UBUNTU: SAUCE: (noup) arm64, mm, numa: Add NUMA balancing support for arm64.

BugLink: http://bugs.launchpad.net/bugs/1558765

Enable NUMA balancing for arm64 platforms.
Add pte, pmd protnone helpers for use by automatic NUMA balancing.
Reviewed-by: Robert Richter <rrichter@cavium.com>
Signed-off-by: Ganapatrao Kulkarni <gkulkarni@caviumnetworks.com>
Signed-off-by: David Daney <david.daney@cavium.com>
[ dannf: v15 submittal ]
Reference: http://www.spinics.net/lists/arm-kernel/msg489639.htmlSigned-off-by: dann frazier <dann.frazier@canonical.com>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>

arch/arm64/Kconfig

@@ -10,6 +10,7 @@ config ARM64
 	select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
 	select ARCH_USE_CMPXCHG_LOCKREF
 	select ARCH_SUPPORTS_ATOMIC_RMW
+	select ARCH_SUPPORTS_NUMA_BALANCING
 	select ARCH_WANT_OPTIONAL_GPIOLIB
 	select ARCH_WANT_COMPAT_IPC_PARSE_VERSION
 	select ARCH_WANT_FRAME_POINTERS

arch/arm64/include/asm/pgtable.h

@@ -333,6 +333,21 @@ static inline pgprot_t mk_sect_prot(pgprot_t prot)
 	return __pgprot(pgprot_val(prot) & ~PTE_TABLE_BIT);
 }
 
+#ifdef CONFIG_NUMA_BALANCING
+/*
+ * See the comment in include/asm-generic/pgtable.h
+ */
+static inline int pte_protnone(pte_t pte)
+{
+	return (pte_val(pte) & (PTE_VALID | PTE_PROT_NONE)) == PTE_PROT_NONE;
+}
+
+static inline int pmd_protnone(pmd_t pmd)
+{
+	return pte_protnone(pmd_pte(pmd));
+}
+#endif
+
 /*
  * THP definitions.
  */