Re: [RFC PATCH 06/11] IB/Verbs: Use management helper has_sa() and cap_sa(), for sa-check

[ira.weiny]

On Fri, Mar 27, 2015 at 04:46:11PM +0100, Michael Wang wrote:
> 
> Introduce helper has_sa() and cap_sa() to help us check if an IB device
> or it's port support Subnet Administrator.

I think these 2 should be combined.  The question is if a port requires the use
of the SA depending on the network it is connected to.

Aren't some dual port Mellanox cards capable of doing IB on 1 port and Eth on
the other?  Do they show up as 2 devices?

Regardless I think we should define the SA access on a per port basis.

> 
> Cc: Jason Gunthorpe <jgunthorpe@xxxxxxxxxxxxxxxxxxxx>
> Cc: Doug Ledford <dledford@xxxxxxxxxx>
> Cc: Ira Weiny <ira.weiny@xxxxxxxxx>
> Cc: Sean Hefty <sean.hefty@xxxxxxxxx>
> Signed-off-by: Michael Wang <yun.wang@xxxxxxxxxxxxxxxx>
> ---
>  drivers/infiniband/core/sa_query.c | 12 ++++++------
>  include/rdma/ib_verbs.h            | 28 ++++++++++++++++++++++++++++
>  2 files changed, 34 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/infiniband/core/sa_query.c b/drivers/infiniband/core/sa_query.c
> index d95d25f..89c27da 100644
> --- a/drivers/infiniband/core/sa_query.c
> +++ b/drivers/infiniband/core/sa_query.c
> @@ -450,7 +450,7 @@ static void ib_sa_event(struct ib_event_handler *handler, struct ib_event *event
>          struct ib_sa_port *port =
>              &sa_dev->port[event->element.port_num - sa_dev->start_port];
>  
> -        if (!rdma_port_ll_is_ib(handler->device, port->port_num))
> +        if (!cap_sa(handler->device, port->port_num))
>              return;
>  
>          spin_lock_irqsave(&port->ah_lock, flags);
> @@ -1154,7 +1154,7 @@ static void ib_sa_add_one(struct ib_device *device)
>      struct ib_sa_device *sa_dev;
>      int s, e, i;
>  
> -    if (!rdma_transport_is_ib(device))
> +    if (!has_sa(device))

The logic here should be:

if (no ports of this device need sa access)
	return;

So why not eliminate this check and allow the cap_sa(s) to handle the support?

-- Ira

>          return;
>  
>      if (device->node_type == RDMA_NODE_IB_SWITCH)
> @@ -1175,7 +1175,7 @@ static void ib_sa_add_one(struct ib_device *device)
>  
>      for (i = 0; i <= e - s; ++i) {
>          spin_lock_init(&sa_dev->port[i].ah_lock);
> -        if (!rdma_port_ll_is_ib(device, i + 1))
> +        if (!cap_sa(device, i + 1))
>              continue;
>  
>          sa_dev->port[i].sm_ah    = NULL;
> @@ -1205,14 +1205,14 @@ static void ib_sa_add_one(struct ib_device *device)
>          goto err;
>  
>      for (i = 0; i <= e - s; ++i)
> -        if (rdma_port_ll_is_ib(device, i + 1))
> +        if (cap_sa(device, i + 1))
>              update_sm_ah(&sa_dev->port[i].update_task);
>  
>      return;
>  
>  err:
>      while (--i >= 0)
> -        if (rdma_port_ll_is_ib(device, i + 1))
> +        if (cap_sa(device, i + 1))
>              ib_unregister_mad_agent(sa_dev->port[i].agent);
>  
>      kfree(sa_dev);
> @@ -1233,7 +1233,7 @@ static void ib_sa_remove_one(struct ib_device *device)
>      flush_workqueue(ib_wq);
>  
>      for (i = 0; i <= sa_dev->end_port - sa_dev->start_port; ++i) {
> -        if (rdma_port_ll_is_ib(device, i + 1)) {
> +        if (cap_sa(device, i + 1)) {
>              ib_unregister_mad_agent(sa_dev->port[i].agent);
>              if (sa_dev->port[i].sm_ah)
>                  kref_put(&sa_dev->port[i].sm_ah->ref, free_sm_ah);
> diff --git a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h
> index c0a63f8..fa8ffa3 100644
> --- a/include/rdma/ib_verbs.h
> +++ b/include/rdma/ib_verbs.h
> @@ -1810,6 +1810,19 @@ static inline int has_cm(struct ib_device *device)
>  }
>  
>  /**
> + * has_sa - Check if a device support Subnet Administrator.
> + *
> + * @device: Device to be checked
> + *
> + * Return 0 when a device has none port to support
> + * Subnet Administrator.
> + */
> +static inline int has_sa(struct ib_device *device)
> +{
> +    return rdma_transport_is_ib(device);
> +}
> +
> +/**
>   * cap_smi - Check if the port of device has the capability
>   * Subnet Management Interface.
>   *
> @@ -1824,6 +1837,21 @@ static inline int cap_smi(struct ib_device *device, u8 port_num)
>      return rdma_port_ll_is_ib(device, port_num);
>  }
>  
> +/**
> + * cap_sa - Check if the port of device has the capability
> + * Subnet Administrator.
> + *
> + * @device: Device to be checked
> + * @port_num: Port number of the device
> + *
> + * Return 0 when port of the device don't support
> + * Subnet Administrator.
> + */
> +static inline int cap_sa(struct ib_device *device, u8 port_num)
> +{
> +    return rdma_port_ll_is_ib(device, port_num);
> +}
> +
>  int ib_query_gid(struct ib_device *device,
>           u8 port_num, int index, union ib_gid *gid);
>  
> -- 
> 2.1.0
> 
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