arm64: read enable-method for CPU0

[firefly-linux-kernel-4.4.55.git] / arch / arm64 / kernel / cpu_ops.c

diff --git a/arch/arm64/kernel/cpu_ops.c b/arch/arm64/kernel/cpu_ops.c
index e2652aadd9ea23055bf6dd60e64d73bd5d159013..aa0c9e78dbe139883f726be1221ed2ec74f3e017 100644 (file)
--- a/arch/arm64/kernel/cpu_ops.c
+++ b/arch/arm64/kernel/cpu_ops.c
@@ -17,6 +17,9 @@
  */
 
 #include <asm/cpu_ops.h>
+#include <asm/smp_plat.h>
+#include <linux/errno.h>
+#include <linux/of.h>
 #include <linux/string.h>
 
 extern const struct cpu_operations smp_spin_table_ops;
@@ -32,7 +35,7 @@ static const struct cpu_operations *supported_cpu_ops[] __initconst = {
        NULL,
 };
 
-const struct cpu_operations * __init cpu_get_ops(const char *name)
+static const struct cpu_operations * __init cpu_get_ops(const char *name)
 {
        const struct cpu_operations **ops = supported_cpu_ops;
 
@@ -45,3 +48,52 @@ const struct cpu_operations * __init cpu_get_ops(const char *name)
 
        return NULL;
 }
+
+/*
+ * Read a cpu's enable method from the device tree and record it in cpu_ops.
+ */
+int __init cpu_read_ops(struct device_node *dn, int cpu)
+{
+       const char *enable_method = of_get_property(dn, "enable-method", NULL);
+       if (!enable_method) {
+               /*
+                * The boot CPU may not have an enable method (e.g. when
+                * spin-table is used for secondaries). Don't warn spuriously.
+                */
+               if (cpu != 0)
+                       pr_err("%s: missing enable-method property\n",
+                               dn->full_name);
+               return -ENOENT;
+       }
+
+       cpu_ops[cpu] = cpu_get_ops(enable_method);
+       if (!cpu_ops[cpu]) {
+               pr_err("%s: invalid enable-method property: %s\n",
+                      dn->full_name, enable_method);
+               return -EOPNOTSUPP;
+       }
+
+       return 0;
+}
+
+void __init cpu_read_bootcpu_ops(void)
+{
+       struct device_node *dn = NULL;
+       u64 mpidr = cpu_logical_map(0);
+
+       while ((dn = of_find_node_by_type(dn, "cpu"))) {
+               u64 hwid;
+               const __be32 *prop;
+
+               prop = of_get_property(dn, "reg", NULL);
+               if (!prop)
+                       continue;
+
+               hwid = of_read_number(prop, of_n_addr_cells(dn));
+               if (hwid == mpidr) {
+                       cpu_read_ops(dn, 0);
+                       of_node_put(dn);
+                       return;
+               }
+       }
+}