xref: /openbmc/linux/arch/ia64/include/asm/pgtable.h (revision 6fa24b41)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _ASM_IA64_PGTABLE_H
3 #define _ASM_IA64_PGTABLE_H
4 
5 /*
6  * This file contains the functions and defines necessary to modify and use
7  * the IA-64 page table tree.
8  *
9  * This hopefully works with any (fixed) IA-64 page-size, as defined
10  * in <asm/page.h>.
11  *
12  * Copyright (C) 1998-2005 Hewlett-Packard Co
13  *	David Mosberger-Tang <davidm@hpl.hp.com>
14  */
15 
16 
17 #include <asm/mman.h>
18 #include <asm/page.h>
19 #include <asm/processor.h>
20 #include <asm/types.h>
21 
22 #define IA64_MAX_PHYS_BITS	50	/* max. number of physical address bits (architected) */
23 
24 /*
25  * First, define the various bits in a PTE.  Note that the PTE format
26  * matches the VHPT short format, the firt doubleword of the VHPD long
27  * format, and the first doubleword of the TLB insertion format.
28  */
29 #define _PAGE_P_BIT		0
30 #define _PAGE_A_BIT		5
31 #define _PAGE_D_BIT		6
32 
33 #define _PAGE_P			(1 << _PAGE_P_BIT)	/* page present bit */
34 #define _PAGE_MA_WB		(0x0 <<  2)	/* write back memory attribute */
35 #define _PAGE_MA_UC		(0x4 <<  2)	/* uncacheable memory attribute */
36 #define _PAGE_MA_UCE		(0x5 <<  2)	/* UC exported attribute */
37 #define _PAGE_MA_WC		(0x6 <<  2)	/* write coalescing memory attribute */
38 #define _PAGE_MA_NAT		(0x7 <<  2)	/* not-a-thing attribute */
39 #define _PAGE_MA_MASK		(0x7 <<  2)
40 #define _PAGE_PL_0		(0 <<  7)	/* privilege level 0 (kernel) */
41 #define _PAGE_PL_1		(1 <<  7)	/* privilege level 1 (unused) */
42 #define _PAGE_PL_2		(2 <<  7)	/* privilege level 2 (unused) */
43 #define _PAGE_PL_3		(3 <<  7)	/* privilege level 3 (user) */
44 #define _PAGE_PL_MASK		(3 <<  7)
45 #define _PAGE_AR_R		(0 <<  9)	/* read only */
46 #define _PAGE_AR_RX		(1 <<  9)	/* read & execute */
47 #define _PAGE_AR_RW		(2 <<  9)	/* read & write */
48 #define _PAGE_AR_RWX		(3 <<  9)	/* read, write & execute */
49 #define _PAGE_AR_R_RW		(4 <<  9)	/* read / read & write */
50 #define _PAGE_AR_RX_RWX		(5 <<  9)	/* read & exec / read, write & exec */
51 #define _PAGE_AR_RWX_RW		(6 <<  9)	/* read, write & exec / read & write */
52 #define _PAGE_AR_X_RX		(7 <<  9)	/* exec & promote / read & exec */
53 #define _PAGE_AR_MASK		(7 <<  9)
54 #define _PAGE_AR_SHIFT		9
55 #define _PAGE_A			(1 << _PAGE_A_BIT)	/* page accessed bit */
56 #define _PAGE_D			(1 << _PAGE_D_BIT)	/* page dirty bit */
57 #define _PAGE_PPN_MASK		(((__IA64_UL(1) << IA64_MAX_PHYS_BITS) - 1) & ~0xfffUL)
58 #define _PAGE_ED		(__IA64_UL(1) << 52)	/* exception deferral */
59 #define _PAGE_PROTNONE		(__IA64_UL(1) << 63)
60 
61 /* We borrow bit 7 to store the exclusive marker in swap PTEs. */
62 #define _PAGE_SWP_EXCLUSIVE	(1 << 7)
63 
64 #define _PFN_MASK		_PAGE_PPN_MASK
65 /* Mask of bits which may be changed by pte_modify(); the odd bits are there for _PAGE_PROTNONE */
66 #define _PAGE_CHG_MASK	(_PAGE_P | _PAGE_PROTNONE | _PAGE_PL_MASK | _PAGE_AR_MASK | _PAGE_ED)
67 
68 #define _PAGE_SIZE_4K	12
69 #define _PAGE_SIZE_8K	13
70 #define _PAGE_SIZE_16K	14
71 #define _PAGE_SIZE_64K	16
72 #define _PAGE_SIZE_256K	18
73 #define _PAGE_SIZE_1M	20
74 #define _PAGE_SIZE_4M	22
75 #define _PAGE_SIZE_16M	24
76 #define _PAGE_SIZE_64M	26
77 #define _PAGE_SIZE_256M	28
78 #define _PAGE_SIZE_1G	30
79 #define _PAGE_SIZE_4G	32
80 
81 #define __ACCESS_BITS		_PAGE_ED | _PAGE_A | _PAGE_P | _PAGE_MA_WB
82 #define __DIRTY_BITS_NO_ED	_PAGE_A | _PAGE_P | _PAGE_D | _PAGE_MA_WB
83 #define __DIRTY_BITS		_PAGE_ED | __DIRTY_BITS_NO_ED
84 
85 /*
86  * How many pointers will a page table level hold expressed in shift
87  */
88 #define PTRS_PER_PTD_SHIFT	(PAGE_SHIFT-3)
89 
90 /*
91  * Definitions for fourth level:
92  */
93 #define PTRS_PER_PTE	(__IA64_UL(1) << (PTRS_PER_PTD_SHIFT))
94 
95 /*
96  * Definitions for third level:
97  *
98  * PMD_SHIFT determines the size of the area a third-level page table
99  * can map.
100  */
101 #define PMD_SHIFT	(PAGE_SHIFT + (PTRS_PER_PTD_SHIFT))
102 #define PMD_SIZE	(1UL << PMD_SHIFT)
103 #define PMD_MASK	(~(PMD_SIZE-1))
104 #define PTRS_PER_PMD	(1UL << (PTRS_PER_PTD_SHIFT))
105 
106 #if CONFIG_PGTABLE_LEVELS == 4
107 /*
108  * Definitions for second level:
109  *
110  * PUD_SHIFT determines the size of the area a second-level page table
111  * can map.
112  */
113 #define PUD_SHIFT	(PMD_SHIFT + (PTRS_PER_PTD_SHIFT))
114 #define PUD_SIZE	(1UL << PUD_SHIFT)
115 #define PUD_MASK	(~(PUD_SIZE-1))
116 #define PTRS_PER_PUD	(1UL << (PTRS_PER_PTD_SHIFT))
117 #endif
118 
119 /*
120  * Definitions for first level:
121  *
122  * PGDIR_SHIFT determines what a first-level page table entry can map.
123  */
124 #if CONFIG_PGTABLE_LEVELS == 4
125 #define PGDIR_SHIFT		(PUD_SHIFT + (PTRS_PER_PTD_SHIFT))
126 #else
127 #define PGDIR_SHIFT		(PMD_SHIFT + (PTRS_PER_PTD_SHIFT))
128 #endif
129 #define PGDIR_SIZE		(__IA64_UL(1) << PGDIR_SHIFT)
130 #define PGDIR_MASK		(~(PGDIR_SIZE-1))
131 #define PTRS_PER_PGD_SHIFT	PTRS_PER_PTD_SHIFT
132 #define PTRS_PER_PGD		(1UL << PTRS_PER_PGD_SHIFT)
133 #define USER_PTRS_PER_PGD	(5*PTRS_PER_PGD/8)	/* regions 0-4 are user regions */
134 
135 /*
136  * All the normal masks have the "page accessed" bits on, as any time
137  * they are used, the page is accessed. They are cleared only by the
138  * page-out routines.
139  */
140 #define PAGE_NONE	__pgprot(_PAGE_PROTNONE | _PAGE_A)
141 #define PAGE_SHARED	__pgprot(__ACCESS_BITS | _PAGE_PL_3 | _PAGE_AR_RW)
142 #define PAGE_READONLY	__pgprot(__ACCESS_BITS | _PAGE_PL_3 | _PAGE_AR_R)
143 #define PAGE_COPY	__pgprot(__ACCESS_BITS | _PAGE_PL_3 | _PAGE_AR_R)
144 #define PAGE_COPY_EXEC	__pgprot(__ACCESS_BITS | _PAGE_PL_3 | _PAGE_AR_RX)
145 #define PAGE_GATE	__pgprot(__ACCESS_BITS | _PAGE_PL_0 | _PAGE_AR_X_RX)
146 #define PAGE_KERNEL	__pgprot(__DIRTY_BITS  | _PAGE_PL_0 | _PAGE_AR_RWX)
147 #define PAGE_KERNELRX	__pgprot(__ACCESS_BITS | _PAGE_PL_0 | _PAGE_AR_RX)
148 #define PAGE_KERNEL_UC	__pgprot(__DIRTY_BITS  | _PAGE_PL_0 | _PAGE_AR_RWX | \
149 				 _PAGE_MA_UC)
150 
151 # ifndef __ASSEMBLY__
152 
153 #include <linux/sched/mm.h>	/* for mm_struct */
154 #include <linux/bitops.h>
155 #include <asm/cacheflush.h>
156 #include <asm/mmu_context.h>
157 
158 /*
159  * Next come the mappings that determine how mmap() protection bits
160  * (PROT_EXEC, PROT_READ, PROT_WRITE, PROT_NONE) get implemented.  The
161  * _P version gets used for a private shared memory segment, the _S
162  * version gets used for a shared memory segment with MAP_SHARED on.
163  * In a private shared memory segment, we do a copy-on-write if a task
164  * attempts to write to the page.
165  */
166 	/* xwr */
167 #define pgd_ERROR(e)	printk("%s:%d: bad pgd %016lx.\n", __FILE__, __LINE__, pgd_val(e))
168 #if CONFIG_PGTABLE_LEVELS == 4
169 #define pud_ERROR(e)	printk("%s:%d: bad pud %016lx.\n", __FILE__, __LINE__, pud_val(e))
170 #endif
171 #define pmd_ERROR(e)	printk("%s:%d: bad pmd %016lx.\n", __FILE__, __LINE__, pmd_val(e))
172 #define pte_ERROR(e)	printk("%s:%d: bad pte %016lx.\n", __FILE__, __LINE__, pte_val(e))
173 
174 
175 /*
176  * Some definitions to translate between mem_map, PTEs, and page addresses:
177  */
178 
179 
180 /* Quick test to see if ADDR is a (potentially) valid physical address. */
181 static inline long
182 ia64_phys_addr_valid (unsigned long addr)
183 {
184 	return (addr & (local_cpu_data->unimpl_pa_mask)) == 0;
185 }
186 
187 /*
188  * Now come the defines and routines to manage and access the three-level
189  * page table.
190  */
191 
192 
193 #define VMALLOC_START		(RGN_BASE(RGN_GATE) + 0x200000000UL)
194 #if defined(CONFIG_SPARSEMEM) && defined(CONFIG_SPARSEMEM_VMEMMAP)
195 /* SPARSEMEM_VMEMMAP uses half of vmalloc... */
196 # define VMALLOC_END		(RGN_BASE(RGN_GATE) + (1UL << (4*PAGE_SHIFT - 10)))
197 # define vmemmap		((struct page *)VMALLOC_END)
198 #else
199 # define VMALLOC_END		(RGN_BASE(RGN_GATE) + (1UL << (4*PAGE_SHIFT - 9)))
200 #endif
201 
202 /* fs/proc/kcore.c */
203 #define	kc_vaddr_to_offset(v) ((v) - RGN_BASE(RGN_GATE))
204 #define	kc_offset_to_vaddr(o) ((o) + RGN_BASE(RGN_GATE))
205 
206 #define RGN_MAP_SHIFT (PGDIR_SHIFT + PTRS_PER_PGD_SHIFT - 3)
207 #define RGN_MAP_LIMIT	((1UL << RGN_MAP_SHIFT) - PAGE_SIZE)	/* per region addr limit */
208 
209 #define PFN_PTE_SHIFT	PAGE_SHIFT
210 /*
211  * Conversion functions: convert page frame number (pfn) and a protection value to a page
212  * table entry (pte).
213  */
214 #define pfn_pte(pfn, pgprot) \
215 ({ pte_t __pte; pte_val(__pte) = ((pfn) << PAGE_SHIFT) | pgprot_val(pgprot); __pte; })
216 
217 /* Extract pfn from pte.  */
218 #define pte_pfn(_pte)		((pte_val(_pte) & _PFN_MASK) >> PAGE_SHIFT)
219 
220 #define mk_pte(page, pgprot)	pfn_pte(page_to_pfn(page), (pgprot))
221 
222 /* This takes a physical page address that is used by the remapping functions */
223 #define mk_pte_phys(physpage, pgprot) \
224 ({ pte_t __pte; pte_val(__pte) = physpage + pgprot_val(pgprot); __pte; })
225 
226 #define pte_modify(_pte, newprot) \
227 	(__pte((pte_val(_pte) & ~_PAGE_CHG_MASK) | (pgprot_val(newprot) & _PAGE_CHG_MASK)))
228 
229 #define pte_none(pte) 			(!pte_val(pte))
230 #define pte_present(pte)		(pte_val(pte) & (_PAGE_P | _PAGE_PROTNONE))
231 #define pte_clear(mm,addr,pte)		(pte_val(*(pte)) = 0UL)
232 /* pte_page() returns the "struct page *" corresponding to the PTE: */
233 #define pte_page(pte)			virt_to_page(((pte_val(pte) & _PFN_MASK) + PAGE_OFFSET))
234 
235 #define pmd_none(pmd)			(!pmd_val(pmd))
236 #define pmd_bad(pmd)			(!ia64_phys_addr_valid(pmd_val(pmd)))
237 #define pmd_present(pmd)		(pmd_val(pmd) != 0UL)
238 #define pmd_clear(pmdp)			(pmd_val(*(pmdp)) = 0UL)
239 #define pmd_page_vaddr(pmd)		((unsigned long) __va(pmd_val(pmd) & _PFN_MASK))
240 #define pmd_pfn(pmd)			((pmd_val(pmd) & _PFN_MASK) >> PAGE_SHIFT)
241 #define pmd_page(pmd)			virt_to_page((pmd_val(pmd) + PAGE_OFFSET))
242 
243 #define pud_none(pud)			(!pud_val(pud))
244 #define pud_bad(pud)			(!ia64_phys_addr_valid(pud_val(pud)))
245 #define pud_present(pud)		(pud_val(pud) != 0UL)
246 #define pud_clear(pudp)			(pud_val(*(pudp)) = 0UL)
247 #define pud_pgtable(pud)		((pmd_t *) __va(pud_val(pud) & _PFN_MASK))
248 #define pud_page(pud)			virt_to_page((pud_val(pud) + PAGE_OFFSET))
249 
250 #if CONFIG_PGTABLE_LEVELS == 4
251 #define p4d_none(p4d)			(!p4d_val(p4d))
252 #define p4d_bad(p4d)			(!ia64_phys_addr_valid(p4d_val(p4d)))
253 #define p4d_present(p4d)		(p4d_val(p4d) != 0UL)
254 #define p4d_clear(p4dp)			(p4d_val(*(p4dp)) = 0UL)
255 #define p4d_pgtable(p4d)		((pud_t *) __va(p4d_val(p4d) & _PFN_MASK))
256 #define p4d_page(p4d)			virt_to_page((p4d_val(p4d) + PAGE_OFFSET))
257 #endif
258 
259 /*
260  * The following have defined behavior only work if pte_present() is true.
261  */
262 #define pte_write(pte)	((unsigned) (((pte_val(pte) & _PAGE_AR_MASK) >> _PAGE_AR_SHIFT) - 2) <= 4)
263 #define pte_exec(pte)		((pte_val(pte) & _PAGE_AR_RX) != 0)
264 #define pte_dirty(pte)		((pte_val(pte) & _PAGE_D) != 0)
265 #define pte_young(pte)		((pte_val(pte) & _PAGE_A) != 0)
266 
267 /*
268  * Note: we convert AR_RWX to AR_RX and AR_RW to AR_R by clearing the 2nd bit in the
269  * access rights:
270  */
271 #define pte_wrprotect(pte)	(__pte(pte_val(pte) & ~_PAGE_AR_RW))
272 #define pte_mkwrite_novma(pte)	(__pte(pte_val(pte) | _PAGE_AR_RW))
273 #define pte_mkold(pte)		(__pte(pte_val(pte) & ~_PAGE_A))
274 #define pte_mkyoung(pte)	(__pte(pte_val(pte) | _PAGE_A))
275 #define pte_mkclean(pte)	(__pte(pte_val(pte) & ~_PAGE_D))
276 #define pte_mkdirty(pte)	(__pte(pte_val(pte) | _PAGE_D))
277 #define pte_mkhuge(pte)		(__pte(pte_val(pte)))
278 
279 /*
280  * Because ia64's Icache and Dcache is not coherent (on a cpu), we need to
281  * sync icache and dcache when we insert *new* executable page.
282  *  __ia64_sync_icache_dcache() check Pg_arch_1 bit and flush icache
283  * if necessary.
284  *
285  *  set_pte() is also called by the kernel, but we can expect that the kernel
286  *  flushes icache explicitly if necessary.
287  */
288 #define pte_present_exec_user(pte)\
289 	((pte_val(pte) & (_PAGE_P | _PAGE_PL_MASK | _PAGE_AR_RX)) == \
290 		(_PAGE_P | _PAGE_PL_3 | _PAGE_AR_RX))
291 
292 extern void __ia64_sync_icache_dcache(pte_t pteval);
293 static inline void set_pte(pte_t *ptep, pte_t pteval)
294 {
295 	/* page is present && page is user  && page is executable
296 	 * && (page swapin or new page or page migration
297 	 *	|| copy_on_write with page copying.)
298 	 */
299 	if (pte_present_exec_user(pteval) &&
300 	    (!pte_present(*ptep) ||
301 		pte_pfn(*ptep) != pte_pfn(pteval)))
302 		/* load_module() calles flush_icache_range() explicitly*/
303 		__ia64_sync_icache_dcache(pteval);
304 	*ptep = pteval;
305 }
306 
307 /*
308  * Make page protection values cacheable, uncacheable, or write-
309  * combining.  Note that "protection" is really a misnomer here as the
310  * protection value contains the memory attribute bits, dirty bits, and
311  * various other bits as well.
312  */
313 #define pgprot_cacheable(prot)		__pgprot((pgprot_val(prot) & ~_PAGE_MA_MASK) | _PAGE_MA_WB)
314 #define pgprot_noncached(prot)		__pgprot((pgprot_val(prot) & ~_PAGE_MA_MASK) | _PAGE_MA_UC)
315 #define pgprot_writecombine(prot)	__pgprot((pgprot_val(prot) & ~_PAGE_MA_MASK) | _PAGE_MA_WC)
316 
317 struct file;
318 extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
319 				     unsigned long size, pgprot_t vma_prot);
320 #define __HAVE_PHYS_MEM_ACCESS_PROT
321 
322 static inline unsigned long
323 pgd_index (unsigned long address)
324 {
325 	unsigned long region = address >> 61;
326 	unsigned long l1index = (address >> PGDIR_SHIFT) & ((PTRS_PER_PGD >> 3) - 1);
327 
328 	return (region << (PAGE_SHIFT - 6)) | l1index;
329 }
330 #define pgd_index pgd_index
331 
332 /*
333  * In the kernel's mapped region we know everything is in region number 5, so
334  * as an optimisation its PGD already points to the area for that region.
335  * However, this also means that we cannot use pgd_index() and we must
336  * never add the region here.
337  */
338 #define pgd_offset_k(addr) \
339 	(init_mm.pgd + (((addr) >> PGDIR_SHIFT) & (PTRS_PER_PGD - 1)))
340 
341 /* Look up a pgd entry in the gate area.  On IA-64, the gate-area
342    resides in the kernel-mapped segment, hence we use pgd_offset_k()
343    here.  */
344 #define pgd_offset_gate(mm, addr)	pgd_offset_k(addr)
345 
346 /* atomic versions of the some PTE manipulations: */
347 
348 static inline int
349 ptep_test_and_clear_young (struct vm_area_struct *vma, unsigned long addr, pte_t *ptep)
350 {
351 #ifdef CONFIG_SMP
352 	if (!pte_young(*ptep))
353 		return 0;
354 	return test_and_clear_bit(_PAGE_A_BIT, ptep);
355 #else
356 	pte_t pte = *ptep;
357 	if (!pte_young(pte))
358 		return 0;
359 	set_pte_at(vma->vm_mm, addr, ptep, pte_mkold(pte));
360 	return 1;
361 #endif
362 }
363 
364 static inline pte_t
365 ptep_get_and_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
366 {
367 #ifdef CONFIG_SMP
368 	return __pte(xchg((long *) ptep, 0));
369 #else
370 	pte_t pte = *ptep;
371 	pte_clear(mm, addr, ptep);
372 	return pte;
373 #endif
374 }
375 
376 static inline void
377 ptep_set_wrprotect(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
378 {
379 #ifdef CONFIG_SMP
380 	unsigned long new, old;
381 
382 	do {
383 		old = pte_val(*ptep);
384 		new = pte_val(pte_wrprotect(__pte (old)));
385 	} while (cmpxchg((unsigned long *) ptep, old, new) != old);
386 #else
387 	pte_t old_pte = *ptep;
388 	set_pte_at(mm, addr, ptep, pte_wrprotect(old_pte));
389 #endif
390 }
391 
392 static inline int
393 pte_same (pte_t a, pte_t b)
394 {
395 	return pte_val(a) == pte_val(b);
396 }
397 
398 #define update_mmu_cache_range(vmf, vma, address, ptep, nr) do { } while (0)
399 #define update_mmu_cache(vma, address, ptep) do { } while (0)
400 
401 extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
402 extern void paging_init (void);
403 
404 /*
405  * Encode/decode swap entries and swap PTEs. Swap PTEs are all PTEs that
406  * are !pte_none() && !pte_present().
407  *
408  * Note: The macros below rely on the fact that MAX_SWAPFILES_SHIFT <= number of
409  *	 bits in the swap-type field of the swap pte.  It would be nice to
410  *	 enforce that, but we can't easily include <linux/swap.h> here.
411  *	 (Of course, better still would be to define MAX_SWAPFILES_SHIFT here...).
412  *
413  * Format of swap pte:
414  *	bit   0   : present bit (must be zero)
415  *	bits  1- 6: swap type
416  *	bit   7   : exclusive marker
417  *	bits  8-62: swap offset
418  *	bit  63   : _PAGE_PROTNONE bit
419  */
420 #define __swp_type(entry)		(((entry).val >> 1) & 0x3f)
421 #define __swp_offset(entry)		(((entry).val << 1) >> 9)
422 #define __swp_entry(type, offset)	((swp_entry_t) { ((type & 0x3f) << 1) | \
423 							 ((long) (offset) << 8) })
424 #define __pte_to_swp_entry(pte)		((swp_entry_t) { pte_val(pte) })
425 #define __swp_entry_to_pte(x)		((pte_t) { (x).val })
426 
427 static inline int pte_swp_exclusive(pte_t pte)
428 {
429 	return pte_val(pte) & _PAGE_SWP_EXCLUSIVE;
430 }
431 
432 static inline pte_t pte_swp_mkexclusive(pte_t pte)
433 {
434 	pte_val(pte) |= _PAGE_SWP_EXCLUSIVE;
435 	return pte;
436 }
437 
438 static inline pte_t pte_swp_clear_exclusive(pte_t pte)
439 {
440 	pte_val(pte) &= ~_PAGE_SWP_EXCLUSIVE;
441 	return pte;
442 }
443 
444 /*
445  * ZERO_PAGE is a global shared page that is always zero: used
446  * for zero-mapped memory areas etc..
447  */
448 extern unsigned long empty_zero_page[PAGE_SIZE/sizeof(unsigned long)];
449 extern struct page *zero_page_memmap_ptr;
450 #define ZERO_PAGE(vaddr) (zero_page_memmap_ptr)
451 
452 /* We provide our own get_unmapped_area to cope with VA holes for userland */
453 #define HAVE_ARCH_UNMAPPED_AREA
454 
455 #ifdef CONFIG_HUGETLB_PAGE
456 #define HUGETLB_PGDIR_SHIFT	(HPAGE_SHIFT + 2*(PAGE_SHIFT-3))
457 #define HUGETLB_PGDIR_SIZE	(__IA64_UL(1) << HUGETLB_PGDIR_SHIFT)
458 #define HUGETLB_PGDIR_MASK	(~(HUGETLB_PGDIR_SIZE-1))
459 #endif
460 
461 
462 #define __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
463 /*
464  * Update PTEP with ENTRY, which is guaranteed to be a less
465  * restrictive PTE.  That is, ENTRY may have the ACCESSED, DIRTY, and
466  * WRITABLE bits turned on, when the value at PTEP did not.  The
467  * WRITABLE bit may only be turned if SAFELY_WRITABLE is TRUE.
468  *
469  * SAFELY_WRITABLE is TRUE if we can update the value at PTEP without
470  * having to worry about races.  On SMP machines, there are only two
471  * cases where this is true:
472  *
473  *	(1) *PTEP has the PRESENT bit turned OFF
474  *	(2) ENTRY has the DIRTY bit turned ON
475  *
476  * On ia64, we could implement this routine with a cmpxchg()-loop
477  * which ORs in the _PAGE_A/_PAGE_D bit if they're set in ENTRY.
478  * However, like on x86, we can get a more streamlined version by
479  * observing that it is OK to drop ACCESSED bit updates when
480  * SAFELY_WRITABLE is FALSE.  Besides being rare, all that would do is
481  * result in an extra Access-bit fault, which would then turn on the
482  * ACCESSED bit in the low-level fault handler (iaccess_bit or
483  * daccess_bit in ivt.S).
484  */
485 #ifdef CONFIG_SMP
486 # define ptep_set_access_flags(__vma, __addr, __ptep, __entry, __safely_writable) \
487 ({									\
488 	int __changed = !pte_same(*(__ptep), __entry);			\
489 	if (__changed && __safely_writable) {				\
490 		set_pte(__ptep, __entry);				\
491 		flush_tlb_page(__vma, __addr);				\
492 	}								\
493 	__changed;							\
494 })
495 #else
496 # define ptep_set_access_flags(__vma, __addr, __ptep, __entry, __safely_writable) \
497 ({									\
498 	int __changed = !pte_same(*(__ptep), __entry);			\
499 	if (__changed) {						\
500 		set_pte_at((__vma)->vm_mm, (__addr), __ptep, __entry);	\
501 		flush_tlb_page(__vma, __addr);				\
502 	}								\
503 	__changed;							\
504 })
505 #endif
506 # endif /* !__ASSEMBLY__ */
507 
508 /*
509  * Identity-mapped regions use a large page size.  We'll call such large pages
510  * "granules".  If you can think of a better name that's unambiguous, let me
511  * know...
512  */
513 #if defined(CONFIG_IA64_GRANULE_64MB)
514 # define IA64_GRANULE_SHIFT	_PAGE_SIZE_64M
515 #elif defined(CONFIG_IA64_GRANULE_16MB)
516 # define IA64_GRANULE_SHIFT	_PAGE_SIZE_16M
517 #endif
518 #define IA64_GRANULE_SIZE	(1 << IA64_GRANULE_SHIFT)
519 /*
520  * log2() of the page size we use to map the kernel image (IA64_TR_KERNEL):
521  */
522 #define KERNEL_TR_PAGE_SHIFT	_PAGE_SIZE_64M
523 #define KERNEL_TR_PAGE_SIZE	(1 << KERNEL_TR_PAGE_SHIFT)
524 
525 /* These tell get_user_pages() that the first gate page is accessible from user-level.  */
526 #define FIXADDR_USER_START	GATE_ADDR
527 #ifdef HAVE_BUGGY_SEGREL
528 # define FIXADDR_USER_END	(GATE_ADDR + 2*PAGE_SIZE)
529 #else
530 # define FIXADDR_USER_END	(GATE_ADDR + 2*PERCPU_PAGE_SIZE)
531 #endif
532 
533 #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
534 #define __HAVE_ARCH_PTEP_GET_AND_CLEAR
535 #define __HAVE_ARCH_PTEP_SET_WRPROTECT
536 #define __HAVE_ARCH_PTE_SAME
537 #define __HAVE_ARCH_PGD_OFFSET_GATE
538 
539 
540 #if CONFIG_PGTABLE_LEVELS == 3
541 #include <asm-generic/pgtable-nopud.h>
542 #endif
543 #include <asm-generic/pgtable-nop4d.h>
544 
545 #endif /* _ASM_IA64_PGTABLE_H */
546