[net-next,2/3] octeon_ep: implement xmit_more in transmit
Commit Message
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(-)
Comments
> -----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
@@ -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
@@ -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: