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Commit 3fe13ed9 authored by Yunsheng Lin's avatar Yunsheng Lin Committed by David S. Miller
Browse files

net: hns3: avoid mult + div op in critical data path 



This patch uses shift offset to avoid doing mult and div operation.

Signed-off-by: default avatarYunsheng Lin <linyunsheng@huawei.com>
Signed-off-by: default avatarHuazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 2a73ac3e

drivers/net/ethernet/hisilicon/hns3/hns3_enet.c

+8 −7
Original line number Diff line number Diff line
@@ -658,7 +658,7 @@ static int hns3_set_tso(struct sk_buff *skb, u32 *paylen, 


	/* normal or tunnel packet*/

	l4_offset = l4.hdr - skb->data;

	hdr_len = (l4.tcp->doff * 4) + l4_offset;

	hdr_len = (l4.tcp->doff << 2) + l4_offset;



	/* remove payload length from inner pseudo checksum when tso*/

	l4_paylen = skb->len - l4_offset;
@@ -1100,8 +1100,8 @@ static int hns3_fill_desc(struct hns3_enet_ring *ring, void *priv, 


	desc_cb->length = size;



	frag_buf_num = (size + HNS3_MAX_BD_SIZE - 1) / HNS3_MAX_BD_SIZE;

	sizeoflast = size % HNS3_MAX_BD_SIZE;

	frag_buf_num = (size + HNS3_MAX_BD_SIZE - 1) >> HNS3_MAX_BD_SIZE_OFFSET;

	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 */
@@ -1145,14 +1145,14 @@ static int hns3_nic_maybe_stop_tso(struct sk_buff **out_skb, int *bnum, 
	int i;



	size = skb_headlen(skb);

	buf_num = (size + HNS3_MAX_BD_SIZE - 1) / HNS3_MAX_BD_SIZE;

	buf_num = (size + HNS3_MAX_BD_SIZE - 1) >> HNS3_MAX_BD_SIZE_OFFSET;



	frag_num = skb_shinfo(skb)->nr_frags;

	for (i = 0; i < frag_num; i++) {

		frag = &skb_shinfo(skb)->frags[i];

		size = skb_frag_size(frag);

		bdnum_for_frag =

			(size + HNS3_MAX_BD_SIZE - 1) / HNS3_MAX_BD_SIZE;

		bdnum_for_frag = (size + HNS3_MAX_BD_SIZE - 1) >>

				 HNS3_MAX_BD_SIZE_OFFSET;

		if (bdnum_for_frag > HNS3_MAX_BD_PER_FRAG)

			return -ENOMEM;
@@ -1160,7 +1160,8 @@ static int hns3_nic_maybe_stop_tso(struct sk_buff **out_skb, int *bnum, 
	}



	if (unlikely(buf_num > HNS3_MAX_BD_PER_FRAG)) {

		buf_num = (skb->len + HNS3_MAX_BD_SIZE - 1) / HNS3_MAX_BD_SIZE;

		buf_num = (skb->len + HNS3_MAX_BD_SIZE - 1) >>

			  HNS3_MAX_BD_SIZE_OFFSET;

		if (ring_space(ring) < buf_num)

			return -EBUSY;

		/* manual split the send packet */

drivers/net/ethernet/hisilicon/hns3/hns3_enet.h

+3 −0
Original line number Diff line number Diff line
@@ -184,6 +184,8 @@ enum hns3_nic_state { 
#define HNS3_TXD_MSS_S				0

#define HNS3_TXD_MSS_M				(0x3fff << HNS3_TXD_MSS_S)



#define HNS3_TX_LAST_SIZE_M                    0xffff



#define HNS3_VECTOR_TX_IRQ			BIT_ULL(0)

#define HNS3_VECTOR_RX_IRQ			BIT_ULL(1)
@@ -191,6 +193,7 @@ enum hns3_nic_state { 
#define HNS3_VECTOR_INITED			1



#define HNS3_MAX_BD_SIZE			65535

#define HNS3_MAX_BD_SIZE_OFFSET		16

#define HNS3_MAX_BD_PER_FRAG			8

#define HNS3_MAX_BD_PER_PKT			MAX_SKB_FRAGS