[PATCH v9 rebase on mm-unstable 2/8] arm64: tlbflush: add APIs manipulating tlb batch's arch data

[Byungchul Park <byungchul@sk.com>]

This is a preparation for migrc mechanism that requires to manipulate
tlb batch's arch data.  Even though arm64 does nothing for it, arch
with CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH should provide the APIs.

Signed-off-by: Byungchul Park <byungchul@sk.com>
---
 arch/arm64/include/asm/tlbflush.h | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/arch/arm64/include/asm/tlbflush.h b/arch/arm64/include/asm/tlbflush.h
index a75de2665d84..b8c7fbc1c68e 100644
--- a/arch/arm64/include/asm/tlbflush.h
+++ b/arch/arm64/include/asm/tlbflush.h
@@ -347,6 +347,24 @@ static inline void arch_tlbbatch_flush(struct arch_tlbflush_unmap_batch *batch)
 	dsb(ish);
 }
 
+static inline void arch_tlbbatch_clear(struct arch_tlbflush_unmap_batch *batch)
+{
+	/* nothing to do */
+}
+
+static inline void arch_tlbbatch_fold(struct arch_tlbflush_unmap_batch *bdst,
+			       struct arch_tlbflush_unmap_batch *bsrc)
+{
+	/* nothing to do */
+}
+
+static inline bool arch_tlbbatch_done(struct arch_tlbflush_unmap_batch *bdst,
+			       struct arch_tlbflush_unmap_batch *bsrc)
+{
+	/* Kernel can consider tlb batch always has been done. */
+	return true;
+}
+
 /*
  * This is meant to avoid soft lock-ups on large TLB flushing ranges and not
  * necessarily a performance improvement.
-- 
2.17.1