xref: /openbmc/linux/arch/mips/include/asm/pgtable.h (revision 2d68bb26)
1 /*
2  * This file is subject to the terms and conditions of the GNU General Public
3  * License.  See the file "COPYING" in the main directory of this archive
4  * for more details.
5  *
6  * Copyright (C) 2003 Ralf Baechle
7  */
8 #ifndef _ASM_PGTABLE_H
9 #define _ASM_PGTABLE_H
10 
11 #include <linux/mm_types.h>
12 #include <linux/mmzone.h>
13 #ifdef CONFIG_32BIT
14 #include <asm/pgtable-32.h>
15 #endif
16 #ifdef CONFIG_64BIT
17 #include <asm/pgtable-64.h>
18 #endif
19 
20 #include <asm/cmpxchg.h>
21 #include <asm/io.h>
22 #include <asm/pgtable-bits.h>
23 #include <asm/cpu-features.h>
24 
25 struct mm_struct;
26 struct vm_area_struct;
27 
28 #define PAGE_NONE	__pgprot(_PAGE_PRESENT | _PAGE_NO_READ | \
29 				 _page_cachable_default)
30 #define PAGE_SHARED	__pgprot(_PAGE_PRESENT | _PAGE_WRITE | \
31 				 _page_cachable_default)
32 #define PAGE_COPY	__pgprot(_PAGE_PRESENT | _PAGE_NO_EXEC | \
33 				 _page_cachable_default)
34 #define PAGE_READONLY	__pgprot(_PAGE_PRESENT | \
35 				 _page_cachable_default)
36 #define PAGE_KERNEL	__pgprot(_PAGE_PRESENT | __READABLE | __WRITEABLE | \
37 				 _PAGE_GLOBAL | _page_cachable_default)
38 #define PAGE_KERNEL_NC	__pgprot(_PAGE_PRESENT | __READABLE | __WRITEABLE | \
39 				 _PAGE_GLOBAL | _CACHE_CACHABLE_NONCOHERENT)
40 #define PAGE_USERIO	__pgprot(_PAGE_PRESENT | _PAGE_WRITE | \
41 				 _page_cachable_default)
42 #define PAGE_KERNEL_UNCACHED __pgprot(_PAGE_PRESENT | __READABLE | \
43 			__WRITEABLE | _PAGE_GLOBAL | _CACHE_UNCACHED)
44 
45 /*
46  * If _PAGE_NO_EXEC is not defined, we can't do page protection for
47  * execute, and consider it to be the same as read. Also, write
48  * permissions imply read permissions. This is the closest we can get
49  * by reasonable means..
50  */
51 
52 /*
53  * Dummy values to fill the table in mmap.c
54  * The real values will be generated at runtime
55  */
56 #define __P000 __pgprot(0)
57 #define __P001 __pgprot(0)
58 #define __P010 __pgprot(0)
59 #define __P011 __pgprot(0)
60 #define __P100 __pgprot(0)
61 #define __P101 __pgprot(0)
62 #define __P110 __pgprot(0)
63 #define __P111 __pgprot(0)
64 
65 #define __S000 __pgprot(0)
66 #define __S001 __pgprot(0)
67 #define __S010 __pgprot(0)
68 #define __S011 __pgprot(0)
69 #define __S100 __pgprot(0)
70 #define __S101 __pgprot(0)
71 #define __S110 __pgprot(0)
72 #define __S111 __pgprot(0)
73 
74 extern unsigned long _page_cachable_default;
75 
76 /*
77  * ZERO_PAGE is a global shared page that is always zero; used
78  * for zero-mapped memory areas etc..
79  */
80 
81 extern unsigned long empty_zero_page;
82 extern unsigned long zero_page_mask;
83 
84 #define ZERO_PAGE(vaddr) \
85 	(virt_to_page((void *)(empty_zero_page + (((unsigned long)(vaddr)) & zero_page_mask))))
86 #define __HAVE_COLOR_ZERO_PAGE
87 
88 extern void paging_init(void);
89 
90 /*
91  * Conversion functions: convert a page and protection to a page entry,
92  * and a page entry and page directory to the page they refer to.
93  */
94 #define pmd_phys(pmd)		virt_to_phys((void *)pmd_val(pmd))
95 
96 #define __pmd_page(pmd)		(pfn_to_page(pmd_phys(pmd) >> PAGE_SHIFT))
97 #ifndef CONFIG_TRANSPARENT_HUGEPAGE
98 #define pmd_page(pmd)		__pmd_page(pmd)
99 #endif /* CONFIG_TRANSPARENT_HUGEPAGE  */
100 
101 #define pmd_page_vaddr(pmd)	pmd_val(pmd)
102 
103 #define htw_stop()							\
104 do {									\
105 	unsigned long flags;						\
106 									\
107 	if (cpu_has_htw) {						\
108 		local_irq_save(flags);					\
109 		if(!raw_current_cpu_data.htw_seq++) {			\
110 			write_c0_pwctl(read_c0_pwctl() &		\
111 				       ~(1 << MIPS_PWCTL_PWEN_SHIFT));	\
112 			back_to_back_c0_hazard();			\
113 		}							\
114 		local_irq_restore(flags);				\
115 	}								\
116 } while(0)
117 
118 #define htw_start()							\
119 do {									\
120 	unsigned long flags;						\
121 									\
122 	if (cpu_has_htw) {						\
123 		local_irq_save(flags);					\
124 		if (!--raw_current_cpu_data.htw_seq) {			\
125 			write_c0_pwctl(read_c0_pwctl() |		\
126 				       (1 << MIPS_PWCTL_PWEN_SHIFT));	\
127 			back_to_back_c0_hazard();			\
128 		}							\
129 		local_irq_restore(flags);				\
130 	}								\
131 } while(0)
132 
133 static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
134 			      pte_t *ptep, pte_t pteval);
135 
136 #if defined(CONFIG_PHYS_ADDR_T_64BIT) && defined(CONFIG_CPU_MIPS32)
137 
138 #ifdef CONFIG_XPA
139 # define pte_none(pte)		(!(((pte).pte_high) & ~_PAGE_GLOBAL))
140 #else
141 # define pte_none(pte)		(!(((pte).pte_low | (pte).pte_high) & ~_PAGE_GLOBAL))
142 #endif
143 
144 #define pte_present(pte)	((pte).pte_low & _PAGE_PRESENT)
145 #define pte_no_exec(pte)	((pte).pte_low & _PAGE_NO_EXEC)
146 
147 static inline void set_pte(pte_t *ptep, pte_t pte)
148 {
149 	ptep->pte_high = pte.pte_high;
150 	smp_wmb();
151 	ptep->pte_low = pte.pte_low;
152 
153 #ifdef CONFIG_XPA
154 	if (pte.pte_high & _PAGE_GLOBAL) {
155 #else
156 	if (pte.pte_low & _PAGE_GLOBAL) {
157 #endif
158 		pte_t *buddy = ptep_buddy(ptep);
159 		/*
160 		 * Make sure the buddy is global too (if it's !none,
161 		 * it better already be global)
162 		 */
163 		if (pte_none(*buddy)) {
164 			if (!IS_ENABLED(CONFIG_XPA))
165 				buddy->pte_low |= _PAGE_GLOBAL;
166 			buddy->pte_high |= _PAGE_GLOBAL;
167 		}
168 	}
169 }
170 
171 static inline void pte_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
172 {
173 	pte_t null = __pte(0);
174 
175 	htw_stop();
176 	/* Preserve global status for the pair */
177 	if (IS_ENABLED(CONFIG_XPA)) {
178 		if (ptep_buddy(ptep)->pte_high & _PAGE_GLOBAL)
179 			null.pte_high = _PAGE_GLOBAL;
180 	} else {
181 		if (ptep_buddy(ptep)->pte_low & _PAGE_GLOBAL)
182 			null.pte_low = null.pte_high = _PAGE_GLOBAL;
183 	}
184 
185 	set_pte_at(mm, addr, ptep, null);
186 	htw_start();
187 }
188 #else
189 
190 #define pte_none(pte)		(!(pte_val(pte) & ~_PAGE_GLOBAL))
191 #define pte_present(pte)	(pte_val(pte) & _PAGE_PRESENT)
192 #define pte_no_exec(pte)	(pte_val(pte) & _PAGE_NO_EXEC)
193 
194 /*
195  * Certain architectures need to do special things when pte's
196  * within a page table are directly modified.  Thus, the following
197  * hook is made available.
198  */
199 static inline void set_pte(pte_t *ptep, pte_t pteval)
200 {
201 	*ptep = pteval;
202 #if !defined(CONFIG_CPU_R3K_TLB)
203 	if (pte_val(pteval) & _PAGE_GLOBAL) {
204 		pte_t *buddy = ptep_buddy(ptep);
205 		/*
206 		 * Make sure the buddy is global too (if it's !none,
207 		 * it better already be global)
208 		 */
209 # if defined(CONFIG_PHYS_ADDR_T_64BIT) && !defined(CONFIG_CPU_MIPS32)
210 		cmpxchg64(&buddy->pte, 0, _PAGE_GLOBAL);
211 # else
212 		cmpxchg(&buddy->pte, 0, _PAGE_GLOBAL);
213 # endif
214 	}
215 #endif
216 }
217 
218 static inline void pte_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
219 {
220 	htw_stop();
221 #if !defined(CONFIG_CPU_R3K_TLB)
222 	/* Preserve global status for the pair */
223 	if (pte_val(*ptep_buddy(ptep)) & _PAGE_GLOBAL)
224 		set_pte_at(mm, addr, ptep, __pte(_PAGE_GLOBAL));
225 	else
226 #endif
227 		set_pte_at(mm, addr, ptep, __pte(0));
228 	htw_start();
229 }
230 #endif
231 
232 static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
233 			      pte_t *ptep, pte_t pteval)
234 {
235 	extern void __update_cache(unsigned long address, pte_t pte);
236 
237 	if (!pte_present(pteval))
238 		goto cache_sync_done;
239 
240 	if (pte_present(*ptep) && (pte_pfn(*ptep) == pte_pfn(pteval)))
241 		goto cache_sync_done;
242 
243 	__update_cache(addr, pteval);
244 cache_sync_done:
245 	set_pte(ptep, pteval);
246 }
247 
248 /*
249  * (pmds are folded into puds so this doesn't get actually called,
250  * but the define is needed for a generic inline function.)
251  */
252 #define set_pmd(pmdptr, pmdval) do { *(pmdptr) = (pmdval); } while(0)
253 
254 #ifndef __PAGETABLE_PMD_FOLDED
255 /*
256  * (puds are folded into pgds so this doesn't get actually called,
257  * but the define is needed for a generic inline function.)
258  */
259 #define set_pud(pudptr, pudval) do { *(pudptr) = (pudval); } while(0)
260 #endif
261 
262 #define PGD_T_LOG2	(__builtin_ffs(sizeof(pgd_t)) - 1)
263 #define PMD_T_LOG2	(__builtin_ffs(sizeof(pmd_t)) - 1)
264 #define PTE_T_LOG2	(__builtin_ffs(sizeof(pte_t)) - 1)
265 
266 /*
267  * We used to declare this array with size but gcc 3.3 and older are not able
268  * to find that this expression is a constant, so the size is dropped.
269  */
270 extern pgd_t swapper_pg_dir[];
271 
272 /*
273  * The following only work if pte_present() is true.
274  * Undefined behaviour if not..
275  */
276 #if defined(CONFIG_PHYS_ADDR_T_64BIT) && defined(CONFIG_CPU_MIPS32)
277 static inline int pte_write(pte_t pte)	{ return pte.pte_low & _PAGE_WRITE; }
278 static inline int pte_dirty(pte_t pte)	{ return pte.pte_low & _PAGE_MODIFIED; }
279 static inline int pte_young(pte_t pte)	{ return pte.pte_low & _PAGE_ACCESSED; }
280 static inline int pte_special(pte_t pte) { return pte.pte_low & _PAGE_SPECIAL; }
281 
282 static inline pte_t pte_wrprotect(pte_t pte)
283 {
284 	pte.pte_low  &= ~_PAGE_WRITE;
285 	if (!IS_ENABLED(CONFIG_XPA))
286 		pte.pte_low &= ~_PAGE_SILENT_WRITE;
287 	pte.pte_high &= ~_PAGE_SILENT_WRITE;
288 	return pte;
289 }
290 
291 static inline pte_t pte_mkclean(pte_t pte)
292 {
293 	pte.pte_low  &= ~_PAGE_MODIFIED;
294 	if (!IS_ENABLED(CONFIG_XPA))
295 		pte.pte_low &= ~_PAGE_SILENT_WRITE;
296 	pte.pte_high &= ~_PAGE_SILENT_WRITE;
297 	return pte;
298 }
299 
300 static inline pte_t pte_mkold(pte_t pte)
301 {
302 	pte.pte_low  &= ~_PAGE_ACCESSED;
303 	if (!IS_ENABLED(CONFIG_XPA))
304 		pte.pte_low &= ~_PAGE_SILENT_READ;
305 	pte.pte_high &= ~_PAGE_SILENT_READ;
306 	return pte;
307 }
308 
309 static inline pte_t pte_mkwrite(pte_t pte)
310 {
311 	pte.pte_low |= _PAGE_WRITE;
312 	if (pte.pte_low & _PAGE_MODIFIED) {
313 		if (!IS_ENABLED(CONFIG_XPA))
314 			pte.pte_low |= _PAGE_SILENT_WRITE;
315 		pte.pte_high |= _PAGE_SILENT_WRITE;
316 	}
317 	return pte;
318 }
319 
320 static inline pte_t pte_mkdirty(pte_t pte)
321 {
322 	pte.pte_low |= _PAGE_MODIFIED;
323 	if (pte.pte_low & _PAGE_WRITE) {
324 		if (!IS_ENABLED(CONFIG_XPA))
325 			pte.pte_low |= _PAGE_SILENT_WRITE;
326 		pte.pte_high |= _PAGE_SILENT_WRITE;
327 	}
328 	return pte;
329 }
330 
331 static inline pte_t pte_mkyoung(pte_t pte)
332 {
333 	pte.pte_low |= _PAGE_ACCESSED;
334 	if (!(pte.pte_low & _PAGE_NO_READ)) {
335 		if (!IS_ENABLED(CONFIG_XPA))
336 			pte.pte_low |= _PAGE_SILENT_READ;
337 		pte.pte_high |= _PAGE_SILENT_READ;
338 	}
339 	return pte;
340 }
341 
342 static inline pte_t pte_mkspecial(pte_t pte)
343 {
344 	pte.pte_low |= _PAGE_SPECIAL;
345 	return pte;
346 }
347 #else
348 static inline int pte_write(pte_t pte)	{ return pte_val(pte) & _PAGE_WRITE; }
349 static inline int pte_dirty(pte_t pte)	{ return pte_val(pte) & _PAGE_MODIFIED; }
350 static inline int pte_young(pte_t pte)	{ return pte_val(pte) & _PAGE_ACCESSED; }
351 static inline int pte_special(pte_t pte) { return pte_val(pte) & _PAGE_SPECIAL; }
352 
353 static inline pte_t pte_wrprotect(pte_t pte)
354 {
355 	pte_val(pte) &= ~(_PAGE_WRITE | _PAGE_SILENT_WRITE);
356 	return pte;
357 }
358 
359 static inline pte_t pte_mkclean(pte_t pte)
360 {
361 	pte_val(pte) &= ~(_PAGE_MODIFIED | _PAGE_SILENT_WRITE);
362 	return pte;
363 }
364 
365 static inline pte_t pte_mkold(pte_t pte)
366 {
367 	pte_val(pte) &= ~(_PAGE_ACCESSED | _PAGE_SILENT_READ);
368 	return pte;
369 }
370 
371 static inline pte_t pte_mkwrite(pte_t pte)
372 {
373 	pte_val(pte) |= _PAGE_WRITE;
374 	if (pte_val(pte) & _PAGE_MODIFIED)
375 		pte_val(pte) |= _PAGE_SILENT_WRITE;
376 	return pte;
377 }
378 
379 static inline pte_t pte_mkdirty(pte_t pte)
380 {
381 	pte_val(pte) |= _PAGE_MODIFIED;
382 	if (pte_val(pte) & _PAGE_WRITE)
383 		pte_val(pte) |= _PAGE_SILENT_WRITE;
384 	return pte;
385 }
386 
387 static inline pte_t pte_mkyoung(pte_t pte)
388 {
389 	pte_val(pte) |= _PAGE_ACCESSED;
390 	if (!(pte_val(pte) & _PAGE_NO_READ))
391 		pte_val(pte) |= _PAGE_SILENT_READ;
392 	return pte;
393 }
394 
395 static inline pte_t pte_mkspecial(pte_t pte)
396 {
397 	pte_val(pte) |= _PAGE_SPECIAL;
398 	return pte;
399 }
400 
401 #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
402 static inline int pte_huge(pte_t pte)	{ return pte_val(pte) & _PAGE_HUGE; }
403 
404 static inline pte_t pte_mkhuge(pte_t pte)
405 {
406 	pte_val(pte) |= _PAGE_HUGE;
407 	return pte;
408 }
409 #endif /* CONFIG_MIPS_HUGE_TLB_SUPPORT */
410 #endif
411 
412 /*
413  * Macro to make mark a page protection value as "uncacheable".	 Note
414  * that "protection" is really a misnomer here as the protection value
415  * contains the memory attribute bits, dirty bits, and various other
416  * bits as well.
417  */
418 #define pgprot_noncached pgprot_noncached
419 
420 static inline pgprot_t pgprot_noncached(pgprot_t _prot)
421 {
422 	unsigned long prot = pgprot_val(_prot);
423 
424 	prot = (prot & ~_CACHE_MASK) | _CACHE_UNCACHED;
425 
426 	return __pgprot(prot);
427 }
428 
429 #define pgprot_writecombine pgprot_writecombine
430 
431 static inline pgprot_t pgprot_writecombine(pgprot_t _prot)
432 {
433 	unsigned long prot = pgprot_val(_prot);
434 
435 	/* cpu_data[0].writecombine is already shifted by _CACHE_SHIFT */
436 	prot = (prot & ~_CACHE_MASK) | cpu_data[0].writecombine;
437 
438 	return __pgprot(prot);
439 }
440 
441 /*
442  * Conversion functions: convert a page and protection to a page entry,
443  * and a page entry and page directory to the page they refer to.
444  */
445 #define mk_pte(page, pgprot)	pfn_pte(page_to_pfn(page), (pgprot))
446 
447 #if defined(CONFIG_XPA)
448 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
449 {
450 	pte.pte_low  &= (_PAGE_MODIFIED | _PAGE_ACCESSED | _PFNX_MASK);
451 	pte.pte_high &= (_PFN_MASK | _CACHE_MASK);
452 	pte.pte_low  |= pgprot_val(newprot) & ~_PFNX_MASK;
453 	pte.pte_high |= pgprot_val(newprot) & ~(_PFN_MASK | _CACHE_MASK);
454 	return pte;
455 }
456 #elif defined(CONFIG_PHYS_ADDR_T_64BIT) && defined(CONFIG_CPU_MIPS32)
457 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
458 {
459 	pte.pte_low  &= _PAGE_CHG_MASK;
460 	pte.pte_high &= (_PFN_MASK | _CACHE_MASK);
461 	pte.pte_low  |= pgprot_val(newprot);
462 	pte.pte_high |= pgprot_val(newprot) & ~(_PFN_MASK | _CACHE_MASK);
463 	return pte;
464 }
465 #else
466 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
467 {
468 	return __pte((pte_val(pte) & _PAGE_CHG_MASK) |
469 		     (pgprot_val(newprot) & ~_PAGE_CHG_MASK));
470 }
471 #endif
472 
473 
474 extern void __update_tlb(struct vm_area_struct *vma, unsigned long address,
475 	pte_t pte);
476 
477 static inline void update_mmu_cache(struct vm_area_struct *vma,
478 	unsigned long address, pte_t *ptep)
479 {
480 	pte_t pte = *ptep;
481 	__update_tlb(vma, address, pte);
482 }
483 
484 static inline void update_mmu_cache_pmd(struct vm_area_struct *vma,
485 	unsigned long address, pmd_t *pmdp)
486 {
487 	pte_t pte = *(pte_t *)pmdp;
488 
489 	__update_tlb(vma, address, pte);
490 }
491 
492 #define kern_addr_valid(addr)	(1)
493 
494 #ifdef CONFIG_PHYS_ADDR_T_64BIT
495 extern int remap_pfn_range(struct vm_area_struct *vma, unsigned long from, unsigned long pfn, unsigned long size, pgprot_t prot);
496 
497 static inline int io_remap_pfn_range(struct vm_area_struct *vma,
498 		unsigned long vaddr,
499 		unsigned long pfn,
500 		unsigned long size,
501 		pgprot_t prot)
502 {
503 	phys_addr_t phys_addr_high = fixup_bigphys_addr(pfn << PAGE_SHIFT, size);
504 	return remap_pfn_range(vma, vaddr, phys_addr_high >> PAGE_SHIFT, size, prot);
505 }
506 #define io_remap_pfn_range io_remap_pfn_range
507 #endif
508 
509 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
510 
511 /* We don't have hardware dirty/accessed bits, generic_pmdp_establish is fine.*/
512 #define pmdp_establish generic_pmdp_establish
513 
514 #define has_transparent_hugepage has_transparent_hugepage
515 extern int has_transparent_hugepage(void);
516 
517 static inline int pmd_trans_huge(pmd_t pmd)
518 {
519 	return !!(pmd_val(pmd) & _PAGE_HUGE);
520 }
521 
522 static inline pmd_t pmd_mkhuge(pmd_t pmd)
523 {
524 	pmd_val(pmd) |= _PAGE_HUGE;
525 
526 	return pmd;
527 }
528 
529 extern void set_pmd_at(struct mm_struct *mm, unsigned long addr,
530 		       pmd_t *pmdp, pmd_t pmd);
531 
532 #define pmd_write pmd_write
533 static inline int pmd_write(pmd_t pmd)
534 {
535 	return !!(pmd_val(pmd) & _PAGE_WRITE);
536 }
537 
538 static inline pmd_t pmd_wrprotect(pmd_t pmd)
539 {
540 	pmd_val(pmd) &= ~(_PAGE_WRITE | _PAGE_SILENT_WRITE);
541 	return pmd;
542 }
543 
544 static inline pmd_t pmd_mkwrite(pmd_t pmd)
545 {
546 	pmd_val(pmd) |= _PAGE_WRITE;
547 	if (pmd_val(pmd) & _PAGE_MODIFIED)
548 		pmd_val(pmd) |= _PAGE_SILENT_WRITE;
549 
550 	return pmd;
551 }
552 
553 static inline int pmd_dirty(pmd_t pmd)
554 {
555 	return !!(pmd_val(pmd) & _PAGE_MODIFIED);
556 }
557 
558 static inline pmd_t pmd_mkclean(pmd_t pmd)
559 {
560 	pmd_val(pmd) &= ~(_PAGE_MODIFIED | _PAGE_SILENT_WRITE);
561 	return pmd;
562 }
563 
564 static inline pmd_t pmd_mkdirty(pmd_t pmd)
565 {
566 	pmd_val(pmd) |= _PAGE_MODIFIED;
567 	if (pmd_val(pmd) & _PAGE_WRITE)
568 		pmd_val(pmd) |= _PAGE_SILENT_WRITE;
569 
570 	return pmd;
571 }
572 
573 static inline int pmd_young(pmd_t pmd)
574 {
575 	return !!(pmd_val(pmd) & _PAGE_ACCESSED);
576 }
577 
578 static inline pmd_t pmd_mkold(pmd_t pmd)
579 {
580 	pmd_val(pmd) &= ~(_PAGE_ACCESSED|_PAGE_SILENT_READ);
581 
582 	return pmd;
583 }
584 
585 static inline pmd_t pmd_mkyoung(pmd_t pmd)
586 {
587 	pmd_val(pmd) |= _PAGE_ACCESSED;
588 
589 	if (!(pmd_val(pmd) & _PAGE_NO_READ))
590 		pmd_val(pmd) |= _PAGE_SILENT_READ;
591 
592 	return pmd;
593 }
594 
595 /* Extern to avoid header file madness */
596 extern pmd_t mk_pmd(struct page *page, pgprot_t prot);
597 
598 static inline unsigned long pmd_pfn(pmd_t pmd)
599 {
600 	return pmd_val(pmd) >> _PFN_SHIFT;
601 }
602 
603 static inline struct page *pmd_page(pmd_t pmd)
604 {
605 	if (pmd_trans_huge(pmd))
606 		return pfn_to_page(pmd_pfn(pmd));
607 
608 	return pfn_to_page(pmd_phys(pmd) >> PAGE_SHIFT);
609 }
610 
611 static inline pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot)
612 {
613 	pmd_val(pmd) = (pmd_val(pmd) & (_PAGE_CHG_MASK | _PAGE_HUGE)) |
614 		       (pgprot_val(newprot) & ~_PAGE_CHG_MASK);
615 	return pmd;
616 }
617 
618 static inline pmd_t pmd_mknotpresent(pmd_t pmd)
619 {
620 	pmd_val(pmd) &= ~(_PAGE_PRESENT | _PAGE_VALID | _PAGE_DIRTY);
621 
622 	return pmd;
623 }
624 
625 /*
626  * The generic version pmdp_huge_get_and_clear uses a version of pmd_clear() with a
627  * different prototype.
628  */
629 #define __HAVE_ARCH_PMDP_HUGE_GET_AND_CLEAR
630 static inline pmd_t pmdp_huge_get_and_clear(struct mm_struct *mm,
631 					    unsigned long address, pmd_t *pmdp)
632 {
633 	pmd_t old = *pmdp;
634 
635 	pmd_clear(pmdp);
636 
637 	return old;
638 }
639 
640 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
641 
642 #define gup_fast_permitted(start, end)	(!cpu_has_dc_aliases)
643 
644 #include <asm-generic/pgtable.h>
645 
646 /*
647  * We provide our own get_unmapped area to cope with the virtual aliasing
648  * constraints placed on us by the cache architecture.
649  */
650 #define HAVE_ARCH_UNMAPPED_AREA
651 #define HAVE_ARCH_UNMAPPED_AREA_TOPDOWN
652 
653 #endif /* _ASM_PGTABLE_H */
654