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-rw-r--r--arch/powerpc/kernel/prom.c43
1 files changed, 43 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c
index 629023240ec..483455c5bb0 100644
--- a/arch/powerpc/kernel/prom.c
+++ b/arch/powerpc/kernel/prom.c
@@ -2105,3 +2105,46 @@ int prom_update_property(struct device_node *np,
return 0;
}
+
+/* Find the device node for a given logical cpu number, also returns the cpu
+ * local thread number (index in ibm,interrupt-server#s) if relevant and
+ * asked for (non NULL)
+ */
+struct device_node *of_get_cpu_node(int cpu, unsigned int *thread)
+{
+ int hardid;
+ struct device_node *np;
+
+ hardid = get_hard_smp_processor_id(cpu);
+
+ for_each_node_by_type(np, "cpu") {
+ u32 *intserv;
+ unsigned int plen, t;
+
+ /* Check for ibm,ppc-interrupt-server#s. If it doesn't exist
+ * fallback to "reg" property and assume no threads
+ */
+ intserv = (u32 *)get_property(np, "ibm,ppc-interrupt-server#s",
+ &plen);
+ if (intserv == NULL) {
+ u32 *reg = (u32 *)get_property(np, "reg", NULL);
+ if (reg == NULL)
+ continue;
+ if (*reg == hardid) {
+ if (thread)
+ *thread = 0;
+ return np;
+ }
+ } else {
+ plen /= sizeof(u32);
+ for (t = 0; t < plen; t++) {
+ if (hardid == intserv[t]) {
+ if (thread)
+ *thread = t;
+ return np;
+ }
+ }
+ }
+ }
+ return NULL;
+}