From e08400b707739f0eca1645413924743466ea70b8 Mon Sep 17 00:00:00 2001 From: Emil Tantilov Date: Wed, 28 Jan 2015 03:21:24 +0000 Subject: [PATCH] ixgbevf: Add code to check for Tx hang This patch adds code to allow for Tx hang checking. The idea is to provide more robust debug info in the event of a transmit unit hang. Similar to the logic in ixgbe. CC: Alexander Duyck Signed-off-by: Emil Tantilov Tested-by: Phil Schmitt Signed-off-by: Jeff Kirsher --- drivers/net/ethernet/intel/ixgbevf/ixgbevf.h | 21 +++- drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c | 113 ++++++++++++++++++---- 2 files changed, 115 insertions(+), 19 deletions(-) diff --git a/drivers/net/ethernet/intel/ixgbevf/ixgbevf.h b/drivers/net/ethernet/intel/ixgbevf/ixgbevf.h index 65cda34..65c2aee 100644 --- a/drivers/net/ethernet/intel/ixgbevf/ixgbevf.h +++ b/drivers/net/ethernet/intel/ixgbevf/ixgbevf.h @@ -43,6 +43,13 @@ #define BP_EXTENDED_STATS #endif +#define IXGBE_MAX_TXD_PWR 14 +#define IXGBE_MAX_DATA_PER_TXD BIT(IXGBE_MAX_TXD_PWR) + +/* Tx Descriptors needed, worst case */ +#define TXD_USE_COUNT(S) DIV_ROUND_UP((S), IXGBE_MAX_DATA_PER_TXD) +#define DESC_NEEDED (MAX_SKB_FRAGS + 4) + /* wrapper around a pointer to a socket buffer, * so a DMA handle can be stored along with the buffer */ struct ixgbevf_tx_buffer { @@ -85,6 +92,18 @@ struct ixgbevf_rx_queue_stats { u64 csum_err; }; +enum ixgbevf_ring_state_t { + __IXGBEVF_TX_DETECT_HANG, + __IXGBEVF_HANG_CHECK_ARMED, +}; + +#define check_for_tx_hang(ring) \ + test_bit(__IXGBEVF_TX_DETECT_HANG, &(ring)->state) +#define set_check_for_tx_hang(ring) \ + set_bit(__IXGBEVF_TX_DETECT_HANG, &(ring)->state) +#define clear_check_for_tx_hang(ring) \ + clear_bit(__IXGBEVF_TX_DETECT_HANG, &(ring)->state) + struct ixgbevf_ring { struct ixgbevf_ring *next; struct net_device *netdev; @@ -101,7 +120,7 @@ struct ixgbevf_ring { struct ixgbevf_tx_buffer *tx_buffer_info; struct ixgbevf_rx_buffer *rx_buffer_info; }; - + unsigned long state; struct ixgbevf_stats stats; struct u64_stats_sync syncp; union { diff --git a/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c b/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c index a4b3d66..87f9f86 100644 --- a/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c +++ b/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c @@ -199,14 +199,64 @@ static void ixgbevf_unmap_and_free_tx_resource(struct ixgbevf_ring *tx_ring, /* tx_buffer must be completely set up in the transmit path */ } -#define IXGBE_MAX_TXD_PWR 14 -#define IXGBE_MAX_DATA_PER_TXD (1 << IXGBE_MAX_TXD_PWR) +static u64 ixgbevf_get_tx_completed(struct ixgbevf_ring *ring) +{ + return ring->stats.packets; +} + +static u32 ixgbevf_get_tx_pending(struct ixgbevf_ring *ring) +{ + struct ixgbevf_adapter *adapter = netdev_priv(ring->netdev); + struct ixgbe_hw *hw = &adapter->hw; + + u32 head = IXGBE_READ_REG(hw, IXGBE_VFTDH(ring->reg_idx)); + u32 tail = IXGBE_READ_REG(hw, IXGBE_VFTDT(ring->reg_idx)); + + if (head != tail) + return (head < tail) ? + tail - head : (tail + ring->count - head); + + return 0; +} + +static inline bool ixgbevf_check_tx_hang(struct ixgbevf_ring *tx_ring) +{ + u32 tx_done = ixgbevf_get_tx_completed(tx_ring); + u32 tx_done_old = tx_ring->tx_stats.tx_done_old; + u32 tx_pending = ixgbevf_get_tx_pending(tx_ring); + + clear_check_for_tx_hang(tx_ring); -/* Tx Descriptors needed, worst case */ -#define TXD_USE_COUNT(S) DIV_ROUND_UP((S), IXGBE_MAX_DATA_PER_TXD) -#define DESC_NEEDED (MAX_SKB_FRAGS + 4) + /* Check for a hung queue, but be thorough. This verifies + * that a transmit has been completed since the previous + * check AND there is at least one packet pending. The + * ARMED bit is set to indicate a potential hang. + */ + if ((tx_done_old == tx_done) && tx_pending) { + /* make sure it is true for two checks in a row */ + return test_and_set_bit(__IXGBEVF_HANG_CHECK_ARMED, + &tx_ring->state); + } + /* reset the countdown */ + clear_bit(__IXGBEVF_HANG_CHECK_ARMED, &tx_ring->state); + + /* update completed stats and continue */ + tx_ring->tx_stats.tx_done_old = tx_done; + + return false; +} + +/** + * ixgbevf_tx_timeout - Respond to a Tx Hang + * @netdev: network interface device structure + **/ +static void ixgbevf_tx_timeout(struct net_device *netdev) +{ + struct ixgbevf_adapter *adapter = netdev_priv(netdev); -static void ixgbevf_tx_timeout(struct net_device *netdev); + /* Do the reset outside of interrupt context */ + schedule_work(&adapter->reset_task); +} /** * ixgbevf_clean_tx_irq - Reclaim resources after transmit completes @@ -311,6 +361,37 @@ static bool ixgbevf_clean_tx_irq(struct ixgbevf_q_vector *q_vector, q_vector->tx.total_bytes += total_bytes; q_vector->tx.total_packets += total_packets; + if (check_for_tx_hang(tx_ring) && ixgbevf_check_tx_hang(tx_ring)) { + struct ixgbe_hw *hw = &adapter->hw; + union ixgbe_adv_tx_desc *eop_desc; + + eop_desc = tx_ring->tx_buffer_info[i].next_to_watch; + + pr_err("Detected Tx Unit Hang\n" + " Tx Queue <%d>\n" + " TDH, TDT <%x>, <%x>\n" + " next_to_use <%x>\n" + " next_to_clean <%x>\n" + "tx_buffer_info[next_to_clean]\n" + " next_to_watch <%p>\n" + " eop_desc->wb.status <%x>\n" + " time_stamp <%lx>\n" + " jiffies <%lx>\n", + tx_ring->queue_index, + IXGBE_READ_REG(hw, IXGBE_VFTDH(tx_ring->reg_idx)), + IXGBE_READ_REG(hw, IXGBE_VFTDT(tx_ring->reg_idx)), + tx_ring->next_to_use, i, + eop_desc, (eop_desc ? eop_desc->wb.status : 0), + tx_ring->tx_buffer_info[i].time_stamp, jiffies); + + netif_stop_subqueue(tx_ring->netdev, tx_ring->queue_index); + + /* schedule immediate reset if we believe we hung */ + schedule_work(&adapter->reset_task); + + return true; + } + #define TX_WAKE_THRESHOLD (DESC_NEEDED * 2) if (unlikely(total_packets && netif_carrier_ok(tx_ring->netdev) && (ixgbevf_desc_unused(tx_ring) >= TX_WAKE_THRESHOLD))) { @@ -1479,6 +1560,8 @@ static void ixgbevf_configure_tx_ring(struct ixgbevf_adapter *adapter, txdctl |= (1 << 8) | /* HTHRESH = 1 */ 32; /* PTHRESH = 32 */ + clear_bit(__IXGBEVF_HANG_CHECK_ARMED, &ring->state); + IXGBE_WRITE_REG(hw, IXGBE_VFTXDCTL(reg_idx), txdctl); /* poll to verify queue is enabled */ @@ -2643,6 +2726,12 @@ static void ixgbevf_watchdog(unsigned long data) if (test_bit(__IXGBEVF_DOWN, &adapter->state)) goto watchdog_short_circuit; + /* Force detection of hung controller */ + if (netif_carrier_ok(adapter->netdev)) { + for (i = 0; i < adapter->num_tx_queues; i++) + set_check_for_tx_hang(adapter->tx_ring[i]); + } + /* get one bit for every active tx/rx interrupt vector */ for (i = 0; i < adapter->num_msix_vectors - NON_Q_VECTORS; i++) { struct ixgbevf_q_vector *qv = adapter->q_vector[i]; @@ -2656,18 +2745,6 @@ watchdog_short_circuit: schedule_work(&adapter->watchdog_task); } -/** - * ixgbevf_tx_timeout - Respond to a Tx Hang - * @netdev: network interface device structure - **/ -static void ixgbevf_tx_timeout(struct net_device *netdev) -{ - struct ixgbevf_adapter *adapter = netdev_priv(netdev); - - /* Do the reset outside of interrupt context */ - schedule_work(&adapter->reset_task); -} - static void ixgbevf_reset_task(struct work_struct *work) { struct ixgbevf_adapter *adapter; -- 2.7.4