1 files changed, 53 insertions, 0 deletions
diff --git a/arch/sparc/kernel/prom_64.c b/arch/sparc/kernel/prom_64.c
index d397d7fc5c28..6b39125eb927 100644
--- a/arch/sparc/kernel/prom_64.c
+++ b/arch/sparc/kernel/prom_64.c
@@ -373,6 +373,59 @@ static const char *get_mid_prop(void)
 	return (tlb_type == spitfire ? "upa-portid" : "portid");
 }
 
+bool arch_find_n_match_cpu_physical_id(struct device_node *cpun,
+				       int cpu, unsigned int *thread)
+{
+	const char *mid_prop = get_mid_prop();
+	int this_cpu_id;
+
+	/* On hypervisor based platforms we interrogate the 'reg'
+	 * property.  On everything else we look for a 'upa-portis',
+	 * 'portid', or 'cpuid' property.
+	 */
+
+	if (tlb_type == hypervisor) {
+		struct property *prop = of_find_property(cpun, "reg", NULL);
+		u32 *regs;
+
+		if (!prop) {
+			pr_warn("CPU node missing reg property\n");
+			return false;
+		}
+		regs = prop->value;
+		this_cpu_id = regs[0] & 0x0fffffff;
+	} else {
+		this_cpu_id = of_getintprop_default(cpun, mid_prop, -1);
+
+		if (this_cpu_id < 0) {
+			mid_prop = "cpuid";
+			this_cpu_id = of_getintprop_default(cpun, mid_prop, -1);
+		}
+		if (this_cpu_id < 0) {
+			pr_warn("CPU node missing cpu ID property\n");
+			return false;
+		}
+	}
+	if (this_cpu_id == cpu) {
+		if (thread) {
+			int proc_id = cpu_data(cpu).proc_id;
+
+			/* On sparc64, the cpu thread information is obtained
+			 * either from OBP or the machine description.  We've
+			 * actually probed this information already long before
+			 * this interface gets called so instead of interrogating
+			 * both the OF node and the MDESC again, just use what
+			 * we discovered already.
+			 */
+			if (proc_id < 0)
+				proc_id = 0;
+			*thread = proc_id;
+		}
+		return true;
+	}
+	return false;
+}
+
 static void *of_iterate_over_cpus(void *(*func)(struct device_node *, int, int), int arg)
 {
 	struct device_node *dp;