Home Home > GIT Browse
summaryrefslogtreecommitdiff
blob: 9f3ed9ee8f13e0e8feed6483e56b45a541ee7832 (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
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
#ifndef _ASM_IA64_PGTABLE_H
#define _ASM_IA64_PGTABLE_H

/*
 * This file contains the functions and defines necessary to modify and use
 * the IA-64 page table tree.
 *
 * This hopefully works with any (fixed) IA-64 page-size, as defined
 * in <asm/page.h>.
 *
 * Copyright (C) 1998-2005 Hewlett-Packard Co
 *	David Mosberger-Tang <davidm@hpl.hp.com>
 */


#include <asm/mman.h>
#include <asm/page.h>
#include <asm/processor.h>
#include <asm/types.h>

#define IA64_MAX_PHYS_BITS	50	/* max. number of physical address bits (architected) */

/*
 * First, define the various bits in a PTE.  Note that the PTE format
 * matches the VHPT short format, the firt doubleword of the VHPD long
 * format, and the first doubleword of the TLB insertion format.
 */
#define _PAGE_P_BIT		0
#define _PAGE_A_BIT		5
#define _PAGE_D_BIT		6

#define _PAGE_P			(1 << _PAGE_P_BIT)	/* page present bit */
#define _PAGE_MA_WB		(0x0 <<  2)	/* write back memory attribute */
#define _PAGE_MA_UC		(0x4 <<  2)	/* uncacheable memory attribute */
#define _PAGE_MA_UCE		(0x5 <<  2)	/* UC exported attribute */
#define _PAGE_MA_WC		(0x6 <<  2)	/* write coalescing memory attribute */
#define _PAGE_MA_NAT		(0x7 <<  2)	/* not-a-thing attribute */
#define _PAGE_MA_MASK		(0x7 <<  2)
#define _PAGE_PL_0		(0 <<  7)	/* privilege level 0 (kernel) */
#define _PAGE_PL_1		(1 <<  7)	/* privilege level 1 (unused) */
#define _PAGE_PL_2		(2 <<  7)	/* privilege level 2 (unused) */
#define _PAGE_PL_3		(3 <<  7)	/* privilege level 3 (user) */
#define _PAGE_PL_MASK		(3 <<  7)
#define _PAGE_AR_R		(0 <<  9)	/* read only */
#define _PAGE_AR_RX		(1 <<  9)	/* read & execute */
#define _PAGE_AR_RW		(2 <<  9)	/* read & write */
#define _PAGE_AR_RWX		(3 <<  9)	/* read, write & execute */
#define _PAGE_AR_R_RW		(4 <<  9)	/* read / read & write */
#define _PAGE_AR_RX_RWX		(5 <<  9)	/* read & exec / read, write & exec */
#define _PAGE_AR_RWX_RW		(6 <<  9)	/* read, write & exec / read & write */
#define _PAGE_AR_X_RX		(7 <<  9)	/* exec & promote / read & exec */
#define _PAGE_AR_MASK		(7 <<  9)
#define _PAGE_AR_SHIFT		9
#define _PAGE_A			(1 << _PAGE_A_BIT)	/* page accessed bit */
#define _PAGE_D			(1 << _PAGE_D_BIT)	/* page dirty bit */
#define _PAGE_PPN_MASK		(((__IA64_UL(1) << IA64_MAX_PHYS_BITS) - 1) & ~0xfffUL)
#define _PAGE_ED		(__IA64_UL(1) << 52)	/* exception deferral */
#define _PAGE_PROTNONE		(__IA64_UL(1) << 63)

#define _PFN_MASK		_PAGE_PPN_MASK
/* Mask of bits which may be changed by pte_modify(); the odd bits are there for _PAGE_PROTNONE */
#define _PAGE_CHG_MASK	(_PAGE_P | _PAGE_PROTNONE | _PAGE_PL_MASK | _PAGE_AR_MASK | _PAGE_ED)

#define _PAGE_SIZE_4K	12
#define _PAGE_SIZE_8K	13
#define _PAGE_SIZE_16K	14
#define _PAGE_SIZE_64K	16
#define _PAGE_SIZE_256K	18
#define _PAGE_SIZE_1M	20
#define _PAGE_SIZE_4M	22
#define _PAGE_SIZE_16M	24
#define _PAGE_SIZE_64M	26
#define _PAGE_SIZE_256M	28
#define _PAGE_SIZE_1G	30
#define _PAGE_SIZE_4G	32

#define __ACCESS_BITS		_PAGE_ED | _PAGE_A | _PAGE_P | _PAGE_MA_WB
#define __DIRTY_BITS_NO_ED	_PAGE_A | _PAGE_P | _PAGE_D | _PAGE_MA_WB
#define __DIRTY_BITS		_PAGE_ED | __DIRTY_BITS_NO_ED

/*
 * How many pointers will a page table level hold expressed in shift
 */
#define PTRS_PER_PTD_SHIFT	(PAGE_SHIFT-3)

/*
 * Definitions for fourth level:
 */
#define PTRS_PER_PTE	(__IA64_UL(1) << (PTRS_PER_PTD_SHIFT))

/*
 * Definitions for third level:
 *
 * PMD_SHIFT determines the size of the area a third-level page table
 * can map.
 */
#define PMD_SHIFT	(PAGE_SHIFT + (PTRS_PER_PTD_SHIFT))
#define PMD_SIZE	(1UL << PMD_SHIFT)
#define PMD_MASK	(~(PMD_SIZE-1))
#define PTRS_PER_PMD	(1UL << (PTRS_PER_PTD_SHIFT))

#if CONFIG_PGTABLE_LEVELS == 4
/*
 * Definitions for second level:
 *
 * PUD_SHIFT determines the size of the area a second-level page table
 * can map.
 */
#define PUD_SHIFT	(PMD_SHIFT + (PTRS_PER_PTD_SHIFT))
#define PUD_SIZE	(1UL << PUD_SHIFT)
#define PUD_MASK	(~(PUD_SIZE-1))
#define PTRS_PER_PUD	(1UL << (PTRS_PER_PTD_SHIFT))
#endif

/*
 * Definitions for first level:
 *
 * PGDIR_SHIFT determines what a first-level page table entry can map.
 */
#if CONFIG_PGTABLE_LEVELS == 4
#define PGDIR_SHIFT		(PUD_SHIFT + (PTRS_PER_PTD_SHIFT))
#else
#define PGDIR_SHIFT		(PMD_SHIFT + (PTRS_PER_PTD_SHIFT))
#endif
#define PGDIR_SIZE		(__IA64_UL(1) << PGDIR_SHIFT)
#define PGDIR_MASK		(~(PGDIR_SIZE-1))
#define PTRS_PER_PGD_SHIFT	PTRS_PER_PTD_SHIFT
#define PTRS_PER_PGD		(1UL << PTRS_PER_PGD_SHIFT)
#define USER_PTRS_PER_PGD	(5*PTRS_PER_PGD/8)	/* regions 0-4 are user regions */
#define FIRST_USER_ADDRESS	0UL

/*
 * All the normal masks have the "page accessed" bits on, as any time
 * they are used, the page is accessed. They are cleared only by the
 * page-out routines.
 */
#define PAGE_NONE	__pgprot(_PAGE_PROTNONE | _PAGE_A)
#define PAGE_SHARED	__pgprot(__ACCESS_BITS | _PAGE_PL_3 | _PAGE_AR_RW)
#define PAGE_READONLY	__pgprot(__ACCESS_BITS | _PAGE_PL_3 | _PAGE_AR_R)
#define PAGE_COPY	__pgprot(__ACCESS_BITS | _PAGE_PL_3 | _PAGE_AR_R)
#define PAGE_COPY_EXEC	__pgprot(__ACCESS_BITS | _PAGE_PL_3 | _PAGE_AR_RX)
#define PAGE_GATE	__pgprot(__ACCESS_BITS | _PAGE_PL_0 | _PAGE_AR_X_RX)
#define PAGE_KERNEL	__pgprot(__DIRTY_BITS  | _PAGE_PL_0 | _PAGE_AR_RWX)
#define PAGE_KERNELRX	__pgprot(__ACCESS_BITS | _PAGE_PL_0 | _PAGE_AR_RX)
#define PAGE_KERNEL_UC	__pgprot(__DIRTY_BITS  | _PAGE_PL_0 | _PAGE_AR_RWX | \
				 _PAGE_MA_UC)

# ifndef __ASSEMBLY__

#include <linux/sched.h>	/* for mm_struct */
#include <linux/bitops.h>
#include <asm/cacheflush.h>
#include <asm/mmu_context.h>

/*
 * Next come the mappings that determine how mmap() protection bits
 * (PROT_EXEC, PROT_READ, PROT_WRITE, PROT_NONE) get implemented.  The
 * _P version gets used for a private shared memory segment, the _S
 * version gets used for a shared memory segment with MAP_SHARED on.
 * In a private shared memory segment, we do a copy-on-write if a task
 * attempts to write to the page.
 */
	/* xwr */
#define __P000	PAGE_NONE
#define __P001	PAGE_READONLY
#define __P010	PAGE_READONLY	/* write to priv pg -> copy & make writable */
#define __P011	PAGE_READONLY	/* ditto */
#define __P100	__pgprot(__ACCESS_BITS | _PAGE_PL_3 | _PAGE_AR_X_RX)
#define __P101	__pgprot(__ACCESS_BITS | _PAGE_PL_3 | _PAGE_AR_RX)
#define __P110	PAGE_COPY_EXEC
#define __P111	PAGE_COPY_EXEC

#define __S000	PAGE_NONE
#define __S001	PAGE_READONLY
#define __S010	PAGE_SHARED	/* we don't have (and don't need) write-only */
#define __S011	PAGE_SHARED
#define __S100	__pgprot(__ACCESS_BITS | _PAGE_PL_3 | _PAGE_AR_X_RX)
#define __S101	__pgprot(__ACCESS_BITS | _PAGE_PL_3 | _PAGE_AR_RX)
#define __S110	__pgprot(__ACCESS_BITS | _PAGE_PL_3 | _PAGE_AR_RWX)
#define __S111	__pgprot(__ACCESS_BITS | _PAGE_PL_3 | _PAGE_AR_RWX)

#define pgd_ERROR(e)	printk("%s:%d: bad pgd %016lx.\n", __FILE__, __LINE__, pgd_val(e))
#if CONFIG_PGTABLE_LEVELS == 4
#define pud_ERROR(e)	printk("%s:%d: bad pud %016lx.\n", __FILE__, __LINE__, pud_val(e))
#endif
#define pmd_ERROR(e)	printk("%s:%d: bad pmd %016lx.\n", __FILE__, __LINE__, pmd_val(e))
#define pte_ERROR(e)	printk("%s:%d: bad pte %016lx.\n", __FILE__, __LINE__, pte_val(e))


/*
 * Some definitions to translate between mem_map, PTEs, and page addresses:
 */


/* Quick test to see if ADDR is a (potentially) valid physical address. */
static inline long
ia64_phys_addr_valid (unsigned long addr)
{
	return (addr & (local_cpu_data->unimpl_pa_mask)) == 0;
}

/*
 * kern_addr_valid(ADDR) tests if ADDR is pointing to valid kernel
 * memory.  For the return value to be meaningful, ADDR must be >=
 * PAGE_OFFSET.  This operation can be relatively expensive (e.g.,
 * require a hash-, or multi-level tree-lookup or something of that
 * sort) but it guarantees to return TRUE only if accessing the page
 * at that address does not cause an error.  Note that there may be
 * addresses for which kern_addr_valid() returns FALSE even though an
 * access would not cause an error (e.g., this is typically true for
 * memory mapped I/O regions.
 *
 * XXX Need to implement this for IA-64.
 */
#define kern_addr_valid(addr)	(1)


/*
 * Now come the defines and routines to manage and access the three-level
 * page table.
 */


#define VMALLOC_START		(RGN_BASE(RGN_GATE) + 0x200000000UL)
#ifdef CONFIG_VIRTUAL_MEM_MAP
# define VMALLOC_END_INIT	(RGN_BASE(RGN_GATE) + (1UL << (4*PAGE_SHIFT - 9)))
extern unsigned long VMALLOC_END;
#else
#if defined(CONFIG_SPARSEMEM) && defined(CONFIG_SPARSEMEM_VMEMMAP)
/* SPARSEMEM_VMEMMAP uses half of vmalloc... */
# define VMALLOC_END		(RGN_BASE(RGN_GATE) + (1UL << (4*PAGE_SHIFT - 10)))
# define vmemmap		((struct page *)VMALLOC_END)
#else
# define VMALLOC_END		(RGN_BASE(RGN_GATE) + (1UL << (4*PAGE_SHIFT - 9)))
#endif
#endif

/* fs/proc/kcore.c */
#define	kc_vaddr_to_offset(v) ((v) - RGN_BASE(RGN_GATE))
#define	kc_offset_to_vaddr(o) ((o) + RGN_BASE(RGN_GATE))

#define RGN_MAP_SHIFT (PGDIR_SHIFT + PTRS_PER_PGD_SHIFT - 3)
#define RGN_MAP_LIMIT	((1UL << RGN_MAP_SHIFT) - PAGE_SIZE)	/* per region addr limit */

/*
 * Conversion functions: convert page frame number (pfn) and a protection value to a page
 * table entry (pte).
 */
#define pfn_pte(pfn, pgprot) \
({ pte_t __pte; pte_val(__pte) = ((pfn) << PAGE_SHIFT) | pgprot_val(pgprot); __pte; })

/* Extract pfn from pte.  */
#define pte_pfn(_pte)		((pte_val(_pte) & _PFN_MASK) >> PAGE_SHIFT)

#define mk_pte(page, pgprot)	pfn_pte(page_to_pfn(page), (pgprot))

/* This takes a physical page address that is used by the remapping functions */
#define mk_pte_phys(physpage, pgprot) \
({ pte_t __pte; pte_val(__pte) = physpage + pgprot_val(pgprot); __pte; })

#define pte_modify(_pte, newprot) \
	(__pte((pte_val(_pte) & ~_PAGE_CHG_MASK) | (pgprot_val(newprot) & _PAGE_CHG_MASK)))

#define pte_none(pte) 			(!pte_val(pte))
#define pte_present(pte)		(pte_val(pte) & (_PAGE_P | _PAGE_PROTNONE))
#define pte_clear(mm,addr,pte)		(pte_val(*(pte)) = 0UL)
/* pte_page() returns the "struct page *" corresponding to the PTE: */
#define pte_page(pte)			virt_to_page(((pte_val(pte) & _PFN_MASK) + PAGE_OFFSET))

#define pmd_none(pmd)			(!pmd_val(pmd))
#define pmd_bad(pmd)			(!ia64_phys_addr_valid(pmd_val(pmd)))
#define pmd_present(pmd)		(pmd_val(pmd) != 0UL)
#define pmd_clear(pmdp)			(pmd_val(*(pmdp)) = 0UL)
#define pmd_page_vaddr(pmd)		((unsigned long) __va(pmd_val(pmd) & _PFN_MASK))
#define pmd_page(pmd)			virt_to_page((pmd_val(pmd) + PAGE_OFFSET))

#define pud_none(pud)			(!pud_val(pud))
#define pud_bad(pud)			(!ia64_phys_addr_valid(pud_val(pud)))
#define pud_present(pud)		(pud_val(pud) != 0UL)
#define pud_clear(pudp)			(pud_val(*(pudp)) = 0UL)
#define pud_page_vaddr(pud)		((unsigned long) __va(pud_val(pud) & _PFN_MASK))
#define pud_page(pud)			virt_to_page((pud_val(pud) + PAGE_OFFSET))

#if CONFIG_PGTABLE_LEVELS == 4
#define pgd_none(pgd)			(!pgd_val(pgd))
#define pgd_bad(pgd)			(!ia64_phys_addr_valid(pgd_val(pgd)))
#define pgd_present(pgd)		(pgd_val(pgd) != 0UL)
#define pgd_clear(pgdp)			(pgd_val(*(pgdp)) = 0UL)
#define pgd_page_vaddr(pgd)		((unsigned long) __va(pgd_val(pgd) & _PFN_MASK))
#define pgd_page(pgd)			virt_to_page((pgd_val(pgd) + PAGE_OFFSET))
#endif

/*
 * The following have defined behavior only work if pte_present() is true.
 */
#define pte_write(pte)	((unsigned) (((pte_val(pte) & _PAGE_AR_MASK) >> _PAGE_AR_SHIFT) - 2) <= 4)
#define pte_exec(pte)		((pte_val(pte) & _PAGE_AR_RX) != 0)
#define pte_dirty(pte)		((pte_val(pte) & _PAGE_D) != 0)
#define pte_young(pte)		((pte_val(pte) & _PAGE_A) != 0)
#define pte_special(pte)	0

/*
 * Note: we convert AR_RWX to AR_RX and AR_RW to AR_R by clearing the 2nd bit in the
 * access rights:
 */
#define pte_wrprotect(pte)	(__pte(pte_val(pte) & ~_PAGE_AR_RW))
#define pte_mkwrite(pte)	(__pte(pte_val(pte) | _PAGE_AR_RW))
#define pte_mkold(pte)		(__pte(pte_val(pte) & ~_PAGE_A))
#define pte_mkyoung(pte)	(__pte(pte_val(pte) | _PAGE_A))
#define pte_mkclean(pte)	(__pte(pte_val(pte) & ~_PAGE_D))
#define pte_mkdirty(pte)	(__pte(pte_val(pte) | _PAGE_D))
#define pte_mkhuge(pte)		(__pte(pte_val(pte)))
#define pte_mkspecial(pte)	(pte)

/*
 * Because ia64's Icache and Dcache is not coherent (on a cpu), we need to
 * sync icache and dcache when we insert *new* executable page.
 *  __ia64_sync_icache_dcache() check Pg_arch_1 bit and flush icache
 * if necessary.
 *
 *  set_pte() is also called by the kernel, but we can expect that the kernel
 *  flushes icache explicitly if necessary.
 */
#define pte_present_exec_user(pte)\
	((pte_val(pte) & (_PAGE_P | _PAGE_PL_MASK | _PAGE_AR_RX)) == \
		(_PAGE_P | _PAGE_PL_3 | _PAGE_AR_RX))

extern void __ia64_sync_icache_dcache(pte_t pteval);
static inline void set_pte(pte_t *ptep, pte_t pteval)
{
	/* page is present && page is user  && page is executable
	 * && (page swapin or new page or page migraton
	 *	|| copy_on_write with page copying.)
	 */
	if (pte_present_exec_user(pteval) &&
	    (!pte_present(*ptep) ||
		pte_pfn(*ptep) != pte_pfn(pteval)))
		/* load_module() calles flush_icache_range() explicitly*/
		__ia64_sync_icache_dcache(pteval);
	*ptep = pteval;
}

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

/*
 * Make page protection values cacheable, uncacheable, or write-
 * combining.  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_cacheable(prot)		__pgprot((pgprot_val(prot) & ~_PAGE_MA_MASK) | _PAGE_MA_WB)
#define pgprot_noncached(prot)		__pgprot((pgprot_val(prot) & ~_PAGE_MA_MASK) | _PAGE_MA_UC)
#define pgprot_writecombine(prot)	__pgprot((pgprot_val(prot) & ~_PAGE_MA_MASK) | _PAGE_MA_WC)

struct file;
extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
				     unsigned long size, pgprot_t vma_prot);
#define __HAVE_PHYS_MEM_ACCESS_PROT

static inline unsigned long
pgd_index (unsigned long address)
{
	unsigned long region = address >> 61;
	unsigned long l1index = (address >> PGDIR_SHIFT) & ((PTRS_PER_PGD >> 3) - 1);

	return (region << (PAGE_SHIFT - 6)) | l1index;
}

/* The offset in the 1-level directory is given by the 3 region bits
   (61..63) and the level-1 bits.  */
static inline pgd_t*
pgd_offset (const struct mm_struct *mm, unsigned long address)
{
	return mm->pgd + pgd_index(address);
}

/* In the kernel's mapped region we completely ignore the region number
   (since we know it's in region number 5). */
#define pgd_offset_k(addr) \
	(init_mm.pgd + (((addr) >> PGDIR_SHIFT) & (PTRS_PER_PGD - 1)))

/* Look up a pgd entry in the gate area.  On IA-64, the gate-area
   resides in the kernel-mapped segment, hence we use pgd_offset_k()
   here.  */
#define pgd_offset_gate(mm, addr)	pgd_offset_k(addr)

#if CONFIG_PGTABLE_LEVELS == 4
/* Find an entry in the second-level page table.. */
#define pud_offset(dir,addr) \
	((pud_t *) pgd_page_vaddr(*(dir)) + (((addr) >> PUD_SHIFT) & (PTRS_PER_PUD - 1)))
#endif

/* Find an entry in the third-level page table.. */
#define pmd_offset(dir,addr) \
	((pmd_t *) pud_page_vaddr(*(dir)) + (((addr) >> PMD_SHIFT) & (PTRS_PER_PMD - 1)))

/*
 * Find an entry in the third-level page table.  This looks more complicated than it
 * should be because some platforms place page tables in high memory.
 */
#define pte_index(addr)	 	(((addr) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
#define pte_offset_kernel(dir,addr)	((pte_t *) pmd_page_vaddr(*(dir)) + pte_index(addr))
#define pte_offset_map(dir,addr)	pte_offset_kernel(dir, addr)
#define pte_unmap(pte)			do { } while (0)

/* atomic versions of the some PTE manipulations: */

static inline int
ptep_test_and_clear_young (struct vm_area_struct *vma, unsigned long addr, pte_t *ptep)
{
#ifdef CONFIG_SMP
	if (!pte_young(*ptep))
		return 0;
	return test_and_clear_bit(_PAGE_A_BIT, ptep);
#else
	pte_t pte = *ptep;
	if (!pte_young(pte))
		return 0;
	set_pte_at(vma->vm_mm, addr, ptep, pte_mkold(pte));
	return 1;
#endif
}

static inline pte_t
ptep_get_and_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
{
#ifdef CONFIG_SMP
	return __pte(xchg((long *) ptep, 0));
#else
	pte_t pte = *ptep;
	pte_clear(mm, addr, ptep);
	return pte;
#endif
}

static inline void
ptep_set_wrprotect(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
{
#ifdef CONFIG_SMP
	unsigned long new, old;

	do {
		old = pte_val(*ptep);
		new = pte_val(pte_wrprotect(__pte (old)));
	} while (cmpxchg((unsigned long *) ptep, old, new) != old);
#else
	pte_t old_pte = *ptep;
	set_pte_at(mm, addr, ptep, pte_wrprotect(old_pte));
#endif
}

static inline int
pte_same (pte_t a, pte_t b)
{
	return pte_val(a) == pte_val(b);
}

#define update_mmu_cache(vma, address, ptep) do { } while (0)

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

/*
 * Note: The macros below rely on the fact that MAX_SWAPFILES_SHIFT <= number of
 *	 bits in the swap-type field of the swap pte.  It would be nice to
 *	 enforce that, but we can't easily include <linux/swap.h> here.
 *	 (Of course, better still would be to define MAX_SWAPFILES_SHIFT here...).
 *
 * Format of swap pte:
 *	bit   0   : present bit (must be zero)
 *	bits  1- 7: swap-type
 *	bits  8-62: swap offset
 *	bit  63   : _PAGE_PROTNONE bit
 */
#define __swp_type(entry)		(((entry).val >> 1) & 0x7f)
#define __swp_offset(entry)		(((entry).val << 1) >> 9)
#define __swp_entry(type,offset)	((swp_entry_t) { ((type) << 1) | ((long) (offset) << 8) })
#define __pte_to_swp_entry(pte)		((swp_entry_t) { pte_val(pte) })
#define __swp_entry_to_pte(x)		((pte_t) { (x).val })

/*
 * 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)];
extern struct page *zero_page_memmap_ptr;
#define ZERO_PAGE(vaddr) (zero_page_memmap_ptr)

/* We provide our own get_unmapped_area to cope with VA holes for userland */
#define HAVE_ARCH_UNMAPPED_AREA

#ifdef CONFIG_HUGETLB_PAGE
#define HUGETLB_PGDIR_SHIFT	(HPAGE_SHIFT + 2*(PAGE_SHIFT-3))
#define HUGETLB_PGDIR_SIZE	(__IA64_UL(1) << HUGETLB_PGDIR_SHIFT)
#define HUGETLB_PGDIR_MASK	(~(HUGETLB_PGDIR_SIZE-1))
#endif


#define __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
/*
 * Update PTEP with ENTRY, which is guaranteed to be a less
 * restrictive PTE.  That is, ENTRY may have the ACCESSED, DIRTY, and
 * WRITABLE bits turned on, when the value at PTEP did not.  The
 * WRITABLE bit may only be turned if SAFELY_WRITABLE is TRUE.
 *
 * SAFELY_WRITABLE is TRUE if we can update the value at PTEP without
 * having to worry about races.  On SMP machines, there are only two
 * cases where this is true:
 *
 *	(1) *PTEP has the PRESENT bit turned OFF
 *	(2) ENTRY has the DIRTY bit turned ON
 *
 * On ia64, we could implement this routine with a cmpxchg()-loop
 * which ORs in the _PAGE_A/_PAGE_D bit if they're set in ENTRY.
 * However, like on x86, we can get a more streamlined version by
 * observing that it is OK to drop ACCESSED bit updates when
 * SAFELY_WRITABLE is FALSE.  Besides being rare, all that would do is
 * result in an extra Access-bit fault, which would then turn on the
 * ACCESSED bit in the low-level fault handler (iaccess_bit or
 * daccess_bit in ivt.S).
 */
#ifdef CONFIG_SMP
# define ptep_set_access_flags(__vma, __addr, __ptep, __entry, __safely_writable) \
({									\
	int __changed = !pte_same(*(__ptep), __entry);			\
	if (__changed && __safely_writable) {				\
		set_pte(__ptep, __entry);				\
		flush_tlb_page(__vma, __addr);				\
	}								\
	__changed;							\
})
#else
# define ptep_set_access_flags(__vma, __addr, __ptep, __entry, __safely_writable) \
({									\
	int __changed = !pte_same(*(__ptep), __entry);			\
	if (__changed) {						\
		set_pte_at((__vma)->vm_mm, (__addr), __ptep, __entry);	\
		flush_tlb_page(__vma, __addr);				\
	}								\
	__changed;							\
})
#endif

#  ifdef CONFIG_VIRTUAL_MEM_MAP
  /* arch mem_map init routine is needed due to holes in a virtual mem_map */
#   define __HAVE_ARCH_MEMMAP_INIT
    extern void memmap_init (unsigned long size, int nid, unsigned long zone,
			     unsigned long start_pfn);
#  endif /* CONFIG_VIRTUAL_MEM_MAP */
# endif /* !__ASSEMBLY__ */

/*
 * Identity-mapped regions use a large page size.  We'll call such large pages
 * "granules".  If you can think of a better name that's unambiguous, let me
 * know...
 */
#if defined(CONFIG_IA64_GRANULE_64MB)
# define IA64_GRANULE_SHIFT	_PAGE_SIZE_64M
#elif defined(CONFIG_IA64_GRANULE_16MB)
# define IA64_GRANULE_SHIFT	_PAGE_SIZE_16M
#endif
#define IA64_GRANULE_SIZE	(1 << IA64_GRANULE_SHIFT)
/*
 * log2() of the page size we use to map the kernel image (IA64_TR_KERNEL):
 */
#define KERNEL_TR_PAGE_SHIFT	_PAGE_SIZE_64M
#define KERNEL_TR_PAGE_SIZE	(1 << KERNEL_TR_PAGE_SHIFT)

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

/* These tell get_user_pages() that the first gate page is accessible from user-level.  */
#define FIXADDR_USER_START	GATE_ADDR
#ifdef HAVE_BUGGY_SEGREL
# define FIXADDR_USER_END	(GATE_ADDR + 2*PAGE_SIZE)
#else
# define FIXADDR_USER_END	(GATE_ADDR + 2*PERCPU_PAGE_SIZE)
#endif

#define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
#define __HAVE_ARCH_PTEP_GET_AND_CLEAR
#define __HAVE_ARCH_PTEP_SET_WRPROTECT
#define __HAVE_ARCH_PTE_SAME
#define __HAVE_ARCH_PGD_OFFSET_GATE


#if CONFIG_PGTABLE_LEVELS == 3
#include <asm-generic/pgtable-nopud.h>
#endif
#include <asm-generic/pgtable.h>

#endif /* _ASM_IA64_PGTABLE_H */