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can: m_can: Write transmit header and data in one transaction

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Combine header and data before writing to the transmit fifo to reduce
the overhead for peripheral chips.

Signed-off-by: Markus Schneider-Pargmann <msp@baylibre.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Link: https://lore.kernel.org/all/20240207093220.2681425-4-msp@baylibre.com
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
This commit is contained in:
Markus Schneider-Pargmann
2024-02-07 10:32:09 +01:00
committed by Marc Kleine-Budde
parent ba72f6c78b
commit 4248ba9ea2
1 changed files with 21 additions and 14 deletions
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35
drivers/net/can/m_can/m_can.c
View File

@@ -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;