Re: [PATCH RFC 00/12] RDMA: Support link status events dispatching in ib_core

[Leon Romanovsky <leon@kernel.org>]

On Wed, Dec 25, 2024 at 02:12:58PM +0800, Junxian Huang wrote:
> 
> 
> On 2024/12/24 21:38, Leon Romanovsky wrote:
> > On Tue, Dec 24, 2024 at 08:05:26PM +0800, Junxian Huang wrote:
> >>
> >>
> >> On 2024/12/24 18:32, Leon Romanovsky wrote:
> >>> On Fri, Nov 22, 2024 at 06:52:56PM +0800, Junxian Huang wrote:
> >>>> This series is to integrate a common link status event handler in
> >>>> ib_core as this functionality is needed by most drivers and
> >>>> implemented in very similar patterns. This is not a new issue but
> >>>> a restart of the previous work of our colleagues from several years
> >>>> ago, please see [1] and [2].
> >>>>
> >>>> [1]: https://lore.kernel.org/linux-rdma/1570184954-21384-1-git-send-email-liweihang@hisilicon.com/
> >>>> [2]: https://lore.kernel.org/linux-rdma/20200204082408.18728-1-liweihang@huawei.com/
> >>>>
> >>>> With this series, ib_core can handle netdev events of link status,
> >>>> i.e. NETDEV_UP, NETDEV_DOWN and NETDEV_CHANGE, and dispatch ib port
> >>>> events to ULPs instead of drivers. However some drivers currently
> >>>> have some private processing in their handler, rather than simply
> >>>> dispatching events. For these drivers, this series provides a new
> >>>> ops report_port_event(). If this ops is set, ib_core will call it
> >>>> and the events will still be handled in the driver.
> >>>>
> >>>> Events of LAG devices are also not handled in ib_core as currently
> >>>> there is no way to obtain ibdev from upper netdev in ib_core. This
> >>>> can be a TODO work after the core have more support for LAG. For
> >>>> now mlx5 is the only driver that supports RoCE LAG, and the events
> >>>> handling of mlx5 RoCE LAG will remain in mlx5 driver.
> >>>>
> >>>> In this series:
> >>>>
> >>>> Patch #1 adds a new helper to query the port num of a netdev
> >>>> associated with an ibdev. This is used in the following patch.
> >>>>
> >>>> Patch #2 adds support for link status events dispatching in ib_core.
> >>>>
> >>>> Patch #3-#7 removes link status event handler in several drivers.
> >>>> The port state setting in erdma, rxe and siw are replaced with
> >>>> ib_get_curr_port_state(), so their handler can be totally removed.
> >>>>
> >>>> Patch #8-#10 add support for report_port_event() ops in usnic, mlx4
> >>>> and pvrdma as their current handler cannot be perfectly replaced by
> >>>> the ib_core handler in patch #2.
> >>>>
> >>>> Patch #11 adds a check in mlx5 that only events of RoCE LAG will be
> >>>> handled in mlx5 driver.
> >>>>
> >>>> Patch #12 adds a fast path for link-down events dispatching in hns by
> >>>> getting notified from hns3 nic driver directly.
> >>>>
> >>>> Yuyu Li (12):
> >>>>   RDMA/core: Add ib_query_netdev_port() to query netdev port by IB
> >>>>     device.
> >>>>   RDMA/core: Support link status events dispatching
> >>>>   RDMA/bnxt_re: Remove deliver net device event
> >>>>   RDMA/erdma: Remove deliver net device event
> >>>>   RDMA/irdma: Remove deliver net device event
> >>>>   RDMA/rxe: Remove deliver net device event
> >>>>   RDMA/siw: Remove deliver net device event
> >>>>   RDMA/usnic: Support report_port_event() ops
> >>>>   RDMA/mlx4: Support report_port_event() ops
> >>>>   RDMA/pvrdma: Support report_port_event() ops
> >>>>   RDMA/mlx5: Handle link status event only for LAG device
> >>>>   RDMA/hns: Support fast path for link-down events dispatching
> >>>
> >>> I took the series as it is good thing to remove code duplication
> >>> and we waited enough.
> >>>
> >>
> >> Thanks Leon.
> >>
> >> The kernel test robot has reported one warning and one error for
> >> this series:
> >>
> >> https://lore.kernel.org/oe-kbuild-all/202411251625.VrcLuTRx-lkp@intel.com/
> >> https://lore.kernel.org/oe-kbuild-all/202411251727.RFxtcpiI-lkp@intel.com/
> >>
> >> I was planning to fix them when I could send the formal patches,
> >> but since you have applied these RFC patches，could you please
> >> fix them on your wip branch, or should I send separate patches
> >> to fix them?
> > 
> > This is how I fixed it. Is it ok?
> > 
> > diff --git a/drivers/infiniband/hw/bnxt_re/main.c b/drivers/infiniband/hw/bnxt_re/main.c
> > index 4286fd4a9324..b886fe2922ae 100644
> > --- a/drivers/infiniband/hw/bnxt_re/main.c
> > +++ b/drivers/infiniband/hw/bnxt_re/main.c
> > @@ -822,17 +822,6 @@ static void bnxt_re_disassociate_ucontext(struct ib_ucontext *ibcontext)
> >  }
> >  
> >  /* Device */
> > -
> > -static struct bnxt_re_dev *bnxt_re_from_netdev(struct net_device *netdev)
> > -{
> > -	struct ib_device *ibdev =
> > -		ib_device_get_by_netdev(netdev, RDMA_DRIVER_BNXT_RE);
> > -	if (!ibdev)
> > -		return NULL;
> > -
> > -	return container_of(ibdev, struct bnxt_re_dev, ibdev);
> > -}
> > -
> >  static ssize_t hw_rev_show(struct device *device, struct device_attribute *attr,
> >  			   char *buf)
> >  {
> > diff --git a/drivers/infiniband/hw/usnic/usnic_ib_main.c b/drivers/infiniband/hw/usnic/usnic_ib_main.c
> > index 5ad7fe7e662f..4ddcd5860e0f 100644
> > --- a/drivers/infiniband/hw/usnic/usnic_ib_main.c
> > +++ b/drivers/infiniband/hw/usnic/usnic_ib_main.c
> > @@ -192,10 +192,12 @@ static void usnic_ib_handle_usdev_event(struct usnic_ib_dev *us_ibdev,
> >  
> >  static void usnic_ib_handle_port_event(struct ib_device *ibdev,
> >  				       struct net_device *netdev,
> > -				       unsigned long event);
> > +				       unsigned long event)
> >  {
> >  	struct usnic_ib_dev *us_ibdev =
> >  			container_of(ibdev, struct usnic_ib_dev, ib_dev);
> > +	struct ib_event ib_event;
> > +
> >  	mutex_lock(&us_ibdev->usdev_lock);
> >  	switch (event) {
> >  	case NETDEV_UP:
> > diff --git a/drivers/infiniband/sw/siw/siw_verbs.c b/drivers/infiniband/sw/siw/siw_verbs.c
> > index 137819184b3b..6b24438df917 100644
> > --- a/drivers/infiniband/sw/siw/siw_verbs.c
> > +++ b/drivers/infiniband/sw/siw/siw_verbs.c
> > @@ -172,6 +172,7 @@ int siw_query_port(struct ib_device *base_dev, u32 port,
> >  		   struct ib_port_attr *attr)
> >  {
> >  	struct siw_device *sdev = to_siw_dev(base_dev);
> > +	struct net_device *ndev;
> >  	int rv;
> >  
> >  	memset(attr, 0, sizeof(*attr));
> > @@ -183,7 +184,12 @@ int siw_query_port(struct ib_device *base_dev, u32 port,
> >  	attr->max_mtu = ib_mtu_int_to_enum(sdev->netdev->mtu);
> >  	attr->active_mtu = ib_mtu_int_to_enum(sdev->netdev->mtu);
> >  	attr->port_cap_flags = IB_PORT_CM_SUP | IB_PORT_DEVICE_MGMT_SUP;
> > -	attr->state = ib_get_curr_port_state(sdev->ndev);
> > +	ndev = ib_device_get_netdev(base_dev, port);
> > +	if (ndev)
> > +		attr->state = ib_get_curr_port_state(ndev);
> > +	else
> > +		attr->state = IB_PORT_DOWN;
> > +	dev_put(ndev);
> 
> I think this is a simpler way:
> 
> attr->state = ib_get_curr_port_state(sdev->netdev);
> 
> But overall LGTM, thanks.
> 
> BTW, it seems the kernel test robot has reported some more warnings
> after you applied these patches (and solved the conflicts I guess?)

I'll fix them, this is why we have wip/* branches :). 

Thanks

> 
> Thanks,
> Junxian
> 
> >  	attr->phys_state = attr->state == IB_PORT_ACTIVE ?
> >  		IB_PORT_PHYS_STATE_LINK_UP : IB_PORT_PHYS_STATE_DISABLED;
> >  	/*
> > 
> > 
> >>
> >> Junxian
> >