// SPDX-License-Identifier: GPL-2.0
//
// Copyright (c) 2023, 2024 Pengutronix,
// Marc Kleine-Budde <[email protected]>
//
#include <net/netdev_queues.h>
#include "rockchip_canfd.h"
static bool rkcanfd_can_frame_header_equal(const struct canfd_frame *const cfd1,
const struct canfd_frame *const cfd2,
const bool is_canfd)
{
const u8 mask_flags = CANFD_BRS | CANFD_ESI | CANFD_FDF;
canid_t mask = CAN_EFF_FLAG;
if (canfd_sanitize_len(cfd1->len) != canfd_sanitize_len(cfd2->len))
return false;
if (!is_canfd)
mask |= CAN_RTR_FLAG;
if (cfd1->can_id & CAN_EFF_FLAG)
mask |= CAN_EFF_MASK;
else
mask |= CAN_SFF_MASK;
if ((cfd1->can_id & mask) != (cfd2->can_id & mask))
return false;
if (is_canfd &&
(cfd1->flags & mask_flags) != (cfd2->flags & mask_flags))
return false;
return true;
}
static bool rkcanfd_can_frame_data_equal(const struct canfd_frame *cfd1,
const struct canfd_frame *cfd2,
const bool is_canfd)
{
u8 len;
if (!is_canfd && (cfd1->can_id & CAN_RTR_FLAG))
return true;
len = canfd_sanitize_len(cfd1->len);
return !memcmp(cfd1->data, cfd2->data, len);
}
static unsigned int
rkcanfd_fifo_header_to_cfd_header(const struct rkcanfd_priv *priv,
const struct rkcanfd_fifo_header *header,
struct canfd_frame *cfd)
{
unsigned int len = sizeof(*cfd) - sizeof(cfd->data);
u8 dlc;
if (header->frameinfo & RKCANFD_REG_FD_FRAMEINFO_FRAME_FORMAT)
cfd->can_id = FIELD_GET(RKCANFD_REG_FD_ID_EFF, header->id) |
CAN_EFF_FLAG;
else
cfd->can_id = FIELD_GET(RKCANFD_REG_FD_ID_SFF, header->id);
dlc = FIELD_GET(RKCANFD_REG_FD_FRAMEINFO_DATA_LENGTH,
header->frameinfo);
/* CAN-FD */
if (header->frameinfo & RKCANFD_REG_FD_FRAMEINFO_FDF) {
cfd->len = can_fd_dlc2len(dlc);
/* The cfd is not allocated by alloc_canfd_skb(), so
* set CANFD_FDF here.
*/
cfd->flags |= CANFD_FDF;
if (header->frameinfo & RKCANFD_REG_FD_FRAMEINFO_BRS)
cfd->flags |= CANFD_BRS;
} else {
cfd->len = can_cc_dlc2len(dlc);
if (header->frameinfo & RKCANFD_REG_FD_FRAMEINFO_RTR) {
cfd->can_id |= CAN_RTR_FLAG;
return len;
}
}
return len + cfd->len;
}
static int rkcanfd_rxstx_filter(struct rkcanfd_priv *priv,
const struct canfd_frame *cfd_rx, const u32 ts,
bool *tx_done)
{
struct net_device_stats *stats = &priv->ndev->stats;
struct rkcanfd_stats *rkcanfd_stats = &priv->stats;
const struct canfd_frame *cfd_nominal;
const struct sk_buff *skb;
unsigned int tx_tail;
tx_tail = rkcanfd_get_tx_tail(priv);
skb = priv->can.echo_skb[tx_tail];
if (!skb) {
netdev_err(priv->ndev,
"%s: echo_skb[%u]=NULL tx_head=0x%08x tx_tail=0x%08x\n",
__func__, tx_tail,
priv->tx_head, priv->tx_tail);
return -ENOMSG;
}
cfd_nominal = (struct canfd_frame *)skb->data;
/* We RX'ed a frame identical to our pending TX frame. */
if (rkcanfd_can_frame_header_equal(cfd_rx, cfd_nominal,
cfd_rx->flags & CANFD_FDF) &&
rkcanfd_can_frame_data_equal(cfd_rx, cfd_nominal,
cfd_rx->flags & CANFD_FDF)) {
unsigned int frame_len;
rkcanfd_handle_tx_done_one(priv, ts, &frame_len);
WRITE_ONCE(priv->tx_tail, priv->tx_tail + 1);
netif_subqueue_completed_wake(priv->ndev, 0, 1, frame_len,
rkcanfd_get_effective_tx_free(priv),
RKCANFD_TX_START_THRESHOLD);
*tx_done = true;
return 0;
}
if (!(priv->devtype_data.quirks & RKCANFD_QUIRK_RK3568_ERRATUM_6))
return 0;
/* Erratum 6: Extended frames may be send as standard frames.
*
* Not affected if:
* - TX'ed a standard frame -or-
* - RX'ed an extended frame
*/
if (!(cfd_nominal->can_id & CAN_EFF_FLAG) ||
(cfd_rx->can_id & CAN_EFF_FLAG))
return 0;
/* Not affected if:
* - standard part and RTR flag of the TX'ed frame
* is not equal the CAN-ID and RTR flag of the RX'ed frame.
*/
if ((cfd_nominal->can_id & (CAN_RTR_FLAG | CAN_SFF_MASK)) !=
(cfd_rx->can_id & (CAN_RTR_FLAG | CAN_SFF_MASK)))
return 0;
/* Not affected if:
* - length is not the same
*/
if (cfd_nominal->len != cfd_rx->len)
return 0;
/* Not affected if:
* - the data of non RTR frames is different
*/
if (!(cfd_nominal->can_id & CAN_RTR_FLAG) &&
memcmp(cfd_nominal->data, cfd_rx->data, cfd_nominal->len))
return 0;
/* Affected by Erratum 6 */
u64_stats_update_begin(&rkcanfd_stats->syncp);
u64_stats_inc(&rkcanfd_stats->tx_extended_as_standard_errors);
u64_stats_update_end(&rkcanfd_stats->syncp);
/* Manual handling of CAN Bus Error counters. See
* rkcanfd_get_corrected_berr_counter() for detailed
* explanation.
*/
if (priv->bec.txerr)
priv->bec.txerr--;
*tx_done = true;
stats->tx_packets++;
stats->tx_errors++;
rkcanfd_xmit_retry(priv);
return 0;
}
static inline bool
rkcanfd_fifo_header_empty(const struct rkcanfd_fifo_header *header)
{
/* Erratum 5: If the FIFO is empty, we read the same value for
* all elements.
*/
return header->frameinfo == header->id &&
header->frameinfo == header->ts;
}
static int rkcanfd_handle_rx_int_one(struct rkcanfd_priv *priv)
{
struct net_device_stats *stats = &priv->ndev->stats;
struct canfd_frame cfd[1] = { }, *skb_cfd;
struct rkcanfd_fifo_header header[1] = { };
struct sk_buff *skb;
unsigned int len;
int err;
/* read header into separate struct and convert it later */
rkcanfd_read_rep(priv, RKCANFD_REG_RX_FIFO_RDATA,
header, sizeof(*header));
/* read data directly into cfd */
rkcanfd_read_rep(priv, RKCANFD_REG_RX_FIFO_RDATA,
cfd->data, sizeof(cfd->data));
/* Erratum 5: Counters for TXEFIFO and RXFIFO may be wrong */
if (rkcanfd_fifo_header_empty(header)) {
struct rkcanfd_stats *rkcanfd_stats = &priv->stats;
u64_stats_update_begin(&rkcanfd_stats->syncp);
u64_stats_inc(&rkcanfd_stats->rx_fifo_empty_errors);
u64_stats_update_end(&rkcanfd_stats->syncp);
return 0;
}
len = rkcanfd_fifo_header_to_cfd_header(priv, header, cfd);
/* Drop any received CAN-FD frames if CAN-FD mode is not
* requested.
*/
if (header->frameinfo & RKCANFD_REG_FD_FRAMEINFO_FDF &&
!(priv->can.ctrlmode & CAN_CTRLMODE_FD)) {
stats->rx_dropped++;
return 0;
}
if (rkcanfd_get_tx_pending(priv)) {
bool tx_done = false;
err = rkcanfd_rxstx_filter(priv, cfd, header->ts, &tx_done);
if (err)
return err;
if (tx_done && !(priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK))
return 0;
}
/* Manual handling of CAN Bus Error counters. See
* rkcanfd_get_corrected_berr_counter() for detailed
* explanation.
*/
if (priv->bec.rxerr)
priv->bec.rxerr = min(CAN_ERROR_PASSIVE_THRESHOLD,
priv->bec.rxerr) - 1;
if (header->frameinfo & RKCANFD_REG_FD_FRAMEINFO_FDF)
skb = alloc_canfd_skb(priv->ndev, &skb_cfd);
else
skb = alloc_can_skb(priv->ndev, (struct can_frame **)&skb_cfd);
if (!skb) {
stats->rx_dropped++;
return 0;
}
memcpy(skb_cfd, cfd, len);
rkcanfd_skb_set_timestamp(priv, skb, header->ts);
err = can_rx_offload_queue_timestamp(&priv->offload, skb, header->ts);
if (err)
stats->rx_fifo_errors++;
return 0;
}
static inline unsigned int
rkcanfd_rx_fifo_get_len(const struct rkcanfd_priv *priv)
{
const u32 reg = rkcanfd_read(priv, RKCANFD_REG_RX_FIFO_CTRL);
return FIELD_GET(RKCANFD_REG_RX_FIFO_CTRL_RX_FIFO_CNT, reg);
}
int rkcanfd_handle_rx_int(struct rkcanfd_priv *priv)
{
unsigned int len;
int err;
while ((len = rkcanfd_rx_fifo_get_len(priv))) {
err = rkcanfd_handle_rx_int_one(priv);
if (err)
return err;
}
return 0;
}
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