[dpdk-dev] [v2] net/e1000: i219 unit hang issue fix on reset/close

[Xiao Zhang]

Unit hang may occur if multiple descriptors are available in the rings
during reset or close. This state can be detected by configure status
by bit 8 in register. If the bit is set and there are pending descriptors
in one of the rings, we must flush them before reset or close.

Signed-off-by: Xiao Zhang <xiao.zhang at intel.com>
---
 drivers/net/e1000/base/e1000_ich8lan.h |  1 +
 drivers/net/e1000/e1000_ethdev.h       |  1 +
 drivers/net/e1000/igb_ethdev.c         |  4 ++
 drivers/net/e1000/igb_rxtx.c           | 96 ++++++++++++++++++++++++++++++++++
 4 files changed, 102 insertions(+)

diff --git a/drivers/net/e1000/base/e1000_ich8lan.h b/drivers/net/e1000/base/e1000_ich8lan.h
index bc4ed1d..1f2a3f8 100644
--- a/drivers/net/e1000/base/e1000_ich8lan.h
+++ b/drivers/net/e1000/base/e1000_ich8lan.h
@@ -120,6 +120,7 @@ POSSIBILITY OF SUCH DAMAGE.
 #define E1000_FEXTNVM7_SIDE_CLK_UNGATE	0x00000004
 #if !defined(EXTERNAL_RELEASE) || defined(ULP_SUPPORT)
 #define E1000_FEXTNVM7_DISABLE_SMB_PERST	0x00000020
+#define E1000_FEXTNVM7_NEED_DESCRING_FLUSH	0x00000100
 #endif /* !EXTERNAL_RELEASE || ULP_SUPPORT */
 #define E1000_FEXTNVM9_IOSFSB_CLKGATE_DIS	0x00000800
 #define E1000_FEXTNVM9_IOSFSB_CLKREQ_DIS	0x00001000
diff --git a/drivers/net/e1000/e1000_ethdev.h b/drivers/net/e1000/e1000_ethdev.h
index 67acb73..3451979 100644
--- a/drivers/net/e1000/e1000_ethdev.h
+++ b/drivers/net/e1000/e1000_ethdev.h
@@ -522,5 +522,6 @@ int igb_action_rss_same(const struct rte_flow_action_rss *comp,
 int igb_config_rss_filter(struct rte_eth_dev *dev,
 			struct igb_rte_flow_rss_conf *conf,
 			bool add);
+void igb_flush_desc_rings(struct rte_eth_dev *dev);
 
 #endif /* _E1000_ETHDEV_H_ */
diff --git a/drivers/net/e1000/igb_ethdev.c b/drivers/net/e1000/igb_ethdev.c
index 3ee28cf..845101b 100644
--- a/drivers/net/e1000/igb_ethdev.c
+++ b/drivers/net/e1000/igb_ethdev.c
@@ -1589,6 +1589,10 @@ eth_igb_close(struct rte_eth_dev *dev)
 	eth_igb_stop(dev);
 	adapter->stopped = 1;
 
+	/* Flush desc rings for i219 */
+	if (hw->mac.type >= e1000_pch_spt)
+		igb_flush_desc_rings(dev);
+
 	e1000_phy_hw_reset(hw);
 	igb_release_manageability(hw);
 	igb_hw_control_release(hw);
diff --git a/drivers/net/e1000/igb_rxtx.c b/drivers/net/e1000/igb_rxtx.c
index c5606de..33eeb4e 100644
--- a/drivers/net/e1000/igb_rxtx.c
+++ b/drivers/net/e1000/igb_rxtx.c
@@ -18,6 +18,7 @@
 #include <rte_log.h>
 #include <rte_debug.h>
 #include <rte_pci.h>
+#include <rte_bus_pci.h>
 #include <rte_memory.h>
 #include <rte_memcpy.h>
 #include <rte_memzone.h>
@@ -63,6 +64,9 @@
 #define IGB_TX_OFFLOAD_NOTSUP_MASK \
 		(PKT_TX_OFFLOAD_MASK ^ IGB_TX_OFFLOAD_MASK)
 
+/* PCI offset for querying descriptor ring status*/
+#define PCICFG_DESC_RING_STATUS           0xE4
+
 /**
  * Structure associated with each descriptor of the RX ring of a RX queue.
  */
@@ -2962,3 +2966,95 @@ igb_config_rss_filter(struct rte_eth_dev *dev,
 
 	return 0;
 }
+
+static void e1000_flush_tx_ring(struct rte_eth_dev *dev)
+{
+	struct e1000_hw *hw = E1000_DEV_PRIVATE_TO_HW(dev->data->dev_private);
+	volatile union e1000_adv_tx_desc *tx_desc;
+	uint32_t tdt, tctl, txd_lower = E1000_TXD_CMD_IFCS;
+	uint16_t size = 512;
+	struct igb_tx_queue *txq;
+
+	if (dev->data->tx_queues == NULL)
+		return;
+	txq = dev->data->tx_queues[0];
+
+	tctl = E1000_READ_REG(hw, E1000_TCTL);
+	E1000_WRITE_REG(hw, E1000_TCTL, tctl | E1000_TCTL_EN);
+	tdt = E1000_READ_REG(hw, E1000_TDT(0));
+	if (tdt != txq->tx_tail)
+		return;
+	tx_desc = txq->tx_ring;
+	tx_desc->read.buffer_addr = txq->tx_ring_phys_addr;
+	tx_desc->read.cmd_type_len = rte_cpu_to_le_32(txd_lower | size);
+	tx_desc->read.olinfo_status = 0;
+
+	rte_wmb();
+	txq->tx_tail++;
+	if (txq->tx_tail == txq->nb_tx_desc)
+		txq->tx_tail = 0;
+	rte_io_wmb();
+	E1000_WRITE_REG(hw, E1000_TDT(0), txq->tx_tail);
+	usec_delay(250);
+}
+
+static void e1000_flush_rx_ring(struct rte_eth_dev *dev)
+{
+	uint32_t rctl, rxdctl;
+	struct e1000_hw *hw = E1000_DEV_PRIVATE_TO_HW(dev->data->dev_private);
+
+	rctl = E1000_READ_REG(hw, E1000_RCTL);
+	E1000_WRITE_REG(hw, E1000_TCTL, rctl & ~E1000_RCTL_EN);
+	E1000_WRITE_FLUSH(hw);
+	usec_delay(150);
+
+	rxdctl = E1000_READ_REG(hw, E1000_RXDCTL(0));
+	/* zero the lower 14 bits (prefetch and host thresholds) */
+	rxdctl &= 0xffffc000;
+
+	/* update thresholds: prefetch threshold to 31, host threshold to 1
+	 * and make sure the granularity is "descriptors" and not "cache lines"
+	 */
+	rxdctl |= (0x1F | (1UL << 8) | E1000_RXDCTL_THRESH_UNIT_DESC);
+
+	E1000_WRITE_REG(hw, E1000_RXDCTL(0), rxdctl);
+	/* momentarily enable the RX ring for the changes to take effect */
+	E1000_WRITE_REG(hw, E1000_RCTL, rctl | E1000_RCTL_EN);
+	E1000_WRITE_FLUSH(hw);
+	usec_delay(150);
+	E1000_WRITE_REG(hw, E1000_RCTL, rctl & ~E1000_RCTL_EN);
+}
+
+/**
+ * igb_flush_desc_rings - remove all descriptors from the descriptor rings
+ *
+ * In i219, the descriptor rings must be emptied before resetting/closing the
+ * HW. Failure to do this will cause the HW to enter a unit hang state which
+ * can only be released by PCI reset on the device
+ *
+ */
+
+void igb_flush_desc_rings(struct rte_eth_dev *dev)
+{
+	uint32_t fextnvm11, tdlen;
+	struct e1000_hw *hw = E1000_DEV_PRIVATE_TO_HW(dev->data->dev_private);
+	struct rte_pci_device *pci_dev = RTE_ETH_DEV_TO_PCI(dev);
+	uint32_t hang_state = 0;
+
+	fextnvm11 = E1000_READ_REG(hw, E1000_FEXTNVM11);
+	E1000_WRITE_REG(hw, E1000_FEXTNVM11,
+			fextnvm11 | E1000_FEXTNVM11_DISABLE_MULR_FIX);
+	tdlen = E1000_READ_REG(hw, E1000_TDLEN(0));
+	rte_pci_read_config(pci_dev, &hang_state, sizeof(hang_state),
+				PCICFG_DESC_RING_STATUS);
+
+	/* do nothing if we're not in faulty state, or if the queue is empty */
+	if ((hang_state & E1000_FEXTNVM7_NEED_DESCRING_FLUSH) && tdlen) {
+		/* flush desc ring */
+		e1000_flush_tx_ring(dev);
+		rte_pci_read_config(pci_dev, &hang_state, sizeof(hang_state),
+					PCICFG_DESC_RING_STATUS);
+		if (hang_state & E1000_FEXTNVM7_NEED_DESCRING_FLUSH)
+			e1000_flush_rx_ring(dev);
+	}
+}
-- 
2.7.4