Combine header and data before writing to the transmit fifo to reduce
the overhead for peripheral chips.
Signed-off-by: Markus Schneider-Pargmann <[email protected]>
Reviewed-by: Simon Horman <[email protected]>
---
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