Re: [PATCHv2] net: Define enum for the bits used in features.

["Michał Mirosław" <mirqus@gmail.com>]

2011/5/25 Mahesh Bandewar <maheshb@google.com>:
> Little bit cleanup by defining enum for all bits used. Also use those enum
> values to redefine flags.
>
> Signed-off-by: Mahesh Bandewar <maheshb@google.com>
> ---
> Changes since v1:
>  Split the patch into two pieces.
>
>  include/linux/netdevice.h |  100 +++++++++++++++++++++++++++++++-------------
>  1 files changed, 70 insertions(+), 30 deletions(-)
>
> diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
> index ca333e7..b4520b2 100644
> --- a/include/linux/netdevice.h
> +++ b/include/linux/netdevice.h
> @@ -51,6 +51,7 @@
>  #ifdef CONFIG_DCB
>  #include <net/dcbnl.h>
>  #endif
> +#include <linux/netdev_features.h>

This should go to other part.

>  struct vlan_group;
>  struct netpoll_info;
> @@ -981,6 +982,49 @@ struct net_device_ops {
>  };
>
>  /*
> + * Net device feature bits; if you change something,
> + * also update netdev_features_strings[] in ethtool.c
> + */
> +enum netdev_features {
[...]

> +       RESERVED16_BIT,         /* the GSO_MASK reserved bit 16 */
> +       RESERVED17_BIT,         /* the GSO_MASK reserved bit 17 */
> +       RESERVED18_BIT,         /* the GSO_MASK reserved bit 18 */
> +       RESERVED19_BIT,         /* the GSO_MASK reserved bit 19 */
> +       RESERVED20_BIT,         /* the GSO_MASK reserved bit 20 */
> +       RESERVED21_BIT,         /* the GSO_MASK reserved bit 21 */
> +       RESERVED22_BIT,         /* the GSO_MASK reserved bit 22 */
> +       RESERVED23_BIT,         /* the GSO_MASK reserved bit 23 */

This could also define NETIF_F_GSO_SHIFT and name TSO and others.
Maybe like this:


NETIF_F_GSO_SHIFT, /* must == 16, for now */
GSO_RESERVED0_BIT = NETIF_F_GSO_SHIFT,
GSO_RESERVED1_BIT,
...
GSO_RESERVED7_BIT,
... (other bits)
> +       /* Add you bit above this */

your.

> +       ND_FEATURE_NUM_BITS,     /* (LAST VALUE) Total bits in use */

And here GSO aliases:

TSO_BIT = NETIF_F_GSO_SHIFT + SKB_GSO_TCPV4,
UFO_BIT = NETIF_F_GSO_SHIFT + SKB_GSO_UDP,
...

Afther this is done, I can convert the feature-names table in
ethtool.c to use C99 array assignments, so that no one else will trip
on a missing comma or wrong entries order there.

About the bit names: NETIF_F_xxx_BIT?

Best Regards,
Michał Mirosław