Subject: Re: [RFC PATCH net-next 1/5] ixgbe: Add a RETA query command to VF-PF channel API

From: Vlad Zolotarov <[email-masked]>
Date: Tue, 30 Dec 2014 21:35:14 +0200

On 12/30/14 21:30, Jeff Kirsher wrote:
> On Tue, 2014-12-30 at 21:28 +0200, Vlad Zolotarov wrote:
>> On 12/30/14 21:21, Jeff Kirsher wrote:
>>> On Tue, Dec 30, 2014 at 8:30 AM, Vlad Zolotarov
>>> <[email-masked]> wrote:
>>>> 82599 VFs and PF share the same RSS redirection table (RETA). Therefore we
>>>> just return it for all VFs.
>>>>
>>>> RETA table is an array of 32 registers and the maximum number of registers
>>>> that may be delivered in a single VF-PF channel command is 15. Therefore
>>>> we will deliver the whole table in 3 steps: 12, 12 and 8 registers in each
>>>> step correspondingly. Thus this patch does the following:
>>>>
>>>>     - Adds a new API version (to specify a new commands set).
>>>>     - Adds the IXGBE_VF_GET_RETA_[0,1,2] commands to the VF-PF commands set.
>>>>
>>>> Signed-off-by: Vlad Zolotarov <[email-masked]>
>>>> ---
>>>>    drivers/net/ethernet/intel/ixgbe/ixgbe_mbx.h   |  6 +++++
>>>>    drivers/net/ethernet/intel/ixgbe/ixgbe_sriov.c | 35 ++++++++++++++++++++++++++
>>>>    2 files changed, 41 insertions(+)
>>>>
>>>> diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_mbx.h b/drivers/net/ethernet/intel/ixgbe/ixgbe_mbx.h
>>>> index a5cb755..c1123d9 100644
>>>> --- a/drivers/net/ethernet/intel/ixgbe/ixgbe_mbx.h
>>>> +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_mbx.h
>>>> @@ -73,6 +73,7 @@ enum ixgbe_pfvf_api_rev {
>>>>           ixgbe_mbox_api_10,      /* API version 1.0, linux/freebsd VF driver */
>>>>           ixgbe_mbox_api_20,      /* API version 2.0, solaris Phase1 VF driver */
>>>>           ixgbe_mbox_api_11,      /* API version 1.1, linux/freebsd VF driver */
>>>> +       ixgbe_mbox_api_12,      /* API version 1.2, linux/freebsd VF driver */
>>>>           /* This value should always be last */
>>>>           ixgbe_mbox_api_unknown, /* indicates that API version is not known */
>>>>    };
>>>> @@ -91,6 +92,11 @@ enum ixgbe_pfvf_api_rev {
>>>>    /* mailbox API, version 1.1 VF requests */
>>>>    #define IXGBE_VF_GET_QUEUES    0x09 /* get queue configuration */
>>>>
>>>> +/* mailbox API, version 1.2 VF requests */
>>>> +#define IXGBE_VF_GET_RETA_0    0x0a /* get RETA[0..11]  */
>>>> +#define IXGBE_VF_GET_RETA_1    0x0b /* get RETA[12..23] */
>>>> +#define IXGBE_VF_GET_RETA_2    0x0c /* get RETA[24..31] */
>>>> +
>>>>    /* GET_QUEUES return data indices within the mailbox */
>>>>    #define IXGBE_VF_TX_QUEUES     1       /* number of Tx queues supported */
>>>>    #define IXGBE_VF_RX_QUEUES     2       /* number of Rx queues supported */
>>>> diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_sriov.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_sriov.c
>>>> index c76ba90..84db1a5 100644
>>>> --- a/drivers/net/ethernet/intel/ixgbe/ixgbe_sriov.c
>>>> +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_sriov.c
>>>> @@ -427,6 +427,7 @@ static s32 ixgbe_set_vf_lpe(struct ixgbe_adapter *adapter, u32 *msgbuf, u32 vf)
>>>>    #endif /* CONFIG_FCOE */
>>>>                   switch (adapter->vfinfo[vf].vf_api) {
>>>>                   case ixgbe_mbox_api_11:
>>>> +               case ixgbe_mbox_api_12:
>>>>                           /*
>>>>                            * Version 1.1 supports jumbo frames on VFs if PF has
>>>>                            * jumbo frames enabled which means legacy VFs are
>>>> @@ -894,6 +895,7 @@ static int ixgbe_negotiate_vf_api(struct ixgbe_adapter *adapter,
>>>>           switch (api) {
>>>>           case ixgbe_mbox_api_10:
>>>>           case ixgbe_mbox_api_11:
>>>> +       case ixgbe_mbox_api_12:
>>>>                   adapter->vfinfo[vf].vf_api = api;
>>>>                   return 0;
>>>>           default:
>>>> @@ -917,6 +919,7 @@ static int ixgbe_get_vf_queues(struct ixgbe_adapter *adapter,
>>>>           switch (adapter->vfinfo[vf].vf_api) {
>>>>           case ixgbe_mbox_api_20:
>>>>           case ixgbe_mbox_api_11:
>>>> +       case ixgbe_mbox_api_12:
>>>>                   break;
>>>>           default:
>>>>                   return -1;
>>>> @@ -944,6 +947,29 @@ static int ixgbe_get_vf_queues(struct ixgbe_adapter *adapter,
>>>>           return 0;
>>>>    }
>>>>
>>>> +static int ixgbe_get_vf_reta(struct ixgbe_adapter *adapter,
>>>> +                            u32 *msgbuf, u32 vf, int reta_offset_dw,
>>>> +                            size_t dwords)
>>>> +{
>>>> +       struct ixgbe_hw *hw = &adapter->hw;
>>>> +       int i;
>>>> +       u32 *reta = &msgbuf[1];
>>>> +
>>>> +       /* verify the PF is supporting the correct API */
>>>> +       switch (adapter->vfinfo[vf].vf_api) {
>>>> +       case ixgbe_mbox_api_12:
>>>> +               break;
>>>> +       default:
>>>> +               return -EPERM;
>>>> +       }
>>> A switch statement is overkill for a single case.  It would be far
>>> simpler to just have
>>>
>>> if (adapter->vfinfo[vf].vf_api != ixgbe_mbox_api_12)
>>>           return -EPERM;
>>>
>>> Later on, if there are multiple API's or future API's that also
>>> support this, then we could move to a case statement.
>> I thought about it to but decided to make it future-proof. NP. Will make
>> it an "if" in a non-RFC series. Thanks.
>>
> Thanks fine, and if you CC me on the non-RFC series,

Sure thing I will! ;) After such a lightning fast review I'll CC u for 
all my future net patches! ;)

>   I will pick them up
> (and make sure that Greg Rose has a chance to review them).
Cool. Then I'll cook the series first think tomorrow morning.
Thanks a lot, Jeff