IB: Add rdma_cap_ib_switch helper and use where appropriate

Persuant to Liran's comments on node_type on linux-rdma
mailing list:

In an effort to reform the RDMA core and ULPs to minimize use of
node_type in struct ib_device, an additional bit is added to
struct ib_device for is_switch (IB switch). This is needed
to be initialized by any IB switch device driver. This is a
NEW requirement on such device drivers which are all
"out of tree".

In addition, an ib_switch helper was added to ib_verbs.h
based on the is_switch device bit rather than node_type
(although those should be consistent).

The RDMA core (MAD, SMI, agent, sa_query, multicast, sysfs)
as well as (IPoIB and SRP) ULPs are updated where
appropriate to use this new helper. In some cases,
the helper is now used under the covers of using
rdma_[start end]_port rather than the open coding
previously used.

Reviewed-by: Sean Hefty <sean.hefty@intel.com>
Reviewed-By: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Tested-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Hal Rosenstock <hal@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

1 files changed, 17 insertions, 3 deletions

diff --git a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h
index 986fddb..b0f898e 100644
--- a/include/rdma/ib_verbs.h
+++ b/include/rdma/ib_verbs.h
@@ -1745,6 +1745,7 @@ struct ib_device {
 	char			     node_desc[64];
 	__be64			     node_guid;
 	u32			     local_dma_lkey;
+	u16                          is_switch:1;
 	u8                           node_type;
 	u8                           phys_port_cnt;
 
@@ -1824,6 +1825,20 @@ enum rdma_link_layer rdma_port_get_link_layer(struct ib_device *device,
 					       u8 port_num);
 
 /**
+ * rdma_cap_ib_switch - Check if the device is IB switch
+ * @device: Device to check
+ *
+ * Device driver is responsible for setting is_switch bit on
+ * in ib_device structure at init time.
+ *
+ * Return: true if the device is IB switch.
+ */
+static inline bool rdma_cap_ib_switch(const struct ib_device *device)
+{
+	return device->is_switch;
+}
+
+/**
  * rdma_start_port - Return the first valid port number for the device
  * specified
  *
@@ -1833,7 +1848,7 @@ enum rdma_link_layer rdma_port_get_link_layer(struct ib_device *device,
  */
 static inline u8 rdma_start_port(const struct ib_device *device)
 {
-	return (device->node_type == RDMA_NODE_IB_SWITCH) ? 0 : 1;
+	return rdma_cap_ib_switch(device) ? 0 : 1;
 }
 
 /**
@@ -1846,8 +1861,7 @@ static inline u8 rdma_start_port(const struct ib_device *device)
  */
 static inline u8 rdma_end_port(const struct ib_device *device)
 {
-	return (device->node_type == RDMA_NODE_IB_SWITCH) ?
-		0 : device->phys_port_cnt;
+	return rdma_cap_ib_switch(device) ? 0 : device->phys_port_cnt;
 }
 
 static inline bool rdma_protocol_ib(const struct ib_device *device, u8 port_num)