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  *      Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
   8  *      - Added _PDC for platforms with Intel CPUs
   9  */
  10 #include <linux/export.h>
  11 #include <linux/dmi.h>
  12 #include <linux/slab.h>
  13
  14 #include <acpi/acpi_drivers.h>
  15 #include <acpi/processor.h>
  16
  17 #include "internal.h"
  18
  19 #define PREFIX                  "ACPI: "
  20 #define _COMPONENT              ACPI_PROCESSOR_COMPONENT
  21 ACPI_MODULE_NAME("processor_core");
  22
  23 static int __init set_no_mwait(const struct dmi_system_id *id)
  24 {
  25         printk(KERN_NOTICE PREFIX "%s detected - "
  26                 "disabling mwait for CPU C-states\n", id->ident);
  27         boot_option_idle_override = IDLE_NOMWAIT;
  28         return 0;
  29 }
  30
  31 static struct dmi_system_id __initdata processor_idle_dmi_table[] = {
  32         {
  33         set_no_mwait, "Extensa 5220", {
  34         DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
  35         DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
  36         DMI_MATCH(DMI_PRODUCT_VERSION, "0100"),
  37         DMI_MATCH(DMI_BOARD_NAME, "Columbia") }, NULL},
  38         {},
  39 };
  40
  41 static int map_lapic_id(struct acpi_subtable_header *entry,
  42                  u32 acpi_id, int *apic_id)
  43 {
  44         struct acpi_madt_local_apic *lapic =
  45                 (struct acpi_madt_local_apic *)entry;
  46
  47         if (!(lapic->lapic_flags & ACPI_MADT_ENABLED))
  48                 return 0;
  49
  50         if (lapic->processor_id != acpi_id)
  51                 return 0;
  52
  53         *apic_id = lapic->id;
  54         return 1;
  55 }
  56
  57 static int map_x2apic_id(struct acpi_subtable_header *entry,
  58                          int device_declaration, u32 acpi_id, int *apic_id)
  59 {
  60         struct acpi_madt_local_x2apic *apic =
  61                 (struct acpi_madt_local_x2apic *)entry;
  62
  63         if (!(apic->lapic_flags & ACPI_MADT_ENABLED))
  64                 return 0;
  65
  66         if (device_declaration && (apic->uid == acpi_id)) {
  67                 *apic_id = apic->local_apic_id;
  68                 return 1;
  69         }
  70
  71         return 0;
  72 }
  73
  74 static int map_lsapic_id(struct acpi_subtable_header *entry,
  75                 int device_declaration, u32 acpi_id, int *apic_id)
  76 {
  77         struct acpi_madt_local_sapic *lsapic =
  78                 (struct acpi_madt_local_sapic *)entry;
  79
  80         if (!(lsapic->lapic_flags & ACPI_MADT_ENABLED))
  81                 return 0;
  82
  83         if (device_declaration) {
  84                 if ((entry->length < 16) || (lsapic->uid != acpi_id))
  85                         return 0;
  86         } else if (lsapic->processor_id != acpi_id)
  87                 return 0;
  88
  89         *apic_id = (lsapic->id << 8) | lsapic->eid;
  90         return 1;
  91 }
  92
  93 static int map_madt_entry(int type, u32 acpi_id)
  94 {
  95         unsigned long madt_end, entry;
  96         static struct acpi_table_madt *madt;
  97         static int read_madt;
  98         int apic_id = -1;
  99
 100         if (!read_madt) {
 101                 if (ACPI_FAILURE(acpi_get_table(ACPI_SIG_MADT, 0,
 102                                         (struct acpi_table_header **)&madt)))
 103                         madt = NULL;
 104                 read_madt++;
 105         }
 106
 107         if (!madt)
 108                 return apic_id;
 109
 110         entry = (unsigned long)madt;
 111         madt_end = entry + madt->header.length;
 112
 113         /* Parse all entries looking for a match. */
 114
 115         entry += sizeof(struct acpi_table_madt);
 116         while (entry + sizeof(struct acpi_subtable_header) < madt_end) {
 117                 struct acpi_subtable_header *header =
 118                         (struct acpi_subtable_header *)entry;
 119                 if (header->type == ACPI_MADT_TYPE_LOCAL_APIC) {
 120                         if (map_lapic_id(header, acpi_id, &apic_id))
 121                                 break;
 122                 } else if (header->type == ACPI_MADT_TYPE_LOCAL_X2APIC) {
 123                         if (map_x2apic_id(header, type, acpi_id, &apic_id))
 124                                 break;
 125                 } else if (header->type == ACPI_MADT_TYPE_LOCAL_SAPIC) {
 126                         if (map_lsapic_id(header, type, acpi_id, &apic_id))
 127                                 break;
 128                 }
 129                 entry += header->length;
 130         }
 131         return apic_id;
 132 }
 133
 134 static int map_mat_entry(acpi_handle handle, int type, u32 acpi_id)
 135 {
 136         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 137         union acpi_object *obj;
 138         struct acpi_subtable_header *header;
 139         int apic_id = -1;
 140
 141         if (ACPI_FAILURE(acpi_evaluate_object(handle, "_MAT", NULL, &buffer)))
 142                 goto exit;
 143
 144         if (!buffer.length || !buffer.pointer)
 145                 goto exit;
 146
 147         obj = buffer.pointer;
 148         if (obj->type != ACPI_TYPE_BUFFER ||
 149             obj->buffer.length < sizeof(struct acpi_subtable_header)) {
 150                 goto exit;
 151         }
 152
 153         header = (struct acpi_subtable_header *)obj->buffer.pointer;
 154         if (header->type == ACPI_MADT_TYPE_LOCAL_APIC) {
 155                 map_lapic_id(header, acpi_id, &apic_id);
 156         } else if (header->type == ACPI_MADT_TYPE_LOCAL_SAPIC) {
 157                 map_lsapic_id(header, type, acpi_id, &apic_id);
 158         }
 159
 160 exit:
 161         kfree(buffer.pointer);
 162         return apic_id;
 163 }
 164
 165 int acpi_get_cpuid(acpi_handle handle, int type, u32 acpi_id)
 166 {
 167 #ifdef CONFIG_SMP
 168         int i;
 169 #endif
 170         int apic_id = -1;
 171
 172         apic_id = map_mat_entry(handle, type, acpi_id);
 173         if (apic_id == -1)
 174                 apic_id = map_madt_entry(type, acpi_id);
 175         if (apic_id == -1) {
 176                 /*
 177                  * On UP processor, there is no _MAT or MADT table.
 178                  * So above apic_id is always set to -1.
 179                  *
 180                  * BIOS may define multiple CPU handles even for UP processor.
 181                  * For example,
 182                  *
 183                  * Scope (_PR)
 184                  * {
 185                  *     Processor (CPU0, 0x00, 0x00000410, 0x06) {}
 186                  *     Processor (CPU1, 0x01, 0x00000410, 0x06) {}
 187                  *     Processor (CPU2, 0x02, 0x00000410, 0x06) {}
 188                  *     Processor (CPU3, 0x03, 0x00000410, 0x06) {}
 189                  * }
 190                  *
 191                  * Ignores apic_id and always returns 0 for the processor
 192                  * handle with acpi id 0 if nr_cpu_ids is 1.
 193                  * This should be the case if SMP tables are not found.
 194                  * Return -1 for other CPU's handle.
 195                  */
 196                 if (nr_cpu_ids <= 1 && acpi_id == 0)
 197                         return acpi_id;
 198                 else
 199                         return apic_id;
 200         }
 201
 202 #ifdef CONFIG_SMP
 203         for_each_possible_cpu(i) {
 204                 if (cpu_physical_id(i) == apic_id)
 205                         return i;
 206         }
 207 #else
 208         /* In UP kernel, only processor 0 is valid */
 209         if (apic_id == 0)
 210                 return apic_id;
 211 #endif
 212         return -1;
 213 }
 214 EXPORT_SYMBOL_GPL(acpi_get_cpuid);
 215
 216 static bool __init processor_physically_present(acpi_handle handle)
 217 {
 218         int cpuid, type;
 219         u32 acpi_id;
 220         acpi_status status;
 221         acpi_object_type acpi_type;
 222         unsigned long long tmp;
 223         union acpi_object object = { 0 };
 224         struct acpi_buffer buffer = { sizeof(union acpi_object), &object };
 225
 226         status = acpi_get_type(handle, &acpi_type);
 227         if (ACPI_FAILURE(status))
 228                 return false;
 229
 230         switch (acpi_type) {
 231         case ACPI_TYPE_PROCESSOR:
 232                 status = acpi_evaluate_object(handle, NULL, NULL, &buffer);
 233                 if (ACPI_FAILURE(status))
 234                         return false;
 235                 acpi_id = object.processor.proc_id;
 236                 break;
 237         case ACPI_TYPE_DEVICE:
 238                 status = acpi_evaluate_integer(handle, "_UID", NULL, &tmp);
 239                 if (ACPI_FAILURE(status))
 240                         return false;
 241                 acpi_id = tmp;
 242                 break;
 243         default:
 244                 return false;
 245         }
 246
 247         type = (acpi_type == ACPI_TYPE_DEVICE) ? 1 : 0;
 248         cpuid = acpi_get_cpuid(handle, type, acpi_id);
 249
 250         if (cpuid == -1)
 251                 return false;
 252
 253         return true;
 254 }
 255
 256 static void acpi_set_pdc_bits(u32 *buf)
 257 {
 258         buf[0] = ACPI_PDC_REVISION_ID;
 259         buf[1] = 1;
 260
 261         /* Enable coordination with firmware's _TSD info */
 262         buf[2] = ACPI_PDC_SMP_T_SWCOORD;
 263
 264         /* Twiddle arch-specific bits needed for _PDC */
 265         arch_acpi_set_pdc_bits(buf);
 266 }
 267
 268 static struct acpi_object_list *acpi_processor_alloc_pdc(void)
 269 {
 270         struct acpi_object_list *obj_list;
 271         union acpi_object *obj;
 272         u32 *buf;
 273
 274         /* allocate and initialize pdc. It will be used later. */
 275         obj_list = kmalloc(sizeof(struct acpi_object_list), GFP_KERNEL);
 276         if (!obj_list) {
 277                 printk(KERN_ERR "Memory allocation error\n");
 278                 return NULL;
 279         }
 280
 281         obj = kmalloc(sizeof(union acpi_object), GFP_KERNEL);
 282         if (!obj) {
 283                 printk(KERN_ERR "Memory allocation error\n");
 284                 kfree(obj_list);
 285                 return NULL;
 286         }
 287
 288         buf = kmalloc(12, GFP_KERNEL);
 289         if (!buf) {
 290                 printk(KERN_ERR "Memory allocation error\n");
 291                 kfree(obj);
 292                 kfree(obj_list);
 293                 return NULL;
 294         }
 295
 296         acpi_set_pdc_bits(buf);
 297
 298         obj->type = ACPI_TYPE_BUFFER;
 299         obj->buffer.length = 12;
 300         obj->buffer.pointer = (u8 *) buf;
 301         obj_list->count = 1;
 302         obj_list->pointer = obj;
 303
 304         return obj_list;
 305 }
 306
 307 /*
 308  * _PDC is required for a BIOS-OS handshake for most of the newer
 309  * ACPI processor features.
 310  */
 311 static int
 312 acpi_processor_eval_pdc(acpi_handle handle, struct acpi_object_list *pdc_in)
 313 {
 314         acpi_status status = AE_OK;
 315
 316         if (boot_option_idle_override == IDLE_NOMWAIT) {
 317                 /*
 318                  * If mwait is disabled for CPU C-states, the C2C3_FFH access
 319                  * mode will be disabled in the parameter of _PDC object.
 320                  * Of course C1_FFH access mode will also be disabled.
 321                  */
 322                 union acpi_object *obj;
 323                 u32 *buffer = NULL;
 324
 325                 obj = pdc_in->pointer;
 326                 buffer = (u32 *)(obj->buffer.pointer);
 327                 buffer[2] &= ~(ACPI_PDC_C_C2C3_FFH | ACPI_PDC_C_C1_FFH);
 328
 329         }
 330         status = acpi_evaluate_object(handle, "_PDC", pdc_in, NULL);
 331
 332         if (ACPI_FAILURE(status))
 333                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 334                     "Could not evaluate _PDC, using legacy perf. control.\n"));
 335
 336         return status;
 337 }
 338
 339 void acpi_processor_set_pdc(acpi_handle handle)
 340 {
 341         struct acpi_object_list *obj_list;
 342
 343         if (arch_has_acpi_pdc() == false)
 344                 return;
 345
 346         obj_list = acpi_processor_alloc_pdc();
 347         if (!obj_list)
 348                 return;
 349
 350         acpi_processor_eval_pdc(handle, obj_list);
 351
 352         kfree(obj_list->pointer->buffer.pointer);
 353         kfree(obj_list->pointer);
 354         kfree(obj_list);
 355 }
 356
 357 static acpi_status __init
 358 early_init_pdc(acpi_handle handle, u32 lvl, void *context, void **rv)
 359 {
 360         if (processor_physically_present(handle) == false)
 361                 return AE_OK;
 362
 363         acpi_processor_set_pdc(handle);
 364         return AE_OK;
 365 }
 366
 367 void __init acpi_early_processor_set_pdc(void)
 368 {
 369         /*
 370          * Check whether the system is DMI table. If yes, OSPM
 371          * should not use mwait for CPU-states.
 372          */
 373         dmi_check_system(processor_idle_dmi_table);
 374
 375         acpi_walk_namespace(ACPI_TYPE_PROCESSOR, ACPI_ROOT_OBJECT,
 376                             ACPI_UINT32_MAX,
 377                             early_init_pdc, NULL, NULL, NULL);
 378         acpi_get_devices("ACPI0007", early_init_pdc, NULL, NULL);
 379 }