[PATCH rdma-next v1 1/3] IB/cache: Add log messages for IB device state changes

[Leon Romanovsky <leon@kernel.org>]

From: Maher Sanalla <msanalla@nvidia.com>

Enhance visibility into IB device state transitions by adding log messages
to the kernel log (dmesg). Whenever an IB device changes state, a relevant
print will be printed, such as:

"mlx5_core 0000:08:00.0 mlx5_0: Port: 1 Link DOWN"
"mlx5_core 0000:08:00.0 rdmap8s0f0: Port: 2 Link ACTIVE"

Signed-off-by: Maher Sanalla <msanalla@nvidia.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
---
 drivers/infiniband/core/cache.c |  6 ++++++
 include/rdma/ib_verbs.h         | 17 +++++++++++++++++
 2 files changed, 23 insertions(+)

diff --git a/drivers/infiniband/core/cache.c b/drivers/infiniband/core/cache.c
index f8413f8a9f26..9979a351577f 100644
--- a/drivers/infiniband/core/cache.c
+++ b/drivers/infiniband/core/cache.c
@@ -1501,6 +1501,12 @@ ib_cache_update(struct ib_device *device, u32 port, bool update_gids,
 		device->port_data[port].cache.pkey = pkey_cache;
 	}
 	device->port_data[port].cache.lmc = tprops->lmc;
+
+	if (device->port_data[port].cache.port_state != IB_PORT_NOP &&
+	    device->port_data[port].cache.port_state != tprops->state)
+		ibdev_info(device, "Port: %d Link %s\n", port,
+			   ib_port_state_to_str(tprops->state));
+
 	device->port_data[port].cache.port_state = tprops->state;
 
 	device->port_data[port].cache.subnet_prefix = tprops->subnet_prefix;
diff --git a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h
index 0ad104dae253..b59bf30de430 100644
--- a/include/rdma/ib_verbs.h
+++ b/include/rdma/ib_verbs.h
@@ -519,6 +519,23 @@ enum ib_port_state {
 	IB_PORT_ACTIVE_DEFER	= 5
 };
 
+static inline const char *__attribute_const__
+ib_port_state_to_str(enum ib_port_state state)
+{
+	const char * const states[] = {
+		[IB_PORT_NOP] = "NOP",
+		[IB_PORT_DOWN] = "DOWN",
+		[IB_PORT_INIT] = "INIT",
+		[IB_PORT_ARMED] = "ARMED",
+		[IB_PORT_ACTIVE] = "ACTIVE",
+		[IB_PORT_ACTIVE_DEFER] = "ACTIVE_DEFER",
+	};
+
+	if (state < ARRAY_SIZE(states))
+		return states[state];
+	return "UNKNOWN";
+}
+
 enum ib_port_phys_state {
 	IB_PORT_PHYS_STATE_SLEEP = 1,
 	IB_PORT_PHYS_STATE_POLLING = 2,
-- 
2.48.1