Commit 2f1a01a8 authored by Marc Kleine-Budde's avatar Marc Kleine-Budde
Browse files

can: at91_can: rename struct at91_priv::{tx_next,tx_echo} to {tx_head,tx_tail} 

To increase code readability, use the same naming of the counters for
the TX FIFO as in the other drivers implementing the same algorithm.

Link: https://lore.kernel.org/all/20231005-at91_can-rx_offload-v2-12-9987d53600e0@pengutronix.de


Signed-off-by: default avatarMarc Kleine-Budde <mkl@pengutronix.de>
parent 2b08e521

drivers/net/can/at91_can.c

+28 −28
Original line number Diff line number Diff line
@@ -154,8 +154,8 @@ struct at91_priv { 
	void __iomem *reg_base;



	u32 reg_sr;

	unsigned int tx_next;

	unsigned int tx_echo;

	unsigned int tx_head;

	unsigned int tx_tail;

	unsigned int rx_next;

	struct at91_devtype_data devtype_data;
@@ -253,24 +253,24 @@ static inline unsigned int get_mb_tx_last(const struct at91_priv *priv) 
	return get_mb_tx_first(priv) + get_mb_tx_num(priv) - 1;

}



static inline unsigned int get_next_prio_shift(const struct at91_priv *priv)

static inline unsigned int get_head_prio_shift(const struct at91_priv *priv)

{

	return get_mb_tx_shift(priv);

}



static inline unsigned int get_next_prio_mask(const struct at91_priv *priv)

static inline unsigned int get_head_prio_mask(const struct at91_priv *priv)

{

	return 0xf << get_mb_tx_shift(priv);

}



static inline unsigned int get_next_mb_mask(const struct at91_priv *priv)

static inline unsigned int get_head_mb_mask(const struct at91_priv *priv)

{

	return AT91_MB_MASK(get_mb_tx_shift(priv));

}



static inline unsigned int get_next_mask(const struct at91_priv *priv)

static inline unsigned int get_head_mask(const struct at91_priv *priv)

{

	return get_next_mb_mask(priv) | get_next_prio_mask(priv);

	return get_head_mb_mask(priv) | get_head_prio_mask(priv);

}



static inline unsigned int get_irq_mb_rx(const struct at91_priv *priv)
@@ -285,19 +285,19 @@ static inline unsigned int get_irq_mb_tx(const struct at91_priv *priv) 
		~AT91_MB_MASK(get_mb_tx_first(priv));

}



static inline unsigned int get_tx_next_mb(const struct at91_priv *priv)

static inline unsigned int get_tx_head_mb(const struct at91_priv *priv)

{

	return (priv->tx_next & get_next_mb_mask(priv)) + get_mb_tx_first(priv);

	return (priv->tx_head & get_head_mb_mask(priv)) + get_mb_tx_first(priv);

}



static inline unsigned int get_tx_next_prio(const struct at91_priv *priv)

static inline unsigned int get_tx_head_prio(const struct at91_priv *priv)

{

	return (priv->tx_next >> get_next_prio_shift(priv)) & 0xf;

	return (priv->tx_head >> get_head_prio_shift(priv)) & 0xf;

}



static inline unsigned int get_tx_echo_mb(const struct at91_priv *priv)

static inline unsigned int get_tx_tail_mb(const struct at91_priv *priv)

{

	return (priv->tx_echo & get_next_mb_mask(priv)) + get_mb_tx_first(priv);

	return (priv->tx_tail & get_head_mb_mask(priv)) + get_mb_tx_first(priv);

}



static inline u32 at91_read(const struct at91_priv *priv, enum at91_reg reg)
@@ -374,7 +374,7 @@ static void at91_setup_mailboxes(struct net_device *dev) 
		set_mb_mode_prio(priv, i, AT91_MB_MODE_TX, 0);



	/* Reset tx and rx helper pointers */

	priv->tx_next = priv->tx_echo = 0;

	priv->tx_head = priv->tx_tail = 0;

	priv->rx_next = get_mb_rx_first(priv);

}
@@ -470,11 +470,11 @@ static void at91_chip_stop(struct net_device *dev, enum can_state state) 
 * stop sending, waiting for all messages to be delivered, then start

 * again with mailbox AT91_MB_TX_FIRST prio 0.

 *

 * We use the priv->tx_next as counter for the next transmission

 * We use the priv->tx_head as counter for the next transmission

 * mailbox, but without the offset AT91_MB_TX_FIRST. The lower bits

 * encode the mailbox number, the upper 4 bits the mailbox priority:

 *

 * priv->tx_next = (prio << get_next_prio_shift(priv)) |

 * priv->tx_head = (prio << get_next_prio_shift(priv)) |

 *                 (mb - get_mb_tx_first(priv));

 *

 */
@@ -488,8 +488,8 @@ static netdev_tx_t at91_start_xmit(struct sk_buff *skb, struct net_device *dev) 
	if (can_dev_dropped_skb(dev, skb))

		return NETDEV_TX_OK;



	mb = get_tx_next_mb(priv);

	prio = get_tx_next_prio(priv);

	mb = get_tx_head_mb(priv);

	prio = get_tx_head_prio(priv);



	if (unlikely(!(at91_read(priv, AT91_MSR(mb)) & AT91_MSR_MRDY))) {

		netif_stop_queue(dev);
@@ -521,15 +521,15 @@ static netdev_tx_t at91_start_xmit(struct sk_buff *skb, struct net_device *dev) 


	/* we have to stop the queue and deliver all messages in case

	 * of a prio+mb counter wrap around. This is the case if

	 * tx_next buffer prio and mailbox equals 0.

	 * tx_head buffer prio and mailbox equals 0.

	 *

	 * also stop the queue if next buffer is still in use

	 * (== not ready)

	 */

	priv->tx_next++;

	if (!(at91_read(priv, AT91_MSR(get_tx_next_mb(priv))) &

	priv->tx_head++;

	if (!(at91_read(priv, AT91_MSR(get_tx_head_mb(priv))) &

	      AT91_MSR_MRDY) ||

	    (priv->tx_next & get_next_mask(priv)) == 0)

	    (priv->tx_head & get_head_mask(priv)) == 0)

		netif_stop_queue(dev);



	/* Enable interrupt for this mailbox */
@@ -849,11 +849,11 @@ static int at91_poll(struct napi_struct *napi, int quota) 


/* theory of operation:

 *

 * priv->tx_echo holds the number of the oldest can_frame put for

 * priv->tx_tail holds the number of the oldest can_frame put for

 * transmission into the hardware, but not yet ACKed by the CAN tx

 * complete IRQ.

 *

 * We iterate from priv->tx_echo to priv->tx_next and check if the

 * We iterate from priv->tx_tail to priv->tx_head and check if the

 * packet has been transmitted, echo it back to the CAN framework. If

 * we discover a not yet transmitted package, stop looking for more.

 *
@@ -866,8 +866,8 @@ static void at91_irq_tx(struct net_device *dev, u32 reg_sr) 


	/* masking of reg_sr not needed, already done by at91_irq */



	for (/* nix */; (priv->tx_next - priv->tx_echo) > 0; priv->tx_echo++) {

		mb = get_tx_echo_mb(priv);

	for (/* nix */; (priv->tx_head - priv->tx_tail) > 0; priv->tx_tail++) {

		mb = get_tx_tail_mb(priv);



		/* no event in mailbox? */

		if (!(reg_sr & (1 << mb)))
@@ -896,8 +896,8 @@ static void at91_irq_tx(struct net_device *dev, u32 reg_sr) 
	 * we get a TX int for the last can frame directly before a

	 * wrap around.

	 */

	if ((priv->tx_next & get_next_mask(priv)) != 0 ||

	    (priv->tx_echo & get_next_mask(priv)) == 0)

	if ((priv->tx_head & get_head_mask(priv)) != 0 ||

	    (priv->tx_tail & get_head_mask(priv)) == 0)

		netif_wake_queue(dev);

}