[dpdk-dev] [PATCH v3 2/2] net/ixgbe: add support of loopback for X540/X550

[Julien Meunier <julien.meunier@nokia.com>]

Loopback mode is also supported on X540 and X550 NICs, according to
their datasheet (section 15.2). The way to set it up is a little
different of the 82599.

Signed-off-by: Julien Meunier <julien.meunier@nokia.com>
---
v3:
- reorganize and merge common code
- restore MACC_FLU on stop
v2:
- disable / enable autoneg when loopback is requested for X540 / X550
---
 drivers/net/ixgbe/ixgbe_ethdev.h |  7 +++---
 drivers/net/ixgbe/ixgbe_rxtx.c   | 53 ++++++++++++++++++++++++++++++++++++++--
 2 files changed, 55 insertions(+), 5 deletions(-)

diff --git a/drivers/net/ixgbe/ixgbe_ethdev.h b/drivers/net/ixgbe/ixgbe_ethdev.h
index 565c69c..99a5077 100644
--- a/drivers/net/ixgbe/ixgbe_ethdev.h
+++ b/drivers/net/ixgbe/ixgbe_ethdev.h
@@ -65,9 +65,10 @@
 #define IXGBE_QUEUE_ITR_INTERVAL_DEFAULT	500 /* 500us */
 
 /* Loopback operation modes */
-/* 82599 specific loopback operation types */
-#define IXGBE_LPBK_82599_NONE   0x0 /* Default value. Loopback is disabled. */
-#define IXGBE_LPBK_82599_TX_RX  0x1 /* Tx->Rx loopback operation is enabled. */
+#define IXGBE_LPBK_NONE   0x0 /* Default value. Loopback is disabled. */
+#define IXGBE_LPBK_TX_RX  0x1 /* Tx->Rx loopback operation is enabled. */
+/* X540-X550 specific loopback operations */
+#define IXGBE_MII_AUTONEG_ENABLE        0x1000 /* Auto-negociation enable (default = 1) */
 
 #define IXGBE_MAX_JUMBO_FRAME_SIZE      0x2600 /* Maximum Jumbo frame size. */
 
diff --git a/drivers/net/ixgbe/ixgbe_rxtx.c b/drivers/net/ixgbe/ixgbe_rxtx.c
index c9a70a8..e92a70f 100644
--- a/drivers/net/ixgbe/ixgbe_rxtx.c
+++ b/drivers/net/ixgbe/ixgbe_rxtx.c
@@ -3168,12 +3168,44 @@ ixgbe_dev_tx_descriptor_status(void *tx_queue, uint16_t offset)
 	return RTE_ETH_TX_DESC_FULL;
 }
 
+/*
+ * Set up link loopback for X540/X550 mode Tx->Rx.
+ */
+static inline void __attribute__((cold))
+ixgbe_setup_loopback_link_x540_x550(struct ixgbe_hw *hw, bool enable)
+{
+	uint32_t macc;
+	PMD_INIT_FUNC_TRACE();
+
+	u16 autoneg_reg = IXGBE_MII_AUTONEG_REG;
+
+	hw->phy.ops.read_reg(hw, IXGBE_MDIO_AUTO_NEG_CONTROL,
+			     IXGBE_MDIO_AUTO_NEG_DEV_TYPE, &autoneg_reg);
+	macc = IXGBE_READ_REG(hw, IXGBE_MACC);
+
+	if (enable) {
+		/* datasheet 15.2.1: disable AUTONEG (PHY Bit 7.0.C) */
+		autoneg_reg |= IXGBE_MII_AUTONEG_ENABLE;
+		/* datasheet 15.2.1: MACC.FLU = 1 (force link up) */
+		macc |= IXGBE_MACC_FLU;
+	} else {
+		autoneg_reg &= ~IXGBE_MII_AUTONEG_ENABLE;
+		macc &= ~IXGBE_MACC_FLU;
+	}
+
+	hw->phy.ops.write_reg(hw, IXGBE_MDIO_AUTO_NEG_CONTROL,
+			      IXGBE_MDIO_AUTO_NEG_DEV_TYPE, autoneg_reg);
+
+	IXGBE_WRITE_REG(hw, IXGBE_MACC, macc);
+}
+
 void __attribute__((cold))
 ixgbe_dev_clear_queues(struct rte_eth_dev *dev)
 {
 	unsigned i;
 	struct ixgbe_adapter *adapter =
 		(struct ixgbe_adapter *)dev->data->dev_private;
+	struct ixgbe_hw *hw = IXGBE_DEV_PRIVATE_TO_HW(dev->data->dev_private);
 
 	PMD_INIT_FUNC_TRACE();
 
@@ -3194,6 +3226,14 @@ ixgbe_dev_clear_queues(struct rte_eth_dev *dev)
 			ixgbe_reset_rx_queue(adapter, rxq);
 		}
 	}
+	/* If loopback mode was enabled, reconfigure the link accordingly */
+	if (dev->data->dev_conf.lpbk_mode != 0) {
+		if (hw->mac.type == ixgbe_mac_X540 ||
+		     hw->mac.type == ixgbe_mac_X550 ||
+		     hw->mac.type == ixgbe_mac_X550EM_x ||
+		     hw->mac.type == ixgbe_mac_X550EM_a)
+			ixgbe_setup_loopback_link_x540_x550(hw, false);
+	}
 }
 
 void
@@ -5074,8 +5114,12 @@ ixgbe_check_supported_loopback_mode(struct rte_eth_dev *dev)
 {
 	struct ixgbe_hw *hw = IXGBE_DEV_PRIVATE_TO_HW(dev->data->dev_private);
 
-	if (dev->data->dev_conf.lpbk_mode == IXGBE_LPBK_82599_TX_RX)
-		if (hw->mac.type == ixgbe_mac_82599EB)
+	if (dev->data->dev_conf.lpbk_mode == IXGBE_LPBK_TX_RX)
+		if (hw->mac.type == ixgbe_mac_82599EB ||
+		     hw->mac.type == ixgbe_mac_X540 ||
+		     hw->mac.type == ixgbe_mac_X550 ||
+		     hw->mac.type == ixgbe_mac_X550EM_x ||
+		     hw->mac.type == ixgbe_mac_X550EM_a)
 			return 0;
 
 	return -ENOTSUP;
@@ -5172,6 +5216,11 @@ ixgbe_dev_rxtx_start(struct rte_eth_dev *dev)
 	if (dev->data->dev_conf.lpbk_mode != 0) {
 		if (hw->mac.type == ixgbe_mac_82599EB)
 			ixgbe_setup_loopback_link_82599(hw);
+		else if (hw->mac.type == ixgbe_mac_X540 ||
+		     hw->mac.type == ixgbe_mac_X550 ||
+		     hw->mac.type == ixgbe_mac_X550EM_x ||
+		     hw->mac.type == ixgbe_mac_X550EM_a)
+			ixgbe_setup_loopback_link_x540_x550(hw, true);
 	}
 
 #ifdef RTE_LIBRTE_SECURITY
-- 
2.10.2