1/*
2 * CPU kernel entry/exit control
3 *
4 * Copyright (C) 2013 ARM Ltd.
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
17 */
18
19#include <asm/cpu_ops.h>
20#include <asm/smp_plat.h>
21#include <linux/errno.h>
22#include <linux/of.h>
23#include <linux/string.h>
24
25extern const struct cpu_operations smp_spin_table_ops;
26extern const struct cpu_operations cpu_psci_ops;
27
28const struct cpu_operations *cpu_ops[NR_CPUS];
29
30static const struct cpu_operations *supported_cpu_ops[] __initconst = {
31#ifdef CONFIG_SMP
32	&smp_spin_table_ops,
33#endif
34	&cpu_psci_ops,
35	NULL,
36};
37
38const struct cpu_operations * __init cpu_get_ops(const char *name)
39{
40	const struct cpu_operations **ops = supported_cpu_ops;
41
42	while (*ops) {
43		if (!strcmp(name, (*ops)->name))
44			return *ops;
45
46		ops++;
47	}
48
49	return NULL;
50}
51
52/*
53 * Read a cpu's enable method from the device tree and record it in cpu_ops.
54 */
55int __init cpu_read_ops(struct device_node *dn, int cpu)
56{
57	const char *enable_method = of_get_property(dn, "enable-method", NULL);
58	if (!enable_method) {
59		/*
60		 * The boot CPU may not have an enable method (e.g. when
61		 * spin-table is used for secondaries). Don't warn spuriously.
62		 */
63		if (cpu != 0)
64			pr_err("%s: missing enable-method property\n",
65				dn->full_name);
66		return -ENOENT;
67	}
68
69	cpu_ops[cpu] = cpu_get_ops(enable_method);
70	if (!cpu_ops[cpu]) {
71		pr_warn("%s: unsupported enable-method property: %s\n",
72			dn->full_name, enable_method);
73		return -EOPNOTSUPP;
74	}
75
76	return 0;
77}
78
79void __init cpu_read_bootcpu_ops(void)
80{
81	struct device_node *dn = of_get_cpu_node(0, NULL);
82	if (!dn) {
83		pr_err("Failed to find device node for boot cpu\n");
84		return;
85	}
86	cpu_read_ops(dn, 0);
87}
88