[U-Boot] [PATCH 07/11 v2] drivers/net/vsc9953: Add commands to manipulate the FDB for VSC9953

[Joe Hershberger]

Hi Codrin,

On Tue, Jun 30, 2015 at 8:31 AM, Codrin Constantin Ciubotariu
<codrin.ciubotariu at freescale.com> wrote:
> Hi Joe,
>
>> -----Original Message-----
>> From: Joe Hershberger [mailto:joe.hershberger at gmail.com]
>> Sent: Friday, June 26, 2015 1:39 AM
>> To: Ciubotariu Codrin Constantin-B43658
>> Cc: u-boot; Joe Hershberger; Sun York-R58495
>> Subject: Re: [U-Boot] [PATCH 07/11 v2] drivers/net/vsc9953: Add commands to
>> manipulate the FDB for VSC9953
>>
>> > +       return !!timeout;
>>
>> Maybe return -EBUSY like suggested in previous patch.
>
> Ok.
>
>> > +       /* write port and vid to get selected FDB entries */
>> > +       val = in_le32(&l2ana_reg->ana.anag_efil);
>> > +       if (port_no != VSC9953_CMD_PORT_ALL) {
>> > +               val = (val & ~CONFIG_VSC9953_AGE_PORT_MASK) |
>> > +                               CONFIG_VSC9953_AGE_PORT_EN |
>> > +                               field_set(port_no,
>> > +                                         CONFIG_VSC9953_AGE_PORT_MASK);
>>
>> Seems like a good place to use bitfield_replace() from
>> include/bitfield.h (or a new one that you add that uses the mask for
>> the shift).
>>
>> > +       }
>> > +       if (vid != VSC9953_CMD_VLAN_ALL) {
>> > +               val = (val & ~CONFIG_VSC9953_AGE_VID_MASK) |
>> > +                               CONFIG_VSC9953_AGE_VID_EN |
>> > +                               field_set(vid, CONFIG_VSC9953_AGE_VID_MASK);
>>
>> Same here.
>
> Ok.
>
>> > +               vlan = field_get(val & CONFIG_VSC9953_MAC_VID_MASK,
>> > +                                CONFIG_VSC9953_MAC_VID_MASK);
>>
>> It seems like masking off the val before shifting it would be better
>> implemented inside the field_get function (renamed and moved to
>> include/bitfield.h) instead of on each use.
>
> Yes, something like #define field_set(val, mask)           (((val) * ((mask) & ~((mask) << 1))) & mask) and
> #define field_get(val, mask)           ((val & mask) / ((mask) & ~((mask) << 1))).

The set seems the same as replace, just without any other bitfields to
preserve. You could just use replace and pass in 0 as the reg_val.

>> > +       out_le32(&l2ana_reg->ana_tables.mach_data,
>> > +                (mac[0] << 8) | (mac[1] << 0) |
>> > +                (field_set(vid, CONFIG_VSC9953_MACHDATA_VID_MASK) &
>> > +                                CONFIG_VSC9953_MACHDATA_VID_MASK));
>>
>> Why do you need to & with the mask again after field_set()?
>
> To assure that the shifted vid value is not higher than its mask. Adding the mask to the macro/inline function as described above should assure this.

OK. Maybe the existing bitfield_replace() should be updated to also
mask off the bitfield_val.

>> > +       /* check if MAC address is present */
>> > +       if (!parsed_cmd->mac_addr) {
>>
>> Use this:
>> +       if (is_valid_ethaddr(parsed_cmd->mac_addr)) {
>
> is_valid_ethaddr() returns false if the mac address is 00:00:00:00:00:00, but for the L2 Switch, this mac address is valid. Maybe is_broadcast_ethaddr()?

I'm not sure what criteria you intend to check for here, so I'm not
sure if that is appropriate.

>> > +       /* check if MAC address is present */
>> > +       if (!parsed_cmd->mac_addr) {
>>
>> Use this:
>> +       if (is_valid_ethaddr(parsed_cmd->mac_addr)) {
>
> Same as above.
>
>> > +/* check if the string has the format for a MAC address */
>> > +static int string_is_mac_addr(const char *mac)
>> > +{
>> > +       int                     i;
>> > +
>> > +       if (!mac)
>> > +               return 0;
>> > +
>> > +       for (i = 0; i < 6; i++) {
>> > +               if (!isxdigit(*mac) || !isxdigit(*(mac + 1)))
>> > +                       return 0;
>> > +               mac += 2;
>> > +               if (i != 5) {
>> > +                       if (*mac != ':' && *mac != '-')
>> > +                               return 0;
>> > +                       mac++;
>> > +               }
>> > +       }
>> > +
>> > +       if (*mac != '\0')
>> > +               return 0;
>> > +
>> > +       return 1;
>>
>> This functionality is already implemented in common/env_flags.c in the
>> _env_flags_validate_type() function. Maybe that implementation should
>> be extracted.  Another option is to make the eth_parse_enetaddr() in
>> net/eth.c return a status and then it can be used. Either way I don't
>> think it should be re-implemented here.
>
> Yes, I noticed that this function is already implemented, but with no access to it. I will see how I can use the one available.

Which path do you plan to take?

Thanks,
-Joe