1 #ifndef _X86_64_PGTABLE_H
2 #define _X86_64_PGTABLE_H
3
4 /*
5 * This file contains the functions and defines necessary to modify and use
6 * the x86-64 page table tree.
7 *
8 * x86-64 has a 4 level table setup. Generic linux MM only supports
9 * three levels. The fourth level is currently a single static page that
10 * is shared by everybody and just contains a pointer to the current
11 * three level page setup on the beginning and some kernel mappings at
12 * the end. For more details see Documentation/x86_64/mm.txt
13 */
14 #ifndef __ASSEMBLY__
15 #include <asm/processor.h>
16 #include <asm/fixmap.h>
17 #include <asm/bitops.h>
18 #include <asm/pda.h>
19 #include <linux/threads.h>
20 #include <linux/config.h>
21
22 extern pgd_t level3_kernel_pgt[512];
23 extern pgd_t level3_physmem_pgt[512];
24 extern pgd_t level3_ident_pgt[512];
25 extern pmd_t level2_kernel_pgt[512];
26 extern pml4_t init_level4_pgt[];
27 extern pgd_t boot_vmalloc_pgt[];
28
29 extern void paging_init(void);
30
31 #define swapper_pg_dir NULL
32
33 /* Caches aren't brain-dead on the intel. */
34 #define flush_cache_all() do { } while (0)
35 #define flush_cache_mm(mm) do { } while (0)
36 #define flush_cache_range(mm, start, end) do { } while (0)
37 #define flush_cache_page(vma, vmaddr) do { } while (0)
38 #define flush_page_to_ram(page) do { } while (0)
39 #define flush_dcache_page(page) do { } while (0)
40 #define flush_icache_range(start, end) do { } while (0)
41 #define flush_icache_page(vma,pg) do { } while (0)
42 #define flush_icache_user_range(vma,pg,adr,len) do { } while (0)
43
44 #define __flush_tlb() \
45 do { \
46 unsigned long tmpreg; \
47 \
48 __asm__ __volatile__( \
49 "movq %%cr3, %0; # flush TLB \n" \
50 "movq %0, %%cr3; \n" \
51 : "=r" (tmpreg) \
52 :: "memory"); \
53 } while (0)
54
55 /*
56 * Global pages have to be flushed a bit differently. Not a real
57 * performance problem because this does not happen often.
58 */
59 #define __flush_tlb_global() \
60 do { \
61 unsigned long tmpreg; \
62 \
63 __asm__ __volatile__( \
64 "movq %1, %%cr4; # turn off PGE \n" \
65 "movq %%cr3, %0; # flush TLB \n" \
66 "movq %0, %%cr3; \n" \
67 "movq %2, %%cr4; # turn PGE back on \n" \
68 : "=&r" (tmpreg) \
69 : "r" (mmu_cr4_features & ~(u64)X86_CR4_PGE), \
70 "r" (mmu_cr4_features) \
71 : "memory"); \
72 } while (0)
73
74 #define __flush_tlb_all() __flush_tlb_global()
75
76 #define __flush_tlb_one(addr) __asm__ __volatile__("invlpg %0": :"m" (*(char *) addr))
77
78 /*
79 * ZERO_PAGE is a global shared page that is always zero: used
80 * for zero-mapped memory areas etc..
81 */
82 extern unsigned long empty_zero_page[PAGE_SIZE/sizeof(unsigned long)];
83 #define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page))
84
85 #endif /* !__ASSEMBLY__ */
86
87 #define PML4_SHIFT 39
88 #define PTRS_PER_PML4 512
89
90 /*
91 * PGDIR_SHIFT determines what a 3rd level page table entry can map
92 */
93 #define PGDIR_SHIFT 30
94 #define PTRS_PER_PGD 512
95
96 /*
97 * PMD_SHIFT determines the size of the area a middle-level
98 * page table can map
99 */
100 #define PMD_SHIFT 21
101 #define PTRS_PER_PMD 512
102
103 /*
104 * entries per page directory level
105 */
106 #define PTRS_PER_PTE 512
107
108 #define pte_ERROR(e) \
109 printk("%s:%d: bad pte %p(%016lx).\n", __FILE__, __LINE__, &(e), pte_val(e))
110 #define pmd_ERROR(e) \
111 printk("%s:%d: bad pmd %p(%016lx).\n", __FILE__, __LINE__, &(e), pmd_val(e))
112 #define pgd_ERROR(e) \
113 printk("%s:%d: bad pgd %p(%016lx).\n", __FILE__, __LINE__, &(e), pgd_val(e))
114
115 #define pml4_none(x) (!pml4_val(x))
116 #define pgd_none(x) (!pgd_val(x))
117
118
pgd_present(pgd_t pgd)119 extern inline int pgd_present(pgd_t pgd) { return !pgd_none(pgd); }
120
set_pte(pte_t * dst,pte_t val)121 static inline void set_pte(pte_t *dst, pte_t val)
122 {
123 pte_val(*dst) = pte_val(val);
124 }
125
set_pmd(pmd_t * dst,pmd_t val)126 static inline void set_pmd(pmd_t *dst, pmd_t val)
127 {
128 pmd_val(*dst) = pmd_val(val);
129 }
130
set_pgd(pgd_t * dst,pgd_t val)131 static inline void set_pgd(pgd_t *dst, pgd_t val)
132 {
133 pgd_val(*dst) = pgd_val(val);
134 }
135
set_pml4(pml4_t * dst,pml4_t val)136 static inline void set_pml4(pml4_t *dst, pml4_t val)
137 {
138 pml4_val(*dst) = pml4_val(val);
139 }
140
__pgd_clear(pgd_t * pgd)141 extern inline void __pgd_clear (pgd_t * pgd)
142 {
143 set_pgd(pgd, __pgd(0));
144 }
145
pgd_clear(pgd_t * pgd)146 extern inline void pgd_clear (pgd_t * pgd)
147 {
148 __pgd_clear(pgd);
149 __flush_tlb();
150 }
151
152 #define pgd_page(pgd) \
153 ((unsigned long) __va(pgd_val(pgd) & PHYSICAL_PAGE_MASK))
154 #define __mk_pgd(address,prot) ((pgd_t) { (address) | pgprot_val(prot) })
155
156 /* Find an entry in the second-level page table.. */
157 #define pmd_offset(dir, address) ((pmd_t *) pgd_page(*(dir)) + \
158 __pmd_offset(address))
159 #define __mk_pmd(address,prot) ((pmd_t) { ((address) | pgprot_val(prot)) & __supported_pte_mask})
160
161 #define ptep_get_and_clear(xp) __pte(xchg(&(xp)->pte, 0))
162 #define pte_same(a, b) ((a).pte == (b).pte)
163 #define __mk_pte(page_nr,pgprot) \
164 __pte(((page_nr) << PAGE_SHIFT) | (pgprot_val(pgprot) & __supported_pte_mask))
165 #define PML4_SIZE (1UL << PML4_SHIFT)
166 #define PML4_MASK (~(PML4_SIZE-1))
167 #define PMD_SIZE (1UL << PMD_SHIFT)
168 #define PMD_MASK (~(PMD_SIZE-1))
169 #define PGDIR_SIZE (1UL << PGDIR_SHIFT)
170 #define PGDIR_MASK (~(PGDIR_SIZE-1))
171
172 #define USER_PTRS_PER_PGD (TASK_SIZE/PGDIR_SIZE)
173 #define FIRST_USER_PGD_NR 0
174
175 #define USER_PGD_PTRS (PAGE_OFFSET >> PGDIR_SHIFT)
176 #define KERNEL_PGD_PTRS (PTRS_PER_PGD-USER_PGD_PTRS)
177
178 #define BOOT_USER_L4_PTRS 1
179 #define BOOT_KERNEL_L4_PTRS 511 /* But we will do it in 4rd level */
180
181
182
183 #ifndef __ASSEMBLY__
184 /* IO mappings are the 509th slot in the PML4. We map them high up to make sure
185 they never appear in the node hash table in DISCONTIG configs. */
186 #define IOMAP_START 0xfffffe8000000000
187
188 /* vmalloc space occupies the 510th slot in the PML4. You can have upto 512GB of
189 vmalloc/ioremap space. */
190
191 #define VMALLOC_START 0xffffff0000000000
192 #define VMALLOC_END 0xffffff7fffffffff
193 #define VMALLOC_VMADDR(x) ((unsigned long)(x))
194
195 #define MODULES_VADDR 0xffffffffa0000000
196 #define MODULES_END 0xffffffffafffffff
197 #define MODULES_LEN (MODULES_END - MODULES_VADDR)
198
199 #define _PAGE_BIT_PRESENT 0
200 #define _PAGE_BIT_RW 1
201 #define _PAGE_BIT_USER 2
202 #define _PAGE_BIT_PWT 3 /* Write Through */
203 #define _PAGE_BIT_PCD 4 /* Cache disable */
204 #define _PAGE_BIT_ACCESSED 5
205 #define _PAGE_BIT_DIRTY 6
206 #define _PAGE_BIT_PSE 7 /* 2MB page */
207 #define _PAGE_BIT_GLOBAL 8 /* Global TLB entry PPro+ */
208 #define _PAGE_BIT_NX 63 /* No execute: only valid after cpuid check */
209
210 #define _PAGE_PRESENT 0x001
211 #define _PAGE_RW 0x002
212 #define _PAGE_USER 0x004
213 #define _PAGE_PWT 0x008
214 #define _PAGE_PCD 0x010
215 #define _PAGE_ACCESSED 0x020
216 #define _PAGE_DIRTY 0x040
217 #define _PAGE_PSE 0x080 /* 2MB page */
218 #define _PAGE_GLOBAL 0x100 /* Global TLB entry */
219 #define _PAGE_PGE _PAGE_GLOBAL
220 #define _PAGE_NX (1UL<<_PAGE_BIT_NX)
221
222 #define _PAGE_PROTNONE 0x080 /* If not present */
223
224 #define _PAGE_TABLE (_PAGE_PRESENT | _PAGE_RW | _PAGE_USER | _PAGE_ACCESSED | _PAGE_DIRTY)
225 #define _KERNPG_TABLE (_PAGE_PRESENT | _PAGE_RW | _PAGE_ACCESSED | _PAGE_DIRTY)
226
227 #define KERNPG_TABLE __pgprot(_KERNPG_TABLE)
228
229 #define _PAGE_CHG_MASK (PTE_MASK | _PAGE_ACCESSED | _PAGE_DIRTY)
230
231 #define PAGE_NONE __pgprot(_PAGE_PROTNONE | _PAGE_ACCESSED)
232 #define PAGE_SHARED __pgprot(_PAGE_PRESENT | _PAGE_RW | _PAGE_USER | _PAGE_ACCESSED)
233 #define PAGE_SHARED_NOEXEC __pgprot(_PAGE_NX | _PAGE_PRESENT | _PAGE_RW | _PAGE_USER | _PAGE_ACCESSED)
234 #define PAGE_COPY_NOEXEC __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_ACCESSED | _PAGE_NX)
235 #define PAGE_COPY PAGE_COPY_NOEXEC
236 #define PAGE_COPY_EXEC \
237 __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_ACCESSED)
238 #define PAGE_READONLY __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_ACCESSED | _PAGE_NX)
239 #define PAGE_READONLY_EXEC \
240 __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_ACCESSED)
241 #define PAGE_EXECONLY PAGE_READONLY_EXEC
242
243 #define PAGE_LARGE (_PAGE_PSE|_PAGE_PRESENT)
244
245 #define __PAGE_KERNEL \
246 (_PAGE_PRESENT | _PAGE_RW | _PAGE_DIRTY | _PAGE_ACCESSED | _PAGE_NX)
247 #define __PAGE_KERNEL_NOCACHE (__PAGE_KERNEL | _PAGE_PCD)
248 #define __PAGE_KERNEL_RO (__PAGE_KERNEL & ~_PAGE_RW)
249 #define __PAGE_KERNEL_VSYSCALL (_PAGE_PRESENT | _PAGE_USER | _PAGE_ACCESSED)
250 #define __PAGE_KERNEL_LARGE (__PAGE_KERNEL | _PAGE_PSE)
251 #define __PAGE_KERNEL_LARGE_NOCACHE (__PAGE_KERNEL_LARGE | _PAGE_PCD)
252 #define __PAGE_KERNEL_EXECUTABLE (__PAGE_KERNEL & ~_PAGE_NX)
253 #define __PAGE_USER_NOCACHE_RO \
254 (_PAGE_PRESENT | _PAGE_USER | _PAGE_DIRTY | _PAGE_ACCESSED)
255
256 extern unsigned long __supported_pte_mask;
257 #define __PTE_SUPP(x) __pgprot((x) & __supported_pte_mask)
258
259 /* _NX is masked away in mk_pmd/pte */
260
261 #define PAGE_KERNEL __PTE_SUPP(__PAGE_KERNEL|_PAGE_GLOBAL)
262 #define PAGE_KERNEL_RO __pgprot(__PAGE_KERNEL_RO|_PAGE_GLOBAL)
263 #define PAGE_KERNEL_NOCACHE __pgprot(__PAGE_KERNEL_NOCACHE|_PAGE_GLOBAL)
264 #define PAGE_KERNEL_VSYSCALL __pgprot(__PAGE_KERNEL_VSYSCALL|_PAGE_GLOBAL)
265 #define PAGE_KERNEL_LARGE __pgprot(__PAGE_KERNEL_LARGE|_PAGE_GLOBAL)
266 #define PAGE_KERNEL_LARGE_NOCACHE __pgprot(__PAGE_KERNEL_LARGE_NOCACHE|_PAGE_GLOBAL)
267 #define PAGE_USER_NOCACHE_RO __pgprot(__PAGE_USER_NOCACHE_RO|_PAGE_GLOBAL)
268 #define PAGE_KERNEL_EXECUTABLE __pgprot(__PAGE_KERNEL_EXECUTABLE|_PAGE_GLOBAL)
269
270 /* xwr */
271 #define __P000 PAGE_NONE
272 #define __P001 PAGE_READONLY
273 #define __P010 PAGE_COPY
274 #define __P011 PAGE_COPY
275 #define __P100 PAGE_EXECONLY
276 #define __P101 PAGE_READONLY_EXEC
277 #define __P110 PAGE_COPY_EXEC
278 #define __P111 PAGE_COPY_EXEC
279
280 /* xwr */
281 #define __S000 PAGE_NONE
282 #define __S001 PAGE_READONLY
283 #define __S010 PAGE_SHARED_NOEXEC
284 #define __S011 PAGE_SHARED_NOEXEC
285 #define __S100 PAGE_EXECONLY
286 #define __S101 PAGE_READONLY_EXEC
287 #define __S110 PAGE_SHARED
288 #define __S111 PAGE_SHARED
289
pgd_bad(pgd_t pgd)290 static inline unsigned long pgd_bad(pgd_t pgd)
291 {
292 unsigned long val = pgd_val(pgd);
293 val &= ~PAGE_MASK;
294 val &= ~(_PAGE_USER | _PAGE_DIRTY);
295 return val & ~(_PAGE_PRESENT | _PAGE_RW | _PAGE_ACCESSED);
296 }
297
298 /*
299 * Handling allocation failures during page table setup.
300 */
301 extern void __handle_bad_pmd(pmd_t * pmd);
302 extern void __handle_bad_pmd_kernel(pmd_t * pmd);
303
304 #define pte_none(x) (!pte_val(x))
305 #define pte_present(x) (pte_val(x) & (_PAGE_PRESENT | _PAGE_PROTNONE))
306 #define pte_clear(xp) do { set_pte(xp, __pte(0)); } while (0)
307
308 #define pmd_none(x) (!pmd_val(x))
309 #define pmd_present(x) (pmd_val(x) & _PAGE_PRESENT)
310 #define pmd_clear(xp) do { set_pmd(xp, __pmd(0)); } while (0)
311 #define pmd_bad(x) \
312 ((pmd_val(x) & (~PAGE_MASK & (~_PAGE_USER))) != _KERNPG_TABLE )
313
314 #define pages_to_mb(x) ((x) >> (20-PAGE_SHIFT))
315
316 #ifndef CONFIG_DISCONTIGMEM
317 #define pte_page(x) (pfn_to_page((pte_val(x) & PHYSICAL_PAGE_MASK) >> PAGE_SHIFT))
318 #endif
319 /*
320 * The following only work if pte_present() is true.
321 * Undefined behaviour if not..
322 */
pte_read(pte_t pte)323 extern inline int pte_read(pte_t pte) { return pte_val(pte) & _PAGE_USER; }
pte_exec(pte_t pte)324 extern inline int pte_exec(pte_t pte) { return pte_val(pte) & _PAGE_USER; }
pte_dirty(pte_t pte)325 extern inline int pte_dirty(pte_t pte) { return pte_val(pte) & _PAGE_DIRTY; }
pte_young(pte_t pte)326 extern inline int pte_young(pte_t pte) { return pte_val(pte) & _PAGE_ACCESSED; }
pte_write(pte_t pte)327 extern inline int pte_write(pte_t pte) { return pte_val(pte) & _PAGE_RW; }
328
pte_rdprotect(pte_t pte)329 extern inline pte_t pte_rdprotect(pte_t pte) { set_pte(&pte, __pte(pte_val(pte) & ~_PAGE_USER)); return pte; }
pte_exprotect(pte_t pte)330 extern inline pte_t pte_exprotect(pte_t pte) { set_pte(&pte, __pte(pte_val(pte) & ~_PAGE_USER)); return pte; }
pte_mkclean(pte_t pte)331 extern inline pte_t pte_mkclean(pte_t pte) { set_pte(&pte, __pte(pte_val(pte) & ~_PAGE_DIRTY)); return pte; }
pte_mkold(pte_t pte)332 extern inline pte_t pte_mkold(pte_t pte) { set_pte(&pte, __pte(pte_val(pte) & ~_PAGE_ACCESSED)); return pte; }
pte_wrprotect(pte_t pte)333 extern inline pte_t pte_wrprotect(pte_t pte) { set_pte(&pte, __pte(pte_val(pte) & ~_PAGE_RW)); return pte; }
pte_mkread(pte_t pte)334 extern inline pte_t pte_mkread(pte_t pte) { set_pte(&pte, __pte(pte_val(pte) | _PAGE_USER)); return pte; }
pte_mkexec(pte_t pte)335 extern inline pte_t pte_mkexec(pte_t pte) { set_pte(&pte, __pte(pte_val(pte) | _PAGE_USER)); return pte; }
pte_mkdirty(pte_t pte)336 extern inline pte_t pte_mkdirty(pte_t pte) { set_pte(&pte, __pte(pte_val(pte) | _PAGE_DIRTY)); return pte; }
pte_mkyoung(pte_t pte)337 extern inline pte_t pte_mkyoung(pte_t pte) { set_pte(&pte, __pte(pte_val(pte) | _PAGE_ACCESSED)); return pte; }
pte_mkwrite(pte_t pte)338 extern inline pte_t pte_mkwrite(pte_t pte) { set_pte(&pte, __pte(pte_val(pte) | _PAGE_RW)); return pte; }
ptep_test_and_clear_dirty(pte_t * ptep)339 static inline int ptep_test_and_clear_dirty(pte_t *ptep) { return test_and_clear_bit(_PAGE_BIT_DIRTY, ptep); }
ptep_test_and_clear_young(pte_t * ptep)340 static inline int ptep_test_and_clear_young(pte_t *ptep) { return test_and_clear_bit(_PAGE_BIT_ACCESSED, ptep); }
ptep_set_wrprotect(pte_t * ptep)341 static inline void ptep_set_wrprotect(pte_t *ptep) { clear_bit(_PAGE_BIT_RW, ptep); }
ptep_mkdirty(pte_t * ptep)342 static inline void ptep_mkdirty(pte_t *ptep) { set_bit(_PAGE_BIT_DIRTY, ptep); }
343
344 /*
345 * Conversion functions: convert a page and protection to a page entry,
346 * and a page entry and page directory to the page they refer to.
347 */
348
349 #define mk_pte(page,pgprot) \
350 ({ \
351 pte_t __pte; \
352 unsigned long __val = page_to_phys(page); \
353 __val |= pgprot_val(pgprot); \
354 __val &= __supported_pte_mask; \
355 set_pte(&__pte, __pte(__val)); \
356 __pte; \
357 })
358
359 /* This takes a physical page address that is used by the remapping functions */
mk_pte_phys(unsigned long physpage,pgprot_t pgprot)360 static inline pte_t mk_pte_phys(unsigned long physpage, pgprot_t pgprot)
361 {
362 pte_t __pte;
363 set_pte(&__pte, __pte(physpage + (pgprot_val(pgprot) & __supported_pte_mask)));
364 return __pte;
365 }
366
pte_modify(pte_t pte,pgprot_t newprot)367 extern inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
368 {
369 set_pte(&pte,
370 __pte(((pte_val(pte) & _PAGE_CHG_MASK) | pgprot_val(newprot)) &
371 __supported_pte_mask));
372 return pte;
373 }
374
375 #define page_pte(page) page_pte_prot(page, __pgprot(0))
376 #define __pmd_page(pmd) (__va(pmd_val(pmd) & PHYSICAL_PAGE_MASK))
377
378 /* to find an entry in a page-table-directory. */
379 #define pgd_index(address) ((address >> PGDIR_SHIFT) & (PTRS_PER_PGD-1))
380 #define pgd_offset(mm, address) ((mm)->pgd+pgd_index(address))
381
382 #define __pgd_offset_k(pgd, address) ((pgd) + pgd_index(address))
383
384 #define current_pgd_offset_k(address) \
385 __pgd_offset_k((pgd_t *)read_pda(level4_pgt), address)
386
387 /* This accesses the reference page table of the boot cpu.
388 Other CPUs get synced lazily via the page fault handler. */
389 #define pgd_offset_k(address) \
390 __pgd_offset_k( \
391 (pgd_t *)__va(pml4_val(init_level4_pgt[pml4_index(address)]) & PHYSICAL_PAGE_MASK), address)
392
393 #define __pmd_offset(address) \
394 (((address) >> PMD_SHIFT) & (PTRS_PER_PMD-1))
395
396 /* Find an entry in the third-level page table.. */
397 #define __pte_offset(address) \
398 ((address >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
399 #define pte_offset(dir, address) ((pte_t *) __pmd_page(*(dir)) + \
400 __pte_offset(address))
401
402 /* never use these in the common code */
403 #define pml4_page(level4) ((unsigned long) __va(pml4_val(level4) & PHYSICAL_PAGE_MASK))
404 #define pml4_index(address) (((address) >> PML4_SHIFT) & (PTRS_PER_PML4-1))
405 #define pml4_offset_k(address) ((pml4_t *)read_pda(level4_pgt) + pml4_index(address))
406 #define level3_offset_k(dir, address) ((pgd_t *) pml4_page(*(dir)) + pgd_index(address))
407 #define mk_kernel_pml4(address,prot) ((pml4_t){(address) | pgprot_val(prot)})
408 #define pml4_present(pml4) (pml4_val(pml4) & _PAGE_PRESENT)
409
410 /*
411 * x86 doesn't have any external MMU info: the kernel page
412 * tables contain all the necessary information.
413 */
414 #define update_mmu_cache(vma,address,pte) do { } while (0)
415
416 /* Encode and de-code a swap entry */
417 #define SWP_TYPE(x) (((x).val >> 1) & 0x3f)
418 #define SWP_OFFSET(x) ((x).val >> 8)
419 #define SWP_ENTRY(type, offset) ((swp_entry_t) { ((type) << 1) | ((offset) << 8) })
420 #define pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) })
421 #define swp_entry_to_pte(x) ((pte_t) { (x).val })
422
423 struct page;
424 /*
425 * Change attributes of an kernel page.
426 */
427 struct page;
428 extern int change_page_attr(struct page *page, int numpages, pgprot_t prot);
429
430 extern void clear_kernel_mapping(unsigned long addr, unsigned long size);
431
432 #endif /* !__ASSEMBLY__ */
433
434 /* Needs to be defined here and not in linux/mm.h, as it is arch dependent */
435 #define PageSkip(page) (0)
436 #define kern_addr_valid(kaddr) ((kaddr)>>PAGE_SHIFT < max_mapnr)
437
438 #define io_remap_page_range remap_page_range
439
440 #define HAVE_ARCH_UNMAPPED_AREA
441
442 #define pgtable_cache_init() do { } while (0)
443
444
445 #endif /* _X86_64_PGTABLE_H */
446