drivers/acpi/processor_core.c

   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         }
 133
 134 exit:
 135         kfree(buffer.pointer);
 136         return apic_id;
 137 }
 138
 139 int acpi_get_apicid(acpi_handle handle, int type, u32 acpi_id)
 140 {
 141         int apic_id;
 142
 143         apic_id = map_mat_entry(handle, type, acpi_id);
 144         if (apic_id == -1)
 145                 apic_id = map_madt_entry(type, acpi_id);
 146
 147         return apic_id;
 148 }
 149
 150 int acpi_map_cpuid(int apic_id, u32 acpi_id)
 151 {
 152 #ifdef CONFIG_SMP
 153         int i;
 154 #endif
 155
 156         if (apic_id == -1) {
 157                 /*
 158                  * On UP processor, there is no _MAT or MADT table.
 159                  * So above apic_id is always set to -1.
 160                  *
 161                  * BIOS may define multiple CPU handles even for UP processor.
 162                  * For example,
 163                  *
 164                  * Scope (_PR)
 165                  * {
 166                  *     Processor (CPU0, 0x00, 0x00000410, 0x06) {}
 167                  *     Processor (CPU1, 0x01, 0x00000410, 0x06) {}
 168                  *     Processor (CPU2, 0x02, 0x00000410, 0x06) {}
 169                  *     Processor (CPU3, 0x03, 0x00000410, 0x06) {}
 170                  * }
 171                  *
 172                  * Ignores apic_id and always returns 0 for the processor
 173                  * handle with acpi id 0 if nr_cpu_ids is 1.
 174                  * This should be the case if SMP tables are not found.
 175                  * Return -1 for other CPU's handle.
 176                  */
 177                 if (nr_cpu_ids <= 1 && acpi_id == 0)
 178                         return acpi_id;
 179                 else
 180                         return apic_id;
 181         }
 182
 183 #ifdef CONFIG_SMP
 184         for_each_possible_cpu(i) {
 185                 if (cpu_physical_id(i) == apic_id)
 186                         return i;
 187         }
 188 #else
 189         /* In UP kernel, only processor 0 is valid */
 190         if (apic_id == 0)
 191                 return apic_id;
 192 #endif
 193         return -1;
 194 }
 195
 196 int acpi_get_cpuid(acpi_handle handle, int type, u32 acpi_id)
 197 {
 198         int apic_id;
 199
 200         apic_id = acpi_get_apicid(handle, type, acpi_id);
 201
 202         return acpi_map_cpuid(apic_id, acpi_id);
 203 }
 204 EXPORT_SYMBOL_GPL(acpi_get_cpuid);