Commit 1c0544d2 authored by Edward Cree's avatar Edward Cree Committed by Jakub Kicinski
Browse files

sfc: add and use efx_tx_send_pending in tx.c 



Instead of using efx_tx_queue_partner(), which relies on the assumption
 that tx_queues_per_channel is 2, efx_tx_send_pending() iterates over
 txqs with efx_for_each_channel_tx_queue().
We unconditionally set tx_queue->xmit_pending (renamed from
 xmit_more_available), then condition on xmit_more for the call to
 efx_tx_send_pending(), which will clear xmit_pending.  Thus, after an
 xmit_more TX, the doorbell is un-rung and xmit_pending is true.

Signed-off-by: default avatarEdward Cree <ecree@solarflare.com>
Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 44a8c4f3

drivers/net/ethernet/sfc/ef10.c

+1 −1
Original line number Diff line number Diff line
@@ -2367,7 +2367,7 @@ static void efx_ef10_tx_write(struct efx_tx_queue *tx_queue) 
	unsigned int write_ptr;

	efx_qword_t *txd;



	tx_queue->xmit_more_available = false;

	tx_queue->xmit_pending = false;

	if (unlikely(tx_queue->write_count == tx_queue->insert_count))

		return;

drivers/net/ethernet/sfc/ef100_tx.c

+7 −7
Original line number Diff line number Diff line
@@ -131,7 +131,7 @@ void ef100_notify_tx_desc(struct efx_tx_queue *tx_queue) 
	efx_writed_page(tx_queue->efx, &reg,

			ER_GZ_TX_RING_DOORBELL, tx_queue->queue);

	tx_queue->notify_count = tx_queue->write_count;

	tx_queue->xmit_more_available = false;

	tx_queue->xmit_pending = false;

}



static void ef100_tx_push_buffers(struct efx_tx_queue *tx_queue)
@@ -373,14 +373,14 @@ int ef100_enqueue_skb(struct efx_tx_queue *tx_queue, struct sk_buff *skb) 
	}



	if (__netdev_tx_sent_queue(tx_queue->core_txq, skb->len, xmit_more))

		tx_queue->xmit_more_available = false; /* push doorbell */

		tx_queue->xmit_pending = false; /* push doorbell */

	else if (tx_queue->write_count - tx_queue->notify_count > 255)

		/* Ensure we never push more than 256 packets at once */

		tx_queue->xmit_more_available = false; /* push */

		tx_queue->xmit_pending = false; /* push */

	else

		tx_queue->xmit_more_available = true; /* don't push yet */

		tx_queue->xmit_pending = true; /* don't push yet */



	if (!tx_queue->xmit_more_available)

	if (!tx_queue->xmit_pending)

		ef100_tx_push_buffers(tx_queue);



	if (segments) {
@@ -400,9 +400,9 @@ err: 
	/* If we're not expecting another transmit and we had something to push

	 * on this queue then we need to push here to get the previous packets

	 * out.  We only enter this branch from before the 'Update BQL' section

	 * above, so xmit_more_available still refers to the old state.

	 * above, so xmit_pending still refers to the old state.

	 */

	if (tx_queue->xmit_more_available && !xmit_more)

	if (tx_queue->xmit_pending && !xmit_more)

		ef100_tx_push_buffers(tx_queue);

	return rc;

}

drivers/net/ethernet/sfc/farch.c

+1 −1
Original line number Diff line number Diff line
@@ -320,7 +320,7 @@ void efx_farch_tx_write(struct efx_tx_queue *tx_queue) 
	unsigned write_ptr;

	unsigned old_write_count = tx_queue->write_count;



	tx_queue->xmit_more_available = false;

	tx_queue->xmit_pending = false;

	if (unlikely(tx_queue->write_count == tx_queue->insert_count))

		return;

drivers/net/ethernet/sfc/net_driver.h

+2 −2
Original line number Diff line number Diff line
@@ -244,7 +244,7 @@ struct efx_tx_buffer { 
 * @tso_fallbacks: Number of times TSO fallback used

 * @pushes: Number of times the TX push feature has been used

 * @pio_packets: Number of times the TX PIO feature has been used

 * @xmit_more_available: Are any packets waiting to be pushed to the NIC

 * @xmit_pending: Are any packets waiting to be pushed to the NIC

 * @cb_packets: Number of times the TX copybreak feature has been used

 * @notify_count: Count of notified descriptors to the NIC

 * @empty_read_count: If the completion path has seen the queue as empty
@@ -292,7 +292,7 @@ struct efx_tx_queue { 
	unsigned int tso_fallbacks;

	unsigned int pushes;

	unsigned int pio_packets;

	bool xmit_more_available;

	bool xmit_pending;

	unsigned int cb_packets;

	unsigned int notify_count;

	/* Statistics to supplement MAC stats */

drivers/net/ethernet/sfc/tx.c

+31 −28
Original line number Diff line number Diff line
@@ -268,6 +268,19 @@ static int efx_enqueue_skb_pio(struct efx_tx_queue *tx_queue, 
}

#endif /* EFX_USE_PIO */



/* Send any pending traffic for a channel. xmit_more is shared across all

 * queues for a channel, so we must check all of them.

 */

static void efx_tx_send_pending(struct efx_channel *channel)

{

	struct efx_tx_queue *q;



	efx_for_each_channel_tx_queue(q, channel) {

		if (q->xmit_pending)

			efx_nic_push_buffers(q);

	}

}



/*

 * Add a socket buffer to a TX queue

 *
@@ -336,21 +349,11 @@ netdev_tx_t __efx_enqueue_skb(struct efx_tx_queue *tx_queue, struct sk_buff *skb 


	efx_tx_maybe_stop_queue(tx_queue);



	/* Pass off to hardware */

	if (__netdev_tx_sent_queue(tx_queue->core_txq, skb_len, xmit_more)) {

		struct efx_tx_queue *txq2 = efx_tx_queue_partner(tx_queue);



		/* There could be packets left on the partner queue if

		 * xmit_more was set. If we do not push those they

		 * could be left for a long time and cause a netdev watchdog.

		 */

		if (txq2->xmit_more_available)

			efx_nic_push_buffers(txq2);

	tx_queue->xmit_pending = true;



		efx_nic_push_buffers(tx_queue);

	} else {

		tx_queue->xmit_more_available = xmit_more;

	}

	/* Pass off to hardware */

	if (__netdev_tx_sent_queue(tx_queue->core_txq, skb_len, xmit_more))

		efx_tx_send_pending(tx_queue->channel);



	if (segments) {

		tx_queue->tso_bursts++;
@@ -371,14 +374,8 @@ err: 
	 * on this queue or a partner queue then we need to push here to get the

	 * previous packets out.

	 */

	if (!xmit_more) {

		struct efx_tx_queue *txq2 = efx_tx_queue_partner(tx_queue);



		if (txq2->xmit_more_available)

			efx_nic_push_buffers(txq2);



		efx_nic_push_buffers(tx_queue);

	}

	if (!xmit_more)

		efx_tx_send_pending(tx_queue->channel);



	return NETDEV_TX_OK;

}
@@ -489,18 +486,24 @@ netdev_tx_t efx_hard_start_xmit(struct sk_buff *skb, 


	EFX_WARN_ON_PARANOID(!netif_device_present(net_dev));



	/* PTP "event" packet */

	if (unlikely(efx_xmit_with_hwtstamp(skb)) &&

	    unlikely(efx_ptp_is_ptp_tx(efx, skb))) {

		return efx_ptp_tx(efx, skb);

	}



	index = skb_get_queue_mapping(skb);

	type = skb->ip_summed == CHECKSUM_PARTIAL ? EFX_TXQ_TYPE_OFFLOAD : 0;

	if (index >= efx->n_tx_channels) {

		index -= efx->n_tx_channels;

		type |= EFX_TXQ_TYPE_HIGHPRI;

	}



	/* PTP "event" packet */

	if (unlikely(efx_xmit_with_hwtstamp(skb)) &&

	    unlikely(efx_ptp_is_ptp_tx(efx, skb))) {

		/* There may be existing transmits on the channel that are

		 * waiting for this packet to trigger the doorbell write.

		 * We need to send the packets at this point.

		 */

		efx_tx_send_pending(efx_get_tx_channel(efx, index));

		return efx_ptp_tx(efx, skb);

	}



	tx_queue = efx_get_tx_queue(efx, index, type);



	return __efx_enqueue_skb(tx_queue, skb);

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