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v5.9
  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
 30extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
 31
 32/* zero page used for uninitialized stuff */
 33extern 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
 43extern 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
124static 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 */
133static 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
139static inline int pte_exec(pte_t pte){
140	return((pte_get_bits(pte, _PAGE_USER)) &&
141	       !(pte_get_bits(pte, _PAGE_PROTNONE)));
142}
143
144static 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
150static inline int pte_dirty(pte_t pte)
151{
152	return pte_get_bits(pte, _PAGE_DIRTY);
153}
154
155static inline int pte_young(pte_t pte)
156{
157	return pte_get_bits(pte, _PAGE_ACCESSED);
158}
159
160static inline int pte_newpage(pte_t pte)
161{
162	return pte_get_bits(pte, _PAGE_NEWPAGE);
163}
164
165static inline int pte_newprot(pte_t pte)
166{
167	return(pte_present(pte) && (pte_get_bits(pte, _PAGE_NEWPROT)));
168}
169
170/*
171 * =================================
172 * Flags setting section.
173 * =================================
174 */
175
176static inline pte_t pte_mknewprot(pte_t pte)
177{
178	pte_set_bits(pte, _PAGE_NEWPROT);
179	return(pte);
180}
181
182static inline pte_t pte_mkclean(pte_t pte)
183{
184	pte_clear_bits(pte, _PAGE_DIRTY);
185	return(pte);
186}
187
188static inline pte_t pte_mkold(pte_t pte)
189{
190	pte_clear_bits(pte, _PAGE_ACCESSED);
191	return(pte);
192}
193
194static inline pte_t pte_wrprotect(pte_t pte)
195{
196	if (likely(pte_get_bits(pte, _PAGE_RW)))
197		pte_clear_bits(pte, _PAGE_RW);
198	else
199		return pte;
200	return(pte_mknewprot(pte));
201}
202
203static inline pte_t pte_mkread(pte_t pte)
204{
205	if (unlikely(pte_get_bits(pte, _PAGE_USER)))
206		return pte;
207	pte_set_bits(pte, _PAGE_USER);
208	return(pte_mknewprot(pte));
209}
210
211static inline pte_t pte_mkdirty(pte_t pte)
212{
213	pte_set_bits(pte, _PAGE_DIRTY);
214	return(pte);
215}
216
217static inline pte_t pte_mkyoung(pte_t pte)
218{
219	pte_set_bits(pte, _PAGE_ACCESSED);
220	return(pte);
221}
222
223static inline pte_t pte_mkwrite(pte_t pte)
224{
225	if (unlikely(pte_get_bits(pte,  _PAGE_RW)))
226		return pte;
227	pte_set_bits(pte, _PAGE_RW);
228	return(pte_mknewprot(pte));
229}
230
231static inline pte_t pte_mkuptodate(pte_t pte)
232{
233	pte_clear_bits(pte, _PAGE_NEWPAGE);
234	if(pte_present(pte))
235		pte_clear_bits(pte, _PAGE_NEWPROT);
236	return(pte);
237}
238
239static inline pte_t pte_mknewpage(pte_t pte)
240{
241	pte_set_bits(pte, _PAGE_NEWPAGE);
242	return(pte);
243}
244
245static inline void set_pte(pte_t *pteptr, pte_t pteval)
246{
247	pte_copy(*pteptr, pteval);
248
249	/* If it's a swap entry, it needs to be marked _PAGE_NEWPAGE so
250	 * fix_range knows to unmap it.  _PAGE_NEWPROT is specific to
251	 * mapped pages.
252	 */
253
254	*pteptr = pte_mknewpage(*pteptr);
255	if(pte_present(*pteptr)) *pteptr = pte_mknewprot(*pteptr);
256}
257
258static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
259			      pte_t *pteptr, pte_t pteval)
260{
261	set_pte(pteptr, pteval);
262}
263
264#define __HAVE_ARCH_PTE_SAME
265static inline int pte_same(pte_t pte_a, pte_t pte_b)
266{
267	return !((pte_val(pte_a) ^ pte_val(pte_b)) & ~_PAGE_NEWPAGE);
268}
269
270/*
271 * Conversion functions: convert a page and protection to a page entry,
272 * and a page entry and page directory to the page they refer to.
273 */
274
275#define phys_to_page(phys) pfn_to_page(phys_to_pfn(phys))
276#define __virt_to_page(virt) phys_to_page(__pa(virt))
277#define page_to_phys(page) pfn_to_phys(page_to_pfn(page))
278#define virt_to_page(addr) __virt_to_page((const unsigned long) addr)
279
280#define mk_pte(page, pgprot) \
281	({ pte_t pte;					\
282							\
283	pte_set_val(pte, page_to_phys(page), (pgprot));	\
284	if (pte_present(pte))				\
285		pte_mknewprot(pte_mknewpage(pte));	\
286	pte;})
287
288static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
289{
290	pte_set_val(pte, (pte_val(pte) & _PAGE_CHG_MASK), newprot);
291	return pte;
292}
293
294/*
295 * the pmd page can be thought of an array like this: pmd_t[PTRS_PER_PMD]
296 *
297 * this macro returns the index of the entry in the pmd page which would
298 * control the given virtual address
299 */
300#define pmd_page_vaddr(pmd) ((unsigned long) __va(pmd_val(pmd) & PAGE_MASK))
301
302struct mm_struct;
303extern pte_t *virt_to_pte(struct mm_struct *mm, unsigned long addr);
304
305#define update_mmu_cache(vma,address,ptep) do ; while (0)
306
307/* Encode and de-code a swap entry */
308#define __swp_type(x)			(((x).val >> 5) & 0x1f)
309#define __swp_offset(x)			((x).val >> 11)
310
311#define __swp_entry(type, offset) \
312	((swp_entry_t) { ((type) << 5) | ((offset) << 11) })
313#define __pte_to_swp_entry(pte) \
314	((swp_entry_t) { pte_val(pte_mkuptodate(pte)) })
315#define __swp_entry_to_pte(x)		((pte_t) { (x).val })
316
317#define kern_addr_valid(addr) (1)
318
319/* Clear a kernel PTE and flush it from the TLB */
320#define kpte_clear_flush(ptep, vaddr)		\
321do {						\
322	pte_clear(&init_mm, (vaddr), (ptep));	\
323	__flush_tlb_one((vaddr));		\
324} while (0)
325
326#endif
v6.2
  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
 30extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
 31
 32/* zero page used for uninitialized stuff */
 33extern 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
 43extern 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
 72/*
 73 * ZERO_PAGE is a global shared page that is always zero: used
 74 * for zero-mapped memory areas etc..
 75 */
 76#define ZERO_PAGE(vaddr) virt_to_page(empty_zero_page)
 77
 78#define pte_clear(mm,addr,xp) pte_set_val(*(xp), (phys_t) 0, __pgprot(_PAGE_NEWPAGE))
 79
 80#define pmd_none(x)	(!((unsigned long)pmd_val(x) & ~_PAGE_NEWPAGE))
 81#define	pmd_bad(x)	((pmd_val(x) & (~PAGE_MASK & ~_PAGE_USER)) != _KERNPG_TABLE)
 82
 83#define pmd_present(x)	(pmd_val(x) & _PAGE_PRESENT)
 84#define pmd_clear(xp)	do { pmd_val(*(xp)) = _PAGE_NEWPAGE; } while (0)
 85
 86#define pmd_newpage(x)  (pmd_val(x) & _PAGE_NEWPAGE)
 87#define pmd_mkuptodate(x) (pmd_val(x) &= ~_PAGE_NEWPAGE)
 88
 89#define pud_newpage(x)  (pud_val(x) & _PAGE_NEWPAGE)
 90#define pud_mkuptodate(x) (pud_val(x) &= ~_PAGE_NEWPAGE)
 91
 92#define p4d_newpage(x)  (p4d_val(x) & _PAGE_NEWPAGE)
 93#define p4d_mkuptodate(x) (p4d_val(x) &= ~_PAGE_NEWPAGE)
 94
 95#define pmd_pfn(pmd) (pmd_val(pmd) >> PAGE_SHIFT)
 96#define pmd_page(pmd) phys_to_page(pmd_val(pmd) & PAGE_MASK)
 97
 98#define pte_page(x) pfn_to_page(pte_pfn(x))
 99
100#define pte_present(x)	pte_get_bits(x, (_PAGE_PRESENT | _PAGE_PROTNONE))
101
102/*
103 * =================================
104 * Flags checking section.
105 * =================================
106 */
107
108static inline int pte_none(pte_t pte)
109{
110	return pte_is_zero(pte);
111}
112
113/*
114 * The following only work if pte_present() is true.
115 * Undefined behaviour if not..
116 */
117static inline int pte_read(pte_t pte)
118{
119	return((pte_get_bits(pte, _PAGE_USER)) &&
120	       !(pte_get_bits(pte, _PAGE_PROTNONE)));
121}
122
123static inline int pte_exec(pte_t pte){
124	return((pte_get_bits(pte, _PAGE_USER)) &&
125	       !(pte_get_bits(pte, _PAGE_PROTNONE)));
126}
127
128static inline int pte_write(pte_t pte)
129{
130	return((pte_get_bits(pte, _PAGE_RW)) &&
131	       !(pte_get_bits(pte, _PAGE_PROTNONE)));
132}
133
134static inline int pte_dirty(pte_t pte)
135{
136	return pte_get_bits(pte, _PAGE_DIRTY);
137}
138
139static inline int pte_young(pte_t pte)
140{
141	return pte_get_bits(pte, _PAGE_ACCESSED);
142}
143
144static inline int pte_newpage(pte_t pte)
145{
146	return pte_get_bits(pte, _PAGE_NEWPAGE);
147}
148
149static inline int pte_newprot(pte_t pte)
150{
151	return(pte_present(pte) && (pte_get_bits(pte, _PAGE_NEWPROT)));
152}
153
154/*
155 * =================================
156 * Flags setting section.
157 * =================================
158 */
159
160static inline pte_t pte_mknewprot(pte_t pte)
161{
162	pte_set_bits(pte, _PAGE_NEWPROT);
163	return(pte);
164}
165
166static inline pte_t pte_mkclean(pte_t pte)
167{
168	pte_clear_bits(pte, _PAGE_DIRTY);
169	return(pte);
170}
171
172static inline pte_t pte_mkold(pte_t pte)
173{
174	pte_clear_bits(pte, _PAGE_ACCESSED);
175	return(pte);
176}
177
178static inline pte_t pte_wrprotect(pte_t pte)
179{
180	if (likely(pte_get_bits(pte, _PAGE_RW)))
181		pte_clear_bits(pte, _PAGE_RW);
182	else
183		return pte;
184	return(pte_mknewprot(pte));
185}
186
187static inline pte_t pte_mkread(pte_t pte)
188{
189	if (unlikely(pte_get_bits(pte, _PAGE_USER)))
190		return pte;
191	pte_set_bits(pte, _PAGE_USER);
192	return(pte_mknewprot(pte));
193}
194
195static inline pte_t pte_mkdirty(pte_t pte)
196{
197	pte_set_bits(pte, _PAGE_DIRTY);
198	return(pte);
199}
200
201static inline pte_t pte_mkyoung(pte_t pte)
202{
203	pte_set_bits(pte, _PAGE_ACCESSED);
204	return(pte);
205}
206
207static inline pte_t pte_mkwrite(pte_t pte)
208{
209	if (unlikely(pte_get_bits(pte,  _PAGE_RW)))
210		return pte;
211	pte_set_bits(pte, _PAGE_RW);
212	return(pte_mknewprot(pte));
213}
214
215static inline pte_t pte_mkuptodate(pte_t pte)
216{
217	pte_clear_bits(pte, _PAGE_NEWPAGE);
218	if(pte_present(pte))
219		pte_clear_bits(pte, _PAGE_NEWPROT);
220	return(pte);
221}
222
223static inline pte_t pte_mknewpage(pte_t pte)
224{
225	pte_set_bits(pte, _PAGE_NEWPAGE);
226	return(pte);
227}
228
229static inline void set_pte(pte_t *pteptr, pte_t pteval)
230{
231	pte_copy(*pteptr, pteval);
232
233	/* If it's a swap entry, it needs to be marked _PAGE_NEWPAGE so
234	 * fix_range knows to unmap it.  _PAGE_NEWPROT is specific to
235	 * mapped pages.
236	 */
237
238	*pteptr = pte_mknewpage(*pteptr);
239	if(pte_present(*pteptr)) *pteptr = pte_mknewprot(*pteptr);
240}
241
242static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
243			      pte_t *pteptr, pte_t pteval)
244{
245	set_pte(pteptr, pteval);
246}
247
248#define __HAVE_ARCH_PTE_SAME
249static inline int pte_same(pte_t pte_a, pte_t pte_b)
250{
251	return !((pte_val(pte_a) ^ pte_val(pte_b)) & ~_PAGE_NEWPAGE);
252}
253
254/*
255 * Conversion functions: convert a page and protection to a page entry,
256 * and a page entry and page directory to the page they refer to.
257 */
258
259#define phys_to_page(phys) pfn_to_page(phys_to_pfn(phys))
260#define __virt_to_page(virt) phys_to_page(__pa(virt))
261#define page_to_phys(page) pfn_to_phys(page_to_pfn(page))
262#define virt_to_page(addr) __virt_to_page((const unsigned long) addr)
263
264#define mk_pte(page, pgprot) \
265	({ pte_t pte;					\
266							\
267	pte_set_val(pte, page_to_phys(page), (pgprot));	\
268	if (pte_present(pte))				\
269		pte_mknewprot(pte_mknewpage(pte));	\
270	pte;})
271
272static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
273{
274	pte_set_val(pte, (pte_val(pte) & _PAGE_CHG_MASK), newprot);
275	return pte;
276}
277
278/*
279 * the pmd page can be thought of an array like this: pmd_t[PTRS_PER_PMD]
280 *
281 * this macro returns the index of the entry in the pmd page which would
282 * control the given virtual address
283 */
284#define pmd_page_vaddr(pmd) ((unsigned long) __va(pmd_val(pmd) & PAGE_MASK))
285
286struct mm_struct;
287extern pte_t *virt_to_pte(struct mm_struct *mm, unsigned long addr);
288
289#define update_mmu_cache(vma,address,ptep) do {} while (0)
290
291/* Encode and de-code a swap entry */
292#define __swp_type(x)			(((x).val >> 5) & 0x1f)
293#define __swp_offset(x)			((x).val >> 11)
294
295#define __swp_entry(type, offset) \
296	((swp_entry_t) { ((type) << 5) | ((offset) << 11) })
297#define __pte_to_swp_entry(pte) \
298	((swp_entry_t) { pte_val(pte_mkuptodate(pte)) })
299#define __swp_entry_to_pte(x)		((pte_t) { (x).val })
 
 
300
301/* Clear a kernel PTE and flush it from the TLB */
302#define kpte_clear_flush(ptep, vaddr)		\
303do {						\
304	pte_clear(&init_mm, (vaddr), (ptep));	\
305	__flush_tlb_one((vaddr));		\
306} while (0)
307
308#endif