Commit 02443ab8 authored by Edward Cree's avatar Edward Cree Committed by David S. Miller
Browse files

sfc: support passing a representor to the EF100 TX path 



A non-null efv in __ef100_enqueue_skb() indicates that the packet is
 from that representor, should be transmitted with a suitable option
 descriptor (to instruct the switch to deliver it to the representee),
 and should not be accounted to the parent PF's stats or BQL.

Signed-off-by: default avatarEdward Cree <ecree.xilinx@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent da56552d

drivers/net/ethernet/sfc/ef100_rep.h

+8 −0
Original line number Diff line number Diff line
@@ -15,6 +15,12 @@ 


#include "net_driver.h"



struct efx_rep_sw_stats {

	atomic64_t rx_packets, tx_packets;

	atomic64_t rx_bytes, tx_bytes;

	atomic64_t rx_dropped, tx_errors;

};



/**

 * struct efx_rep - Private data for an Efx representor

 *
@@ -24,6 +30,7 @@ 
 * @mport: m-port ID of corresponding VF

 * @idx: VF index

 * @list: entry on efx->vf_reps

 * @stats: software traffic counters for netdev stats

 */

struct efx_rep {

	struct efx_nic *parent;
@@ -32,6 +39,7 @@ struct efx_rep { 
	u32 mport;

	unsigned int idx;

	struct list_head list;

	struct efx_rep_sw_stats stats;

};



int efx_ef100_vfrep_create(struct efx_nic *efx, unsigned int i);

drivers/net/ethernet/sfc/ef100_tx.c

+80 −4
Original line number Diff line number Diff line
@@ -254,7 +254,8 @@ static void ef100_make_tso_desc(struct efx_nic *efx, 


static void ef100_tx_make_descriptors(struct efx_tx_queue *tx_queue,

				      const struct sk_buff *skb,

				      unsigned int segment_count)

				      unsigned int segment_count,

				      struct efx_rep *efv)

{

	unsigned int old_write_count = tx_queue->write_count;

	unsigned int new_write_count = old_write_count;
@@ -272,6 +273,20 @@ static void ef100_tx_make_descriptors(struct efx_tx_queue *tx_queue, 
	else

		next_desc_type = ESE_GZ_TX_DESC_TYPE_SEND;



	if (unlikely(efv)) {

		/* Create TX override descriptor */

		write_ptr = new_write_count & tx_queue->ptr_mask;

		txd = ef100_tx_desc(tx_queue, write_ptr);

		++new_write_count;



		tx_queue->packet_write_count = new_write_count;

		EFX_POPULATE_OWORD_3(*txd,

				     ESF_GZ_TX_DESC_TYPE, ESE_GZ_TX_DESC_TYPE_PREFIX,

				     ESF_GZ_TX_PREFIX_EGRESS_MPORT, efv->mport,

				     ESF_GZ_TX_PREFIX_EGRESS_MPORT_EN, 1);

		nr_descs--;

	}



	/* if it's a raw write (such as XDP) then always SEND single frames */

	if (!skb)

		nr_descs = 1;
@@ -306,6 +321,9 @@ static void ef100_tx_make_descriptors(struct efx_tx_queue *tx_queue, 
		/* if it's a raw write (such as XDP) then always SEND */

		next_desc_type = skb ? ESE_GZ_TX_DESC_TYPE_SEG :

				       ESE_GZ_TX_DESC_TYPE_SEND;

		/* mark as an EFV buffer if applicable */

		if (unlikely(efv))

			buffer->flags |= EFX_TX_BUF_EFV;



	} while (new_write_count != tx_queue->insert_count);
@@ -324,7 +342,7 @@ static void ef100_tx_make_descriptors(struct efx_tx_queue *tx_queue, 


void ef100_tx_write(struct efx_tx_queue *tx_queue)

{

	ef100_tx_make_descriptors(tx_queue, NULL, 0);

	ef100_tx_make_descriptors(tx_queue, NULL, 0, NULL);

	ef100_tx_push_buffers(tx_queue);

}
@@ -350,6 +368,12 @@ void ef100_ev_tx(struct efx_channel *channel, const efx_qword_t *p_event) 
 * function will free the SKB.

 */

int ef100_enqueue_skb(struct efx_tx_queue *tx_queue, struct sk_buff *skb)

{

	return __ef100_enqueue_skb(tx_queue, skb, NULL);

}



int __ef100_enqueue_skb(struct efx_tx_queue *tx_queue, struct sk_buff *skb,

			struct efx_rep *efv)

{

	unsigned int old_insert_count = tx_queue->insert_count;

	struct efx_nic *efx = tx_queue->efx;
@@ -376,16 +400,64 @@ int ef100_enqueue_skb(struct efx_tx_queue *tx_queue, struct sk_buff *skb) 
			return 0;

	}



	if (unlikely(efv)) {

		struct efx_tx_buffer *buffer = __efx_tx_queue_get_insert_buffer(tx_queue);



		/* Drop representor packets if the queue is stopped.

		 * We currently don't assert backoff to representors so this is

		 * to make sure representor traffic can't starve the main

		 * net device.

		 * And, of course, if there are no TX descriptors left.

		 */

		if (netif_tx_queue_stopped(tx_queue->core_txq) ||

		    unlikely(efx_tx_buffer_in_use(buffer))) {

			atomic64_inc(&efv->stats.tx_errors);

			rc = -ENOSPC;

			goto err;

		}



		/* Also drop representor traffic if it could cause us to

		 * stop the queue. If we assert backoff and we haven't

		 * received traffic on the main net device recently then the

		 * TX watchdog can go off erroneously.

		 */

		fill_level = efx_channel_tx_old_fill_level(tx_queue->channel);

		fill_level += efx_tx_max_skb_descs(efx);

		if (fill_level > efx->txq_stop_thresh) {

			struct efx_tx_queue *txq2;



			/* Refresh cached fill level and re-check */

			efx_for_each_channel_tx_queue(txq2, tx_queue->channel)

				txq2->old_read_count = READ_ONCE(txq2->read_count);



			fill_level = efx_channel_tx_old_fill_level(tx_queue->channel);

			fill_level += efx_tx_max_skb_descs(efx);

			if (fill_level > efx->txq_stop_thresh) {

				atomic64_inc(&efv->stats.tx_errors);

				rc = -ENOSPC;

				goto err;

			}

		}



		buffer->flags = EFX_TX_BUF_OPTION | EFX_TX_BUF_EFV;

		tx_queue->insert_count++;

	}



	/* Map for DMA and create descriptors */

	rc = efx_tx_map_data(tx_queue, skb, segments);

	if (rc)

		goto err;

	ef100_tx_make_descriptors(tx_queue, skb, segments);

	ef100_tx_make_descriptors(tx_queue, skb, segments, efv);



	fill_level = efx_channel_tx_old_fill_level(tx_queue->channel);

	if (fill_level > efx->txq_stop_thresh) {

		struct efx_tx_queue *txq2;



		/* Because of checks above, representor traffic should

		 * not be able to stop the queue.

		 */

		WARN_ON(efv);



		netif_tx_stop_queue(tx_queue->core_txq);

		/* Re-read after a memory barrier in case we've raced with

		 * the completion path. Otherwise there's a danger we'll never
@@ -404,8 +476,12 @@ int ef100_enqueue_skb(struct efx_tx_queue *tx_queue, struct sk_buff *skb) 
	/* If xmit_more then we don't need to push the doorbell, unless there

	 * are 256 descriptors already queued in which case we have to push to

	 * ensure we never push more than 256 at once.

	 *

	 * Always push for representor traffic, and don't account it to parent

	 * PF netdevice's BQL.

	 */

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

	if (unlikely(efv) ||

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

	    tx_queue->write_count - tx_queue->notify_count > 255)

		ef100_tx_push_buffers(tx_queue);

drivers/net/ethernet/sfc/ef100_tx.h

+3 −0
Original line number Diff line number Diff line
@@ -13,6 +13,7 @@ 
#define EFX_EF100_TX_H



#include "net_driver.h"

#include "ef100_rep.h"



int ef100_tx_probe(struct efx_tx_queue *tx_queue);

void ef100_tx_init(struct efx_tx_queue *tx_queue);
@@ -22,4 +23,6 @@ unsigned int ef100_tx_max_skb_descs(struct efx_nic *efx); 
void ef100_ev_tx(struct efx_channel *channel, const efx_qword_t *p_event);



netdev_tx_t ef100_enqueue_skb(struct efx_tx_queue *tx_queue, struct sk_buff *skb);

int __ef100_enqueue_skb(struct efx_tx_queue *tx_queue, struct sk_buff *skb,

			struct efx_rep *efv);

#endif

drivers/net/ethernet/sfc/net_driver.h

+1 −0
Original line number Diff line number Diff line
@@ -178,6 +178,7 @@ struct efx_tx_buffer { 
#define EFX_TX_BUF_OPTION	0x10	/* empty buffer for option descriptor */

#define EFX_TX_BUF_XDP		0x20	/* buffer was sent with XDP */

#define EFX_TX_BUF_TSO_V3	0x40	/* empty buffer for a TSO_V3 descriptor */

#define EFX_TX_BUF_EFV		0x100	/* buffer was sent from representor */



/**

 * struct efx_tx_queue - An Efx TX queue

drivers/net/ethernet/sfc/tx.c

+4 −2
Original line number Diff line number Diff line
@@ -559,6 +559,7 @@ netdev_tx_t efx_hard_start_xmit(struct sk_buff *skb, 
void efx_xmit_done_single(struct efx_tx_queue *tx_queue)

{

	unsigned int pkts_compl = 0, bytes_compl = 0;

	unsigned int efv_pkts_compl = 0;

	unsigned int read_ptr;

	bool finished = false;
@@ -580,7 +581,8 @@ void efx_xmit_done_single(struct efx_tx_queue *tx_queue) 
		/* Need to check the flag before dequeueing. */

		if (buffer->flags & EFX_TX_BUF_SKB)

			finished = true;

		efx_dequeue_buffer(tx_queue, buffer, &pkts_compl, &bytes_compl);

		efx_dequeue_buffer(tx_queue, buffer, &pkts_compl, &bytes_compl,

				   &efv_pkts_compl);



		++tx_queue->read_count;

		read_ptr = tx_queue->read_count & tx_queue->ptr_mask;
@@ -589,7 +591,7 @@ void efx_xmit_done_single(struct efx_tx_queue *tx_queue) 
	tx_queue->pkts_compl += pkts_compl;

	tx_queue->bytes_compl += bytes_compl;



	EFX_WARN_ON_PARANOID(pkts_compl != 1);

	EFX_WARN_ON_PARANOID(pkts_compl + efv_pkts_compl != 1);



	efx_xmit_done_check_empty(tx_queue);

}