RT-AC56 3.0.0.4.374.37 core
[tomato.git] / release / src-rt-6.x.4708 / linux / linux-2.6.36 / include / asm-generic / pgtable.h
blobe2bd73e8f9c0b4db75755d1e4f0aadaaa0e20c2a
1 #ifndef _ASM_GENERIC_PGTABLE_H
2 #define _ASM_GENERIC_PGTABLE_H
4 #ifndef __ASSEMBLY__
5 #ifdef CONFIG_MMU
7 #ifndef __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
8 /*
9 * Largely same as above, but only sets the access flags (dirty,
10 * accessed, and writable). Furthermore, we know it always gets set
11 * to a "more permissive" setting, which allows most architectures
12 * to optimize this. We return whether the PTE actually changed, which
13 * in turn instructs the caller to do things like update__mmu_cache.
14 * This used to be done in the caller, but sparc needs minor faults to
15 * force that call on sun4c so we changed this macro slightly
17 #define ptep_set_access_flags(__vma, __address, __ptep, __entry, __dirty) \
18 ({ \
19 int __changed = !pte_same(*(__ptep), __entry); \
20 if (__changed) { \
21 set_pte_at((__vma)->vm_mm, (__address), __ptep, __entry); \
22 flush_tlb_page(__vma, __address); \
23 } \
24 __changed; \
26 #endif
28 #ifndef __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
29 #define ptep_test_and_clear_young(__vma, __address, __ptep) \
30 ({ \
31 pte_t __pte = *(__ptep); \
32 int r = 1; \
33 if (!pte_young(__pte)) \
34 r = 0; \
35 else \
36 set_pte_at((__vma)->vm_mm, (__address), \
37 (__ptep), pte_mkold(__pte)); \
38 r; \
40 #endif
42 #ifndef __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSH
43 #define ptep_clear_flush_young(__vma, __address, __ptep) \
44 ({ \
45 int __young; \
46 __young = ptep_test_and_clear_young(__vma, __address, __ptep); \
47 if (__young) \
48 flush_tlb_page(__vma, __address); \
49 __young; \
51 #endif
53 #ifndef __HAVE_ARCH_PTEP_GET_AND_CLEAR
54 #define ptep_get_and_clear(__mm, __address, __ptep) \
55 ({ \
56 pte_t __pte = *(__ptep); \
57 pte_clear((__mm), (__address), (__ptep)); \
58 __pte; \
60 #endif
62 #ifndef __HAVE_ARCH_PTEP_GET_AND_CLEAR_FULL
63 #define ptep_get_and_clear_full(__mm, __address, __ptep, __full) \
64 ({ \
65 pte_t __pte; \
66 __pte = ptep_get_and_clear((__mm), (__address), (__ptep)); \
67 __pte; \
69 #endif
72 * Some architectures may be able to avoid expensive synchronization
73 * primitives when modifications are made to PTE's which are already
74 * not present, or in the process of an address space destruction.
76 #ifndef __HAVE_ARCH_PTE_CLEAR_NOT_PRESENT_FULL
77 #define pte_clear_not_present_full(__mm, __address, __ptep, __full) \
78 do { \
79 pte_clear((__mm), (__address), (__ptep)); \
80 } while (0)
81 #endif
83 #ifndef __HAVE_ARCH_PTEP_CLEAR_FLUSH
84 #define ptep_clear_flush(__vma, __address, __ptep) \
85 ({ \
86 pte_t __pte; \
87 __pte = ptep_get_and_clear((__vma)->vm_mm, __address, __ptep); \
88 flush_tlb_page(__vma, __address); \
89 __pte; \
91 #endif
93 #ifndef __HAVE_ARCH_PTEP_SET_WRPROTECT
94 struct mm_struct;
95 static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long address, pte_t *ptep)
97 pte_t old_pte = *ptep;
98 set_pte_at(mm, address, ptep, pte_wrprotect(old_pte));
100 #endif
102 #ifndef __HAVE_ARCH_PTE_SAME
103 #define pte_same(A,B) (pte_val(A) == pte_val(B))
104 #endif
106 #ifndef __HAVE_ARCH_PAGE_TEST_DIRTY
107 #define page_test_dirty(page) (0)
108 #endif
110 #ifndef __HAVE_ARCH_PAGE_CLEAR_DIRTY
111 #define page_clear_dirty(page) do { } while (0)
112 #endif
114 #ifndef __HAVE_ARCH_PAGE_TEST_DIRTY
115 #define pte_maybe_dirty(pte) pte_dirty(pte)
116 #else
117 #define pte_maybe_dirty(pte) (1)
118 #endif
120 #ifndef __HAVE_ARCH_PAGE_TEST_AND_CLEAR_YOUNG
121 #define page_test_and_clear_young(page) (0)
122 #endif
124 #ifndef __HAVE_ARCH_PGD_OFFSET_GATE
125 #define pgd_offset_gate(mm, addr) pgd_offset(mm, addr)
126 #endif
128 #ifndef __HAVE_ARCH_MOVE_PTE
129 #define move_pte(pte, prot, old_addr, new_addr) (pte)
130 #endif
132 #ifndef pgprot_noncached
133 #define pgprot_noncached(prot) (prot)
134 #endif
136 #ifndef pgprot_writecombine
137 #define pgprot_writecombine pgprot_noncached
138 #endif
141 * When walking page tables, get the address of the next boundary,
142 * or the end address of the range if that comes earlier. Although no
143 * vma end wraps to 0, rounded up __boundary may wrap to 0 throughout.
146 #define pgd_addr_end(addr, end) \
147 ({ unsigned long __boundary = ((addr) + PGDIR_SIZE) & PGDIR_MASK; \
148 (__boundary - 1 < (end) - 1)? __boundary: (end); \
151 #ifndef pud_addr_end
152 #define pud_addr_end(addr, end) \
153 ({ unsigned long __boundary = ((addr) + PUD_SIZE) & PUD_MASK; \
154 (__boundary - 1 < (end) - 1)? __boundary: (end); \
156 #endif
158 #ifndef pmd_addr_end
159 #define pmd_addr_end(addr, end) \
160 ({ unsigned long __boundary = ((addr) + PMD_SIZE) & PMD_MASK; \
161 (__boundary - 1 < (end) - 1)? __boundary: (end); \
163 #endif
166 * When walking page tables, we usually want to skip any p?d_none entries;
167 * and any p?d_bad entries - reporting the error before resetting to none.
168 * Do the tests inline, but report and clear the bad entry in mm/memory.c.
170 void pgd_clear_bad(pgd_t *);
171 void pud_clear_bad(pud_t *);
172 void pmd_clear_bad(pmd_t *);
174 static inline int pgd_none_or_clear_bad(pgd_t *pgd)
176 if (pgd_none(*pgd))
177 return 1;
178 if (unlikely(pgd_bad(*pgd))) {
179 pgd_clear_bad(pgd);
180 return 1;
182 return 0;
185 static inline int pud_none_or_clear_bad(pud_t *pud)
187 if (pud_none(*pud))
188 return 1;
189 if (unlikely(pud_bad(*pud))) {
190 pud_clear_bad(pud);
191 return 1;
193 return 0;
196 static inline int pmd_none_or_clear_bad(pmd_t *pmd)
198 if (pmd_none(*pmd))
199 return 1;
200 if (unlikely(pmd_bad(*pmd))) {
201 pmd_clear_bad(pmd);
202 return 1;
204 return 0;
207 static inline pte_t __ptep_modify_prot_start(struct mm_struct *mm,
208 unsigned long addr,
209 pte_t *ptep)
212 * Get the current pte state, but zero it out to make it
213 * non-present, preventing the hardware from asynchronously
214 * updating it.
216 return ptep_get_and_clear(mm, addr, ptep);
219 static inline void __ptep_modify_prot_commit(struct mm_struct *mm,
220 unsigned long addr,
221 pte_t *ptep, pte_t pte)
224 * The pte is non-present, so there's no hardware state to
225 * preserve.
227 set_pte_at(mm, addr, ptep, pte);
230 #ifndef __HAVE_ARCH_PTEP_MODIFY_PROT_TRANSACTION
232 * Start a pte protection read-modify-write transaction, which
233 * protects against asynchronous hardware modifications to the pte.
234 * The intention is not to prevent the hardware from making pte
235 * updates, but to prevent any updates it may make from being lost.
237 * This does not protect against other software modifications of the
238 * pte; the appropriate pte lock must be held over the transation.
240 * Note that this interface is intended to be batchable, meaning that
241 * ptep_modify_prot_commit may not actually update the pte, but merely
242 * queue the update to be done at some later time. The update must be
243 * actually committed before the pte lock is released, however.
245 static inline pte_t ptep_modify_prot_start(struct mm_struct *mm,
246 unsigned long addr,
247 pte_t *ptep)
249 return __ptep_modify_prot_start(mm, addr, ptep);
253 * Commit an update to a pte, leaving any hardware-controlled bits in
254 * the PTE unmodified.
256 static inline void ptep_modify_prot_commit(struct mm_struct *mm,
257 unsigned long addr,
258 pte_t *ptep, pte_t pte)
260 __ptep_modify_prot_commit(mm, addr, ptep, pte);
262 #endif /* __HAVE_ARCH_PTEP_MODIFY_PROT_TRANSACTION */
263 #endif /* CONFIG_MMU */
266 * A facility to provide lazy MMU batching. This allows PTE updates and
267 * page invalidations to be delayed until a call to leave lazy MMU mode
268 * is issued. Some architectures may benefit from doing this, and it is
269 * beneficial for both shadow and direct mode hypervisors, which may batch
270 * the PTE updates which happen during this window. Note that using this
271 * interface requires that read hazards be removed from the code. A read
272 * hazard could result in the direct mode hypervisor case, since the actual
273 * write to the page tables may not yet have taken place, so reads though
274 * a raw PTE pointer after it has been modified are not guaranteed to be
275 * up to date. This mode can only be entered and left under the protection of
276 * the page table locks for all page tables which may be modified. In the UP
277 * case, this is required so that preemption is disabled, and in the SMP case,
278 * it must synchronize the delayed page table writes properly on other CPUs.
280 #ifndef __HAVE_ARCH_ENTER_LAZY_MMU_MODE
281 #define arch_enter_lazy_mmu_mode() do {} while (0)
282 #define arch_leave_lazy_mmu_mode() do {} while (0)
283 #define arch_flush_lazy_mmu_mode() do {} while (0)
284 #endif
287 * A facility to provide batching of the reload of page tables and
288 * other process state with the actual context switch code for
289 * paravirtualized guests. By convention, only one of the batched
290 * update (lazy) modes (CPU, MMU) should be active at any given time,
291 * entry should never be nested, and entry and exits should always be
292 * paired. This is for sanity of maintaining and reasoning about the
293 * kernel code. In this case, the exit (end of the context switch) is
294 * in architecture-specific code, and so doesn't need a generic
295 * definition.
297 #ifndef __HAVE_ARCH_START_CONTEXT_SWITCH
298 #define arch_start_context_switch(prev) do {} while (0)
299 #endif
301 #ifndef __HAVE_PFNMAP_TRACKING
303 * Interface that can be used by architecture code to keep track of
304 * memory type of pfn mappings (remap_pfn_range, vm_insert_pfn)
306 * track_pfn_vma_new is called when a _new_ pfn mapping is being established
307 * for physical range indicated by pfn and size.
309 static inline int track_pfn_vma_new(struct vm_area_struct *vma, pgprot_t *prot,
310 unsigned long pfn, unsigned long size)
312 return 0;
316 * Interface that can be used by architecture code to keep track of
317 * memory type of pfn mappings (remap_pfn_range, vm_insert_pfn)
319 * track_pfn_vma_copy is called when vma that is covering the pfnmap gets
320 * copied through copy_page_range().
322 static inline int track_pfn_vma_copy(struct vm_area_struct *vma)
324 return 0;
328 * Interface that can be used by architecture code to keep track of
329 * memory type of pfn mappings (remap_pfn_range, vm_insert_pfn)
331 * untrack_pfn_vma is called while unmapping a pfnmap for a region.
332 * untrack can be called for a specific region indicated by pfn and size or
333 * can be for the entire vma (in which case size can be zero).
335 static inline void untrack_pfn_vma(struct vm_area_struct *vma,
336 unsigned long pfn, unsigned long size)
339 #else
340 extern int track_pfn_vma_new(struct vm_area_struct *vma, pgprot_t *prot,
341 unsigned long pfn, unsigned long size);
342 extern int track_pfn_vma_copy(struct vm_area_struct *vma);
343 extern void untrack_pfn_vma(struct vm_area_struct *vma, unsigned long pfn,
344 unsigned long size);
345 #endif
347 #endif /* !__ASSEMBLY__ */
349 #endif /* _ASM_GENERIC_PGTABLE_H */