Re: [PATCH net-next 2/4] net-next: dsa: add Mediatek tag RX/TX handler

Florian Fainelli
2017-03-13T16:36:53Z

On 03/13/2017 09:11 AM, sean.wang@mediatek.com wrote:
> From: Sean Wang <sean.wang@mediatek.com>
>
> Add the support for the 4-bytes tag for DSA port distinguishing inserted
> allowing receiving and transmitting the packet via the particular port.
> The tag is being added after the source MAC address in the ethernet
> header.
>
> Signed-off-by: Sean Wang <sean.wang@mediatek.com>
> Signed-off-by: Landen Chao <Landen.Chao@mediatek.com>
> ---
> include/net/dsa.h | 1 +
> net/dsa/Kconfig | 2 +
> net/dsa/Makefile | 1 +
> net/dsa/dsa.c | 3 ++
> net/dsa/dsa_priv.h | 3 ++
> net/dsa/tag_mtk.c | 121 +++++++++++++++++++++++++++++++++++++++++++++++++++++
> 6 files changed, 131 insertions(+)
> create mode 100644 net/dsa/tag_mtk.c
>
> diff --git a/include/net/dsa.h b/include/net/dsa.h
> index b122196..954cff2 100644
> --- a/include/net/dsa.h
> +++ b/include/net/dsa.h
> @@ -27,6 +27,7 @@ enum dsa_tag_protocol {
> DSA_TAG_PROTO_EDSA,
> DSA_TAG_PROTO_BRCM,
> DSA_TAG_PROTO_QCA,
> + DSA_TAG_PROTO_MTK,
> DSA_TAG_LAST, /* MUST BE LAST */
> };
>
> diff --git a/net/dsa/Kconfig b/net/dsa/Kconfig
> index 96e47c5..43b67e8 100644
> --- a/net/dsa/Kconfig
> +++ b/net/dsa/Kconfig
> @@ -41,4 +41,6 @@ config NET_DSA_TAG_TRAILER
> config NET_DSA_TAG_QCA
> bool
>
> +config NET_DSA_TAG_MTK
> + bool
> endif
> diff --git a/net/dsa/Makefile b/net/dsa/Makefile
> index a3380ed..97c9891 100644
> --- a/net/dsa/Makefile
> +++ b/net/dsa/Makefile
> @@ -8,3 +8,4 @@ dsa_core-$(CONFIG_NET_DSA_TAG_DSA) += tag_dsa.o
> dsa_core-$(CONFIG_NET_DSA_TAG_EDSA) += tag_edsa.o
> dsa_core-$(CONFIG_NET_DSA_TAG_TRAILER) += tag_trailer.o
> dsa_core-$(CONFIG_NET_DSA_TAG_QCA) += tag_qca.o
> +dsa_core-$(CONFIG_NET_DSA_TAG_MTK) += tag_mtk.o
> diff --git a/net/dsa/dsa.c b/net/dsa/dsa.c
> index 7899919..3586b1e 100644
> --- a/net/dsa/dsa.c
> +++ b/net/dsa/dsa.c
> @@ -57,6 +57,9 @@ static struct sk_buff *dsa_slave_notag_xmit(struct sk_buff *skb,
> #ifdef CONFIG_NET_DSA_TAG_QCA
> [DSA_TAG_PROTO_QCA] = &qca_netdev_ops,
> #endif
> +#ifdef CONFIG_NET_DSA_TAG_MTK
> + [DSA_TAG_PROTO_MTK] = &mtk_dsa_netdev_ops,
> +#endif
> [DSA_TAG_PROTO_NONE] = &none_ops,
> };
>
> diff --git a/net/dsa/dsa_priv.h b/net/dsa/dsa_priv.h
> index 6cfd738..de61e8f 100644
> --- a/net/dsa/dsa_priv.h
> +++ b/net/dsa/dsa_priv.h
> @@ -84,4 +84,7 @@ int dsa_slave_netdevice_event(struct notifier_block *unused,
> /* tag_qca.c */
> extern const struct dsa_device_ops qca_netdev_ops;
>
> +/* tag_mtk.c */
> +extern const struct dsa_device_ops mtk_dsa_netdev_ops;
> +
> #endif
> diff --git a/net/dsa/tag_mtk.c b/net/dsa/tag_mtk.c
> new file mode 100644
> index 0000000..a2dc014
> --- /dev/null
> +++ b/net/dsa/tag_mtk.c
> @@ -0,0 +1,121 @@
> +/*
> + * Mediatek DSA Tag support
> + * Copyright (C) 2017 Landen Chao <landen.chao@mediatek.com>
> + * Sean Wang <sean.wang@mediatek.com>
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 and
> + * only version 2 as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + */
> +
> +#include <linux/etherdevice.h>
> +#include "dsa_priv.h"
> +
> +#define MTK_HDR_LEN 4
> +#define MTK_HDR_RECV_SOURCE_PORT_MASK GENMASK(2, 0)
> +#define MTK_HDR_XMIT_DP_BIT_MASK GENMASK(5, 0)
> +
> +static struct sk_buff *mtk_tag_xmit(struct sk_buff *skb,
> + struct net_device *dev)
> +{
> + struct dsa_slave_priv *p = netdev_priv(dev);
> + u8 *mtk_tag;
> +
> + if (skb_cow_head(skb, MTK_HDR_LEN) < 0)
> + goto out_free;
> +
> + skb_push(skb, MTK_HDR_LEN);
> +
> + memmove(skb->data, skb->data + MTK_HDR_LEN, 2 * ETH_ALEN);
> +
> + /* Build the tag after the MAC Source Address */
> + mtk_tag = skb->data + 2 * ETH_ALEN;
> +
> + /* Set the ingress opcode, traffic class, tag enforcment is
> + * deprecated
> + */

Sounds like this comment came from tag_brcm.c does it really apply here
as well?

Other than that:

Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
--
Florian