[PATCH net-next 06/12] net: hns3: minor optimization for datapath

From: Huazhong Tan
Date: Tue Apr 02 2019 - 23:09:53 EST


From: Yunsheng Lin <linyunsheng@xxxxxxxxxx>

This patch adds a likely case for hns3_fill_desc and
limits the local variables' scope as much as possible,
also avoid div operation when the tqp_vector->num_tqps
is one.

Signed-off-by: Yunsheng Lin <linyunsheng@xxxxxxxxxx>
Signed-off-by: Peng Li <lipeng321@xxxxxxxxxx>
Signed-off-by: Huazhong Tan <tanhuazhong@xxxxxxxxxx>
---
drivers/net/ethernet/hisilicon/hns3/hns3_enet.c | 24 +++++++++++++++++++++---
1 file changed, 21 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c
index 21085c4..5b34d2e 100644
--- a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c
+++ b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c
@@ -1012,7 +1012,6 @@ static int hns3_fill_desc(struct hns3_enet_ring *ring, void *priv,
struct hns3_desc_cb *desc_cb = &ring->desc_cb[ring->next_to_use];
struct hns3_desc *desc = &ring->desc[ring->next_to_use];
struct device *dev = ring_to_dev(ring);
- u16 bdtp_fe_sc_vld_ra_ri = 0;
struct skb_frag_struct *frag;
unsigned int frag_buf_num;
int k, sizeoflast;
@@ -1080,12 +1079,30 @@ static int hns3_fill_desc(struct hns3_enet_ring *ring, void *priv,

desc_cb->length = size;

+ if (likely(size <= HNS3_MAX_BD_SIZE)) {
+ u16 bdtp_fe_sc_vld_ra_ri = 0;
+
+ desc_cb->priv = priv;
+ desc_cb->dma = dma;
+ desc_cb->type = type;
+ desc->addr = cpu_to_le64(dma);
+ desc->tx.send_size = cpu_to_le16(size);
+ hns3_set_txbd_baseinfo(&bdtp_fe_sc_vld_ra_ri, frag_end);
+ desc->tx.bdtp_fe_sc_vld_ra_ri =
+ cpu_to_le16(bdtp_fe_sc_vld_ra_ri);
+
+ ring_ptr_move_fw(ring, next_to_use);
+ return 0;
+ }
+
frag_buf_num = hns3_tx_bd_count(size);
sizeoflast = size & HNS3_TX_LAST_SIZE_M;
sizeoflast = sizeoflast ? sizeoflast : HNS3_MAX_BD_SIZE;

/* When frag size is bigger than hardware limit, split this frag */
for (k = 0; k < frag_buf_num; k++) {
+ u16 bdtp_fe_sc_vld_ra_ri = 0;
+
/* The txbd's baseinfo of DESC_TYPE_PAGE & DESC_TYPE_SKB */
desc_cb->priv = priv;
desc_cb->dma = dma + HNS3_MAX_BD_SIZE * k;
@@ -2891,7 +2908,7 @@ static int hns3_nic_common_poll(struct napi_struct *napi, int budget)
struct hns3_enet_tqp_vector *tqp_vector =
container_of(napi, struct hns3_enet_tqp_vector, napi);
bool clean_complete = true;
- int rx_budget;
+ int rx_budget = budget;

if (unlikely(test_bit(HNS3_NIC_STATE_DOWN, &priv->state))) {
napi_complete(napi);
@@ -2905,7 +2922,8 @@ static int hns3_nic_common_poll(struct napi_struct *napi, int budget)
hns3_clean_tx_ring(ring);

/* make sure rx ring budget not smaller than 1 */
- rx_budget = max(budget / tqp_vector->num_tqps, 1);
+ if (tqp_vector->num_tqps > 1)
+ rx_budget = max(budget / tqp_vector->num_tqps, 1);

hns3_for_each_ring(ring, tqp_vector->rx_group) {
int rx_cleaned = hns3_clean_rx_ring(ring, rx_budget,
--
2.7.4