Commit 251f913d authored by Markus Schneider-Pargmann's avatar Markus Schneider-Pargmann Committed by Marc Kleine-Budde
Browse files

can: m_can: Implement BQL 



Implement byte queue limiting in preparation for the use of xmit_more().

Signed-off-by: default avatarMarkus Schneider-Pargmann <msp@baylibre.com>
Link: https://lore.kernel.org/all/20240207093220.2681425-14-msp@baylibre.com


Signed-off-by: default avatarMarc Kleine-Budde <mkl@pengutronix.de>
parent 7508a10c

drivers/net/can/m_can/m_can.c

+36 −14
Original line number Diff line number Diff line
@@ -489,6 +489,8 @@ static void m_can_clean(struct net_device *net) 
	for (int i = 0; i != cdev->can.echo_skb_max; ++i)

		can_free_echo_skb(cdev->net, i, NULL);



	netdev_reset_queue(cdev->net);



	spin_lock_irqsave(&cdev->tx_handling_spinlock, irqflags);

	cdev->tx_fifo_in_flight = 0;

	spin_unlock_irqrestore(&cdev->tx_handling_spinlock, irqflags);
@@ -1043,29 +1045,34 @@ static int m_can_poll(struct napi_struct *napi, int quota) 
 * 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)

static unsigned int 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;

	unsigned int frame_len;



	if (cdev->is_peripheral)

		stats->tx_bytes +=

			can_rx_offload_get_echo_skb_queue_timestamp(&cdev->offload,

								    msg_mark,

								    timestamp,

								    NULL);

								    &frame_len);

	else

		stats->tx_bytes += can_get_echo_skb(dev, msg_mark, NULL);

		stats->tx_bytes += can_get_echo_skb(dev, msg_mark, &frame_len);



	stats->tx_packets++;



	return frame_len;

}



static void m_can_finish_tx(struct m_can_classdev *cdev, int transmitted)

static void m_can_finish_tx(struct m_can_classdev *cdev, int transmitted,

			    unsigned int transmitted_frame_len)

{

	unsigned long irqflags;



	netdev_completed_queue(cdev->net, transmitted, transmitted_frame_len);



	spin_lock_irqsave(&cdev->tx_handling_spinlock, irqflags);

	if (cdev->tx_fifo_in_flight >= cdev->tx_fifo_size && transmitted > 0)

		netif_wake_queue(cdev->net);
@@ -1104,6 +1111,7 @@ static int m_can_echo_tx_event(struct net_device *dev) 
	int err = 0;

	unsigned int msg_mark;

	int processed = 0;

	unsigned int processed_frame_len = 0;



	struct m_can_classdev *cdev = netdev_priv(dev);
@@ -1132,7 +1140,9 @@ static int m_can_echo_tx_event(struct net_device *dev) 
		fgi = (++fgi >= cdev->mcfg[MRAM_TXE].num ? 0 : fgi);



		/* update stats */

		m_can_tx_update_stats(cdev, msg_mark, timestamp);

		processed_frame_len += m_can_tx_update_stats(cdev, msg_mark,

							     timestamp);



		++processed;

	}
@@ -1140,7 +1150,7 @@ static int m_can_echo_tx_event(struct net_device *dev) 
		m_can_write(cdev, M_CAN_TXEFA, FIELD_PREP(TXEFA_EFAI_MASK,

							  ack_fgi));



	m_can_finish_tx(cdev, processed);

	m_can_finish_tx(cdev, processed, processed_frame_len);



	return err;

}
@@ -1218,11 +1228,12 @@ static irqreturn_t m_can_isr(int irq, void *dev_id) 
		if (ir & IR_TC) {

			/* Transmission Complete Interrupt*/

			u32 timestamp = 0;

			unsigned int frame_len;



			if (cdev->is_peripheral)

				timestamp = m_can_get_timestamp(cdev);

			m_can_tx_update_stats(cdev, 0, timestamp);

			m_can_finish_tx(cdev, 1);

			frame_len = m_can_tx_update_stats(cdev, 0, timestamp);

			m_can_finish_tx(cdev, 1, frame_len);

		}

	} else  {

		if (ir & (IR_TEFN | IR_TEFW)) {
@@ -1738,6 +1749,7 @@ static netdev_tx_t m_can_tx_handler(struct m_can_classdev *cdev, 
	u32 cccr, fdflags;

	int err;

	u32 putidx;

	unsigned int frame_len = can_skb_get_frame_len(skb);



	/* Generate ID field for TX buffer Element */

	/* Common to all supported M_CAN versions */
@@ -1783,7 +1795,7 @@ static netdev_tx_t m_can_tx_handler(struct m_can_classdev *cdev, 
		}

		m_can_write(cdev, M_CAN_TXBTIE, 0x1);



		can_put_echo_skb(skb, dev, 0, 0);

		can_put_echo_skb(skb, dev, 0, frame_len);



		m_can_write(cdev, M_CAN_TXBAR, 0x1);

		/* End of xmit function for version 3.0.x */
@@ -1821,7 +1833,7 @@ static netdev_tx_t m_can_tx_handler(struct m_can_classdev *cdev, 
		/* Push loopback echo.

		 * Will be looped back on TX interrupt based on message marker

		 */

		can_put_echo_skb(skb, dev, putidx, 0);

		can_put_echo_skb(skb, dev, putidx, frame_len);



		/* Enable TX FIFO element to start transfer  */

		m_can_write(cdev, M_CAN_TXBAR, (1 << putidx));
@@ -1869,11 +1881,14 @@ static netdev_tx_t m_can_start_xmit(struct sk_buff *skb, 
				    struct net_device *dev)

{

	struct m_can_classdev *cdev = netdev_priv(dev);

	unsigned int frame_len;

	netdev_tx_t ret;



	if (can_dev_dropped_skb(dev, skb))

		return NETDEV_TX_OK;



	frame_len = can_skb_get_frame_len(skb);



	if (cdev->can.state == CAN_STATE_BUS_OFF) {

		m_can_clean(cdev->net);

		return NETDEV_TX_OK;
@@ -1883,10 +1898,17 @@ static netdev_tx_t m_can_start_xmit(struct sk_buff *skb, 
	if (ret != NETDEV_TX_OK)

		return ret;



	netdev_sent_queue(dev, frame_len);



	if (cdev->is_peripheral)

		return m_can_start_peripheral_xmit(cdev, skb);

		ret = m_can_start_peripheral_xmit(cdev, skb);

	else

		return m_can_tx_handler(cdev, skb);

		ret = m_can_tx_handler(cdev, skb);



	if (ret != NETDEV_TX_OK)

		netdev_completed_queue(dev, 1, frame_len);



	return ret;

}



static enum hrtimer_restart hrtimer_callback(struct hrtimer *timer)