From 2256f5fb4bc353c7d8f4a8c073b27a9677661a57 Mon Sep 17 00:00:00 2001
From: Alexander Boettcher <alexander.boettcher@genode-labs.com>
Date: Fri, 10 Jan 2020 14:08:58 +0100
Subject: [PATCH] dde_linux: add dma_wmb/rmb barriers for arm_v6

---
 .../src/include/spec/arm_v6/lx_emul/barrier.h | 21 +++++++++++--------
 1 file changed, 12 insertions(+), 9 deletions(-)

diff --git a/repos/dde_linux/src/include/spec/arm_v6/lx_emul/barrier.h b/repos/dde_linux/src/include/spec/arm_v6/lx_emul/barrier.h
index a754f14d5..98ccb25d8 100644
--- a/repos/dde_linux/src/include/spec/arm_v6/lx_emul/barrier.h
+++ b/repos/dde_linux/src/include/spec/arm_v6/lx_emul/barrier.h
@@ -11,24 +11,27 @@
  * version 2.
  */
 
-/*******************
- ** asm/barrier.h **
- *******************/
+/*******************************************
+ ** source/arch/arm/include/asm/barrier.h **
+ *******************************************/
 
-#define mb()  asm volatile ("": : :"memory")
+#define dsb() asm volatile ("mcr p15, 0, %0, c7, c10, 4": : "r" (0) : "memory")
+#define dmb() asm volatile ("mcr p15, 0, %0, c7, c10, 5": : "r" (0) : "memory")
+
+#define mb()  dsb()
 #define rmb() mb()
-#define wmb() asm volatile ("": : :"memory")
+#define wmb() dsb()
 
-#define dma_wmb() barrier()
-#define dma_rmb() barrier()
+#define dma_wmb() dmb()
+#define dma_rmb() dmb()
 
 /*
  * This is the "safe" implementation as needed for a configuration
  * with SMP enabled.
  */
 
-#define smp_mb()  asm volatile ("": : :"memory")
+#define smp_mb()  dmb()
 #define smp_rmb() smp_mb()
-#define smp_wmb() asm volatile ("": : :"memory")
+#define smp_wmb() dmb()
 
 static inline void barrier() { asm volatile ("": : :"memory"); }