[PATCH2/11] Add PRRN Event Handler

[Nathan Fontenot <nfont@linux.vnet.ibm.com>]

From: Jesse Larrew <jlarrew@linux.vnet.ibm.com>

A PRRN event is signaled via the RTAS event-scan mechanism, which
returns a Hot Plug Event message "fixed part" indicating "Platform
Resource Reassignment". In response to the Hot Plug Event message,
we must call ibm,update-nodes to determine which resources were
reassigned and then ibm,update-properties to obtain the new affinity
information about those resources.

The PRRN event-scan RTAS message contains only the "fixed part" with
the "Type" field set to the value 160 and no Extended Event Log. The
four-byte Extended Event Log Length field is repurposed (since no
Extended Event Log message is included) to pass the "scope" parameter
that causes the ibm,update-nodes to return the nodes affected by the
specific resource reassignment.

This patch adds a handler in rtasd for PRRN RTAS events. The function
pseries_devicetree_update() (from mobility.c) is used to make the
ibm,update-nodes/ibm,update-properties RTAS calls. Updating the NUMA maps
(handled by a subsequent patch) will require significant processing,
so pseries_devicetree_update() is called from an asynchronous workqueue
to allow rtasd to continue processing events.

Signed-off-by: Nathan Fontenot <nfont@linux.vnet.ibm.com>
---
 arch/powerpc/include/asm/rtas.h |    2 ++
 arch/powerpc/kernel/rtasd.c     |   35 ++++++++++++++++++++++++++++++++++-
 2 files changed, 36 insertions(+), 1 deletion(-)

Index: powerpc/arch/powerpc/include/asm/rtas.h
===================================================================
--- powerpc.orig/arch/powerpc/include/asm/rtas.h	2013-03-08 19:56:13.000000000 -0600
+++ powerpc/arch/powerpc/include/asm/rtas.h	2013-03-08 19:56:48.000000000 -0600
@@ -143,6 +143,8 @@
 #define RTAS_TYPE_PMGM_TIME_ALARM	0x6f
 #define RTAS_TYPE_PMGM_CONFIG_CHANGE	0x70
 #define RTAS_TYPE_PMGM_SERVICE_PROC	0x71
+/* Platform Resource Reassignment Notification */
+#define RTAS_TYPE_PRRN			0xA0
 
 /* RTAS check-exception vector offset */
 #define RTAS_VECTOR_EXTERNAL_INTERRUPT	0x500
Index: powerpc/arch/powerpc/kernel/rtasd.c
===================================================================
--- powerpc.orig/arch/powerpc/kernel/rtasd.c	2013-03-08 19:23:06.000000000 -0600
+++ powerpc/arch/powerpc/kernel/rtasd.c	2013-03-08 19:56:48.000000000 -0600
@@ -87,6 +87,8 @@
 			return "Resource Deallocation Event";
 		case RTAS_TYPE_DUMP:
 			return "Dump Notification Event";
+		case RTAS_TYPE_PRRN:
+			return "Platform Resource Reassignment Event";
 	}
 
 	return rtas_type[0];
@@ -265,7 +267,38 @@
 		spin_unlock_irqrestore(&rtasd_log_lock, s);
 		return;
 	}
+}
+
+static s32 update_scope;
+
+static void prrn_work_fn(struct work_struct *work)
+{
+	/*
+	 * For PRRN, we must pass the negative of the scope value in
+	 * the RTAS event.
+	 */
+	pseries_devicetree_update(-update_scope);
+}
+static DECLARE_WORK(prrn_work, prrn_work_fn);
+
+void prrn_schedule_update(u32 scope)
+{
+	flush_work(&prrn_work);
+	update_scope = scope;
+	schedule_work(&prrn_work);
+}
+
+static void pseries_handle_event(const struct rtas_error_log *log)
+{
+	pSeries_log_error((char *)log, ERR_TYPE_RTAS_LOG, 0);
+
+	if (log->type == RTAS_TYPE_PRRN)
+		/* For PRRN Events the extended log length is used to denote
+		 * the scope for calling rtas update-nodes.
+		 */
+		prrn_schedule_update(log->extended_log_length);
 
+	return;
 }
 
 static int rtas_log_open(struct inode * inode, struct file * file)
@@ -389,7 +422,7 @@
 		}
 
 		if (error == 0)
-			pSeries_log_error(logdata, ERR_TYPE_RTAS_LOG, 0);
+			pseries_handle_event((struct rtas_error_log *)logdata);
 
 	} while(error == 0);
 }