[PATCH 1/2] net/mlx5: add kernel version function

[Nelio Laranjeiro <nelio.laranjeiro@6wind.com>]

Use a function to retrieve the version of the kernel.

Signed-off-by: Nelio Laranjeiro <nelio.laranjeiro@6wind.com>
---
 drivers/net/mlx5/mlx5_ethdev.c | 13 +++++--------
 drivers/net/mlx5/mlx5_utils.h  | 26 ++++++++++++++++++++++++++
 2 files changed, 31 insertions(+), 8 deletions(-)

diff --git a/drivers/net/mlx5/mlx5_ethdev.c b/drivers/net/mlx5/mlx5_ethdev.c
index b73cb53df..0ce9f438a 100644
--- a/drivers/net/mlx5/mlx5_ethdev.c
+++ b/drivers/net/mlx5/mlx5_ethdev.c
@@ -18,11 +18,9 @@
 #include <net/if.h>
 #include <sys/ioctl.h>
 #include <sys/socket.h>
-#include <sys/utsname.h>
 #include <netinet/in.h>
 #include <linux/ethtool.h>
 #include <linux/sockios.h>
-#include <linux/version.h>
 #include <fcntl.h>
 #include <stdalign.h>
 #include <sys/un.h>
@@ -715,15 +713,14 @@ int
 priv_link_update(struct priv *priv, int wait_to_complete)
 {
 	struct rte_eth_dev *dev = priv->dev;
-	struct utsname utsname;
-	int ver[3];
 	int ret;
 	struct rte_eth_link dev_link = dev->data->dev_link;
+	unsigned int current_version = mlx5_kernel_version();
+	int use_new_api = current_version > 0 ?
+		current_version >= KERNEL_VERSION(4, 9, 0) :
+		0;
 
-	if (uname(&utsname) == -1 ||
-	    sscanf(utsname.release, "%d.%d.%d",
-		   &ver[0], &ver[1], &ver[2]) != 3 ||
-	    KERNEL_VERSION(ver[0], ver[1], ver[2]) < KERNEL_VERSION(4, 9, 0))
+	if (use_new_api)
 		ret = mlx5_link_update_unlocked_gset(dev, wait_to_complete);
 	else
 		ret = mlx5_link_update_unlocked_gs(dev, wait_to_complete);
diff --git a/drivers/net/mlx5/mlx5_utils.h b/drivers/net/mlx5/mlx5_utils.h
index e1bfb9cd9..bd179ed21 100644
--- a/drivers/net/mlx5/mlx5_utils.h
+++ b/drivers/net/mlx5/mlx5_utils.h
@@ -12,6 +12,8 @@
 #include <limits.h>
 #include <assert.h>
 #include <errno.h>
+#include <sys/utsname.h>
+#include <linux/version.h>
 
 #include "mlx5_defs.h"
 
@@ -159,4 +161,28 @@ log2above(unsigned int v)
 	return l + r;
 }
 
+/**
+ * retrieve the current kernel version.
+ *
+ * @return
+ *   the current kernel version or negative errno on error.
+ */
+static inline unsigned int
+mlx5_kernel_version(void)
+{
+	struct utsname utsname;
+	int ver[3];
+	int ret;
+
+	ret = uname(&utsname);
+	if (ret == -1)
+		goto error;
+	ret = sscanf(utsname.release, "%d.%d.%d", &ver[0], &ver[1], &ver[2]);
+	if (ret != 3)
+		goto error;
+	return KERNEL_VERSION(ver[0], ver[1], ver[2]);
+error:
+	return -errno;
+}
+
 #endif /* RTE_PMD_MLX5_UTILS_H_ */
-- 
2.11.0