1 files changed, 40 insertions, 0 deletions

diff --git a/arch/arm/kernel/devtree.c b/arch/arm/kernel/devtree.c
index f751714d52c1..c7419a585ddc 100644
--- a/arch/arm/kernel/devtree.c
+++ b/arch/arm/kernel/devtree.c
@@ -18,6 +18,7 @@
 #include <linux/of_fdt.h>
 #include <linux/of_irq.h>
 #include <linux/of_platform.h>
+#include <linux/smp.h>
 
 #include <asm/cputype.h>
 #include <asm/setup.h>
@@ -63,6 +64,34 @@ void __init arm_dt_memblock_reserve(void)
         }
 }
 
+#ifdef CONFIG_SMP
+extern struct of_cpu_method __cpu_method_of_table_begin[];
+extern struct of_cpu_method __cpu_method_of_table_end[];
+
+static int __init set_smp_ops_by_method(struct device_node *node)
+{
+        const char *method;
+        struct of_cpu_method *m = __cpu_method_of_table_begin;
+
+        if (of_property_read_string(node, "enable-method", &method))
+                return 0;
+
+        for (; m < __cpu_method_of_table_end; m++)
+                if (!strcmp(m->method, method)) {
+                        smp_set_ops(m->ops);
+                        return 1;
+                }
+
+        return 0;
+}
+#else
+static inline int set_smp_ops_by_method(struct device_node *node)
+{
+        return 1;
+}
+#endif
+
+
 /*
  * arm_dt_init_cpu_maps - Function retrieves cpu nodes from the device tree
  * and builds the cpu logical map array containing MPIDR values related to
@@ -79,6 +108,7 @@ void __init arm_dt_init_cpu_maps(void)
          * read as 0.
          */
         struct device_node *cpu, *cpus;
+        int found_method = 0;
         u32 i, j, cpuidx = 1;
         u32 mpidr = is_smp() ? read_cpuid_mpidr() & MPIDR_HWID_BITMASK : 0;
 
@@ -150,8 +180,18 @@ void __init arm_dt_init_cpu_maps(void)
                 }
 
                 tmp_map[i] = hwid;
+
+                if (!found_method)
+                        found_method = set_smp_ops_by_method(cpu);
         }
 
+        /*
+         * Fallback to an enable-method in the cpus node if nothing found in
+         * a cpu node.
+         */
+        if (!found_method)
+                set_smp_ops_by_method(cpus);
+
         if (!bootcpu_valid) {
                 pr_warn("DT missing boot CPU MPIDR[23:0], fall back to default cpu_logical_map\n");
                 return;