xref: /openbmc/linux/arch/um/include/asm/pgtable.h (revision cef69974)
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_pfn(pmd) (pmd_val(pmd) >> PAGE_SHIFT)
113 #define pmd_page(pmd) phys_to_page(pmd_val(pmd) & PAGE_MASK)
114 
115 #define pte_page(x) pfn_to_page(pte_pfn(x))
116 
117 #define pte_present(x)	pte_get_bits(x, (_PAGE_PRESENT | _PAGE_PROTNONE))
118 
119 /*
120  * =================================
121  * Flags checking section.
122  * =================================
123  */
124 
125 static inline int pte_none(pte_t pte)
126 {
127 	return pte_is_zero(pte);
128 }
129 
130 /*
131  * The following only work if pte_present() is true.
132  * Undefined behaviour if not..
133  */
134 static inline int pte_read(pte_t pte)
135 {
136 	return((pte_get_bits(pte, _PAGE_USER)) &&
137 	       !(pte_get_bits(pte, _PAGE_PROTNONE)));
138 }
139 
140 static inline int pte_exec(pte_t pte){
141 	return((pte_get_bits(pte, _PAGE_USER)) &&
142 	       !(pte_get_bits(pte, _PAGE_PROTNONE)));
143 }
144 
145 static inline int pte_write(pte_t pte)
146 {
147 	return((pte_get_bits(pte, _PAGE_RW)) &&
148 	       !(pte_get_bits(pte, _PAGE_PROTNONE)));
149 }
150 
151 static inline int pte_dirty(pte_t pte)
152 {
153 	return pte_get_bits(pte, _PAGE_DIRTY);
154 }
155 
156 static inline int pte_young(pte_t pte)
157 {
158 	return pte_get_bits(pte, _PAGE_ACCESSED);
159 }
160 
161 static inline int pte_newpage(pte_t pte)
162 {
163 	return pte_get_bits(pte, _PAGE_NEWPAGE);
164 }
165 
166 static inline int pte_newprot(pte_t pte)
167 {
168 	return(pte_present(pte) && (pte_get_bits(pte, _PAGE_NEWPROT)));
169 }
170 
171 /*
172  * =================================
173  * Flags setting section.
174  * =================================
175  */
176 
177 static inline pte_t pte_mknewprot(pte_t pte)
178 {
179 	pte_set_bits(pte, _PAGE_NEWPROT);
180 	return(pte);
181 }
182 
183 static inline pte_t pte_mkclean(pte_t pte)
184 {
185 	pte_clear_bits(pte, _PAGE_DIRTY);
186 	return(pte);
187 }
188 
189 static inline pte_t pte_mkold(pte_t pte)
190 {
191 	pte_clear_bits(pte, _PAGE_ACCESSED);
192 	return(pte);
193 }
194 
195 static inline pte_t pte_wrprotect(pte_t pte)
196 {
197 	if (likely(pte_get_bits(pte, _PAGE_RW)))
198 		pte_clear_bits(pte, _PAGE_RW);
199 	else
200 		return pte;
201 	return(pte_mknewprot(pte));
202 }
203 
204 static inline pte_t pte_mkread(pte_t pte)
205 {
206 	if (unlikely(pte_get_bits(pte, _PAGE_USER)))
207 		return pte;
208 	pte_set_bits(pte, _PAGE_USER);
209 	return(pte_mknewprot(pte));
210 }
211 
212 static inline pte_t pte_mkdirty(pte_t pte)
213 {
214 	pte_set_bits(pte, _PAGE_DIRTY);
215 	return(pte);
216 }
217 
218 static inline pte_t pte_mkyoung(pte_t pte)
219 {
220 	pte_set_bits(pte, _PAGE_ACCESSED);
221 	return(pte);
222 }
223 
224 static inline pte_t pte_mkwrite(pte_t pte)
225 {
226 	if (unlikely(pte_get_bits(pte,  _PAGE_RW)))
227 		return pte;
228 	pte_set_bits(pte, _PAGE_RW);
229 	return(pte_mknewprot(pte));
230 }
231 
232 static inline pte_t pte_mkuptodate(pte_t pte)
233 {
234 	pte_clear_bits(pte, _PAGE_NEWPAGE);
235 	if(pte_present(pte))
236 		pte_clear_bits(pte, _PAGE_NEWPROT);
237 	return(pte);
238 }
239 
240 static inline pte_t pte_mknewpage(pte_t pte)
241 {
242 	pte_set_bits(pte, _PAGE_NEWPAGE);
243 	return(pte);
244 }
245 
246 static inline void set_pte(pte_t *pteptr, pte_t pteval)
247 {
248 	pte_copy(*pteptr, pteval);
249 
250 	/* If it's a swap entry, it needs to be marked _PAGE_NEWPAGE so
251 	 * fix_range knows to unmap it.  _PAGE_NEWPROT is specific to
252 	 * mapped pages.
253 	 */
254 
255 	*pteptr = pte_mknewpage(*pteptr);
256 	if(pte_present(*pteptr)) *pteptr = pte_mknewprot(*pteptr);
257 }
258 
259 static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
260 			      pte_t *pteptr, pte_t pteval)
261 {
262 	set_pte(pteptr, pteval);
263 }
264 
265 #define __HAVE_ARCH_PTE_SAME
266 static inline int pte_same(pte_t pte_a, pte_t pte_b)
267 {
268 	return !((pte_val(pte_a) ^ pte_val(pte_b)) & ~_PAGE_NEWPAGE);
269 }
270 
271 /*
272  * Conversion functions: convert a page and protection to a page entry,
273  * and a page entry and page directory to the page they refer to.
274  */
275 
276 #define phys_to_page(phys) pfn_to_page(phys_to_pfn(phys))
277 #define __virt_to_page(virt) phys_to_page(__pa(virt))
278 #define page_to_phys(page) pfn_to_phys(page_to_pfn(page))
279 #define virt_to_page(addr) __virt_to_page((const unsigned long) addr)
280 
281 #define mk_pte(page, pgprot) \
282 	({ pte_t pte;					\
283 							\
284 	pte_set_val(pte, page_to_phys(page), (pgprot));	\
285 	if (pte_present(pte))				\
286 		pte_mknewprot(pte_mknewpage(pte));	\
287 	pte;})
288 
289 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
290 {
291 	pte_set_val(pte, (pte_val(pte) & _PAGE_CHG_MASK), newprot);
292 	return pte;
293 }
294 
295 /*
296  * the pmd page can be thought of an array like this: pmd_t[PTRS_PER_PMD]
297  *
298  * this macro returns the index of the entry in the pmd page which would
299  * control the given virtual address
300  */
301 #define pmd_page_vaddr(pmd) ((unsigned long) __va(pmd_val(pmd) & PAGE_MASK))
302 
303 struct mm_struct;
304 extern pte_t *virt_to_pte(struct mm_struct *mm, unsigned long addr);
305 
306 #define update_mmu_cache(vma,address,ptep) do {} while (0)
307 
308 /* Encode and de-code a swap entry */
309 #define __swp_type(x)			(((x).val >> 5) & 0x1f)
310 #define __swp_offset(x)			((x).val >> 11)
311 
312 #define __swp_entry(type, offset) \
313 	((swp_entry_t) { ((type) << 5) | ((offset) << 11) })
314 #define __pte_to_swp_entry(pte) \
315 	((swp_entry_t) { pte_val(pte_mkuptodate(pte)) })
316 #define __swp_entry_to_pte(x)		((pte_t) { (x).val })
317 
318 #define kern_addr_valid(addr) (1)
319 
320 /* Clear a kernel PTE and flush it from the TLB */
321 #define kpte_clear_flush(ptep, vaddr)		\
322 do {						\
323 	pte_clear(&init_mm, (vaddr), (ptep));	\
324 	__flush_tlb_one((vaddr));		\
325 } while (0)
326 
327 #endif
328