xref: /openbmc/linux/arch/um/include/asm/pgtable.h (revision d9e32672)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
4  * Copyright 2003 PathScale, Inc.
5  * Derived from include/asm-i386/pgtable.h
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 /* Just any arbitrary offset to the start of the vmalloc VM area: the
36  * current 8MB value just means that there will be a 8MB "hole" after the
37  * physical memory until the kernel virtual memory starts.  That means that
38  * any out-of-bounds memory accesses will hopefully be caught.
39  * The vmalloc() routines leaves a hole of 4kB between each vmalloced
40  * area for the same reason. ;)
41  */
42 
43 extern unsigned long end_iomem;
44 
45 #define VMALLOC_OFFSET	(__va_space)
46 #define VMALLOC_START ((end_iomem + VMALLOC_OFFSET) & ~(VMALLOC_OFFSET-1))
47 #define PKMAP_BASE ((FIXADDR_START - LAST_PKMAP * PAGE_SIZE) & PMD_MASK)
48 #define VMALLOC_END	(FIXADDR_START-2*PAGE_SIZE)
49 #define MODULES_VADDR	VMALLOC_START
50 #define MODULES_END	VMALLOC_END
51 #define MODULES_LEN	(MODULES_VADDR - MODULES_END)
52 
53 #define _PAGE_TABLE	(_PAGE_PRESENT | _PAGE_RW | _PAGE_USER | _PAGE_ACCESSED | _PAGE_DIRTY)
54 #define _KERNPG_TABLE	(_PAGE_PRESENT | _PAGE_RW | _PAGE_ACCESSED | _PAGE_DIRTY)
55 #define _PAGE_CHG_MASK	(PAGE_MASK | _PAGE_ACCESSED | _PAGE_DIRTY)
56 #define __PAGE_KERNEL_EXEC                                              \
57 	 (_PAGE_PRESENT | _PAGE_RW | _PAGE_DIRTY | _PAGE_ACCESSED)
58 #define PAGE_NONE	__pgprot(_PAGE_PROTNONE | _PAGE_ACCESSED)
59 #define PAGE_SHARED	__pgprot(_PAGE_PRESENT | _PAGE_RW | _PAGE_USER | _PAGE_ACCESSED)
60 #define PAGE_COPY	__pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_ACCESSED)
61 #define PAGE_READONLY	__pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_ACCESSED)
62 #define PAGE_KERNEL	__pgprot(_PAGE_PRESENT | _PAGE_RW | _PAGE_DIRTY | _PAGE_ACCESSED)
63 #define PAGE_KERNEL_EXEC	__pgprot(__PAGE_KERNEL_EXEC)
64 
65 /*
66  * The i386 can't do page protection for execute, and considers that the same
67  * are read.
68  * Also, write permissions imply read permissions. This is the closest we can
69  * get..
70  */
71 #define __P000	PAGE_NONE
72 #define __P001	PAGE_READONLY
73 #define __P010	PAGE_COPY
74 #define __P011	PAGE_COPY
75 #define __P100	PAGE_READONLY
76 #define __P101	PAGE_READONLY
77 #define __P110	PAGE_COPY
78 #define __P111	PAGE_COPY
79 
80 #define __S000	PAGE_NONE
81 #define __S001	PAGE_READONLY
82 #define __S010	PAGE_SHARED
83 #define __S011	PAGE_SHARED
84 #define __S100	PAGE_READONLY
85 #define __S101	PAGE_READONLY
86 #define __S110	PAGE_SHARED
87 #define __S111	PAGE_SHARED
88 
89 /*
90  * ZERO_PAGE is a global shared page that is always zero: used
91  * for zero-mapped memory areas etc..
92  */
93 #define ZERO_PAGE(vaddr) virt_to_page(empty_zero_page)
94 
95 #define pte_clear(mm,addr,xp) pte_set_val(*(xp), (phys_t) 0, __pgprot(_PAGE_NEWPAGE))
96 
97 #define pmd_none(x)	(!((unsigned long)pmd_val(x) & ~_PAGE_NEWPAGE))
98 #define	pmd_bad(x)	((pmd_val(x) & (~PAGE_MASK & ~_PAGE_USER)) != _KERNPG_TABLE)
99 
100 #define pmd_present(x)	(pmd_val(x) & _PAGE_PRESENT)
101 #define pmd_clear(xp)	do { pmd_val(*(xp)) = _PAGE_NEWPAGE; } while (0)
102 
103 #define pmd_newpage(x)  (pmd_val(x) & _PAGE_NEWPAGE)
104 #define pmd_mkuptodate(x) (pmd_val(x) &= ~_PAGE_NEWPAGE)
105 
106 #define pud_newpage(x)  (pud_val(x) & _PAGE_NEWPAGE)
107 #define pud_mkuptodate(x) (pud_val(x) &= ~_PAGE_NEWPAGE)
108 
109 #define pmd_page(pmd) phys_to_page(pmd_val(pmd) & PAGE_MASK)
110 
111 #define pte_page(x) pfn_to_page(pte_pfn(x))
112 
113 #define pte_present(x)	pte_get_bits(x, (_PAGE_PRESENT | _PAGE_PROTNONE))
114 
115 /*
116  * =================================
117  * Flags checking section.
118  * =================================
119  */
120 
121 static inline int pte_none(pte_t pte)
122 {
123 	return pte_is_zero(pte);
124 }
125 
126 /*
127  * The following only work if pte_present() is true.
128  * Undefined behaviour if not..
129  */
130 static inline int pte_read(pte_t pte)
131 {
132 	return((pte_get_bits(pte, _PAGE_USER)) &&
133 	       !(pte_get_bits(pte, _PAGE_PROTNONE)));
134 }
135 
136 static inline int pte_exec(pte_t pte){
137 	return((pte_get_bits(pte, _PAGE_USER)) &&
138 	       !(pte_get_bits(pte, _PAGE_PROTNONE)));
139 }
140 
141 static inline int pte_write(pte_t pte)
142 {
143 	return((pte_get_bits(pte, _PAGE_RW)) &&
144 	       !(pte_get_bits(pte, _PAGE_PROTNONE)));
145 }
146 
147 static inline int pte_dirty(pte_t pte)
148 {
149 	return pte_get_bits(pte, _PAGE_DIRTY);
150 }
151 
152 static inline int pte_young(pte_t pte)
153 {
154 	return pte_get_bits(pte, _PAGE_ACCESSED);
155 }
156 
157 static inline int pte_newpage(pte_t pte)
158 {
159 	return pte_get_bits(pte, _PAGE_NEWPAGE);
160 }
161 
162 static inline int pte_newprot(pte_t pte)
163 {
164 	return(pte_present(pte) && (pte_get_bits(pte, _PAGE_NEWPROT)));
165 }
166 
167 static inline int pte_special(pte_t pte)
168 {
169 	return 0;
170 }
171 
172 /*
173  * =================================
174  * Flags setting section.
175  * =================================
176  */
177 
178 static inline pte_t pte_mknewprot(pte_t pte)
179 {
180 	pte_set_bits(pte, _PAGE_NEWPROT);
181 	return(pte);
182 }
183 
184 static inline pte_t pte_mkclean(pte_t pte)
185 {
186 	pte_clear_bits(pte, _PAGE_DIRTY);
187 	return(pte);
188 }
189 
190 static inline pte_t pte_mkold(pte_t pte)
191 {
192 	pte_clear_bits(pte, _PAGE_ACCESSED);
193 	return(pte);
194 }
195 
196 static inline pte_t pte_wrprotect(pte_t pte)
197 {
198 	if (likely(pte_get_bits(pte, _PAGE_RW)))
199 		pte_clear_bits(pte, _PAGE_RW);
200 	else
201 		return pte;
202 	return(pte_mknewprot(pte));
203 }
204 
205 static inline pte_t pte_mkread(pte_t pte)
206 {
207 	if (unlikely(pte_get_bits(pte, _PAGE_USER)))
208 		return pte;
209 	pte_set_bits(pte, _PAGE_USER);
210 	return(pte_mknewprot(pte));
211 }
212 
213 static inline pte_t pte_mkdirty(pte_t pte)
214 {
215 	pte_set_bits(pte, _PAGE_DIRTY);
216 	return(pte);
217 }
218 
219 static inline pte_t pte_mkyoung(pte_t pte)
220 {
221 	pte_set_bits(pte, _PAGE_ACCESSED);
222 	return(pte);
223 }
224 
225 static inline pte_t pte_mkwrite(pte_t pte)
226 {
227 	if (unlikely(pte_get_bits(pte,  _PAGE_RW)))
228 		return pte;
229 	pte_set_bits(pte, _PAGE_RW);
230 	return(pte_mknewprot(pte));
231 }
232 
233 static inline pte_t pte_mkuptodate(pte_t pte)
234 {
235 	pte_clear_bits(pte, _PAGE_NEWPAGE);
236 	if(pte_present(pte))
237 		pte_clear_bits(pte, _PAGE_NEWPROT);
238 	return(pte);
239 }
240 
241 static inline pte_t pte_mknewpage(pte_t pte)
242 {
243 	pte_set_bits(pte, _PAGE_NEWPAGE);
244 	return(pte);
245 }
246 
247 static inline pte_t pte_mkspecial(pte_t pte)
248 {
249 	return(pte);
250 }
251 
252 static inline void set_pte(pte_t *pteptr, pte_t pteval)
253 {
254 	pte_copy(*pteptr, pteval);
255 
256 	/* If it's a swap entry, it needs to be marked _PAGE_NEWPAGE so
257 	 * fix_range knows to unmap it.  _PAGE_NEWPROT is specific to
258 	 * mapped pages.
259 	 */
260 
261 	*pteptr = pte_mknewpage(*pteptr);
262 	if(pte_present(*pteptr)) *pteptr = pte_mknewprot(*pteptr);
263 }
264 
265 static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
266 			      pte_t *pteptr, pte_t pteval)
267 {
268 	set_pte(pteptr, pteval);
269 }
270 
271 #define __HAVE_ARCH_PTE_SAME
272 static inline int pte_same(pte_t pte_a, pte_t pte_b)
273 {
274 	return !((pte_val(pte_a) ^ pte_val(pte_b)) & ~_PAGE_NEWPAGE);
275 }
276 
277 /*
278  * Conversion functions: convert a page and protection to a page entry,
279  * and a page entry and page directory to the page they refer to.
280  */
281 
282 #define phys_to_page(phys) pfn_to_page(phys_to_pfn(phys))
283 #define __virt_to_page(virt) phys_to_page(__pa(virt))
284 #define page_to_phys(page) pfn_to_phys(page_to_pfn(page))
285 #define virt_to_page(addr) __virt_to_page((const unsigned long) addr)
286 
287 #define mk_pte(page, pgprot) \
288 	({ pte_t pte;					\
289 							\
290 	pte_set_val(pte, page_to_phys(page), (pgprot));	\
291 	if (pte_present(pte))				\
292 		pte_mknewprot(pte_mknewpage(pte));	\
293 	pte;})
294 
295 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
296 {
297 	pte_set_val(pte, (pte_val(pte) & _PAGE_CHG_MASK), newprot);
298 	return pte;
299 }
300 
301 /*
302  * the pgd page can be thought of an array like this: pgd_t[PTRS_PER_PGD]
303  *
304  * this macro returns the index of the entry in the pgd page which would
305  * control the given virtual address
306  */
307 #define pgd_index(address) (((address) >> PGDIR_SHIFT) & (PTRS_PER_PGD-1))
308 
309 /*
310  * pgd_offset() returns a (pgd_t *)
311  * pgd_index() is used get the offset into the pgd page's array of pgd_t's;
312  */
313 #define pgd_offset(mm, address) ((mm)->pgd+pgd_index(address))
314 
315 /*
316  * a shortcut which implies the use of the kernel's pgd, instead
317  * of a process's
318  */
319 #define pgd_offset_k(address) pgd_offset(&init_mm, address)
320 
321 /*
322  * the pmd page can be thought of an array like this: pmd_t[PTRS_PER_PMD]
323  *
324  * this macro returns the index of the entry in the pmd page which would
325  * control the given virtual address
326  */
327 #define pmd_page_vaddr(pmd) ((unsigned long) __va(pmd_val(pmd) & PAGE_MASK))
328 #define pmd_index(address) (((address) >> PMD_SHIFT) & (PTRS_PER_PMD-1))
329 
330 #define pmd_page_vaddr(pmd) \
331 	((unsigned long) __va(pmd_val(pmd) & PAGE_MASK))
332 
333 /*
334  * the pte page can be thought of an array like this: pte_t[PTRS_PER_PTE]
335  *
336  * this macro returns the index of the entry in the pte page which would
337  * control the given virtual address
338  */
339 #define pte_index(address) (((address) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
340 #define pte_offset_kernel(dir, address) \
341 	((pte_t *) pmd_page_vaddr(*(dir)) +  pte_index(address))
342 #define pte_offset_map(dir, address) \
343 	((pte_t *)page_address(pmd_page(*(dir))) + pte_index(address))
344 #define pte_unmap(pte) do { } while (0)
345 
346 struct mm_struct;
347 extern pte_t *virt_to_pte(struct mm_struct *mm, unsigned long addr);
348 
349 #define update_mmu_cache(vma,address,ptep) do ; while (0)
350 
351 /* Encode and de-code a swap entry */
352 #define __swp_type(x)			(((x).val >> 5) & 0x1f)
353 #define __swp_offset(x)			((x).val >> 11)
354 
355 #define __swp_entry(type, offset) \
356 	((swp_entry_t) { ((type) << 5) | ((offset) << 11) })
357 #define __pte_to_swp_entry(pte) \
358 	((swp_entry_t) { pte_val(pte_mkuptodate(pte)) })
359 #define __swp_entry_to_pte(x)		((pte_t) { (x).val })
360 
361 #define kern_addr_valid(addr) (1)
362 
363 #include <asm-generic/pgtable.h>
364 
365 /* Clear a kernel PTE and flush it from the TLB */
366 #define kpte_clear_flush(ptep, vaddr)		\
367 do {						\
368 	pte_clear(&init_mm, (vaddr), (ptep));	\
369 	__flush_tlb_one((vaddr));		\
370 } while (0)
371 
372 #endif
373