xref: /linux/arch/mips/include/asm/pgtable.h (revision c7a19c795b4b0a3232c157ed29eea85077e95da6)
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 	if (cpu_has_htw)						\
103 		write_c0_pwctl(read_c0_pwctl() &			\
104 			       ~(1 << MIPS_PWCTL_PWEN_SHIFT));		\
105 } while(0)
106 
107 #define htw_start()							\
108 do {									\
109 	if (cpu_has_htw)						\
110 		write_c0_pwctl(read_c0_pwctl() |			\
111 			       (1 << MIPS_PWCTL_PWEN_SHIFT));		\
112 } while(0)
113 
114 
115 #define htw_reset()							\
116 do {									\
117 	if (cpu_has_htw) {						\
118 		htw_stop();						\
119 		back_to_back_c0_hazard();				\
120 		htw_start();						\
121 		back_to_back_c0_hazard();				\
122 	}								\
123 } while(0)
124 
125 #if defined(CONFIG_64BIT_PHYS_ADDR) && defined(CONFIG_CPU_MIPS32)
126 
127 #define pte_none(pte)		(!(((pte).pte_low | (pte).pte_high) & ~_PAGE_GLOBAL))
128 #define pte_present(pte)	((pte).pte_low & _PAGE_PRESENT)
129 
130 static inline void set_pte(pte_t *ptep, pte_t pte)
131 {
132 	ptep->pte_high = pte.pte_high;
133 	smp_wmb();
134 	ptep->pte_low = pte.pte_low;
135 
136 	if (pte.pte_low & _PAGE_GLOBAL) {
137 		pte_t *buddy = ptep_buddy(ptep);
138 		/*
139 		 * Make sure the buddy is global too (if it's !none,
140 		 * it better already be global)
141 		 */
142 		if (pte_none(*buddy)) {
143 			buddy->pte_low	|= _PAGE_GLOBAL;
144 			buddy->pte_high |= _PAGE_GLOBAL;
145 		}
146 	}
147 }
148 #define set_pte_at(mm, addr, ptep, pteval) set_pte(ptep, pteval)
149 
150 static inline void pte_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
151 {
152 	pte_t null = __pte(0);
153 
154 	/* Preserve global status for the pair */
155 	if (ptep_buddy(ptep)->pte_low & _PAGE_GLOBAL)
156 		null.pte_low = null.pte_high = _PAGE_GLOBAL;
157 
158 	set_pte_at(mm, addr, ptep, null);
159 	htw_reset();
160 }
161 #else
162 
163 #define pte_none(pte)		(!(pte_val(pte) & ~_PAGE_GLOBAL))
164 #define pte_present(pte)	(pte_val(pte) & _PAGE_PRESENT)
165 
166 /*
167  * Certain architectures need to do special things when pte's
168  * within a page table are directly modified.  Thus, the following
169  * hook is made available.
170  */
171 static inline void set_pte(pte_t *ptep, pte_t pteval)
172 {
173 	*ptep = pteval;
174 #if !defined(CONFIG_CPU_R3000) && !defined(CONFIG_CPU_TX39XX)
175 	if (pte_val(pteval) & _PAGE_GLOBAL) {
176 		pte_t *buddy = ptep_buddy(ptep);
177 		/*
178 		 * Make sure the buddy is global too (if it's !none,
179 		 * it better already be global)
180 		 */
181 		if (pte_none(*buddy))
182 			pte_val(*buddy) = pte_val(*buddy) | _PAGE_GLOBAL;
183 	}
184 #endif
185 }
186 #define set_pte_at(mm, addr, ptep, pteval) set_pte(ptep, pteval)
187 
188 static inline void pte_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
189 {
190 #if !defined(CONFIG_CPU_R3000) && !defined(CONFIG_CPU_TX39XX)
191 	/* Preserve global status for the pair */
192 	if (pte_val(*ptep_buddy(ptep)) & _PAGE_GLOBAL)
193 		set_pte_at(mm, addr, ptep, __pte(_PAGE_GLOBAL));
194 	else
195 #endif
196 		set_pte_at(mm, addr, ptep, __pte(0));
197 	htw_reset();
198 }
199 #endif
200 
201 /*
202  * (pmds are folded into puds so this doesn't get actually called,
203  * but the define is needed for a generic inline function.)
204  */
205 #define set_pmd(pmdptr, pmdval) do { *(pmdptr) = (pmdval); } while(0)
206 
207 #ifndef __PAGETABLE_PMD_FOLDED
208 /*
209  * (puds are folded into pgds so this doesn't get actually called,
210  * but the define is needed for a generic inline function.)
211  */
212 #define set_pud(pudptr, pudval) do { *(pudptr) = (pudval); } while(0)
213 #endif
214 
215 #define PGD_T_LOG2	(__builtin_ffs(sizeof(pgd_t)) - 1)
216 #define PMD_T_LOG2	(__builtin_ffs(sizeof(pmd_t)) - 1)
217 #define PTE_T_LOG2	(__builtin_ffs(sizeof(pte_t)) - 1)
218 
219 /*
220  * We used to declare this array with size but gcc 3.3 and older are not able
221  * to find that this expression is a constant, so the size is dropped.
222  */
223 extern pgd_t swapper_pg_dir[];
224 
225 /*
226  * The following only work if pte_present() is true.
227  * Undefined behaviour if not..
228  */
229 #if defined(CONFIG_64BIT_PHYS_ADDR) && defined(CONFIG_CPU_MIPS32)
230 static inline int pte_write(pte_t pte)	{ return pte.pte_low & _PAGE_WRITE; }
231 static inline int pte_dirty(pte_t pte)	{ return pte.pte_low & _PAGE_MODIFIED; }
232 static inline int pte_young(pte_t pte)	{ return pte.pte_low & _PAGE_ACCESSED; }
233 static inline int pte_file(pte_t pte)	{ return pte.pte_low & _PAGE_FILE; }
234 
235 static inline pte_t pte_wrprotect(pte_t pte)
236 {
237 	pte.pte_low  &= ~(_PAGE_WRITE | _PAGE_SILENT_WRITE);
238 	pte.pte_high &= ~_PAGE_SILENT_WRITE;
239 	return pte;
240 }
241 
242 static inline pte_t pte_mkclean(pte_t pte)
243 {
244 	pte.pte_low  &= ~(_PAGE_MODIFIED | _PAGE_SILENT_WRITE);
245 	pte.pte_high &= ~_PAGE_SILENT_WRITE;
246 	return pte;
247 }
248 
249 static inline pte_t pte_mkold(pte_t pte)
250 {
251 	pte.pte_low  &= ~(_PAGE_ACCESSED | _PAGE_SILENT_READ);
252 	pte.pte_high &= ~_PAGE_SILENT_READ;
253 	return pte;
254 }
255 
256 static inline pte_t pte_mkwrite(pte_t pte)
257 {
258 	pte.pte_low |= _PAGE_WRITE;
259 	if (pte.pte_low & _PAGE_MODIFIED) {
260 		pte.pte_low  |= _PAGE_SILENT_WRITE;
261 		pte.pte_high |= _PAGE_SILENT_WRITE;
262 	}
263 	return pte;
264 }
265 
266 static inline pte_t pte_mkdirty(pte_t pte)
267 {
268 	pte.pte_low |= _PAGE_MODIFIED;
269 	if (pte.pte_low & _PAGE_WRITE) {
270 		pte.pte_low  |= _PAGE_SILENT_WRITE;
271 		pte.pte_high |= _PAGE_SILENT_WRITE;
272 	}
273 	return pte;
274 }
275 
276 static inline pte_t pte_mkyoung(pte_t pte)
277 {
278 	pte.pte_low |= _PAGE_ACCESSED;
279 	if (pte.pte_low & _PAGE_READ) {
280 		pte.pte_low  |= _PAGE_SILENT_READ;
281 		pte.pte_high |= _PAGE_SILENT_READ;
282 	}
283 	return pte;
284 }
285 #else
286 static inline int pte_write(pte_t pte)	{ return pte_val(pte) & _PAGE_WRITE; }
287 static inline int pte_dirty(pte_t pte)	{ return pte_val(pte) & _PAGE_MODIFIED; }
288 static inline int pte_young(pte_t pte)	{ return pte_val(pte) & _PAGE_ACCESSED; }
289 static inline int pte_file(pte_t pte)	{ return pte_val(pte) & _PAGE_FILE; }
290 
291 static inline pte_t pte_wrprotect(pte_t pte)
292 {
293 	pte_val(pte) &= ~(_PAGE_WRITE | _PAGE_SILENT_WRITE);
294 	return pte;
295 }
296 
297 static inline pte_t pte_mkclean(pte_t pte)
298 {
299 	pte_val(pte) &= ~(_PAGE_MODIFIED|_PAGE_SILENT_WRITE);
300 	return pte;
301 }
302 
303 static inline pte_t pte_mkold(pte_t pte)
304 {
305 	pte_val(pte) &= ~(_PAGE_ACCESSED|_PAGE_SILENT_READ);
306 	return pte;
307 }
308 
309 static inline pte_t pte_mkwrite(pte_t pte)
310 {
311 	pte_val(pte) |= _PAGE_WRITE;
312 	if (pte_val(pte) & _PAGE_MODIFIED)
313 		pte_val(pte) |= _PAGE_SILENT_WRITE;
314 	return pte;
315 }
316 
317 static inline pte_t pte_mkdirty(pte_t pte)
318 {
319 	pte_val(pte) |= _PAGE_MODIFIED;
320 	if (pte_val(pte) & _PAGE_WRITE)
321 		pte_val(pte) |= _PAGE_SILENT_WRITE;
322 	return pte;
323 }
324 
325 static inline pte_t pte_mkyoung(pte_t pte)
326 {
327 	pte_val(pte) |= _PAGE_ACCESSED;
328 	if (cpu_has_rixi) {
329 		if (!(pte_val(pte) & _PAGE_NO_READ))
330 			pte_val(pte) |= _PAGE_SILENT_READ;
331 	} else {
332 		if (pte_val(pte) & _PAGE_READ)
333 			pte_val(pte) |= _PAGE_SILENT_READ;
334 	}
335 	return pte;
336 }
337 
338 #ifdef _PAGE_HUGE
339 static inline int pte_huge(pte_t pte)	{ return pte_val(pte) & _PAGE_HUGE; }
340 
341 static inline pte_t pte_mkhuge(pte_t pte)
342 {
343 	pte_val(pte) |= _PAGE_HUGE;
344 	return pte;
345 }
346 #endif /* _PAGE_HUGE */
347 #endif
348 static inline int pte_special(pte_t pte)	{ return 0; }
349 static inline pte_t pte_mkspecial(pte_t pte)	{ return pte; }
350 
351 /*
352  * Macro to make mark a page protection value as "uncacheable".	 Note
353  * that "protection" is really a misnomer here as the protection value
354  * contains the memory attribute bits, dirty bits, and various other
355  * bits as well.
356  */
357 #define pgprot_noncached pgprot_noncached
358 
359 static inline pgprot_t pgprot_noncached(pgprot_t _prot)
360 {
361 	unsigned long prot = pgprot_val(_prot);
362 
363 	prot = (prot & ~_CACHE_MASK) | _CACHE_UNCACHED;
364 
365 	return __pgprot(prot);
366 }
367 
368 /*
369  * Conversion functions: convert a page and protection to a page entry,
370  * and a page entry and page directory to the page they refer to.
371  */
372 #define mk_pte(page, pgprot)	pfn_pte(page_to_pfn(page), (pgprot))
373 
374 #if defined(CONFIG_64BIT_PHYS_ADDR) && defined(CONFIG_CPU_MIPS32)
375 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
376 {
377 	pte.pte_low  &= _PAGE_CHG_MASK;
378 	pte.pte_high &= ~0x3f;
379 	pte.pte_low  |= pgprot_val(newprot);
380 	pte.pte_high |= pgprot_val(newprot) & 0x3f;
381 	return pte;
382 }
383 #else
384 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
385 {
386 	return __pte((pte_val(pte) & _PAGE_CHG_MASK) | pgprot_val(newprot));
387 }
388 #endif
389 
390 
391 extern void __update_tlb(struct vm_area_struct *vma, unsigned long address,
392 	pte_t pte);
393 extern void __update_cache(struct vm_area_struct *vma, unsigned long address,
394 	pte_t pte);
395 
396 static inline void update_mmu_cache(struct vm_area_struct *vma,
397 	unsigned long address, pte_t *ptep)
398 {
399 	pte_t pte = *ptep;
400 	__update_tlb(vma, address, pte);
401 	__update_cache(vma, address, pte);
402 }
403 
404 static inline void update_mmu_cache_pmd(struct vm_area_struct *vma,
405 	unsigned long address, pmd_t *pmdp)
406 {
407 	pte_t pte = *(pte_t *)pmdp;
408 
409 	__update_tlb(vma, address, pte);
410 }
411 
412 #define kern_addr_valid(addr)	(1)
413 
414 #ifdef CONFIG_64BIT_PHYS_ADDR
415 extern int remap_pfn_range(struct vm_area_struct *vma, unsigned long from, unsigned long pfn, unsigned long size, pgprot_t prot);
416 
417 static inline int io_remap_pfn_range(struct vm_area_struct *vma,
418 		unsigned long vaddr,
419 		unsigned long pfn,
420 		unsigned long size,
421 		pgprot_t prot)
422 {
423 	phys_t phys_addr_high = fixup_bigphys_addr(pfn << PAGE_SHIFT, size);
424 	return remap_pfn_range(vma, vaddr, phys_addr_high >> PAGE_SHIFT, size, prot);
425 }
426 #define io_remap_pfn_range io_remap_pfn_range
427 #endif
428 
429 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
430 
431 extern int has_transparent_hugepage(void);
432 
433 static inline int pmd_trans_huge(pmd_t pmd)
434 {
435 	return !!(pmd_val(pmd) & _PAGE_HUGE);
436 }
437 
438 static inline pmd_t pmd_mkhuge(pmd_t pmd)
439 {
440 	pmd_val(pmd) |= _PAGE_HUGE;
441 
442 	return pmd;
443 }
444 
445 static inline int pmd_trans_splitting(pmd_t pmd)
446 {
447 	return !!(pmd_val(pmd) & _PAGE_SPLITTING);
448 }
449 
450 static inline pmd_t pmd_mksplitting(pmd_t pmd)
451 {
452 	pmd_val(pmd) |= _PAGE_SPLITTING;
453 
454 	return pmd;
455 }
456 
457 extern void set_pmd_at(struct mm_struct *mm, unsigned long addr,
458 		       pmd_t *pmdp, pmd_t pmd);
459 
460 #define __HAVE_ARCH_PMDP_SPLITTING_FLUSH
461 /* Extern to avoid header file madness */
462 extern void pmdp_splitting_flush(struct vm_area_struct *vma,
463 					unsigned long address,
464 					pmd_t *pmdp);
465 
466 #define __HAVE_ARCH_PMD_WRITE
467 static inline int pmd_write(pmd_t pmd)
468 {
469 	return !!(pmd_val(pmd) & _PAGE_WRITE);
470 }
471 
472 static inline pmd_t pmd_wrprotect(pmd_t pmd)
473 {
474 	pmd_val(pmd) &= ~(_PAGE_WRITE | _PAGE_SILENT_WRITE);
475 	return pmd;
476 }
477 
478 static inline pmd_t pmd_mkwrite(pmd_t pmd)
479 {
480 	pmd_val(pmd) |= _PAGE_WRITE;
481 	if (pmd_val(pmd) & _PAGE_MODIFIED)
482 		pmd_val(pmd) |= _PAGE_SILENT_WRITE;
483 
484 	return pmd;
485 }
486 
487 static inline int pmd_dirty(pmd_t pmd)
488 {
489 	return !!(pmd_val(pmd) & _PAGE_MODIFIED);
490 }
491 
492 static inline pmd_t pmd_mkclean(pmd_t pmd)
493 {
494 	pmd_val(pmd) &= ~(_PAGE_MODIFIED | _PAGE_SILENT_WRITE);
495 	return pmd;
496 }
497 
498 static inline pmd_t pmd_mkdirty(pmd_t pmd)
499 {
500 	pmd_val(pmd) |= _PAGE_MODIFIED;
501 	if (pmd_val(pmd) & _PAGE_WRITE)
502 		pmd_val(pmd) |= _PAGE_SILENT_WRITE;
503 
504 	return pmd;
505 }
506 
507 static inline int pmd_young(pmd_t pmd)
508 {
509 	return !!(pmd_val(pmd) & _PAGE_ACCESSED);
510 }
511 
512 static inline pmd_t pmd_mkold(pmd_t pmd)
513 {
514 	pmd_val(pmd) &= ~(_PAGE_ACCESSED|_PAGE_SILENT_READ);
515 
516 	return pmd;
517 }
518 
519 static inline pmd_t pmd_mkyoung(pmd_t pmd)
520 {
521 	pmd_val(pmd) |= _PAGE_ACCESSED;
522 
523 	if (cpu_has_rixi) {
524 		if (!(pmd_val(pmd) & _PAGE_NO_READ))
525 			pmd_val(pmd) |= _PAGE_SILENT_READ;
526 	} else {
527 		if (pmd_val(pmd) & _PAGE_READ)
528 			pmd_val(pmd) |= _PAGE_SILENT_READ;
529 	}
530 
531 	return pmd;
532 }
533 
534 /* Extern to avoid header file madness */
535 extern pmd_t mk_pmd(struct page *page, pgprot_t prot);
536 
537 static inline unsigned long pmd_pfn(pmd_t pmd)
538 {
539 	return pmd_val(pmd) >> _PFN_SHIFT;
540 }
541 
542 static inline struct page *pmd_page(pmd_t pmd)
543 {
544 	if (pmd_trans_huge(pmd))
545 		return pfn_to_page(pmd_pfn(pmd));
546 
547 	return pfn_to_page(pmd_phys(pmd) >> PAGE_SHIFT);
548 }
549 
550 static inline pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot)
551 {
552 	pmd_val(pmd) = (pmd_val(pmd) & _PAGE_CHG_MASK) | pgprot_val(newprot);
553 	return pmd;
554 }
555 
556 static inline pmd_t pmd_mknotpresent(pmd_t pmd)
557 {
558 	pmd_val(pmd) &= ~(_PAGE_PRESENT | _PAGE_VALID | _PAGE_DIRTY);
559 
560 	return pmd;
561 }
562 
563 /*
564  * The generic version pmdp_get_and_clear uses a version of pmd_clear() with a
565  * different prototype.
566  */
567 #define __HAVE_ARCH_PMDP_GET_AND_CLEAR
568 static inline pmd_t pmdp_get_and_clear(struct mm_struct *mm,
569 				       unsigned long address, pmd_t *pmdp)
570 {
571 	pmd_t old = *pmdp;
572 
573 	pmd_clear(pmdp);
574 
575 	return old;
576 }
577 
578 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
579 
580 #include <asm-generic/pgtable.h>
581 
582 /*
583  * uncached accelerated TLB map for video memory access
584  */
585 #ifdef CONFIG_CPU_SUPPORTS_UNCACHED_ACCELERATED
586 #define __HAVE_PHYS_MEM_ACCESS_PROT
587 
588 struct file;
589 pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
590 		unsigned long size, pgprot_t vma_prot);
591 int phys_mem_access_prot_allowed(struct file *file, unsigned long pfn,
592 		unsigned long size, pgprot_t *vma_prot);
593 #endif
594 
595 /*
596  * We provide our own get_unmapped area to cope with the virtual aliasing
597  * constraints placed on us by the cache architecture.
598  */
599 #define HAVE_ARCH_UNMAPPED_AREA
600 #define HAVE_ARCH_UNMAPPED_AREA_TOPDOWN
601 
602 /*
603  * No page table caches to initialise
604  */
605 #define pgtable_cache_init()	do { } while (0)
606 
607 #endif /* _ASM_PGTABLE_H */
608