Re: [PATCH v2 for-next] RDMA/core: Get IB width and speed from netdev

Leon Romanovsky
2023-06-11T17:46:15Z

On Sat, Jun 03, 2023 at 02:38:33PM +0800, Junxian Huang wrote:
> From: Haoyue Xu <xuhaoyue1@hisilicon.com>
>
> Previously, there was no way to query the number of lanes for a network
> card, so the same netdev_speed would result in a fixed pair of width and
> speed. As network card specifications become more diverse, such fixed
> mode is no longer suitable, so a method is needed to obtain the correct
> width and speed based on the number of lanes.

I'm sorry but I didn't understand the problem statement. Can you please
provide an example of configuration that will give different results
before this patch and after?

>
> This patch retrieves netdev lanes and speed from net_device and
> translates them to IB width and speed. Also, add a generic function
> to translating netdev speed to IB speed.
>
> Signed-off-by: Haoyue Xu <xuhaoyue1@hisilicon.com>
> Signed-off-by: Luoyouming <luoyouming@huawei.com>
> Signed-off-by: Junxian Huang <huangjunxian6@hisilicon.com>
> ---
> drivers/infiniband/core/verbs.c | 19 +++++++++++++++++--
> include/rdma/ib_verbs.h | 26 ++++++++++++++++++++++++++
> 2 files changed, 43 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/infiniband/core/verbs.c b/drivers/infiniband/core/verbs.c
> index b99b3cc283b6..35f1b670600a 100644
> --- a/drivers/infiniband/core/verbs.c
> +++ b/drivers/infiniband/core/verbs.c
> @@ -1880,11 +1880,19 @@ int ib_modify_qp_with_udata(struct ib_qp *ib_qp, struct ib_qp_attr *attr,
> }
> EXPORT_SYMBOL(ib_modify_qp_with_udata);
>
> +static void ib_get_width_and_speed(u32 netdev_speed, u32 lanes,
> + u16 *speed, u8 *width)
> +{
> + *width = ib_int_to_ib_width(lanes);
> + *speed = ib_eth_to_ib_speed(netdev_speed / lanes);
> +}
> +
> int ib_get_eth_speed(struct ib_device *dev, u32 port_num, u16 *speed, u8 *width)
> {
> int rc;
> u32 netdev_speed;
> struct net_device *netdev;
> + bool cap_link_lanes_supported;
> struct ethtool_link_ksettings lksettings;
>
> if (rdma_port_get_link_layer(dev, port_num) != IB_LINK_LAYER_ETHERNET)
> @@ -1896,16 +1904,23 @@ int ib_get_eth_speed(struct ib_device *dev, u32 port_num, u16 *speed, u8 *width)
>
> rtnl_lock();
> rc = __ethtool_get_link_ksettings(netdev, &lksettings);
> + cap_link_lanes_supported = netdev->ethtool_ops->cap_link_lanes_supported;
> rtnl_unlock();
>
> dev_put(netdev);
>
> if (!rc && lksettings.base.speed != (u32)SPEED_UNKNOWN) {
> netdev_speed = lksettings.base.speed;
> + if (cap_link_lanes_supported && lksettings.lanes) {

According to the documentation cap_link_lanes_supported defines if
number of lanes can be supplied by user and I would expect from
__ethtool_get_link_ksettings() to get right numbers after it was
changed.

Thanks

> + ib_get_width_and_speed(netdev_speed, lksettings.lanes,
> + speed, width);
> + return 0;
> + }
> } else {
> netdev_speed = SPEED_1000;
> - pr_warn("%s speed is unknown, defaulting to %u\n", netdev->name,
> - netdev_speed);
> + if (rc)
> + pr_warn("%s speed is unknown, defaulting to %u\n",
> + netdev->name, netdev_speed);
> }
>
> if (netdev_speed <= SPEED_1000) {
> diff --git a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h
> index 1e7774ac808f..7dc926ec7fee 100644
> --- a/include/rdma/ib_verbs.h
> +++ b/include/rdma/ib_verbs.h
> @@ -552,6 +552,18 @@ static inline int ib_width_enum_to_int(enum ib_port_width width)
> }
> }
>
> +static inline int ib_int_to_ib_width(u32 lanes)
> +{
> + switch (lanes) {
> + case 1: return IB_WIDTH_1X;
> + case 2: return IB_WIDTH_2X;
> + case 4: return IB_WIDTH_4X;
> + case 8: return IB_WIDTH_8X;
> + case 12: return IB_WIDTH_12X;
> + default: return IB_WIDTH_1X;
> + }
> +}
> +
> enum ib_port_speed {
> IB_SPEED_SDR = 1,
> IB_SPEED_DDR = 2,
> @@ -563,6 +575,20 @@ enum ib_port_speed {
> IB_SPEED_NDR = 128,
> };
>
> +static inline int ib_eth_to_ib_speed(u32 speed)
> +{
> + switch (speed) {
> + case SPEED_2500: return IB_SPEED_SDR;
> + case SPEED_5000: return IB_SPEED_DDR;
> + case SPEED_10000: return IB_SPEED_FDR10;
> + case SPEED_14000: return IB_SPEED_FDR;
> + case SPEED_25000: return IB_SPEED_EDR;
> + case SPEED_50000: return IB_SPEED_HDR;
> + case SPEED_100000: return IB_SPEED_NDR;
> + default: return IB_SPEED_SDR;
> + }
> +}
> +
> enum ib_stat_flag {
> IB_STAT_FLAG_OPTIONAL = 1 << 0,
> };
> --
> 2.30.0
>