123 lines
3 KiB
C
123 lines
3 KiB
C
/*
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* CPU kernel entry/exit control
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*
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* Copyright (C) 2013 ARM Ltd.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include <linux/acpi.h>
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#include <linux/cache.h>
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#include <linux/errno.h>
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#include <linux/of.h>
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#include <linux/string.h>
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#include <asm/acpi.h>
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#include <asm/cpu_ops.h>
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#include <asm/smp_plat.h>
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extern const struct cpu_operations smp_spin_table_ops;
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extern const struct cpu_operations acpi_parking_protocol_ops;
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extern const struct cpu_operations cpu_psci_ops;
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const struct cpu_operations *cpu_ops[NR_CPUS] __ro_after_init;
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static const struct cpu_operations *const dt_supported_cpu_ops[] __initconst = {
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&smp_spin_table_ops,
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&cpu_psci_ops,
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NULL,
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};
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static const struct cpu_operations *const acpi_supported_cpu_ops[] __initconst = {
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#ifdef CONFIG_ARM64_ACPI_PARKING_PROTOCOL
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&acpi_parking_protocol_ops,
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#endif
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&cpu_psci_ops,
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NULL,
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};
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static const struct cpu_operations * __init cpu_get_ops(const char *name)
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{
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const struct cpu_operations *const *ops;
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ops = acpi_disabled ? dt_supported_cpu_ops : acpi_supported_cpu_ops;
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while (*ops) {
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if (!strcmp(name, (*ops)->name))
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return *ops;
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ops++;
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}
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return NULL;
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}
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static const char *__init cpu_read_enable_method(int cpu)
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{
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const char *enable_method;
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if (acpi_disabled) {
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struct device_node *dn = of_get_cpu_node(cpu, NULL);
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if (!dn) {
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if (!cpu)
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pr_err("Failed to find device node for boot cpu\n");
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return NULL;
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}
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enable_method = of_get_property(dn, "enable-method", NULL);
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if (!enable_method) {
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/*
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* The boot CPU may not have an enable method (e.g.
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* when spin-table is used for secondaries).
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* Don't warn spuriously.
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*/
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if (cpu != 0)
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pr_err("%pOF: missing enable-method property\n",
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dn);
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}
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of_node_put(dn);
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} else {
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enable_method = acpi_get_enable_method(cpu);
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if (!enable_method) {
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/*
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* In ACPI systems the boot CPU does not require
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* checking the enable method since for some
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* boot protocol (ie parking protocol) it need not
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* be initialized. Don't warn spuriously.
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*/
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if (cpu != 0)
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pr_err("Unsupported ACPI enable-method\n");
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}
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}
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return enable_method;
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}
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/*
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* Read a cpu's enable method and record it in cpu_ops.
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*/
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int __init cpu_read_ops(int cpu)
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{
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const char *enable_method = cpu_read_enable_method(cpu);
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if (!enable_method)
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return -ENODEV;
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cpu_ops[cpu] = cpu_get_ops(enable_method);
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if (!cpu_ops[cpu]) {
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pr_warn("Unsupported enable-method: %s\n", enable_method);
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return -EOPNOTSUPP;
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}
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return 0;
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}
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