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/* We borrow bit 10 to store the exclusive marker in swap PTEs. */
25#define _PAGE_SWP_EXCLUSIVE	0x400
26
27#ifdef CONFIG_3_LEVEL_PGTABLES
28#include <asm/pgtable-3level.h>
29#else
30#include <asm/pgtable-2level.h>
31#endif
32
33extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
34
35/* zero page used for uninitialized stuff */
36extern unsigned long *empty_zero_page;
37
38/* Just any arbitrary offset to the start of the vmalloc VM area: the
39 * current 8MB value just means that there will be a 8MB "hole" after the
40 * physical memory until the kernel virtual memory starts.  That means that
41 * any out-of-bounds memory accesses will hopefully be caught.
42 * The vmalloc() routines leaves a hole of 4kB between each vmalloced
43 * area for the same reason. ;)
44 */
45
46extern unsigned long end_iomem;
47
48#define VMALLOC_OFFSET	(__va_space)
49#define VMALLOC_START ((end_iomem + VMALLOC_OFFSET) & ~(VMALLOC_OFFSET-1))
50#define PKMAP_BASE ((FIXADDR_START - LAST_PKMAP * PAGE_SIZE) & PMD_MASK)
51#define VMALLOC_END	(FIXADDR_START-2*PAGE_SIZE)
52#define MODULES_VADDR	VMALLOC_START
53#define MODULES_END	VMALLOC_END
54#define MODULES_LEN	(MODULES_VADDR - MODULES_END)
55
56#define _PAGE_TABLE	(_PAGE_PRESENT | _PAGE_RW | _PAGE_USER | _PAGE_ACCESSED | _PAGE_DIRTY)
57#define _KERNPG_TABLE	(_PAGE_PRESENT | _PAGE_RW | _PAGE_ACCESSED | _PAGE_DIRTY)
58#define _PAGE_CHG_MASK	(PAGE_MASK | _PAGE_ACCESSED | _PAGE_DIRTY)
59#define __PAGE_KERNEL_EXEC                                              \
60	 (_PAGE_PRESENT | _PAGE_RW | _PAGE_DIRTY | _PAGE_ACCESSED)
61#define PAGE_NONE	__pgprot(_PAGE_PROTNONE | _PAGE_ACCESSED)
62#define PAGE_SHARED	__pgprot(_PAGE_PRESENT | _PAGE_RW | _PAGE_USER | _PAGE_ACCESSED)
63#define PAGE_COPY	__pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_ACCESSED)
64#define PAGE_READONLY	__pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_ACCESSED)
65#define PAGE_KERNEL	__pgprot(_PAGE_PRESENT | _PAGE_RW | _PAGE_DIRTY | _PAGE_ACCESSED)
66#define PAGE_KERNEL_EXEC	__pgprot(__PAGE_KERNEL_EXEC)
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
75/*
76 * ZERO_PAGE is a global shared page that is always zero: used
77 * for zero-mapped memory areas etc..
78 */
79#define ZERO_PAGE(vaddr) virt_to_page(empty_zero_page)
80
81#define pte_clear(mm,addr,xp) pte_set_val(*(xp), (phys_t) 0, __pgprot(_PAGE_NEWPAGE))
82
83#define pmd_none(x)	(!((unsigned long)pmd_val(x) & ~_PAGE_NEWPAGE))
84#define	pmd_bad(x)	((pmd_val(x) & (~PAGE_MASK & ~_PAGE_USER)) != _KERNPG_TABLE)
85
86#define pmd_present(x)	(pmd_val(x) & _PAGE_PRESENT)
87#define pmd_clear(xp)	do { pmd_val(*(xp)) = _PAGE_NEWPAGE; } while (0)
88
89#define pmd_newpage(x)  (pmd_val(x) & _PAGE_NEWPAGE)
90#define pmd_mkuptodate(x) (pmd_val(x) &= ~_PAGE_NEWPAGE)
91
92#define pud_newpage(x)  (pud_val(x) & _PAGE_NEWPAGE)
93#define pud_mkuptodate(x) (pud_val(x) &= ~_PAGE_NEWPAGE)
94
95#define p4d_newpage(x)  (p4d_val(x) & _PAGE_NEWPAGE)
96#define p4d_mkuptodate(x) (p4d_val(x) &= ~_PAGE_NEWPAGE)
97
98#define pmd_pfn(pmd) (pmd_val(pmd) >> PAGE_SHIFT)
99#define pmd_page(pmd) phys_to_page(pmd_val(pmd) & PAGE_MASK)
100
101#define pte_page(x) pfn_to_page(pte_pfn(x))
102
103#define pte_present(x)	pte_get_bits(x, (_PAGE_PRESENT | _PAGE_PROTNONE))
104
105/*
106 * =================================
107 * Flags checking section.
108 * =================================
109 */
110
111static inline int pte_none(pte_t pte)
112{
113	return pte_is_zero(pte);
114}
115
116/*
117 * The following only work if pte_present() is true.
118 * Undefined behaviour if not..
119 */
120static inline int pte_read(pte_t pte)
121{
122	return((pte_get_bits(pte, _PAGE_USER)) &&
123	       !(pte_get_bits(pte, _PAGE_PROTNONE)));
124}
125
126static inline int pte_exec(pte_t pte){
127	return((pte_get_bits(pte, _PAGE_USER)) &&
128	       !(pte_get_bits(pte, _PAGE_PROTNONE)));
129}
130
131static inline int pte_write(pte_t pte)
132{
133	return((pte_get_bits(pte, _PAGE_RW)) &&
134	       !(pte_get_bits(pte, _PAGE_PROTNONE)));
135}
136
137static inline int pte_dirty(pte_t pte)
138{
139	return pte_get_bits(pte, _PAGE_DIRTY);
140}
141
142static inline int pte_young(pte_t pte)
143{
144	return pte_get_bits(pte, _PAGE_ACCESSED);
145}
146
147static inline int pte_newpage(pte_t pte)
148{
149	return pte_get_bits(pte, _PAGE_NEWPAGE);
150}
151
152static inline int pte_newprot(pte_t pte)
153{
154	return(pte_present(pte) && (pte_get_bits(pte, _PAGE_NEWPROT)));
155}
156
157/*
158 * =================================
159 * Flags setting section.
160 * =================================
161 */
162
163static inline pte_t pte_mknewprot(pte_t pte)
164{
165	pte_set_bits(pte, _PAGE_NEWPROT);
166	return(pte);
167}
168
169static inline pte_t pte_mkclean(pte_t pte)
170{
171	pte_clear_bits(pte, _PAGE_DIRTY);
172	return(pte);
173}
174
175static inline pte_t pte_mkold(pte_t pte)
176{
177	pte_clear_bits(pte, _PAGE_ACCESSED);
178	return(pte);
179}
180
181static inline pte_t pte_wrprotect(pte_t pte)
182{
183	if (likely(pte_get_bits(pte, _PAGE_RW)))
184		pte_clear_bits(pte, _PAGE_RW);
185	else
186		return pte;
187	return(pte_mknewprot(pte));
188}
189
190static inline pte_t pte_mkread(pte_t pte)
191{
192	if (unlikely(pte_get_bits(pte, _PAGE_USER)))
193		return pte;
194	pte_set_bits(pte, _PAGE_USER);
195	return(pte_mknewprot(pte));
196}
197
198static inline pte_t pte_mkdirty(pte_t pte)
199{
200	pte_set_bits(pte, _PAGE_DIRTY);
201	return(pte);
202}
203
204static inline pte_t pte_mkyoung(pte_t pte)
205{
206	pte_set_bits(pte, _PAGE_ACCESSED);
207	return(pte);
208}
209
210static inline pte_t pte_mkwrite_novma(pte_t pte)
211{
212	if (unlikely(pte_get_bits(pte,  _PAGE_RW)))
213		return pte;
214	pte_set_bits(pte, _PAGE_RW);
215	return(pte_mknewprot(pte));
216}
217
218static inline pte_t pte_mkuptodate(pte_t pte)
219{
220	pte_clear_bits(pte, _PAGE_NEWPAGE);
221	if(pte_present(pte))
222		pte_clear_bits(pte, _PAGE_NEWPROT);
223	return(pte);
224}
225
226static inline pte_t pte_mknewpage(pte_t pte)
227{
228	pte_set_bits(pte, _PAGE_NEWPAGE);
229	return(pte);
230}
231
232static inline void set_pte(pte_t *pteptr, pte_t pteval)
233{
234	pte_copy(*pteptr, pteval);
235
236	/* If it's a swap entry, it needs to be marked _PAGE_NEWPAGE so
237	 * fix_range knows to unmap it.  _PAGE_NEWPROT is specific to
238	 * mapped pages.
239	 */
240
241	*pteptr = pte_mknewpage(*pteptr);
242	if(pte_present(*pteptr)) *pteptr = pte_mknewprot(*pteptr);
243}
244
245#define PFN_PTE_SHIFT		PAGE_SHIFT
246
247#define __HAVE_ARCH_PTE_SAME
248static inline int pte_same(pte_t pte_a, pte_t pte_b)
249{
250	return !((pte_val(pte_a) ^ pte_val(pte_b)) & ~_PAGE_NEWPAGE);
251}
252
253/*
254 * Conversion functions: convert a page and protection to a page entry,
255 * and a page entry and page directory to the page they refer to.
256 */
257
258#define phys_to_page(phys) pfn_to_page(phys_to_pfn(phys))
259#define __virt_to_page(virt) phys_to_page(__pa(virt))
260#define page_to_phys(page) pfn_to_phys(page_to_pfn(page))
261#define virt_to_page(addr) __virt_to_page((const unsigned long) addr)
262
263#define mk_pte(page, pgprot) \
264	({ pte_t pte;					\
265							\
266	pte_set_val(pte, page_to_phys(page), (pgprot));	\
267	if (pte_present(pte))				\
268		pte_mknewprot(pte_mknewpage(pte));	\
269	pte;})
270
271static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
272{
273	pte_set_val(pte, (pte_val(pte) & _PAGE_CHG_MASK), newprot);
274	return pte;
275}
276
277/*
278 * the pmd page can be thought of an array like this: pmd_t[PTRS_PER_PMD]
279 *
280 * this macro returns the index of the entry in the pmd page which would
281 * control the given virtual address
282 */
283#define pmd_page_vaddr(pmd) ((unsigned long) __va(pmd_val(pmd) & PAGE_MASK))
284
285struct mm_struct;
286extern pte_t *virt_to_pte(struct mm_struct *mm, unsigned long addr);
287
288#define update_mmu_cache(vma,address,ptep) do {} while (0)
289#define update_mmu_cache_range(vmf, vma, address, ptep, nr) do {} while (0)
290
291/*
292 * Encode/decode swap entries and swap PTEs. Swap PTEs are all PTEs that
293 * are !pte_none() && !pte_present().
294 *
295 * Format of swap PTEs:
296 *
297 *   3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1
298 *   1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0
299 *   <--------------- offset ----------------> E < type -> 0 0 0 1 0
300 *
301 *   E is the exclusive marker that is not stored in swap entries.
302 *   _PAGE_NEWPAGE (bit 1) is always set to 1 in set_pte().
303 */
304#define __swp_type(x)			(((x).val >> 5) & 0x1f)
305#define __swp_offset(x)			((x).val >> 11)
306
307#define __swp_entry(type, offset) \
308	((swp_entry_t) { (((type) & 0x1f) << 5) | ((offset) << 11) })
309#define __pte_to_swp_entry(pte) \
310	((swp_entry_t) { pte_val(pte_mkuptodate(pte)) })
311#define __swp_entry_to_pte(x)		((pte_t) { (x).val })
312
313static inline int pte_swp_exclusive(pte_t pte)
314{
315	return pte_get_bits(pte, _PAGE_SWP_EXCLUSIVE);
316}
317
318static inline pte_t pte_swp_mkexclusive(pte_t pte)
319{
320	pte_set_bits(pte, _PAGE_SWP_EXCLUSIVE);
321	return pte;
322}
323
324static inline pte_t pte_swp_clear_exclusive(pte_t pte)
325{
326	pte_clear_bits(pte, _PAGE_SWP_EXCLUSIVE);
327	return pte;
328}
329
330/* Clear a kernel PTE and flush it from the TLB */
331#define kpte_clear_flush(ptep, vaddr)		\
332do {						\
333	pte_clear(&init_mm, (vaddr), (ptep));	\
334	__flush_tlb_one((vaddr));		\
335} while (0)
336
337#endif
338