From 4d887b7901d59b472df97bd8a2f8bdeb43be7ced Mon Sep 17 00:00:00 2001
From: Yunsheng Lin <linyunsheng@huawei.com>
Date: Tue, 18 Dec 2018 19:37:59 +0800
Subject: [PATCH 22/31] net: hns3: fix a SSU buffer checking bug
Origin: https://git.kernel.org/linus/af854724e51e4047f534ac6d19b3ef9fb3c35c49

When caculating the SSU buffer, it first allocate tx and
rx private buffer, then the remaining buffer is for rx
shared buffer. The remaining buffer size should be at
least bigger than or equal to the shared_std, which is the
minimum shared buffer size required by the driver, but
currently if the remaining buffer size is equal to the
shared_std, it returns failure, which causes SSU buffer
allocation failure problem.

This patch fixes this problem by rounding up shared_std before
checking the the remaining buffer size bigger than or equal to
the shared_std.

Fixes: 46a3df9f9718 ("net: hns3: Add HNS3 Acceleration Engine & Compatibility Layer Support")
Signed-off-by: Yunsheng Lin <linyunsheng@huawei.com>
Signed-off-by: Peng Li <lipeng321@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
 drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_main.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

Index: linux/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_main.c
===================================================================
--- linux.orig/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_main.c
+++ linux/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_main.c
@@ -1620,10 +1620,11 @@ static bool  hclge_is_rx_buf_ok(struct h
 	shared_buf_tc = pfc_enable_num * aligned_mps +
 			(tc_num - pfc_enable_num) * aligned_mps / 2 +
 			aligned_mps;
-	shared_std = max_t(u32, shared_buf_min, shared_buf_tc);
+	shared_std = roundup(max_t(u32, shared_buf_min, shared_buf_tc),
+			     HCLGE_BUF_SIZE_UNIT);
 
 	rx_priv = hclge_get_rx_priv_buff_alloced(buf_alloc);
-	if (rx_all <= rx_priv + shared_std)
+	if (rx_all < rx_priv + shared_std)
 		return false;
 
 	shared_buf = rounddown(rx_all - rx_priv, HCLGE_BUF_SIZE_UNIT);
