xref: /openbmc/linux/arch/ia64/include/asm/pgtable.h (revision e15a5365)
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 #define _PFN_MASK		_PAGE_PPN_MASK
62 /* Mask of bits which may be changed by pte_modify(); the odd bits are there for _PAGE_PROTNONE */
63 #define _PAGE_CHG_MASK	(_PAGE_P | _PAGE_PROTNONE | _PAGE_PL_MASK | _PAGE_AR_MASK | _PAGE_ED)
64 
65 #define _PAGE_SIZE_4K	12
66 #define _PAGE_SIZE_8K	13
67 #define _PAGE_SIZE_16K	14
68 #define _PAGE_SIZE_64K	16
69 #define _PAGE_SIZE_256K	18
70 #define _PAGE_SIZE_1M	20
71 #define _PAGE_SIZE_4M	22
72 #define _PAGE_SIZE_16M	24
73 #define _PAGE_SIZE_64M	26
74 #define _PAGE_SIZE_256M	28
75 #define _PAGE_SIZE_1G	30
76 #define _PAGE_SIZE_4G	32
77 
78 #define __ACCESS_BITS		_PAGE_ED | _PAGE_A | _PAGE_P | _PAGE_MA_WB
79 #define __DIRTY_BITS_NO_ED	_PAGE_A | _PAGE_P | _PAGE_D | _PAGE_MA_WB
80 #define __DIRTY_BITS		_PAGE_ED | __DIRTY_BITS_NO_ED
81 
82 /*
83  * How many pointers will a page table level hold expressed in shift
84  */
85 #define PTRS_PER_PTD_SHIFT	(PAGE_SHIFT-3)
86 
87 /*
88  * Definitions for fourth level:
89  */
90 #define PTRS_PER_PTE	(__IA64_UL(1) << (PTRS_PER_PTD_SHIFT))
91 
92 /*
93  * Definitions for third level:
94  *
95  * PMD_SHIFT determines the size of the area a third-level page table
96  * can map.
97  */
98 #define PMD_SHIFT	(PAGE_SHIFT + (PTRS_PER_PTD_SHIFT))
99 #define PMD_SIZE	(1UL << PMD_SHIFT)
100 #define PMD_MASK	(~(PMD_SIZE-1))
101 #define PTRS_PER_PMD	(1UL << (PTRS_PER_PTD_SHIFT))
102 
103 #if CONFIG_PGTABLE_LEVELS == 4
104 /*
105  * Definitions for second level:
106  *
107  * PUD_SHIFT determines the size of the area a second-level page table
108  * can map.
109  */
110 #define PUD_SHIFT	(PMD_SHIFT + (PTRS_PER_PTD_SHIFT))
111 #define PUD_SIZE	(1UL << PUD_SHIFT)
112 #define PUD_MASK	(~(PUD_SIZE-1))
113 #define PTRS_PER_PUD	(1UL << (PTRS_PER_PTD_SHIFT))
114 #endif
115 
116 /*
117  * Definitions for first level:
118  *
119  * PGDIR_SHIFT determines what a first-level page table entry can map.
120  */
121 #if CONFIG_PGTABLE_LEVELS == 4
122 #define PGDIR_SHIFT		(PUD_SHIFT + (PTRS_PER_PTD_SHIFT))
123 #else
124 #define PGDIR_SHIFT		(PMD_SHIFT + (PTRS_PER_PTD_SHIFT))
125 #endif
126 #define PGDIR_SIZE		(__IA64_UL(1) << PGDIR_SHIFT)
127 #define PGDIR_MASK		(~(PGDIR_SIZE-1))
128 #define PTRS_PER_PGD_SHIFT	PTRS_PER_PTD_SHIFT
129 #define PTRS_PER_PGD		(1UL << PTRS_PER_PGD_SHIFT)
130 #define USER_PTRS_PER_PGD	(5*PTRS_PER_PGD/8)	/* regions 0-4 are user regions */
131 #define FIRST_USER_ADDRESS	0UL
132 
133 /*
134  * All the normal masks have the "page accessed" bits on, as any time
135  * they are used, the page is accessed. They are cleared only by the
136  * page-out routines.
137  */
138 #define PAGE_NONE	__pgprot(_PAGE_PROTNONE | _PAGE_A)
139 #define PAGE_SHARED	__pgprot(__ACCESS_BITS | _PAGE_PL_3 | _PAGE_AR_RW)
140 #define PAGE_READONLY	__pgprot(__ACCESS_BITS | _PAGE_PL_3 | _PAGE_AR_R)
141 #define PAGE_COPY	__pgprot(__ACCESS_BITS | _PAGE_PL_3 | _PAGE_AR_R)
142 #define PAGE_COPY_EXEC	__pgprot(__ACCESS_BITS | _PAGE_PL_3 | _PAGE_AR_RX)
143 #define PAGE_GATE	__pgprot(__ACCESS_BITS | _PAGE_PL_0 | _PAGE_AR_X_RX)
144 #define PAGE_KERNEL	__pgprot(__DIRTY_BITS  | _PAGE_PL_0 | _PAGE_AR_RWX)
145 #define PAGE_KERNELRX	__pgprot(__ACCESS_BITS | _PAGE_PL_0 | _PAGE_AR_RX)
146 #define PAGE_KERNEL_UC	__pgprot(__DIRTY_BITS  | _PAGE_PL_0 | _PAGE_AR_RWX | \
147 				 _PAGE_MA_UC)
148 
149 # ifndef __ASSEMBLY__
150 
151 #include <linux/sched/mm.h>	/* for mm_struct */
152 #include <linux/bitops.h>
153 #include <asm/cacheflush.h>
154 #include <asm/mmu_context.h>
155 
156 /*
157  * Next come the mappings that determine how mmap() protection bits
158  * (PROT_EXEC, PROT_READ, PROT_WRITE, PROT_NONE) get implemented.  The
159  * _P version gets used for a private shared memory segment, the _S
160  * version gets used for a shared memory segment with MAP_SHARED on.
161  * In a private shared memory segment, we do a copy-on-write if a task
162  * attempts to write to the page.
163  */
164 	/* xwr */
165 #define __P000	PAGE_NONE
166 #define __P001	PAGE_READONLY
167 #define __P010	PAGE_READONLY	/* write to priv pg -> copy & make writable */
168 #define __P011	PAGE_READONLY	/* ditto */
169 #define __P100	__pgprot(__ACCESS_BITS | _PAGE_PL_3 | _PAGE_AR_X_RX)
170 #define __P101	__pgprot(__ACCESS_BITS | _PAGE_PL_3 | _PAGE_AR_RX)
171 #define __P110	PAGE_COPY_EXEC
172 #define __P111	PAGE_COPY_EXEC
173 
174 #define __S000	PAGE_NONE
175 #define __S001	PAGE_READONLY
176 #define __S010	PAGE_SHARED	/* we don't have (and don't need) write-only */
177 #define __S011	PAGE_SHARED
178 #define __S100	__pgprot(__ACCESS_BITS | _PAGE_PL_3 | _PAGE_AR_X_RX)
179 #define __S101	__pgprot(__ACCESS_BITS | _PAGE_PL_3 | _PAGE_AR_RX)
180 #define __S110	__pgprot(__ACCESS_BITS | _PAGE_PL_3 | _PAGE_AR_RWX)
181 #define __S111	__pgprot(__ACCESS_BITS | _PAGE_PL_3 | _PAGE_AR_RWX)
182 
183 #define pgd_ERROR(e)	printk("%s:%d: bad pgd %016lx.\n", __FILE__, __LINE__, pgd_val(e))
184 #if CONFIG_PGTABLE_LEVELS == 4
185 #define pud_ERROR(e)	printk("%s:%d: bad pud %016lx.\n", __FILE__, __LINE__, pud_val(e))
186 #endif
187 #define pmd_ERROR(e)	printk("%s:%d: bad pmd %016lx.\n", __FILE__, __LINE__, pmd_val(e))
188 #define pte_ERROR(e)	printk("%s:%d: bad pte %016lx.\n", __FILE__, __LINE__, pte_val(e))
189 
190 
191 /*
192  * Some definitions to translate between mem_map, PTEs, and page addresses:
193  */
194 
195 
196 /* Quick test to see if ADDR is a (potentially) valid physical address. */
197 static inline long
198 ia64_phys_addr_valid (unsigned long addr)
199 {
200 	return (addr & (local_cpu_data->unimpl_pa_mask)) == 0;
201 }
202 
203 /*
204  * kern_addr_valid(ADDR) tests if ADDR is pointing to valid kernel
205  * memory.  For the return value to be meaningful, ADDR must be >=
206  * PAGE_OFFSET.  This operation can be relatively expensive (e.g.,
207  * require a hash-, or multi-level tree-lookup or something of that
208  * sort) but it guarantees to return TRUE only if accessing the page
209  * at that address does not cause an error.  Note that there may be
210  * addresses for which kern_addr_valid() returns FALSE even though an
211  * access would not cause an error (e.g., this is typically true for
212  * memory mapped I/O regions.
213  *
214  * XXX Need to implement this for IA-64.
215  */
216 #define kern_addr_valid(addr)	(1)
217 
218 
219 /*
220  * Now come the defines and routines to manage and access the three-level
221  * page table.
222  */
223 
224 
225 #define VMALLOC_START		(RGN_BASE(RGN_GATE) + 0x200000000UL)
226 #ifdef CONFIG_VIRTUAL_MEM_MAP
227 # define VMALLOC_END_INIT	(RGN_BASE(RGN_GATE) + (1UL << (4*PAGE_SHIFT - 9)))
228 extern unsigned long VMALLOC_END;
229 #else
230 #if defined(CONFIG_SPARSEMEM) && defined(CONFIG_SPARSEMEM_VMEMMAP)
231 /* SPARSEMEM_VMEMMAP uses half of vmalloc... */
232 # define VMALLOC_END		(RGN_BASE(RGN_GATE) + (1UL << (4*PAGE_SHIFT - 10)))
233 # define vmemmap		((struct page *)VMALLOC_END)
234 #else
235 # define VMALLOC_END		(RGN_BASE(RGN_GATE) + (1UL << (4*PAGE_SHIFT - 9)))
236 #endif
237 #endif
238 
239 /* fs/proc/kcore.c */
240 #define	kc_vaddr_to_offset(v) ((v) - RGN_BASE(RGN_GATE))
241 #define	kc_offset_to_vaddr(o) ((o) + RGN_BASE(RGN_GATE))
242 
243 #define RGN_MAP_SHIFT (PGDIR_SHIFT + PTRS_PER_PGD_SHIFT - 3)
244 #define RGN_MAP_LIMIT	((1UL << RGN_MAP_SHIFT) - PAGE_SIZE)	/* per region addr limit */
245 
246 /*
247  * Conversion functions: convert page frame number (pfn) and a protection value to a page
248  * table entry (pte).
249  */
250 #define pfn_pte(pfn, pgprot) \
251 ({ pte_t __pte; pte_val(__pte) = ((pfn) << PAGE_SHIFT) | pgprot_val(pgprot); __pte; })
252 
253 /* Extract pfn from pte.  */
254 #define pte_pfn(_pte)		((pte_val(_pte) & _PFN_MASK) >> PAGE_SHIFT)
255 
256 #define mk_pte(page, pgprot)	pfn_pte(page_to_pfn(page), (pgprot))
257 
258 /* This takes a physical page address that is used by the remapping functions */
259 #define mk_pte_phys(physpage, pgprot) \
260 ({ pte_t __pte; pte_val(__pte) = physpage + pgprot_val(pgprot); __pte; })
261 
262 #define pte_modify(_pte, newprot) \
263 	(__pte((pte_val(_pte) & ~_PAGE_CHG_MASK) | (pgprot_val(newprot) & _PAGE_CHG_MASK)))
264 
265 #define pte_none(pte) 			(!pte_val(pte))
266 #define pte_present(pte)		(pte_val(pte) & (_PAGE_P | _PAGE_PROTNONE))
267 #define pte_clear(mm,addr,pte)		(pte_val(*(pte)) = 0UL)
268 /* pte_page() returns the "struct page *" corresponding to the PTE: */
269 #define pte_page(pte)			virt_to_page(((pte_val(pte) & _PFN_MASK) + PAGE_OFFSET))
270 
271 #define pmd_none(pmd)			(!pmd_val(pmd))
272 #define pmd_bad(pmd)			(!ia64_phys_addr_valid(pmd_val(pmd)))
273 #define pmd_present(pmd)		(pmd_val(pmd) != 0UL)
274 #define pmd_clear(pmdp)			(pmd_val(*(pmdp)) = 0UL)
275 #define pmd_page_vaddr(pmd)		((unsigned long) __va(pmd_val(pmd) & _PFN_MASK))
276 #define pmd_page(pmd)			virt_to_page((pmd_val(pmd) + PAGE_OFFSET))
277 
278 #define pud_none(pud)			(!pud_val(pud))
279 #define pud_bad(pud)			(!ia64_phys_addr_valid(pud_val(pud)))
280 #define pud_present(pud)		(pud_val(pud) != 0UL)
281 #define pud_clear(pudp)			(pud_val(*(pudp)) = 0UL)
282 #define pud_page_vaddr(pud)		((unsigned long) __va(pud_val(pud) & _PFN_MASK))
283 #define pud_page(pud)			virt_to_page((pud_val(pud) + PAGE_OFFSET))
284 
285 #if CONFIG_PGTABLE_LEVELS == 4
286 #define p4d_none(p4d)			(!p4d_val(p4d))
287 #define p4d_bad(p4d)			(!ia64_phys_addr_valid(p4d_val(p4d)))
288 #define p4d_present(p4d)		(p4d_val(p4d) != 0UL)
289 #define p4d_clear(p4dp)			(p4d_val(*(p4dp)) = 0UL)
290 #define p4d_page_vaddr(p4d)		((unsigned long) __va(p4d_val(p4d) & _PFN_MASK))
291 #define p4d_page(p4d)			virt_to_page((p4d_val(p4d) + PAGE_OFFSET))
292 #endif
293 
294 /*
295  * The following have defined behavior only work if pte_present() is true.
296  */
297 #define pte_write(pte)	((unsigned) (((pte_val(pte) & _PAGE_AR_MASK) >> _PAGE_AR_SHIFT) - 2) <= 4)
298 #define pte_exec(pte)		((pte_val(pte) & _PAGE_AR_RX) != 0)
299 #define pte_dirty(pte)		((pte_val(pte) & _PAGE_D) != 0)
300 #define pte_young(pte)		((pte_val(pte) & _PAGE_A) != 0)
301 
302 /*
303  * Note: we convert AR_RWX to AR_RX and AR_RW to AR_R by clearing the 2nd bit in the
304  * access rights:
305  */
306 #define pte_wrprotect(pte)	(__pte(pte_val(pte) & ~_PAGE_AR_RW))
307 #define pte_mkwrite(pte)	(__pte(pte_val(pte) | _PAGE_AR_RW))
308 #define pte_mkold(pte)		(__pte(pte_val(pte) & ~_PAGE_A))
309 #define pte_mkyoung(pte)	(__pte(pte_val(pte) | _PAGE_A))
310 #define pte_mkclean(pte)	(__pte(pte_val(pte) & ~_PAGE_D))
311 #define pte_mkdirty(pte)	(__pte(pte_val(pte) | _PAGE_D))
312 #define pte_mkhuge(pte)		(__pte(pte_val(pte)))
313 
314 /*
315  * Because ia64's Icache and Dcache is not coherent (on a cpu), we need to
316  * sync icache and dcache when we insert *new* executable page.
317  *  __ia64_sync_icache_dcache() check Pg_arch_1 bit and flush icache
318  * if necessary.
319  *
320  *  set_pte() is also called by the kernel, but we can expect that the kernel
321  *  flushes icache explicitly if necessary.
322  */
323 #define pte_present_exec_user(pte)\
324 	((pte_val(pte) & (_PAGE_P | _PAGE_PL_MASK | _PAGE_AR_RX)) == \
325 		(_PAGE_P | _PAGE_PL_3 | _PAGE_AR_RX))
326 
327 extern void __ia64_sync_icache_dcache(pte_t pteval);
328 static inline void set_pte(pte_t *ptep, pte_t pteval)
329 {
330 	/* page is present && page is user  && page is executable
331 	 * && (page swapin or new page or page migraton
332 	 *	|| copy_on_write with page copying.)
333 	 */
334 	if (pte_present_exec_user(pteval) &&
335 	    (!pte_present(*ptep) ||
336 		pte_pfn(*ptep) != pte_pfn(pteval)))
337 		/* load_module() calles flush_icache_range() explicitly*/
338 		__ia64_sync_icache_dcache(pteval);
339 	*ptep = pteval;
340 }
341 
342 #define set_pte_at(mm,addr,ptep,pteval) set_pte(ptep,pteval)
343 
344 /*
345  * Make page protection values cacheable, uncacheable, or write-
346  * combining.  Note that "protection" is really a misnomer here as the
347  * protection value contains the memory attribute bits, dirty bits, and
348  * various other bits as well.
349  */
350 #define pgprot_cacheable(prot)		__pgprot((pgprot_val(prot) & ~_PAGE_MA_MASK) | _PAGE_MA_WB)
351 #define pgprot_noncached(prot)		__pgprot((pgprot_val(prot) & ~_PAGE_MA_MASK) | _PAGE_MA_UC)
352 #define pgprot_writecombine(prot)	__pgprot((pgprot_val(prot) & ~_PAGE_MA_MASK) | _PAGE_MA_WC)
353 
354 struct file;
355 extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
356 				     unsigned long size, pgprot_t vma_prot);
357 #define __HAVE_PHYS_MEM_ACCESS_PROT
358 
359 static inline unsigned long
360 pgd_index (unsigned long address)
361 {
362 	unsigned long region = address >> 61;
363 	unsigned long l1index = (address >> PGDIR_SHIFT) & ((PTRS_PER_PGD >> 3) - 1);
364 
365 	return (region << (PAGE_SHIFT - 6)) | l1index;
366 }
367 #define pgd_index pgd_index
368 
369 /*
370  * In the kernel's mapped region we know everything is in region number 5, so
371  * as an optimisation its PGD already points to the area for that region.
372  * However, this also means that we cannot use pgd_index() and we must
373  * never add the region here.
374  */
375 #define pgd_offset_k(addr) \
376 	(init_mm.pgd + (((addr) >> PGDIR_SHIFT) & (PTRS_PER_PGD - 1)))
377 
378 /* Look up a pgd entry in the gate area.  On IA-64, the gate-area
379    resides in the kernel-mapped segment, hence we use pgd_offset_k()
380    here.  */
381 #define pgd_offset_gate(mm, addr)	pgd_offset_k(addr)
382 
383 /* atomic versions of the some PTE manipulations: */
384 
385 static inline int
386 ptep_test_and_clear_young (struct vm_area_struct *vma, unsigned long addr, pte_t *ptep)
387 {
388 #ifdef CONFIG_SMP
389 	if (!pte_young(*ptep))
390 		return 0;
391 	return test_and_clear_bit(_PAGE_A_BIT, ptep);
392 #else
393 	pte_t pte = *ptep;
394 	if (!pte_young(pte))
395 		return 0;
396 	set_pte_at(vma->vm_mm, addr, ptep, pte_mkold(pte));
397 	return 1;
398 #endif
399 }
400 
401 static inline pte_t
402 ptep_get_and_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
403 {
404 #ifdef CONFIG_SMP
405 	return __pte(xchg((long *) ptep, 0));
406 #else
407 	pte_t pte = *ptep;
408 	pte_clear(mm, addr, ptep);
409 	return pte;
410 #endif
411 }
412 
413 static inline void
414 ptep_set_wrprotect(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
415 {
416 #ifdef CONFIG_SMP
417 	unsigned long new, old;
418 
419 	do {
420 		old = pte_val(*ptep);
421 		new = pte_val(pte_wrprotect(__pte (old)));
422 	} while (cmpxchg((unsigned long *) ptep, old, new) != old);
423 #else
424 	pte_t old_pte = *ptep;
425 	set_pte_at(mm, addr, ptep, pte_wrprotect(old_pte));
426 #endif
427 }
428 
429 static inline int
430 pte_same (pte_t a, pte_t b)
431 {
432 	return pte_val(a) == pte_val(b);
433 }
434 
435 #define update_mmu_cache(vma, address, ptep) do { } while (0)
436 
437 extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
438 extern void paging_init (void);
439 
440 /*
441  * Note: The macros below rely on the fact that MAX_SWAPFILES_SHIFT <= number of
442  *	 bits in the swap-type field of the swap pte.  It would be nice to
443  *	 enforce that, but we can't easily include <linux/swap.h> here.
444  *	 (Of course, better still would be to define MAX_SWAPFILES_SHIFT here...).
445  *
446  * Format of swap pte:
447  *	bit   0   : present bit (must be zero)
448  *	bits  1- 7: swap-type
449  *	bits  8-62: swap offset
450  *	bit  63   : _PAGE_PROTNONE bit
451  */
452 #define __swp_type(entry)		(((entry).val >> 1) & 0x7f)
453 #define __swp_offset(entry)		(((entry).val << 1) >> 9)
454 #define __swp_entry(type,offset)	((swp_entry_t) { ((type) << 1) | ((long) (offset) << 8) })
455 #define __pte_to_swp_entry(pte)		((swp_entry_t) { pte_val(pte) })
456 #define __swp_entry_to_pte(x)		((pte_t) { (x).val })
457 
458 /*
459  * ZERO_PAGE is a global shared page that is always zero: used
460  * for zero-mapped memory areas etc..
461  */
462 extern unsigned long empty_zero_page[PAGE_SIZE/sizeof(unsigned long)];
463 extern struct page *zero_page_memmap_ptr;
464 #define ZERO_PAGE(vaddr) (zero_page_memmap_ptr)
465 
466 /* We provide our own get_unmapped_area to cope with VA holes for userland */
467 #define HAVE_ARCH_UNMAPPED_AREA
468 
469 #ifdef CONFIG_HUGETLB_PAGE
470 #define HUGETLB_PGDIR_SHIFT	(HPAGE_SHIFT + 2*(PAGE_SHIFT-3))
471 #define HUGETLB_PGDIR_SIZE	(__IA64_UL(1) << HUGETLB_PGDIR_SHIFT)
472 #define HUGETLB_PGDIR_MASK	(~(HUGETLB_PGDIR_SIZE-1))
473 #endif
474 
475 
476 #define __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
477 /*
478  * Update PTEP with ENTRY, which is guaranteed to be a less
479  * restrictive PTE.  That is, ENTRY may have the ACCESSED, DIRTY, and
480  * WRITABLE bits turned on, when the value at PTEP did not.  The
481  * WRITABLE bit may only be turned if SAFELY_WRITABLE is TRUE.
482  *
483  * SAFELY_WRITABLE is TRUE if we can update the value at PTEP without
484  * having to worry about races.  On SMP machines, there are only two
485  * cases where this is true:
486  *
487  *	(1) *PTEP has the PRESENT bit turned OFF
488  *	(2) ENTRY has the DIRTY bit turned ON
489  *
490  * On ia64, we could implement this routine with a cmpxchg()-loop
491  * which ORs in the _PAGE_A/_PAGE_D bit if they're set in ENTRY.
492  * However, like on x86, we can get a more streamlined version by
493  * observing that it is OK to drop ACCESSED bit updates when
494  * SAFELY_WRITABLE is FALSE.  Besides being rare, all that would do is
495  * result in an extra Access-bit fault, which would then turn on the
496  * ACCESSED bit in the low-level fault handler (iaccess_bit or
497  * daccess_bit in ivt.S).
498  */
499 #ifdef CONFIG_SMP
500 # define ptep_set_access_flags(__vma, __addr, __ptep, __entry, __safely_writable) \
501 ({									\
502 	int __changed = !pte_same(*(__ptep), __entry);			\
503 	if (__changed && __safely_writable) {				\
504 		set_pte(__ptep, __entry);				\
505 		flush_tlb_page(__vma, __addr);				\
506 	}								\
507 	__changed;							\
508 })
509 #else
510 # define ptep_set_access_flags(__vma, __addr, __ptep, __entry, __safely_writable) \
511 ({									\
512 	int __changed = !pte_same(*(__ptep), __entry);			\
513 	if (__changed) {						\
514 		set_pte_at((__vma)->vm_mm, (__addr), __ptep, __entry);	\
515 		flush_tlb_page(__vma, __addr);				\
516 	}								\
517 	__changed;							\
518 })
519 #endif
520 
521 #  ifdef CONFIG_VIRTUAL_MEM_MAP
522   /* arch mem_map init routine is needed due to holes in a virtual mem_map */
523     extern void memmap_init (unsigned long size, int nid, unsigned long zone,
524 			     unsigned long start_pfn);
525 #  endif /* CONFIG_VIRTUAL_MEM_MAP */
526 # endif /* !__ASSEMBLY__ */
527 
528 /*
529  * Identity-mapped regions use a large page size.  We'll call such large pages
530  * "granules".  If you can think of a better name that's unambiguous, let me
531  * know...
532  */
533 #if defined(CONFIG_IA64_GRANULE_64MB)
534 # define IA64_GRANULE_SHIFT	_PAGE_SIZE_64M
535 #elif defined(CONFIG_IA64_GRANULE_16MB)
536 # define IA64_GRANULE_SHIFT	_PAGE_SIZE_16M
537 #endif
538 #define IA64_GRANULE_SIZE	(1 << IA64_GRANULE_SHIFT)
539 /*
540  * log2() of the page size we use to map the kernel image (IA64_TR_KERNEL):
541  */
542 #define KERNEL_TR_PAGE_SHIFT	_PAGE_SIZE_64M
543 #define KERNEL_TR_PAGE_SIZE	(1 << KERNEL_TR_PAGE_SHIFT)
544 
545 /* These tell get_user_pages() that the first gate page is accessible from user-level.  */
546 #define FIXADDR_USER_START	GATE_ADDR
547 #ifdef HAVE_BUGGY_SEGREL
548 # define FIXADDR_USER_END	(GATE_ADDR + 2*PAGE_SIZE)
549 #else
550 # define FIXADDR_USER_END	(GATE_ADDR + 2*PERCPU_PAGE_SIZE)
551 #endif
552 
553 #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
554 #define __HAVE_ARCH_PTEP_GET_AND_CLEAR
555 #define __HAVE_ARCH_PTEP_SET_WRPROTECT
556 #define __HAVE_ARCH_PTE_SAME
557 #define __HAVE_ARCH_PGD_OFFSET_GATE
558 
559 
560 #if CONFIG_PGTABLE_LEVELS == 3
561 #include <asm-generic/pgtable-nopud.h>
562 #endif
563 #include <asm-generic/pgtable-nop4d.h>
564 
565 #endif /* _ASM_IA64_PGTABLE_H */
566