X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=include%2Fasm-generic%2Fpgtable.h;h=dc8f99ee305fc4edd43232abdc0e5564b2c15434;hb=c58b8e4a25a1ba347a0e5d21984c97bd296f1691;hp=349260cd86ededc1487131a77518f6dc6187da8e;hpb=b278240839e20fa9384ea430df463b367b90e04e;p=pandora-kernel.git

diff --git a/include/asm-generic/pgtable.h b/include/asm-generic/pgtable.h
index 349260cd86ed..dc8f99ee305f 100644
--- a/include/asm-generic/pgtable.h
+++ b/include/asm-generic/pgtable.h
@@ -15,19 +15,11 @@
  * 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
 
 #ifndef __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
@@ -112,8 +104,13 @@ do {				  					  \
 })
 #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)
@@ -142,8 +139,15 @@ static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addres
 #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)
@@ -165,6 +169,41 @@ static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addres
 #define move_pte(pte, prot, old_addr, new_addr)	(pte)
 #endif
 
+/*
+ * 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
+
 /*
  * When walking page tables, get the address of the next boundary,
  * or the end address of the range if that comes earlier.  Although no