Re: [PATCH net-next V2 09/12] net/mlx5_core: Make ipv4/ipv6 location more clear

[Matan Barak <matanb@mellanox.com>]

On 1/11/2016 2:17 PM, David Laight wrote:
> From: Or Gerlitz
>> Sent: 10 January 2016 08:40
>> Change the mlx5 firmware interface header to make it
>> more clear which bytes should be used by IPv4 or
>> IPv6 addresses.
>>
>> Signed-off-by: Maor Gottlieb <maorg@mellanox.com>
>> Signed-off-by: Moni Shoua <monis@mellanox.com>
>> Signed-off-by: Matan Barak <matanb@mellanox.com>
>> ---
>>   include/linux/mlx5/mlx5_ifc.h | 20 ++++++++++++++++++--
>>   1 file changed, 18 insertions(+), 2 deletions(-)
>>
>> diff --git a/include/linux/mlx5/mlx5_ifc.h b/include/linux/mlx5/mlx5_ifc.h
>> index 7f16695..68d73f8 100644
>> --- a/include/linux/mlx5/mlx5_ifc.h
>> +++ b/include/linux/mlx5/mlx5_ifc.h
>> @@ -298,6 +298,22 @@ struct mlx5_ifc_odp_per_transport_service_cap_bits {
>>   	u8         reserved_1[0x1a];
>>   };
>>
>> +struct mlx5_ifc_ipv4_layout_bits {
>> +	u8         reserved_0[0x60];
>> +
>> +	u8         ipv4[0x20];
>> +};
>> +
>> +struct mlx5_ifc_ipv6_layout_bits {
>> +	u8         ipv6[16][0x8];
>> +};
>> +
>> +union mlx5_ifc_ipv6_layout_ipv4_layout_auto_bits {
>> +	struct mlx5_ifc_ipv6_layout_bits ipv6_layout;
>> +	struct mlx5_ifc_ipv4_layout_bits ipv4_layout;
>> +	u8         reserved_0[0x80];
>> +};
>
> I like the way these names just roll off the tongue :-)
>
>> +
>>   struct mlx5_ifc_fte_match_set_lyr_2_4_bits {
>>   	u8         smac_47_16[0x20];
>>
>> @@ -328,9 +344,9 @@ struct mlx5_ifc_fte_match_set_lyr_2_4_bits {
>>   	u8         udp_sport[0x10];
>>   	u8         udp_dport[0x10];
>>
>> -	u8         src_ip[4][0x20];
>> +	union mlx5_ifc_ipv6_layout_ipv4_layout_auto_bits src_ipv4_src_ipv6;
>>
>> -	u8         dst_ip[4][0x20];
>> +	union mlx5_ifc_ipv6_layout_ipv4_layout_auto_bits dst_ipv4_dst_ipv6;
>>   };
>
> Have you considered just how long the line of code to access these
> fields will be?
> It might be better to do (I think it compiles):
> 	union {
> 		u8	src_ipv6[16][0x8];
> 		struct {
> 			u8	src_ipv4_pad[0x60];
> 			u8	src_ipv4[0x20];
> 		}
> 	};
> Repeated for the 'dst' addresses.
> Then fixup the definition of src_ipv4[] (and probably src_ipv6[]) to
> be much clearer about how the addresses are supplied.
>

This is actually created automatically, but I fully agree the names here 
look odd (to say the least). We'll of course fix that :)
Thanks for taking a look.

> 	David
>

Regards,
Matan