xref: /openbmc/linux/arch/mips/include/asm/pgtable.h (revision 92a2c6b2)
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/io.h>
21 #include <asm/pgtable-bits.h>
22 
23 struct mm_struct;
24 struct vm_area_struct;
25 
26 #define PAGE_NONE	__pgprot(_PAGE_PRESENT | _CACHE_CACHABLE_NONCOHERENT)
27 #define PAGE_SHARED	__pgprot(_PAGE_PRESENT | _PAGE_WRITE | (cpu_has_rixi ? 0 : _PAGE_READ) | \
28 				 _page_cachable_default)
29 #define PAGE_COPY	__pgprot(_PAGE_PRESENT | (cpu_has_rixi ? 0 : _PAGE_READ) | \
30 				 (cpu_has_rixi ?  _PAGE_NO_EXEC : 0) | _page_cachable_default)
31 #define PAGE_READONLY	__pgprot(_PAGE_PRESENT | (cpu_has_rixi ? 0 : _PAGE_READ) | \
32 				 _page_cachable_default)
33 #define PAGE_KERNEL	__pgprot(_PAGE_PRESENT | __READABLE | __WRITEABLE | \
34 				 _PAGE_GLOBAL | _page_cachable_default)
35 #define PAGE_KERNEL_NC	__pgprot(_PAGE_PRESENT | __READABLE | __WRITEABLE | \
36 				 _PAGE_GLOBAL | _CACHE_CACHABLE_NONCOHERENT)
37 #define PAGE_USERIO	__pgprot(_PAGE_PRESENT | (cpu_has_rixi ? 0 : _PAGE_READ) | _PAGE_WRITE | \
38 				 _page_cachable_default)
39 #define PAGE_KERNEL_UNCACHED __pgprot(_PAGE_PRESENT | __READABLE | \
40 			__WRITEABLE | _PAGE_GLOBAL | _CACHE_UNCACHED)
41 
42 /*
43  * If _PAGE_NO_EXEC is not defined, we can't do page protection for
44  * execute, and consider it to be the same as read. Also, write
45  * permissions imply read permissions. This is the closest we can get
46  * by reasonable means..
47  */
48 
49 /*
50  * Dummy values to fill the table in mmap.c
51  * The real values will be generated at runtime
52  */
53 #define __P000 __pgprot(0)
54 #define __P001 __pgprot(0)
55 #define __P010 __pgprot(0)
56 #define __P011 __pgprot(0)
57 #define __P100 __pgprot(0)
58 #define __P101 __pgprot(0)
59 #define __P110 __pgprot(0)
60 #define __P111 __pgprot(0)
61 
62 #define __S000 __pgprot(0)
63 #define __S001 __pgprot(0)
64 #define __S010 __pgprot(0)
65 #define __S011 __pgprot(0)
66 #define __S100 __pgprot(0)
67 #define __S101 __pgprot(0)
68 #define __S110 __pgprot(0)
69 #define __S111 __pgprot(0)
70 
71 extern unsigned long _page_cachable_default;
72 
73 /*
74  * ZERO_PAGE is a global shared page that is always zero; used
75  * for zero-mapped memory areas etc..
76  */
77 
78 extern unsigned long empty_zero_page;
79 extern unsigned long zero_page_mask;
80 
81 #define ZERO_PAGE(vaddr) \
82 	(virt_to_page((void *)(empty_zero_page + (((unsigned long)(vaddr)) & zero_page_mask))))
83 #define __HAVE_COLOR_ZERO_PAGE
84 
85 extern void paging_init(void);
86 
87 /*
88  * Conversion functions: convert a page and protection to a page entry,
89  * and a page entry and page directory to the page they refer to.
90  */
91 #define pmd_phys(pmd)		virt_to_phys((void *)pmd_val(pmd))
92 
93 #define __pmd_page(pmd)		(pfn_to_page(pmd_phys(pmd) >> PAGE_SHIFT))
94 #ifndef CONFIG_TRANSPARENT_HUGEPAGE
95 #define pmd_page(pmd)		__pmd_page(pmd)
96 #endif /* CONFIG_TRANSPARENT_HUGEPAGE  */
97 
98 #define pmd_page_vaddr(pmd)	pmd_val(pmd)
99 
100 #define htw_stop()							\
101 do {									\
102 	unsigned long flags;						\
103 									\
104 	if (cpu_has_htw) {						\
105 		local_irq_save(flags);					\
106 		if(!raw_current_cpu_data.htw_seq++) {			\
107 			write_c0_pwctl(read_c0_pwctl() &		\
108 				       ~(1 << MIPS_PWCTL_PWEN_SHIFT));	\
109 			back_to_back_c0_hazard();			\
110 		}							\
111 		local_irq_restore(flags);				\
112 	}								\
113 } while(0)
114 
115 #define htw_start()							\
116 do {									\
117 	unsigned long flags;						\
118 									\
119 	if (cpu_has_htw) {						\
120 		local_irq_save(flags);					\
121 		if (!--raw_current_cpu_data.htw_seq) {			\
122 			write_c0_pwctl(read_c0_pwctl() |		\
123 				       (1 << MIPS_PWCTL_PWEN_SHIFT));	\
124 			back_to_back_c0_hazard();			\
125 		}							\
126 		local_irq_restore(flags);				\
127 	}								\
128 } while(0)
129 
130 
131 extern void set_pte_at(struct mm_struct *mm, unsigned long addr, pte_t *ptep,
132 	pte_t pteval);
133 
134 #if defined(CONFIG_PHYS_ADDR_T_64BIT) && defined(CONFIG_CPU_MIPS32)
135 
136 #define pte_none(pte)		(!(((pte).pte_low | (pte).pte_high) & ~_PAGE_GLOBAL))
137 #define pte_present(pte)	((pte).pte_low & _PAGE_PRESENT)
138 
139 static inline void set_pte(pte_t *ptep, pte_t pte)
140 {
141 	ptep->pte_high = pte.pte_high;
142 	smp_wmb();
143 	ptep->pte_low = pte.pte_low;
144 
145 	if (pte.pte_low & _PAGE_GLOBAL) {
146 		pte_t *buddy = ptep_buddy(ptep);
147 		/*
148 		 * Make sure the buddy is global too (if it's !none,
149 		 * it better already be global)
150 		 */
151 		if (pte_none(*buddy)) {
152 			buddy->pte_low	|= _PAGE_GLOBAL;
153 			buddy->pte_high |= _PAGE_GLOBAL;
154 		}
155 	}
156 }
157 
158 static inline void pte_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
159 {
160 	pte_t null = __pte(0);
161 
162 	htw_stop();
163 	/* Preserve global status for the pair */
164 	if (ptep_buddy(ptep)->pte_low & _PAGE_GLOBAL)
165 		null.pte_low = null.pte_high = _PAGE_GLOBAL;
166 
167 	set_pte_at(mm, addr, ptep, null);
168 	htw_start();
169 }
170 #else
171 
172 #define pte_none(pte)		(!(pte_val(pte) & ~_PAGE_GLOBAL))
173 #define pte_present(pte)	(pte_val(pte) & _PAGE_PRESENT)
174 
175 /*
176  * Certain architectures need to do special things when pte's
177  * within a page table are directly modified.  Thus, the following
178  * hook is made available.
179  */
180 static inline void set_pte(pte_t *ptep, pte_t pteval)
181 {
182 	*ptep = pteval;
183 #if !defined(CONFIG_CPU_R3000) && !defined(CONFIG_CPU_TX39XX)
184 	if (pte_val(pteval) & _PAGE_GLOBAL) {
185 		pte_t *buddy = ptep_buddy(ptep);
186 		/*
187 		 * Make sure the buddy is global too (if it's !none,
188 		 * it better already be global)
189 		 */
190 		if (pte_none(*buddy))
191 			pte_val(*buddy) = pte_val(*buddy) | _PAGE_GLOBAL;
192 	}
193 #endif
194 }
195 
196 static inline void pte_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
197 {
198 	htw_stop();
199 #if !defined(CONFIG_CPU_R3000) && !defined(CONFIG_CPU_TX39XX)
200 	/* Preserve global status for the pair */
201 	if (pte_val(*ptep_buddy(ptep)) & _PAGE_GLOBAL)
202 		set_pte_at(mm, addr, ptep, __pte(_PAGE_GLOBAL));
203 	else
204 #endif
205 		set_pte_at(mm, addr, ptep, __pte(0));
206 	htw_start();
207 }
208 #endif
209 
210 /*
211  * (pmds are folded into puds so this doesn't get actually called,
212  * but the define is needed for a generic inline function.)
213  */
214 #define set_pmd(pmdptr, pmdval) do { *(pmdptr) = (pmdval); } while(0)
215 
216 #ifndef __PAGETABLE_PMD_FOLDED
217 /*
218  * (puds are folded into pgds so this doesn't get actually called,
219  * but the define is needed for a generic inline function.)
220  */
221 #define set_pud(pudptr, pudval) do { *(pudptr) = (pudval); } while(0)
222 #endif
223 
224 #define PGD_T_LOG2	(__builtin_ffs(sizeof(pgd_t)) - 1)
225 #define PMD_T_LOG2	(__builtin_ffs(sizeof(pmd_t)) - 1)
226 #define PTE_T_LOG2	(__builtin_ffs(sizeof(pte_t)) - 1)
227 
228 /*
229  * We used to declare this array with size but gcc 3.3 and older are not able
230  * to find that this expression is a constant, so the size is dropped.
231  */
232 extern pgd_t swapper_pg_dir[];
233 
234 /*
235  * The following only work if pte_present() is true.
236  * Undefined behaviour if not..
237  */
238 #if defined(CONFIG_PHYS_ADDR_T_64BIT) && defined(CONFIG_CPU_MIPS32)
239 static inline int pte_write(pte_t pte)	{ return pte.pte_low & _PAGE_WRITE; }
240 static inline int pte_dirty(pte_t pte)	{ return pte.pte_low & _PAGE_MODIFIED; }
241 static inline int pte_young(pte_t pte)	{ return pte.pte_low & _PAGE_ACCESSED; }
242 
243 static inline pte_t pte_wrprotect(pte_t pte)
244 {
245 	pte.pte_low  &= ~(_PAGE_WRITE | _PAGE_SILENT_WRITE);
246 	pte.pte_high &= ~_PAGE_SILENT_WRITE;
247 	return pte;
248 }
249 
250 static inline pte_t pte_mkclean(pte_t pte)
251 {
252 	pte.pte_low  &= ~(_PAGE_MODIFIED | _PAGE_SILENT_WRITE);
253 	pte.pte_high &= ~_PAGE_SILENT_WRITE;
254 	return pte;
255 }
256 
257 static inline pte_t pte_mkold(pte_t pte)
258 {
259 	pte.pte_low  &= ~(_PAGE_ACCESSED | _PAGE_SILENT_READ);
260 	pte.pte_high &= ~_PAGE_SILENT_READ;
261 	return pte;
262 }
263 
264 static inline pte_t pte_mkwrite(pte_t pte)
265 {
266 	pte.pte_low |= _PAGE_WRITE;
267 	if (pte.pte_low & _PAGE_MODIFIED) {
268 		pte.pte_low  |= _PAGE_SILENT_WRITE;
269 		pte.pte_high |= _PAGE_SILENT_WRITE;
270 	}
271 	return pte;
272 }
273 
274 static inline pte_t pte_mkdirty(pte_t pte)
275 {
276 	pte.pte_low |= _PAGE_MODIFIED;
277 	if (pte.pte_low & _PAGE_WRITE) {
278 		pte.pte_low  |= _PAGE_SILENT_WRITE;
279 		pte.pte_high |= _PAGE_SILENT_WRITE;
280 	}
281 	return pte;
282 }
283 
284 static inline pte_t pte_mkyoung(pte_t pte)
285 {
286 	pte.pte_low |= _PAGE_ACCESSED;
287 	if (pte.pte_low & _PAGE_READ) {
288 		pte.pte_low  |= _PAGE_SILENT_READ;
289 		pte.pte_high |= _PAGE_SILENT_READ;
290 	}
291 	return pte;
292 }
293 #else
294 static inline int pte_write(pte_t pte)	{ return pte_val(pte) & _PAGE_WRITE; }
295 static inline int pte_dirty(pte_t pte)	{ return pte_val(pte) & _PAGE_MODIFIED; }
296 static inline int pte_young(pte_t pte)	{ return pte_val(pte) & _PAGE_ACCESSED; }
297 
298 static inline pte_t pte_wrprotect(pte_t pte)
299 {
300 	pte_val(pte) &= ~(_PAGE_WRITE | _PAGE_SILENT_WRITE);
301 	return pte;
302 }
303 
304 static inline pte_t pte_mkclean(pte_t pte)
305 {
306 	pte_val(pte) &= ~(_PAGE_MODIFIED | _PAGE_SILENT_WRITE);
307 	return pte;
308 }
309 
310 static inline pte_t pte_mkold(pte_t pte)
311 {
312 	pte_val(pte) &= ~(_PAGE_ACCESSED | _PAGE_SILENT_READ);
313 	return pte;
314 }
315 
316 static inline pte_t pte_mkwrite(pte_t pte)
317 {
318 	pte_val(pte) |= _PAGE_WRITE;
319 	if (pte_val(pte) & _PAGE_MODIFIED)
320 		pte_val(pte) |= _PAGE_SILENT_WRITE;
321 	return pte;
322 }
323 
324 static inline pte_t pte_mkdirty(pte_t pte)
325 {
326 	pte_val(pte) |= _PAGE_MODIFIED;
327 	if (pte_val(pte) & _PAGE_WRITE)
328 		pte_val(pte) |= _PAGE_SILENT_WRITE;
329 	return pte;
330 }
331 
332 static inline pte_t pte_mkyoung(pte_t pte)
333 {
334 	pte_val(pte) |= _PAGE_ACCESSED;
335 	if (cpu_has_rixi) {
336 		if (!(pte_val(pte) & _PAGE_NO_READ))
337 			pte_val(pte) |= _PAGE_SILENT_READ;
338 	} else {
339 		if (pte_val(pte) & _PAGE_READ)
340 			pte_val(pte) |= _PAGE_SILENT_READ;
341 	}
342 	return pte;
343 }
344 
345 #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
346 static inline int pte_huge(pte_t pte)	{ return pte_val(pte) & _PAGE_HUGE; }
347 
348 static inline pte_t pte_mkhuge(pte_t pte)
349 {
350 	pte_val(pte) |= _PAGE_HUGE;
351 	return pte;
352 }
353 #endif /* CONFIG_MIPS_HUGE_TLB_SUPPORT */
354 #endif
355 static inline int pte_special(pte_t pte)	{ return 0; }
356 static inline pte_t pte_mkspecial(pte_t pte)	{ return pte; }
357 
358 /*
359  * Macro to make mark a page protection value as "uncacheable".	 Note
360  * that "protection" is really a misnomer here as the protection value
361  * contains the memory attribute bits, dirty bits, and various other
362  * bits as well.
363  */
364 #define pgprot_noncached pgprot_noncached
365 
366 static inline pgprot_t pgprot_noncached(pgprot_t _prot)
367 {
368 	unsigned long prot = pgprot_val(_prot);
369 
370 	prot = (prot & ~_CACHE_MASK) | _CACHE_UNCACHED;
371 
372 	return __pgprot(prot);
373 }
374 
375 static inline pgprot_t pgprot_writecombine(pgprot_t _prot)
376 {
377 	unsigned long prot = pgprot_val(_prot);
378 
379 	/* cpu_data[0].writecombine is already shifted by _CACHE_SHIFT */
380 	prot = (prot & ~_CACHE_MASK) | cpu_data[0].writecombine;
381 
382 	return __pgprot(prot);
383 }
384 
385 /*
386  * Conversion functions: convert a page and protection to a page entry,
387  * and a page entry and page directory to the page they refer to.
388  */
389 #define mk_pte(page, pgprot)	pfn_pte(page_to_pfn(page), (pgprot))
390 
391 #if defined(CONFIG_PHYS_ADDR_T_64BIT) && defined(CONFIG_CPU_MIPS32)
392 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
393 {
394 	pte.pte_low  &= _PAGE_CHG_MASK;
395 	pte.pte_high &= (_PFN_MASK | _CACHE_MASK);
396 	pte.pte_low  |= pgprot_val(newprot);
397 	pte.pte_high |= pgprot_val(newprot) & ~(_PFN_MASK | _CACHE_MASK);
398 	return pte;
399 }
400 #else
401 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
402 {
403 	return __pte((pte_val(pte) & _PAGE_CHG_MASK) | pgprot_val(newprot));
404 }
405 #endif
406 
407 
408 extern void __update_tlb(struct vm_area_struct *vma, unsigned long address,
409 	pte_t pte);
410 
411 static inline void update_mmu_cache(struct vm_area_struct *vma,
412 	unsigned long address, pte_t *ptep)
413 {
414 	pte_t pte = *ptep;
415 	__update_tlb(vma, address, pte);
416 }
417 
418 static inline void update_mmu_cache_pmd(struct vm_area_struct *vma,
419 	unsigned long address, pmd_t *pmdp)
420 {
421 	pte_t pte = *(pte_t *)pmdp;
422 
423 	__update_tlb(vma, address, pte);
424 }
425 
426 #define kern_addr_valid(addr)	(1)
427 
428 #ifdef CONFIG_PHYS_ADDR_T_64BIT
429 extern int remap_pfn_range(struct vm_area_struct *vma, unsigned long from, unsigned long pfn, unsigned long size, pgprot_t prot);
430 
431 static inline int io_remap_pfn_range(struct vm_area_struct *vma,
432 		unsigned long vaddr,
433 		unsigned long pfn,
434 		unsigned long size,
435 		pgprot_t prot)
436 {
437 	phys_addr_t phys_addr_high = fixup_bigphys_addr(pfn << PAGE_SHIFT, size);
438 	return remap_pfn_range(vma, vaddr, phys_addr_high >> PAGE_SHIFT, size, prot);
439 }
440 #define io_remap_pfn_range io_remap_pfn_range
441 #endif
442 
443 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
444 
445 extern int has_transparent_hugepage(void);
446 
447 static inline int pmd_trans_huge(pmd_t pmd)
448 {
449 	return !!(pmd_val(pmd) & _PAGE_HUGE);
450 }
451 
452 static inline pmd_t pmd_mkhuge(pmd_t pmd)
453 {
454 	pmd_val(pmd) |= _PAGE_HUGE;
455 
456 	return pmd;
457 }
458 
459 static inline int pmd_trans_splitting(pmd_t pmd)
460 {
461 	return !!(pmd_val(pmd) & _PAGE_SPLITTING);
462 }
463 
464 static inline pmd_t pmd_mksplitting(pmd_t pmd)
465 {
466 	pmd_val(pmd) |= _PAGE_SPLITTING;
467 
468 	return pmd;
469 }
470 
471 extern void set_pmd_at(struct mm_struct *mm, unsigned long addr,
472 		       pmd_t *pmdp, pmd_t pmd);
473 
474 #define __HAVE_ARCH_PMDP_SPLITTING_FLUSH
475 /* Extern to avoid header file madness */
476 extern void pmdp_splitting_flush(struct vm_area_struct *vma,
477 					unsigned long address,
478 					pmd_t *pmdp);
479 
480 #define __HAVE_ARCH_PMD_WRITE
481 static inline int pmd_write(pmd_t pmd)
482 {
483 	return !!(pmd_val(pmd) & _PAGE_WRITE);
484 }
485 
486 static inline pmd_t pmd_wrprotect(pmd_t pmd)
487 {
488 	pmd_val(pmd) &= ~(_PAGE_WRITE | _PAGE_SILENT_WRITE);
489 	return pmd;
490 }
491 
492 static inline pmd_t pmd_mkwrite(pmd_t pmd)
493 {
494 	pmd_val(pmd) |= _PAGE_WRITE;
495 	if (pmd_val(pmd) & _PAGE_MODIFIED)
496 		pmd_val(pmd) |= _PAGE_SILENT_WRITE;
497 
498 	return pmd;
499 }
500 
501 static inline int pmd_dirty(pmd_t pmd)
502 {
503 	return !!(pmd_val(pmd) & _PAGE_MODIFIED);
504 }
505 
506 static inline pmd_t pmd_mkclean(pmd_t pmd)
507 {
508 	pmd_val(pmd) &= ~(_PAGE_MODIFIED | _PAGE_SILENT_WRITE);
509 	return pmd;
510 }
511 
512 static inline pmd_t pmd_mkdirty(pmd_t pmd)
513 {
514 	pmd_val(pmd) |= _PAGE_MODIFIED;
515 	if (pmd_val(pmd) & _PAGE_WRITE)
516 		pmd_val(pmd) |= _PAGE_SILENT_WRITE;
517 
518 	return pmd;
519 }
520 
521 static inline int pmd_young(pmd_t pmd)
522 {
523 	return !!(pmd_val(pmd) & _PAGE_ACCESSED);
524 }
525 
526 static inline pmd_t pmd_mkold(pmd_t pmd)
527 {
528 	pmd_val(pmd) &= ~(_PAGE_ACCESSED|_PAGE_SILENT_READ);
529 
530 	return pmd;
531 }
532 
533 static inline pmd_t pmd_mkyoung(pmd_t pmd)
534 {
535 	pmd_val(pmd) |= _PAGE_ACCESSED;
536 
537 	if (cpu_has_rixi) {
538 		if (!(pmd_val(pmd) & _PAGE_NO_READ))
539 			pmd_val(pmd) |= _PAGE_SILENT_READ;
540 	} else {
541 		if (pmd_val(pmd) & _PAGE_READ)
542 			pmd_val(pmd) |= _PAGE_SILENT_READ;
543 	}
544 
545 	return pmd;
546 }
547 
548 /* Extern to avoid header file madness */
549 extern pmd_t mk_pmd(struct page *page, pgprot_t prot);
550 
551 static inline unsigned long pmd_pfn(pmd_t pmd)
552 {
553 	return pmd_val(pmd) >> _PFN_SHIFT;
554 }
555 
556 static inline struct page *pmd_page(pmd_t pmd)
557 {
558 	if (pmd_trans_huge(pmd))
559 		return pfn_to_page(pmd_pfn(pmd));
560 
561 	return pfn_to_page(pmd_phys(pmd) >> PAGE_SHIFT);
562 }
563 
564 static inline pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot)
565 {
566 	pmd_val(pmd) = (pmd_val(pmd) & _PAGE_CHG_MASK) | pgprot_val(newprot);
567 	return pmd;
568 }
569 
570 static inline pmd_t pmd_mknotpresent(pmd_t pmd)
571 {
572 	pmd_val(pmd) &= ~(_PAGE_PRESENT | _PAGE_VALID | _PAGE_DIRTY);
573 
574 	return pmd;
575 }
576 
577 /*
578  * The generic version pmdp_get_and_clear uses a version of pmd_clear() with a
579  * different prototype.
580  */
581 #define __HAVE_ARCH_PMDP_GET_AND_CLEAR
582 static inline pmd_t pmdp_get_and_clear(struct mm_struct *mm,
583 				       unsigned long address, pmd_t *pmdp)
584 {
585 	pmd_t old = *pmdp;
586 
587 	pmd_clear(pmdp);
588 
589 	return old;
590 }
591 
592 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
593 
594 #include <asm-generic/pgtable.h>
595 
596 /*
597  * uncached accelerated TLB map for video memory access
598  */
599 #ifdef CONFIG_CPU_SUPPORTS_UNCACHED_ACCELERATED
600 #define __HAVE_PHYS_MEM_ACCESS_PROT
601 
602 struct file;
603 pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
604 		unsigned long size, pgprot_t vma_prot);
605 int phys_mem_access_prot_allowed(struct file *file, unsigned long pfn,
606 		unsigned long size, pgprot_t *vma_prot);
607 #endif
608 
609 /*
610  * We provide our own get_unmapped area to cope with the virtual aliasing
611  * constraints placed on us by the cache architecture.
612  */
613 #define HAVE_ARCH_UNMAPPED_AREA
614 #define HAVE_ARCH_UNMAPPED_AREA_TOPDOWN
615 
616 /*
617  * No page table caches to initialise
618  */
619 #define pgtable_cache_init()	do { } while (0)
620 
621 #endif /* _ASM_PGTABLE_H */
622