xref: /openbmc/linux/arch/um/include/asm/pgtable.h (revision dc6a81c3)
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 p4d_newpage(x)  (p4d_val(x) & _PAGE_NEWPAGE)
110 #define p4d_mkuptodate(x) (p4d_val(x) &= ~_PAGE_NEWPAGE)
111 
112 #define pmd_page(pmd) phys_to_page(pmd_val(pmd) & PAGE_MASK)
113 
114 #define pte_page(x) pfn_to_page(pte_pfn(x))
115 
116 #define pte_present(x)	pte_get_bits(x, (_PAGE_PRESENT | _PAGE_PROTNONE))
117 
118 /*
119  * =================================
120  * Flags checking section.
121  * =================================
122  */
123 
124 static inline int pte_none(pte_t pte)
125 {
126 	return pte_is_zero(pte);
127 }
128 
129 /*
130  * The following only work if pte_present() is true.
131  * Undefined behaviour if not..
132  */
133 static inline int pte_read(pte_t pte)
134 {
135 	return((pte_get_bits(pte, _PAGE_USER)) &&
136 	       !(pte_get_bits(pte, _PAGE_PROTNONE)));
137 }
138 
139 static inline int pte_exec(pte_t pte){
140 	return((pte_get_bits(pte, _PAGE_USER)) &&
141 	       !(pte_get_bits(pte, _PAGE_PROTNONE)));
142 }
143 
144 static inline int pte_write(pte_t pte)
145 {
146 	return((pte_get_bits(pte, _PAGE_RW)) &&
147 	       !(pte_get_bits(pte, _PAGE_PROTNONE)));
148 }
149 
150 static inline int pte_dirty(pte_t pte)
151 {
152 	return pte_get_bits(pte, _PAGE_DIRTY);
153 }
154 
155 static inline int pte_young(pte_t pte)
156 {
157 	return pte_get_bits(pte, _PAGE_ACCESSED);
158 }
159 
160 static inline int pte_newpage(pte_t pte)
161 {
162 	return pte_get_bits(pte, _PAGE_NEWPAGE);
163 }
164 
165 static inline int pte_newprot(pte_t pte)
166 {
167 	return(pte_present(pte) && (pte_get_bits(pte, _PAGE_NEWPROT)));
168 }
169 
170 static inline int pte_special(pte_t pte)
171 {
172 	return 0;
173 }
174 
175 /*
176  * =================================
177  * Flags setting section.
178  * =================================
179  */
180 
181 static inline pte_t pte_mknewprot(pte_t pte)
182 {
183 	pte_set_bits(pte, _PAGE_NEWPROT);
184 	return(pte);
185 }
186 
187 static inline pte_t pte_mkclean(pte_t pte)
188 {
189 	pte_clear_bits(pte, _PAGE_DIRTY);
190 	return(pte);
191 }
192 
193 static inline pte_t pte_mkold(pte_t pte)
194 {
195 	pte_clear_bits(pte, _PAGE_ACCESSED);
196 	return(pte);
197 }
198 
199 static inline pte_t pte_wrprotect(pte_t pte)
200 {
201 	if (likely(pte_get_bits(pte, _PAGE_RW)))
202 		pte_clear_bits(pte, _PAGE_RW);
203 	else
204 		return pte;
205 	return(pte_mknewprot(pte));
206 }
207 
208 static inline pte_t pte_mkread(pte_t pte)
209 {
210 	if (unlikely(pte_get_bits(pte, _PAGE_USER)))
211 		return pte;
212 	pte_set_bits(pte, _PAGE_USER);
213 	return(pte_mknewprot(pte));
214 }
215 
216 static inline pte_t pte_mkdirty(pte_t pte)
217 {
218 	pte_set_bits(pte, _PAGE_DIRTY);
219 	return(pte);
220 }
221 
222 static inline pte_t pte_mkyoung(pte_t pte)
223 {
224 	pte_set_bits(pte, _PAGE_ACCESSED);
225 	return(pte);
226 }
227 
228 static inline pte_t pte_mkwrite(pte_t pte)
229 {
230 	if (unlikely(pte_get_bits(pte,  _PAGE_RW)))
231 		return pte;
232 	pte_set_bits(pte, _PAGE_RW);
233 	return(pte_mknewprot(pte));
234 }
235 
236 static inline pte_t pte_mkuptodate(pte_t pte)
237 {
238 	pte_clear_bits(pte, _PAGE_NEWPAGE);
239 	if(pte_present(pte))
240 		pte_clear_bits(pte, _PAGE_NEWPROT);
241 	return(pte);
242 }
243 
244 static inline pte_t pte_mknewpage(pte_t pte)
245 {
246 	pte_set_bits(pte, _PAGE_NEWPAGE);
247 	return(pte);
248 }
249 
250 static inline pte_t pte_mkspecial(pte_t pte)
251 {
252 	return(pte);
253 }
254 
255 static inline void set_pte(pte_t *pteptr, pte_t pteval)
256 {
257 	pte_copy(*pteptr, pteval);
258 
259 	/* If it's a swap entry, it needs to be marked _PAGE_NEWPAGE so
260 	 * fix_range knows to unmap it.  _PAGE_NEWPROT is specific to
261 	 * mapped pages.
262 	 */
263 
264 	*pteptr = pte_mknewpage(*pteptr);
265 	if(pte_present(*pteptr)) *pteptr = pte_mknewprot(*pteptr);
266 }
267 
268 static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
269 			      pte_t *pteptr, pte_t pteval)
270 {
271 	set_pte(pteptr, pteval);
272 }
273 
274 #define __HAVE_ARCH_PTE_SAME
275 static inline int pte_same(pte_t pte_a, pte_t pte_b)
276 {
277 	return !((pte_val(pte_a) ^ pte_val(pte_b)) & ~_PAGE_NEWPAGE);
278 }
279 
280 /*
281  * Conversion functions: convert a page and protection to a page entry,
282  * and a page entry and page directory to the page they refer to.
283  */
284 
285 #define phys_to_page(phys) pfn_to_page(phys_to_pfn(phys))
286 #define __virt_to_page(virt) phys_to_page(__pa(virt))
287 #define page_to_phys(page) pfn_to_phys(page_to_pfn(page))
288 #define virt_to_page(addr) __virt_to_page((const unsigned long) addr)
289 
290 #define mk_pte(page, pgprot) \
291 	({ pte_t pte;					\
292 							\
293 	pte_set_val(pte, page_to_phys(page), (pgprot));	\
294 	if (pte_present(pte))				\
295 		pte_mknewprot(pte_mknewpage(pte));	\
296 	pte;})
297 
298 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
299 {
300 	pte_set_val(pte, (pte_val(pte) & _PAGE_CHG_MASK), newprot);
301 	return pte;
302 }
303 
304 /*
305  * the pgd page can be thought of an array like this: pgd_t[PTRS_PER_PGD]
306  *
307  * this macro returns the index of the entry in the pgd page which would
308  * control the given virtual address
309  */
310 #define pgd_index(address) (((address) >> PGDIR_SHIFT) & (PTRS_PER_PGD-1))
311 
312 /*
313  * pgd_offset() returns a (pgd_t *)
314  * pgd_index() is used get the offset into the pgd page's array of pgd_t's;
315  */
316 #define pgd_offset(mm, address) ((mm)->pgd+pgd_index(address))
317 
318 /*
319  * a shortcut which implies the use of the kernel's pgd, instead
320  * of a process's
321  */
322 #define pgd_offset_k(address) pgd_offset(&init_mm, address)
323 
324 /*
325  * the pmd page can be thought of an array like this: pmd_t[PTRS_PER_PMD]
326  *
327  * this macro returns the index of the entry in the pmd page which would
328  * control the given virtual address
329  */
330 #define pmd_page_vaddr(pmd) ((unsigned long) __va(pmd_val(pmd) & PAGE_MASK))
331 #define pmd_index(address) (((address) >> PMD_SHIFT) & (PTRS_PER_PMD-1))
332 
333 #define pmd_page_vaddr(pmd) \
334 	((unsigned long) __va(pmd_val(pmd) & PAGE_MASK))
335 
336 /*
337  * the pte page can be thought of an array like this: pte_t[PTRS_PER_PTE]
338  *
339  * this macro returns the index of the entry in the pte page which would
340  * control the given virtual address
341  */
342 #define pte_index(address) (((address) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
343 #define pte_offset_kernel(dir, address) \
344 	((pte_t *) pmd_page_vaddr(*(dir)) +  pte_index(address))
345 #define pte_offset_map(dir, address) \
346 	((pte_t *)page_address(pmd_page(*(dir))) + pte_index(address))
347 #define pte_unmap(pte) do { } while (0)
348 
349 struct mm_struct;
350 extern pte_t *virt_to_pte(struct mm_struct *mm, unsigned long addr);
351 
352 #define update_mmu_cache(vma,address,ptep) do ; while (0)
353 
354 /* Encode and de-code a swap entry */
355 #define __swp_type(x)			(((x).val >> 5) & 0x1f)
356 #define __swp_offset(x)			((x).val >> 11)
357 
358 #define __swp_entry(type, offset) \
359 	((swp_entry_t) { ((type) << 5) | ((offset) << 11) })
360 #define __pte_to_swp_entry(pte) \
361 	((swp_entry_t) { pte_val(pte_mkuptodate(pte)) })
362 #define __swp_entry_to_pte(x)		((pte_t) { (x).val })
363 
364 #define kern_addr_valid(addr) (1)
365 
366 #include <asm-generic/pgtable.h>
367 
368 /* Clear a kernel PTE and flush it from the TLB */
369 #define kpte_clear_flush(ptep, vaddr)		\
370 do {						\
371 	pte_clear(&init_mm, (vaddr), (ptep));	\
372 	__flush_tlb_one((vaddr));		\
373 } while (0)
374 
375 #endif
376