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;