[PATCH net-next v2 3/4] octeon_ep: implement xmit_more in transmit

From: Shinas Rasheed
Date: Tue Oct 24 2023 - 10:52:00 EST


Add xmit_more handling in tx datapath for octeon_ep pf.

Signed-off-by: Shinas Rasheed <srasheed@xxxxxxxxxxx>
---
V2:
- Updated changelog to have imperative tone.
V1: https://lore.kernel.org/all/20231023114449.2362147-3-srasheed@xxxxxxxxxxx/

.../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 1c02304677c9..1a88a6bf0598 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;

if (skb_put_padto(skb, ETH_ZLEN))
@@ -895,18 +896,28 @@ 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