From 427c896f262ad70d1e6b04890945675df13bb031 Mon Sep 17 00:00:00 2001
From: Matthew Wilcox <mawilcox@microsoft.com>
Date: Tue, 10 Apr 2018 16:36:36 -0700
Subject: arm64: turn flush_dcache_mmap_lock into a no-op
ARM64 doesn't walk the VMA tree in its flush_dcache_page()
implementation, so has no need to take the tree_lock.
Link: http://lkml.kernel.org/r/20180313132639.17387-4-willy@infradead.org
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Cc: Darrick J. Wong <darrick.wong@oracle.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jeff Layton <jlayton@kernel.org>
Cc: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
arch/arm64/include/asm/cacheflush.h | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)
diff --git a/arch/arm64/include/asm/cacheflush.h b/arch/arm64/include/asm/cacheflush.h
index 7dfcec4700fe..0094c6653b06 100644
--- a/arch/arm64/include/asm/cacheflush.h
+++ b/arch/arm64/include/asm/cacheflush.h
@@ -140,10 +140,8 @@ static inline void __flush_icache_all(void)
dsb(ish);
}
-#define flush_dcache_mmap_lock(mapping) \
- spin_lock_irq(&(mapping)->tree_lock)
-#define flush_dcache_mmap_unlock(mapping) \
- spin_unlock_irq(&(mapping)->tree_lock)
+#define flush_dcache_mmap_lock(mapping) do { } while (0)
+#define flush_dcache_mmap_unlock(mapping) do { } while (0)
/*
* We don't appear to need to do anything here. In fact, if we did, we'd
--
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