xref: /linux/arch/um/include/asm/pgtable.h (revision ebf68996de0ab250c5d520eb2291ab65643e9a1e)
1 /*
2  * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
3  * Copyright 2003 PathScale, Inc.
4  * Derived from include/asm-i386/pgtable.h
5  * Licensed under the GPL
6  */
7 
8 #ifndef __UM_PGTABLE_H
9 #define __UM_PGTABLE_H
10 
11 #include <asm/fixmap.h>
12 
13 #define _PAGE_PRESENT	0x001
14 #define _PAGE_NEWPAGE	0x002
15 #define _PAGE_NEWPROT	0x004
16 #define _PAGE_RW	0x020
17 #define _PAGE_USER	0x040
18 #define _PAGE_ACCESSED	0x080
19 #define _PAGE_DIRTY	0x100
20 /* If _PAGE_PRESENT is clear, we use these: */
21 #define _PAGE_PROTNONE	0x010	/* if the user mapped it with PROT_NONE;
22 				   pte_present gives true */
23 
24 #ifdef CONFIG_3_LEVEL_PGTABLES
25 #include <asm/pgtable-3level.h>
26 #else
27 #include <asm/pgtable-2level.h>
28 #endif
29 
30 extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
31 
32 /* zero page used for uninitialized stuff */
33 extern unsigned long *empty_zero_page;
34 
35 #define pgtable_cache_init() do ; while (0)
36 
37 /* Just any arbitrary offset to the start of the vmalloc VM area: the
38  * current 8MB value just means that there will be a 8MB "hole" after the
39  * physical memory until the kernel virtual memory starts.  That means that
40  * any out-of-bounds memory accesses will hopefully be caught.
41  * The vmalloc() routines leaves a hole of 4kB between each vmalloced
42  * area for the same reason. ;)
43  */
44 
45 extern unsigned long end_iomem;
46 
47 #define VMALLOC_OFFSET	(__va_space)
48 #define VMALLOC_START ((end_iomem + VMALLOC_OFFSET) & ~(VMALLOC_OFFSET-1))
49 #define PKMAP_BASE ((FIXADDR_START - LAST_PKMAP * PAGE_SIZE) & PMD_MASK)
50 #define VMALLOC_END	(FIXADDR_START-2*PAGE_SIZE)
51 #define MODULES_VADDR	VMALLOC_START
52 #define MODULES_END	VMALLOC_END
53 #define MODULES_LEN	(MODULES_VADDR - MODULES_END)
54 
55 #define _PAGE_TABLE	(_PAGE_PRESENT | _PAGE_RW | _PAGE_USER | _PAGE_ACCESSED | _PAGE_DIRTY)
56 #define _KERNPG_TABLE	(_PAGE_PRESENT | _PAGE_RW | _PAGE_ACCESSED | _PAGE_DIRTY)
57 #define _PAGE_CHG_MASK	(PAGE_MASK | _PAGE_ACCESSED | _PAGE_DIRTY)
58 #define __PAGE_KERNEL_EXEC                                              \
59 	 (_PAGE_PRESENT | _PAGE_RW | _PAGE_DIRTY | _PAGE_ACCESSED)
60 #define PAGE_NONE	__pgprot(_PAGE_PROTNONE | _PAGE_ACCESSED)
61 #define PAGE_SHARED	__pgprot(_PAGE_PRESENT | _PAGE_RW | _PAGE_USER | _PAGE_ACCESSED)
62 #define PAGE_COPY	__pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_ACCESSED)
63 #define PAGE_READONLY	__pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_ACCESSED)
64 #define PAGE_KERNEL	__pgprot(_PAGE_PRESENT | _PAGE_RW | _PAGE_DIRTY | _PAGE_ACCESSED)
65 #define PAGE_KERNEL_EXEC	__pgprot(__PAGE_KERNEL_EXEC)
66 
67 /*
68  * The i386 can't do page protection for execute, and considers that the same
69  * are read.
70  * Also, write permissions imply read permissions. This is the closest we can
71  * get..
72  */
73 #define __P000	PAGE_NONE
74 #define __P001	PAGE_READONLY
75 #define __P010	PAGE_COPY
76 #define __P011	PAGE_COPY
77 #define __P100	PAGE_READONLY
78 #define __P101	PAGE_READONLY
79 #define __P110	PAGE_COPY
80 #define __P111	PAGE_COPY
81 
82 #define __S000	PAGE_NONE
83 #define __S001	PAGE_READONLY
84 #define __S010	PAGE_SHARED
85 #define __S011	PAGE_SHARED
86 #define __S100	PAGE_READONLY
87 #define __S101	PAGE_READONLY
88 #define __S110	PAGE_SHARED
89 #define __S111	PAGE_SHARED
90 
91 /*
92  * ZERO_PAGE is a global shared page that is always zero: used
93  * for zero-mapped memory areas etc..
94  */
95 #define ZERO_PAGE(vaddr) virt_to_page(empty_zero_page)
96 
97 #define pte_clear(mm,addr,xp) pte_set_val(*(xp), (phys_t) 0, __pgprot(_PAGE_NEWPAGE))
98 
99 #define pmd_none(x)	(!((unsigned long)pmd_val(x) & ~_PAGE_NEWPAGE))
100 #define	pmd_bad(x)	((pmd_val(x) & (~PAGE_MASK & ~_PAGE_USER)) != _KERNPG_TABLE)
101 
102 #define pmd_present(x)	(pmd_val(x) & _PAGE_PRESENT)
103 #define pmd_clear(xp)	do { pmd_val(*(xp)) = _PAGE_NEWPAGE; } while (0)
104 
105 #define pmd_newpage(x)  (pmd_val(x) & _PAGE_NEWPAGE)
106 #define pmd_mkuptodate(x) (pmd_val(x) &= ~_PAGE_NEWPAGE)
107 
108 #define pud_newpage(x)  (pud_val(x) & _PAGE_NEWPAGE)
109 #define pud_mkuptodate(x) (pud_val(x) &= ~_PAGE_NEWPAGE)
110 
111 #define pmd_page(pmd) phys_to_page(pmd_val(pmd) & PAGE_MASK)
112 
113 #define pte_page(x) pfn_to_page(pte_pfn(x))
114 
115 #define pte_present(x)	pte_get_bits(x, (_PAGE_PRESENT | _PAGE_PROTNONE))
116 
117 /*
118  * =================================
119  * Flags checking section.
120  * =================================
121  */
122 
123 static inline int pte_none(pte_t pte)
124 {
125 	return pte_is_zero(pte);
126 }
127 
128 /*
129  * The following only work if pte_present() is true.
130  * Undefined behaviour if not..
131  */
132 static inline int pte_read(pte_t pte)
133 {
134 	return((pte_get_bits(pte, _PAGE_USER)) &&
135 	       !(pte_get_bits(pte, _PAGE_PROTNONE)));
136 }
137 
138 static inline int pte_exec(pte_t pte){
139 	return((pte_get_bits(pte, _PAGE_USER)) &&
140 	       !(pte_get_bits(pte, _PAGE_PROTNONE)));
141 }
142 
143 static inline int pte_write(pte_t pte)
144 {
145 	return((pte_get_bits(pte, _PAGE_RW)) &&
146 	       !(pte_get_bits(pte, _PAGE_PROTNONE)));
147 }
148 
149 static inline int pte_dirty(pte_t pte)
150 {
151 	return pte_get_bits(pte, _PAGE_DIRTY);
152 }
153 
154 static inline int pte_young(pte_t pte)
155 {
156 	return pte_get_bits(pte, _PAGE_ACCESSED);
157 }
158 
159 static inline int pte_newpage(pte_t pte)
160 {
161 	return pte_get_bits(pte, _PAGE_NEWPAGE);
162 }
163 
164 static inline int pte_newprot(pte_t pte)
165 {
166 	return(pte_present(pte) && (pte_get_bits(pte, _PAGE_NEWPROT)));
167 }
168 
169 static inline int pte_special(pte_t pte)
170 {
171 	return 0;
172 }
173 
174 /*
175  * =================================
176  * Flags setting section.
177  * =================================
178  */
179 
180 static inline pte_t pte_mknewprot(pte_t pte)
181 {
182 	pte_set_bits(pte, _PAGE_NEWPROT);
183 	return(pte);
184 }
185 
186 static inline pte_t pte_mkclean(pte_t pte)
187 {
188 	pte_clear_bits(pte, _PAGE_DIRTY);
189 	return(pte);
190 }
191 
192 static inline pte_t pte_mkold(pte_t pte)
193 {
194 	pte_clear_bits(pte, _PAGE_ACCESSED);
195 	return(pte);
196 }
197 
198 static inline pte_t pte_wrprotect(pte_t pte)
199 {
200 	if (likely(pte_get_bits(pte, _PAGE_RW)))
201 		pte_clear_bits(pte, _PAGE_RW);
202 	else
203 		return pte;
204 	return(pte_mknewprot(pte));
205 }
206 
207 static inline pte_t pte_mkread(pte_t pte)
208 {
209 	if (unlikely(pte_get_bits(pte, _PAGE_USER)))
210 		return pte;
211 	pte_set_bits(pte, _PAGE_USER);
212 	return(pte_mknewprot(pte));
213 }
214 
215 static inline pte_t pte_mkdirty(pte_t pte)
216 {
217 	pte_set_bits(pte, _PAGE_DIRTY);
218 	return(pte);
219 }
220 
221 static inline pte_t pte_mkyoung(pte_t pte)
222 {
223 	pte_set_bits(pte, _PAGE_ACCESSED);
224 	return(pte);
225 }
226 
227 static inline pte_t pte_mkwrite(pte_t pte)
228 {
229 	if (unlikely(pte_get_bits(pte,  _PAGE_RW)))
230 		return pte;
231 	pte_set_bits(pte, _PAGE_RW);
232 	return(pte_mknewprot(pte));
233 }
234 
235 static inline pte_t pte_mkuptodate(pte_t pte)
236 {
237 	pte_clear_bits(pte, _PAGE_NEWPAGE);
238 	if(pte_present(pte))
239 		pte_clear_bits(pte, _PAGE_NEWPROT);
240 	return(pte);
241 }
242 
243 static inline pte_t pte_mknewpage(pte_t pte)
244 {
245 	pte_set_bits(pte, _PAGE_NEWPAGE);
246 	return(pte);
247 }
248 
249 static inline pte_t pte_mkspecial(pte_t pte)
250 {
251 	return(pte);
252 }
253 
254 static inline void set_pte(pte_t *pteptr, pte_t pteval)
255 {
256 	pte_copy(*pteptr, pteval);
257 
258 	/* If it's a swap entry, it needs to be marked _PAGE_NEWPAGE so
259 	 * fix_range knows to unmap it.  _PAGE_NEWPROT is specific to
260 	 * mapped pages.
261 	 */
262 
263 	*pteptr = pte_mknewpage(*pteptr);
264 	if(pte_present(*pteptr)) *pteptr = pte_mknewprot(*pteptr);
265 }
266 
267 static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
268 			      pte_t *pteptr, pte_t pteval)
269 {
270 	set_pte(pteptr, pteval);
271 }
272 
273 #define __HAVE_ARCH_PTE_SAME
274 static inline int pte_same(pte_t pte_a, pte_t pte_b)
275 {
276 	return !((pte_val(pte_a) ^ pte_val(pte_b)) & ~_PAGE_NEWPAGE);
277 }
278 
279 /*
280  * Conversion functions: convert a page and protection to a page entry,
281  * and a page entry and page directory to the page they refer to.
282  */
283 
284 #define phys_to_page(phys) pfn_to_page(phys_to_pfn(phys))
285 #define __virt_to_page(virt) phys_to_page(__pa(virt))
286 #define page_to_phys(page) pfn_to_phys(page_to_pfn(page))
287 #define virt_to_page(addr) __virt_to_page((const unsigned long) addr)
288 
289 #define mk_pte(page, pgprot) \
290 	({ pte_t pte;					\
291 							\
292 	pte_set_val(pte, page_to_phys(page), (pgprot));	\
293 	if (pte_present(pte))				\
294 		pte_mknewprot(pte_mknewpage(pte));	\
295 	pte;})
296 
297 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
298 {
299 	pte_set_val(pte, (pte_val(pte) & _PAGE_CHG_MASK), newprot);
300 	return pte;
301 }
302 
303 /*
304  * the pgd page can be thought of an array like this: pgd_t[PTRS_PER_PGD]
305  *
306  * this macro returns the index of the entry in the pgd page which would
307  * control the given virtual address
308  */
309 #define pgd_index(address) (((address) >> PGDIR_SHIFT) & (PTRS_PER_PGD-1))
310 
311 /*
312  * pgd_offset() returns a (pgd_t *)
313  * pgd_index() is used get the offset into the pgd page's array of pgd_t's;
314  */
315 #define pgd_offset(mm, address) ((mm)->pgd+pgd_index(address))
316 
317 /*
318  * a shortcut which implies the use of the kernel's pgd, instead
319  * of a process's
320  */
321 #define pgd_offset_k(address) pgd_offset(&init_mm, address)
322 
323 /*
324  * the pmd page can be thought of an array like this: pmd_t[PTRS_PER_PMD]
325  *
326  * this macro returns the index of the entry in the pmd page which would
327  * control the given virtual address
328  */
329 #define pmd_page_vaddr(pmd) ((unsigned long) __va(pmd_val(pmd) & PAGE_MASK))
330 #define pmd_index(address) (((address) >> PMD_SHIFT) & (PTRS_PER_PMD-1))
331 
332 #define pmd_page_vaddr(pmd) \
333 	((unsigned long) __va(pmd_val(pmd) & PAGE_MASK))
334 
335 /*
336  * the pte page can be thought of an array like this: pte_t[PTRS_PER_PTE]
337  *
338  * this macro returns the index of the entry in the pte page which would
339  * control the given virtual address
340  */
341 #define pte_index(address) (((address) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
342 #define pte_offset_kernel(dir, address) \
343 	((pte_t *) pmd_page_vaddr(*(dir)) +  pte_index(address))
344 #define pte_offset_map(dir, address) \
345 	((pte_t *)page_address(pmd_page(*(dir))) + pte_index(address))
346 #define pte_unmap(pte) do { } while (0)
347 
348 struct mm_struct;
349 extern pte_t *virt_to_pte(struct mm_struct *mm, unsigned long addr);
350 
351 #define update_mmu_cache(vma,address,ptep) do ; while (0)
352 
353 /* Encode and de-code a swap entry */
354 #define __swp_type(x)			(((x).val >> 5) & 0x1f)
355 #define __swp_offset(x)			((x).val >> 11)
356 
357 #define __swp_entry(type, offset) \
358 	((swp_entry_t) { ((type) << 5) | ((offset) << 11) })
359 #define __pte_to_swp_entry(pte) \
360 	((swp_entry_t) { pte_val(pte_mkuptodate(pte)) })
361 #define __swp_entry_to_pte(x)		((pte_t) { (x).val })
362 
363 #define kern_addr_valid(addr) (1)
364 
365 #include <asm-generic/pgtable.h>
366 
367 /* Clear a kernel PTE and flush it from the TLB */
368 #define kpte_clear_flush(ptep, vaddr)		\
369 do {						\
370 	pte_clear(&init_mm, (vaddr), (ptep));	\
371 	__flush_tlb_one((vaddr));		\
372 } while (0)
373 
374 #endif
375