summaryrefslogtreecommitdiff
path: root/arch/mips/include/asm/pgtable.h
blob: 583ff42154794da86c5cc9b64ae9e81e4507e057 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
/*
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * Copyright (C) 2003 Ralf Baechle
 */
#ifndef _ASM_PGTABLE_H
#define _ASM_PGTABLE_H

#include <linux/mm_types.h>
#include <linux/mmzone.h>
#ifdef CONFIG_32BIT
#include <asm/pgtable-32.h>
#endif
#ifdef CONFIG_64BIT
#include <asm/pgtable-64.h>
#endif

#include <asm/io.h>
#include <asm/pgtable-bits.h>

struct mm_struct;
struct vm_area_struct;

#define PAGE_NONE	__pgprot(_PAGE_PRESENT | _CACHE_CACHABLE_NONCOHERENT)
#define PAGE_SHARED	__pgprot(_PAGE_PRESENT | _PAGE_WRITE | (cpu_has_rixi ? 0 : _PAGE_READ) | \
				 _page_cachable_default)
#define PAGE_COPY	__pgprot(_PAGE_PRESENT | (cpu_has_rixi ? 0 : _PAGE_READ) | \
				 (cpu_has_rixi ?  _PAGE_NO_EXEC : 0) | _page_cachable_default)
#define PAGE_READONLY	__pgprot(_PAGE_PRESENT | (cpu_has_rixi ? 0 : _PAGE_READ) | \
				 _page_cachable_default)
#define PAGE_KERNEL	__pgprot(_PAGE_PRESENT | __READABLE | __WRITEABLE | \
				 _PAGE_GLOBAL | _page_cachable_default)
#define PAGE_KERNEL_NC	__pgprot(_PAGE_PRESENT | __READABLE | __WRITEABLE | \
				 _PAGE_GLOBAL | _CACHE_CACHABLE_NONCOHERENT)
#define PAGE_USERIO	__pgprot(_PAGE_PRESENT | (cpu_has_rixi ? 0 : _PAGE_READ) | _PAGE_WRITE | \
				 _page_cachable_default)
#define PAGE_KERNEL_UNCACHED __pgprot(_PAGE_PRESENT | __READABLE | \
			__WRITEABLE | _PAGE_GLOBAL | _CACHE_UNCACHED)

/*
 * If _PAGE_NO_EXEC is not defined, we can't do page protection for
 * execute, and consider it to be the same as read. Also, write
 * permissions imply read permissions. This is the closest we can get
 * by reasonable means..
 */

/*
 * Dummy values to fill the table in mmap.c
 * The real values will be generated at runtime
 */
#define __P000 __pgprot(0)
#define __P001 __pgprot(0)
#define __P010 __pgprot(0)
#define __P011 __pgprot(0)
#define __P100 __pgprot(0)
#define __P101 __pgprot(0)
#define __P110 __pgprot(0)
#define __P111 __pgprot(0)

#define __S000 __pgprot(0)
#define __S001 __pgprot(0)
#define __S010 __pgprot(0)
#define __S011 __pgprot(0)
#define __S100 __pgprot(0)
#define __S101 __pgprot(0)
#define __S110 __pgprot(0)
#define __S111 __pgprot(0)

extern unsigned long _page_cachable_default;

/*
 * ZERO_PAGE is a global shared page that is always zero; used
 * for zero-mapped memory areas etc..
 */

extern unsigned long empty_zero_page;
extern unsigned long zero_page_mask;

#define ZERO_PAGE(vaddr) \
	(virt_to_page((void *)(empty_zero_page + (((unsigned long)(vaddr)) & zero_page_mask))))
#define __HAVE_COLOR_ZERO_PAGE

extern void paging_init(void);

/*
 * Conversion functions: convert a page and protection to a page entry,
 * and a page entry and page directory to the page they refer to.
 */
#define pmd_phys(pmd)		virt_to_phys((void *)pmd_val(pmd))

#define __pmd_page(pmd)		(pfn_to_page(pmd_phys(pmd) >> PAGE_SHIFT))
#ifndef CONFIG_TRANSPARENT_HUGEPAGE
#define pmd_page(pmd)		__pmd_page(pmd)
#endif /* CONFIG_TRANSPARENT_HUGEPAGE  */

#define pmd_page_vaddr(pmd)	pmd_val(pmd)

#define htw_stop()							\
do {									\
	if (cpu_has_htw)						\
		write_c0_pwctl(read_c0_pwctl() &			\
			       ~(1 << MIPS_PWCTL_PWEN_SHIFT));		\
} while(0)

#define htw_start()							\
do {									\
	if (cpu_has_htw)						\
		write_c0_pwctl(read_c0_pwctl() |			\
			       (1 << MIPS_PWCTL_PWEN_SHIFT));		\
} while(0)


#define htw_reset()							\
do {									\
	if (cpu_has_htw) {						\
		htw_stop();						\
		back_to_back_c0_hazard();				\
		htw_start();						\
		back_to_back_c0_hazard();				\
	}								\
} while(0)

extern void set_pte_at(struct mm_struct *mm, unsigned long addr, pte_t *ptep,
	pte_t pteval);

#if defined(CONFIG_PHYS_ADDR_T_64BIT) && defined(CONFIG_CPU_MIPS32)

#define pte_none(pte)		(!(((pte).pte_low | (pte).pte_high) & ~_PAGE_GLOBAL))
#define pte_present(pte)	((pte).pte_low & _PAGE_PRESENT)

static inline void set_pte(pte_t *ptep, pte_t pte)
{
	ptep->pte_high = pte.pte_high;
	smp_wmb();
	ptep->pte_low = pte.pte_low;

	if (pte.pte_low & _PAGE_GLOBAL) {
		pte_t *buddy = ptep_buddy(ptep);
		/*
		 * Make sure the buddy is global too (if it's !none,
		 * it better already be global)
		 */
		if (pte_none(*buddy)) {
			buddy->pte_low	|= _PAGE_GLOBAL;
			buddy->pte_high |= _PAGE_GLOBAL;
		}
	}
}

static inline void pte_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
{
	pte_t null = __pte(0);

	/* Preserve global status for the pair */
	if (ptep_buddy(ptep)->pte_low & _PAGE_GLOBAL)
		null.pte_low = null.pte_high = _PAGE_GLOBAL;

	set_pte_at(mm, addr, ptep, null);
	htw_reset();
}
#else

#define pte_none(pte)		(!(pte_val(pte) & ~_PAGE_GLOBAL))
#define pte_present(pte)	(pte_val(pte) & _PAGE_PRESENT)

/*
 * Certain architectures need to do special things when pte's
 * within a page table are directly modified.  Thus, the following
 * hook is made available.
 */
static inline void set_pte(pte_t *ptep, pte_t pteval)
{
	*ptep = pteval;
#if !defined(CONFIG_CPU_R3000) && !defined(CONFIG_CPU_TX39XX)
	if (pte_val(pteval) & _PAGE_GLOBAL) {
		pte_t *buddy = ptep_buddy(ptep);
		/*
		 * Make sure the buddy is global too (if it's !none,
		 * it better already be global)
		 */
		if (pte_none(*buddy))
			pte_val(*buddy) = pte_val(*buddy) | _PAGE_GLOBAL;
	}
#endif
}

static inline void pte_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
{
#if !defined(CONFIG_CPU_R3000) && !defined(CONFIG_CPU_TX39XX)
	/* Preserve global status for the pair */
	if (pte_val(*ptep_buddy(ptep)) & _PAGE_GLOBAL)
		set_pte_at(mm, addr, ptep, __pte(_PAGE_GLOBAL));
	else
#endif
		set_pte_at(mm, addr, ptep, __pte(0));
	htw_reset();
}
#endif

/*
 * (pmds are folded into puds so this doesn't get actually called,
 * but the define is needed for a generic inline function.)
 */
#define set_pmd(pmdptr, pmdval) do { *(pmdptr) = (pmdval); } while(0)

#ifndef __PAGETABLE_PMD_FOLDED
/*
 * (puds are folded into pgds so this doesn't get actually called,
 * but the define is needed for a generic inline function.)
 */
#define set_pud(pudptr, pudval) do { *(pudptr) = (pudval); } while(0)
#endif

#define PGD_T_LOG2	(__builtin_ffs(sizeof(pgd_t)) - 1)
#define PMD_T_LOG2	(__builtin_ffs(sizeof(pmd_t)) - 1)
#define PTE_T_LOG2	(__builtin_ffs(sizeof(pte_t)) - 1)

/*
 * We used to declare this array with size but gcc 3.3 and older are not able
 * to find that this expression is a constant, so the size is dropped.
 */
extern pgd_t swapper_pg_dir[];

/*
 * The following only work if pte_present() is true.
 * Undefined behaviour if not..
 */
#if defined(CONFIG_PHYS_ADDR_T_64BIT) && defined(CONFIG_CPU_MIPS32)
static inline int pte_write(pte_t pte)	{ return pte.pte_low & _PAGE_WRITE; }
static inline int pte_dirty(pte_t pte)	{ return pte.pte_low & _PAGE_MODIFIED; }
static inline int pte_young(pte_t pte)	{ return pte.pte_low & _PAGE_ACCESSED; }

static inline pte_t pte_wrprotect(pte_t pte)
{
	pte.pte_low  &= ~(_PAGE_WRITE | _PAGE_SILENT_WRITE);
	pte.pte_high &= ~_PAGE_SILENT_WRITE;
	return pte;
}

static inline pte_t pte_mkclean(pte_t pte)
{
	pte.pte_low  &= ~(_PAGE_MODIFIED | _PAGE_SILENT_WRITE);
	pte.pte_high &= ~_PAGE_SILENT_WRITE;
	return pte;
}

static inline pte_t pte_mkold(pte_t pte)
{
	pte.pte_low  &= ~(_PAGE_ACCESSED | _PAGE_SILENT_READ);
	pte.pte_high &= ~_PAGE_SILENT_READ;
	return pte;
}

static inline pte_t pte_mkwrite(pte_t pte)
{
	pte.pte_low |= _PAGE_WRITE;
	if (pte.pte_low & _PAGE_MODIFIED) {
		pte.pte_low  |= _PAGE_SILENT_WRITE;
		pte.pte_high |= _PAGE_SILENT_WRITE;
	}
	return pte;
}

static inline pte_t pte_mkdirty(pte_t pte)
{
	pte.pte_low |= _PAGE_MODIFIED;
	if (pte.pte_low & _PAGE_WRITE) {
		pte.pte_low  |= _PAGE_SILENT_WRITE;
		pte.pte_high |= _PAGE_SILENT_WRITE;
	}
	return pte;
}

static inline pte_t pte_mkyoung(pte_t pte)
{
	pte.pte_low |= _PAGE_ACCESSED;
	if (pte.pte_low & _PAGE_READ) {
		pte.pte_low  |= _PAGE_SILENT_READ;
		pte.pte_high |= _PAGE_SILENT_READ;
	}
	return pte;
}
#else
static inline int pte_write(pte_t pte)	{ return pte_val(pte) & _PAGE_WRITE; }
static inline int pte_dirty(pte_t pte)	{ return pte_val(pte) & _PAGE_MODIFIED; }
static inline int pte_young(pte_t pte)	{ return pte_val(pte) & _PAGE_ACCESSED; }

static inline pte_t pte_wrprotect(pte_t pte)
{
	pte_val(pte) &= ~(_PAGE_WRITE | _PAGE_SILENT_WRITE);
	return pte;
}

static inline pte_t pte_mkclean(pte_t pte)
{
	pte_val(pte) &= ~(_PAGE_MODIFIED | _PAGE_SILENT_WRITE);
	return pte;
}

static inline pte_t pte_mkold(pte_t pte)
{
	pte_val(pte) &= ~(_PAGE_ACCESSED | _PAGE_SILENT_READ);
	return pte;
}

static inline pte_t pte_mkwrite(pte_t pte)
{
	pte_val(pte) |= _PAGE_WRITE;
	if (pte_val(pte) & _PAGE_MODIFIED)
		pte_val(pte) |= _PAGE_SILENT_WRITE;
	return pte;
}

static inline pte_t pte_mkdirty(pte_t pte)
{
	pte_val(pte) |= _PAGE_MODIFIED;
	if (pte_val(pte) & _PAGE_WRITE)
		pte_val(pte) |= _PAGE_SILENT_WRITE;
	return pte;
}

static inline pte_t pte_mkyoung(pte_t pte)
{
	pte_val(pte) |= _PAGE_ACCESSED;
	if (cpu_has_rixi) {
		if (!(pte_val(pte) & _PAGE_NO_READ))
			pte_val(pte) |= _PAGE_SILENT_READ;
	} else {
		if (pte_val(pte) & _PAGE_READ)
			pte_val(pte) |= _PAGE_SILENT_READ;
	}
	return pte;
}

#ifdef _PAGE_HUGE
static inline int pte_huge(pte_t pte)	{ return pte_val(pte) & _PAGE_HUGE; }

static inline pte_t pte_mkhuge(pte_t pte)
{
	pte_val(pte) |= _PAGE_HUGE;
	return pte;
}
#endif /* _PAGE_HUGE */
#endif
static inline int pte_special(pte_t pte)	{ return 0; }
static inline pte_t pte_mkspecial(pte_t pte)	{ return pte; }

/*
 * Macro to make mark a page protection value as "uncacheable".	 Note
 * that "protection" is really a misnomer here as the protection value
 * contains the memory attribute bits, dirty bits, and various other
 * bits as well.
 */
#define pgprot_noncached pgprot_noncached

static inline pgprot_t pgprot_noncached(pgprot_t _prot)
{
	unsigned long prot = pgprot_val(_prot);

	prot = (prot & ~_CACHE_MASK) | _CACHE_UNCACHED;

	return __pgprot(prot);
}

static inline pgprot_t pgprot_writecombine(pgprot_t _prot)
{
	unsigned long prot = pgprot_val(_prot);

	/* cpu_data[0].writecombine is already shifted by _CACHE_SHIFT */
	prot = (prot & ~_CACHE_MASK) | cpu_data[0].writecombine;

	return __pgprot(prot);
}

/*
 * Conversion functions: convert a page and protection to a page entry,
 * and a page entry and page directory to the page they refer to.
 */
#define mk_pte(page, pgprot)	pfn_pte(page_to_pfn(page), (pgprot))

#if defined(CONFIG_PHYS_ADDR_T_64BIT) && defined(CONFIG_CPU_MIPS32)
static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
{
	pte.pte_low  &= _PAGE_CHG_MASK;
	pte.pte_high &= (_PFN_MASK | _CACHE_MASK);
	pte.pte_low  |= pgprot_val(newprot);
	pte.pte_high |= pgprot_val(newprot) & ~(_PFN_MASK | _CACHE_MASK);
	return pte;
}
#else
static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
{
	return __pte((pte_val(pte) & _PAGE_CHG_MASK) | pgprot_val(newprot));
}
#endif


extern void __update_tlb(struct vm_area_struct *vma, unsigned long address,
	pte_t pte);

static inline void update_mmu_cache(struct vm_area_struct *vma,
	unsigned long address, pte_t *ptep)
{
	pte_t pte = *ptep;
	__update_tlb(vma, address, pte);
}

static inline void update_mmu_cache_pmd(struct vm_area_struct *vma,
	unsigned long address, pmd_t *pmdp)
{
	pte_t pte = *(pte_t *)pmdp;

	__update_tlb(vma, address, pte);
}

#define kern_addr_valid(addr)	(1)

#ifdef CONFIG_PHYS_ADDR_T_64BIT
extern int remap_pfn_range(struct vm_area_struct *vma, unsigned long from, unsigned long pfn, unsigned long size, pgprot_t prot);

static inline int io_remap_pfn_range(struct vm_area_struct *vma,
		unsigned long vaddr,
		unsigned long pfn,
		unsigned long size,
		pgprot_t prot)
{
	phys_addr_t phys_addr_high = fixup_bigphys_addr(pfn << PAGE_SHIFT, size);
	return remap_pfn_range(vma, vaddr, phys_addr_high >> PAGE_SHIFT, size, prot);
}
#define io_remap_pfn_range io_remap_pfn_range
#endif

#ifdef CONFIG_TRANSPARENT_HUGEPAGE

extern int has_transparent_hugepage(void);

static inline int pmd_trans_huge(pmd_t pmd)
{
	return !!(pmd_val(pmd) & _PAGE_HUGE);
}

static inline pmd_t pmd_mkhuge(pmd_t pmd)
{
	pmd_val(pmd) |= _PAGE_HUGE;

	return pmd;
}

static inline int pmd_trans_splitting(pmd_t pmd)
{
	return !!(pmd_val(pmd) & _PAGE_SPLITTING);
}

static inline pmd_t pmd_mksplitting(pmd_t pmd)
{
	pmd_val(pmd) |= _PAGE_SPLITTING;

	return pmd;
}

extern void set_pmd_at(struct mm_struct *mm, unsigned long addr,
		       pmd_t *pmdp, pmd_t pmd);

#define __HAVE_ARCH_PMDP_SPLITTING_FLUSH
/* Extern to avoid header file madness */
extern void pmdp_splitting_flush(struct vm_area_struct *vma,
					unsigned long address,
					pmd_t *pmdp);

#define __HAVE_ARCH_PMD_WRITE
static inline int pmd_write(pmd_t pmd)
{
	return !!(pmd_val(pmd) & _PAGE_WRITE);
}

static inline pmd_t pmd_wrprotect(pmd_t pmd)
{
	pmd_val(pmd) &= ~(_PAGE_WRITE | _PAGE_SILENT_WRITE);
	return pmd;
}

static inline pmd_t pmd_mkwrite(pmd_t pmd)
{
	pmd_val(pmd) |= _PAGE_WRITE;
	if (pmd_val(pmd) & _PAGE_MODIFIED)
		pmd_val(pmd) |= _PAGE_SILENT_WRITE;

	return pmd;
}

static inline int pmd_dirty(pmd_t pmd)
{
	return !!(pmd_val(pmd) & _PAGE_MODIFIED);
}

static inline pmd_t pmd_mkclean(pmd_t pmd)
{
	pmd_val(pmd) &= ~(_PAGE_MODIFIED | _PAGE_SILENT_WRITE);
	return pmd;
}

static inline pmd_t pmd_mkdirty(pmd_t pmd)
{
	pmd_val(pmd) |= _PAGE_MODIFIED;
	if (pmd_val(pmd) & _PAGE_WRITE)
		pmd_val(pmd) |= _PAGE_SILENT_WRITE;

	return pmd;
}

static inline int pmd_young(pmd_t pmd)
{
	return !!(pmd_val(pmd) & _PAGE_ACCESSED);
}

static inline pmd_t pmd_mkold(pmd_t pmd)
{
	pmd_val(pmd) &= ~(_PAGE_ACCESSED|_PAGE_SILENT_READ);

	return pmd;
}

static inline pmd_t pmd_mkyoung(pmd_t pmd)
{
	pmd_val(pmd) |= _PAGE_ACCESSED;

	if (cpu_has_rixi) {
		if (!(pmd_val(pmd) & _PAGE_NO_READ))
			pmd_val(pmd) |= _PAGE_SILENT_READ;
	} else {
		if (pmd_val(pmd) & _PAGE_READ)
			pmd_val(pmd) |= _PAGE_SILENT_READ;
	}

	return pmd;
}

/* Extern to avoid header file madness */
extern pmd_t mk_pmd(struct page *page, pgprot_t prot);

static inline unsigned long pmd_pfn(pmd_t pmd)
{
	return pmd_val(pmd) >> _PFN_SHIFT;
}

static inline struct page *pmd_page(pmd_t pmd)
{
	if (pmd_trans_huge(pmd))
		return pfn_to_page(pmd_pfn(pmd));

	return pfn_to_page(pmd_phys(pmd) >> PAGE_SHIFT);
}

static inline pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot)
{
	pmd_val(pmd) = (pmd_val(pmd) & _PAGE_CHG_MASK) | pgprot_val(newprot);
	return pmd;
}

static inline pmd_t pmd_mknotpresent(pmd_t pmd)
{
	pmd_val(pmd) &= ~(_PAGE_PRESENT | _PAGE_VALID | _PAGE_DIRTY);

	return pmd;
}

/*
 * The generic version pmdp_get_and_clear uses a version of pmd_clear() with a
 * different prototype.
 */
#define __HAVE_ARCH_PMDP_GET_AND_CLEAR
static inline pmd_t pmdp_get_and_clear(struct mm_struct *mm,
				       unsigned long address, pmd_t *pmdp)
{
	pmd_t old = *pmdp;

	pmd_clear(pmdp);

	return old;
}

#endif /* CONFIG_TRANSPARENT_HUGEPAGE */

#include <asm-generic/pgtable.h>

/*
 * uncached accelerated TLB map for video memory access
 */
#ifdef CONFIG_CPU_SUPPORTS_UNCACHED_ACCELERATED
#define __HAVE_PHYS_MEM_ACCESS_PROT

struct file;
pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
		unsigned long size, pgprot_t vma_prot);
int phys_mem_access_prot_allowed(struct file *file, unsigned long pfn,
		unsigned long size, pgprot_t *vma_prot);
#endif

/*
 * We provide our own get_unmapped area to cope with the virtual aliasing
 * constraints placed on us by the cache architecture.
 */
#define HAVE_ARCH_UNMAPPED_AREA
#define HAVE_ARCH_UNMAPPED_AREA_TOPDOWN

/*
 * No page table caches to initialise
 */
#define pgtable_cache_init()	do { } while (0)

#endif /* _ASM_PGTABLE_H */