Subject: Re: [PATCH net-next v7 3/7] ixgbe: Add a RETA query command to VF-PF channel API

From: Vlad Zolotarov <[email-masked]>
Date: Wed, 25 Mar 2015 21:29:44 +0200

On 03/25/15 20:03, Tantilov, Emil S wrote:
>> -----Original Message-----
>> From: [email-masked] [mailto:[email-masked]] On Behalf Of Vlad Zolotarov
>> Sent: Tuesday, March 24, 2015 6:06 AM
>> Subject: [PATCH net-next v7 3/7] ixgbe: Add a RETA query command to VF-PF channel API
>>
>> 82599 and x540 VFs and PF share the same RSS redirection table (RETA). Therefore we
>> just return it for all VFs. x550 on the other hand provides a separate redirection
>> table for each VF (there is a per-pool RETA table).
>>
>> For 82599 and x540 RETA table is an array of 32 registers (128 bytes) 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.
>>
>> For x550 VFs RETA is a 64 byte array, so we may deliver it in two steps: 12 and 4 registers
>> correspondingly.
>>
>> Thus this patch does the following:
>>
>>   - Adds a new API version (to specify a new commands set).
>>   - Adds the IXGBE_VF_GET_RETA command to the VF-PF commands set.
>>
>> Signed-off-by: Vlad Zolotarov <[email-masked]>
>> ---
> <snip>
>
> +static int ixgbe_get_vf_reta(struct ixgbe_adapter *adapter, u32 *msgbuf, u32 vf)
> +{
> +	struct ixgbe_hw *hw = &adapter->hw;
> +	int i, j;
> +	u32 *reta = &msgbuf[1];
> +	u32 mask = 0;
> +	u32 psrtype;
> +	u32 reta_offset_dw = msgbuf[IXGBE_VF_RETA_OFFSET];
> +	u32 dwords = msgbuf[IXGBE_VF_RETA_SZ];
> +
> +	/* verify the PF is supporting the correct API */
> +	if (!adapter->vfinfo[vf].rss_query_enabled ||
> +	    (adapter->vfinfo[vf].vf_api != ixgbe_mbox_api_12))
> +		return -EPERM;
> +
> +	psrtype = IXGBE_READ_REG(hw, IXGBE_PSRTYPE(vf));
> +
> +	/* The redirection table is composed as follows:
> +	 * 82598: 128 (8 bit wide) entries containing pair of 4 bit RSS indices
> +	 * 82599/X540: 128 (8 bit wide) entries containing 4 bit RSS index X550:
> +	 * 512 (8 bit wide) entries containing 6 bit RSS index
> +	 *
> +	 * PSRTYPE[n].RQPL defines if 0, 1 or 2 bits from the redirection table
> +	 * value should be used.
> +	 */
> +
> +	if ((psrtype & (1 << 29)) == (1 << 29))
> +		mask = 0x01010101;
> +	else if ((psrtype & (2 << 29)) == (2 << 29))
> +		mask = 0x03030303;
> +	else
> +		mask = 0;
> +
> +	switch (hw->mac.type) {
> +	case ixgbe_mac_82599EB:
> +	case ixgbe_mac_X540:
> +		/* Read the appropriate portion of RETA */
> +		for (i = 0; i < dwords; i++)
> +			reta[i] = IXGBE_READ_REG(hw,
> +						IXGBE_RETA(i + reta_offset_dw));
> +		break;
> +	case ixgbe_mac_X550:
> +	case ixgbe_mac_X550EM_x:
> +		/* X550 has a per-VF RETA */
> +		for (i = 0, j = reta_offset_dw; i < dwords; i++, j++)
> +			reta[i] = IXGBE_READ_REG(hw,
> +						IXGBE_PFVFRETA(j, vf));
> +		break;
> +	default:
> +		return -1;
>
> There is no need to query the X550 info through the mailbox - this information can be obtained directly from the VF registers.

I couldn't find an x550 spec anywhere. Could u tell me where it may be found?

> Thanks,
> Emil