[IA64] Enable percpu vector domain for IA64_GENERIC

Add per-CPU vector domain support for IA64_GENERIC. It is enabled by
adding the "vector=percpu" boot option.
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

Documentation/kernel-parameters.txt

@@ -1859,6 +1859,9 @@ and is between 256 and 4096 characters. It is defined in the file
 			vdso=1: enable VDSO (default)
 			vdso=0: disable VDSO mapping
 
+	vector=		[IA-64,SMP]
+			vector=percpu: enable percpu vector domain
+
 	video=		[FB] Frame buffer configuration
 			See Documentation/fb/modedb.txt.
 

arch/ia64/kernel/irq_ia64.c

@@ -267,10 +267,36 @@ void __setup_vector_irq(int cpu)
 	}
 }
 
+#if defined(CONFIG_IA64_GENERIC)
+static enum vector_domain_type {
+	VECTOR_DOMAIN_NONE,
+	VECTOR_DOMAIN_PERCPU
+} vector_domain_type = VECTOR_DOMAIN_NONE;
+
+static cpumask_t vector_allocation_domain(int cpu)
+{
+	if (vector_domain_type == VECTOR_DOMAIN_PERCPU)
+		return cpumask_of_cpu(cpu);
+	return CPU_MASK_ALL;
+}
+
+static int __init parse_vector_domain(char *arg)
+{
+	if (!arg)
+		return -EINVAL;
+	if (!strcmp(arg, "percpu")) {
+		vector_domain_type = VECTOR_DOMAIN_PERCPU;
+		no_int_routing = 1;
+	}
+	return 1;
+}
+early_param("vector", parse_vector_domain);
+#else
 static cpumask_t vector_allocation_domain(int cpu)
 {
 	return CPU_MASK_ALL;
 }
+#endif
 
 
 void destroy_and_reserve_irq(unsigned int irq)