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Date: Tue, 9 Oct 2007 19:08:15 -0500
From: Olof Johansson <olof@lixom.net>
To: Linus Torvalds <torvalds@linux-foundation.org>
Subject: [PATCH] powerpc: don't enable cpu hotplug on mpic-based pseries
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Don't allow cpu hotplug on systems lacking XICS interrupt controller,
since current platform code is hardcoded for it.


Signed-off-by: Olof Johansson <olof@lixom.net>


diff --git a/arch/powerpc/platforms/pseries/hotplug-cpu.c b/arch/powerpc/platforms/pseries/hotplug-cpu.c
index 9711eb0..e29b890 100644
--- a/arch/powerpc/platforms/pseries/hotplug-cpu.c
+++ b/arch/powerpc/platforms/pseries/hotplug-cpu.c
@@ -252,6 +252,19 @@ static struct notifier_block pseries_smp_nb = {
 
 static int __init pseries_cpu_hotplug_init(void)
 {
+	struct device_node *np;
+	const char *typep;
+
+	for (np = NULL; (np = of_find_node_by_name(np,
+						   "interrupt-controller"));) {
+		typep = of_get_property(np, "compatible", NULL);
+		if (strstr(typep, "open-pic")) {
+			printk(KERN_INFO "CPU Hotplug not supported on "
+				"systems using MPIC\n");
+			return 0;
+		}
+	}
+
 	rtas_stop_self_args.token = rtas_token("stop-self");
 	qcss_tok = rtas_token("query-cpu-stopped-state");