diff options
Diffstat (limited to 'drivers/net/can/spi/mcp251xfd/mcp251xfd-rx.c')
| -rw-r--r-- | drivers/net/can/spi/mcp251xfd/mcp251xfd-rx.c | 165 |
1 files changed, 111 insertions, 54 deletions
diff --git a/drivers/net/can/spi/mcp251xfd/mcp251xfd-rx.c b/drivers/net/can/spi/mcp251xfd/mcp251xfd-rx.c index ced8d9c81f8c..fe897f3e4c12 100644 --- a/drivers/net/can/spi/mcp251xfd/mcp251xfd-rx.c +++ b/drivers/net/can/spi/mcp251xfd/mcp251xfd-rx.c @@ -2,7 +2,7 @@ // // mcp251xfd - Microchip MCP251xFD Family CAN controller driver // -// Copyright (c) 2019, 2020, 2021 Pengutronix, +// Copyright (c) 2019, 2020, 2021, 2023 Pengutronix, // Marc Kleine-Budde <kernel@pengutronix.de> // // Based on: @@ -16,23 +16,14 @@ #include "mcp251xfd.h" -static inline int -mcp251xfd_rx_head_get_from_chip(const struct mcp251xfd_priv *priv, - const struct mcp251xfd_rx_ring *ring, - u8 *rx_head, bool *fifo_empty) +static inline bool mcp251xfd_rx_fifo_sta_empty(const u32 fifo_sta) { - u32 fifo_sta; - int err; - - err = regmap_read(priv->map_reg, MCP251XFD_REG_FIFOSTA(ring->fifo_nr), - &fifo_sta); - if (err) - return err; - - *rx_head = FIELD_GET(MCP251XFD_REG_FIFOSTA_FIFOCI_MASK, fifo_sta); - *fifo_empty = !(fifo_sta & MCP251XFD_REG_FIFOSTA_TFNRFNIF); + return !(fifo_sta & MCP251XFD_REG_FIFOSTA_TFNRFNIF); +} - return 0; +static inline bool mcp251xfd_rx_fifo_sta_full(const u32 fifo_sta) +{ + return fifo_sta & MCP251XFD_REG_FIFOSTA_TFERFFIF; } static inline int @@ -80,29 +71,49 @@ mcp251xfd_check_rx_tail(const struct mcp251xfd_priv *priv, } static int -mcp251xfd_rx_ring_update(const struct mcp251xfd_priv *priv, - struct mcp251xfd_rx_ring *ring) +mcp251xfd_get_rx_len(const struct mcp251xfd_priv *priv, + const struct mcp251xfd_rx_ring *ring, + u8 *len_p) { - u32 new_head; - u8 chip_rx_head; - bool fifo_empty; + const u8 shift = ring->obj_num_shift_to_u8; + u8 chip_head, tail, len; + u32 fifo_sta; int err; - err = mcp251xfd_rx_head_get_from_chip(priv, ring, &chip_rx_head, - &fifo_empty); - if (err || fifo_empty) + err = regmap_read(priv->map_reg, MCP251XFD_REG_FIFOSTA(ring->fifo_nr), + &fifo_sta); + if (err) + return err; + + if (mcp251xfd_rx_fifo_sta_empty(fifo_sta)) { + *len_p = 0; + return 0; + } + + if (mcp251xfd_rx_fifo_sta_full(fifo_sta)) { + *len_p = ring->obj_num; + return 0; + } + + chip_head = FIELD_GET(MCP251XFD_REG_FIFOSTA_FIFOCI_MASK, fifo_sta); + + err = mcp251xfd_check_rx_tail(priv, ring); + if (err) return err; + tail = mcp251xfd_get_rx_tail(ring); - /* chip_rx_head, is the next RX-Object filled by the HW. - * The new RX head must be >= the old head. + /* First shift to full u8. The subtraction works on signed + * values, that keeps the difference steady around the u8 + * overflow. The right shift acts on len, which is an u8. */ - new_head = round_down(ring->head, ring->obj_num) + chip_rx_head; - if (new_head <= ring->head) - new_head += ring->obj_num; + BUILD_BUG_ON(sizeof(ring->obj_num) != sizeof(chip_head)); + BUILD_BUG_ON(sizeof(ring->obj_num) != sizeof(tail)); + BUILD_BUG_ON(sizeof(ring->obj_num) != sizeof(len)); - ring->head = new_head; + len = (chip_head << shift) - (tail << shift); + *len_p = len >> shift; - return mcp251xfd_check_rx_tail(priv, ring); + return 0; } static void @@ -148,8 +159,6 @@ mcp251xfd_hw_rx_obj_to_skb(const struct mcp251xfd_priv *priv, if (!(hw_rx_obj->flags & MCP251XFD_OBJ_FLAGS_RTR)) memcpy(cfd->data, hw_rx_obj->data, cfd->len); - - mcp251xfd_skb_set_timestamp(priv, skb, hw_rx_obj->ts); } static int @@ -160,8 +169,26 @@ mcp251xfd_handle_rxif_one(struct mcp251xfd_priv *priv, struct net_device_stats *stats = &priv->ndev->stats; struct sk_buff *skb; struct canfd_frame *cfd; + u64 timestamp; int err; + /* According to mcp2518fd erratum DS80000789E 6. the FIFOCI + * bits of a FIFOSTA register, here the RX FIFO head index + * might be corrupted and we might process past the RX FIFO's + * head into old CAN frames. + * + * Compare the timestamp of currently processed CAN frame with + * last valid frame received. Abort with -EBADMSG if an old + * CAN frame is detected. + */ + timestamp = timecounter_cyc2time(&priv->tc, hw_rx_obj->ts); + if (timestamp <= ring->last_valid) { + stats->rx_fifo_errors++; + + return -EBADMSG; + } + ring->last_valid = timestamp; + if (hw_rx_obj->flags & MCP251XFD_OBJ_FLAGS_FDF) skb = alloc_canfd_skb(priv->ndev, &cfd); else @@ -172,6 +199,7 @@ mcp251xfd_handle_rxif_one(struct mcp251xfd_priv *priv, return 0; } + mcp251xfd_skb_set_timestamp(skb, timestamp); mcp251xfd_hw_rx_obj_to_skb(priv, hw_rx_obj, skb); err = can_rx_offload_queue_timestamp(&priv->offload, skb, hw_rx_obj->ts); if (err) @@ -198,51 +226,80 @@ mcp251xfd_rx_obj_read(const struct mcp251xfd_priv *priv, } static int +mcp251xfd_handle_rxif_ring_uinc(const struct mcp251xfd_priv *priv, + struct mcp251xfd_rx_ring *ring, + u8 len) +{ + int offset; + int err; + + if (!len) + return 0; + + ring->head += len; + + /* Increment the RX FIFO tail pointer 'len' times in a + * single SPI message. + * + * Note: + * Calculate offset, so that the SPI transfer ends on + * the last message of the uinc_xfer array, which has + * "cs_change == 0", to properly deactivate the chip + * select. + */ + offset = ARRAY_SIZE(ring->uinc_xfer) - len; + err = spi_sync_transfer(priv->spi, + ring->uinc_xfer + offset, len); + if (err) + return err; + + ring->tail += len; + + return 0; +} + +static int mcp251xfd_handle_rxif_ring(struct mcp251xfd_priv *priv, struct mcp251xfd_rx_ring *ring) { struct mcp251xfd_hw_rx_obj_canfd *hw_rx_obj = ring->obj; - u8 rx_tail, len; + u8 rx_tail, len, l; int err, i; - err = mcp251xfd_rx_ring_update(priv, ring); + err = mcp251xfd_get_rx_len(priv, ring, &len); if (err) return err; - while ((len = mcp251xfd_get_rx_linear_len(ring))) { - int offset; - + while ((l = mcp251xfd_get_rx_linear_len(ring, len))) { rx_tail = mcp251xfd_get_rx_tail(ring); err = mcp251xfd_rx_obj_read(priv, ring, hw_rx_obj, - rx_tail, len); + rx_tail, l); if (err) return err; - for (i = 0; i < len; i++) { + for (i = 0; i < l; i++) { err = mcp251xfd_handle_rxif_one(priv, ring, (void *)hw_rx_obj + i * ring->obj_size); - if (err) + + /* -EBADMSG means we're affected by mcp2518fd + * erratum DS80000789E 6., i.e. the timestamp + * in the RX object is older that the last + * valid received CAN frame. Don't process any + * further and mark processed frames as good. + */ + if (err == -EBADMSG) + return mcp251xfd_handle_rxif_ring_uinc(priv, ring, i); + else if (err) return err; } - /* Increment the RX FIFO tail pointer 'len' times in a - * single SPI message. - * - * Note: - * Calculate offset, so that the SPI transfer ends on - * the last message of the uinc_xfer array, which has - * "cs_change == 0", to properly deactivate the chip - * select. - */ - offset = ARRAY_SIZE(ring->uinc_xfer) - len; - err = spi_sync_transfer(priv->spi, - ring->uinc_xfer + offset, len); + err = mcp251xfd_handle_rxif_ring_uinc(priv, ring, l); if (err) return err; - ring->tail += len; + len -= l; } return 0; |