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

[Sean Wang <sean.wang@mediatek.com>]

On Mon, 2017-03-13 at 09:35 -0700, Florian Fainelli wrote:
> 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:


It seem a copy-paste error accidentally , i will fix up them in the next
version.  The tag only carried port information only , not complicated
as tag_brcm.c is done.


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