From 9176bd205ee0b2cd35073a9973c2a0936bcb579e Mon Sep 17 00:00:00 2001 From: Axel Forsman Date: Tue, 20 May 2025 13:43:30 +0200 Subject: [PATCH 1/3] can: kvaser_pciefd: Force IRQ edge in case of nested IRQ Avoid the driver missing IRQs by temporarily masking IRQs in the ISR to enforce an edge even if a different IRQ is signalled before handled IRQs are cleared. Fixes: 48f827d4f48f ("can: kvaser_pciefd: Move reset of DMA RX buffers to the end of the ISR") Cc: stable@vger.kernel.org Signed-off-by: Axel Forsman Tested-by: Jimmy Assarsson Reviewed-by: Jimmy Assarsson Link: https://patch.msgid.link/20250520114332.8961-2-axfo@kvaser.com Signed-off-by: Marc Kleine-Budde --- drivers/net/can/kvaser_pciefd.c | 83 ++++++++++++++++----------------- 1 file changed, 39 insertions(+), 44 deletions(-) diff --git a/drivers/net/can/kvaser_pciefd.c b/drivers/net/can/kvaser_pciefd.c index cf0d51805272..9cc9176c2058 100644 --- a/drivers/net/can/kvaser_pciefd.c +++ b/drivers/net/can/kvaser_pciefd.c @@ -1646,24 +1646,28 @@ static int kvaser_pciefd_read_buffer(struct kvaser_pciefd *pcie, int dma_buf) return res; } -static u32 kvaser_pciefd_receive_irq(struct kvaser_pciefd *pcie) +static void kvaser_pciefd_receive_irq(struct kvaser_pciefd *pcie) { + void __iomem *srb_cmd_reg = KVASER_PCIEFD_SRB_ADDR(pcie) + KVASER_PCIEFD_SRB_CMD_REG; u32 irq = ioread32(KVASER_PCIEFD_SRB_ADDR(pcie) + KVASER_PCIEFD_SRB_IRQ_REG); - if (irq & KVASER_PCIEFD_SRB_IRQ_DPD0) - kvaser_pciefd_read_buffer(pcie, 0); + iowrite32(irq, KVASER_PCIEFD_SRB_ADDR(pcie) + KVASER_PCIEFD_SRB_IRQ_REG); - if (irq & KVASER_PCIEFD_SRB_IRQ_DPD1) + if (irq & KVASER_PCIEFD_SRB_IRQ_DPD0) { + kvaser_pciefd_read_buffer(pcie, 0); + iowrite32(KVASER_PCIEFD_SRB_CMD_RDB0, srb_cmd_reg); /* Rearm buffer */ + } + + if (irq & KVASER_PCIEFD_SRB_IRQ_DPD1) { kvaser_pciefd_read_buffer(pcie, 1); + iowrite32(KVASER_PCIEFD_SRB_CMD_RDB1, srb_cmd_reg); /* Rearm buffer */ + } if (unlikely(irq & KVASER_PCIEFD_SRB_IRQ_DOF0 || irq & KVASER_PCIEFD_SRB_IRQ_DOF1 || irq & KVASER_PCIEFD_SRB_IRQ_DUF0 || irq & KVASER_PCIEFD_SRB_IRQ_DUF1)) dev_err(&pcie->pci->dev, "DMA IRQ error 0x%08X\n", irq); - - iowrite32(irq, KVASER_PCIEFD_SRB_ADDR(pcie) + KVASER_PCIEFD_SRB_IRQ_REG); - return irq; } static void kvaser_pciefd_transmit_irq(struct kvaser_pciefd_can *can) @@ -1691,29 +1695,22 @@ static irqreturn_t kvaser_pciefd_irq_handler(int irq, void *dev) struct kvaser_pciefd *pcie = (struct kvaser_pciefd *)dev; const struct kvaser_pciefd_irq_mask *irq_mask = pcie->driver_data->irq_mask; u32 pci_irq = ioread32(KVASER_PCIEFD_PCI_IRQ_ADDR(pcie)); - u32 srb_irq = 0; - u32 srb_release = 0; int i; if (!(pci_irq & irq_mask->all)) return IRQ_NONE; + iowrite32(0, KVASER_PCIEFD_PCI_IEN_ADDR(pcie)); + if (pci_irq & irq_mask->kcan_rx0) - srb_irq = kvaser_pciefd_receive_irq(pcie); + kvaser_pciefd_receive_irq(pcie); for (i = 0; i < pcie->nr_channels; i++) { if (pci_irq & irq_mask->kcan_tx[i]) kvaser_pciefd_transmit_irq(pcie->can[i]); } - if (srb_irq & KVASER_PCIEFD_SRB_IRQ_DPD0) - srb_release |= KVASER_PCIEFD_SRB_CMD_RDB0; - - if (srb_irq & KVASER_PCIEFD_SRB_IRQ_DPD1) - srb_release |= KVASER_PCIEFD_SRB_CMD_RDB1; - - if (srb_release) - iowrite32(srb_release, KVASER_PCIEFD_SRB_ADDR(pcie) + KVASER_PCIEFD_SRB_CMD_REG); + iowrite32(irq_mask->all, KVASER_PCIEFD_PCI_IEN_ADDR(pcie)); return IRQ_HANDLED; } @@ -1733,13 +1730,22 @@ static void kvaser_pciefd_teardown_can_ctrls(struct kvaser_pciefd *pcie) } } +static void kvaser_pciefd_disable_irq_srcs(struct kvaser_pciefd *pcie) +{ + unsigned int i; + + /* Masking PCI_IRQ is insufficient as running ISR will unmask it */ + iowrite32(0, KVASER_PCIEFD_SRB_ADDR(pcie) + KVASER_PCIEFD_SRB_IEN_REG); + for (i = 0; i < pcie->nr_channels; ++i) + iowrite32(0, pcie->can[i]->reg_base + KVASER_PCIEFD_KCAN_IEN_REG); +} + static int kvaser_pciefd_probe(struct pci_dev *pdev, const struct pci_device_id *id) { int ret; struct kvaser_pciefd *pcie; const struct kvaser_pciefd_irq_mask *irq_mask; - void __iomem *irq_en_base; pcie = devm_kzalloc(&pdev->dev, sizeof(*pcie), GFP_KERNEL); if (!pcie) @@ -1805,8 +1811,7 @@ static int kvaser_pciefd_probe(struct pci_dev *pdev, KVASER_PCIEFD_SRB_ADDR(pcie) + KVASER_PCIEFD_SRB_IEN_REG); /* Enable PCI interrupts */ - irq_en_base = KVASER_PCIEFD_PCI_IEN_ADDR(pcie); - iowrite32(irq_mask->all, irq_en_base); + iowrite32(irq_mask->all, KVASER_PCIEFD_PCI_IEN_ADDR(pcie)); /* Ready the DMA buffers */ iowrite32(KVASER_PCIEFD_SRB_CMD_RDB0, KVASER_PCIEFD_SRB_ADDR(pcie) + KVASER_PCIEFD_SRB_CMD_REG); @@ -1820,8 +1825,7 @@ static int kvaser_pciefd_probe(struct pci_dev *pdev, return 0; err_free_irq: - /* Disable PCI interrupts */ - iowrite32(0, irq_en_base); + kvaser_pciefd_disable_irq_srcs(pcie); free_irq(pcie->pci->irq, pcie); err_pci_free_irq_vectors: @@ -1844,35 +1848,26 @@ static int kvaser_pciefd_probe(struct pci_dev *pdev, return ret; } -static void kvaser_pciefd_remove_all_ctrls(struct kvaser_pciefd *pcie) -{ - int i; - - for (i = 0; i < pcie->nr_channels; i++) { - struct kvaser_pciefd_can *can = pcie->can[i]; - - if (can) { - iowrite32(0, can->reg_base + KVASER_PCIEFD_KCAN_IEN_REG); - unregister_candev(can->can.dev); - timer_delete(&can->bec_poll_timer); - kvaser_pciefd_pwm_stop(can); - free_candev(can->can.dev); - } - } -} - static void kvaser_pciefd_remove(struct pci_dev *pdev) { struct kvaser_pciefd *pcie = pci_get_drvdata(pdev); + unsigned int i; - kvaser_pciefd_remove_all_ctrls(pcie); + for (i = 0; i < pcie->nr_channels; ++i) { + struct kvaser_pciefd_can *can = pcie->can[i]; - /* Disable interrupts */ - iowrite32(0, KVASER_PCIEFD_SRB_ADDR(pcie) + KVASER_PCIEFD_SRB_CTRL_REG); - iowrite32(0, KVASER_PCIEFD_PCI_IEN_ADDR(pcie)); + unregister_candev(can->can.dev); + timer_delete(&can->bec_poll_timer); + kvaser_pciefd_pwm_stop(can); + } + kvaser_pciefd_disable_irq_srcs(pcie); free_irq(pcie->pci->irq, pcie); pci_free_irq_vectors(pcie->pci); + + for (i = 0; i < pcie->nr_channels; ++i) + free_candev(pcie->can[i]->can.dev); + pci_iounmap(pdev, pcie->reg_base); pci_release_regions(pdev); pci_disable_device(pdev); From 8256e0ca601051933e9395746817f3801fa9a6bf Mon Sep 17 00:00:00 2001 From: Axel Forsman Date: Tue, 20 May 2025 13:43:31 +0200 Subject: [PATCH 2/3] can: kvaser_pciefd: Fix echo_skb race The functions kvaser_pciefd_start_xmit() and kvaser_pciefd_handle_ack_packet() raced to stop/wake TX queues and get/put echo skbs, as kvaser_pciefd_can->echo_lock was only ever taken when transmitting and KCAN_TX_NR_PACKETS_CURRENT gets decremented prior to handling of ACKs. E.g., this caused the following error: can_put_echo_skb: BUG! echo_skb 5 is occupied! Instead, use the synchronization helpers in netdev_queues.h. As those piggyback on BQL barriers, start updating in-flight packets and bytes counts as well. Cc: stable@vger.kernel.org Signed-off-by: Axel Forsman Tested-by: Jimmy Assarsson Reviewed-by: Jimmy Assarsson Link: https://patch.msgid.link/20250520114332.8961-3-axfo@kvaser.com Signed-off-by: Marc Kleine-Budde --- drivers/net/can/kvaser_pciefd.c | 93 +++++++++++++++++++++------------ 1 file changed, 59 insertions(+), 34 deletions(-) diff --git a/drivers/net/can/kvaser_pciefd.c b/drivers/net/can/kvaser_pciefd.c index 9cc9176c2058..a61cbade96d9 100644 --- a/drivers/net/can/kvaser_pciefd.c +++ b/drivers/net/can/kvaser_pciefd.c @@ -16,6 +16,7 @@ #include #include #include +#include MODULE_LICENSE("Dual BSD/GPL"); MODULE_AUTHOR("Kvaser AB "); @@ -410,10 +411,13 @@ struct kvaser_pciefd_can { void __iomem *reg_base; struct can_berr_counter bec; u8 cmd_seq; + u8 tx_max_count; + u8 tx_idx; + u8 ack_idx; int err_rep_cnt; - int echo_idx; + unsigned int completed_tx_pkts; + unsigned int completed_tx_bytes; spinlock_t lock; /* Locks sensitive registers (e.g. MODE) */ - spinlock_t echo_lock; /* Locks the message echo buffer */ struct timer_list bec_poll_timer; struct completion start_comp, flush_comp; }; @@ -714,6 +718,9 @@ static int kvaser_pciefd_open(struct net_device *netdev) int ret; struct kvaser_pciefd_can *can = netdev_priv(netdev); + can->tx_idx = 0; + can->ack_idx = 0; + ret = open_candev(netdev); if (ret) return ret; @@ -745,21 +752,26 @@ static int kvaser_pciefd_stop(struct net_device *netdev) timer_delete(&can->bec_poll_timer); } can->can.state = CAN_STATE_STOPPED; + netdev_reset_queue(netdev); close_candev(netdev); return ret; } +static unsigned int kvaser_pciefd_tx_avail(const struct kvaser_pciefd_can *can) +{ + return can->tx_max_count - (READ_ONCE(can->tx_idx) - READ_ONCE(can->ack_idx)); +} + static int kvaser_pciefd_prepare_tx_packet(struct kvaser_pciefd_tx_packet *p, - struct kvaser_pciefd_can *can, + struct can_priv *can, u8 seq, struct sk_buff *skb) { struct canfd_frame *cf = (struct canfd_frame *)skb->data; int packet_size; - int seq = can->echo_idx; memset(p, 0, sizeof(*p)); - if (can->can.ctrlmode & CAN_CTRLMODE_ONE_SHOT) + if (can->ctrlmode & CAN_CTRLMODE_ONE_SHOT) p->header[1] |= KVASER_PCIEFD_TPACKET_SMS; if (cf->can_id & CAN_RTR_FLAG) @@ -782,7 +794,7 @@ static int kvaser_pciefd_prepare_tx_packet(struct kvaser_pciefd_tx_packet *p, } else { p->header[1] |= FIELD_PREP(KVASER_PCIEFD_RPACKET_DLC_MASK, - can_get_cc_dlc((struct can_frame *)cf, can->can.ctrlmode)); + can_get_cc_dlc((struct can_frame *)cf, can->ctrlmode)); } p->header[1] |= FIELD_PREP(KVASER_PCIEFD_PACKET_SEQ_MASK, seq); @@ -797,22 +809,24 @@ static netdev_tx_t kvaser_pciefd_start_xmit(struct sk_buff *skb, struct net_device *netdev) { struct kvaser_pciefd_can *can = netdev_priv(netdev); - unsigned long irq_flags; struct kvaser_pciefd_tx_packet packet; + unsigned int seq = can->tx_idx & (can->can.echo_skb_max - 1); + unsigned int frame_len; int nr_words; - u8 count; if (can_dev_dropped_skb(netdev, skb)) return NETDEV_TX_OK; + if (!netif_subqueue_maybe_stop(netdev, 0, kvaser_pciefd_tx_avail(can), 1, 1)) + return NETDEV_TX_BUSY; - nr_words = kvaser_pciefd_prepare_tx_packet(&packet, can, skb); + nr_words = kvaser_pciefd_prepare_tx_packet(&packet, &can->can, seq, skb); - spin_lock_irqsave(&can->echo_lock, irq_flags); /* Prepare and save echo skb in internal slot */ - can_put_echo_skb(skb, netdev, can->echo_idx, 0); - - /* Move echo index to the next slot */ - can->echo_idx = (can->echo_idx + 1) % can->can.echo_skb_max; + WRITE_ONCE(can->can.echo_skb[seq], NULL); + frame_len = can_skb_get_frame_len(skb); + can_put_echo_skb(skb, netdev, seq, frame_len); + netdev_sent_queue(netdev, frame_len); + WRITE_ONCE(can->tx_idx, can->tx_idx + 1); /* Write header to fifo */ iowrite32(packet.header[0], @@ -836,14 +850,7 @@ static netdev_tx_t kvaser_pciefd_start_xmit(struct sk_buff *skb, KVASER_PCIEFD_KCAN_FIFO_LAST_REG); } - count = FIELD_GET(KVASER_PCIEFD_KCAN_TX_NR_PACKETS_CURRENT_MASK, - ioread32(can->reg_base + KVASER_PCIEFD_KCAN_TX_NR_PACKETS_REG)); - /* No room for a new message, stop the queue until at least one - * successful transmit - */ - if (count >= can->can.echo_skb_max || can->can.echo_skb[can->echo_idx]) - netif_stop_queue(netdev); - spin_unlock_irqrestore(&can->echo_lock, irq_flags); + netif_subqueue_maybe_stop(netdev, 0, kvaser_pciefd_tx_avail(can), 1, 1); return NETDEV_TX_OK; } @@ -970,6 +977,8 @@ static int kvaser_pciefd_setup_can_ctrls(struct kvaser_pciefd *pcie) can->kv_pcie = pcie; can->cmd_seq = 0; can->err_rep_cnt = 0; + can->completed_tx_pkts = 0; + can->completed_tx_bytes = 0; can->bec.txerr = 0; can->bec.rxerr = 0; @@ -983,11 +992,10 @@ static int kvaser_pciefd_setup_can_ctrls(struct kvaser_pciefd *pcie) tx_nr_packets_max = FIELD_GET(KVASER_PCIEFD_KCAN_TX_NR_PACKETS_MAX_MASK, ioread32(can->reg_base + KVASER_PCIEFD_KCAN_TX_NR_PACKETS_REG)); + can->tx_max_count = min(KVASER_PCIEFD_CAN_TX_MAX_COUNT, tx_nr_packets_max - 1); can->can.clock.freq = pcie->freq; - can->can.echo_skb_max = min(KVASER_PCIEFD_CAN_TX_MAX_COUNT, tx_nr_packets_max - 1); - can->echo_idx = 0; - spin_lock_init(&can->echo_lock); + can->can.echo_skb_max = roundup_pow_of_two(can->tx_max_count); spin_lock_init(&can->lock); can->can.bittiming_const = &kvaser_pciefd_bittiming_const; @@ -1510,19 +1518,21 @@ static int kvaser_pciefd_handle_ack_packet(struct kvaser_pciefd *pcie, netdev_dbg(can->can.dev, "Packet was flushed\n"); } else { int echo_idx = FIELD_GET(KVASER_PCIEFD_PACKET_SEQ_MASK, p->header[0]); - int len; - u8 count; + unsigned int len, frame_len = 0; struct sk_buff *skb; + if (echo_idx != (can->ack_idx & (can->can.echo_skb_max - 1))) + return 0; skb = can->can.echo_skb[echo_idx]; - if (skb) - kvaser_pciefd_set_skb_timestamp(pcie, skb, p->timestamp); - len = can_get_echo_skb(can->can.dev, echo_idx, NULL); - count = FIELD_GET(KVASER_PCIEFD_KCAN_TX_NR_PACKETS_CURRENT_MASK, - ioread32(can->reg_base + KVASER_PCIEFD_KCAN_TX_NR_PACKETS_REG)); + if (!skb) + return 0; + kvaser_pciefd_set_skb_timestamp(pcie, skb, p->timestamp); + len = can_get_echo_skb(can->can.dev, echo_idx, &frame_len); - if (count < can->can.echo_skb_max && netif_queue_stopped(can->can.dev)) - netif_wake_queue(can->can.dev); + /* Pairs with barrier in kvaser_pciefd_start_xmit() */ + smp_store_release(&can->ack_idx, can->ack_idx + 1); + can->completed_tx_pkts++; + can->completed_tx_bytes += frame_len; if (!one_shot_fail) { can->can.dev->stats.tx_bytes += len; @@ -1638,11 +1648,26 @@ static int kvaser_pciefd_read_buffer(struct kvaser_pciefd *pcie, int dma_buf) { int pos = 0; int res = 0; + unsigned int i; do { res = kvaser_pciefd_read_packet(pcie, &pos, dma_buf); } while (!res && pos > 0 && pos < KVASER_PCIEFD_DMA_SIZE); + /* Report ACKs in this buffer to BQL en masse for correct periods */ + for (i = 0; i < pcie->nr_channels; ++i) { + struct kvaser_pciefd_can *can = pcie->can[i]; + + if (!can->completed_tx_pkts) + continue; + netif_subqueue_completed_wake(can->can.dev, 0, + can->completed_tx_pkts, + can->completed_tx_bytes, + kvaser_pciefd_tx_avail(can), 1); + can->completed_tx_pkts = 0; + can->completed_tx_bytes = 0; + } + return res; } From 6d820b81c4dc4a4023e45c3cd6707a07dd838649 Mon Sep 17 00:00:00 2001 From: Axel Forsman Date: Tue, 20 May 2025 13:43:32 +0200 Subject: [PATCH 3/3] can: kvaser_pciefd: Continue parsing DMA buf after dropped RX Going bus-off on a channel doing RX could result in dropped packets. As netif_running() gets cleared before the channel abort procedure, the handling of any last RDATA packets would see netif_rx() return non-zero to signal a dropped packet. kvaser_pciefd_read_buffer() dealt with this "error" by breaking out of processing the remaining DMA RX buffer. Only return an error from kvaser_pciefd_read_buffer() due to packet corruption, otherwise handle it internally. Cc: stable@vger.kernel.org Signed-off-by: Axel Forsman Tested-by: Jimmy Assarsson Reviewed-by: Jimmy Assarsson Link: https://patch.msgid.link/20250520114332.8961-4-axfo@kvaser.com Signed-off-by: Marc Kleine-Budde --- drivers/net/can/kvaser_pciefd.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/drivers/net/can/kvaser_pciefd.c b/drivers/net/can/kvaser_pciefd.c index a61cbade96d9..f6921368cd14 100644 --- a/drivers/net/can/kvaser_pciefd.c +++ b/drivers/net/can/kvaser_pciefd.c @@ -1209,7 +1209,7 @@ static int kvaser_pciefd_handle_data_packet(struct kvaser_pciefd *pcie, skb = alloc_canfd_skb(priv->dev, &cf); if (!skb) { priv->dev->stats.rx_dropped++; - return -ENOMEM; + return 0; } cf->len = can_fd_dlc2len(dlc); @@ -1221,7 +1221,7 @@ static int kvaser_pciefd_handle_data_packet(struct kvaser_pciefd *pcie, skb = alloc_can_skb(priv->dev, (struct can_frame **)&cf); if (!skb) { priv->dev->stats.rx_dropped++; - return -ENOMEM; + return 0; } can_frame_set_cc_len((struct can_frame *)cf, dlc, priv->ctrlmode); } @@ -1239,7 +1239,9 @@ static int kvaser_pciefd_handle_data_packet(struct kvaser_pciefd *pcie, priv->dev->stats.rx_packets++; kvaser_pciefd_set_skb_timestamp(pcie, skb, p->timestamp); - return netif_rx(skb); + netif_rx(skb); + + return 0; } static void kvaser_pciefd_change_state(struct kvaser_pciefd_can *can,