#define _ASM_GENERIC_PGTABLE_H
#ifndef __ASSEMBLY__
-
-#ifndef __HAVE_ARCH_PTEP_ESTABLISH
-/*
- * Establish a new mapping:
- * - flush the old one
- * - update the page tables
- * - inform the TLB about the new one
- *
- * We hold the mm semaphore for reading, and the pte lock.
- *
- * Note: the old pte is known to not be writable, so we don't need to
- * worry about dirty bits etc getting lost.
- */
-#ifndef __HAVE_ARCH_SET_PTE_ATOMIC
-#define ptep_establish(__vma, __address, __ptep, __entry) \
-do { \
- set_pte_at((__vma)->vm_mm, (__address), __ptep, __entry); \
- flush_tlb_page(__vma, __address); \
-} while (0)
-#else /* __HAVE_ARCH_SET_PTE_ATOMIC */
-#define ptep_establish(__vma, __address, __ptep, __entry) \
-do { \
- set_pte_atomic(__ptep, __entry); \
- flush_tlb_page(__vma, __address); \
-} while (0)
-#endif /* __HAVE_ARCH_SET_PTE_ATOMIC */
-#endif
+#ifdef CONFIG_MMU
#ifndef __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
/*
* Largely same as above, but only sets the access flags (dirty,
* accessed, and writable). Furthermore, we know it always gets set
* to a "more permissive" setting, which allows most architectures
- * to optimize this.
+ * to optimize this. We return whether the PTE actually changed, which
+ * in turn instructs the caller to do things like update__mmu_cache.
+ * This used to be done in the caller, but sparc needs minor faults to
+ * force that call on sun4c so we changed this macro slightly
*/
#define ptep_set_access_flags(__vma, __address, __ptep, __entry, __dirty) \
-do { \
- set_pte_at((__vma)->vm_mm, (__address), __ptep, __entry); \
- flush_tlb_page(__vma, __address); \
-} while (0)
+({ \
+ int __changed = !pte_same(*(__ptep), __entry); \
+ if (__changed) { \
+ set_pte_at((__vma)->vm_mm, (__address), __ptep, __entry); \
+ flush_tlb_page(__vma, __address); \
+ } \
+ __changed; \
+})
#endif
#ifndef __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
})
#endif
-#ifndef __HAVE_ARCH_PTEP_TEST_AND_CLEAR_DIRTY
-#define ptep_test_and_clear_dirty(__vma, __address, __ptep) \
-({ \
- pte_t __pte = *__ptep; \
- int r = 1; \
- if (!pte_dirty(__pte)) \
- r = 0; \
- else \
- set_pte_at((__vma)->vm_mm, (__address), (__ptep), \
- pte_mkclean(__pte)); \
- r; \
-})
-#endif
-
-#ifndef __HAVE_ARCH_PTEP_CLEAR_DIRTY_FLUSH
-#define ptep_clear_flush_dirty(__vma, __address, __ptep) \
-({ \
- int __dirty; \
- __dirty = ptep_test_and_clear_dirty(__vma, __address, __ptep); \
- if (__dirty) \
- flush_tlb_page(__vma, __address); \
- __dirty; \
-})
-#endif
-
#ifndef __HAVE_ARCH_PTEP_GET_AND_CLEAR
#define ptep_get_and_clear(__mm, __address, __ptep) \
({ \
})
#endif
-#ifndef __HAVE_ARCH_PTE_CLEAR_FULL
-#define pte_clear_full(__mm, __address, __ptep, __full) \
+/*
+ * Some architectures may be able to avoid expensive synchronization
+ * primitives when modifications are made to PTE's which are already
+ * not present, or in the process of an address space destruction.
+ */
+#ifndef __HAVE_ARCH_PTE_CLEAR_NOT_PRESENT_FULL
+#define pte_clear_not_present_full(__mm, __address, __ptep, __full) \
do { \
pte_clear((__mm), (__address), (__ptep)); \
} while (0)
#define pte_same(A,B) (pte_val(A) == pte_val(B))
#endif
-#ifndef __HAVE_ARCH_PAGE_TEST_AND_CLEAR_DIRTY
-#define page_test_and_clear_dirty(page) (0)
+#ifndef __HAVE_ARCH_PAGE_TEST_DIRTY
+#define page_test_dirty(page) (0)
+#endif
+
+#ifndef __HAVE_ARCH_PAGE_CLEAR_DIRTY
+#define page_clear_dirty(page) do { } while (0)
+#endif
+
+#ifndef __HAVE_ARCH_PAGE_TEST_DIRTY
#define pte_maybe_dirty(pte) pte_dirty(pte)
#else
#define pte_maybe_dirty(pte) (1)
#define pgd_offset_gate(mm, addr) pgd_offset(mm, addr)
#endif
-#ifndef __HAVE_ARCH_LAZY_MMU_PROT_UPDATE
-#define lazy_mmu_prot_update(pte) do { } while (0)
-#endif
-
#ifndef __HAVE_ARCH_MOVE_PTE
#define move_pte(pte, prot, old_addr, new_addr) (pte)
#endif
}
return 0;
}
+#endif /* CONFIG_MMU */
+
+/*
+ * A facility to provide lazy MMU batching. This allows PTE updates and
+ * page invalidations to be delayed until a call to leave lazy MMU mode
+ * is issued. Some architectures may benefit from doing this, and it is
+ * beneficial for both shadow and direct mode hypervisors, which may batch
+ * the PTE updates which happen during this window. Note that using this
+ * interface requires that read hazards be removed from the code. A read
+ * hazard could result in the direct mode hypervisor case, since the actual
+ * write to the page tables may not yet have taken place, so reads though
+ * a raw PTE pointer after it has been modified are not guaranteed to be
+ * up to date. This mode can only be entered and left under the protection of
+ * the page table locks for all page tables which may be modified. In the UP
+ * case, this is required so that preemption is disabled, and in the SMP case,
+ * it must synchronize the delayed page table writes properly on other CPUs.
+ */
+#ifndef __HAVE_ARCH_ENTER_LAZY_MMU_MODE
+#define arch_enter_lazy_mmu_mode() do {} while (0)
+#define arch_leave_lazy_mmu_mode() do {} while (0)
+#define arch_flush_lazy_mmu_mode() do {} while (0)
+#endif
+
+/*
+ * A facility to provide batching of the reload of page tables with the
+ * actual context switch code for paravirtualized guests. By convention,
+ * only one of the lazy modes (CPU, MMU) should be active at any given
+ * time, entry should never be nested, and entry and exits should always
+ * be paired. This is for sanity of maintaining and reasoning about the
+ * kernel code.
+ */
+#ifndef __HAVE_ARCH_ENTER_LAZY_CPU_MODE
+#define arch_enter_lazy_cpu_mode() do {} while (0)
+#define arch_leave_lazy_cpu_mode() do {} while (0)
+#define arch_flush_lazy_cpu_mode() do {} while (0)
+#endif
+
#endif /* !__ASSEMBLY__ */
#endif /* _ASM_GENERIC_PGTABLE_H */