Adds xmit_more handling in tx datapath for octeon_ep pf.

Signed-off-by: Shinas Rasheed <srasheed@marvell.com>
---
 .../ethernet/marvell/octeon_ep/octep_config.h |  2 +-
 .../ethernet/marvell/octeon_ep/octep_main.c   | 19 +++++++++++++++----
 2 files changed, 16 insertions(+), 5 deletions(-)

diff --git a/drivers/net/ethernet/marvell/octeon_ep/octep_config.h b/drivers/net/ethernet/marvell/octeon_ep/octep_config.h
index 1622a6ebf036..ed8b1ace56b9 100644
--- a/drivers/net/ethernet/marvell/octeon_ep/octep_config.h
+++ b/drivers/net/ethernet/marvell/octeon_ep/octep_config.h
@@ -15,7 +15,7 @@
 /* Tx Queue: maximum descriptors per ring */
 #define OCTEP_IQ_MAX_DESCRIPTORS    1024
 /* Minimum input (Tx) requests to be enqueued to ring doorbell */
-#define OCTEP_DB_MIN                1
+#define OCTEP_DB_MIN                8
 /* Packet threshold for Tx queue interrupt */
 #define OCTEP_IQ_INTR_THRESHOLD     0x0
 
diff --git a/drivers/net/ethernet/marvell/octeon_ep/octep_main.c b/drivers/net/ethernet/marvell/octeon_ep/octep_main.c
index bf1e376a4232..730443ba2f5b 100644
--- a/drivers/net/ethernet/marvell/octeon_ep/octep_main.c
+++ b/drivers/net/ethernet/marvell/octeon_ep/octep_main.c
@@ -818,6 +818,7 @@ static netdev_tx_t octep_start_xmit(struct sk_buff *skb,
 	struct octep_iq *iq;
 	skb_frag_t *frag;
 	u16 nr_frags, si;
+	int xmit_more;
 	u16 q_no, wi;
 
 	q_no = skb_get_queue_mapping(skb);
@@ -892,18 +893,28 @@ static netdev_tx_t octep_start_xmit(struct sk_buff *skb,
 	}
 
 	netdev_tx_sent_queue(iq->netdev_q, skb->len);
+
+	xmit_more = netdev_xmit_more();
+
 	skb_tx_timestamp(skb);
 	atomic_inc(&iq->instr_pending);
+	iq->fill_cnt++;
 	wi++;
 	if (wi == iq->max_count)
 		wi = 0;
 	iq->host_write_index = wi;
+	if (xmit_more &&
+	    (atomic_read(&iq->instr_pending) <
+	     (iq->max_count - OCTEP_WAKE_QUEUE_THRESHOLD)) &&
+	    iq->fill_cnt < iq->fill_threshold)
+		return NETDEV_TX_OK;
+
 	/* Flush the hw descriptor before writing to doorbell */
 	wmb();
-
-	/* Ring Doorbell to notify the NIC there is a new packet */
-	writel(1, iq->doorbell_reg);
-	iq->stats.instr_posted++;
+	/* Ring Doorbell to notify the NIC of new packets */
+	writel(iq->fill_cnt, iq->doorbell_reg);
+	iq->stats.instr_posted += iq->fill_cnt;
+	iq->fill_cnt = 0;
 	return NETDEV_TX_OK;
 
 dma_map_sg_err:
-- 
2.25.1

> -----Original Message-----
> From: Shinas Rasheed <srasheed@marvell.com>
> Sent: Monday, October 23, 2023 1:45 PM
> To: netdev@vger.kernel.org; linux-kernel@vger.kernel.org
> Cc: hgani@marvell.com; vimleshk@marvell.com; Gallen, Erwan <egallen@redhat.com>; mschmidt <mschmidt@redhat.com>;
> pabeni@redhat.com; horms@kernel.org; kuba@kernel.org; davem@davemloft.net; Shinas Rasheed <srasheed@marvell.com>;
> Veerasenareddy Burru <vburru@marvell.com>; Sathesh Edara <sedara@marvell.com>; Eric Dumazet <edumazet@google.com>
> Subject: [PATCH net-next 2/3] octeon_ep: implement xmit_more in transmit
> 
> Adds xmit_more handling in tx datapath for octeon_ep pf.

Imperative mode is preferred :)
Besides that:
Reviewed-by: Wojciech Drewek <wojciech.drewek@intel.com>

> 
> Signed-off-by: Shinas Rasheed <srasheed@marvell.com>
> ---
>  .../ethernet/marvell/octeon_ep/octep_config.h |  2 +-
>  .../ethernet/marvell/octeon_ep/octep_main.c   | 19 +++++++++++++++----
>  2 files changed, 16 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/net/ethernet/marvell/octeon_ep/octep_config.h b/drivers/net/ethernet/marvell/octeon_ep/octep_config.h
> index 1622a6ebf036..ed8b1ace56b9 100644
> --- a/drivers/net/ethernet/marvell/octeon_ep/octep_config.h
> +++ b/drivers/net/ethernet/marvell/octeon_ep/octep_config.h
> @@ -15,7 +15,7 @@
>  /* Tx Queue: maximum descriptors per ring */
>  #define OCTEP_IQ_MAX_DESCRIPTORS    1024
>  /* Minimum input (Tx) requests to be enqueued to ring doorbell */
> -#define OCTEP_DB_MIN                1
> +#define OCTEP_DB_MIN                8
>  /* Packet threshold for Tx queue interrupt */
>  #define OCTEP_IQ_INTR_THRESHOLD     0x0
> 
> diff --git a/drivers/net/ethernet/marvell/octeon_ep/octep_main.c b/drivers/net/ethernet/marvell/octeon_ep/octep_main.c
> index bf1e376a4232..730443ba2f5b 100644
> --- a/drivers/net/ethernet/marvell/octeon_ep/octep_main.c
> +++ b/drivers/net/ethernet/marvell/octeon_ep/octep_main.c
> @@ -818,6 +818,7 @@ static netdev_tx_t octep_start_xmit(struct sk_buff *skb,
>  	struct octep_iq *iq;
>  	skb_frag_t *frag;
>  	u16 nr_frags, si;
> +	int xmit_more;
>  	u16 q_no, wi;
> 
>  	q_no = skb_get_queue_mapping(skb);
> @@ -892,18 +893,28 @@ static netdev_tx_t octep_start_xmit(struct sk_buff *skb,
>  	}
> 
>  	netdev_tx_sent_queue(iq->netdev_q, skb->len);
> +
> +	xmit_more = netdev_xmit_more();
> +
>  	skb_tx_timestamp(skb);
>  	atomic_inc(&iq->instr_pending);
> +	iq->fill_cnt++;
>  	wi++;
>  	if (wi == iq->max_count)
>  		wi = 0;
>  	iq->host_write_index = wi;
> +	if (xmit_more &&
> +	    (atomic_read(&iq->instr_pending) <
> +	     (iq->max_count - OCTEP_WAKE_QUEUE_THRESHOLD)) &&
> +	    iq->fill_cnt < iq->fill_threshold)
> +		return NETDEV_TX_OK;
> +
>  	/* Flush the hw descriptor before writing to doorbell */
>  	wmb();
> -
> -	/* Ring Doorbell to notify the NIC there is a new packet */
> -	writel(1, iq->doorbell_reg);
> -	iq->stats.instr_posted++;
> +	/* Ring Doorbell to notify the NIC of new packets */
> +	writel(iq->fill_cnt, iq->doorbell_reg);
> +	iq->stats.instr_posted += iq->fill_cnt;
> +	iq->fill_cnt = 0;
>  	return NETDEV_TX_OK;
> 
>  dma_map_sg_err:
> --
> 2.25.1
> 

Sure, will update it since the first patch changelog requires more explanation as well