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 #include <linux/acpi.h>
  14 #include <acpi/processor.h>
  15
  16 #include "internal.h"
  17
  18 #define PREFIX                  "ACPI: "
  19 #define _COMPONENT              ACPI_PROCESSOR_COMPONENT
  20 ACPI_MODULE_NAME("processor_core");
  21
  22 static int __init set_no_mwait(const struct dmi_system_id *id)
  23 {
  24         printk(KERN_NOTICE PREFIX "%s detected - "
  25                 "disabling mwait for CPU C-states\n", id->ident);
  26         boot_option_idle_override = IDLE_NOMWAIT;
  27         return 0;
  28 }
  29
  30 static struct dmi_system_id processor_idle_dmi_table[] __initdata = {
  31         {
  32         set_no_mwait, "Extensa 5220", {
  33         DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
  34         DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
  35         DMI_MATCH(DMI_PRODUCT_VERSION, "0100"),
  36         DMI_MATCH(DMI_BOARD_NAME, "Columbia") }, NULL},
  37         {},
  38 };
  39
  40 static int map_lapic_id(struct acpi_subtable_header *entry,
  41                  u32 acpi_id, int *apic_id)
  42 {
  43         struct acpi_madt_local_apic *lapic =
  44                 (struct acpi_madt_local_apic *)entry;
  45
  46         if (!(lapic->lapic_flags & ACPI_MADT_ENABLED))
  47                 return 0;
  48
  49         if (lapic->processor_id != acpi_id)
  50                 return 0;
  51
  52         *apic_id = lapic->id;
  53         return 1;
  54 }
  55
  56 static int map_x2apic_id(struct acpi_subtable_header *entry,
  57                          int device_declaration, u32 acpi_id, int *apic_id)
  58 {
  59         struct acpi_madt_local_x2apic *apic =
  60                 (struct acpi_madt_local_x2apic *)entry;
  61
  62         if (!(apic->lapic_flags & ACPI_MADT_ENABLED))
  63                 return 0;
  64
  65         if (device_declaration && (apic->uid == acpi_id)) {
  66                 *apic_id = apic->local_apic_id;
  67                 return 1;
  68         }
  69
  70         return 0;
  71 }
  72
  73 static int map_lsapic_id(struct acpi_subtable_header *entry,
  74                 int device_declaration, u32 acpi_id, int *apic_id)
  75 {
  76         struct acpi_madt_local_sapic *lsapic =
  77                 (struct acpi_madt_local_sapic *)entry;
  78
  79         if (!(lsapic->lapic_flags & ACPI_MADT_ENABLED))
  80                 return 0;
  81
  82         if (device_declaration) {
  83                 if ((entry->length < 16) || (lsapic->uid != acpi_id))
  84                         return 0;
  85         } else if (lsapic->processor_id != acpi_id)
  86                 return 0;
  87
  88         *apic_id = (lsapic->id << 8) | lsapic->eid;
  89         return 1;
  90 }
  91
  92 static int map_madt_entry(int type, u32 acpi_id)
  93 {
  94         unsigned long madt_end, entry;
  95         static struct acpi_table_madt *madt;
  96         static int read_madt;
  97         int apic_id = -1;
  98
  99         if (!read_madt) {
 100                 if (ACPI_FAILURE(acpi_get_table(ACPI_SIG_MADT, 0,
 101                                         (struct acpi_table_header **)&madt)))
 102                         madt = NULL;
 103                 read_madt++;
 104         }
 105
 106         if (!madt)
 107                 return apic_id;
 108
 109         entry = (unsigned long)madt;
 110         madt_end = entry + madt->header.length;
 111
 112         /* Parse all entries looking for a match. */
 113
 114         entry += sizeof(struct acpi_table_madt);
 115         while (entry + sizeof(struct acpi_subtable_header) < madt_end) {
 116                 struct acpi_subtable_header *header =
 117                         (struct acpi_subtable_header *)entry;
 118                 if (header->type == ACPI_MADT_TYPE_LOCAL_APIC) {
 119                         if (map_lapic_id(header, acpi_id, &apic_id))
 120                                 break;
 121                 } else if (header->type == ACPI_MADT_TYPE_LOCAL_X2APIC) {
 122                         if (map_x2apic_id(header, type, acpi_id, &apic_id))
 123                                 break;
 124                 } else if (header->type == ACPI_MADT_TYPE_LOCAL_SAPIC) {
 125                         if (map_lsapic_id(header, type, acpi_id, &apic_id))
 126                                 break;
 127                 }
 128                 entry += header->length;
 129         }
 130         return apic_id;
 131 }
 132
 133 static int map_mat_entry(acpi_handle handle, int type, u32 acpi_id)
 134 {
 135         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 136         union acpi_object *obj;
 137         struct acpi_subtable_header *header;
 138         int apic_id = -1;
 139
 140         if (ACPI_FAILURE(acpi_evaluate_object(handle, "_MAT", NULL, &buffer)))
 141                 goto exit;
 142
 143         if (!buffer.length || !buffer.pointer)
 144                 goto exit;
 145
 146         obj = buffer.pointer;
 147         if (obj->type != ACPI_TYPE_BUFFER ||
 148             obj->buffer.length < sizeof(struct acpi_subtable_header)) {
 149                 goto exit;
 150         }
 151
 152         header = (struct acpi_subtable_header *)obj->buffer.pointer;
 153         if (header->type == ACPI_MADT_TYPE_LOCAL_APIC) {
 154                 map_lapic_id(header, acpi_id, &apic_id);
 155         } else if (header->type == ACPI_MADT_TYPE_LOCAL_SAPIC) {
 156                 map_lsapic_id(header, type, acpi_id, &apic_id);
 157         }
 158
 159 exit:
 160         kfree(buffer.pointer);
 161         return apic_id;
 162 }
 163
 164 int acpi_get_apicid(acpi_handle handle, int type, u32 acpi_id)
 165 {
 166         int apic_id;
 167
 168         apic_id = map_mat_entry(handle, type, acpi_id);
 169         if (apic_id == -1)
 170                 apic_id = map_madt_entry(type, acpi_id);
 171
 172         return apic_id;
 173 }
 174
 175 int acpi_map_cpuid(int apic_id, u32 acpi_id)
 176 {
 177 #ifdef CONFIG_SMP
 178         int i;
 179 #endif
 180
 181         if (apic_id == -1) {
 182                 /*
 183                  * On UP processor, there is no _MAT or MADT table.
 184                  * So above apic_id is always set to -1.
 185                  *
 186                  * BIOS may define multiple CPU handles even for UP processor.
 187                  * For example,
 188                  *
 189                  * Scope (_PR)
 190                  * {
 191                  *     Processor (CPU0, 0x00, 0x00000410, 0x06) {}
 192                  *     Processor (CPU1, 0x01, 0x00000410, 0x06) {}
 193                  *     Processor (CPU2, 0x02, 0x00000410, 0x06) {}
 194                  *     Processor (CPU3, 0x03, 0x00000410, 0x06) {}
 195                  * }
 196                  *
 197                  * Ignores apic_id and always returns 0 for the processor
 198                  * handle with acpi id 0 if nr_cpu_ids is 1.
 199                  * This should be the case if SMP tables are not found.
 200                  * Return -1 for other CPU's handle.
 201                  */
 202                 if (nr_cpu_ids <= 1 && acpi_id == 0)
 203                         return acpi_id;
 204                 else
 205                         return apic_id;
 206         }
 207
 208 #ifdef CONFIG_SMP
 209         for_each_possible_cpu(i) {
 210                 if (cpu_physical_id(i) == apic_id)
 211                         return i;
 212         }
 213 #else
 214         /* In UP kernel, only processor 0 is valid */
 215         if (apic_id == 0)
 216                 return apic_id;
 217 #endif
 218         return -1;
 219 }
 220
 221 int acpi_get_cpuid(acpi_handle handle, int type, u32 acpi_id)
 222 {
 223         int apic_id;
 224
 225         apic_id = acpi_get_apicid(handle, type, acpi_id);
 226
 227         return acpi_map_cpuid(apic_id, acpi_id);
 228 }
 229 EXPORT_SYMBOL_GPL(acpi_get_cpuid);
 230
 231 static bool __init processor_physically_present(acpi_handle handle)
 232 {
 233         int cpuid, type;
 234         u32 acpi_id;
 235         acpi_status status;
 236         acpi_object_type acpi_type;
 237         unsigned long long tmp;
 238         union acpi_object object = { 0 };
 239         struct acpi_buffer buffer = { sizeof(union acpi_object), &object };
 240
 241         status = acpi_get_type(handle, &acpi_type);
 242         if (ACPI_FAILURE(status))
 243                 return false;
 244
 245         switch (acpi_type) {
 246         case ACPI_TYPE_PROCESSOR:
 247                 status = acpi_evaluate_object(handle, NULL, NULL, &buffer);
 248                 if (ACPI_FAILURE(status))
 249                         return false;
 250                 acpi_id = object.processor.proc_id;
 251                 break;
 252         case ACPI_TYPE_DEVICE:
 253                 status = acpi_evaluate_integer(handle, "_UID", NULL, &tmp);
 254                 if (ACPI_FAILURE(status))
 255                         return false;
 256                 acpi_id = tmp;
 257                 break;
 258         default:
 259                 return false;
 260         }
 261
 262         type = (acpi_type == ACPI_TYPE_DEVICE) ? 1 : 0;
 263         cpuid = acpi_get_cpuid(handle, type, acpi_id);
 264
 265         if (cpuid == -1)
 266                 return false;
 267
 268         return true;
 269 }
 270
 271 static void acpi_set_pdc_bits(u32 *buf)
 272 {
 273         buf[0] = ACPI_PDC_REVISION_ID;
 274         buf[1] = 1;
 275
 276         /* Enable coordination with firmware's _TSD info */
 277         buf[2] = ACPI_PDC_SMP_T_SWCOORD;
 278
 279         /* Twiddle arch-specific bits needed for _PDC */
 280         arch_acpi_set_pdc_bits(buf);
 281 }
 282
 283 static struct acpi_object_list *acpi_processor_alloc_pdc(void)
 284 {
 285         struct acpi_object_list *obj_list;
 286         union acpi_object *obj;
 287         u32 *buf;
 288
 289         /* allocate and initialize pdc. It will be used later. */
 290         obj_list = kmalloc(sizeof(struct acpi_object_list), GFP_KERNEL);
 291         if (!obj_list) {
 292                 printk(KERN_ERR "Memory allocation error\n");
 293                 return NULL;
 294         }
 295
 296         obj = kmalloc(sizeof(union acpi_object), GFP_KERNEL);
 297         if (!obj) {
 298                 printk(KERN_ERR "Memory allocation error\n");
 299                 kfree(obj_list);
 300                 return NULL;
 301         }
 302
 303         buf = kmalloc(12, GFP_KERNEL);
 304         if (!buf) {
 305                 printk(KERN_ERR "Memory allocation error\n");
 306                 kfree(obj);
 307                 kfree(obj_list);
 308                 return NULL;
 309         }
 310
 311         acpi_set_pdc_bits(buf);
 312
 313         obj->type = ACPI_TYPE_BUFFER;
 314         obj->buffer.length = 12;
 315         obj->buffer.pointer = (u8 *) buf;
 316         obj_list->count = 1;
 317         obj_list->pointer = obj;
 318
 319         return obj_list;
 320 }
 321
 322 /*
 323  * _PDC is required for a BIOS-OS handshake for most of the newer
 324  * ACPI processor features.
 325  */
 326 static int
 327 acpi_processor_eval_pdc(acpi_handle handle, struct acpi_object_list *pdc_in)
 328 {
 329         acpi_status status = AE_OK;
 330
 331         if (boot_option_idle_override == IDLE_NOMWAIT) {
 332                 /*
 333                  * If mwait is disabled for CPU C-states, the C2C3_FFH access
 334                  * mode will be disabled in the parameter of _PDC object.
 335                  * Of course C1_FFH access mode will also be disabled.
 336                  */
 337                 union acpi_object *obj;
 338                 u32 *buffer = NULL;
 339
 340                 obj = pdc_in->pointer;
 341                 buffer = (u32 *)(obj->buffer.pointer);
 342                 buffer[2] &= ~(ACPI_PDC_C_C2C3_FFH | ACPI_PDC_C_C1_FFH);
 343
 344         }
 345         status = acpi_evaluate_object(handle, "_PDC", pdc_in, NULL);
 346
 347         if (ACPI_FAILURE(status))
 348                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 349                     "Could not evaluate _PDC, using legacy perf. control.\n"));
 350
 351         return status;
 352 }
 353
 354 void acpi_processor_set_pdc(acpi_handle handle)
 355 {
 356         struct acpi_object_list *obj_list;
 357
 358         if (arch_has_acpi_pdc() == false)
 359                 return;
 360
 361         obj_list = acpi_processor_alloc_pdc();
 362         if (!obj_list)
 363                 return;
 364
 365         acpi_processor_eval_pdc(handle, obj_list);
 366
 367         kfree(obj_list->pointer->buffer.pointer);
 368         kfree(obj_list->pointer);
 369         kfree(obj_list);
 370 }
 371
 372 static acpi_status __init
 373 early_init_pdc(acpi_handle handle, u32 lvl, void *context, void **rv)
 374 {
 375         if (processor_physically_present(handle) == false)
 376                 return AE_OK;
 377
 378         acpi_processor_set_pdc(handle);
 379         return AE_OK;
 380 }
 381
 382 void __init acpi_early_processor_set_pdc(void)
 383 {
 384         /*
 385          * Check whether the system is DMI table. If yes, OSPM
 386          * should not use mwait for CPU-states.
 387          */
 388         dmi_check_system(processor_idle_dmi_table);
 389
 390         acpi_walk_namespace(ACPI_TYPE_PROCESSOR, ACPI_ROOT_OBJECT,
 391                             ACPI_UINT32_MAX,
 392                             early_init_pdc, NULL, NULL, NULL);
 393         acpi_get_devices("ACPI0007", early_init_pdc, NULL, NULL);
 394 }