RDMA/core: Introduce RDMA subsystem ibdev_* print functions

Similarly to dev/netdev/etc printk helpers, add standard printk helpers
for the RDMA subsystem.

Example output:
efa 0000:00:06.0 efa_0: Hello World!
efa_0: Hello World! (no parent device set)
(NULL ib_device): Hello World! (ibdev is NULL)

Cc: Jason Baron <jbaron@akamai.com>
Suggested-by: Jason Gunthorpe <jgg@ziepe.ca>
Suggested-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Gal Pressman <galpress@amazon.com>
Reviewed-by: Leon Romanovsky <leonro@mellanox.com>
Reviewed-by: Shiraz Saleem <shiraz.saleem@intel.com>
Reviewed-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index 7bdf98c..8a16c2d 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -37,6 +37,8 @@
 #include <linux/device.h>
 #include <linux/netdevice.h>
 
+#include <rdma/ib_verbs.h>
+
 extern struct _ddebug __start___verbose[];
 extern struct _ddebug __stop___verbose[];
 
@@ -636,6 +638,41 @@ EXPORT_SYMBOL(__dynamic_netdev_dbg);
 
 #endif
 
+#if IS_ENABLED(CONFIG_INFINIBAND)
+
+void __dynamic_ibdev_dbg(struct _ddebug *descriptor,
+			 const struct ib_device *ibdev, const char *fmt, ...)
+{
+	struct va_format vaf;
+	va_list args;
+
+	va_start(args, fmt);
+
+	vaf.fmt = fmt;
+	vaf.va = &args;
+
+	if (ibdev && ibdev->dev.parent) {
+		char buf[PREFIX_SIZE];
+
+		dev_printk_emit(LOGLEVEL_DEBUG, ibdev->dev.parent,
+				"%s%s %s %s: %pV",
+				dynamic_emit_prefix(descriptor, buf),
+				dev_driver_string(ibdev->dev.parent),
+				dev_name(ibdev->dev.parent),
+				dev_name(&ibdev->dev),
+				&vaf);
+	} else if (ibdev) {
+		printk(KERN_DEBUG "%s: %pV", dev_name(&ibdev->dev), &vaf);
+	} else {
+		printk(KERN_DEBUG "(NULL ib_device): %pV", &vaf);
+	}
+
+	va_end(args);
+}
+EXPORT_SYMBOL(__dynamic_ibdev_dbg);
+
+#endif
+
 #define DDEBUG_STRING_SIZE 1024
 static __initdata char ddebug_setup_string[DDEBUG_STRING_SIZE];