xref: /openbmc/linux/arch/ia64/include/asm/pgtable.h (revision 78c99ba1)
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 #define PAGE_KERNEL_UC	__pgprot(__DIRTY_BITS  | _PAGE_PL_0 | _PAGE_AR_RWX | \
150 				 _PAGE_MA_UC)
151 
152 # ifndef __ASSEMBLY__
153 
154 #include <linux/sched.h>	/* for mm_struct */
155 #include <linux/bitops.h>
156 #include <asm/cacheflush.h>
157 #include <asm/mmu_context.h>
158 #include <asm/processor.h>
159 
160 /*
161  * Next come the mappings that determine how mmap() protection bits
162  * (PROT_EXEC, PROT_READ, PROT_WRITE, PROT_NONE) get implemented.  The
163  * _P version gets used for a private shared memory segment, the _S
164  * version gets used for a shared memory segment with MAP_SHARED on.
165  * In a private shared memory segment, we do a copy-on-write if a task
166  * attempts to write to the page.
167  */
168 	/* xwr */
169 #define __P000	PAGE_NONE
170 #define __P001	PAGE_READONLY
171 #define __P010	PAGE_READONLY	/* write to priv pg -> copy & make writable */
172 #define __P011	PAGE_READONLY	/* ditto */
173 #define __P100	__pgprot(__ACCESS_BITS | _PAGE_PL_3 | _PAGE_AR_X_RX)
174 #define __P101	__pgprot(__ACCESS_BITS | _PAGE_PL_3 | _PAGE_AR_RX)
175 #define __P110	PAGE_COPY_EXEC
176 #define __P111	PAGE_COPY_EXEC
177 
178 #define __S000	PAGE_NONE
179 #define __S001	PAGE_READONLY
180 #define __S010	PAGE_SHARED	/* we don't have (and don't need) write-only */
181 #define __S011	PAGE_SHARED
182 #define __S100	__pgprot(__ACCESS_BITS | _PAGE_PL_3 | _PAGE_AR_X_RX)
183 #define __S101	__pgprot(__ACCESS_BITS | _PAGE_PL_3 | _PAGE_AR_RX)
184 #define __S110	__pgprot(__ACCESS_BITS | _PAGE_PL_3 | _PAGE_AR_RWX)
185 #define __S111	__pgprot(__ACCESS_BITS | _PAGE_PL_3 | _PAGE_AR_RWX)
186 
187 #define pgd_ERROR(e)	printk("%s:%d: bad pgd %016lx.\n", __FILE__, __LINE__, pgd_val(e))
188 #ifdef CONFIG_PGTABLE_4
189 #define pud_ERROR(e)	printk("%s:%d: bad pud %016lx.\n", __FILE__, __LINE__, pud_val(e))
190 #endif
191 #define pmd_ERROR(e)	printk("%s:%d: bad pmd %016lx.\n", __FILE__, __LINE__, pmd_val(e))
192 #define pte_ERROR(e)	printk("%s:%d: bad pte %016lx.\n", __FILE__, __LINE__, pte_val(e))
193 
194 
195 /*
196  * Some definitions to translate between mem_map, PTEs, and page addresses:
197  */
198 
199 
200 /* Quick test to see if ADDR is a (potentially) valid physical address. */
201 static inline long
202 ia64_phys_addr_valid (unsigned long addr)
203 {
204 	return (addr & (local_cpu_data->unimpl_pa_mask)) == 0;
205 }
206 
207 /*
208  * kern_addr_valid(ADDR) tests if ADDR is pointing to valid kernel
209  * memory.  For the return value to be meaningful, ADDR must be >=
210  * PAGE_OFFSET.  This operation can be relatively expensive (e.g.,
211  * require a hash-, or multi-level tree-lookup or something of that
212  * sort) but it guarantees to return TRUE only if accessing the page
213  * at that address does not cause an error.  Note that there may be
214  * addresses for which kern_addr_valid() returns FALSE even though an
215  * access would not cause an error (e.g., this is typically true for
216  * memory mapped I/O regions.
217  *
218  * XXX Need to implement this for IA-64.
219  */
220 #define kern_addr_valid(addr)	(1)
221 
222 
223 /*
224  * Now come the defines and routines to manage and access the three-level
225  * page table.
226  */
227 
228 
229 #define VMALLOC_START		(RGN_BASE(RGN_GATE) + 0x200000000UL)
230 #ifdef CONFIG_VIRTUAL_MEM_MAP
231 # define VMALLOC_END_INIT	(RGN_BASE(RGN_GATE) + (1UL << (4*PAGE_SHIFT - 9)))
232 # define VMALLOC_END		vmalloc_end
233   extern unsigned long vmalloc_end;
234 #else
235 #if defined(CONFIG_SPARSEMEM) && defined(CONFIG_SPARSEMEM_VMEMMAP)
236 /* SPARSEMEM_VMEMMAP uses half of vmalloc... */
237 # define VMALLOC_END		(RGN_BASE(RGN_GATE) + (1UL << (4*PAGE_SHIFT - 10)))
238 # define vmemmap		((struct page *)VMALLOC_END)
239 #else
240 # define VMALLOC_END		(RGN_BASE(RGN_GATE) + (1UL << (4*PAGE_SHIFT - 9)))
241 #endif
242 #endif
243 
244 /* fs/proc/kcore.c */
245 #define	kc_vaddr_to_offset(v) ((v) - RGN_BASE(RGN_GATE))
246 #define	kc_offset_to_vaddr(o) ((o) + RGN_BASE(RGN_GATE))
247 
248 #define RGN_MAP_SHIFT (PGDIR_SHIFT + PTRS_PER_PGD_SHIFT - 3)
249 #define RGN_MAP_LIMIT	((1UL << RGN_MAP_SHIFT) - PAGE_SIZE)	/* per region addr limit */
250 
251 /*
252  * Conversion functions: convert page frame number (pfn) and a protection value to a page
253  * table entry (pte).
254  */
255 #define pfn_pte(pfn, pgprot) \
256 ({ pte_t __pte; pte_val(__pte) = ((pfn) << PAGE_SHIFT) | pgprot_val(pgprot); __pte; })
257 
258 /* Extract pfn from pte.  */
259 #define pte_pfn(_pte)		((pte_val(_pte) & _PFN_MASK) >> PAGE_SHIFT)
260 
261 #define mk_pte(page, pgprot)	pfn_pte(page_to_pfn(page), (pgprot))
262 
263 /* This takes a physical page address that is used by the remapping functions */
264 #define mk_pte_phys(physpage, pgprot) \
265 ({ pte_t __pte; pte_val(__pte) = physpage + pgprot_val(pgprot); __pte; })
266 
267 #define pte_modify(_pte, newprot) \
268 	(__pte((pte_val(_pte) & ~_PAGE_CHG_MASK) | (pgprot_val(newprot) & _PAGE_CHG_MASK)))
269 
270 #define pte_none(pte) 			(!pte_val(pte))
271 #define pte_present(pte)		(pte_val(pte) & (_PAGE_P | _PAGE_PROTNONE))
272 #define pte_clear(mm,addr,pte)		(pte_val(*(pte)) = 0UL)
273 /* pte_page() returns the "struct page *" corresponding to the PTE: */
274 #define pte_page(pte)			virt_to_page(((pte_val(pte) & _PFN_MASK) + PAGE_OFFSET))
275 
276 #define pmd_none(pmd)			(!pmd_val(pmd))
277 #define pmd_bad(pmd)			(!ia64_phys_addr_valid(pmd_val(pmd)))
278 #define pmd_present(pmd)		(pmd_val(pmd) != 0UL)
279 #define pmd_clear(pmdp)			(pmd_val(*(pmdp)) = 0UL)
280 #define pmd_page_vaddr(pmd)		((unsigned long) __va(pmd_val(pmd) & _PFN_MASK))
281 #define pmd_page(pmd)			virt_to_page((pmd_val(pmd) + PAGE_OFFSET))
282 
283 #define pud_none(pud)			(!pud_val(pud))
284 #define pud_bad(pud)			(!ia64_phys_addr_valid(pud_val(pud)))
285 #define pud_present(pud)		(pud_val(pud) != 0UL)
286 #define pud_clear(pudp)			(pud_val(*(pudp)) = 0UL)
287 #define pud_page_vaddr(pud)		((unsigned long) __va(pud_val(pud) & _PFN_MASK))
288 #define pud_page(pud)			virt_to_page((pud_val(pud) + PAGE_OFFSET))
289 
290 #ifdef CONFIG_PGTABLE_4
291 #define pgd_none(pgd)			(!pgd_val(pgd))
292 #define pgd_bad(pgd)			(!ia64_phys_addr_valid(pgd_val(pgd)))
293 #define pgd_present(pgd)		(pgd_val(pgd) != 0UL)
294 #define pgd_clear(pgdp)			(pgd_val(*(pgdp)) = 0UL)
295 #define pgd_page_vaddr(pgd)		((unsigned long) __va(pgd_val(pgd) & _PFN_MASK))
296 #define pgd_page(pgd)			virt_to_page((pgd_val(pgd) + PAGE_OFFSET))
297 #endif
298 
299 /*
300  * The following have defined behavior only work if pte_present() is true.
301  */
302 #define pte_write(pte)	((unsigned) (((pte_val(pte) & _PAGE_AR_MASK) >> _PAGE_AR_SHIFT) - 2) <= 4)
303 #define pte_exec(pte)		((pte_val(pte) & _PAGE_AR_RX) != 0)
304 #define pte_dirty(pte)		((pte_val(pte) & _PAGE_D) != 0)
305 #define pte_young(pte)		((pte_val(pte) & _PAGE_A) != 0)
306 #define pte_file(pte)		((pte_val(pte) & _PAGE_FILE) != 0)
307 #define pte_special(pte)	0
308 
309 /*
310  * Note: we convert AR_RWX to AR_RX and AR_RW to AR_R by clearing the 2nd bit in the
311  * access rights:
312  */
313 #define pte_wrprotect(pte)	(__pte(pte_val(pte) & ~_PAGE_AR_RW))
314 #define pte_mkwrite(pte)	(__pte(pte_val(pte) | _PAGE_AR_RW))
315 #define pte_mkold(pte)		(__pte(pte_val(pte) & ~_PAGE_A))
316 #define pte_mkyoung(pte)	(__pte(pte_val(pte) | _PAGE_A))
317 #define pte_mkclean(pte)	(__pte(pte_val(pte) & ~_PAGE_D))
318 #define pte_mkdirty(pte)	(__pte(pte_val(pte) | _PAGE_D))
319 #define pte_mkhuge(pte)		(__pte(pte_val(pte)))
320 #define pte_mkspecial(pte)	(pte)
321 
322 /*
323  * Because ia64's Icache and Dcache is not coherent (on a cpu), we need to
324  * sync icache and dcache when we insert *new* executable page.
325  *  __ia64_sync_icache_dcache() check Pg_arch_1 bit and flush icache
326  * if necessary.
327  *
328  *  set_pte() is also called by the kernel, but we can expect that the kernel
329  *  flushes icache explicitly if necessary.
330  */
331 #define pte_present_exec_user(pte)\
332 	((pte_val(pte) & (_PAGE_P | _PAGE_PL_MASK | _PAGE_AR_RX)) == \
333 		(_PAGE_P | _PAGE_PL_3 | _PAGE_AR_RX))
334 
335 extern void __ia64_sync_icache_dcache(pte_t pteval);
336 static inline void set_pte(pte_t *ptep, pte_t pteval)
337 {
338 	/* page is present && page is user  && page is executable
339 	 * && (page swapin or new page or page migraton
340 	 *	|| copy_on_write with page copying.)
341 	 */
342 	if (pte_present_exec_user(pteval) &&
343 	    (!pte_present(*ptep) ||
344 		pte_pfn(*ptep) != pte_pfn(pteval)))
345 		/* load_module() calles flush_icache_range() explicitly*/
346 		__ia64_sync_icache_dcache(pteval);
347 	*ptep = pteval;
348 }
349 
350 #define set_pte_at(mm,addr,ptep,pteval) set_pte(ptep,pteval)
351 
352 /*
353  * Make page protection values cacheable, uncacheable, or write-
354  * combining.  Note that "protection" is really a misnomer here as the
355  * protection value contains the memory attribute bits, dirty bits, and
356  * various other bits as well.
357  */
358 #define pgprot_cacheable(prot)		__pgprot((pgprot_val(prot) & ~_PAGE_MA_MASK) | _PAGE_MA_WB)
359 #define pgprot_noncached(prot)		__pgprot((pgprot_val(prot) & ~_PAGE_MA_MASK) | _PAGE_MA_UC)
360 #define pgprot_writecombine(prot)	__pgprot((pgprot_val(prot) & ~_PAGE_MA_MASK) | _PAGE_MA_WC)
361 
362 struct file;
363 extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
364 				     unsigned long size, pgprot_t vma_prot);
365 #define __HAVE_PHYS_MEM_ACCESS_PROT
366 
367 static inline unsigned long
368 pgd_index (unsigned long address)
369 {
370 	unsigned long region = address >> 61;
371 	unsigned long l1index = (address >> PGDIR_SHIFT) & ((PTRS_PER_PGD >> 3) - 1);
372 
373 	return (region << (PAGE_SHIFT - 6)) | l1index;
374 }
375 
376 /* The offset in the 1-level directory is given by the 3 region bits
377    (61..63) and the level-1 bits.  */
378 static inline pgd_t*
379 pgd_offset (const struct mm_struct *mm, unsigned long address)
380 {
381 	return mm->pgd + pgd_index(address);
382 }
383 
384 /* In the kernel's mapped region we completely ignore the region number
385    (since we know it's in region number 5). */
386 #define pgd_offset_k(addr) \
387 	(init_mm.pgd + (((addr) >> PGDIR_SHIFT) & (PTRS_PER_PGD - 1)))
388 
389 /* Look up a pgd entry in the gate area.  On IA-64, the gate-area
390    resides in the kernel-mapped segment, hence we use pgd_offset_k()
391    here.  */
392 #define pgd_offset_gate(mm, addr)	pgd_offset_k(addr)
393 
394 #ifdef CONFIG_PGTABLE_4
395 /* Find an entry in the second-level page table.. */
396 #define pud_offset(dir,addr) \
397 	((pud_t *) pgd_page_vaddr(*(dir)) + (((addr) >> PUD_SHIFT) & (PTRS_PER_PUD - 1)))
398 #endif
399 
400 /* Find an entry in the third-level page table.. */
401 #define pmd_offset(dir,addr) \
402 	((pmd_t *) pud_page_vaddr(*(dir)) + (((addr) >> PMD_SHIFT) & (PTRS_PER_PMD - 1)))
403 
404 /*
405  * Find an entry in the third-level page table.  This looks more complicated than it
406  * should be because some platforms place page tables in high memory.
407  */
408 #define pte_index(addr)	 	(((addr) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
409 #define pte_offset_kernel(dir,addr)	((pte_t *) pmd_page_vaddr(*(dir)) + pte_index(addr))
410 #define pte_offset_map(dir,addr)	pte_offset_kernel(dir, addr)
411 #define pte_offset_map_nested(dir,addr)	pte_offset_map(dir, addr)
412 #define pte_unmap(pte)			do { } while (0)
413 #define pte_unmap_nested(pte)		do { } while (0)
414 
415 /* atomic versions of the some PTE manipulations: */
416 
417 static inline int
418 ptep_test_and_clear_young (struct vm_area_struct *vma, unsigned long addr, pte_t *ptep)
419 {
420 #ifdef CONFIG_SMP
421 	if (!pte_young(*ptep))
422 		return 0;
423 	return test_and_clear_bit(_PAGE_A_BIT, ptep);
424 #else
425 	pte_t pte = *ptep;
426 	if (!pte_young(pte))
427 		return 0;
428 	set_pte_at(vma->vm_mm, addr, ptep, pte_mkold(pte));
429 	return 1;
430 #endif
431 }
432 
433 static inline pte_t
434 ptep_get_and_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
435 {
436 #ifdef CONFIG_SMP
437 	return __pte(xchg((long *) ptep, 0));
438 #else
439 	pte_t pte = *ptep;
440 	pte_clear(mm, addr, ptep);
441 	return pte;
442 #endif
443 }
444 
445 static inline void
446 ptep_set_wrprotect(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
447 {
448 #ifdef CONFIG_SMP
449 	unsigned long new, old;
450 
451 	do {
452 		old = pte_val(*ptep);
453 		new = pte_val(pte_wrprotect(__pte (old)));
454 	} while (cmpxchg((unsigned long *) ptep, old, new) != old);
455 #else
456 	pte_t old_pte = *ptep;
457 	set_pte_at(mm, addr, ptep, pte_wrprotect(old_pte));
458 #endif
459 }
460 
461 static inline int
462 pte_same (pte_t a, pte_t b)
463 {
464 	return pte_val(a) == pte_val(b);
465 }
466 
467 #define update_mmu_cache(vma, address, pte) do { } while (0)
468 
469 extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
470 extern void paging_init (void);
471 
472 /*
473  * Note: The macros below rely on the fact that MAX_SWAPFILES_SHIFT <= number of
474  *	 bits in the swap-type field of the swap pte.  It would be nice to
475  *	 enforce that, but we can't easily include <linux/swap.h> here.
476  *	 (Of course, better still would be to define MAX_SWAPFILES_SHIFT here...).
477  *
478  * Format of swap pte:
479  *	bit   0   : present bit (must be zero)
480  *	bit   1   : _PAGE_FILE (must be zero)
481  *	bits  2- 8: swap-type
482  *	bits  9-62: swap offset
483  *	bit  63   : _PAGE_PROTNONE bit
484  *
485  * Format of file pte:
486  *	bit   0   : present bit (must be zero)
487  *	bit   1   : _PAGE_FILE (must be one)
488  *	bits  2-62: file_offset/PAGE_SIZE
489  *	bit  63   : _PAGE_PROTNONE bit
490  */
491 #define __swp_type(entry)		(((entry).val >> 2) & 0x7f)
492 #define __swp_offset(entry)		(((entry).val << 1) >> 10)
493 #define __swp_entry(type,offset)	((swp_entry_t) { ((type) << 2) | ((long) (offset) << 9) })
494 #define __pte_to_swp_entry(pte)		((swp_entry_t) { pte_val(pte) })
495 #define __swp_entry_to_pte(x)		((pte_t) { (x).val })
496 
497 #define PTE_FILE_MAX_BITS		61
498 #define pte_to_pgoff(pte)		((pte_val(pte) << 1) >> 3)
499 #define pgoff_to_pte(off)		((pte_t) { ((off) << 2) | _PAGE_FILE })
500 
501 #define io_remap_pfn_range(vma, vaddr, pfn, size, prot)		\
502 		remap_pfn_range(vma, vaddr, pfn, size, prot)
503 
504 /*
505  * ZERO_PAGE is a global shared page that is always zero: used
506  * for zero-mapped memory areas etc..
507  */
508 extern unsigned long empty_zero_page[PAGE_SIZE/sizeof(unsigned long)];
509 extern struct page *zero_page_memmap_ptr;
510 #define ZERO_PAGE(vaddr) (zero_page_memmap_ptr)
511 
512 /* We provide our own get_unmapped_area to cope with VA holes for userland */
513 #define HAVE_ARCH_UNMAPPED_AREA
514 
515 #ifdef CONFIG_HUGETLB_PAGE
516 #define HUGETLB_PGDIR_SHIFT	(HPAGE_SHIFT + 2*(PAGE_SHIFT-3))
517 #define HUGETLB_PGDIR_SIZE	(__IA64_UL(1) << HUGETLB_PGDIR_SHIFT)
518 #define HUGETLB_PGDIR_MASK	(~(HUGETLB_PGDIR_SIZE-1))
519 #endif
520 
521 
522 #define __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
523 /*
524  * Update PTEP with ENTRY, which is guaranteed to be a less
525  * restrictive PTE.  That is, ENTRY may have the ACCESSED, DIRTY, and
526  * WRITABLE bits turned on, when the value at PTEP did not.  The
527  * WRITABLE bit may only be turned if SAFELY_WRITABLE is TRUE.
528  *
529  * SAFELY_WRITABLE is TRUE if we can update the value at PTEP without
530  * having to worry about races.  On SMP machines, there are only two
531  * cases where this is true:
532  *
533  *	(1) *PTEP has the PRESENT bit turned OFF
534  *	(2) ENTRY has the DIRTY bit turned ON
535  *
536  * On ia64, we could implement this routine with a cmpxchg()-loop
537  * which ORs in the _PAGE_A/_PAGE_D bit if they're set in ENTRY.
538  * However, like on x86, we can get a more streamlined version by
539  * observing that it is OK to drop ACCESSED bit updates when
540  * SAFELY_WRITABLE is FALSE.  Besides being rare, all that would do is
541  * result in an extra Access-bit fault, which would then turn on the
542  * ACCESSED bit in the low-level fault handler (iaccess_bit or
543  * daccess_bit in ivt.S).
544  */
545 #ifdef CONFIG_SMP
546 # define ptep_set_access_flags(__vma, __addr, __ptep, __entry, __safely_writable) \
547 ({									\
548 	int __changed = !pte_same(*(__ptep), __entry);			\
549 	if (__changed && __safely_writable) {				\
550 		set_pte(__ptep, __entry);				\
551 		flush_tlb_page(__vma, __addr);				\
552 	}								\
553 	__changed;							\
554 })
555 #else
556 # define ptep_set_access_flags(__vma, __addr, __ptep, __entry, __safely_writable) \
557 ({									\
558 	int __changed = !pte_same(*(__ptep), __entry);			\
559 	if (__changed) {						\
560 		set_pte_at((__vma)->vm_mm, (__addr), __ptep, __entry);	\
561 		flush_tlb_page(__vma, __addr);				\
562 	}								\
563 	__changed;							\
564 })
565 #endif
566 
567 #  ifdef CONFIG_VIRTUAL_MEM_MAP
568   /* arch mem_map init routine is needed due to holes in a virtual mem_map */
569 #   define __HAVE_ARCH_MEMMAP_INIT
570     extern void memmap_init (unsigned long size, int nid, unsigned long zone,
571 			     unsigned long start_pfn);
572 #  endif /* CONFIG_VIRTUAL_MEM_MAP */
573 # endif /* !__ASSEMBLY__ */
574 
575 /*
576  * Identity-mapped regions use a large page size.  We'll call such large pages
577  * "granules".  If you can think of a better name that's unambiguous, let me
578  * know...
579  */
580 #if defined(CONFIG_IA64_GRANULE_64MB)
581 # define IA64_GRANULE_SHIFT	_PAGE_SIZE_64M
582 #elif defined(CONFIG_IA64_GRANULE_16MB)
583 # define IA64_GRANULE_SHIFT	_PAGE_SIZE_16M
584 #endif
585 #define IA64_GRANULE_SIZE	(1 << IA64_GRANULE_SHIFT)
586 /*
587  * log2() of the page size we use to map the kernel image (IA64_TR_KERNEL):
588  */
589 #define KERNEL_TR_PAGE_SHIFT	_PAGE_SIZE_64M
590 #define KERNEL_TR_PAGE_SIZE	(1 << KERNEL_TR_PAGE_SHIFT)
591 
592 /*
593  * No page table caches to initialise
594  */
595 #define pgtable_cache_init()	do { } while (0)
596 
597 /* These tell get_user_pages() that the first gate page is accessible from user-level.  */
598 #define FIXADDR_USER_START	GATE_ADDR
599 #ifdef HAVE_BUGGY_SEGREL
600 # define FIXADDR_USER_END	(GATE_ADDR + 2*PAGE_SIZE)
601 #else
602 # define FIXADDR_USER_END	(GATE_ADDR + 2*PERCPU_PAGE_SIZE)
603 #endif
604 
605 #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
606 #define __HAVE_ARCH_PTEP_GET_AND_CLEAR
607 #define __HAVE_ARCH_PTEP_SET_WRPROTECT
608 #define __HAVE_ARCH_PTE_SAME
609 #define __HAVE_ARCH_PGD_OFFSET_GATE
610 
611 
612 #ifndef CONFIG_PGTABLE_4
613 #include <asm-generic/pgtable-nopud.h>
614 #endif
615 #include <asm-generic/pgtable.h>
616 
617 #endif /* _ASM_IA64_PGTABLE_H */
618