Re: [PATCH 3/4] net: dsa: Add support for SoC-e SDSA tags

[Andrew Lunn <andrew@lunn.ch>]

> @@ -98,6 +98,12 @@ config NET_DSA_TAG_EDSA
>  	  Say Y or M if you want to enable support for tagging frames for the
>  	  Marvell switches which use EtherType DSA headers.
>  
> +config NET_DSA_TAG_SDSA
> +	tristate "Tag driver for SoC-e switches using EtherType SDSA headers"
> +	help
> +	  Say Y or M if you want to enable support for tagging frames for the
> +	  SoC-e switches.
> +

These entries are sorted, so it probably should be between
NET_DSA_TAG_RZN1_A5PSW and NET_DSA_TAG_LAN9303.

> @@ -23,6 +23,7 @@ dsa_core-y += \
>  obj-$(CONFIG_NET_DSA_TAG_AR9331) += tag_ar9331.o
>  obj-$(CONFIG_NET_DSA_TAG_BRCM_COMMON) += tag_brcm.o
>  obj-$(CONFIG_NET_DSA_TAG_DSA_COMMON) += tag_dsa.o
> +obj-$(CONFIG_NET_DSA_TAG_SDSA) += tag_sdsa.o
>  obj-$(CONFIG_NET_DSA_TAG_GSWIP) += tag_gswip.o

Also sorted, and this is the wrong spot.

> +#define SDSA_HLEN	8
> +
> +#define SDSA_NAME	"sdsa"

Does SDSA mean anything? Or have you taken net/dsa/tag_dsa.c, and just
changed edsa to sdsa?

> +static struct sk_buff *sdsa_xmit(struct sk_buff *skb, struct net_device *dev)
> +{
> +	struct dsa_port *dp = dsa_user_to_port(dev);
> +	u8 *sdsa_header;
> +
> +	if (skb_cow_head(skb, SDSA_HLEN) < 0)
> +		return NULL;
> +
> +	skb_push(skb, SDSA_HLEN);
> +	dsa_alloc_etype_header(skb, SDSA_HLEN);
> +
> +	/* Construct the FROM_CPU DSA tag. */

Is FROM_CPU a concept for this device? Are there other types of tag?

> +	sdsa_header = dsa_etype_header_pos_tx(skb);
> +	sdsa_header[0] = (ETH_P_SDSA >> 8) & 0xff;
> +	sdsa_header[1] = ETH_P_SDSA & 0xff;
> +	sdsa_header[2] = 0x00; /* reserved */
> +	sdsa_header[3] = 0x00; /* reserved */
> +	sdsa_header[4] = FIELD_PREP(SDSA_TAG_FRAME_TYPE_MASK, 1) |
> +			 FIELD_PREP(SDSA_TAG_PORT_HI_MASK, dp->index >> 5);
> +	sdsa_header[5] = FIELD_PREP(SDSA_TAG_PORT_MASK, dp->index);
> +	sdsa_header[6] = 0x00; /* VLAN not supported */
> +	sdsa_header[7] = 0x00; /* VLAN not supported */
> +
> +	return skb;
> +}
> +
> +static struct sk_buff *sdsa_rcv(struct sk_buff *skb, struct net_device *dev)
> +{
> +	u8 *sdsa_header;
> +	int source_port;
> +	u8 frame_type;
> +
> +	if (unlikely(!pskb_may_pull(skb, SDSA_HLEN)))
> +		return NULL;
> +
> +	sdsa_header = dsa_etype_header_pos_rx(skb);
> +
> +	/* Check that the frame type is TO_CPU. */
> +	frame_type = FIELD_GET(SDSA_TAG_FRAME_TYPE_MASK, sdsa_header[4]);
> +	if (frame_type != 0)

#define for TO_CPU?

	Andrew