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Diffstat (limited to 'arch/arm64/kernel/cpu_ops.c')
-rw-r--r--arch/arm64/kernel/cpu_ops.c87
1 files changed, 87 insertions, 0 deletions
diff --git a/arch/arm64/kernel/cpu_ops.c b/arch/arm64/kernel/cpu_ops.c
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index 000000000000..d62d12fb36c8
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+++ b/arch/arm64/kernel/cpu_ops.c
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+/*
+ * CPU kernel entry/exit control
+ *
+ * Copyright (C) 2013 ARM Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#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;
+extern const struct cpu_operations cpu_psci_ops;
+
+const struct cpu_operations *cpu_ops[NR_CPUS];
+
+static const struct cpu_operations *supported_cpu_ops[] __initconst = {
+#ifdef CONFIG_SMP
+ &smp_spin_table_ops,
+ &cpu_psci_ops,
+#endif
+ NULL,
+};
+
+static const struct cpu_operations * __init cpu_get_ops(const char *name)
+{
+ const struct cpu_operations **ops = supported_cpu_ops;
+
+ while (*ops) {
+ if (!strcmp(name, (*ops)->name))
+ return *ops;
+
+ ops++;
+ }
+
+ 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_warn("%s: unsupported 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 = of_get_cpu_node(0, NULL);
+ if (!dn) {
+ pr_err("Failed to find device node for boot cpu\n");
+ return;
+ }
+ cpu_read_ops(dn, 0);
+}