From: Torin Cooper-Bennun <torin@xxxxxxxxxxxxxxxxxx> For peripheral devices, m_can sent skbs directly from a threaded irq instead of from a softirq context, breaking the tcan4x5x peripheral driver completely. This patch transitions the driver to use the rx-offload helper for peripherals, ensuring the skbs are sent from the correct context, with h/w timestamping to ensure correct ordering. Link: https://lore.kernel.org/r/20210308102427.63916-4-torin@xxxxxxxxxxxxxxxxxx Signed-off-by: Torin Cooper-Bennun <torin@xxxxxxxxxxxxxxxxxx> [mkl: m_can_class_register(): update error handling] Signed-off-by: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx> --- Hello, for completeness here the v3 of Torin's patch. changes since v2: - fixed commenting style - add some missing variable initialization - m_can_class_register(): update error handling regards, Marc drivers/net/can/m_can/m_can.c | 121 +++++++++++++++++++++++++++++----- drivers/net/can/m_can/m_can.h | 2 + 2 files changed, 107 insertions(+), 16 deletions(-) diff --git a/drivers/net/can/m_can/m_can.c b/drivers/net/can/m_can/m_can.c index 98f7c6514937..7bd67928d78f 100644 --- a/drivers/net/can/m_can/m_can.c +++ b/drivers/net/can/m_can/m_can.c @@ -457,6 +457,21 @@ static void m_can_clean(struct net_device *net) } } +/* For peripherals, pass skb to rx-offload, which will push skb from + * napi. For non-peripherals, RX is done in napi already, so push + * directly. timestamp is used to ensure good skb ordering in + * rx-offload and is ignored for non-peripherals. +*/ +static void m_can_receive_skb(struct m_can_classdev *cdev, + struct sk_buff *skb, + u32 timestamp) +{ + if (cdev->is_peripheral) + can_rx_offload_queue_sorted(&cdev->offload, skb, timestamp); + else + netif_receive_skb(skb); +} + static void m_can_read_fifo(struct net_device *dev, u32 rxfs) { struct net_device_stats *stats = &dev->stats; @@ -464,6 +479,7 @@ static void m_can_read_fifo(struct net_device *dev, u32 rxfs) struct canfd_frame *cf; struct sk_buff *skb; u32 id, fgi, dlc; + u32 timestamp = 0; int i; /* calculate the fifo get index for where to read data */ @@ -512,7 +528,9 @@ static void m_can_read_fifo(struct net_device *dev, u32 rxfs) stats->rx_packets++; stats->rx_bytes += cf->len; - netif_receive_skb(skb); + timestamp = FIELD_GET(RX_BUF_RXTS_MASK, dlc); + + m_can_receive_skb(cdev, skb, timestamp); } static int m_can_do_rx_poll(struct net_device *dev, int quota) @@ -546,9 +564,11 @@ static int m_can_do_rx_poll(struct net_device *dev, int quota) static int m_can_handle_lost_msg(struct net_device *dev) { + struct m_can_classdev *cdev = netdev_priv(dev); struct net_device_stats *stats = &dev->stats; struct sk_buff *skb; struct can_frame *frame; + u32 timestamp = 0; netdev_err(dev, "msg lost in rxf0\n"); @@ -562,7 +582,10 @@ static int m_can_handle_lost_msg(struct net_device *dev) frame->can_id |= CAN_ERR_CRTL; frame->data[1] = CAN_ERR_CRTL_RX_OVERFLOW; - netif_receive_skb(skb); + if (cdev->is_peripheral) + timestamp = m_can_get_timestamp(cdev); + + m_can_receive_skb(cdev, skb, timestamp); return 1; } @@ -574,6 +597,7 @@ static int m_can_handle_lec_err(struct net_device *dev, struct net_device_stats *stats = &dev->stats; struct can_frame *cf; struct sk_buff *skb; + u32 timestamp = 0; cdev->can.can_stats.bus_error++; stats->rx_errors++; @@ -619,7 +643,11 @@ static int m_can_handle_lec_err(struct net_device *dev, stats->rx_packets++; stats->rx_bytes += cf->len; - netif_receive_skb(skb); + + if (cdev->is_peripheral) + timestamp = m_can_get_timestamp(cdev); + + m_can_receive_skb(cdev, skb, timestamp); return 1; } @@ -677,6 +705,7 @@ static int m_can_handle_state_change(struct net_device *dev, struct sk_buff *skb; struct can_berr_counter bec; unsigned int ecr; + u32 timestamp = 0; switch (new_state) { case CAN_STATE_ERROR_WARNING: @@ -738,7 +767,11 @@ static int m_can_handle_state_change(struct net_device *dev, stats->rx_packets++; stats->rx_bytes += cf->len; - netif_receive_skb(skb); + + if (cdev->is_peripheral) + timestamp = m_can_get_timestamp(cdev); + + m_can_receive_skb(cdev, skb, timestamp); return 1; } @@ -803,6 +836,7 @@ static int m_can_handle_protocol_error(struct net_device *dev, u32 irqstatus) struct m_can_classdev *cdev = netdev_priv(dev); struct can_frame *cf; struct sk_buff *skb; + u32 timestamp = 0; /* propagate the error condition to the CAN stack */ skb = alloc_can_err_skb(dev, &cf); @@ -824,7 +858,11 @@ static int m_can_handle_protocol_error(struct net_device *dev, u32 irqstatus) netdev_dbg(dev, "allocation of skb failed\n"); return 0; } - netif_receive_skb(skb); + + if (cdev->is_peripheral) + timestamp = m_can_get_timestamp(cdev); + + m_can_receive_skb(cdev, skb, timestamp); return 1; } @@ -925,6 +963,29 @@ static int m_can_poll(struct napi_struct *napi, int quota) return work_done; } +/* Echo tx skb and update net stats. Peripherals use rx-offload for + * echo. timestamp is used for peripherals to ensure correct ordering + * by rx-offload, and is ignored for non-peripherals. +*/ +static void m_can_tx_update_stats(struct m_can_classdev *cdev, + unsigned int msg_mark, + u32 timestamp) +{ + struct net_device *dev = cdev->net; + struct net_device_stats *stats = &dev->stats; + + if (cdev->is_peripheral) + stats->tx_bytes += + can_rx_offload_get_echo_skb(&cdev->offload, + msg_mark, + timestamp, + NULL); + else + stats->tx_bytes += can_get_echo_skb(dev, msg_mark, NULL); + + stats->tx_packets++; +} + static void m_can_echo_tx_event(struct net_device *dev) { u32 txe_count = 0; @@ -934,7 +995,6 @@ static void m_can_echo_tx_event(struct net_device *dev) unsigned int msg_mark; struct m_can_classdev *cdev = netdev_priv(dev); - struct net_device_stats *stats = &dev->stats; /* read tx event fifo status */ m_can_txefs = m_can_read(cdev, M_CAN_TXEFS); @@ -944,21 +1004,23 @@ static void m_can_echo_tx_event(struct net_device *dev) /* Get and process all sent elements */ for (i = 0; i < txe_count; i++) { + u32 txe, timestamp = 0; + /* retrieve get index */ fgi = (m_can_read(cdev, M_CAN_TXEFS) & TXEFS_EFGI_MASK) >> TXEFS_EFGI_SHIFT; - /* get message marker */ - msg_mark = (m_can_txe_fifo_read(cdev, fgi, 4) & - TX_EVENT_MM_MASK) >> TX_EVENT_MM_SHIFT; + /* get message marker, timestamp */ + txe = m_can_txe_fifo_read(cdev, fgi, 4); + msg_mark = (txe & TX_EVENT_MM_MASK) >> TX_EVENT_MM_SHIFT; + timestamp = FIELD_GET(TX_EVENT_TXTS_MASK, txe); /* ack txe element */ m_can_write(cdev, M_CAN_TXEFA, (TXEFA_EFAI_MASK & (fgi << TXEFA_EFAI_SHIFT))); /* update stats */ - stats->tx_bytes += can_get_echo_skb(dev, msg_mark, NULL); - stats->tx_packets++; + m_can_tx_update_stats(cdev, msg_mark, timestamp); } } @@ -966,7 +1028,6 @@ static irqreturn_t m_can_isr(int irq, void *dev_id) { struct net_device *dev = (struct net_device *)dev_id; struct m_can_classdev *cdev = netdev_priv(dev); - struct net_device_stats *stats = &dev->stats; u32 ir; if (pm_runtime_suspended(cdev->dev)) @@ -999,8 +1060,12 @@ static irqreturn_t m_can_isr(int irq, void *dev_id) if (cdev->version == 30) { if (ir & IR_TC) { /* Transmission Complete Interrupt*/ - stats->tx_bytes += can_get_echo_skb(dev, 0, NULL); - stats->tx_packets++; + u32 timestamp = 0; + + if (cdev->is_peripheral) + timestamp = m_can_get_timestamp(cdev); + m_can_tx_update_stats(cdev, 0, timestamp); + can_led_event(dev, CAN_LED_EVENT_TX); netif_wake_queue(dev); } @@ -1461,6 +1526,9 @@ static int m_can_close(struct net_device *dev) cdev->tx_wq = NULL; } + if (cdev->is_peripheral) + can_rx_offload_disable(&cdev->offload); + close_candev(dev); can_led_event(dev, CAN_LED_EVENT_STOP); @@ -1659,6 +1727,9 @@ static int m_can_open(struct net_device *dev) goto exit_disable_clks; } + if (cdev->is_peripheral) + can_rx_offload_enable(&cdev->offload); + /* register interrupt handler */ if (cdev->is_peripheral) { cdev->tx_skb = NULL; @@ -1700,6 +1771,8 @@ static int m_can_open(struct net_device *dev) if (cdev->is_peripheral) destroy_workqueue(cdev->tx_wq); out_wq_fail: + if (cdev->is_peripheral) + can_rx_offload_disable(&cdev->offload); close_candev(dev); exit_disable_clks: m_can_clk_stop(cdev); @@ -1848,15 +1921,22 @@ int m_can_class_register(struct m_can_classdev *cdev) return ret; } + if (cdev->is_peripheral) { + ret = can_rx_offload_add_manual(cdev->net, &cdev->offload, + M_CAN_NAPI_WEIGHT); + if (ret) + goto clk_disable; + } + ret = m_can_dev_setup(cdev); if (ret) - goto clk_disable; + goto rx_offload_del; ret = register_m_can_dev(cdev->net); if (ret) { dev_err(cdev->dev, "registering %s failed (err=%d)\n", cdev->net->name, ret); - goto clk_disable; + goto rx_offload_del; } devm_can_led_init(cdev->net); @@ -1869,6 +1949,13 @@ int m_can_class_register(struct m_can_classdev *cdev) /* Probe finished * Stop clocks. They will be reactivated once the M_CAN device is opened */ + m_can_clk_stop(cdev); + + return 0; + +rx_offload_del: + if (cdev->is_peripheral) + can_rx_offload_del(&cdev->offload); clk_disable: m_can_clk_stop(cdev); @@ -1878,6 +1965,8 @@ EXPORT_SYMBOL_GPL(m_can_class_register); void m_can_class_unregister(struct m_can_classdev *cdev) { + if (cdev->is_peripheral) + can_rx_offload_del(&cdev->offload); unregister_candev(cdev->net); } EXPORT_SYMBOL_GPL(m_can_class_unregister); diff --git a/drivers/net/can/m_can/m_can.h b/drivers/net/can/m_can/m_can.h index 3fda84cef351..ace071c3e58c 100644 --- a/drivers/net/can/m_can/m_can.h +++ b/drivers/net/can/m_can/m_can.h @@ -8,6 +8,7 @@ #include <linux/can/core.h> #include <linux/can/led.h> +#include <linux/can/rx-offload.h> #include <linux/completion.h> #include <linux/device.h> #include <linux/dma-mapping.h> @@ -71,6 +72,7 @@ struct m_can_ops { struct m_can_classdev { struct can_priv can; + struct can_rx_offload offload; struct napi_struct napi; struct net_device *net; struct device *dev; -- 2.30.1
