xref: /openbmc/linux/arch/um/include/asm/pgtable.h (revision f5cc14e4)
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_KERNEL_RO						\
59 	 (_PAGE_PRESENT | _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 #define PAGE_KERNEL_RO		__pgprot(__PAGE_KERNEL_RO)
67 
68 /*
69  * The i386 can't do page protection for execute, and considers that the same
70  * are read.
71  * Also, write permissions imply read permissions. This is the closest we can
72  * get..
73  */
74 #define __P000	PAGE_NONE
75 #define __P001	PAGE_READONLY
76 #define __P010	PAGE_COPY
77 #define __P011	PAGE_COPY
78 #define __P100	PAGE_READONLY
79 #define __P101	PAGE_READONLY
80 #define __P110	PAGE_COPY
81 #define __P111	PAGE_COPY
82 
83 #define __S000	PAGE_NONE
84 #define __S001	PAGE_READONLY
85 #define __S010	PAGE_SHARED
86 #define __S011	PAGE_SHARED
87 #define __S100	PAGE_READONLY
88 #define __S101	PAGE_READONLY
89 #define __S110	PAGE_SHARED
90 #define __S111	PAGE_SHARED
91 
92 /*
93  * ZERO_PAGE is a global shared page that is always zero: used
94  * for zero-mapped memory areas etc..
95  */
96 #define ZERO_PAGE(vaddr) virt_to_page(empty_zero_page)
97 
98 #define pte_clear(mm,addr,xp) pte_set_val(*(xp), (phys_t) 0, __pgprot(_PAGE_NEWPAGE))
99 
100 #define pmd_none(x)	(!((unsigned long)pmd_val(x) & ~_PAGE_NEWPAGE))
101 #define	pmd_bad(x)	((pmd_val(x) & (~PAGE_MASK & ~_PAGE_USER)) != _KERNPG_TABLE)
102 
103 #define pmd_present(x)	(pmd_val(x) & _PAGE_PRESENT)
104 #define pmd_clear(xp)	do { pmd_val(*(xp)) = _PAGE_NEWPAGE; } while (0)
105 
106 #define pmd_newpage(x)  (pmd_val(x) & _PAGE_NEWPAGE)
107 #define pmd_mkuptodate(x) (pmd_val(x) &= ~_PAGE_NEWPAGE)
108 
109 #define pud_newpage(x)  (pud_val(x) & _PAGE_NEWPAGE)
110 #define pud_mkuptodate(x) (pud_val(x) &= ~_PAGE_NEWPAGE)
111 
112 #define p4d_newpage(x)  (p4d_val(x) & _PAGE_NEWPAGE)
113 #define p4d_mkuptodate(x) (p4d_val(x) &= ~_PAGE_NEWPAGE)
114 
115 #define pmd_page(pmd) phys_to_page(pmd_val(pmd) & PAGE_MASK)
116 
117 #define pte_page(x) pfn_to_page(pte_pfn(x))
118 
119 #define pte_present(x)	pte_get_bits(x, (_PAGE_PRESENT | _PAGE_PROTNONE))
120 
121 /*
122  * =================================
123  * Flags checking section.
124  * =================================
125  */
126 
127 static inline int pte_none(pte_t pte)
128 {
129 	return pte_is_zero(pte);
130 }
131 
132 /*
133  * The following only work if pte_present() is true.
134  * Undefined behaviour if not..
135  */
136 static inline int pte_read(pte_t pte)
137 {
138 	return((pte_get_bits(pte, _PAGE_USER)) &&
139 	       !(pte_get_bits(pte, _PAGE_PROTNONE)));
140 }
141 
142 static inline int pte_exec(pte_t pte){
143 	return((pte_get_bits(pte, _PAGE_USER)) &&
144 	       !(pte_get_bits(pte, _PAGE_PROTNONE)));
145 }
146 
147 static inline int pte_write(pte_t pte)
148 {
149 	return((pte_get_bits(pte, _PAGE_RW)) &&
150 	       !(pte_get_bits(pte, _PAGE_PROTNONE)));
151 }
152 
153 static inline int pte_dirty(pte_t pte)
154 {
155 	return pte_get_bits(pte, _PAGE_DIRTY);
156 }
157 
158 static inline int pte_young(pte_t pte)
159 {
160 	return pte_get_bits(pte, _PAGE_ACCESSED);
161 }
162 
163 static inline int pte_newpage(pte_t pte)
164 {
165 	return pte_get_bits(pte, _PAGE_NEWPAGE);
166 }
167 
168 static inline int pte_newprot(pte_t pte)
169 {
170 	return(pte_present(pte) && (pte_get_bits(pte, _PAGE_NEWPROT)));
171 }
172 
173 /*
174  * =================================
175  * Flags setting section.
176  * =================================
177  */
178 
179 static inline pte_t pte_mknewprot(pte_t pte)
180 {
181 	pte_set_bits(pte, _PAGE_NEWPROT);
182 	return(pte);
183 }
184 
185 static inline pte_t pte_mkclean(pte_t pte)
186 {
187 	pte_clear_bits(pte, _PAGE_DIRTY);
188 	return(pte);
189 }
190 
191 static inline pte_t pte_mkold(pte_t pte)
192 {
193 	pte_clear_bits(pte, _PAGE_ACCESSED);
194 	return(pte);
195 }
196 
197 static inline pte_t pte_wrprotect(pte_t pte)
198 {
199 	if (likely(pte_get_bits(pte, _PAGE_RW)))
200 		pte_clear_bits(pte, _PAGE_RW);
201 	else
202 		return pte;
203 	return(pte_mknewprot(pte));
204 }
205 
206 static inline pte_t pte_mkread(pte_t pte)
207 {
208 	if (unlikely(pte_get_bits(pte, _PAGE_USER)))
209 		return pte;
210 	pte_set_bits(pte, _PAGE_USER);
211 	return(pte_mknewprot(pte));
212 }
213 
214 static inline pte_t pte_mkdirty(pte_t pte)
215 {
216 	pte_set_bits(pte, _PAGE_DIRTY);
217 	return(pte);
218 }
219 
220 static inline pte_t pte_mkyoung(pte_t pte)
221 {
222 	pte_set_bits(pte, _PAGE_ACCESSED);
223 	return(pte);
224 }
225 
226 static inline pte_t pte_mkwrite(pte_t pte)
227 {
228 	if (unlikely(pte_get_bits(pte,  _PAGE_RW)))
229 		return pte;
230 	pte_set_bits(pte, _PAGE_RW);
231 	return(pte_mknewprot(pte));
232 }
233 
234 static inline pte_t pte_mkuptodate(pte_t pte)
235 {
236 	pte_clear_bits(pte, _PAGE_NEWPAGE);
237 	if(pte_present(pte))
238 		pte_clear_bits(pte, _PAGE_NEWPROT);
239 	return(pte);
240 }
241 
242 static inline pte_t pte_mknewpage(pte_t pte)
243 {
244 	pte_set_bits(pte, _PAGE_NEWPAGE);
245 	return(pte);
246 }
247 
248 static inline void set_pte(pte_t *pteptr, pte_t pteval)
249 {
250 	pte_copy(*pteptr, pteval);
251 
252 	/* If it's a swap entry, it needs to be marked _PAGE_NEWPAGE so
253 	 * fix_range knows to unmap it.  _PAGE_NEWPROT is specific to
254 	 * mapped pages.
255 	 */
256 
257 	*pteptr = pte_mknewpage(*pteptr);
258 	if(pte_present(*pteptr)) *pteptr = pte_mknewprot(*pteptr);
259 }
260 
261 static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
262 			      pte_t *pteptr, pte_t pteval)
263 {
264 	set_pte(pteptr, pteval);
265 }
266 
267 #define __HAVE_ARCH_PTE_SAME
268 static inline int pte_same(pte_t pte_a, pte_t pte_b)
269 {
270 	return !((pte_val(pte_a) ^ pte_val(pte_b)) & ~_PAGE_NEWPAGE);
271 }
272 
273 /*
274  * Conversion functions: convert a page and protection to a page entry,
275  * and a page entry and page directory to the page they refer to.
276  */
277 
278 #define phys_to_page(phys) pfn_to_page(phys_to_pfn(phys))
279 #define __virt_to_page(virt) phys_to_page(__pa(virt))
280 #define page_to_phys(page) pfn_to_phys(page_to_pfn(page))
281 #define virt_to_page(addr) __virt_to_page((const unsigned long) addr)
282 
283 #define mk_pte(page, pgprot) \
284 	({ pte_t pte;					\
285 							\
286 	pte_set_val(pte, page_to_phys(page), (pgprot));	\
287 	if (pte_present(pte))				\
288 		pte_mknewprot(pte_mknewpage(pte));	\
289 	pte;})
290 
291 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
292 {
293 	pte_set_val(pte, (pte_val(pte) & _PAGE_CHG_MASK), newprot);
294 	return pte;
295 }
296 
297 /*
298  * the pmd page can be thought of an array like this: pmd_t[PTRS_PER_PMD]
299  *
300  * this macro returns the index of the entry in the pmd page which would
301  * control the given virtual address
302  */
303 #define pmd_page_vaddr(pmd) ((unsigned long) __va(pmd_val(pmd) & PAGE_MASK))
304 
305 struct mm_struct;
306 extern pte_t *virt_to_pte(struct mm_struct *mm, unsigned long addr);
307 
308 #define update_mmu_cache(vma,address,ptep) do ; while (0)
309 
310 /* Encode and de-code a swap entry */
311 #define __swp_type(x)			(((x).val >> 5) & 0x1f)
312 #define __swp_offset(x)			((x).val >> 11)
313 
314 #define __swp_entry(type, offset) \
315 	((swp_entry_t) { ((type) << 5) | ((offset) << 11) })
316 #define __pte_to_swp_entry(pte) \
317 	((swp_entry_t) { pte_val(pte_mkuptodate(pte)) })
318 #define __swp_entry_to_pte(x)		((pte_t) { (x).val })
319 
320 #define kern_addr_valid(addr) (1)
321 
322 /* Clear a kernel PTE and flush it from the TLB */
323 #define kpte_clear_flush(ptep, vaddr)		\
324 do {						\
325 	pte_clear(&init_mm, (vaddr), (ptep));	\
326 	__flush_tlb_one((vaddr));		\
327 } while (0)
328 
329 #endif
330