[dpdk-dev] [PATCH v3] net/mlx5: fix link status query

[Shahaf Shuler]

Trying to query the link status through the new ETHTOOL_GLINKSETTINGS
ioctl available since Linux 4.5 was always failing due to a kernel bug
fixed since version 4.9.

This commit also addresses a common issue where the headers version used
at compile time differs from that of the kernel on the target system, by
always defining missing symbols and moving the kernel version check at run
time.

Fixes: 188408719888 ("net/mlx5: fix support for newer link speeds")
CC: stable at dpdk.org

Signed-off-by: Shahaf Shuler <shahafs at mellanox.com>
Acked-by: Adrien Mazarguil <adrien.mazarguil at 6wind.com>
---
on v3:
 * Dynamic decision on the link_update function according to the running kernel.

on v2:
 * remove HAVE_ETHTOOL_LINK_MODE_*
---
 drivers/net/mlx5/mlx5_ethdev.c | 84 +++++++++++++++++++++++++++++++-----------
 1 file changed, 63 insertions(+), 21 deletions(-)

diff --git a/drivers/net/mlx5/mlx5_ethdev.c b/drivers/net/mlx5/mlx5_ethdev.c
index 8efdff7..40336ad 100644
--- a/drivers/net/mlx5/mlx5_ethdev.c
+++ b/drivers/net/mlx5/mlx5_ethdev.c
@@ -43,9 +43,11 @@
 #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>
 
 /* DPDK headers don't like -pedantic. */
@@ -67,6 +69,57 @@
 #include "mlx5_rxtx.h"
 #include "mlx5_utils.h"
 
+/* Add defines in case the running kernel is not the same as user headers. */
+#ifndef ETHTOOL_GLINKSETTINGS
+struct ethtool_link_settings {
+	uint32_t cmd;
+	uint32_t speed;
+	uint8_t duplex;
+	uint8_t port;
+	uint8_t phy_address;
+	uint8_t autoneg;
+	uint8_t mdio_support;
+	uint8_t eth_to_mdix;
+	uint8_t eth_tp_mdix_ctrl;
+	int8_t link_mode_masks_nwords;
+	uint32_t reserved[8];
+	uint32_t link_mode_masks[];
+};
+
+#define ETHTOOL_GLINKSETTINGS 0x0000004c
+#define ETHTOOL_LINK_MODE_1000baseT_Full_BIT 5
+#define ETHTOOL_LINK_MODE_Autoneg_BIT 6
+#define ETHTOOL_LINK_MODE_1000baseKX_Full_BIT 17
+#define ETHTOOL_LINK_MODE_10000baseKX4_Full_BIT 18
+#define ETHTOOL_LINK_MODE_10000baseKR_Full_BIT 19
+#define ETHTOOL_LINK_MODE_10000baseR_FEC_BIT 20
+#define ETHTOOL_LINK_MODE_20000baseMLD2_Full_BIT 21
+#define ETHTOOL_LINK_MODE_20000baseKR2_Full_BIT 22
+#define ETHTOOL_LINK_MODE_40000baseKR4_Full_BIT 23
+#define ETHTOOL_LINK_MODE_40000baseCR4_Full_BIT 24
+#define ETHTOOL_LINK_MODE_40000baseSR4_Full_BIT 25
+#define ETHTOOL_LINK_MODE_40000baseLR4_Full_BIT 26
+#define ETHTOOL_LINK_MODE_56000baseKR4_Full_BIT 27
+#define ETHTOOL_LINK_MODE_56000baseCR4_Full_BIT 28
+#define ETHTOOL_LINK_MODE_56000baseSR4_Full_BIT 29
+#define ETHTOOL_LINK_MODE_56000baseLR4_Full_BIT 30
+#endif
+#ifndef HAVE_ETHTOOL_LINK_MODE_25G
+#define ETHTOOL_LINK_MODE_25000baseCR_Full_BIT 31
+#define ETHTOOL_LINK_MODE_25000baseKR_Full_BIT 32
+#define ETHTOOL_LINK_MODE_25000baseSR_Full_BIT 33
+#endif
+#ifndef HAVE_ETHTOOL_LINK_MODE_50G
+#define ETHTOOL_LINK_MODE_50000baseCR2_Full_BIT 34
+#define ETHTOOL_LINK_MODE_50000baseKR2_Full_BIT 35
+#endif
+#ifndef HAVE_ETHTOOL_LINK_MODE_100G
+#define ETHTOOL_LINK_MODE_100000baseKR4_Full_BIT 36
+#define ETHTOOL_LINK_MODE_100000baseSR4_Full_BIT 37
+#define ETHTOOL_LINK_MODE_100000baseCR4_Full_BIT 38
+#define ETHTOOL_LINK_MODE_100000baseLR4_ER4_Full_BIT 39
+#endif
+
 /**
  * Return private structure associated with an Ethernet device.
  *
@@ -696,8 +749,7 @@ struct priv *
 }
 
 /**
- * Retrieve physical link information (unlocked version using new ioctl from
- * Linux 4.5).
+ * Retrieve physical link information (unlocked version using new ioctl).
  *
  * @param dev
  *   Pointer to Ethernet device structure.
@@ -707,7 +759,6 @@ struct priv *
 static int
 mlx5_link_update_unlocked_gs(struct rte_eth_dev *dev, int wait_to_complete)
 {
-#ifdef ETHTOOL_GLINKSETTINGS
 	struct priv *priv = mlx5_get_priv(dev);
 	struct ethtool_link_settings edata = {
 		.cmd = ETHTOOL_GLINKSETTINGS,
@@ -734,7 +785,6 @@ struct priv *
 	sc = edata.link_mode_masks[0] |
 		((uint64_t)edata.link_mode_masks[1] << 32);
 	priv->link_speed_capa = 0;
-	/* Link speeds available in kernel v4.5. */
 	if (sc & ETHTOOL_LINK_MODE_Autoneg_BIT)
 		priv->link_speed_capa |= ETH_LINK_SPEED_AUTONEG;
 	if (sc & (ETHTOOL_LINK_MODE_1000baseT_Full_BIT |
@@ -757,25 +807,18 @@ struct priv *
 		  ETHTOOL_LINK_MODE_56000baseSR4_Full_BIT |
 		  ETHTOOL_LINK_MODE_56000baseLR4_Full_BIT))
 		priv->link_speed_capa |= ETH_LINK_SPEED_56G;
-	/* Link speeds available in kernel v4.6. */
-#ifdef HAVE_ETHTOOL_LINK_MODE_25G
 	if (sc & (ETHTOOL_LINK_MODE_25000baseCR_Full_BIT |
 		  ETHTOOL_LINK_MODE_25000baseKR_Full_BIT |
 		  ETHTOOL_LINK_MODE_25000baseSR_Full_BIT))
 		priv->link_speed_capa |= ETH_LINK_SPEED_25G;
-#endif
-#ifdef HAVE_ETHTOOL_LINK_MODE_50G
 	if (sc & (ETHTOOL_LINK_MODE_50000baseCR2_Full_BIT |
 		  ETHTOOL_LINK_MODE_50000baseKR2_Full_BIT))
 		priv->link_speed_capa |= ETH_LINK_SPEED_50G;
-#endif
-#ifdef HAVE_ETHTOOL_LINK_MODE_100G
 	if (sc & (ETHTOOL_LINK_MODE_100000baseKR4_Full_BIT |
 		  ETHTOOL_LINK_MODE_100000baseSR4_Full_BIT |
 		  ETHTOOL_LINK_MODE_100000baseCR4_Full_BIT |
 		  ETHTOOL_LINK_MODE_100000baseLR4_ER4_Full_BIT))
 		priv->link_speed_capa |= ETH_LINK_SPEED_100G;
-#endif
 	dev_link.link_duplex = ((edata.duplex == DUPLEX_HALF) ?
 				ETH_LINK_HALF_DUPLEX : ETH_LINK_FULL_DUPLEX);
 	dev_link.link_autoneg = !(dev->data->dev_conf.link_speeds &
@@ -785,10 +828,6 @@ struct priv *
 		dev->data->dev_link = dev_link;
 		return 0;
 	}
-#else
-	(void)dev;
-	(void)wait_to_complete;
-#endif
 	/* Link status is still the same. */
 	return -1;
 }
@@ -804,12 +843,15 @@ struct priv *
 int
 mlx5_link_update(struct rte_eth_dev *dev, int wait_to_complete)
 {
-	int ret;
-
-	ret = mlx5_link_update_unlocked_gs(dev, wait_to_complete);
-	if (ret < 0)
-		ret = mlx5_link_update_unlocked_gset(dev, wait_to_complete);
-	return ret;
+	struct utsname utsname;
+	int ver[3];
+
+	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))
+		return mlx5_link_update_unlocked_gset(dev, wait_to_complete);
+	return mlx5_link_update_unlocked_gs(dev, wait_to_complete);
 }
 
 /**
-- 
1.8.3.1