1 /* 2 * Copyright (C) 2005 Intel Corporation 3 * Copyright (C) 2009 Hewlett-Packard Development Company, L.P. 4 * 5 * Alex Chiang <achiang@hp.com> 6 * - Unified x86/ia64 implementations 7 */ 8 #include <linux/export.h> 9 #include <linux/acpi.h> 10 #include <acpi/processor.h> 11 12 #define _COMPONENT ACPI_PROCESSOR_COMPONENT 13 ACPI_MODULE_NAME("processor_core"); 14 15 static int map_lapic_id(struct acpi_subtable_header *entry, 16 u32 acpi_id, int *apic_id) 17 { 18 struct acpi_madt_local_apic *lapic = 19 (struct acpi_madt_local_apic *)entry; 20 21 if (!(lapic->lapic_flags & ACPI_MADT_ENABLED)) 22 return -ENODEV; 23 24 if (lapic->processor_id != acpi_id) 25 return -EINVAL; 26 27 *apic_id = lapic->id; 28 return 0; 29 } 30 31 static int map_x2apic_id(struct acpi_subtable_header *entry, 32 int device_declaration, u32 acpi_id, int *apic_id) 33 { 34 struct acpi_madt_local_x2apic *apic = 35 (struct acpi_madt_local_x2apic *)entry; 36 37 if (!(apic->lapic_flags & ACPI_MADT_ENABLED)) 38 return -ENODEV; 39 40 if (device_declaration && (apic->uid == acpi_id)) { 41 *apic_id = apic->local_apic_id; 42 return 0; 43 } 44 45 return -EINVAL; 46 } 47 48 static int map_lsapic_id(struct acpi_subtable_header *entry, 49 int device_declaration, u32 acpi_id, int *apic_id) 50 { 51 struct acpi_madt_local_sapic *lsapic = 52 (struct acpi_madt_local_sapic *)entry; 53 54 if (!(lsapic->lapic_flags & ACPI_MADT_ENABLED)) 55 return -ENODEV; 56 57 if (device_declaration) { 58 if ((entry->length < 16) || (lsapic->uid != acpi_id)) 59 return -EINVAL; 60 } else if (lsapic->processor_id != acpi_id) 61 return -EINVAL; 62 63 *apic_id = (lsapic->id << 8) | lsapic->eid; 64 return 0; 65 } 66 67 static int map_madt_entry(int type, u32 acpi_id) 68 { 69 unsigned long madt_end, entry; 70 static struct acpi_table_madt *madt; 71 static int read_madt; 72 int apic_id = -1; 73 74 if (!read_madt) { 75 if (ACPI_FAILURE(acpi_get_table(ACPI_SIG_MADT, 0, 76 (struct acpi_table_header **)&madt))) 77 madt = NULL; 78 read_madt++; 79 } 80 81 if (!madt) 82 return apic_id; 83 84 entry = (unsigned long)madt; 85 madt_end = entry + madt->header.length; 86 87 /* Parse all entries looking for a match. */ 88 89 entry += sizeof(struct acpi_table_madt); 90 while (entry + sizeof(struct acpi_subtable_header) < madt_end) { 91 struct acpi_subtable_header *header = 92 (struct acpi_subtable_header *)entry; 93 if (header->type == ACPI_MADT_TYPE_LOCAL_APIC) { 94 if (!map_lapic_id(header, acpi_id, &apic_id)) 95 break; 96 } else if (header->type == ACPI_MADT_TYPE_LOCAL_X2APIC) { 97 if (!map_x2apic_id(header, type, acpi_id, &apic_id)) 98 break; 99 } else if (header->type == ACPI_MADT_TYPE_LOCAL_SAPIC) { 100 if (!map_lsapic_id(header, type, acpi_id, &apic_id)) 101 break; 102 } 103 entry += header->length; 104 } 105 return apic_id; 106 } 107 108 static int map_mat_entry(acpi_handle handle, int type, u32 acpi_id) 109 { 110 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; 111 union acpi_object *obj; 112 struct acpi_subtable_header *header; 113 int apic_id = -1; 114 115 if (ACPI_FAILURE(acpi_evaluate_object(handle, "_MAT", NULL, &buffer))) 116 goto exit; 117 118 if (!buffer.length || !buffer.pointer) 119 goto exit; 120 121 obj = buffer.pointer; 122 if (obj->type != ACPI_TYPE_BUFFER || 123 obj->buffer.length < sizeof(struct acpi_subtable_header)) { 124 goto exit; 125 } 126 127 header = (struct acpi_subtable_header *)obj->buffer.pointer; 128 if (header->type == ACPI_MADT_TYPE_LOCAL_APIC) { 129 map_lapic_id(header, acpi_id, &apic_id); 130 } else if (header->type == ACPI_MADT_TYPE_LOCAL_SAPIC) { 131 map_lsapic_id(header, type, acpi_id, &apic_id); 132 } else if (header->type == ACPI_MADT_TYPE_LOCAL_X2APIC) { 133 map_x2apic_id(header, type, acpi_id, &apic_id); 134 } 135 136 exit: 137 kfree(buffer.pointer); 138 return apic_id; 139 } 140 141 int acpi_get_apicid(acpi_handle handle, int type, u32 acpi_id) 142 { 143 int apic_id; 144 145 apic_id = map_mat_entry(handle, type, acpi_id); 146 if (apic_id == -1) 147 apic_id = map_madt_entry(type, acpi_id); 148 149 return apic_id; 150 } 151 152 int acpi_map_cpuid(int apic_id, u32 acpi_id) 153 { 154 #ifdef CONFIG_SMP 155 int i; 156 #endif 157 158 if (apic_id == -1) { 159 /* 160 * On UP processor, there is no _MAT or MADT table. 161 * So above apic_id is always set to -1. 162 * 163 * BIOS may define multiple CPU handles even for UP processor. 164 * For example, 165 * 166 * Scope (_PR) 167 * { 168 * Processor (CPU0, 0x00, 0x00000410, 0x06) {} 169 * Processor (CPU1, 0x01, 0x00000410, 0x06) {} 170 * Processor (CPU2, 0x02, 0x00000410, 0x06) {} 171 * Processor (CPU3, 0x03, 0x00000410, 0x06) {} 172 * } 173 * 174 * Ignores apic_id and always returns 0 for the processor 175 * handle with acpi id 0 if nr_cpu_ids is 1. 176 * This should be the case if SMP tables are not found. 177 * Return -1 for other CPU's handle. 178 */ 179 if (nr_cpu_ids <= 1 && acpi_id == 0) 180 return acpi_id; 181 else 182 return apic_id; 183 } 184 185 #ifdef CONFIG_SMP 186 for_each_possible_cpu(i) { 187 if (cpu_physical_id(i) == apic_id) 188 return i; 189 } 190 #else 191 /* In UP kernel, only processor 0 is valid */ 192 if (apic_id == 0) 193 return apic_id; 194 #endif 195 return -1; 196 } 197 198 int acpi_get_cpuid(acpi_handle handle, int type, u32 acpi_id) 199 { 200 int apic_id; 201 202 apic_id = acpi_get_apicid(handle, type, acpi_id); 203 204 return acpi_map_cpuid(apic_id, acpi_id); 205 } 206 EXPORT_SYMBOL_GPL(acpi_get_cpuid); 207