[PATCH v5 2/3] common/sfc_efx/base: add support to enable VLAN stripping

[Artemii Morozov]

On 6/19/23 14:28, Andrew Rybchenko wrote:

> On 6/13/23 18:12, Artemii Morozov wrote:
>> To enable VLAN stripping, two conditions must be met:
>> the corresponding flag must be set and the appropriate
>> RX prefix should be requested.
>
> RX -> Rx
>
>> VLAN stripping is supported for ef100 datapath only.
>
> "ef100 datapath" does not make sense in libefx.
> "VLAN stripping is supported on EF100 only."
> However, such string could be confusing in the future. So, I'd drop
> "only"
>
> LGTM, but the problem of the patch is that it does not ensure and does
> not highlight in any way that efx_port_vlan_strip_set() must be called
> before any filter insertion to have things consistent.

This function is called before the sfc_rx_default_rxq_set_filter


> efx_port_vlan_strip_set() should check that no filters are installed
> (directly or indirectly via default RxQ set).

I believe we have the following options:

1. Move the function efx_port_vlan_strip_set before filter 
initialization(efx_filter_init) and include the statement 
"EFSYS_ASSERT(!(enp->en_mod_flags & EFX_MOD_FILTER))" at the beginning 
of the efx_port_vlan_strip_set function.
2. Introduce a new callback function called 
efx_mac_filter_default_rxq_get. Invoke this function at the start of 
efx_port_vlan_strip_set and verify that it returns NULL.

I don't see any other ways to check that the default filters have been 
initialized. Could you advise me how to do it better? Am I missing 
something?

>
>> diff --git a/drivers/common/sfc_efx/base/efx_port.c 
>> b/drivers/common/sfc_efx/base/efx_port.c
>> index a5f982e335..7804eb76bc 100644
>> --- a/drivers/common/sfc_efx/base/efx_port.c
>> +++ b/drivers/common/sfc_efx/base/efx_port.c
>> @@ -204,6 +204,24 @@ efx_loopback_type_name(
>>     #endif    /* EFSYS_OPT_LOOPBACK */
>>   +    __checkReturn    efx_rc_t
>> +efx_port_vlan_strip_set(
>> +    __in        efx_nic_t *enp,
>> +    __in        boolean_t enabled)
>> +{
>> +    efx_port_t *epp = &(enp->en_port);
>> +    efx_nic_cfg_t *encp = &(enp->en_nic_cfg);
>> +
>> +    EFSYS_ASSERT3U(enp->en_magic, ==, EFX_NIC_MAGIC);
>> +
>> +    if (enabled && !encp->enc_rx_vlan_stripping_supported)
>> +        return ENOTSUP;
>
> Return value must be in parenthesis in libefx (common/sfc_efx/base).
>
>> +
>> +    epp->ep_vlan_strip = enabled;
>> +
>> +    return 0;
>
> Return value must be in parenthesis in libefx (common/sfc_efx/base).
>
>> +}
>> +
>>               void
>>   efx_port_fini(
>>       __in        efx_nic_t *enp)
>