[v3,15/16] can: m_can: Implement BQL

Message ID 20230315110546.2518305-16-msp@baylibre.com
State New
Headers
Series can: m_can: Optimizations for m_can/tcan part 2 |

Commit Message

Markus Schneider-Pargmann March 15, 2023, 11:05 a.m. UTC
  Implement byte queue limiting in preparation for the use of xmit_more().

Signed-off-by: Markus Schneider-Pargmann <msp@baylibre.com>
---
 drivers/net/can/m_can/m_can.c | 49 +++++++++++++++++++++++++----------
 1 file changed, 35 insertions(+), 14 deletions(-)
  

Comments

Simon Horman March 17, 2023, 4:05 p.m. UTC | #1
On Wed, Mar 15, 2023 at 12:05:45PM +0100, Markus Schneider-Pargmann wrote:
> Implement byte queue limiting in preparation for the use of xmit_more().
> 
> Signed-off-by: Markus Schneider-Pargmann <msp@baylibre.com>

Nits below aside, this looks good to me.

Reviewed-by: Simon Horman <simon.horman@corigine.com>

> ---
>  drivers/net/can/m_can/m_can.c | 49 +++++++++++++++++++++++++----------
>  1 file changed, 35 insertions(+), 14 deletions(-)
> 
> diff --git a/drivers/net/can/m_can/m_can.c b/drivers/net/can/m_can/m_can.c
> index 3cb3d01e1a61..63d6e95717e3 100644
> --- a/drivers/net/can/m_can/m_can.c
> +++ b/drivers/net/can/m_can/m_can.c

...

> @@ -999,29 +1001,34 @@ 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(&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,
> +			    int transmitted_frame_len)

nit: I think unsigned int would be a better type for transmitted_frame_len,
     as that is the type of the 3rd argument to netdev_completed_queue()

>  {
>  	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);
> @@ -1060,6 +1067,7 @@ static int m_can_echo_tx_event(struct net_device *dev)
>  	int err = 0;
>  	unsigned int msg_mark;
>  	int processed = 0;
> +	int processed_frame_len = 0;

Likewise, here.

>  	struct m_can_classdev *cdev = netdev_priv(dev);
>  
> @@ -1088,7 +1096,9 @@ 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;
>  	}
>  
> @@ -1096,7 +1106,7 @@ 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;
>  }

...
  

Patch

diff --git a/drivers/net/can/m_can/m_can.c b/drivers/net/can/m_can/m_can.c
index 3cb3d01e1a61..63d6e95717e3 100644
--- a/drivers/net/can/m_can/m_can.c
+++ b/drivers/net/can/m_can/m_can.c
@@ -445,6 +445,8 @@  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);
@@ -999,29 +1001,34 @@  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(&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,
+			    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);
@@ -1060,6 +1067,7 @@  static int m_can_echo_tx_event(struct net_device *dev)
 	int err = 0;
 	unsigned int msg_mark;
 	int processed = 0;
+	int processed_frame_len = 0;
 
 	struct m_can_classdev *cdev = netdev_priv(dev);
 
@@ -1088,7 +1096,9 @@  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;
 	}
 
@@ -1096,7 +1106,7 @@  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;
 }
@@ -1187,11 +1197,12 @@  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)) {
@@ -1720,6 +1731,7 @@  static netdev_tx_t m_can_tx_handler(struct m_can_classdev *cdev,
 	u32 cccr, fdflags;
 	int err;
 	int 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 */
@@ -1765,7 +1777,7 @@  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 */
@@ -1804,7 +1816,7 @@  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));
@@ -1875,14 +1887,23 @@  static netdev_tx_t m_can_start_xmit(struct sk_buff *skb,
 				    struct net_device *dev)
 {
 	struct m_can_classdev *cdev = netdev_priv(dev);
+	netdev_tx_t ret;
+	unsigned int frame_len;
 
 	if (can_dev_dropped_skb(dev, skb))
 		return NETDEV_TX_OK;
 
+	frame_len = can_skb_get_frame_len(skb);
+
 	if (cdev->is_peripheral)
-		return m_can_start_peripheral_xmit(cdev, skb);
+		ret = m_can_start_peripheral_xmit(cdev, skb);
 	else
-		return m_can_start_fast_xmit(cdev, skb);
+		ret = m_can_start_fast_xmit(cdev, skb);
+
+	if (ret == NETDEV_TX_OK)
+		netdev_sent_queue(dev, frame_len);
+
+	return ret;
 }
 
 static int m_can_open(struct net_device *dev)