powerpc/eeh: Refactor the output message

We needn't the the whole backtrace other than one-line message in
the error reporting interrupt handler. For errors triggered by
access PCI config space or MMIO, we replace "WARN(1, ...)" with
pr_err() and dump_stack(). The patch also adds more output messages
to indicate what EEH core is doing. Besides, some printk() are
replaced with pr_warning().

Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

arch/powerpc/kernel/eeh.c

@@ -329,7 +329,9 @@ static int eeh_phb_check_failure(struct eeh_pe *pe)
 	eeh_serialize_unlock(flags);
 	eeh_send_failure_event(phb_pe);
 
-	WARN(1, "EEH: PHB failure detected\n");
+	pr_err("EEH: PHB#%x failure detected\n",
+		phb_pe->phb->global_number);
+	dump_stack();
 
 	return 1;
 out:
@@ -458,7 +460,10 @@ int eeh_dev_check_failure(struct eeh_dev *edev)
 	 * a stack trace will help the device-driver authors figure
 	 * out what happened.  So print that out.
 	 */
-	WARN(1, "EEH: failure detected\n");
+	pr_err("EEH: Frozen PE#%x detected on PHB#%x\n",
+		pe->addr, pe->phb->global_number);
+	dump_stack();
+
 	return 1;
 
 dn_unlock: