powerpc/powernv: Add new opal message type

We have OPAL_MSG_PRD message type to pass prd related messages from
OPAL to `opal-prd`. It can handle messages upto 64 bytes. We have a
requirement to send bigger than 64 bytes of data from OPAL to
`opal-prd`. Lets add new message type (OPAL_MSG_PRD2) to pass bigger
data.

Signed-off-by: Vasant Hegde <hegdevasant@linux.vnet.ibm.com>
[mpe: Make the error string clear that it's the PRD2 event that failed]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190826065701.8853-2-hegdevasant@linux.vnet.ibm.com

arch/powerpc/include/asm/opal-api.h

@@ -453,6 +453,7 @@ enum opal_msg_type {
 	OPAL_MSG_DPO		= 5,
 	OPAL_MSG_PRD		= 6,
 	OPAL_MSG_OCC		= 7,
+	OPAL_MSG_PRD2		= 8,
 	OPAL_MSG_TYPE_MAX,
 };
 

arch/powerpc/platforms/powernv/opal-prd.c

@@ -342,7 +342,7 @@ static int opal_prd_msg_notifier(struct notifier_block *nb,
 	int msg_size, item_size;
 	unsigned long flags;
 
-	if (msg_type != OPAL_MSG_PRD)
+	if (msg_type != OPAL_MSG_PRD && msg_type != OPAL_MSG_PRD2)
 		return 0;
 
 	/* Calculate total size of the message and item we need to store. The
@@ -393,6 +393,12 @@ static int opal_prd_probe(struct platform_device *pdev)
 		return rc;
 	}
 
+	rc = opal_message_notifier_register(OPAL_MSG_PRD2, &opal_prd_event_nb);
+	if (rc) {
+		pr_err("Couldn't register PRD2 event notifier\n");
+		return rc;
+	}
+
 	rc = misc_register(&opal_prd_dev);
 	if (rc) {
 		pr_err("failed to register miscdev\n");