aboutsummaryrefslogtreecommitdiffstats
path: root/include/asm-sh/pgtable.h
blob: e3fae12c0e499574f62e0300391ebd7a5328dbf0 (plain)
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
/*
 * This file contains the functions and defines necessary to modify and
 * use the SuperH page table tree.
 *
 * Copyright (C) 1999 Niibe Yutaka
 * Copyright (C) 2002 - 2005 Paul Mundt
 *
 * 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.
 */
#ifndef __ASM_SH_PGTABLE_H
#define __ASM_SH_PGTABLE_H

#include <asm-generic/pgtable-nopmd.h>
#include <asm/page.h>

#ifndef __ASSEMBLY__
#include <asm/addrspace.h>
#include <asm/fixmap.h>

/*
 * ZERO_PAGE is a global shared page that is always zero: used
 * for zero-mapped memory areas etc..
 */
extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)];
#define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page))

#endif /* !__ASSEMBLY__ */

/*
 * traditional two-level paging structure
 */
/* PTE bits */
#ifdef CONFIG_X2TLB
# define PTE_MAGNITUDE	3	/* 64-bit PTEs on extended mode SH-X2 TLB */
#else
# define PTE_MAGNITUDE	2	/* 32-bit PTEs */
#endif
#define PTE_SHIFT	PAGE_SHIFT
#define PTE_BITS	(PTE_SHIFT - PTE_MAGNITUDE)

/* PGD bits */
#define PGDIR_SHIFT	(PTE_SHIFT + PTE_BITS)
#define PGDIR_BITS	(32 - PGDIR_SHIFT)
#define PGDIR_SIZE	(1UL << PGDIR_SHIFT)
#define PGDIR_MASK	(~(PGDIR_SIZE-1))

/* Entries per level */
#define PTRS_PER_PTE	(PAGE_SIZE / (1 << PTE_MAGNITUDE))
#define PTRS_PER_PGD	(PAGE_SIZE / 4)

#define USER_PTRS_PER_PGD	(TASK_SIZE/PGDIR_SIZE)
#define FIRST_USER_ADDRESS	0

#define PTE_PHYS_MASK		(0x20000000 - PAGE_SIZE)

#define VMALLOC_START	(P3SEG)
#define VMALLOC_END	(FIXADDR_START-2*PAGE_SIZE)

/*
 * Linux PTEL encoding.
 *
 * Hardware and software bit definitions for the PTEL value (see below for
 * notes on SH-X2 MMUs and 64-bit PTEs):
 *
 * - Bits 0 and 7 are reserved on SH-3 (_PAGE_WT and _PAGE_SZ1 on SH-4).
 *
 * - Bit 1 is the SH-bit, but is unused on SH-3 due to an MMU bug (the
 *   hardware PTEL value can't have the SH-bit set when MMUCR.IX is set,
 *   which is the default in cpu-sh3/mmu_context.h:MMU_CONTROL_INIT).
 *
 *   In order to keep this relatively clean, do not use these for defining
 *   SH-3 specific flags until all of the other unused bits have been
 *   exhausted.
 *
 * - Bit 9 is reserved by everyone and used by _PAGE_PROTNONE.
 *
 * - Bits 10 and 11 are low bits of the PPN that are reserved on >= 4K pages.
 *   Bit 10 is used for _PAGE_ACCESSED, bit 11 remains unused.
 *
 * - Bits 31, 30, and 29 remain unused by everyone and can be used for future
 *   software flags, although care must be taken to update _PAGE_CLEAR_FLAGS.
 *
 * XXX: Leave the _PAGE_FILE and _PAGE_WT overhaul for a rainy day.
 *
 * SH-X2 MMUs and extended PTEs
 *
 * SH-X2 supports an extended mode TLB with split data arrays due to the
 * number of bits needed for PR and SZ (now EPR and ESZ) encodings. The PR and
 * SZ bit placeholders still exist in data array 1, but are implemented as
 * reserved bits, with the real logic existing in data array 2.
 *
 * The downside to this is that we can no longer fit everything in to a 32-bit
 * PTE encoding, so a 64-bit pte_t is necessary for these parts. On the plus
 * side, this gives us quite a few spare bits to play with for future usage.
 */
/* Legacy and compat mode bits */
#define	_PAGE_WT	0x001		/* WT-bit on SH-4, 0 on SH-3 */
#define _PAGE_HW_SHARED	0x002		/* SH-bit  : shared among processes */
#define _PAGE_DIRTY	0x004		/* D-bit   : page changed */
#define _PAGE_CACHABLE	0x008		/* C-bit   : cachable */
#ifndef CONFIG_X2TLB
# define _PAGE_SZ0	0x010		/* SZ0-bit : Size of page */
# define _PAGE_RW	0x020		/* PR0-bit : write access allowed */
# define _PAGE_USER	0x040		/* PR1-bit : user space access allowed*/
# define _PAGE_SZ1	0x080		/* SZ1-bit : Size of page (on SH-4) */
#endif
#define _PAGE_PRESENT	0x100		/* V-bit   : page is valid */
#define _PAGE_PROTNONE	0x200		/* software: if not present  */
#define _PAGE_ACCESSED	0x400		/* software: page referenced */
#define _PAGE_FILE	_PAGE_WT	/* software: pagecache or swap? */

/* Extended mode bits */
#define _PAGE_EXT_ESZ0		0x0010	/* ESZ0-bit: Size of page */
#define _PAGE_EXT_ESZ1		0x0020	/* ESZ1-bit: Size of page */
#define _PAGE_EXT_ESZ2		0x0040	/* ESZ2-bit: Size of page */
#define _PAGE_EXT_ESZ3		0x0080	/* ESZ3-bit: Size of page */

#define _PAGE_EXT_USER_EXEC	0x0100	/* EPR0-bit: User space executable */
#define _PAGE_EXT_USER_WRITE	0x0200	/* EPR1-bit: User space writable */
#define _PAGE_EXT_USER_READ	0x0400	/* EPR2-bit: User space readable */

#define _PAGE_EXT_KERN_EXEC	0x0800	/* EPR3-bit: Kernel space executable */
#define _PAGE_EXT_KERN_WRITE	0x1000	/* EPR4-bit: Kernel space writable */
#define _PAGE_EXT_KERN_READ	0x2000	/* EPR5-bit: Kernel space readable */

/* Wrapper for extended mode pgprot twiddling */
#ifdef CONFIG_X2TLB
# define _PAGE_EXT(x)		((unsigned long long)(x) << 32)
#else
# define _PAGE_EXT(x)		(0)
#endif

/* software: moves to PTEA.TC (Timing Control) */
#define _PAGE_PCC_AREA5	0x00000000	/* use BSC registers for area5 */
#define _PAGE_PCC_AREA6	0x80000000	/* use BSC registers for area6 */

/* software: moves to PTEA.SA[2:0] (Space Attributes) */
#define _PAGE_PCC_IODYN 0x00000001	/* IO space, dynamically sized bus */
#define _PAGE_PCC_IO8	0x20000000	/* IO space, 8 bit bus */
#define _PAGE_PCC_IO16	0x20000001	/* IO space, 16 bit bus */
#define _PAGE_PCC_COM8	0x40000000	/* Common Memory space, 8 bit bus */
#define _PAGE_PCC_COM16	0x40000001	/* Common Memory space, 16 bit bus */
#define _PAGE_PCC_ATR8	0x60000000	/* Attribute Memory space, 8 bit bus */
#define _PAGE_PCC_ATR16	0x60000001	/* Attribute Memory space, 6 bit bus */

/* Mask which drops unused bits from the PTEL value */
#ifdef CONFIG_CPU_SH3
#define _PAGE_CLEAR_FLAGS	(_PAGE_PROTNONE | _PAGE_ACCESSED| \
				 _PAGE_FILE	| _PAGE_SZ1	| \
				 _PAGE_HW_SHARED)
#else
#define _PAGE_CLEAR_FLAGS	(_PAGE_PROTNONE | _PAGE_ACCESSED | _PAGE_FILE)
#endif

#define _PAGE_FLAGS_HARDWARE_MASK	(0x1fffffff & ~(_PAGE_CLEAR_FLAGS))

/* Hardware flags, page size encoding */
#if defined(CONFIG_X2TLB)
# if defined(CONFIG_PAGE_SIZE_4KB)
#  define _PAGE_FLAGS_HARD	_PAGE_EXT(_PAGE_EXT_ESZ0)
# elif defined(CONFIG_PAGE_SIZE_8KB)
#  define _PAGE_FLAGS_HARD	_PAGE_EXT(_PAGE_EXT_ESZ1)
# elif defined(CONFIG_PAGE_SIZE_64KB)
#  define _PAGE_FLAGS_HARD	_PAGE_EXT(_PAGE_EXT_ESZ2)
# endif
#else
# if defined(CONFIG_PAGE_SIZE_4KB)
#  define _PAGE_FLAGS_HARD	_PAGE_SZ0
# elif defined(CONFIG_PAGE_SIZE_64KB)
#  define _PAGE_FLAGS_HARD	_PAGE_SZ1
# endif
#endif

#if defined(CONFIG_X2TLB)
# if defined(CONFIG_HUGETLB_PAGE_SIZE_64K)
#  define _PAGE_SZHUGE	(_PAGE_EXT_ESZ2)
# elif defined(CONFIG_HUGETLB_PAGE_SIZE_256K)
#  define _PAGE_SZHUGE	(_PAGE_EXT_ESZ0 | _PAGE_EXT_ESZ2)
# elif defined(CONFIG_HUGETLB_PAGE_SIZE_1MB)
#  define _PAGE_SZHUGE	(_PAGE_EXT_ESZ0 | _PAGE_EXT_ESZ1 | _PAGE_EXT_ESZ2)
# elif defined(CONFIG_HUGETLB_PAGE_SIZE_4MB)
#  define _PAGE_SZHUGE	(_PAGE_EXT_ESZ3)
# elif defined(CONFIG_HUGETLB_PAGE_SIZE_64MB)
#  define _PAGE_SZHUGE	(_PAGE_EXT_ESZ2 | _PAGE_EXT_ESZ3)
# endif
#else
# if defined(CONFIG_HUGETLB_PAGE_SIZE_64K)
#  define _PAGE_SZHUGE	(_PAGE_SZ1)
# elif defined(CONFIG_HUGETLB_PAGE_SIZE_1MB)
#  define _PAGE_SZHUGE	(_PAGE_SZ0 | _PAGE_SZ1)
# endif
#endif

/*
 * Stub out _PAGE_SZHUGE if we don't have a good definition for it,
 * to make pte_mkhuge() happy.
 */
#ifndef _PAGE_SZHUGE
# define _PAGE_SZHUGE	(_PAGE_FLAGS_HARD)
#endif

#define _PAGE_CHG_MASK \
	(PTE_MASK | _PAGE_ACCESSED | _PAGE_CACHABLE | _PAGE_DIRTY)

#ifndef __ASSEMBLY__

#if defined(CONFIG_X2TLB) /* SH-X2 TLB */
#define PAGE_NONE	__pgprot(_PAGE_PROTNONE | _PAGE_CACHABLE | \
				 _PAGE_ACCESSED | _PAGE_FLAGS_HARD)

#define PAGE_SHARED	__pgprot(_PAGE_PRESENT | _PAGE_ACCESSED | \
				 _PAGE_CACHABLE | _PAGE_FLAGS_HARD | \
				 _PAGE_EXT(_PAGE_EXT_USER_READ | \
					   _PAGE_EXT_USER_WRITE))

#define PAGE_EXECREAD	__pgprot(_PAGE_PRESENT | _PAGE_ACCESSED | \
				 _PAGE_CACHABLE | _PAGE_FLAGS_HARD | \
				 _PAGE_EXT(_PAGE_EXT_USER_EXEC | \
					   _PAGE_EXT_USER_READ))

#define PAGE_COPY	PAGE_EXECREAD

#define PAGE_READONLY	__pgprot(_PAGE_PRESENT | _PAGE_ACCESSED | \
				 _PAGE_CACHABLE | _PAGE_FLAGS_HARD | \
				 _PAGE_EXT(_PAGE_EXT_USER_READ))

#define PAGE_WRITEONLY	__pgprot(_PAGE_PRESENT | _PAGE_ACCESSED | \
				 _PAGE_CACHABLE | _PAGE_FLAGS_HARD | \
				 _PAGE_EXT(_PAGE_EXT_USER_WRITE))

#define PAGE_RWX	__pgprot(_PAGE_PRESENT | _PAGE_ACCESSED | \
				 _PAGE_CACHABLE | _PAGE_FLAGS_HARD | \
				 _PAGE_EXT(_PAGE_EXT_USER_WRITE | \
					   _PAGE_EXT_USER_READ  | \
					   _PAGE_EXT_USER_EXEC))

#define PAGE_KERNEL	__pgprot(_PAGE_PRESENT | _PAGE_CACHABLE | \
				 _PAGE_DIRTY | _PAGE_ACCESSED | \
				 _PAGE_HW_SHARED | _PAGE_FLAGS_HARD | \
				 _PAGE_EXT(_PAGE_EXT_KERN_READ | \
					   _PAGE_EXT_KERN_WRITE | \
					   _PAGE_EXT_KERN_EXEC))

#define PAGE_KERNEL_NOCACHE \
			__pgprot(_PAGE_PRESENT | _PAGE_DIRTY | \
				 _PAGE_ACCESSED | _PAGE_HW_SHARED | \
				 _PAGE_FLAGS_HARD | \
				 _PAGE_EXT(_PAGE_EXT_KERN_READ | \
					   _PAGE_EXT_KERN_WRITE | \
					   _PAGE_EXT_KERN_EXEC))

#define PAGE_KERNEL_RO	__pgprot(_PAGE_PRESENT | _PAGE_CACHABLE | \
				 _PAGE_DIRTY | _PAGE_ACCESSED | \
				 _PAGE_HW_SHARED | _PAGE_FLAGS_HARD | \
				 _PAGE_EXT(_PAGE_EXT_KERN_READ | \
					   _PAGE_EXT_KERN_EXEC))

#define PAGE_KERNEL_PCC(slot, type) \
			__pgprot(_PAGE_PRESENT | _PAGE_DIRTY | \
				 _PAGE_ACCESSED | _PAGE_FLAGS_HARD | \
				 _PAGE_EXT(_PAGE_EXT_KERN_READ | \
					   _PAGE_EXT_KERN_WRITE | \
					   _PAGE_EXT_KERN_EXEC) \
				 (slot ? _PAGE_PCC_AREA5 : _PAGE_PCC_AREA6) | \
				 (type))

#elif defined(CONFIG_MMU) /* SH-X TLB */
#define PAGE_NONE	__pgprot(_PAGE_PROTNONE | _PAGE_CACHABLE | \
				 _PAGE_ACCESSED | _PAGE_FLAGS_HARD)

#define PAGE_SHARED	__pgprot(_PAGE_PRESENT | _PAGE_RW | _PAGE_USER | \
				 _PAGE_CACHABLE | _PAGE_ACCESSED | \
				 _PAGE_FLAGS_HARD)

#define PAGE_COPY	__pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_CACHABLE | \
				 _PAGE_ACCESSED | _PAGE_FLAGS_HARD)

#define PAGE_READONLY	__pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_CACHABLE | \
				 _PAGE_ACCESSED | _PAGE_FLAGS_HARD)

#define PAGE_EXECREAD	PAGE_READONLY
#define PAGE_RWX	PAGE_SHARED
#define PAGE_WRITEONLY	PAGE_SHARED

#define PAGE_KERNEL	__pgprot(_PAGE_PRESENT | _PAGE_RW | _PAGE_CACHABLE | \
				 _PAGE_DIRTY | _PAGE_ACCESSED | \
				 _PAGE_HW_SHARED | _PAGE_FLAGS_HARD)

#define PAGE_KERNEL_NOCACHE \
			__pgprot(_PAGE_PRESENT | _PAGE_RW | _PAGE_DIRTY | \
				 _PAGE_ACCESSED | _PAGE_HW_SHARED | \
				 _PAGE_FLAGS_HARD)

#define PAGE_KERNEL_RO	__pgprot(_PAGE_PRESENT | _PAGE_CACHABLE | \
				 _PAGE_DIRTY | _PAGE_ACCESSED | \
				 _PAGE_HW_SHARED | _PAGE_FLAGS_HARD)

#define PAGE_KERNEL_PCC(slot, type) \
			__pgprot(_PAGE_PRESENT | _PAGE_RW | _PAGE_DIRTY | \
				 _PAGE_ACCESSED | _PAGE_FLAGS_HARD | \
				 (slot ? _PAGE_PCC_AREA5 : _PAGE_PCC_AREA6) | \
				 (type))
#else /* no mmu */
#define PAGE_NONE		__pgprot(0)
#define PAGE_SHARED		__pgprot(0)
#define PAGE_COPY		__pgprot(0)
#define PAGE_EXECREAD		__pgprot(0)
#define PAGE_RWX		__pgprot(0)
#define PAGE_READONLY		__pgprot(0)
#define PAGE_WRITEONLY		__pgprot(0)
#define PAGE_KERNEL		__pgprot(0)
#define PAGE_KERNEL_NOCACHE	__pgprot(0)
#define PAGE_KERNEL_RO		__pgprot(0)
#define PAGE_KERNEL_PCC		__pgprot(0)
#endif

#endif /* __ASSEMBLY__ */

/*
 * SH-X and lower (legacy) SuperH parts (SH-3, SH-4, some SH-4A) can't do page
 * protection for execute, and considers it the same as a read. Also, write
 * permission implies read permission. This is the closest we can get..
 *
 * SH-X2 (SH7785) and later parts take this to the opposite end of the extreme,
 * not only supporting separate execute, read, and write bits, but having
 * completely separate permission bits for user and kernel space.
 */
	 /*xwr*/
#define __P000	PAGE_NONE
#define __P001	PAGE_READONLY
#define __P010	PAGE_COPY
#define __P011	PAGE_COPY
#define __P100	PAGE_EXECREAD
#define __P101	PAGE_EXECREAD
#define __P110	PAGE_COPY
#define __P111	PAGE_COPY

#define __S000	PAGE_NONE
#define __S001	PAGE_READONLY
#define __S010	PAGE_WRITEONLY
#define __S011	PAGE_SHARED
#define __S100	PAGE_EXECREAD
#define __S101	PAGE_EXECREAD
#define __S110	PAGE_RWX
#define __S111	PAGE_RWX

#ifndef __ASSEMBLY__

/*
 * Certain architectures need to do special things when PTEs
 * within a page table are directly modified.  Thus, the following
 * hook is made available.
 */
#ifdef CONFIG_X2TLB
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;
}
#else
#define set_pte(pteptr, pteval) (*(pteptr) = pteval)
#endif

#define set_pte_at(mm,addr,ptep,pteval) set_pte(ptep,pteval)

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

#define pte_pfn(x)		((unsigned long)(((x).pte_low >> PAGE_SHIFT)))
#define pfn_pte(pfn, prot)	__pte(((pfn) << PAGE_SHIFT) | pgprot_val(prot))
#define pfn_pmd(pfn, prot)	__pmd(((pfn) << PAGE_SHIFT) | pgprot_val(prot))

#define pte_none(x)	(!pte_val(x))
#define pte_present(x)	(pte_val(x) & (_PAGE_PRESENT | _PAGE_PROTNONE))
#define pte_clear(mm,addr,xp) do { set_pte_at(mm, addr, xp, __pte(0)); } while (0)

#define pmd_none(x)	(!pmd_val(x))
#define pmd_present(x)	(pmd_val(x))
#define pmd_clear(xp)	do { set_pmd(xp, __pmd(0)); } while (0)
#define	pmd_bad(x)	(pmd_val(x) & ~PAGE_MASK)

#define pages_to_mb(x)	((x) >> (20-PAGE_SHIFT))
#define pte_page(x)	phys_to_page(pte_val(x)&PTE_PHYS_MASK)

/*
 * The following only work if pte_present() is true.
 * Undefined behaviour if not..
 */
#define pte_not_present(pte)	(!(pte_val(pte) & _PAGE_PRESENT))
#define pte_dirty(pte)		(pte_val(pte) & _PAGE_DIRTY)
#define pte_young(pte)		(pte_val(pte) & _PAGE_ACCESSED)
#define pte_file(pte)		(pte_val(pte) & _PAGE_FILE)

#ifdef CONFIG_X2TLB
#define pte_write(pte)		((pte).pte_high & _PAGE_EXT_USER_WRITE)
#else
#define pte_write(pte)		(pte_val(pte) & _PAGE_RW)
#endif

#define PTE_BIT_FUNC(h,fn,op) \
static inline pte_t pte_##fn(pte_t pte) { pte.pte_##h op; return pte; }

#ifdef CONFIG_X2TLB
/*
 * We cheat a bit in the SH-X2 TLB case. As the permission bits are
 * individually toggled (and user permissions are entirely decoupled from
 * kernel permissions), we attempt to couple them a bit more sanely here.
 */
PTE_BIT_FUNC(high, wrprotect, &= ~_PAGE_EXT_USER_WRITE);
PTE_BIT_FUNC(high, mkwrite, |= _PAGE_EXT_USER_WRITE | _PAGE_EXT_KERN_WRITE);
PTE_BIT_FUNC(high, mkhuge, |= _PAGE_SZHUGE);
#else
PTE_BIT_FUNC(low, wrprotect, &= ~_PAGE_RW);
PTE_BIT_FUNC(low, mkwrite, |= _PAGE_RW);
PTE_BIT_FUNC(low, mkhuge, |= _PAGE_SZHUGE);
#endif

PTE_BIT_FUNC(low, mkclean, &= ~_PAGE_DIRTY);
PTE_BIT_FUNC(low, mkdirty, |= _PAGE_DIRTY);
PTE_BIT_FUNC(low, mkold, &= ~_PAGE_ACCESSED);
PTE_BIT_FUNC(low, mkyoung, |= _PAGE_ACCESSED);

/*
 * Macro and implementation to make a page protection as uncachable.
 */
#define pgprot_noncached pgprot_noncached

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

	prot &= ~_PAGE_CACHABLE;
	return __pgprot(prot);
}

#define pgprot_writecombine(prot) __pgprot(pgprot_val(prot) & ~_PAGE_CACHABLE)

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

static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
{
	set_pte(&pte, __pte((pte_val(pte) & _PAGE_CHG_MASK) |
			    pgprot_val(newprot)));
	return pte;
}

#define pmd_page_vaddr(pmd)	pmd_val(pmd)
#define pmd_page(pmd)		(virt_to_page(pmd_val(pmd)))

/* to find an entry in a page-table-directory. */
#define pgd_index(address) (((address) >> PGDIR_SHIFT) & (PTRS_PER_PGD-1))
#define pgd_offset(mm, address) ((mm)->pgd+pgd_index(address))

/* to find an entry in a kernel page-table-directory */
#define pgd_offset_k(address) pgd_offset(&init_mm, address)

/* Find an entry in the third-level page table.. */
#define pte_index(address) \
		((address >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
#define pte_offset_kernel(dir, address) \
	((pte_t *) pmd_page_vaddr(*(dir)) + pte_index(address))
#define pte_offset_map(dir, address) pte_offset_kernel(dir, address)
#define pte_offset_map_nested(dir, address) pte_offset_kernel(dir, address)
#define pte_unmap(pte)		do { } while (0)
#define pte_unmap_nested(pte)	do { } while (0)

#ifdef CONFIG_X2TLB
#define pte_ERROR(e) \
	printk("%s:%d: bad pte %p(%08lx%08lx).\n", __FILE__, __LINE__, \
	       &(e), (e).pte_high, (e).pte_low)
#else
#define pte_ERROR(e) \
	printk("%s:%d: bad pte %08lx.\n", __FILE__, __LINE__, pte_val(e))
#endif

#define pgd_ERROR(e) \
	printk("%s:%d: bad pgd %08lx.\n", __FILE__, __LINE__, pgd_val(e))

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

/*
 * Encode and de-code a swap entry
 *
 * Constraints:
 *	_PAGE_FILE at bit 0
 *	_PAGE_PRESENT at bit 8
 *	_PAGE_PROTNONE at bit 9
 *
 * For the normal case, we encode the swap type into bits 0:7 and the
 * swap offset into bits 10:30. For the 64-bit PTE case, we keep the
 * preserved bits in the low 32-bits and use the upper 32 as the swap
 * offset (along with a 5-bit type), following the same approach as x86
 * PAE. This keeps the logic quite simple, and allows for a full 32
 * PTE_FILE_MAX_BITS, as opposed to the 29-bits we're constrained with
 * in the pte_low case.
 *
 * As is evident by the Alpha code, if we ever get a 64-bit unsigned
 * long (swp_entry_t) to match up with the 64-bit PTEs, this all becomes
 * much cleaner..
 *
 * NOTE: We should set ZEROs at the position of _PAGE_PRESENT
 *       and _PAGE_PROTNONE bits
 */
#ifdef CONFIG_X2TLB
#define __swp_type(x)			((x).val & 0x1f)
#define __swp_offset(x)			((x).val >> 5)
#define __swp_entry(type, offset)	((swp_entry_t){ (type) | (offset) << 5})
#define __pte_to_swp_entry(pte)		((swp_entry_t){ (pte).pte_high })
#define __swp_entry_to_pte(x)		((pte_t){ 0, (x).val })

/*
 * Encode and decode a nonlinear file mapping entry
 */
#define pte_to_pgoff(pte)		((pte).pte_high)
#define pgoff_to_pte(off)		((pte_t) { _PAGE_FILE, (off) })

#define PTE_FILE_MAX_BITS		32
#else
#define __swp_type(x)			((x).val & 0xff)
#define __swp_offset(x)			((x).val >> 10)
#define __swp_entry(type, offset)	((swp_entry_t){(type) | (offset) <<10})

#define __pte_to_swp_entry(pte)		((swp_entry_t) { pte_val(pte) >> 1 })
#define __swp_entry_to_pte(x)		((pte_t) { (x).val << 1 })

/*
 * Encode and decode a nonlinear file mapping entry
 */
#define PTE_FILE_MAX_BITS	29
#define pte_to_pgoff(pte)	(pte_val(pte) >> 1)
#define pgoff_to_pte(off)	((pte_t) { ((off) << 1) | _PAGE_FILE })
#endif

typedef pte_t *pte_addr_t;

#define kern_addr_valid(addr)	(1)

#define io_remap_pfn_range(vma, vaddr, pfn, size, prot)		\
		remap_pfn_range(vma, vaddr, pfn, size, prot)

struct mm_struct;

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

#ifndef CONFIG_MMU
extern unsigned int kobjsize(const void *objp);
#endif /* !CONFIG_MMU */

#if defined(CONFIG_CPU_SH4) || defined(CONFIG_SH7705_CACHE_32KB)
#define __HAVE_ARCH_PTEP_GET_AND_CLEAR
extern pte_t ptep_get_and_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep);
#endif

extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
extern void paging_init(void);

#include <asm-generic/pgtable.h>

#endif /* !__ASSEMBLY__ */
#endif /* __ASM_SH_PAGE_H */