X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?p=pandora-kernel.git;a=blobdiff_plain;f=include%2Fasm-generic%2Fpgtable.h;h=4fce3db2cecceefbc68785fa105345f6f60d502b;hp=5f0d797d33fd9023df37f39ace04f800f0d8189e;hb=d59fdcf2ac501de99c3dfb452af5e254d4342886;hpb=886c81834884ed3df0d8cfc613d65441226786c8

diff --git a/include/asm-generic/pgtable.h b/include/asm-generic/pgtable.h
index 5f0d797d33fd..4fce3db2cecc 100644
--- a/include/asm-generic/pgtable.h
+++ b/include/asm-generic/pgtable.h
@@ -125,10 +125,6 @@ static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addres
 #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
@@ -201,6 +197,63 @@ static inline int pmd_none_or_clear_bad(pmd_t *pmd)
 }
 #endif /* CONFIG_MMU */
 
+static inline pte_t __ptep_modify_prot_start(struct mm_struct *mm,
+					     unsigned long addr,
+					     pte_t *ptep)
+{
+	/*
+	 * Get the current pte state, but zero it out to make it
+	 * non-present, preventing the hardware from asynchronously
+	 * updating it.
+	 */
+	return ptep_get_and_clear(mm, addr, ptep);
+}
+
+static inline void __ptep_modify_prot_commit(struct mm_struct *mm,
+					     unsigned long addr,
+					     pte_t *ptep, pte_t pte)
+{
+	/*
+	 * The pte is non-present, so there's no hardware state to
+	 * preserve.
+	 */
+	set_pte_at(mm, addr, ptep, pte);
+}
+
+#ifndef __HAVE_ARCH_PTEP_MODIFY_PROT_TRANSACTION
+/*
+ * Start a pte protection read-modify-write transaction, which
+ * protects against asynchronous hardware modifications to the pte.
+ * The intention is not to prevent the hardware from making pte
+ * updates, but to prevent any updates it may make from being lost.
+ *
+ * This does not protect against other software modifications of the
+ * pte; the appropriate pte lock must be held over the transation.
+ *
+ * Note that this interface is intended to be batchable, meaning that
+ * ptep_modify_prot_commit may not actually update the pte, but merely
+ * queue the update to be done at some later time.  The update must be
+ * actually committed before the pte lock is released, however.
+ */
+static inline pte_t ptep_modify_prot_start(struct mm_struct *mm,
+					   unsigned long addr,
+					   pte_t *ptep)
+{
+	return __ptep_modify_prot_start(mm, addr, ptep);
+}
+
+/*
+ * Commit an update to a pte, leaving any hardware-controlled bits in
+ * the PTE unmodified.
+ */
+static inline void ptep_modify_prot_commit(struct mm_struct *mm,
+					   unsigned long addr,
+					   pte_t *ptep, pte_t pte)
+{
+	__ptep_modify_prot_commit(mm, addr, ptep, pte);
+}
+#endif /* __HAVE_ARCH_PTEP_MODIFY_PROT_TRANSACTION */
+
 /*
  * 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