Commit 4bf0ca0c authored by Mike Marciniszyn's avatar Mike Marciniszyn Committed by Jason Gunthorpe
Browse files

IB/hfi1: Get rid of hot path divide 

The pointer math in this statemet does a divide;
	struct hfi1_ipoib_txq *txq = &priv->txqs[napi - priv->tx_napis];

Elminate the divide by embedding the struct napi_strut in the txq and
getting the txq with a container_of() using the newly embedded napi.

Fixes: d99dc602 ("IB/hfi1: Add functions to transmit datagram ipoib packets")
Link: https://lore.kernel.org/r/20210913132831.131370.3993.stgit@awfm-01.cornelisnetworks.com


Reviewed-by: default avatarDennis Dalessandro <dennis.dalessandro@cornelisnetworks.com>
Signed-off-by: default avatarMike Marciniszyn <mike.marciniszyn@cornelisnetworks.com>
Signed-off-by: default avatarDennis Dalessandro <dennis.dalessandro@cornelisnetworks.com>
Signed-off-by: default avatarJason Gunthorpe <jgg@nvidia.com>
parent d47dfc2b

drivers/infiniband/hw/hfi1/ipoib.h

+1 −2
Original line number Diff line number Diff line
@@ -78,6 +78,7 @@ struct hfi1_ipoib_circ_buf { 
 * @tx_ring: ring of ipoib txreqs to be reaped by napi callback

 */

struct hfi1_ipoib_txq {

	struct napi_struct napi;

	struct hfi1_ipoib_dev_priv *priv;

	struct sdma_engine *sde;

	struct list_head tx_list;
@@ -91,7 +92,6 @@ struct hfi1_ipoib_txq { 
	struct iowait wait;



	atomic64_t ____cacheline_aligned_in_smp complete_txreqs;

	struct napi_struct *napi;

	struct hfi1_ipoib_circ_buf tx_ring;

};
@@ -100,7 +100,6 @@ struct hfi1_ipoib_dev_priv { 
	struct net_device   *netdev;

	struct ib_device    *device;

	struct hfi1_ipoib_txq *txqs;

	struct napi_struct *tx_napis;

	u16 pkey;

	u16 pkey_index;

	u32 qkey;

drivers/infiniband/hw/hfi1/ipoib_tx.c

+10 −25
Original line number Diff line number Diff line
@@ -172,8 +172,8 @@ static void hfi1_ipoib_drain_tx_ring(struct hfi1_ipoib_txq *txq) 


static int hfi1_ipoib_poll_tx_ring(struct napi_struct *napi, int budget)

{

	struct hfi1_ipoib_dev_priv *priv = hfi1_ipoib_priv(napi->dev);

	struct hfi1_ipoib_txq *txq = &priv->txqs[napi - priv->tx_napis];

	struct hfi1_ipoib_txq *txq =

		container_of(napi, struct hfi1_ipoib_txq, napi);

	struct hfi1_ipoib_circ_buf *tx_ring = &txq->tx_ring;

	u32 head = tx_ring->head;

	u32 max_tx = tx_ring->max_items;
@@ -211,7 +211,7 @@ static void hfi1_ipoib_sdma_complete(struct sdma_txreq *txreq, int status) 
	tx->sdma_status = status;

	/* see hfi1_ipoib_poll_tx_ring */

	smp_store_release(&tx->complete, 1);

	napi_schedule_irqoff(tx->txq->napi);

	napi_schedule_irqoff(&tx->txq->napi);

}



static int hfi1_ipoib_build_ulp_payload(struct ipoib_txreq *tx,
@@ -505,7 +505,7 @@ static int hfi1_ipoib_send_dma_single(struct net_device *dev, 


	/* mark complete and kick napi tx */

	smp_store_release(&tx->complete, 1);

	napi_schedule(tx->txq->napi);

	napi_schedule(&tx->txq->napi);



	++dev->stats.tx_carrier_errors;
@@ -693,13 +693,6 @@ int hfi1_ipoib_txreq_init(struct hfi1_ipoib_dev_priv *priv) 
	u32 tx_ring_size, tx_item_size;

	int i;



	priv->tx_napis = kcalloc_node(dev->num_tx_queues,

				      sizeof(struct napi_struct),

				      GFP_KERNEL,

				      priv->dd->node);

	if (!priv->tx_napis)

		return -ENOMEM;



	/*

	 * Ring holds 1 less than tx_ring_size

	 * Round up to next power of 2 in order to hold at least tx_queue_len
@@ -712,7 +705,7 @@ int hfi1_ipoib_txreq_init(struct hfi1_ipoib_dev_priv *priv) 
				  GFP_KERNEL,

				  priv->dd->node);

	if (!priv->txqs)

		goto free_tx_napis;

		return -ENOMEM;



	for (i = 0; i < dev->num_tx_queues; i++) {

		struct hfi1_ipoib_txq *txq = &priv->txqs[i];
@@ -749,8 +742,7 @@ int hfi1_ipoib_txreq_init(struct hfi1_ipoib_dev_priv *priv) 
		txq->tx_ring.max_items = tx_ring_size;

		txq->tx_ring.shift = ilog2(tx_ring_size);



		txq->napi = &priv->tx_napis[i];

		netif_tx_napi_add(dev, txq->napi,

		netif_tx_napi_add(dev, &txq->napi,

				  hfi1_ipoib_poll_tx_ring,

				  NAPI_POLL_WEIGHT);

	}
@@ -761,16 +753,12 @@ int hfi1_ipoib_txreq_init(struct hfi1_ipoib_dev_priv *priv) 
	for (i--; i >= 0; i--) {

		struct hfi1_ipoib_txq *txq = &priv->txqs[i];



		netif_napi_del(txq->napi);

		netif_napi_del(&txq->napi);

		kfree(txq->tx_ring.items);

	}



	kfree(priv->txqs);

	priv->txqs = NULL;



free_tx_napis:

	kfree(priv->tx_napis);

	priv->tx_napis = NULL;

	return -ENOMEM;

}
@@ -809,16 +797,13 @@ void hfi1_ipoib_txreq_deinit(struct hfi1_ipoib_dev_priv *priv) 
		iowait_cancel_work(&txq->wait);

		iowait_sdma_drain(&txq->wait);

		hfi1_ipoib_drain_tx_list(txq);

		netif_napi_del(txq->napi);

		netif_napi_del(&txq->napi);

		hfi1_ipoib_drain_tx_ring(txq);

		kfree(txq->tx_ring.items);

	}



	kfree(priv->txqs);

	priv->txqs = NULL;



	kfree(priv->tx_napis);

	priv->tx_napis = NULL;

}



void hfi1_ipoib_napi_tx_enable(struct net_device *dev)
@@ -829,7 +814,7 @@ void hfi1_ipoib_napi_tx_enable(struct net_device *dev) 
	for (i = 0; i < dev->num_tx_queues; i++) {

		struct hfi1_ipoib_txq *txq = &priv->txqs[i];



		napi_enable(txq->napi);

		napi_enable(&txq->napi);

	}

}
@@ -841,7 +826,7 @@ void hfi1_ipoib_napi_tx_disable(struct net_device *dev) 
	for (i = 0; i < dev->num_tx_queues; i++) {

		struct hfi1_ipoib_txq *txq = &priv->txqs[i];



		napi_disable(txq->napi);

		napi_disable(&txq->napi);

		hfi1_ipoib_drain_tx_ring(txq);

	}

}