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Commit 9f4ca058 authored by Florian Fainelli's avatar Florian Fainelli Committed by David S. Miller
Browse files

net: bcmgenet: Add support for adaptive RX coalescing 



Unlike the moder modern SYSTEMPORT hardware, we do not have a
configurable TDMA timeout, which limits us to implement adaptive RX
interrupt coalescing only. We have each of our RX rings implement a
bcmgenet_net_dim structure which holds an interrupt counter, number of
packets, bytes, and a container for a net_dim instance.

Signed-off-by: default avatarFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent b6e0e875

drivers/net/ethernet/broadcom/genet/bcmgenet.c

+91 −18
Original line number Diff line number Diff line
@@ -603,6 +603,8 @@ static int bcmgenet_get_coalesce(struct net_device *dev, 
				 struct ethtool_coalesce *ec)

{

	struct bcmgenet_priv *priv = netdev_priv(dev);

	struct bcmgenet_rx_ring *ring;

	unsigned int i;



	ec->tx_max_coalesced_frames =

		bcmgenet_tdma_ring_readl(priv, DESC_INDEX,
@@ -613,15 +615,37 @@ static int bcmgenet_get_coalesce(struct net_device *dev, 
	ec->rx_coalesce_usecs =

		bcmgenet_rdma_readl(priv, DMA_RING16_TIMEOUT) * 8192 / 1000;



	for (i = 0; i < priv->hw_params->rx_queues; i++) {

		ring = &priv->rx_rings[i];

		ec->use_adaptive_rx_coalesce |= ring->dim.use_dim;

	}

	ring = &priv->rx_rings[DESC_INDEX];

	ec->use_adaptive_rx_coalesce |= ring->dim.use_dim;



	return 0;

}



static void bcmgenet_set_rx_coalesce(struct bcmgenet_rx_ring *ring)

{

	struct bcmgenet_priv *priv = ring->priv;

	unsigned int i = ring->index;

	u32 reg;



	bcmgenet_rdma_ring_writel(priv, i, ring->dim.coal_pkts,

				  DMA_MBUF_DONE_THRESH);



	reg = bcmgenet_rdma_readl(priv, DMA_RING0_TIMEOUT + i);

	reg &= ~DMA_TIMEOUT_MASK;

	reg |= DIV_ROUND_UP(ring->dim.coal_usecs * 1000, 8192);

	bcmgenet_rdma_writel(priv, reg, DMA_RING0_TIMEOUT + i);

}



static int bcmgenet_set_coalesce(struct net_device *dev,

				 struct ethtool_coalesce *ec)

{

	struct bcmgenet_priv *priv = netdev_priv(dev);

	struct bcmgenet_rx_ring *ring;

	unsigned int i;

	u32 reg;



	/* Base system clock is 125Mhz, DMA timeout is this reference clock

	 * divided by 1024, which yields roughly 8.192us, our maximum value
@@ -641,7 +665,8 @@ static int bcmgenet_set_coalesce(struct net_device *dev, 
	 * transmitted, or when the ring is empty.

	 */

	if (ec->tx_coalesce_usecs || ec->tx_coalesce_usecs_high ||

	    ec->tx_coalesce_usecs_irq || ec->tx_coalesce_usecs_low)

	    ec->tx_coalesce_usecs_irq || ec->tx_coalesce_usecs_low ||

	    ec->use_adaptive_tx_coalesce)

		return -EOPNOTSUPP;



	/* Program all TX queues with the same values, as there is no
@@ -656,24 +681,26 @@ static int bcmgenet_set_coalesce(struct net_device *dev, 
				  DMA_MBUF_DONE_THRESH);



	for (i = 0; i < priv->hw_params->rx_queues; i++) {

		bcmgenet_rdma_ring_writel(priv, i,

					  ec->rx_max_coalesced_frames,

					  DMA_MBUF_DONE_THRESH);



		reg = bcmgenet_rdma_readl(priv, DMA_RING0_TIMEOUT + i);

		reg &= ~DMA_TIMEOUT_MASK;

		reg |= DIV_ROUND_UP(ec->rx_coalesce_usecs * 1000, 8192);

		bcmgenet_rdma_writel(priv, reg, DMA_RING0_TIMEOUT + i);

		ring = &priv->rx_rings[i];

		ring->dim.coal_usecs = ec->rx_coalesce_usecs;

		ring->dim.coal_pkts = ec->rx_max_coalesced_frames;

		if (!ec->use_adaptive_rx_coalesce && ring->dim.use_dim) {

			ring->dim.coal_pkts = 1;

			ring->dim.coal_usecs = 0;

		}

		ring->dim.use_dim = ec->use_adaptive_rx_coalesce;

		bcmgenet_set_rx_coalesce(ring);

	}



	bcmgenet_rdma_ring_writel(priv, DESC_INDEX,

				  ec->rx_max_coalesced_frames,

				  DMA_MBUF_DONE_THRESH);



	reg = bcmgenet_rdma_readl(priv, DMA_RING16_TIMEOUT);

	reg &= ~DMA_TIMEOUT_MASK;

	reg |= DIV_ROUND_UP(ec->rx_coalesce_usecs * 1000, 8192);

	bcmgenet_rdma_writel(priv, reg, DMA_RING16_TIMEOUT);

	ring = &priv->rx_rings[DESC_INDEX];

	ring->dim.coal_usecs = ec->rx_coalesce_usecs;

	ring->dim.coal_pkts = ec->rx_max_coalesced_frames;

	if (!ec->use_adaptive_rx_coalesce && ring->dim.use_dim) {

		ring->dim.coal_pkts = 1;

		ring->dim.coal_usecs = 0;

	}

	ring->dim.use_dim = ec->use_adaptive_rx_coalesce;

	bcmgenet_set_rx_coalesce(ring);



	return 0;

}
@@ -1713,6 +1740,7 @@ static unsigned int bcmgenet_desc_rx(struct bcmgenet_rx_ring *ring, 
	unsigned long dma_flag;

	int len;

	unsigned int rxpktprocessed = 0, rxpkttoprocess;

	unsigned int bytes_processed = 0;

	unsigned int p_index, mask;

	unsigned int discards;

	unsigned int chksum_ok = 0;
@@ -1832,6 +1860,8 @@ static unsigned int bcmgenet_desc_rx(struct bcmgenet_rx_ring *ring, 
			len -= ETH_FCS_LEN;

		}



		bytes_processed += len;



		/*Finish setting up the received SKB and send it to the kernel*/

		skb->protocol = eth_type_trans(skb, priv->dev);

		ring->packets++;
@@ -1854,6 +1884,9 @@ static unsigned int bcmgenet_desc_rx(struct bcmgenet_rx_ring *ring, 
		bcmgenet_rdma_ring_writel(priv, ring->index, ring->c_index, RDMA_CONS_INDEX);

	}



	ring->dim.bytes = bytes_processed;

	ring->dim.packets = rxpktprocessed;



	return rxpktprocessed;

}
@@ -1862,6 +1895,7 @@ static int bcmgenet_rx_poll(struct napi_struct *napi, int budget) 
{

	struct bcmgenet_rx_ring *ring = container_of(napi,

			struct bcmgenet_rx_ring, napi);

	struct net_dim_sample dim_sample;

	unsigned int work_done;



	work_done = bcmgenet_desc_rx(ring, budget);
@@ -1871,9 +1905,32 @@ static int bcmgenet_rx_poll(struct napi_struct *napi, int budget) 
		ring->int_enable(ring);

	}



	if (ring->dim.use_dim) {

		net_dim_sample(ring->dim.event_ctr, ring->dim.packets,

			       ring->dim.bytes, &dim_sample);

		net_dim(&ring->dim.dim, dim_sample);

	}



	return work_done;

}



static void bcmgenet_dim_work(struct work_struct *work)

{

	struct net_dim *dim = container_of(work, struct net_dim, work);

	struct bcmgenet_net_dim *ndim =

			container_of(dim, struct bcmgenet_net_dim, dim);

	struct bcmgenet_rx_ring *ring =

			container_of(ndim, struct bcmgenet_rx_ring, dim);

	struct net_dim_cq_moder cur_profile =

			net_dim_get_profile(dim->mode, dim->profile_ix);



	ring->dim.coal_usecs = cur_profile.usec;

	ring->dim.coal_pkts = cur_profile.pkts;



	bcmgenet_set_rx_coalesce(ring);

	dim->state = NET_DIM_START_MEASURE;

}



/* Assign skb to RX DMA descriptor. */

static int bcmgenet_alloc_rx_buffers(struct bcmgenet_priv *priv,

				     struct bcmgenet_rx_ring *ring)
@@ -2022,6 +2079,16 @@ static void init_umac(struct bcmgenet_priv *priv) 
	dev_dbg(kdev, "done init umac\n");

}



static void bcmgenet_init_dim(struct bcmgenet_net_dim *dim,

			      void (*cb)(struct work_struct *work))

{

	INIT_WORK(&dim->dim.work, cb);

	dim->dim.mode = NET_DIM_CQ_PERIOD_MODE_START_FROM_EQE;

	dim->event_ctr = 0;

	dim->packets = 0;

	dim->bytes = 0;

}



/* Initialize a Tx ring along with corresponding hardware registers */

static void bcmgenet_init_tx_ring(struct bcmgenet_priv *priv,

				  unsigned int index, unsigned int size,
@@ -2111,6 +2178,8 @@ static int bcmgenet_init_rx_ring(struct bcmgenet_priv *priv, 
	if (ret)

		return ret;



	bcmgenet_init_dim(&ring->dim, bcmgenet_dim_work);



	/* Initialize Rx NAPI */

	netif_napi_add(priv->dev, &ring->napi, bcmgenet_rx_poll,

		       NAPI_POLL_WEIGHT);
@@ -2276,10 +2345,12 @@ static void bcmgenet_disable_rx_napi(struct bcmgenet_priv *priv) 
	for (i = 0; i < priv->hw_params->rx_queues; ++i) {

		ring = &priv->rx_rings[i];

		napi_disable(&ring->napi);

		cancel_work_sync(&ring->dim.dim.work);

	}



	ring = &priv->rx_rings[DESC_INDEX];

	napi_disable(&ring->napi);

	cancel_work_sync(&ring->dim.dim.work);

}



static void bcmgenet_fini_rx_napi(struct bcmgenet_priv *priv)
@@ -2557,6 +2628,7 @@ static irqreturn_t bcmgenet_isr1(int irq, void *dev_id) 
			continue;



		rx_ring = &priv->rx_rings[index];

		rx_ring->dim.event_ctr++;



		if (likely(napi_schedule_prep(&rx_ring->napi))) {

			rx_ring->int_disable(rx_ring);
@@ -2601,6 +2673,7 @@ static irqreturn_t bcmgenet_isr0(int irq, void *dev_id) 


	if (status & UMAC_IRQ_RXDMA_DONE) {

		rx_ring = &priv->rx_rings[DESC_INDEX];

		rx_ring->dim.event_ctr++;



		if (likely(napi_schedule_prep(&rx_ring->napi))) {

			rx_ring->int_disable(rx_ring);

drivers/net/ethernet/broadcom/genet/bcmgenet.h

+12 −0
Original line number Diff line number Diff line
@@ -16,6 +16,7 @@ 
#include <linux/mii.h>

#include <linux/if_vlan.h>

#include <linux/phy.h>

#include <linux/net_dim.h>



/* total number of Buffer Descriptors, same for Rx/Tx */

#define TOTAL_DESC				256
@@ -572,6 +573,16 @@ struct bcmgenet_tx_ring { 
	struct bcmgenet_priv *priv;

};



struct bcmgenet_net_dim {

	u16		use_dim;

	u16		event_ctr;

	unsigned long	packets;

	unsigned long	bytes;

	u32		coal_usecs;

	u32		coal_pkts;

	struct net_dim	dim;

};



struct bcmgenet_rx_ring {

	struct napi_struct napi;	/* Rx NAPI struct */

	unsigned long	bytes;
@@ -586,6 +597,7 @@ struct bcmgenet_rx_ring { 
	unsigned int	cb_ptr;		/* Rx ring initial CB ptr */

	unsigned int	end_ptr;	/* Rx ring end CB ptr */

	unsigned int	old_discards;

	struct bcmgenet_net_dim dim;

	void (*int_enable)(struct bcmgenet_rx_ring *);

	void (*int_disable)(struct bcmgenet_rx_ring *);

	struct bcmgenet_priv *priv;