On 10/17/2018 12:53 PM, Christian Lamparter wrote:
> As per' APM82181 Embedded Processor User Manual 26.1 EMAC Features:
> VLAN:
> - Support for VLAN tag ID in compliance with IEEE 802.3ac.
> - VLAN tag insertion or replacement for transmit packets
>
> This patch completes the missing code for the VLAN tx tagging
> support, as the the EMAC_MR1_VLE was already enabled.
>
> Signed-off-by: Christian Lamparter <chunk...@gmail.com>
> ---
> drivers/net/ethernet/ibm/emac/core.c | 32 ++++++++++++++++++++++++----
> drivers/net/ethernet/ibm/emac/core.h | 6 +++++-
> 2 files changed, 33 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/net/ethernet/ibm/emac/core.c
> b/drivers/net/ethernet/ibm/emac/core.c
> index 760b2ad8e295..be560f9031f4 100644
> --- a/drivers/net/ethernet/ibm/emac/core.c
> +++ b/drivers/net/ethernet/ibm/emac/core.c
> @@ -37,6 +37,7 @@
> #include <linux/ethtool.h>
> #include <linux/mii.h>
> #include <linux/bitops.h>
> +#include <linux/if_vlan.h>
> #include <linux/workqueue.h>
> #include <linux/of.h>
> #include <linux/of_address.h>
> @@ -674,7 +675,7 @@ static int emac_configure(struct emac_instance *dev)
> ndev->dev_addr[5]);
>
> /* VLAN Tag Protocol ID */
> - out_be32(&p->vtpid, 0x8100);
> + out_be32(&p->vtpid, ETH_P_8021Q);
>
> /* Receive mode register */
> r = emac_iff2rmr(ndev);
> @@ -1435,6 +1436,22 @@ static inline netdev_tx_t emac_xmit_finish(struct
> emac_instance *dev, int len)
> return NETDEV_TX_OK;
> }
>
> +static inline u16 emac_tx_vlan(struct emac_instance *dev, struct sk_buff
> *skb)
> +{
> + /* Handle VLAN TPID and TCI insert if this is a VLAN skb */
> + if (emac_has_feature(dev, EMAC_FTR_HAS_VLAN_CTAG_TX) &&
> + skb_vlan_tag_present(skb)) {
> + struct emac_regs __iomem *p = dev->emacp;
> +
> + /* update the VLAN TCI */
> + out_be32(&p->vtci, (u32)skb_vlan_tag_get(skb));
The only case where this is likely not going to be 0x8100/ETH_P_8021Q is
if you do 802.1ad (QinQ) and you decided to somehow offload the S-Tag
instead of the C-Tag.
It would be a shame to slow down your TX path with an expensive register
write, when maybe inserting the VLAN in software amounts to the same
performance result ;)
--
Florian
