[dpdk-dev] [PATCH] Add support for Tx->Rx loopback mode for 82599.

[Qinglai Xiao]

82599 has two loopback operation modes, Tx->Rx and Rx->Tx.
For the time being only Tx->Rx is supported.

The new field lpbk_mode added in struct rte_eth_conf defines loopback
operation mode for certain ethernet controller. By default the value
of lpbk_mode is 0, meaning loopback mode disabled.

Since each ethernet controller has its own definition of loopback modes,
API user has to check both datasheet and implementation of certain driver
so as to understand what are valid values to be set, and what are the
expected behaviors.

Check IXGBE_LPBK_82599_XXX which are defined in ixgbe_ethdev.h
for valid values of 82599 loopback mode.

Signed-off-by: Qinglai Xiao <jigsaw at gmail.com>
---
 lib/librte_ether/rte_ethdev.h       |    5 +++++
 lib/librte_pmd_ixgbe/ixgbe_ethdev.c |    7 ++++++
 lib/librte_pmd_ixgbe/ixgbe_ethdev.h |    5 +++++
 lib/librte_pmd_ixgbe/ixgbe_rxtx.c   |   42 +++++++++++++++++++++++++++++++++++
 4 files changed, 59 insertions(+)

diff --git a/lib/librte_ether/rte_ethdev.h b/lib/librte_ether/rte_ethdev.h
index 2d7385f..4c1b3c8 100644
--- a/lib/librte_ether/rte_ethdev.h
+++ b/lib/librte_ether/rte_ethdev.h
@@ -672,6 +672,11 @@ struct rte_eth_conf {
 	/**< ETH_LINK_[HALF_DUPLEX|FULL_DUPLEX], or 0 for autonegotation */
 	struct rte_eth_rxmode rxmode; /**< Port RX configuration. */
 	struct rte_eth_txmode txmode; /**< Port TX configuration. */
+	uint32_t lpbk_mode; /**< Loopback operation mode. By default the value
+			         is 0, meaning the loopback mode is disabled.
+				 Read the datasheet of given ethernet controller
+				 for details. The possible values of this field
+				 are defined in implementation of each driver. */
 	union {
 		struct rte_eth_rss_conf rss_conf; /**< Port RSS configuration */
 		struct rte_eth_vmdq_dcb_conf vmdq_dcb_conf;
diff --git a/lib/librte_pmd_ixgbe/ixgbe_ethdev.c b/lib/librte_pmd_ixgbe/ixgbe_ethdev.c
index 9235f9d..efb8a3b 100644
--- a/lib/librte_pmd_ixgbe/ixgbe_ethdev.c
+++ b/lib/librte_pmd_ixgbe/ixgbe_ethdev.c
@@ -1203,6 +1203,11 @@ ixgbe_dev_start(struct rte_eth_dev *dev)
 	/* Turn on the laser */
 	ixgbe_enable_tx_laser(hw);
 
+	/* Skip link setup if loopback mode is enabled for 82599. */
+	if (hw->mac.type == ixgbe_mac_82599EB &&
+			dev->data->dev_conf.lpbk_mode == IXGBE_LPBK_82599_TX_RX)
+		goto skip_link_setup;
+
 	err = ixgbe_check_link(hw, &speed, &link_up, 0);
 	if (err)
 		goto error;
@@ -1239,6 +1244,8 @@ ixgbe_dev_start(struct rte_eth_dev *dev)
 	if (err)
 		goto error;
 
+skip_link_setup:
+
 	/* check if lsc interrupt is enabled */
 	if (dev->data->dev_conf.intr_conf.lsc != 0)
 		ixgbe_dev_lsc_interrupt_setup(dev);
diff --git a/lib/librte_pmd_ixgbe/ixgbe_ethdev.h b/lib/librte_pmd_ixgbe/ixgbe_ethdev.h
index 260622a..4884841 100644
--- a/lib/librte_pmd_ixgbe/ixgbe_ethdev.h
+++ b/lib/librte_pmd_ixgbe/ixgbe_ethdev.h
@@ -62,6 +62,11 @@
 #endif
 #define IXGBE_HWSTRIP_BITMAP_SIZE (IXGBE_MAX_RX_QUEUE_NUM / (sizeof(uint32_t) * NBBY))
 
+/* 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. */
+
 
 /*
  * Information about the fdir mode.
diff --git a/lib/librte_pmd_ixgbe/ixgbe_rxtx.c b/lib/librte_pmd_ixgbe/ixgbe_rxtx.c
index 5fba01d..5c8668e 100644
--- a/lib/librte_pmd_ixgbe/ixgbe_rxtx.c
+++ b/lib/librte_pmd_ixgbe/ixgbe_rxtx.c
@@ -78,6 +78,7 @@
 #include "ixgbe/ixgbe_vf.h"
 #include "ixgbe_ethdev.h"
 #include "ixgbe/ixgbe_dcb.h"
+#include "ixgbe/ixgbe_common.h"
 
 
 #define RTE_PMD_IXGBE_TX_MAX_BURST 32
@@ -3252,6 +3253,13 @@ ixgbe_dev_rx_init(struct rte_eth_dev *dev)
 	} else
 		hlreg0 &= ~IXGBE_HLREG0_JUMBOEN;
 
+	/*
+	 * If loopback mode is configured for 82599, set LPBK bit.
+	 */
+	if (hw->mac.type == ixgbe_mac_82599EB &&
+			dev->data->dev_conf.lpbk_mode == IXGBE_LPBK_82599_TX_RX)
+		hlreg0 |= IXGBE_HLREG0_LPBK;
+
 	IXGBE_WRITE_REG(hw, IXGBE_HLREG0, hlreg0);
 
 	/* Setup RX queues */
@@ -3432,6 +3440,34 @@ ixgbe_dev_tx_init(struct rte_eth_dev *dev)
 }
 
 /*
+ * Set up link for 82599 loopback mode Tx->Rx.
+ */
+static inline void
+ixgbe_setup_loopback_link_82599(struct ixgbe_hw *hw)
+{
+	DEBUGFUNC("ixgbe_setup_loopback_link_82599");
+
+	if (ixgbe_verify_lesm_fw_enabled_82599(hw)) {
+		if (hw->mac.ops.acquire_swfw_sync(hw, IXGBE_GSSR_MAC_CSR_SM) !=
+				IXGBE_SUCCESS) {
+			PMD_INIT_LOG(ERR, "Could not enable loopback mode\n");
+			/* ignore error */
+			return;
+		}
+	}
+
+	/* Restart link */
+	IXGBE_WRITE_REG(hw,
+			IXGBE_AUTOC,
+			IXGBE_AUTOC_LMS_10G_LINK_NO_AN | IXGBE_AUTOC_FLU);
+	ixgbe_reset_pipeline_82599(hw);
+
+	hw->mac.ops.release_swfw_sync(hw, IXGBE_GSSR_MAC_CSR_SM);
+	msec_delay(50);
+}
+
+
+/*
  * Start Transmit and Receive Units.
  */
 void
@@ -3509,6 +3545,12 @@ ixgbe_dev_rxtx_start(struct rte_eth_dev *dev)
 		rxctrl |= IXGBE_RXCTRL_DMBYPS;
 	rxctrl |= IXGBE_RXCTRL_RXEN;
 	hw->mac.ops.enable_rx_dma(hw, rxctrl);
+
+	/* If loopback mode is enabled for 82599, set up the link accordingly */
+	if (hw->mac.type == ixgbe_mac_82599EB &&
+			dev->data->dev_conf.lpbk_mode == IXGBE_LPBK_82599_TX_RX)
+		ixgbe_setup_loopback_link_82599(hw);
+
 }
 
 
-- 
1.7.9.5