From dd3fc8bde15ee6e8b6c7c284cc54e40cd51230e2 Mon Sep 17 00:00:00 2001
From: Daniel Borkmann <daniel@iogearbox.net>
Date: Fri, 12 Apr 2019 00:42:07 +0200
Subject: [PATCH] sync: latest tooling changes from kernel

[ upstream commit 6b7a21140fca461c6d8d5c65a3746e7da50a409e ]

Needed a custom backport. I've changed fallbacks so that we can
partially pull in barriers step by step. I've fixed x86 ones and
added corresponding arm64 barriers.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
---
 include/linux/compiler.h | 58 ++++++++++++++++++++++++++--------------
 1 file changed, 38 insertions(+), 20 deletions(-)

diff --git a/include/linux/compiler.h b/include/linux/compiler.h
index ba96a2e..26336dc 100644
--- a/include/linux/compiler.h
+++ b/include/linux/compiler.h
@@ -13,8 +13,9 @@
 
 #if defined(__x86_64__)
 
-# define smp_rmb()		asm volatile("lfence" ::: "memory")
-# define smp_wmb()		asm volatile("sfence" ::: "memory")
+# define smp_rmb()		barrier()
+# define smp_wmb()		barrier()
+# define smp_mb()		asm volatile("lock; addl $0,-132(%%rsp)" ::: "memory", "cc")
 
 # define smp_store_release(p, v)		\
 do {						\
@@ -29,24 +30,41 @@ do {						\
 	___p;					\
 })
 
-#else
+#elif defined(__aarch64__)
 
-# define smp_mb()		__sync_synchronize()
-# define smp_rmb()		smp_mb()
-# define smp_wmb()		smp_mb()
+# define smp_rmb()		asm volatile("dmb ishld" ::: "memory")
+# define smp_wmb()		asm volatile("dmb ishst" ::: "memory")
+# define smp_mb()		asm volatile("dmb ish" ::: "memory")
 
-# define smp_store_release(p, v)		\
-do {						\
-	smp_mb();				\
-	WRITE_ONCE(*p, v);			\
-} while (0)
-
-# define smp_load_acquire(p)			\
-({						\
-	typeof(*p) ___p = READ_ONCE(*p);	\
-	smp_mb();				\
-	___p;					\
-})
-
-#endif /* defined(__x86_64__) */
 #endif
+
+#ifndef smp_mb
+# define smp_mb()		__sync_synchronize()
+#endif
+
+#ifndef smp_rmb
+# define smp_rmb()		smp_mb()
+#endif
+
+#ifndef smp_wmb
+# define smp_wmb()		smp_mb()
+#endif
+
+#ifndef smp_store_release
+# define smp_store_release(p, v)		\
+do {						\
+	smp_mb();				\
+	WRITE_ONCE(*p, v);			\
+} while (0)
+#endif
+
+#ifndef smp_load_acquire
+# define smp_load_acquire(p)			\
+({						\
+	typeof(*p) ___p = READ_ONCE(*p);	\
+	smp_mb();				\
+	___p;					\
+})
+#endif
+
+#endif /* __LINUX_COMPILER_H */