diff options
Diffstat (limited to 'arch/arm64/kernel/cpu_ops.c')
-rw-r--r-- | arch/arm64/kernel/cpu_ops.c | 87 |
1 files changed, 87 insertions, 0 deletions
diff --git a/arch/arm64/kernel/cpu_ops.c b/arch/arm64/kernel/cpu_ops.c new file mode 100644 index 000000000..fb8ff9ba4 --- /dev/null +++ b/arch/arm64/kernel/cpu_ops.c @@ -0,0 +1,87 @@ +/* + * 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, +#endif + &cpu_psci_ops, + NULL, +}; + +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); +} |