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Message-ID: <d68206d9-d72d-6669-c083-944b23b11616@mellanox.com>
Date: Tue, 27 Mar 2018 00:23:54 +0300
From: Tal Gilboa <talgi@...lanox.com>
To: Florian Fainelli <f.fainelli@...il.com>, netdev@...r.kernel.org
Cc: davem@...emloft.net, jaedon.shin@...il.com, pgynther@...gle.com,
opendmb@...il.com, michal.chan@...adcom.com, gospo@...adcom.com,
saeedm@...lanox.com
Subject: Re: [PATCH net-next 2/2] net: bcmgenet: Add support for adaptive RX
coalescing
On 3/23/2018 4:19 AM, Florian Fainelli wrote:
> 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: Florian Fainelli <f.fainelli@...il.com>
> ---
> drivers/net/ethernet/broadcom/genet/bcmgenet.c | 109 +++++++++++++++++++++----
> drivers/net/ethernet/broadcom/genet/bcmgenet.h | 12 +++
> 2 files changed, 103 insertions(+), 18 deletions(-)
>
> diff --git a/drivers/net/ethernet/broadcom/genet/bcmgenet.c b/drivers/net/ethernet/broadcom/genet/bcmgenet.c
> index b1e35a9accf1..7db8edc643ec 100644
> --- a/drivers/net/ethernet/broadcom/genet/bcmgenet.c
> +++ b/drivers/net/ethernet/broadcom/genet/bcmgenet.c
> @@ -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);
> +}
> +
Similar comments from path 1/2 apply here - wouldn't couple the genric
get_set_coalesce functions with dim.
> 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;
> +} > +
Similar comment from path 1/2 applies here - default values for
coal_usecs/pkts.
> /* 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);
> diff --git a/drivers/net/ethernet/broadcom/genet/bcmgenet.h b/drivers/net/ethernet/broadcom/genet/bcmgenet.h
> index 3c50431ccd2a..22c41e0430fb 100644
> --- a/drivers/net/ethernet/broadcom/genet/bcmgenet.h
> +++ b/drivers/net/ethernet/broadcom/genet/bcmgenet.h
> @@ -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;
>
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