Re: [PATCH 1/3] netdev: introduce new NETIF_F_HW_SWITCH_OFFLOAD feature flag for switch device offloads

[Roopa Prabhu <roopa@cumulusnetworks.com>]

On 12/4/14, 7:21 PM, Jianhua Xie wrote:
>
> 在 2014年12月05日 10:26, roopa@cumulusnetworks.com 写道:
>> From: Roopa Prabhu <roopa@cumulusnetworks.com>
>>
>> This is a generic high level feature flag for all switch asic 
>> features today.
>>
>> switch drivers set this flag on switch ports. Logical devices like
>> bridge, bonds, vxlans can inherit this flag from their slaves/ports.
>>
>> I had to use SWITCH in the name to avoid ambiguity with other feature
>> flags. But, since i have been harping about not calling it 'switch',
>> I am welcome to any suggestions :)
>>
>> An alternative to using a feature flag is to use a IFF_HW_OFFLOAD
>> in net_device_flags.
>> ---
>>   include/linux/netdev_features.h |    2 ++
>>   1 file changed, 2 insertions(+)
>>
>> diff --git a/include/linux/netdev_features.h 
>> b/include/linux/netdev_features.h
>> index 8e30685..68db1de 100644
>> --- a/include/linux/netdev_features.h
>> +++ b/include/linux/netdev_features.h
>> @@ -66,6 +66,7 @@ enum {
>>       NETIF_F_HW_VLAN_STAG_FILTER_BIT,/* Receive filtering on VLAN 
>> STAGs */
>>       NETIF_F_HW_L2FW_DOFFLOAD_BIT,    /* Allow L2 Forwarding in 
>> Hardware */
>>       NETIF_F_BUSY_POLL_BIT,        /* Busy poll */
>> +    NETIF_F_HW_SWITCH_OFFLOAD_BIT,  /* HW switch offload */
> I am interested in this flag very much, but I am not very clear
> how many offload capabilities does this flag imply.  If this flag
> belongs to a general flag and can be accepted by all vendors,
> I will reuse this flag to introduce another out going data traffics
> distribution offload method to bonding driver.
Right now its a one global offload flag for switch asics. Some may not 
want to tune it more. But others may and so i do expect more flags in 
this category.

Thanks,
Roopa