1 #ifndef _I386_PGTABLE_H
2 #define _I386_PGTABLE_H
4 #include <linux/config.h>
5 #include <asm/hypervisor.h>
8 * The Linux memory management assumes a three-level page table setup. On
9 * the i386, we use that, but "fold" the mid level into the top-level page
10 * table, so that we physically have the same two-level page table as the
13 * This file contains the functions and defines necessary to modify and use
14 * the i386 page table tree.
17 #include <asm/processor.h>
18 #include <asm/fixmap.h>
19 #include <linux/threads.h>
21 #ifndef _I386_BITOPS_H
22 #include <asm/bitops.h>
25 #include <linux/slab.h>
26 #include <linux/list.h>
27 #include <linux/spinlock.h>
30 struct vm_area_struct;
33 * ZERO_PAGE is a global shared page that is always zero: used
34 * for zero-mapped memory areas etc..
36 #define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page))
37 extern unsigned long empty_zero_page[1024];
38 extern pgd_t *swapper_pg_dir;
39 extern kmem_cache_t *pgd_cache;
40 extern kmem_cache_t *pmd_cache;
41 extern spinlock_t pgd_lock;
42 extern struct page *pgd_list;
44 void pmd_ctor(void *, kmem_cache_t *, unsigned long);
45 void pgd_ctor(void *, kmem_cache_t *, unsigned long);
46 void pgd_dtor(void *, kmem_cache_t *, unsigned long);
47 void pgtable_cache_init(void);
48 void paging_init(void);
51 * The Linux x86 paging architecture is 'compile-time dual-mode', it
52 * implements both the traditional 2-level x86 page tables and the
53 * newer 3-level PAE-mode page tables.
56 # include <asm/pgtable-3level-defs.h>
57 # define PMD_SIZE (1UL << PMD_SHIFT)
58 # define PMD_MASK (~(PMD_SIZE-1))
60 # include <asm/pgtable-2level-defs.h>
63 #define PGDIR_SIZE (1UL << PGDIR_SHIFT)
64 #define PGDIR_MASK (~(PGDIR_SIZE-1))
66 #define USER_PTRS_PER_PGD (TASK_SIZE/PGDIR_SIZE)
67 #define FIRST_USER_ADDRESS 0
69 #define USER_PGD_PTRS (PAGE_OFFSET >> PGDIR_SHIFT)
70 #define KERNEL_PGD_PTRS (PTRS_PER_PGD-USER_PGD_PTRS)
72 #define TWOLEVEL_PGDIR_SHIFT 22
73 #define BOOT_USER_PGD_PTRS (__PAGE_OFFSET >> TWOLEVEL_PGDIR_SHIFT)
74 #define BOOT_KERNEL_PGD_PTRS (1024-BOOT_USER_PGD_PTRS)
76 /* Just any arbitrary offset to the start of the vmalloc VM area: the
77 * current 8MB value just means that there will be a 8MB "hole" after the
78 * physical memory until the kernel virtual memory starts. That means that
79 * any out-of-bounds memory accesses will hopefully be caught.
80 * The vmalloc() routines leaves a hole of 4kB between each vmalloced
81 * area for the same reason. ;)
83 #define VMALLOC_OFFSET (8*1024*1024)
84 #define VMALLOC_START (((unsigned long) high_memory + vmalloc_earlyreserve + \
85 2*VMALLOC_OFFSET-1) & ~(VMALLOC_OFFSET-1))
87 # define VMALLOC_END (PKMAP_BASE-2*PAGE_SIZE)
89 # define VMALLOC_END (FIXADDR_START-2*PAGE_SIZE)
93 * _PAGE_PSE set in the page directory entry just means that
94 * the page directory entry points directly to a 4MB-aligned block of
97 #define _PAGE_BIT_PRESENT 0
98 #define _PAGE_BIT_RW 1
99 #define _PAGE_BIT_USER 2
100 #define _PAGE_BIT_PWT 3
101 #define _PAGE_BIT_PCD 4
102 #define _PAGE_BIT_ACCESSED 5
103 #define _PAGE_BIT_DIRTY 6
104 #define _PAGE_BIT_PSE 7 /* 4 MB (or 2MB) page, Pentium+, if present.. */
105 #define _PAGE_BIT_GLOBAL 8 /* Global TLB entry PPro+ */
106 #define _PAGE_BIT_UNUSED1 9 /* available for programmer */
107 #define _PAGE_BIT_UNUSED2 10
108 #define _PAGE_BIT_UNUSED3 11
109 #define _PAGE_BIT_NX 63
111 #define _PAGE_PRESENT 0x001
112 #define _PAGE_RW 0x002
113 #define _PAGE_USER 0x004
114 #define _PAGE_PWT 0x008
115 #define _PAGE_PCD 0x010
116 #define _PAGE_ACCESSED 0x020
117 #define _PAGE_DIRTY 0x040
118 #define _PAGE_PSE 0x080 /* 4 MB (or 2MB) page, Pentium+, if present.. */
119 #define _PAGE_GLOBAL 0x100 /* Global TLB entry PPro+ */
120 #define _PAGE_UNUSED1 0x200 /* available for programmer */
121 #define _PAGE_UNUSED2 0x400
122 #define _PAGE_UNUSED3 0x800
124 /* If _PAGE_PRESENT is clear, we use these: */
125 #define _PAGE_FILE 0x040 /* nonlinear file mapping, saved PTE; unset:swap */
126 #define _PAGE_PROTNONE 0x080 /* if the user mapped it with PROT_NONE;
127 pte_present gives true */
128 #ifdef CONFIG_X86_PAE
129 #define _PAGE_NX (1ULL<<_PAGE_BIT_NX)
134 #define _PAGE_TABLE (_PAGE_PRESENT | _PAGE_RW | _PAGE_USER | _PAGE_ACCESSED | _PAGE_DIRTY)
135 #define _KERNPG_TABLE (_PAGE_PRESENT | _PAGE_RW | _PAGE_ACCESSED | _PAGE_DIRTY)
136 #define _PAGE_CHG_MASK (PTE_MASK | _PAGE_ACCESSED | _PAGE_DIRTY)
139 __pgprot(_PAGE_PROTNONE | _PAGE_ACCESSED)
140 #define PAGE_SHARED \
141 __pgprot(_PAGE_PRESENT | _PAGE_RW | _PAGE_USER | _PAGE_ACCESSED)
143 #define PAGE_SHARED_EXEC \
144 __pgprot(_PAGE_PRESENT | _PAGE_RW | _PAGE_USER | _PAGE_ACCESSED)
145 #define PAGE_COPY_NOEXEC \
146 __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_ACCESSED | _PAGE_NX)
147 #define PAGE_COPY_EXEC \
148 __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_ACCESSED)
151 #define PAGE_READONLY \
152 __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_ACCESSED | _PAGE_NX)
153 #define PAGE_READONLY_EXEC \
154 __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_ACCESSED)
156 #define _PAGE_KERNEL \
157 (_PAGE_PRESENT | _PAGE_RW | _PAGE_DIRTY | _PAGE_ACCESSED | _PAGE_NX)
158 #define _PAGE_KERNEL_EXEC \
159 (_PAGE_PRESENT | _PAGE_RW | _PAGE_DIRTY | _PAGE_ACCESSED)
161 extern unsigned long long __PAGE_KERNEL, __PAGE_KERNEL_EXEC;
162 #define __PAGE_KERNEL_RO (__PAGE_KERNEL & ~_PAGE_RW)
163 #define __PAGE_KERNEL_NOCACHE (__PAGE_KERNEL | _PAGE_PCD)
164 #define __PAGE_KERNEL_LARGE (__PAGE_KERNEL | _PAGE_PSE)
165 #define __PAGE_KERNEL_LARGE_EXEC (__PAGE_KERNEL_EXEC | _PAGE_PSE)
167 #define PAGE_KERNEL __pgprot(__PAGE_KERNEL)
168 #define PAGE_KERNEL_RO __pgprot(__PAGE_KERNEL_RO)
169 #define PAGE_KERNEL_EXEC __pgprot(__PAGE_KERNEL_EXEC)
170 #define PAGE_KERNEL_NOCACHE __pgprot(__PAGE_KERNEL_NOCACHE)
171 #define PAGE_KERNEL_LARGE __pgprot(__PAGE_KERNEL_LARGE)
172 #define PAGE_KERNEL_LARGE_EXEC __pgprot(__PAGE_KERNEL_LARGE_EXEC)
175 * The i386 can't do page protection for execute, and considers that
176 * the same are read. Also, write permissions imply read permissions.
177 * This is the closest we can get..
179 #define __P000 PAGE_NONE
180 #define __P001 PAGE_READONLY
181 #define __P010 PAGE_COPY
182 #define __P011 PAGE_COPY
183 #define __P100 PAGE_READONLY_EXEC
184 #define __P101 PAGE_READONLY_EXEC
185 #define __P110 PAGE_COPY_EXEC
186 #define __P111 PAGE_COPY_EXEC
188 #define __S000 PAGE_NONE
189 #define __S001 PAGE_READONLY
190 #define __S010 PAGE_SHARED
191 #define __S011 PAGE_SHARED
192 #define __S100 PAGE_READONLY_EXEC
193 #define __S101 PAGE_READONLY_EXEC
194 #define __S110 PAGE_SHARED_EXEC
195 #define __S111 PAGE_SHARED_EXEC
198 * Define this if things work differently on an i386 and an i486:
199 * it will (on an i486) warn about kernel memory accesses that are
200 * done without a 'access_ok(VERIFY_WRITE,..)'
202 #undef TEST_ACCESS_OK
204 /* The boot page tables (all created as a single array) */
205 extern unsigned long pg0[];
207 #define pte_present(x) ((x).pte_low & (_PAGE_PRESENT | _PAGE_PROTNONE))
209 /* To avoid harmful races, pmd_none(x) should check only the lower when PAE */
210 #define pmd_none(x) (!(unsigned long)pmd_val(x))
211 /* pmd_present doesn't just test the _PAGE_PRESENT bit since wr.p.t.
212 can temporarily clear it. */
213 #define pmd_present(x) (pmd_val(x))
214 #define pmd_bad(x) ((pmd_val(x) & (~PAGE_MASK & ~_PAGE_USER & ~_PAGE_PRESENT)) != (_KERNPG_TABLE & ~_PAGE_PRESENT))
217 #define pages_to_mb(x) ((x) >> (20-PAGE_SHIFT))
220 * The following only work if pte_present() is true.
221 * Undefined behaviour if not..
223 static inline int pte_user(pte_t pte) { return (pte).pte_low & _PAGE_USER; }
224 static inline int pte_read(pte_t pte) { return (pte).pte_low & _PAGE_USER; }
225 static inline int pte_dirty(pte_t pte) { return (pte).pte_low & _PAGE_DIRTY; }
226 static inline int pte_young(pte_t pte) { return (pte).pte_low & _PAGE_ACCESSED; }
227 static inline int pte_write(pte_t pte) { return (pte).pte_low & _PAGE_RW; }
228 static inline int pte_huge(pte_t pte) { return (pte).pte_low & _PAGE_PSE; }
231 * The following only works if pte_present() is not true.
233 static inline int pte_file(pte_t pte) { return (pte).pte_low & _PAGE_FILE; }
235 static inline pte_t pte_rdprotect(pte_t pte) { (pte).pte_low &= ~_PAGE_USER; return pte; }
236 static inline pte_t pte_exprotect(pte_t pte) { (pte).pte_low &= ~_PAGE_USER; return pte; }
237 static inline pte_t pte_mkclean(pte_t pte) { (pte).pte_low &= ~_PAGE_DIRTY; return pte; }
238 static inline pte_t pte_mkold(pte_t pte) { (pte).pte_low &= ~_PAGE_ACCESSED; return pte; }
239 static inline pte_t pte_wrprotect(pte_t pte) { (pte).pte_low &= ~_PAGE_RW; return pte; }
240 static inline pte_t pte_mkread(pte_t pte) { (pte).pte_low |= _PAGE_USER; return pte; }
241 static inline pte_t pte_mkexec(pte_t pte) { (pte).pte_low |= _PAGE_USER; return pte; }
242 static inline pte_t pte_mkdirty(pte_t pte) { (pte).pte_low |= _PAGE_DIRTY; return pte; }
243 static inline pte_t pte_mkyoung(pte_t pte) { (pte).pte_low |= _PAGE_ACCESSED; return pte; }
244 static inline pte_t pte_mkwrite(pte_t pte) { (pte).pte_low |= _PAGE_RW; return pte; }
245 static inline pte_t pte_mkhuge(pte_t pte) { (pte).pte_low |= _PAGE_PSE; return pte; }
247 #ifdef CONFIG_X86_PAE
248 # include <asm/pgtable-3level.h>
250 # include <asm/pgtable-2level.h>
253 static inline int ptep_test_and_clear_dirty(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep)
255 if (!pte_dirty(*ptep))
257 return test_and_clear_bit(_PAGE_BIT_DIRTY, &ptep->pte_low);
260 static inline int ptep_test_and_clear_young(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep)
262 if (!pte_young(*ptep))
264 return test_and_clear_bit(_PAGE_BIT_ACCESSED, &ptep->pte_low);
267 static inline pte_t ptep_get_and_clear_full(struct mm_struct *mm, unsigned long addr, pte_t *ptep, int full)
272 pte_clear(mm, addr, ptep);
274 pte = ptep_get_and_clear(mm, addr, ptep);
279 static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
281 if (pte_write(*ptep))
282 clear_bit(_PAGE_BIT_RW, &ptep->pte_low);
286 * clone_pgd_range(pgd_t *dst, pgd_t *src, int count);
288 * dst - pointer to pgd range anwhere on a pgd page
290 * count - the number of pgds to copy.
292 * dst and src can be on the same page, but the range must not overlap,
293 * and must not cross a page boundary.
295 static inline void clone_pgd_range(pgd_t *dst, pgd_t *src, int count)
297 memcpy(dst, src, count * sizeof(pgd_t));
301 * Macro to mark a page protection value as "uncacheable". On processors which do not support
302 * it, this is a no-op.
304 #define pgprot_noncached(prot) ((boot_cpu_data.x86 > 3) \
305 ? (__pgprot(pgprot_val(prot) | _PAGE_PCD | _PAGE_PWT)) : (prot))
308 * Conversion functions: convert a page and protection to a page entry,
309 * and a page entry and page directory to the page they refer to.
312 #define mk_pte(page, pgprot) pfn_pte(page_to_pfn(page), (pgprot))
314 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
316 pte.pte_low &= _PAGE_CHG_MASK;
317 pte.pte_low |= pgprot_val(newprot);
318 #ifdef CONFIG_X86_PAE
320 * Chop off the NX bit (if present), and add the NX portion of
321 * the newprot (if present):
323 pte.pte_high &= ~(1 << (_PAGE_BIT_NX - 32));
324 pte.pte_high |= (pgprot_val(newprot) >> 32) & \
325 (__supported_pte_mask >> 32);
330 #define pmd_large(pmd) \
331 ((pmd_val(pmd) & (_PAGE_PSE|_PAGE_PRESENT)) == (_PAGE_PSE|_PAGE_PRESENT))
334 * the pgd page can be thought of an array like this: pgd_t[PTRS_PER_PGD]
336 * this macro returns the index of the entry in the pgd page which would
337 * control the given virtual address
339 #define pgd_index(address) (((address) >> PGDIR_SHIFT) & (PTRS_PER_PGD-1))
340 #define pgd_index_k(addr) pgd_index(addr)
343 * pgd_offset() returns a (pgd_t *)
344 * pgd_index() is used get the offset into the pgd page's array of pgd_t's;
346 #define pgd_offset(mm, address) ((mm)->pgd+pgd_index(address))
349 * a shortcut which implies the use of the kernel's pgd, instead
352 #define pgd_offset_k(address) pgd_offset(&init_mm, address)
355 * the pmd page can be thought of an array like this: pmd_t[PTRS_PER_PMD]
357 * this macro returns the index of the entry in the pmd page which would
358 * control the given virtual address
360 #define pmd_index(address) \
361 (((address) >> PMD_SHIFT) & (PTRS_PER_PMD-1))
364 * the pte page can be thought of an array like this: pte_t[PTRS_PER_PTE]
366 * this macro returns the index of the entry in the pte page which would
367 * control the given virtual address
369 #define pte_index(address) \
370 (((address) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
371 #define pte_offset_kernel(dir, address) \
372 ((pte_t *) pmd_page_kernel(*(dir)) + pte_index(address))
374 #define pmd_page(pmd) (pfn_to_page(pmd_val(pmd) >> PAGE_SHIFT))
376 #define pmd_page_kernel(pmd) \
377 ((unsigned long) __va(pmd_val(pmd) & PAGE_MASK))
380 * Helper function that returns the kernel pagetable entry controlling
381 * the virtual address 'address'. NULL means no pagetable entry present.
382 * NOTE: the return type is pte_t but if the pmd is PSE then we return it
385 extern pte_t *lookup_address(unsigned long address);
388 * Make a given kernel text page executable/non-executable.
389 * Returns the previous executability setting of that page (which
390 * is used to restore the previous state). Used by the SMP bootup code.
391 * NOTE: this is an __init function for security reasons.
393 #ifdef CONFIG_X86_PAE
394 extern int set_kernel_exec(unsigned long vaddr, int enable);
396 static inline int set_kernel_exec(unsigned long vaddr, int enable) { return 0;}
399 extern void noexec_setup(const char *str);
401 #if defined(CONFIG_HIGHPTE)
402 #define pte_offset_map(dir, address) \
403 ((pte_t *)kmap_atomic_pte(pmd_page(*(dir)),KM_PTE0) + \
405 #define pte_offset_map_nested(dir, address) \
406 ((pte_t *)kmap_atomic_pte(pmd_page(*(dir)),KM_PTE1) + \
408 #define pte_unmap(pte) kunmap_atomic(pte, KM_PTE0)
409 #define pte_unmap_nested(pte) kunmap_atomic(pte, KM_PTE1)
411 #define pte_offset_map(dir, address) \
412 ((pte_t *)page_address(pmd_page(*(dir))) + pte_index(address))
413 #define pte_offset_map_nested(dir, address) pte_offset_map(dir, address)
414 #define pte_unmap(pte) do { } while (0)
415 #define pte_unmap_nested(pte) do { } while (0)
419 * The i386 doesn't have any external MMU info: the kernel page
420 * tables contain all the necessary information.
422 * Also, we only update the dirty/accessed state if we set
423 * the dirty bit by hand in the kernel, since the hardware
424 * will do the accessed bit for us, and we don't want to
425 * race with other CPU's that might be updating the dirty
426 * bit at the same time.
428 #define update_mmu_cache(vma,address,pte) do { } while (0)
429 #define __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
430 #define ptep_set_access_flags(__vma, __address, __ptep, __entry, __dirty) \
433 if ( likely((__vma)->vm_mm == current->mm) ) { \
434 BUG_ON(HYPERVISOR_update_va_mapping((__address), (__entry), UVMF_INVLPG|UVMF_MULTI|(unsigned long)((__vma)->vm_mm->cpu_vm_mask.bits))); \
436 xen_l1_entry_update((__ptep), (__entry)); \
437 flush_tlb_page((__vma), (__address)); \
442 #define __HAVE_ARCH_PTEP_ESTABLISH
443 #define ptep_establish(__vma, __address, __ptep, __entry) \
445 ptep_set_access_flags(__vma, __address, __ptep, __entry, 1); \
448 #include <xen/features.h>
449 void make_lowmem_page_readonly(void *va, unsigned int feature);
450 void make_lowmem_page_writable(void *va, unsigned int feature);
451 void make_page_readonly(void *va, unsigned int feature);
452 void make_page_writable(void *va, unsigned int feature);
453 void make_pages_readonly(void *va, unsigned int nr, unsigned int feature);
454 void make_pages_writable(void *va, unsigned int nr, unsigned int feature);
456 #define virt_to_ptep(__va) \
458 pgd_t *__pgd = pgd_offset_k((unsigned long)(__va)); \
459 pud_t *__pud = pud_offset(__pgd, (unsigned long)(__va)); \
460 pmd_t *__pmd = pmd_offset(__pud, (unsigned long)(__va)); \
461 pte_offset_kernel(__pmd, (unsigned long)(__va)); \
464 #define arbitrary_virt_to_machine(__va) \
466 maddr_t m = (maddr_t)pte_mfn(*virt_to_ptep(__va)) << PAGE_SHIFT;\
467 m | ((unsigned long)(__va) & (PAGE_SIZE-1)); \
470 #endif /* !__ASSEMBLY__ */
472 #ifdef CONFIG_FLATMEM
473 #define kern_addr_valid(addr) (1)
474 #endif /* CONFIG_FLATMEM */
476 int direct_remap_pfn_range(struct vm_area_struct *vma,
477 unsigned long address,
482 int direct_kernel_remap_pfn_range(unsigned long address,
487 int create_lookup_pte_addr(struct mm_struct *mm,
488 unsigned long address,
490 int touch_pte_range(struct mm_struct *mm,
491 unsigned long address,
494 #define io_remap_pfn_range(vma,from,pfn,size,prot) \
495 direct_remap_pfn_range(vma,from,pfn,size,prot,DOMID_IO)
497 #define MK_IOSPACE_PFN(space, pfn) (pfn)
498 #define GET_IOSPACE(pfn) 0
499 #define GET_PFN(pfn) (pfn)
501 #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
502 #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_DIRTY
503 #define __HAVE_ARCH_PTEP_GET_AND_CLEAR
504 #define __HAVE_ARCH_PTEP_GET_AND_CLEAR_FULL
505 #define __HAVE_ARCH_PTEP_SET_WRPROTECT
506 #define __HAVE_ARCH_PTE_SAME
507 #include <asm-generic/pgtable.h>
509 #endif /* _I386_PGTABLE_H */