From 17a1f07e5795b31d1a5bd5461b55e75015fceae9 Mon Sep 17 00:00:00 2001
From: Dariusz Stojaczyk <dariuszx.stojaczyk@intel.com>
Date: Thu, 23 Nov 2017 14:40:39 +0100
Subject: [PATCH] rte_virtio: removed direct rte_smb_*mb calls

Replaced them with spdk alternatives.
While here, also clarified the documentation
for virtio_*mb.

Change-Id: Ia604e9abd8eadc18fa3ea1a782e29e7da6b3c162
Signed-off-by: Dariusz Stojaczyk <dariuszx.stojaczyk@intel.com>
Reviewed-on: https://review.gerrithub.io/385627
Reviewed-by: Jim Harris <james.r.harris@intel.com>
Reviewed-by: Daniel Verkamp <daniel.verkamp@intel.com>
Reviewed-by: Ben Walker <benjamin.walker@intel.com>
Tested-by: SPDK Automated Test System <sys_sgsw@intel.com>
---
 lib/bdev/virtio/rte_virtio/virtio.c | 16 ++++++----------
 1 file changed, 6 insertions(+), 10 deletions(-)

diff --git a/lib/bdev/virtio/rte_virtio/virtio.c b/lib/bdev/virtio/rte_virtio/virtio.c
index 126070b93..4acbdbadd 100644
--- a/lib/bdev/virtio/rte_virtio/virtio.c
+++ b/lib/bdev/virtio/rte_virtio/virtio.c
@@ -48,7 +48,6 @@
 #include <rte_common.h>
 #include <rte_errno.h>
 
-#include <rte_memory.h>
 #include <rte_eal.h>
 #include <rte_dev.h>
 #include <rte_prefetch.h>
@@ -56,16 +55,13 @@
 #include "spdk/env.h"
 #include "spdk/barrier.h"
 
-/*
- * Per virtio_config.h in Linux.
- *     For virtio_pci on SMP, we don't need to order with respect to MMIO
- *     accesses through relaxed memory I/O windows, so smp_mb() et al are
- *     sufficient.
- *
+/* We use SMP memory barrier variants as all virtio_pci devices
+ * are purely virtual. All MMIO is executed on a CPU core, so
+ * there's no need to do full MMIO synchronization.
  */
-#define virtio_mb()	rte_smp_mb()
-#define virtio_rmb()	rte_smp_rmb()
-#define virtio_wmb()	rte_smp_wmb()
+#define virtio_mb()	spdk_smp_mb()
+#define virtio_rmb()	spdk_smp_rmb()
+#define virtio_wmb()	spdk_smp_wmb()
 
 #include "virtio.h"