From: Stephen Hemminger <stephen@networkplumber.org>
Date: Fri, 1 Dec 2017 11:01:46 -0800
Patch-mainline: v4.16-rc1
Subject: hv_netvsc: replace divide with mask when computing padding
Git-commit: b85e06f7bb1a25dd2e7755d55a2ca313d24ae7ad
References: fate#323887

Packet alignment is always a power of 2 therefore modulus can
be replaced with a faster and operation

Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Olaf Hering <ohering@suse.de>
---
 drivers/net/hyperv/netvsc.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/net/hyperv/netvsc.c b/drivers/net/hyperv/netvsc.c
--- a/drivers/net/hyperv/netvsc.c
+++ b/drivers/net/hyperv/netvsc.c
@@ -712,11 +712,12 @@ static u32 netvsc_copy_to_send_buf(struct netvsc_device *net_device,
 	int i;
 	u32 msg_size = 0;
 	u32 padding = 0;
-	u32 remain = packet->total_data_buflen % net_device->pkt_align;
 	u32 page_count = packet->cp_partial ? packet->rmsg_pgcnt :
 		packet->page_buf_cnt;
+	u32 remain;
 
 	/* Add padding */
+	remain = packet->total_data_buflen & (net_device->pkt_align - 1);
 	if (skb->xmit_more && remain && !packet->cp_partial) {
 		padding = net_device->pkt_align - remain;
 		rndis_msg->msg_len += padding;