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
132 /*
133 * All the normal masks have the "page accessed" bits on, as any time
134 * they are used, the page is accessed. They are cleared only by the
135 * page-out routines.
136 */
137 #define PAGE_NONE __pgprot(_PAGE_PROTNONE | _PAGE_A)
138 #define PAGE_SHARED __pgprot(__ACCESS_BITS | _PAGE_PL_3 | _PAGE_AR_RW)
139 #define PAGE_READONLY __pgprot(__ACCESS_BITS | _PAGE_PL_3 | _PAGE_AR_R)
140 #define PAGE_COPY __pgprot(__ACCESS_BITS | _PAGE_PL_3 | _PAGE_AR_R)
141 #define PAGE_COPY_EXEC __pgprot(__ACCESS_BITS | _PAGE_PL_3 | _PAGE_AR_RX)
142 #define PAGE_GATE __pgprot(__ACCESS_BITS | _PAGE_PL_0 | _PAGE_AR_X_RX)
143 #define PAGE_KERNEL __pgprot(__DIRTY_BITS | _PAGE_PL_0 | _PAGE_AR_RWX)
144 #define PAGE_KERNELRX __pgprot(__ACCESS_BITS | _PAGE_PL_0 | _PAGE_AR_RX)
145 #define PAGE_KERNEL_UC __pgprot(__DIRTY_BITS | _PAGE_PL_0 | _PAGE_AR_RWX | \
146 _PAGE_MA_UC)
147
148 # ifndef __ASSEMBLY__
149
150 #include <linux/sched/mm.h> /* for mm_struct */
151 #include <linux/bitops.h>
152 #include <asm/cacheflush.h>
153 #include <asm/mmu_context.h>
154
155 /*
156 * Next come the mappings that determine how mmap() protection bits
157 * (PROT_EXEC, PROT_READ, PROT_WRITE, PROT_NONE) get implemented. The
158 * _P version gets used for a private shared memory segment, the _S
159 * version gets used for a shared memory segment with MAP_SHARED on.
160 * In a private shared memory segment, we do a copy-on-write if a task
161 * attempts to write to the page.
162 */
163 /* xwr */
164 #define pgd_ERROR(e) printk("%s:%d: bad pgd %016lx.\n", __FILE__, __LINE__, pgd_val(e))
165 #if CONFIG_PGTABLE_LEVELS == 4
166 #define pud_ERROR(e) printk("%s:%d: bad pud %016lx.\n", __FILE__, __LINE__, pud_val(e))
167 #endif
168 #define pmd_ERROR(e) printk("%s:%d: bad pmd %016lx.\n", __FILE__, __LINE__, pmd_val(e))
169 #define pte_ERROR(e) printk("%s:%d: bad pte %016lx.\n", __FILE__, __LINE__, pte_val(e))
170
171
172 /*
173 * Some definitions to translate between mem_map, PTEs, and page addresses:
174 */
175
176
177 /* Quick test to see if ADDR is a (potentially) valid physical address. */
178 static inline long
ia64_phys_addr_valid(unsigned long addr)179 ia64_phys_addr_valid (unsigned long addr)
180 {
181 return (addr & (local_cpu_data->unimpl_pa_mask)) == 0;
182 }
183
184 /*
185 * kern_addr_valid(ADDR) tests if ADDR is pointing to valid kernel
186 * memory. For the return value to be meaningful, ADDR must be >=
187 * PAGE_OFFSET. This operation can be relatively expensive (e.g.,
188 * require a hash-, or multi-level tree-lookup or something of that
189 * sort) but it guarantees to return TRUE only if accessing the page
190 * at that address does not cause an error. Note that there may be
191 * addresses for which kern_addr_valid() returns FALSE even though an
192 * access would not cause an error (e.g., this is typically true for
193 * memory mapped I/O regions.
194 *
195 * XXX Need to implement this for IA-64.
196 */
197 #define kern_addr_valid(addr) (1)
198
199
200 /*
201 * Now come the defines and routines to manage and access the three-level
202 * page table.
203 */
204
205
206 #define VMALLOC_START (RGN_BASE(RGN_GATE) + 0x200000000UL)
207 #if defined(CONFIG_SPARSEMEM) && defined(CONFIG_SPARSEMEM_VMEMMAP)
208 /* SPARSEMEM_VMEMMAP uses half of vmalloc... */
209 # define VMALLOC_END (RGN_BASE(RGN_GATE) + (1UL << (4*PAGE_SHIFT - 10)))
210 # define vmemmap ((struct page *)VMALLOC_END)
211 #else
212 # define VMALLOC_END (RGN_BASE(RGN_GATE) + (1UL << (4*PAGE_SHIFT - 9)))
213 #endif
214
215 /* fs/proc/kcore.c */
216 #define kc_vaddr_to_offset(v) ((v) - RGN_BASE(RGN_GATE))
217 #define kc_offset_to_vaddr(o) ((o) + RGN_BASE(RGN_GATE))
218
219 #define RGN_MAP_SHIFT (PGDIR_SHIFT + PTRS_PER_PGD_SHIFT - 3)
220 #define RGN_MAP_LIMIT ((1UL << RGN_MAP_SHIFT) - PAGE_SIZE) /* per region addr limit */
221
222 /*
223 * Conversion functions: convert page frame number (pfn) and a protection value to a page
224 * table entry (pte).
225 */
226 #define pfn_pte(pfn, pgprot) \
227 ({ pte_t __pte; pte_val(__pte) = ((pfn) << PAGE_SHIFT) | pgprot_val(pgprot); __pte; })
228
229 /* Extract pfn from pte. */
230 #define pte_pfn(_pte) ((pte_val(_pte) & _PFN_MASK) >> PAGE_SHIFT)
231
232 #define mk_pte(page, pgprot) pfn_pte(page_to_pfn(page), (pgprot))
233
234 /* This takes a physical page address that is used by the remapping functions */
235 #define mk_pte_phys(physpage, pgprot) \
236 ({ pte_t __pte; pte_val(__pte) = physpage + pgprot_val(pgprot); __pte; })
237
238 #define pte_modify(_pte, newprot) \
239 (__pte((pte_val(_pte) & ~_PAGE_CHG_MASK) | (pgprot_val(newprot) & _PAGE_CHG_MASK)))
240
241 #define pte_none(pte) (!pte_val(pte))
242 #define pte_present(pte) (pte_val(pte) & (_PAGE_P | _PAGE_PROTNONE))
243 #define pte_clear(mm,addr,pte) (pte_val(*(pte)) = 0UL)
244 /* pte_page() returns the "struct page *" corresponding to the PTE: */
245 #define pte_page(pte) virt_to_page(((pte_val(pte) & _PFN_MASK) + PAGE_OFFSET))
246
247 #define pmd_none(pmd) (!pmd_val(pmd))
248 #define pmd_bad(pmd) (!ia64_phys_addr_valid(pmd_val(pmd)))
249 #define pmd_present(pmd) (pmd_val(pmd) != 0UL)
250 #define pmd_clear(pmdp) (pmd_val(*(pmdp)) = 0UL)
251 #define pmd_page_vaddr(pmd) ((unsigned long) __va(pmd_val(pmd) & _PFN_MASK))
252 #define pmd_pfn(pmd) ((pmd_val(pmd) & _PFN_MASK) >> PAGE_SHIFT)
253 #define pmd_page(pmd) virt_to_page((pmd_val(pmd) + PAGE_OFFSET))
254
255 #define pud_none(pud) (!pud_val(pud))
256 #define pud_bad(pud) (!ia64_phys_addr_valid(pud_val(pud)))
257 #define pud_present(pud) (pud_val(pud) != 0UL)
258 #define pud_clear(pudp) (pud_val(*(pudp)) = 0UL)
259 #define pud_pgtable(pud) ((pmd_t *) __va(pud_val(pud) & _PFN_MASK))
260 #define pud_page(pud) virt_to_page((pud_val(pud) + PAGE_OFFSET))
261
262 #if CONFIG_PGTABLE_LEVELS == 4
263 #define p4d_none(p4d) (!p4d_val(p4d))
264 #define p4d_bad(p4d) (!ia64_phys_addr_valid(p4d_val(p4d)))
265 #define p4d_present(p4d) (p4d_val(p4d) != 0UL)
266 #define p4d_clear(p4dp) (p4d_val(*(p4dp)) = 0UL)
267 #define p4d_pgtable(p4d) ((pud_t *) __va(p4d_val(p4d) & _PFN_MASK))
268 #define p4d_page(p4d) virt_to_page((p4d_val(p4d) + PAGE_OFFSET))
269 #endif
270
271 /*
272 * The following have defined behavior only work if pte_present() is true.
273 */
274 #define pte_write(pte) ((unsigned) (((pte_val(pte) & _PAGE_AR_MASK) >> _PAGE_AR_SHIFT) - 2) <= 4)
275 #define pte_exec(pte) ((pte_val(pte) & _PAGE_AR_RX) != 0)
276 #define pte_dirty(pte) ((pte_val(pte) & _PAGE_D) != 0)
277 #define pte_young(pte) ((pte_val(pte) & _PAGE_A) != 0)
278
279 /*
280 * Note: we convert AR_RWX to AR_RX and AR_RW to AR_R by clearing the 2nd bit in the
281 * access rights:
282 */
283 #define pte_wrprotect(pte) (__pte(pte_val(pte) & ~_PAGE_AR_RW))
284 #define pte_mkwrite(pte) (__pte(pte_val(pte) | _PAGE_AR_RW))
285 #define pte_mkold(pte) (__pte(pte_val(pte) & ~_PAGE_A))
286 #define pte_mkyoung(pte) (__pte(pte_val(pte) | _PAGE_A))
287 #define pte_mkclean(pte) (__pte(pte_val(pte) & ~_PAGE_D))
288 #define pte_mkdirty(pte) (__pte(pte_val(pte) | _PAGE_D))
289 #define pte_mkhuge(pte) (__pte(pte_val(pte)))
290
291 /*
292 * Because ia64's Icache and Dcache is not coherent (on a cpu), we need to
293 * sync icache and dcache when we insert *new* executable page.
294 * __ia64_sync_icache_dcache() check Pg_arch_1 bit and flush icache
295 * if necessary.
296 *
297 * set_pte() is also called by the kernel, but we can expect that the kernel
298 * flushes icache explicitly if necessary.
299 */
300 #define pte_present_exec_user(pte)\
301 ((pte_val(pte) & (_PAGE_P | _PAGE_PL_MASK | _PAGE_AR_RX)) == \
302 (_PAGE_P | _PAGE_PL_3 | _PAGE_AR_RX))
303
304 extern void __ia64_sync_icache_dcache(pte_t pteval);
set_pte(pte_t * ptep,pte_t pteval)305 static inline void set_pte(pte_t *ptep, pte_t pteval)
306 {
307 /* page is present && page is user && page is executable
308 * && (page swapin or new page or page migration
309 * || copy_on_write with page copying.)
310 */
311 if (pte_present_exec_user(pteval) &&
312 (!pte_present(*ptep) ||
313 pte_pfn(*ptep) != pte_pfn(pteval)))
314 /* load_module() calles flush_icache_range() explicitly*/
315 __ia64_sync_icache_dcache(pteval);
316 *ptep = pteval;
317 }
318
319 #define set_pte_at(mm,addr,ptep,pteval) set_pte(ptep,pteval)
320
321 /*
322 * Make page protection values cacheable, uncacheable, or write-
323 * combining. Note that "protection" is really a misnomer here as the
324 * protection value contains the memory attribute bits, dirty bits, and
325 * various other bits as well.
326 */
327 #define pgprot_cacheable(prot) __pgprot((pgprot_val(prot) & ~_PAGE_MA_MASK) | _PAGE_MA_WB)
328 #define pgprot_noncached(prot) __pgprot((pgprot_val(prot) & ~_PAGE_MA_MASK) | _PAGE_MA_UC)
329 #define pgprot_writecombine(prot) __pgprot((pgprot_val(prot) & ~_PAGE_MA_MASK) | _PAGE_MA_WC)
330
331 struct file;
332 extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
333 unsigned long size, pgprot_t vma_prot);
334 #define __HAVE_PHYS_MEM_ACCESS_PROT
335
336 static inline unsigned long
pgd_index(unsigned long address)337 pgd_index (unsigned long address)
338 {
339 unsigned long region = address >> 61;
340 unsigned long l1index = (address >> PGDIR_SHIFT) & ((PTRS_PER_PGD >> 3) - 1);
341
342 return (region << (PAGE_SHIFT - 6)) | l1index;
343 }
344 #define pgd_index pgd_index
345
346 /*
347 * In the kernel's mapped region we know everything is in region number 5, so
348 * as an optimisation its PGD already points to the area for that region.
349 * However, this also means that we cannot use pgd_index() and we must
350 * never add the region here.
351 */
352 #define pgd_offset_k(addr) \
353 (init_mm.pgd + (((addr) >> PGDIR_SHIFT) & (PTRS_PER_PGD - 1)))
354
355 /* Look up a pgd entry in the gate area. On IA-64, the gate-area
356 resides in the kernel-mapped segment, hence we use pgd_offset_k()
357 here. */
358 #define pgd_offset_gate(mm, addr) pgd_offset_k(addr)
359
360 /* atomic versions of the some PTE manipulations: */
361
362 static inline int
ptep_test_and_clear_young(struct vm_area_struct * vma,unsigned long addr,pte_t * ptep)363 ptep_test_and_clear_young (struct vm_area_struct *vma, unsigned long addr, pte_t *ptep)
364 {
365 #ifdef CONFIG_SMP
366 if (!pte_young(*ptep))
367 return 0;
368 return test_and_clear_bit(_PAGE_A_BIT, ptep);
369 #else
370 pte_t pte = *ptep;
371 if (!pte_young(pte))
372 return 0;
373 set_pte_at(vma->vm_mm, addr, ptep, pte_mkold(pte));
374 return 1;
375 #endif
376 }
377
378 static inline pte_t
ptep_get_and_clear(struct mm_struct * mm,unsigned long addr,pte_t * ptep)379 ptep_get_and_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
380 {
381 #ifdef CONFIG_SMP
382 return __pte(xchg((long *) ptep, 0));
383 #else
384 pte_t pte = *ptep;
385 pte_clear(mm, addr, ptep);
386 return pte;
387 #endif
388 }
389
390 static inline void
ptep_set_wrprotect(struct mm_struct * mm,unsigned long addr,pte_t * ptep)391 ptep_set_wrprotect(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
392 {
393 #ifdef CONFIG_SMP
394 unsigned long new, old;
395
396 do {
397 old = pte_val(*ptep);
398 new = pte_val(pte_wrprotect(__pte (old)));
399 } while (cmpxchg((unsigned long *) ptep, old, new) != old);
400 #else
401 pte_t old_pte = *ptep;
402 set_pte_at(mm, addr, ptep, pte_wrprotect(old_pte));
403 #endif
404 }
405
406 static inline int
pte_same(pte_t a,pte_t b)407 pte_same (pte_t a, pte_t b)
408 {
409 return pte_val(a) == pte_val(b);
410 }
411
412 #define update_mmu_cache(vma, address, ptep) do { } while (0)
413
414 extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
415 extern void paging_init (void);
416
417 /*
418 * Note: The macros below rely on the fact that MAX_SWAPFILES_SHIFT <= number of
419 * bits in the swap-type field of the swap pte. It would be nice to
420 * enforce that, but we can't easily include <linux/swap.h> here.
421 * (Of course, better still would be to define MAX_SWAPFILES_SHIFT here...).
422 *
423 * Format of swap pte:
424 * bit 0 : present bit (must be zero)
425 * bits 1- 7: swap-type
426 * bits 8-62: swap offset
427 * bit 63 : _PAGE_PROTNONE bit
428 */
429 #define __swp_type(entry) (((entry).val >> 1) & 0x7f)
430 #define __swp_offset(entry) (((entry).val << 1) >> 9)
431 #define __swp_entry(type,offset) ((swp_entry_t) { ((type) << 1) | ((long) (offset) << 8) })
432 #define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) })
433 #define __swp_entry_to_pte(x) ((pte_t) { (x).val })
434
435 /*
436 * ZERO_PAGE is a global shared page that is always zero: used
437 * for zero-mapped memory areas etc..
438 */
439 extern unsigned long empty_zero_page[PAGE_SIZE/sizeof(unsigned long)];
440 extern struct page *zero_page_memmap_ptr;
441 #define ZERO_PAGE(vaddr) (zero_page_memmap_ptr)
442
443 /* We provide our own get_unmapped_area to cope with VA holes for userland */
444 #define HAVE_ARCH_UNMAPPED_AREA
445
446 #ifdef CONFIG_HUGETLB_PAGE
447 #define HUGETLB_PGDIR_SHIFT (HPAGE_SHIFT + 2*(PAGE_SHIFT-3))
448 #define HUGETLB_PGDIR_SIZE (__IA64_UL(1) << HUGETLB_PGDIR_SHIFT)
449 #define HUGETLB_PGDIR_MASK (~(HUGETLB_PGDIR_SIZE-1))
450 #endif
451
452
453 #define __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
454 /*
455 * Update PTEP with ENTRY, which is guaranteed to be a less
456 * restrictive PTE. That is, ENTRY may have the ACCESSED, DIRTY, and
457 * WRITABLE bits turned on, when the value at PTEP did not. The
458 * WRITABLE bit may only be turned if SAFELY_WRITABLE is TRUE.
459 *
460 * SAFELY_WRITABLE is TRUE if we can update the value at PTEP without
461 * having to worry about races. On SMP machines, there are only two
462 * cases where this is true:
463 *
464 * (1) *PTEP has the PRESENT bit turned OFF
465 * (2) ENTRY has the DIRTY bit turned ON
466 *
467 * On ia64, we could implement this routine with a cmpxchg()-loop
468 * which ORs in the _PAGE_A/_PAGE_D bit if they're set in ENTRY.
469 * However, like on x86, we can get a more streamlined version by
470 * observing that it is OK to drop ACCESSED bit updates when
471 * SAFELY_WRITABLE is FALSE. Besides being rare, all that would do is
472 * result in an extra Access-bit fault, which would then turn on the
473 * ACCESSED bit in the low-level fault handler (iaccess_bit or
474 * daccess_bit in ivt.S).
475 */
476 #ifdef CONFIG_SMP
477 # define ptep_set_access_flags(__vma, __addr, __ptep, __entry, __safely_writable) \
478 ({ \
479 int __changed = !pte_same(*(__ptep), __entry); \
480 if (__changed && __safely_writable) { \
481 set_pte(__ptep, __entry); \
482 flush_tlb_page(__vma, __addr); \
483 } \
484 __changed; \
485 })
486 #else
487 # define ptep_set_access_flags(__vma, __addr, __ptep, __entry, __safely_writable) \
488 ({ \
489 int __changed = !pte_same(*(__ptep), __entry); \
490 if (__changed) { \
491 set_pte_at((__vma)->vm_mm, (__addr), __ptep, __entry); \
492 flush_tlb_page(__vma, __addr); \
493 } \
494 __changed; \
495 })
496 #endif
497 # endif /* !__ASSEMBLY__ */
498
499 /*
500 * Identity-mapped regions use a large page size. We'll call such large pages
501 * "granules". If you can think of a better name that's unambiguous, let me
502 * know...
503 */
504 #if defined(CONFIG_IA64_GRANULE_64MB)
505 # define IA64_GRANULE_SHIFT _PAGE_SIZE_64M
506 #elif defined(CONFIG_IA64_GRANULE_16MB)
507 # define IA64_GRANULE_SHIFT _PAGE_SIZE_16M
508 #endif
509 #define IA64_GRANULE_SIZE (1 << IA64_GRANULE_SHIFT)
510 /*
511 * log2() of the page size we use to map the kernel image (IA64_TR_KERNEL):
512 */
513 #define KERNEL_TR_PAGE_SHIFT _PAGE_SIZE_64M
514 #define KERNEL_TR_PAGE_SIZE (1 << KERNEL_TR_PAGE_SHIFT)
515
516 /* These tell get_user_pages() that the first gate page is accessible from user-level. */
517 #define FIXADDR_USER_START GATE_ADDR
518 #ifdef HAVE_BUGGY_SEGREL
519 # define FIXADDR_USER_END (GATE_ADDR + 2*PAGE_SIZE)
520 #else
521 # define FIXADDR_USER_END (GATE_ADDR + 2*PERCPU_PAGE_SIZE)
522 #endif
523
524 #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
525 #define __HAVE_ARCH_PTEP_GET_AND_CLEAR
526 #define __HAVE_ARCH_PTEP_SET_WRPROTECT
527 #define __HAVE_ARCH_PTE_SAME
528 #define __HAVE_ARCH_PGD_OFFSET_GATE
529
530
531 #if CONFIG_PGTABLE_LEVELS == 3
532 #include <asm-generic/pgtable-nopud.h>
533 #endif
534 #include <asm-generic/pgtable-nop4d.h>
535
536 #endif /* _ASM_IA64_PGTABLE_H */
537