/* * 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);}