From 8510e1a3d16c7e4e2b47c9675b18725407c616b7 Mon Sep 17 00:00:00 2001 From: Netanel Belgazal Date: Thu, 28 Dec 2017 21:31:30 +0000 Subject: [PATCH] net: ena: add detection and recovery mechanism for handling missed/misrouted MSI-X A mechanism for detection of stuck Rx/Tx rings due to missed or misrouted interrupts. Check if there are unhandled completion descriptors before the first MSI-X interrupt arrived. The check is per queue and per interrupt vector. Once such condition is detected, driver and device reset is scheduled. Signed-off-by: Netanel Belgazal Signed-off-by: David S. Miller --- drivers/net/ethernet/amazon/ena/ena_eth_com.c | 11 ++++ drivers/net/ethernet/amazon/ena/ena_eth_com.h | 2 + drivers/net/ethernet/amazon/ena/ena_netdev.c | 68 ++++++++++++++++++++++--- drivers/net/ethernet/amazon/ena/ena_netdev.h | 4 ++ drivers/net/ethernet/amazon/ena/ena_regs_defs.h | 2 + 5 files changed, 80 insertions(+), 7 deletions(-) diff --git a/drivers/net/ethernet/amazon/ena/ena_eth_com.c b/drivers/net/ethernet/amazon/ena/ena_eth_com.c index b11e573ad57a..ea149c134e15 100644 --- a/drivers/net/ethernet/amazon/ena/ena_eth_com.c +++ b/drivers/net/ethernet/amazon/ena/ena_eth_com.c @@ -504,3 +504,14 @@ int ena_com_tx_comp_req_id_get(struct ena_com_io_cq *io_cq, u16 *req_id) return 0; } + +bool ena_com_cq_empty(struct ena_com_io_cq *io_cq) +{ + struct ena_eth_io_rx_cdesc_base *cdesc; + + cdesc = ena_com_get_next_rx_cdesc(io_cq); + if (cdesc) + return false; + else + return true; +} diff --git a/drivers/net/ethernet/amazon/ena/ena_eth_com.h b/drivers/net/ethernet/amazon/ena/ena_eth_com.h index bb53c3a4f8e9..2f7657227cfe 100644 --- a/drivers/net/ethernet/amazon/ena/ena_eth_com.h +++ b/drivers/net/ethernet/amazon/ena/ena_eth_com.h @@ -88,6 +88,8 @@ int ena_com_add_single_rx_desc(struct ena_com_io_sq *io_sq, int ena_com_tx_comp_req_id_get(struct ena_com_io_cq *io_cq, u16 *req_id); +bool ena_com_cq_empty(struct ena_com_io_cq *io_cq); + static inline void ena_com_unmask_intr(struct ena_com_io_cq *io_cq, struct ena_eth_io_intr_reg *intr_reg) { diff --git a/drivers/net/ethernet/amazon/ena/ena_netdev.c b/drivers/net/ethernet/amazon/ena/ena_netdev.c index 97c5a89a9cf7..a6f283232cb7 100644 --- a/drivers/net/ethernet/amazon/ena/ena_netdev.c +++ b/drivers/net/ethernet/amazon/ena/ena_netdev.c @@ -158,6 +158,8 @@ static void ena_init_io_rings_common(struct ena_adapter *adapter, ring->per_napi_packets = 0; ring->per_napi_bytes = 0; ring->cpu = 0; + ring->first_interrupt = false; + ring->no_interrupt_event_cnt = 0; u64_stats_init(&ring->syncp); } @@ -1274,6 +1276,9 @@ static irqreturn_t ena_intr_msix_io(int irq, void *data) { struct ena_napi *ena_napi = data; + ena_napi->tx_ring->first_interrupt = true; + ena_napi->rx_ring->first_interrupt = true; + napi_schedule_irqoff(&ena_napi->napi); return IRQ_HANDLED; @@ -2648,8 +2653,32 @@ static void ena_fw_reset_device(struct work_struct *work) rtnl_unlock(); } -static int check_missing_comp_in_queue(struct ena_adapter *adapter, - struct ena_ring *tx_ring) +static int check_for_rx_interrupt_queue(struct ena_adapter *adapter, + struct ena_ring *rx_ring) +{ + if (likely(rx_ring->first_interrupt)) + return 0; + + if (ena_com_cq_empty(rx_ring->ena_com_io_cq)) + return 0; + + rx_ring->no_interrupt_event_cnt++; + + if (rx_ring->no_interrupt_event_cnt == ENA_MAX_NO_INTERRUPT_ITERATIONS) { + netif_err(adapter, rx_err, adapter->netdev, + "Potential MSIX issue on Rx side Queue = %d. Reset the device\n", + rx_ring->qid); + adapter->reset_reason = ENA_REGS_RESET_MISS_INTERRUPT; + smp_mb__before_atomic(); + set_bit(ENA_FLAG_TRIGGER_RESET, &adapter->flags); + return -EIO; + } + + return 0; +} + +static int check_missing_comp_in_tx_queue(struct ena_adapter *adapter, + struct ena_ring *tx_ring) { struct ena_tx_buffer *tx_buf; unsigned long last_jiffies; @@ -2659,8 +2688,27 @@ static int check_missing_comp_in_queue(struct ena_adapter *adapter, for (i = 0; i < tx_ring->ring_size; i++) { tx_buf = &tx_ring->tx_buffer_info[i]; last_jiffies = tx_buf->last_jiffies; - if (unlikely(last_jiffies && - time_is_before_jiffies(last_jiffies + adapter->missing_tx_completion_to))) { + + if (last_jiffies == 0) + /* no pending Tx at this location */ + continue; + + if (unlikely(!tx_ring->first_interrupt && time_is_before_jiffies(last_jiffies + + 2 * adapter->missing_tx_completion_to))) { + /* If after graceful period interrupt is still not + * received, we schedule a reset + */ + netif_err(adapter, tx_err, adapter->netdev, + "Potential MSIX issue on Tx side Queue = %d. Reset the device\n", + tx_ring->qid); + adapter->reset_reason = ENA_REGS_RESET_MISS_INTERRUPT; + smp_mb__before_atomic(); + set_bit(ENA_FLAG_TRIGGER_RESET, &adapter->flags); + return -EIO; + } + + if (unlikely(time_is_before_jiffies(last_jiffies + + adapter->missing_tx_completion_to))) { if (!tx_buf->print_once) netif_notice(adapter, tx_err, adapter->netdev, "Found a Tx that wasn't completed on time, qid %d, index %d.\n", @@ -2689,9 +2737,10 @@ static int check_missing_comp_in_queue(struct ena_adapter *adapter, return rc; } -static void check_for_missing_tx_completions(struct ena_adapter *adapter) +static void check_for_missing_completions(struct ena_adapter *adapter) { struct ena_ring *tx_ring; + struct ena_ring *rx_ring; int i, budget, rc; /* Make sure the driver doesn't turn the device in other process */ @@ -2710,8 +2759,13 @@ static void check_for_missing_tx_completions(struct ena_adapter *adapter) for (i = adapter->last_monitored_tx_qid; i < adapter->num_queues; i++) { tx_ring = &adapter->tx_ring[i]; + rx_ring = &adapter->rx_ring[i]; + + rc = check_missing_comp_in_tx_queue(adapter, tx_ring); + if (unlikely(rc)) + return; - rc = check_missing_comp_in_queue(adapter, tx_ring); + rc = check_for_rx_interrupt_queue(adapter, rx_ring); if (unlikely(rc)) return; @@ -2870,7 +2924,7 @@ static void ena_timer_service(struct timer_list *t) check_for_admin_com_state(adapter); - check_for_missing_tx_completions(adapter); + check_for_missing_completions(adapter); check_for_empty_rx_ring(adapter); diff --git a/drivers/net/ethernet/amazon/ena/ena_netdev.h b/drivers/net/ethernet/amazon/ena/ena_netdev.h index 3bbc003871de..734ff2e84494 100644 --- a/drivers/net/ethernet/amazon/ena/ena_netdev.h +++ b/drivers/net/ethernet/amazon/ena/ena_netdev.h @@ -122,6 +122,7 @@ * We wait for 6 sec just to be on the safe side. */ #define ENA_DEVICE_KALIVE_TIMEOUT (6 * HZ) +#define ENA_MAX_NO_INTERRUPT_ITERATIONS 3 #define ENA_MMIO_DISABLE_REG_READ BIT(0) @@ -236,6 +237,9 @@ struct ena_ring { /* The maximum header length the device can handle */ u8 tx_max_header_size; + bool first_interrupt; + u16 no_interrupt_event_cnt; + /* cpu for TPH */ int cpu; /* number of tx/rx_buffer_info's entries */ diff --git a/drivers/net/ethernet/amazon/ena/ena_regs_defs.h b/drivers/net/ethernet/amazon/ena/ena_regs_defs.h index 9aec43c5bba8..48ca97fbe7bc 100644 --- a/drivers/net/ethernet/amazon/ena/ena_regs_defs.h +++ b/drivers/net/ethernet/amazon/ena/ena_regs_defs.h @@ -60,6 +60,8 @@ enum ena_regs_reset_reason_types { ENA_REGS_RESET_USER_TRIGGER = 12, ENA_REGS_RESET_GENERIC = 13, + + ENA_REGS_RESET_MISS_INTERRUPT = 14, }; /* ena_registers offsets */ -- 2.11.0