[PATCH v15 6/6] arm64, mm, numa: Add NUMA balancing support for arm64.

[David Daney <ddaney.cavm-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>]

From: Ganapatrao Kulkarni <gkulkarni-M3mlKVOIwJVv6pq1l3V1OdBPR1lH4CV8@public.gmane.org>

Enable NUMA balancing for arm64 platforms.
Add pte, pmd protnone helpers for use by automatic NUMA balancing.

Reviewed-by: Robert Richter <rrichter-YGCgFSpz5w/QT0dZR+AlfA@public.gmane.org>
Signed-off-by: Ganapatrao Kulkarni <gkulkarni-M3mlKVOIwJVv6pq1l3V1OdBPR1lH4CV8@public.gmane.org>
Signed-off-by: David Daney <david.daney-YGCgFSpz5w/QT0dZR+AlfA@public.gmane.org>
---
 arch/arm64/Kconfig               |  1 +
 arch/arm64/include/asm/pgtable.h | 15 +++++++++++++++
 2 files changed, 16 insertions(+)

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 7013087..20f5192 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -11,6 +11,7 @@ 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
diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index 819aff5..2150cb7 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -348,6 +348,21 @@ 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.
  */
-- 
1.8.3.1