From: Yunsheng Lin <linyunsheng@huawei.com>
Date: Sun, 14 Apr 2019 09:47:41 +0800
Subject: net: hns3: always assume no drop TC for performance reason
Patch-mainline: v5.2-rc1
Git-commit: db5936db8f9e024cdbb988dab1606f2c205bb385
References: bsc#1104353 FATE#326415 bsc#1135049

Currently RX shared buffer' threshold size for speific TC is
set to smaller value when the TC's PFC is not enabled, which may
cause performance problem because hardware may not have enough
hardware buffer when PFC is not enabled.

This patch sets the same threshold size for all TC no matter if
the specific TC's PFC is enabled.

Signed-off-by: Yunsheng Lin <linyunsheng@huawei.com>
Signed-off-by: Peng Li <lipeng321@huawei.com>
Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_main.c |   29 ++--------------
 1 file changed, 4 insertions(+), 25 deletions(-)

--- a/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_main.c
+++ b/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_main.c
@@ -1432,17 +1432,6 @@ static int hclge_get_tc_num(struct hclge
 	return cnt;
 }
 
-static int hclge_get_pfc_enalbe_num(struct hclge_dev *hdev)
-{
-	int i, cnt = 0;
-
-	for (i = 0; i < HCLGE_MAX_TC_NUM; i++)
-		if (hdev->hw_tc_map & BIT(i) &&
-		    hdev->tm_info.hw_pfc_map & BIT(i))
-			cnt++;
-	return cnt;
-}
-
 /* Get the number of pfc enabled TCs, which have private buffer */
 static int hclge_get_pfc_priv_num(struct hclge_dev *hdev,
 				  struct hclge_pkt_buf_alloc *buf_alloc)
@@ -1507,13 +1496,11 @@ static bool  hclge_is_rx_buf_ok(struct h
 				u32 rx_all)
 {
 	u32 shared_buf_min, shared_buf_tc, shared_std;
-	int tc_num, pfc_enable_num;
+	int tc_num = hclge_get_tc_num(hdev);
 	u32 shared_buf, aligned_mps;
 	u32 rx_priv;
 	int i;
 
-	tc_num = hclge_get_tc_num(hdev);
-	pfc_enable_num = hclge_get_pfc_enalbe_num(hdev);
 	aligned_mps = roundup(hdev->mps, HCLGE_BUF_SIZE_UNIT);
 
 	if (hnae3_dev_dcb_supported(hdev))
@@ -1522,9 +1509,7 @@ static bool  hclge_is_rx_buf_ok(struct h
 		shared_buf_min = aligned_mps + HCLGE_NON_DCB_ADDITIONAL_BUF
 					+ hdev->dv_buf_size;
 
-	shared_buf_tc = pfc_enable_num * aligned_mps +
-			(tc_num - pfc_enable_num) * aligned_mps / 2 +
-			aligned_mps;
+	shared_buf_tc = tc_num * aligned_mps + aligned_mps;
 	shared_std = roundup(max_t(u32, shared_buf_min, shared_buf_tc),
 			     HCLGE_BUF_SIZE_UNIT);
 
@@ -1546,14 +1531,8 @@ static bool  hclge_is_rx_buf_ok(struct h
 	}
 
 	for (i = 0; i < HCLGE_MAX_TC_NUM; i++) {
-		if ((hdev->hw_tc_map & BIT(i)) &&
-		    (hdev->tm_info.hw_pfc_map & BIT(i))) {
-			buf_alloc->s_buf.tc_thrd[i].low = aligned_mps;
-			buf_alloc->s_buf.tc_thrd[i].high = 2 * aligned_mps;
-		} else {
-			buf_alloc->s_buf.tc_thrd[i].low = 0;
-			buf_alloc->s_buf.tc_thrd[i].high = aligned_mps;
-		}
+		buf_alloc->s_buf.tc_thrd[i].low = aligned_mps;
+		buf_alloc->s_buf.tc_thrd[i].high = 2 * aligned_mps;
 	}
 
 	return true;