net: hns: Fix to adjust buf_size of ring according to mtu

Because buf_size of ring set to 2048, the process of rx_poll_one
can reuse the page, therefore the performance of XGE can improve.
But the chip only supports three bds in one package, so the max mtu
is 6K when it sets to 2048. For better performane in litter mtu, we
need change buf_size according to mtu.

When user change mtu, hns is only change the desc in memory. There
are some desc has been fetched by the chip, these desc can not be
changed by the code. So it needs set the port loopback and send
some packages to let the chip consumes the wrong desc and fetch new
desc.
Because the Pv660 do not support rss indirection, we need add version
check in mtu change process.

Signed-off-by: lipeng <lipeng321@huawei.com>
reviewed-by: Yisen Zhuang <yisen.zhuang@huawei.com>
Signed-off-by: Salil Mehta <salil.mehta@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 25 insertions, 1 deletions

diff --git a/drivers/net/ethernet/hisilicon/hns/hns_ae_adapt.c b/drivers/net/ethernet/hisilicon/hns/hns_ae_adapt.c
index 0a9cdf00b31a..cd7e88e433b6 100644
--- a/drivers/net/ethernet/hisilicon/hns/hns_ae_adapt.c
+++ b/drivers/net/ethernet/hisilicon/hns/hns_ae_adapt.c
@@ -267,8 +267,32 @@ static int hns_ae_clr_multicast(struct hnae_handle *handle)
 static int hns_ae_set_mtu(struct hnae_handle *handle, int new_mtu)
 {
 	struct hns_mac_cb *mac_cb = hns_get_mac_cb(handle);
+	struct hnae_queue *q;
+	u32 rx_buf_size;
+	int i, ret;
+
+	/* when buf_size is 2048, max mtu is 6K for rx ring max bd num is 3. */
+	if (!AE_IS_VER1(mac_cb->dsaf_dev->dsaf_ver)) {
+		if (new_mtu <= BD_SIZE_2048_MAX_MTU)
+			rx_buf_size = 2048;
+		else
+			rx_buf_size = 4096;
+	} else {
+		rx_buf_size = mac_cb->dsaf_dev->buf_size;
+	}
+
+	ret = hns_mac_set_mtu(mac_cb, new_mtu, rx_buf_size);
 
-	return hns_mac_set_mtu(mac_cb, new_mtu);
+	if (!ret) {
+		/* reinit ring buf_size */
+		for (i = 0; i < handle->q_num; i++) {
+			q = handle->qs[i];
+			q->rx_ring.buf_size = rx_buf_size;
+			hns_rcb_set_rx_ring_bs(q, rx_buf_size);
+		}
+	}
+
+	return ret;
 }
 
 static void hns_ae_set_tso_stats(struct hnae_handle *handle, int enable)