ipoib: Make ipoib_warn ratelimited

In certain cases it's possible to be flooded by warning messages. To
cope with such situations make the ipoib_warn macro be ratelimited.
To prevent accidental limiting of legitimate, bursty messages make
the limit fairly liberal by allowing up to 100 messages in 10 seconds.

Signed-off-by: Nikolay Borisov <[e-mail]>
Signed-off-by: Doug Ledford <[e-mail]>

drivers/infiniband/ulp/ipoib/ipoib.h

···
 #define ipoib_printk(level, priv, format, arg...)	\
 	printk(level "%s: " format, ((struct ipoib_dev_priv *) priv)->dev->name , ## arg)
 #define ipoib_warn(priv, format, arg...)		\
-	ipoib_printk(KERN_WARNING, priv, format , ## arg)
+do {							\
+	static DEFINE_RATELIMIT_STATE(_rs,		\
+		10 * HZ /*10 seconds */,		\
+		100);		\
+	if (__ratelimit(&_rs))				\
+		ipoib_printk(KERN_WARNING, priv, format , ## arg);\
+} while (0)
 
 extern int ipoib_sendq_size;
 extern int ipoib_recvq_size;