xref: /openbmc/linux/arch/ia64/include/asm/pgtable.h (revision b627b4ed)
1 #ifndef _ASM_IA64_PGTABLE_H
2 #define _ASM_IA64_PGTABLE_H
3 
4 /*
5  * This file contains the functions and defines necessary to modify and use
6  * the IA-64 page table tree.
7  *
8  * This hopefully works with any (fixed) IA-64 page-size, as defined
9  * in <asm/page.h>.
10  *
11  * Copyright (C) 1998-2005 Hewlett-Packard Co
12  *	David Mosberger-Tang <davidm@hpl.hp.com>
13  */
14 
15 
16 #include <asm/mman.h>
17 #include <asm/page.h>
18 #include <asm/processor.h>
19 #include <asm/system.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 /* Valid only for a PTE with the present bit cleared: */
62 #define _PAGE_FILE		(1 << 1)		/* see swap & file pte remarks below */
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 #ifdef CONFIG_PGTABLE_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 #ifdef CONFIG_PGTABLE_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 #define FIRST_USER_ADDRESS	0
135 
136 /*
137  * All the normal masks have the "page accessed" bits on, as any time
138  * they are used, the page is accessed. They are cleared only by the
139  * page-out routines.
140  */
141 #define PAGE_NONE	__pgprot(_PAGE_PROTNONE | _PAGE_A)
142 #define PAGE_SHARED	__pgprot(__ACCESS_BITS | _PAGE_PL_3 | _PAGE_AR_RW)
143 #define PAGE_READONLY	__pgprot(__ACCESS_BITS | _PAGE_PL_3 | _PAGE_AR_R)
144 #define PAGE_COPY	__pgprot(__ACCESS_BITS | _PAGE_PL_3 | _PAGE_AR_R)
145 #define PAGE_COPY_EXEC	__pgprot(__ACCESS_BITS | _PAGE_PL_3 | _PAGE_AR_RX)
146 #define PAGE_GATE	__pgprot(__ACCESS_BITS | _PAGE_PL_0 | _PAGE_AR_X_RX)
147 #define PAGE_KERNEL	__pgprot(__DIRTY_BITS  | _PAGE_PL_0 | _PAGE_AR_RWX)
148 #define PAGE_KERNELRX	__pgprot(__ACCESS_BITS | _PAGE_PL_0 | _PAGE_AR_RX)
149 
150 # ifndef __ASSEMBLY__
151 
152 #include <linux/sched.h>	/* for mm_struct */
153 #include <linux/bitops.h>
154 #include <asm/cacheflush.h>
155 #include <asm/mmu_context.h>
156 #include <asm/processor.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 __P000	PAGE_NONE
168 #define __P001	PAGE_READONLY
169 #define __P010	PAGE_READONLY	/* write to priv pg -> copy & make writable */
170 #define __P011	PAGE_READONLY	/* ditto */
171 #define __P100	__pgprot(__ACCESS_BITS | _PAGE_PL_3 | _PAGE_AR_X_RX)
172 #define __P101	__pgprot(__ACCESS_BITS | _PAGE_PL_3 | _PAGE_AR_RX)
173 #define __P110	PAGE_COPY_EXEC
174 #define __P111	PAGE_COPY_EXEC
175 
176 #define __S000	PAGE_NONE
177 #define __S001	PAGE_READONLY
178 #define __S010	PAGE_SHARED	/* we don't have (and don't need) write-only */
179 #define __S011	PAGE_SHARED
180 #define __S100	__pgprot(__ACCESS_BITS | _PAGE_PL_3 | _PAGE_AR_X_RX)
181 #define __S101	__pgprot(__ACCESS_BITS | _PAGE_PL_3 | _PAGE_AR_RX)
182 #define __S110	__pgprot(__ACCESS_BITS | _PAGE_PL_3 | _PAGE_AR_RWX)
183 #define __S111	__pgprot(__ACCESS_BITS | _PAGE_PL_3 | _PAGE_AR_RWX)
184 
185 #define pgd_ERROR(e)	printk("%s:%d: bad pgd %016lx.\n", __FILE__, __LINE__, pgd_val(e))
186 #ifdef CONFIG_PGTABLE_4
187 #define pud_ERROR(e)	printk("%s:%d: bad pud %016lx.\n", __FILE__, __LINE__, pud_val(e))
188 #endif
189 #define pmd_ERROR(e)	printk("%s:%d: bad pmd %016lx.\n", __FILE__, __LINE__, pmd_val(e))
190 #define pte_ERROR(e)	printk("%s:%d: bad pte %016lx.\n", __FILE__, __LINE__, pte_val(e))
191 
192 
193 /*
194  * Some definitions to translate between mem_map, PTEs, and page addresses:
195  */
196 
197 
198 /* Quick test to see if ADDR is a (potentially) valid physical address. */
199 static inline long
200 ia64_phys_addr_valid (unsigned long addr)
201 {
202 	return (addr & (local_cpu_data->unimpl_pa_mask)) == 0;
203 }
204 
205 /*
206  * kern_addr_valid(ADDR) tests if ADDR is pointing to valid kernel
207  * memory.  For the return value to be meaningful, ADDR must be >=
208  * PAGE_OFFSET.  This operation can be relatively expensive (e.g.,
209  * require a hash-, or multi-level tree-lookup or something of that
210  * sort) but it guarantees to return TRUE only if accessing the page
211  * at that address does not cause an error.  Note that there may be
212  * addresses for which kern_addr_valid() returns FALSE even though an
213  * access would not cause an error (e.g., this is typically true for
214  * memory mapped I/O regions.
215  *
216  * XXX Need to implement this for IA-64.
217  */
218 #define kern_addr_valid(addr)	(1)
219 
220 
221 /*
222  * Now come the defines and routines to manage and access the three-level
223  * page table.
224  */
225 
226 
227 #define VMALLOC_START		(RGN_BASE(RGN_GATE) + 0x200000000UL)
228 #ifdef CONFIG_VIRTUAL_MEM_MAP
229 # define VMALLOC_END_INIT	(RGN_BASE(RGN_GATE) + (1UL << (4*PAGE_SHIFT - 9)))
230 # define VMALLOC_END		vmalloc_end
231   extern unsigned long vmalloc_end;
232 #else
233 #if defined(CONFIG_SPARSEMEM) && defined(CONFIG_SPARSEMEM_VMEMMAP)
234 /* SPARSEMEM_VMEMMAP uses half of vmalloc... */
235 # define VMALLOC_END		(RGN_BASE(RGN_GATE) + (1UL << (4*PAGE_SHIFT - 10)))
236 # define vmemmap		((struct page *)VMALLOC_END)
237 #else
238 # define VMALLOC_END		(RGN_BASE(RGN_GATE) + (1UL << (4*PAGE_SHIFT - 9)))
239 #endif
240 #endif
241 
242 /* fs/proc/kcore.c */
243 #define	kc_vaddr_to_offset(v) ((v) - RGN_BASE(RGN_GATE))
244 #define	kc_offset_to_vaddr(o) ((o) + RGN_BASE(RGN_GATE))
245 
246 #define RGN_MAP_SHIFT (PGDIR_SHIFT + PTRS_PER_PGD_SHIFT - 3)
247 #define RGN_MAP_LIMIT	((1UL << RGN_MAP_SHIFT) - PAGE_SIZE)	/* per region addr limit */
248 
249 /*
250  * Conversion functions: convert page frame number (pfn) and a protection value to a page
251  * table entry (pte).
252  */
253 #define pfn_pte(pfn, pgprot) \
254 ({ pte_t __pte; pte_val(__pte) = ((pfn) << PAGE_SHIFT) | pgprot_val(pgprot); __pte; })
255 
256 /* Extract pfn from pte.  */
257 #define pte_pfn(_pte)		((pte_val(_pte) & _PFN_MASK) >> PAGE_SHIFT)
258 
259 #define mk_pte(page, pgprot)	pfn_pte(page_to_pfn(page), (pgprot))
260 
261 /* This takes a physical page address that is used by the remapping functions */
262 #define mk_pte_phys(physpage, pgprot) \
263 ({ pte_t __pte; pte_val(__pte) = physpage + pgprot_val(pgprot); __pte; })
264 
265 #define pte_modify(_pte, newprot) \
266 	(__pte((pte_val(_pte) & ~_PAGE_CHG_MASK) | (pgprot_val(newprot) & _PAGE_CHG_MASK)))
267 
268 #define pte_none(pte) 			(!pte_val(pte))
269 #define pte_present(pte)		(pte_val(pte) & (_PAGE_P | _PAGE_PROTNONE))
270 #define pte_clear(mm,addr,pte)		(pte_val(*(pte)) = 0UL)
271 /* pte_page() returns the "struct page *" corresponding to the PTE: */
272 #define pte_page(pte)			virt_to_page(((pte_val(pte) & _PFN_MASK) + PAGE_OFFSET))
273 
274 #define pmd_none(pmd)			(!pmd_val(pmd))
275 #define pmd_bad(pmd)			(!ia64_phys_addr_valid(pmd_val(pmd)))
276 #define pmd_present(pmd)		(pmd_val(pmd) != 0UL)
277 #define pmd_clear(pmdp)			(pmd_val(*(pmdp)) = 0UL)
278 #define pmd_page_vaddr(pmd)		((unsigned long) __va(pmd_val(pmd) & _PFN_MASK))
279 #define pmd_page(pmd)			virt_to_page((pmd_val(pmd) + PAGE_OFFSET))
280 
281 #define pud_none(pud)			(!pud_val(pud))
282 #define pud_bad(pud)			(!ia64_phys_addr_valid(pud_val(pud)))
283 #define pud_present(pud)		(pud_val(pud) != 0UL)
284 #define pud_clear(pudp)			(pud_val(*(pudp)) = 0UL)
285 #define pud_page_vaddr(pud)		((unsigned long) __va(pud_val(pud) & _PFN_MASK))
286 #define pud_page(pud)			virt_to_page((pud_val(pud) + PAGE_OFFSET))
287 
288 #ifdef CONFIG_PGTABLE_4
289 #define pgd_none(pgd)			(!pgd_val(pgd))
290 #define pgd_bad(pgd)			(!ia64_phys_addr_valid(pgd_val(pgd)))
291 #define pgd_present(pgd)		(pgd_val(pgd) != 0UL)
292 #define pgd_clear(pgdp)			(pgd_val(*(pgdp)) = 0UL)
293 #define pgd_page_vaddr(pgd)		((unsigned long) __va(pgd_val(pgd) & _PFN_MASK))
294 #define pgd_page(pgd)			virt_to_page((pgd_val(pgd) + PAGE_OFFSET))
295 #endif
296 
297 /*
298  * The following have defined behavior only work if pte_present() is true.
299  */
300 #define pte_write(pte)	((unsigned) (((pte_val(pte) & _PAGE_AR_MASK) >> _PAGE_AR_SHIFT) - 2) <= 4)
301 #define pte_exec(pte)		((pte_val(pte) & _PAGE_AR_RX) != 0)
302 #define pte_dirty(pte)		((pte_val(pte) & _PAGE_D) != 0)
303 #define pte_young(pte)		((pte_val(pte) & _PAGE_A) != 0)
304 #define pte_file(pte)		((pte_val(pte) & _PAGE_FILE) != 0)
305 #define pte_special(pte)	0
306 
307 /*
308  * Note: we convert AR_RWX to AR_RX and AR_RW to AR_R by clearing the 2nd bit in the
309  * access rights:
310  */
311 #define pte_wrprotect(pte)	(__pte(pte_val(pte) & ~_PAGE_AR_RW))
312 #define pte_mkwrite(pte)	(__pte(pte_val(pte) | _PAGE_AR_RW))
313 #define pte_mkold(pte)		(__pte(pte_val(pte) & ~_PAGE_A))
314 #define pte_mkyoung(pte)	(__pte(pte_val(pte) | _PAGE_A))
315 #define pte_mkclean(pte)	(__pte(pte_val(pte) & ~_PAGE_D))
316 #define pte_mkdirty(pte)	(__pte(pte_val(pte) | _PAGE_D))
317 #define pte_mkhuge(pte)		(__pte(pte_val(pte)))
318 #define pte_mkspecial(pte)	(pte)
319 
320 /*
321  * Because ia64's Icache and Dcache is not coherent (on a cpu), we need to
322  * sync icache and dcache when we insert *new* executable page.
323  *  __ia64_sync_icache_dcache() check Pg_arch_1 bit and flush icache
324  * if necessary.
325  *
326  *  set_pte() is also called by the kernel, but we can expect that the kernel
327  *  flushes icache explicitly if necessary.
328  */
329 #define pte_present_exec_user(pte)\
330 	((pte_val(pte) & (_PAGE_P | _PAGE_PL_MASK | _PAGE_AR_RX)) == \
331 		(_PAGE_P | _PAGE_PL_3 | _PAGE_AR_RX))
332 
333 extern void __ia64_sync_icache_dcache(pte_t pteval);
334 static inline void set_pte(pte_t *ptep, pte_t pteval)
335 {
336 	/* page is present && page is user  && page is executable
337 	 * && (page swapin or new page or page migraton
338 	 *	|| copy_on_write with page copying.)
339 	 */
340 	if (pte_present_exec_user(pteval) &&
341 	    (!pte_present(*ptep) ||
342 		pte_pfn(*ptep) != pte_pfn(pteval)))
343 		/* load_module() calles flush_icache_range() explicitly*/
344 		__ia64_sync_icache_dcache(pteval);
345 	*ptep = pteval;
346 }
347 
348 #define set_pte_at(mm,addr,ptep,pteval) set_pte(ptep,pteval)
349 
350 /*
351  * Make page protection values cacheable, uncacheable, or write-
352  * combining.  Note that "protection" is really a misnomer here as the
353  * protection value contains the memory attribute bits, dirty bits, and
354  * various other bits as well.
355  */
356 #define pgprot_cacheable(prot)		__pgprot((pgprot_val(prot) & ~_PAGE_MA_MASK) | _PAGE_MA_WB)
357 #define pgprot_noncached(prot)		__pgprot((pgprot_val(prot) & ~_PAGE_MA_MASK) | _PAGE_MA_UC)
358 #define pgprot_writecombine(prot)	__pgprot((pgprot_val(prot) & ~_PAGE_MA_MASK) | _PAGE_MA_WC)
359 
360 struct file;
361 extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
362 				     unsigned long size, pgprot_t vma_prot);
363 #define __HAVE_PHYS_MEM_ACCESS_PROT
364 
365 static inline unsigned long
366 pgd_index (unsigned long address)
367 {
368 	unsigned long region = address >> 61;
369 	unsigned long l1index = (address >> PGDIR_SHIFT) & ((PTRS_PER_PGD >> 3) - 1);
370 
371 	return (region << (PAGE_SHIFT - 6)) | l1index;
372 }
373 
374 /* The offset in the 1-level directory is given by the 3 region bits
375    (61..63) and the level-1 bits.  */
376 static inline pgd_t*
377 pgd_offset (const struct mm_struct *mm, unsigned long address)
378 {
379 	return mm->pgd + pgd_index(address);
380 }
381 
382 /* In the kernel's mapped region we completely ignore the region number
383    (since we know it's in region number 5). */
384 #define pgd_offset_k(addr) \
385 	(init_mm.pgd + (((addr) >> PGDIR_SHIFT) & (PTRS_PER_PGD - 1)))
386 
387 /* Look up a pgd entry in the gate area.  On IA-64, the gate-area
388    resides in the kernel-mapped segment, hence we use pgd_offset_k()
389    here.  */
390 #define pgd_offset_gate(mm, addr)	pgd_offset_k(addr)
391 
392 #ifdef CONFIG_PGTABLE_4
393 /* Find an entry in the second-level page table.. */
394 #define pud_offset(dir,addr) \
395 	((pud_t *) pgd_page_vaddr(*(dir)) + (((addr) >> PUD_SHIFT) & (PTRS_PER_PUD - 1)))
396 #endif
397 
398 /* Find an entry in the third-level page table.. */
399 #define pmd_offset(dir,addr) \
400 	((pmd_t *) pud_page_vaddr(*(dir)) + (((addr) >> PMD_SHIFT) & (PTRS_PER_PMD - 1)))
401 
402 /*
403  * Find an entry in the third-level page table.  This looks more complicated than it
404  * should be because some platforms place page tables in high memory.
405  */
406 #define pte_index(addr)	 	(((addr) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
407 #define pte_offset_kernel(dir,addr)	((pte_t *) pmd_page_vaddr(*(dir)) + pte_index(addr))
408 #define pte_offset_map(dir,addr)	pte_offset_kernel(dir, addr)
409 #define pte_offset_map_nested(dir,addr)	pte_offset_map(dir, addr)
410 #define pte_unmap(pte)			do { } while (0)
411 #define pte_unmap_nested(pte)		do { } while (0)
412 
413 /* atomic versions of the some PTE manipulations: */
414 
415 static inline int
416 ptep_test_and_clear_young (struct vm_area_struct *vma, unsigned long addr, pte_t *ptep)
417 {
418 #ifdef CONFIG_SMP
419 	if (!pte_young(*ptep))
420 		return 0;
421 	return test_and_clear_bit(_PAGE_A_BIT, ptep);
422 #else
423 	pte_t pte = *ptep;
424 	if (!pte_young(pte))
425 		return 0;
426 	set_pte_at(vma->vm_mm, addr, ptep, pte_mkold(pte));
427 	return 1;
428 #endif
429 }
430 
431 static inline pte_t
432 ptep_get_and_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
433 {
434 #ifdef CONFIG_SMP
435 	return __pte(xchg((long *) ptep, 0));
436 #else
437 	pte_t pte = *ptep;
438 	pte_clear(mm, addr, ptep);
439 	return pte;
440 #endif
441 }
442 
443 static inline void
444 ptep_set_wrprotect(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
445 {
446 #ifdef CONFIG_SMP
447 	unsigned long new, old;
448 
449 	do {
450 		old = pte_val(*ptep);
451 		new = pte_val(pte_wrprotect(__pte (old)));
452 	} while (cmpxchg((unsigned long *) ptep, old, new) != old);
453 #else
454 	pte_t old_pte = *ptep;
455 	set_pte_at(mm, addr, ptep, pte_wrprotect(old_pte));
456 #endif
457 }
458 
459 static inline int
460 pte_same (pte_t a, pte_t b)
461 {
462 	return pte_val(a) == pte_val(b);
463 }
464 
465 #define update_mmu_cache(vma, address, pte) do { } while (0)
466 
467 extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
468 extern void paging_init (void);
469 
470 /*
471  * Note: The macros below rely on the fact that MAX_SWAPFILES_SHIFT <= number of
472  *	 bits in the swap-type field of the swap pte.  It would be nice to
473  *	 enforce that, but we can't easily include <linux/swap.h> here.
474  *	 (Of course, better still would be to define MAX_SWAPFILES_SHIFT here...).
475  *
476  * Format of swap pte:
477  *	bit   0   : present bit (must be zero)
478  *	bit   1   : _PAGE_FILE (must be zero)
479  *	bits  2- 8: swap-type
480  *	bits  9-62: swap offset
481  *	bit  63   : _PAGE_PROTNONE bit
482  *
483  * Format of file pte:
484  *	bit   0   : present bit (must be zero)
485  *	bit   1   : _PAGE_FILE (must be one)
486  *	bits  2-62: file_offset/PAGE_SIZE
487  *	bit  63   : _PAGE_PROTNONE bit
488  */
489 #define __swp_type(entry)		(((entry).val >> 2) & 0x7f)
490 #define __swp_offset(entry)		(((entry).val << 1) >> 10)
491 #define __swp_entry(type,offset)	((swp_entry_t) { ((type) << 2) | ((long) (offset) << 9) })
492 #define __pte_to_swp_entry(pte)		((swp_entry_t) { pte_val(pte) })
493 #define __swp_entry_to_pte(x)		((pte_t) { (x).val })
494 
495 #define PTE_FILE_MAX_BITS		61
496 #define pte_to_pgoff(pte)		((pte_val(pte) << 1) >> 3)
497 #define pgoff_to_pte(off)		((pte_t) { ((off) << 2) | _PAGE_FILE })
498 
499 #define io_remap_pfn_range(vma, vaddr, pfn, size, prot)		\
500 		remap_pfn_range(vma, vaddr, pfn, size, prot)
501 
502 /*
503  * ZERO_PAGE is a global shared page that is always zero: used
504  * for zero-mapped memory areas etc..
505  */
506 extern unsigned long empty_zero_page[PAGE_SIZE/sizeof(unsigned long)];
507 extern struct page *zero_page_memmap_ptr;
508 #define ZERO_PAGE(vaddr) (zero_page_memmap_ptr)
509 
510 /* We provide our own get_unmapped_area to cope with VA holes for userland */
511 #define HAVE_ARCH_UNMAPPED_AREA
512 
513 #ifdef CONFIG_HUGETLB_PAGE
514 #define HUGETLB_PGDIR_SHIFT	(HPAGE_SHIFT + 2*(PAGE_SHIFT-3))
515 #define HUGETLB_PGDIR_SIZE	(__IA64_UL(1) << HUGETLB_PGDIR_SHIFT)
516 #define HUGETLB_PGDIR_MASK	(~(HUGETLB_PGDIR_SIZE-1))
517 #endif
518 
519 
520 #define __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
521 /*
522  * Update PTEP with ENTRY, which is guaranteed to be a less
523  * restrictive PTE.  That is, ENTRY may have the ACCESSED, DIRTY, and
524  * WRITABLE bits turned on, when the value at PTEP did not.  The
525  * WRITABLE bit may only be turned if SAFELY_WRITABLE is TRUE.
526  *
527  * SAFELY_WRITABLE is TRUE if we can update the value at PTEP without
528  * having to worry about races.  On SMP machines, there are only two
529  * cases where this is true:
530  *
531  *	(1) *PTEP has the PRESENT bit turned OFF
532  *	(2) ENTRY has the DIRTY bit turned ON
533  *
534  * On ia64, we could implement this routine with a cmpxchg()-loop
535  * which ORs in the _PAGE_A/_PAGE_D bit if they're set in ENTRY.
536  * However, like on x86, we can get a more streamlined version by
537  * observing that it is OK to drop ACCESSED bit updates when
538  * SAFELY_WRITABLE is FALSE.  Besides being rare, all that would do is
539  * result in an extra Access-bit fault, which would then turn on the
540  * ACCESSED bit in the low-level fault handler (iaccess_bit or
541  * daccess_bit in ivt.S).
542  */
543 #ifdef CONFIG_SMP
544 # define ptep_set_access_flags(__vma, __addr, __ptep, __entry, __safely_writable) \
545 ({									\
546 	int __changed = !pte_same(*(__ptep), __entry);			\
547 	if (__changed && __safely_writable) {				\
548 		set_pte(__ptep, __entry);				\
549 		flush_tlb_page(__vma, __addr);				\
550 	}								\
551 	__changed;							\
552 })
553 #else
554 # define ptep_set_access_flags(__vma, __addr, __ptep, __entry, __safely_writable) \
555 ({									\
556 	int __changed = !pte_same(*(__ptep), __entry);			\
557 	if (__changed) {						\
558 		set_pte_at((__vma)->vm_mm, (__addr), __ptep, __entry);	\
559 		flush_tlb_page(__vma, __addr);				\
560 	}								\
561 	__changed;							\
562 })
563 #endif
564 
565 #  ifdef CONFIG_VIRTUAL_MEM_MAP
566   /* arch mem_map init routine is needed due to holes in a virtual mem_map */
567 #   define __HAVE_ARCH_MEMMAP_INIT
568     extern void memmap_init (unsigned long size, int nid, unsigned long zone,
569 			     unsigned long start_pfn);
570 #  endif /* CONFIG_VIRTUAL_MEM_MAP */
571 # endif /* !__ASSEMBLY__ */
572 
573 /*
574  * Identity-mapped regions use a large page size.  We'll call such large pages
575  * "granules".  If you can think of a better name that's unambiguous, let me
576  * know...
577  */
578 #if defined(CONFIG_IA64_GRANULE_64MB)
579 # define IA64_GRANULE_SHIFT	_PAGE_SIZE_64M
580 #elif defined(CONFIG_IA64_GRANULE_16MB)
581 # define IA64_GRANULE_SHIFT	_PAGE_SIZE_16M
582 #endif
583 #define IA64_GRANULE_SIZE	(1 << IA64_GRANULE_SHIFT)
584 /*
585  * log2() of the page size we use to map the kernel image (IA64_TR_KERNEL):
586  */
587 #define KERNEL_TR_PAGE_SHIFT	_PAGE_SIZE_64M
588 #define KERNEL_TR_PAGE_SIZE	(1 << KERNEL_TR_PAGE_SHIFT)
589 
590 /*
591  * No page table caches to initialise
592  */
593 #define pgtable_cache_init()	do { } while (0)
594 
595 /* These tell get_user_pages() that the first gate page is accessible from user-level.  */
596 #define FIXADDR_USER_START	GATE_ADDR
597 #ifdef HAVE_BUGGY_SEGREL
598 # define FIXADDR_USER_END	(GATE_ADDR + 2*PAGE_SIZE)
599 #else
600 # define FIXADDR_USER_END	(GATE_ADDR + 2*PERCPU_PAGE_SIZE)
601 #endif
602 
603 #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
604 #define __HAVE_ARCH_PTEP_GET_AND_CLEAR
605 #define __HAVE_ARCH_PTEP_SET_WRPROTECT
606 #define __HAVE_ARCH_PTE_SAME
607 #define __HAVE_ARCH_PGD_OFFSET_GATE
608 
609 
610 #ifndef CONFIG_PGTABLE_4
611 #include <asm-generic/pgtable-nopud.h>
612 #endif
613 #include <asm-generic/pgtable.h>
614 
615 #endif /* _ASM_IA64_PGTABLE_H */
616