Subject: Re: [RFC PATCH 07/11] IB/Verbs: Use management helper has_mcast() and, cap_mcast() for mcast-check

From: Michael Wang <[email-masked]>
Date: Mon, 30 Mar 2015 18:20:48 +0200

On 03/30/2015 06:11 PM, Doug Ledford wrote:
> On Fri, 2015-03-27 at 16:46 +0100, Michael Wang wrote:
>> Introduce helper has_mcast() and cap_mcast() to help us check if an
>> IB device or it's port support Multicast.
> This probably needs reworded or rethought.  In truth, *all* rdma devices
> are multicast capable.  *BUT*, IB/OPA devices require multicast
> registration done the IB way (including for sendonly multicast sends),
> while Ethernet devices do multicast the Ethernet way.  These tests are
> really just for IB specific multicast registration and deregistration.
> Call it has_mcast() and cap_mcast() is incorrect.

Thanks for the explanation :-)

Jason also mentioned we should use cap_ib_XX() instead, I'll use
that name then we can distinguish the management between
Eth and IB/OPA.

Regards,
Michael Wang

>
>> Cc: Jason Gunthorpe <[email-masked]>
>> Cc: Doug Ledford <[email-masked]>
>> Cc: Ira Weiny <[email-masked]>
>> Cc: Sean Hefty <[email-masked]>
>> Signed-off-by: Michael Wang <[email-masked]>
>> ---
>>  drivers/infiniband/core/cma.c       |  2 +-
>>  drivers/infiniband/core/multicast.c |  8 ++++----
>>  include/rdma/ib_verbs.h             | 28 ++++++++++++++++++++++++++++
>>  3 files changed, 33 insertions(+), 5 deletions(-)
>>
>> diff --git a/drivers/infiniband/core/cma.c b/drivers/infiniband/core/cma.c
>> index 276fb76..cbbc85b 100644
>> --- a/drivers/infiniband/core/cma.c
>> +++ b/drivers/infiniband/core/cma.c
>> @@ -3398,7 +3398,7 @@ void rdma_leave_multicast(struct rdma_cm_id *id, struct sockaddr *addr)
>>                  ib_detach_mcast(id->qp,
>>                          &mc->multicast.ib->rec.mgid,
>>                          be16_to_cpu(mc->multicast.ib->rec.mlid));
>> -            if (rdma_transport_is_ib(id_priv->cma_dev->device)) {
>> +            if (has_mcast(id_priv->cma_dev->device)) {
>>                  switch (rdma_port_get_link_layer(id->device, id->port_num)) {
>>                  case IB_LINK_LAYER_INFINIBAND:
>>                      ib_sa_free_multicast(mc->multicast.ib);
>> diff --git a/drivers/infiniband/core/multicast.c b/drivers/infiniband/core/multicast.c
>> index 17573ff..ffeaf27 100644
>> --- a/drivers/infiniband/core/multicast.c
>> +++ b/drivers/infiniband/core/multicast.c
>> @@ -780,7 +780,7 @@ static void mcast_event_handler(struct ib_event_handler *handler,
>>      int index;
>>  
>>      dev = container_of(handler, struct mcast_device, event_handler);
>> -    if (!rdma_port_ll_is_ib(dev->device, event->element.port_num))
>> +    if (!cap_mcast(dev->device, event->element.port_num))
>>          return;
>>  
>>      index = event->element.port_num - dev->start_port;
>> @@ -807,7 +807,7 @@ static void mcast_add_one(struct ib_device *device)
>>      int i;
>>      int count = 0;
>>  
>> -    if (!rdma_transport_is_ib(device))
>> +    if (!has_mcast(device))
>>          return;
>>  
>>      dev = kmalloc(sizeof *dev + device->phys_port_cnt * sizeof *port,
>> @@ -823,7 +823,7 @@ static void mcast_add_one(struct ib_device *device)
>>      }
>>  
>>      for (i = 0; i <= dev->end_port - dev->start_port; i++) {
>> -        if (!rdma_port_ll_is_ib(device, dev->start_port + i))
>> +        if (!cap_mcast(device, dev->start_port + i))
>>              continue;
>>          port = &dev->port[i];
>>          port->dev = dev;
>> @@ -861,7 +861,7 @@ static void mcast_remove_one(struct ib_device *device)
>>      flush_workqueue(mcast_wq);
>>  
>>      for (i = 0; i <= dev->end_port - dev->start_port; i++) {
>> -        if (rdma_port_ll_is_ib(device, dev->start_port + i)) {
>> +        if (cap_mcast(device, dev->start_port + i)) {
>>              port = &dev->port[i];
>>              deref_port(port);
>>              wait_for_completion(&port->comp);
>> diff --git a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h
>> index fa8ffa3..e796104 100644
>> --- a/include/rdma/ib_verbs.h
>> +++ b/include/rdma/ib_verbs.h
>> @@ -1823,6 +1823,19 @@ static inline int has_sa(struct ib_device *device)
>>  }
>>  
>>  /**
>> + * has_mcast - Check if a device support Multicast.
>> + *
>> + * @device: Device to be checked
>> + *
>> + * Return 0 when a device has none port to support
>> + * Multicast.
>> + */
>> +static inline int has_mcast(struct ib_device *device)
>> +{
>> +    return rdma_transport_is_ib(device);
>> +}
>> +
>> +/**
>>   * cap_smi - Check if the port of device has the capability
>>   * Subnet Management Interface.
>>   *
>> @@ -1852,6 +1865,21 @@ static inline int cap_sa(struct ib_device *device, u8 port_num)
>>      return rdma_port_ll_is_ib(device, port_num);
>>  }
>>  
>> +/**
>> + * cap_mcast - Check if the port of device has the capability
>> + * Multicast.
>> + *
>> + * @device: Device to be checked
>> + * @port_num: Port number of the device
>> + *
>> + * Return 0 when port of the device don't support
>> + * Multicast.
>> + */
>> +static inline int cap_mcast(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);
>>  
>