte(((pfn) << PAGE_SHIFT) | pgprot_val(prot))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700255
256#define pte_ERROR(e) \
257 printk("%s:%d: bad pte %p(%08lx).\n", __FILE__, __LINE__, &(e), pte_val(e))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700258#define pgd_ERROR(e) \
259 printk("%s:%d: bad pgd %p(%08lx).\n", __FILE__, __LINE__, &(e), pgd_val(e))
260
261
262extern pgd_t swapper_pg_dir[PTRS_PER_PGD]; /* defined in head.S */
263
264/*
265 * CRIS doesn't have any external MMU info: the kernel page
266 * tables contain all the necessary information.
267 *
268 * Actually I am not sure on what this could be used for.
269 */
Adrian Bunkd9b54442005-11-07 00:58:44 -0800270static inline void update_mmu_cache(struct vm_area_struct * vma,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700271 unsigned long address, pte_t pte)
272{
273}
274
275/* Encode and de-code a swap entry (must be !pte_none(e) && !pte_present(e)) */
276/* Since the PAGE_PRESENT bit is bit 4, we can use the bits above */
277
278#define __swp_type(x) (((x).val >> 5) & 0x7f)
279#define __swp_offset(x) ((x).val >> 12)
280#define __swp_entry(type, offset) ((swp_entry_t) { ((type) << 5) | ((offset) << 12) })
281#define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) })
282#define __swp_entry_to_pte(x) ((pte_t) { (x).val })
283
284#define kern_addr_valid(addr) (1)
285
286#include <asm-generic/pgtable.h>
287
288/*
289 * No page table caches to initialise
290 */
291#define pgtable_cache_init() do { } while (0)
292
293#define pte_to_pgoff(x) (pte_val(x) >> 6)
294#define pgoff_to_pte(x) __pte(((x) << 6) | _PAGE_FILE)
295
Mikael Starvik5d01e6c2005-07-27 11:44:43 -0700296typedef pte_t *pte_addr_t;
297
Linus Torvalds1da177e2005-04-16 15:20:36 -0700298#endif /* __ASSEMBLY__ */
299#endif /* _CRIS_PGTABLE_H */