Subject: Re: [PATCH net-next v9 4/7] ixgbevf: Add a RETA query code

From: Alexander Duyck <[email-masked]>
Date: Mon, 30 Mar 2015 07:58:05 -0700

On 03/30/2015 02:12 AM, Vlad Zolotarov wrote:
>
>
> On 03/30/15 01:51, Alexander Duyck wrote:
>> On 03/29/2015 09:11 AM, Vlad Zolotarov wrote:
>>> We will currently support only 82599 and x540 deviced. Support for 
>>> other devices
>>> will be added later.
>>>
>>>     - Added a new API version support.
>>>     - Added the query implementation in the ixgbevf.
>>>
>>> Signed-off-by: Vlad Zolotarov <[email-masked]>
>>> ---
>>> New in v9:
>>>     - Reduce the support to 82599 and x540 devices only.
>>>     - Improvements in RETA query code:
>>>        - Implement a "compression" of VF's RETA contents: pass only 
>>> 2 bits
>>>          per-entry.
>>>        - RETA querying is done in a single mailbox operation thanks 
>>> to compression.
>>>
>>> New in v8:
>>>     - Protect mailbox with a spinlock.
>>>
>>> New in v7:
>>>     - Add ixgbe_mbox_api_12 case in ixgbevf_set_num_queues().
>>>     - Properly expand HW RETA into the ethtool buffer.
>>>
>>> New in v6:
>>>     - Add a proper return code when an operation is blocked by PF.
>>>
>>> New in v3:
>>>     - Adjusted to the new interface IXGBE_VF_GET_RETA command.
>>>     - Added a proper support for x550 devices.
>>>
>>> New in v1 (compared to RFC):
>>>     - Use "if-else" statement instead of a "switch-case" for a 
>>> single option case
>>>       (in ixgbevf_get_reta()).
>>> ---
>>>   drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c |  5 +-
>>>   drivers/net/ethernet/intel/ixgbevf/mbx.h          |  4 ++
>>>   drivers/net/ethernet/intel/ixgbevf/vf.c           | 76 
>>> +++++++++++++++++++++++
>>>   drivers/net/ethernet/intel/ixgbevf/vf.h           |  2 +
>>>   4 files changed, 86 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c 
>>> b/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c
>>> index 4ee15ad..a16d267 100644
>>> --- a/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c
>>> +++ b/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c
>>> @@ -2030,7 +2030,8 @@ static void 
>>> ixgbevf_init_last_counter_stats(struct ixgbevf_adapter *adapter)
>>>   static void ixgbevf_negotiate_api(struct ixgbevf_adapter *adapter)
>>>   {
>>>       struct ixgbe_hw *hw = &adapter->hw;
>>> -    int api[] = { ixgbe_mbox_api_11,
>>> +    int api[] = { ixgbe_mbox_api_12,
>>> +              ixgbe_mbox_api_11,
>>>                 ixgbe_mbox_api_10,
>>>                 ixgbe_mbox_api_unknown };
>>>       int err = 0, idx = 0;
>>> @@ -2332,6 +2333,7 @@ static void ixgbevf_set_num_queues(struct 
>>> ixgbevf_adapter *adapter)
>>>             switch (hw->api_version) {
>>>           case ixgbe_mbox_api_11:
>>> +        case ixgbe_mbox_api_12:
>>>               adapter->num_rx_queues = rss;
>>>               adapter->num_tx_queues = rss;
>>>           default:
>>> @@ -3712,6 +3714,7 @@ static int ixgbevf_change_mtu(struct 
>>> net_device *netdev, int new_mtu)
>>>         switch (adapter->hw.api_version) {
>>>       case ixgbe_mbox_api_11:
>>> +    case ixgbe_mbox_api_12:
>>>           max_possible_frame = IXGBE_MAX_JUMBO_FRAME_SIZE;
>>>           break;
>>>       default:
>>> diff --git a/drivers/net/ethernet/intel/ixgbevf/mbx.h 
>>> b/drivers/net/ethernet/intel/ixgbevf/mbx.h
>>> index 6253e93..66e138b 100644
>>> --- a/drivers/net/ethernet/intel/ixgbevf/mbx.h
>>> +++ b/drivers/net/ethernet/intel/ixgbevf/mbx.h
>>> @@ -83,6 +83,7 @@ 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 */
>>>   };
>>> @@ -107,6 +108,9 @@ enum ixgbe_pfvf_api_rev {
>>>   #define IXGBE_VF_TRANS_VLAN    3 /* Indication of port VLAN */
>>>   #define IXGBE_VF_DEF_QUEUE    4 /* Default queue offset */
>>>   +/* mailbox API, version 1.2 VF requests */
>>> +#define IXGBE_VF_GET_RETA    0x0a    /* VF request for RETA */
>>> +
>>>   /* length of permanent address message returned from PF */
>>>   #define IXGBE_VF_PERMADDR_MSG_LEN    4
>>>   /* word in permanent address message with the current multicast 
>>> type */
>>> diff --git a/drivers/net/ethernet/intel/ixgbevf/vf.c 
>>> b/drivers/net/ethernet/intel/ixgbevf/vf.c
>>> index 2614fd3..2676c0b 100644
>>> --- a/drivers/net/ethernet/intel/ixgbevf/vf.c
>>> +++ b/drivers/net/ethernet/intel/ixgbevf/vf.c
>>> @@ -256,6 +256,81 @@ static s32 ixgbevf_set_uc_addr_vf(struct 
>>> ixgbe_hw *hw, u32 index, u8 *addr)
>>>       return ret_val;
>>>   }
>>>   +static inline int ixgbevf_get_reta_locked(struct ixgbe_hw *hw, 
>>> u32 *msgbuf,
>>> +                      u32 *reta)
>>> +{
>>> +    int err, i, j;
>>> +    u32 *hw_reta = &msgbuf[1];
>>> +
>>> +    /* We have to use a mailbox for 82599 and x540 devices only.
>>> +     * For these devices RETA has 128 entries.
>>> +     * Also these VFs support up to 4 RSS queues. Therefore PF will 
>>> compress
>>> +     * 16 RETA entries in each DWORD giving 2 bits to each entry.
>>> +     */
>>> +    int dwords = 128 / 16;
>>> +
>>> +    msgbuf[0] = IXGBE_VF_GET_RETA;
>>> +
>>> +    err = hw->mbx.ops.write_posted(hw, msgbuf, 1);
>>> +
>>> +    if (err)
>>> +        return err;
>>> +
>>> +    err = hw->mbx.ops.read_posted(hw, msgbuf, dwords + 1);
>>> +
>>> +    if (err)
>>> +        return err;
>>> +
>>> +    msgbuf[0] &= ~IXGBE_VT_MSGTYPE_CTS;
>>> +
>>> +    /* If the operation has been refused by a PF return -EPERM */
>>> +    if (msgbuf[0] == (IXGBE_VF_GET_RETA | IXGBE_VT_MSGTYPE_NACK))
>>> +        return -EPERM;
>>> +
>>> +    /* If we didn't get an ACK there must have been
>>> +     * some sort of mailbox error so we should treat it
>>> +     * as such.
>>> +     */
>>> +    if (msgbuf[0] != (IXGBE_VF_GET_RETA | IXGBE_VT_MSGTYPE_ACK))
>>> +        return IXGBE_ERR_MBX;
>>> +
>>> +    for (i = 0; i < dwords; i++)
>>> +        for (j = 0; j < 16; j++)
>>> +            reta[i * 16 + j] = (hw_reta[i] >> (2 * j)) & 0x3;
>>> +
>>> +    return 0;
>>> +}
>>> +
>>> +/**
>>> + * ixgbevf_get_reta - get the RSS redirection table (RETA) contents.
>>> + * @adapter: pointer to the port handle
>>> + * @reta: buffer to fill with RETA contents.
>>> + *
>>> + * The "reta" buffer should be big enough to contain 32 registers.
>>> + *
>>> + * Returns: 0 on success.
>>> + *          if API doesn't support this operation - (-EPERM).
>>> + */
>>> +int ixgbevf_get_reta(struct ixgbevf_adapter *adapter, u32 *reta)
>>> +{
>>> +    int err;
>>> +    u32 msgbuf[IXGBE_VFMAILBOX_SIZE];
>>> +
>>> +    /* We support the RSS querying for 82599 and x540 devices only.
>>> +     * Thus return an error if API doesn't support RETA querying or 
>>> querying
>>> +     * is not supported for this device type.
>>> +     */
>>> +    if (adapter->hw.api_version != ixgbe_mbox_api_12 ||
>>> +        adapter->hw.mac.type >= ixgbe_mac_X550_vf)
>>> +        return -EPERM;
>
> By the way, since u've commented on the return codes in PATCH02 don't 
> u think that we should return -EOPNOTSUPP here too?

Yes.  I just missed that in the review.  Though I don't know if 
EOPNOTSUPP is the correct response here since this is really meant to be 
an OS agnostic section.  You might just return IXGBE_ERR_MBX since there 
isn't a mailbox messages supported for x550_vf or API before 12.

- Alex