| 1 | |
| 2 | |
| 3 | * CPU kernel entry/exit control
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| 4 | *
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| 5 | * Copyright (C) 2013 ARM Ltd.
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| 6 |
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| 7 |
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| 8 | #include <linux/acpi.h>
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| 9 | #include <linux/cache.h>
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| 10 | #include <linux/errno.h>
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| 11 | #include <linux/of.h>
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| 12 | #include <linux/string.h>
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| 13 | #include <asm/acpi.h>
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| 14 | #include <asm/cpu_ops.h>
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| 15 | #include <asm/smp_plat.h>
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| 16 |
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| 17 | extern const struct cpu_operations smp_spin_table_ops;
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| 18 | #ifdef CONFIG_ARM64_ACPI_PARKING_PROTOCOL
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| 19 | extern const struct cpu_operations acpi_parking_protocol_ops;
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| 20 | #endif
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| 21 | extern const struct cpu_operations cpu_psci_ops;
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| 22 |
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| 23 | static const struct cpu_operations *cpu_ops[NR_CPUS] __ro_after_init;
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| 24 |
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| 25 | static const struct cpu_operations *const dt_supported_cpu_ops[] __initconst = {
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| 26 | &smp_spin_table_ops,
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| 27 | &cpu_psci_ops,
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| 28 | NULL,
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| 29 | };
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| 30 |
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| 31 | static const struct cpu_operations *const acpi_supported_cpu_ops[] __initconst = {
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| 32 | #ifdef CONFIG_ARM64_ACPI_PARKING_PROTOCOL
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| 33 | &acpi_parking_protocol_ops,
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| 34 | #endif
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| 35 | &cpu_psci_ops,
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| 36 | NULL,
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| 37 | };
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| 38 |
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| 39 | static const struct cpu_operations * __init cpu_get_ops(const char *name)
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| 40 | {
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| 41 | const struct cpu_operations *const *ops;
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| 42 |
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| 43 | ops = acpi_disabled ? dt_supported_cpu_ops : acpi_supported_cpu_ops;
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| 44 |
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| 45 | while (*ops) {
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| 46 | if (!strcmp(name, (*ops)->name))
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| 47 | return *ops;
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| 48 |
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| 49 | ops++;
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| 50 | }
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| 51 |
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| 52 | return NULL;
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| 53 | }
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| 54 |
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| 55 | static const char *__init cpu_read_enable_method(int cpu)
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| 56 | {
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| 57 | const char *enable_method;
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| 58 |
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| 59 | if (acpi_disabled) {
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| 60 | struct device_node *dn = of_get_cpu_node(cpu, NULL);
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| 61 |
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| 62 | if (!dn) {
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| 63 | if (!cpu)
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| 64 | pr_err("Failed to find device node for boot cpu\n");
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| 65 | return NULL;
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| 66 | }
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| 67 |
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| 68 | enable_method = of_get_property(dn, "enable-method", NULL);
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| 69 | if (!enable_method) {
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| 70 | |
| 71 | * The boot CPU may not have an enable method (e.g.
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| 72 | * when spin-table is used for secondaries).
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| 73 | * Don't warn spuriously.
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| 74 |
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| 75 | if (cpu != 0)
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| 76 | pr_err("%pOF: missing enable-method property\n",
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| 77 | dn);
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| 78 | }
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| 79 | of_node_put(dn);
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| 80 | } else {
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| 81 | enable_method = acpi_get_enable_method(cpu);
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| 82 | if (!enable_method) {
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| 83 | |
| 84 | * In ACPI systems the boot CPU does not require
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| 85 | * checking the enable method since for some
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| 86 | * boot protocol (ie parking protocol) it need not
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| 87 | * be initialized. Don't warn spuriously.
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| 88 |
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| 89 | if (cpu != 0)
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| 90 | pr_err("Unsupported ACPI enable-method\n");
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| 91 | }
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| 92 | }
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| 93 |
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| 94 | return enable_method;
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| 95 | }
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| 96 | |
| 97 | * Read a cpu's enable method and record it in cpu_ops.
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| 98 |
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| 99 | int __init init_cpu_ops(int cpu)
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| 100 | {
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| 101 | const char *enable_method = cpu_read_enable_method(cpu);
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| 102 |
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| 103 | if (!enable_method)
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| 104 | return -ENODEV;
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| 105 |
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| 106 | cpu_ops[cpu] = cpu_get_ops(enable_method);
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| 107 | if (!cpu_ops[cpu]) {
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| 108 | pr_warn("Unsupported enable-method: %s\n", enable_method);
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| 109 | return -EOPNOTSUPP;
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| 110 | }
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| 111 |
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| 112 | return 0;
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| 113 | }
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| 114 |
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| 115 | const struct cpu_operations *get_cpu_ops(int cpu)
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| 116 | {
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| 117 | return cpu_ops[cpu];
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| 118 | }
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