From: Markus Schneider-Pargmann <msp@xxxxxxxxxxxx> Combine header and data before writing to the transmit fifo to reduce the overhead for peripheral chips. Signed-off-by: Markus Schneider-Pargmann <msp@xxxxxxxxxxxx> Reviewed-by: Simon Horman <simon.horman@xxxxxxxxxxxx> Link: https://lore.kernel.org/all/20240207093220.2681425-4-msp@xxxxxxxxxxxx Signed-off-by: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx> --- drivers/net/can/m_can/m_can.c | 35 +++++++++++++++++++++-------------- 1 file changed, 21 insertions(+), 14 deletions(-) diff --git a/drivers/net/can/m_can/m_can.c b/drivers/net/can/m_can/m_can.c index 45391492339e..a01c9261331d 100644 --- a/drivers/net/can/m_can/m_can.c +++ b/drivers/net/can/m_can/m_can.c @@ -320,6 +320,12 @@ struct id_and_dlc { u32 dlc; }; +struct m_can_fifo_element { + u32 id; + u32 dlc; + u8 data[CANFD_MAX_DLEN]; +}; + static inline u32 m_can_read(struct m_can_classdev *cdev, enum m_can_reg reg) { return cdev->ops->read_reg(cdev, reg); @@ -1637,9 +1643,10 @@ static int m_can_next_echo_skb_occupied(struct net_device *dev, int putidx) static netdev_tx_t m_can_tx_handler(struct m_can_classdev *cdev) { struct canfd_frame *cf = (struct canfd_frame *)cdev->tx_skb->data; + u8 len_padded = DIV_ROUND_UP(cf->len, 4); + struct m_can_fifo_element fifo_element; struct net_device *dev = cdev->net; struct sk_buff *skb = cdev->tx_skb; - struct id_and_dlc fifo_header; u32 cccr, fdflags; u32 txfqs; int err; @@ -1650,27 +1657,27 @@ static netdev_tx_t m_can_tx_handler(struct m_can_classdev *cdev) /* Generate ID field for TX buffer Element */ /* Common to all supported M_CAN versions */ if (cf->can_id & CAN_EFF_FLAG) { - fifo_header.id = cf->can_id & CAN_EFF_MASK; - fifo_header.id |= TX_BUF_XTD; + fifo_element.id = cf->can_id & CAN_EFF_MASK; + fifo_element.id |= TX_BUF_XTD; } else { - fifo_header.id = ((cf->can_id & CAN_SFF_MASK) << 18); + fifo_element.id = ((cf->can_id & CAN_SFF_MASK) << 18); } if (cf->can_id & CAN_RTR_FLAG) - fifo_header.id |= TX_BUF_RTR; + fifo_element.id |= TX_BUF_RTR; if (cdev->version == 30) { netif_stop_queue(dev); - fifo_header.dlc = can_fd_len2dlc(cf->len) << 16; + fifo_element.dlc = can_fd_len2dlc(cf->len) << 16; /* Write the frame ID, DLC, and payload to the FIFO element. */ - err = m_can_fifo_write(cdev, 0, M_CAN_FIFO_ID, &fifo_header, 2); + err = m_can_fifo_write(cdev, 0, M_CAN_FIFO_ID, &fifo_element, 2); if (err) goto out_fail; err = m_can_fifo_write(cdev, 0, M_CAN_FIFO_DATA, - cf->data, DIV_ROUND_UP(cf->len, 4)); + cf->data, len_padded); if (err) goto out_fail; @@ -1732,15 +1739,15 @@ static netdev_tx_t m_can_tx_handler(struct m_can_classdev *cdev) fdflags |= TX_BUF_BRS; } - fifo_header.dlc = FIELD_PREP(TX_BUF_MM_MASK, putidx) | + fifo_element.dlc = FIELD_PREP(TX_BUF_MM_MASK, putidx) | FIELD_PREP(TX_BUF_DLC_MASK, can_fd_len2dlc(cf->len)) | fdflags | TX_BUF_EFC; - err = m_can_fifo_write(cdev, putidx, M_CAN_FIFO_ID, &fifo_header, 2); - if (err) - goto out_fail; - err = m_can_fifo_write(cdev, putidx, M_CAN_FIFO_DATA, - cf->data, DIV_ROUND_UP(cf->len, 4)); + memcpy_and_pad(fifo_element.data, CANFD_MAX_DLEN, &cf->data, + cf->len, 0); + + err = m_can_fifo_write(cdev, putidx, M_CAN_FIFO_ID, + &fifo_element, 2 + len_padded); if (err) goto out_fail; -- 2.43.0
