linux/drivers/acpi/processor_core.c
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   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
  21ACPI_MODULE_NAME("processor_core");
  22
  23static 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
  31static 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
  41static 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
  57static 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
  74static 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
  93static 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
 134static 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
 160exit:
 161        if (buffer.pointer)
 162                kfree(buffer.pointer);
 163        return apic_id;
 164}
 165
 166int acpi_get_cpuid(acpi_handle handle, int type, u32 acpi_id)
 167{
 168#ifdef CONFIG_SMP
 169        int i;
 170#endif
 171        int apic_id = -1;
 172
 173        apic_id = map_mat_entry(handle, type, acpi_id);
 174        if (apic_id == -1)
 175                apic_id = map_madt_entry(type, acpi_id);
 176        if (apic_id == -1) {
 177                /*
 178                 * On UP processor, there is no _MAT or MADT table.
 179                 * So above apic_id is always set to -1.
 180                 *
 181                 * BIOS may define multiple CPU handles even for UP processor.
 182                 * For example,
 183                 *
 184                 * Scope (_PR)
 185                 * {
 186                 *     Processor (CPU0, 0x00, 0x00000410, 0x06) {}
 187                 *     Processor (CPU1, 0x01, 0x00000410, 0x06) {}
 188                 *     Processor (CPU2, 0x02, 0x00000410, 0x06) {}
 189                 *     Processor (CPU3, 0x03, 0x00000410, 0x06) {}
 190                 * }
 191                 *
 192                 * Ignores apic_id and always returns 0 for the processor
 193                 * handle with acpi id 0 if nr_cpu_ids is 1.
 194                 * This should be the case if SMP tables are not found.
 195                 * Return -1 for other CPU's handle.
 196                 */
 197                if (nr_cpu_ids <= 1 && acpi_id == 0)
 198                        return acpi_id;
 199                else
 200                        return apic_id;
 201        }
 202
 203#ifdef CONFIG_SMP
 204        for_each_possible_cpu(i) {
 205                if (cpu_physical_id(i) == apic_id)
 206                        return i;
 207        }
 208#else
 209        /* In UP kernel, only processor 0 is valid */
 210        if (apic_id == 0)
 211                return apic_id;
 212#endif
 213        return -1;
 214}
 215EXPORT_SYMBOL_GPL(acpi_get_cpuid);
 216
 217static bool __init processor_physically_present(acpi_handle handle)
 218{
 219        int cpuid, type;
 220        u32 acpi_id;
 221        acpi_status status;
 222        acpi_object_type acpi_type;
 223        unsigned long long tmp;
 224        union acpi_object object = { 0 };
 225        struct acpi_buffer buffer = { sizeof(union acpi_object), &object };
 226
 227        status = acpi_get_type(handle, &acpi_type);
 228        if (ACPI_FAILURE(status))
 229                return false;
 230
 231        switch (acpi_type) {
 232        case ACPI_TYPE_PROCESSOR:
 233                status = acpi_evaluate_object(handle, NULL, NULL, &buffer);
 234                if (ACPI_FAILURE(status))
 235                        return false;
 236                acpi_id = object.processor.proc_id;
 237                break;
 238        case ACPI_TYPE_DEVICE:
 239                status = acpi_evaluate_integer(handle, "_UID", NULL, &tmp);
 240                if (ACPI_FAILURE(status))
 241                        return false;
 242                acpi_id = tmp;
 243                break;
 244        default:
 245                return false;
 246        }
 247
 248        type = (acpi_type == ACPI_TYPE_DEVICE) ? 1 : 0;
 249        cpuid = acpi_get_cpuid(handle, type, acpi_id);
 250
 251        if (cpuid == -1)
 252                return false;
 253
 254        return true;
 255}
 256
 257static void __cpuinit acpi_set_pdc_bits(u32 *buf)
 258{
 259        buf[0] = ACPI_PDC_REVISION_ID;
 260        buf[1] = 1;
 261
 262        /* Enable coordination with firmware's _TSD info */
 263        buf[2] = ACPI_PDC_SMP_T_SWCOORD;
 264
 265        /* Twiddle arch-specific bits needed for _PDC */
 266        arch_acpi_set_pdc_bits(buf);
 267}
 268
 269static struct acpi_object_list *__cpuinit acpi_processor_alloc_pdc(void)
 270{
 271        struct acpi_object_list *obj_list;
 272        union acpi_object *obj;
 273        u32 *buf;
 274
 275        /* allocate and initialize pdc. It will be used later. */
 276        obj_list = kmalloc(sizeof(struct acpi_object_list), GFP_KERNEL);
 277        if (!obj_list) {
 278                printk(KERN_ERR "Memory allocation error\n");
 279                return NULL;
 280        }
 281
 282        obj = kmalloc(sizeof(union acpi_object), GFP_KERNEL);
 283        if (!obj) {
 284                printk(KERN_ERR "Memory allocation error\n");
 285                kfree(obj_list);
 286                return NULL;
 287        }
 288
 289        buf = kmalloc(12, GFP_KERNEL);
 290        if (!buf) {
 291                printk(KERN_ERR "Memory allocation error\n");
 292                kfree(obj);
 293                kfree(obj_list);
 294                return NULL;
 295        }
 296
 297        acpi_set_pdc_bits(buf);
 298
 299        obj->type = ACPI_TYPE_BUFFER;
 300        obj->buffer.length = 12;
 301        obj->buffer.pointer = (u8 *) buf;
 302        obj_list->count = 1;
 303        obj_list->pointer = obj;
 304
 305        return obj_list;
 306}
 307
 308/*
 309 * _PDC is required for a BIOS-OS handshake for most of the newer
 310 * ACPI processor features.
 311 */
 312static int __cpuinit
 313acpi_processor_eval_pdc(acpi_handle handle, struct acpi_object_list *pdc_in)
 314{
 315        acpi_status status = AE_OK;
 316
 317        if (boot_option_idle_override == IDLE_NOMWAIT) {
 318                /*
 319                 * If mwait is disabled for CPU C-states, the C2C3_FFH access
 320                 * mode will be disabled in the parameter of _PDC object.
 321                 * Of course C1_FFH access mode will also be disabled.
 322                 */
 323                union acpi_object *obj;
 324                u32 *buffer = NULL;
 325
 326                obj = pdc_in->pointer;
 327                buffer = (u32 *)(obj->buffer.pointer);
 328                buffer[2] &= ~(ACPI_PDC_C_C2C3_FFH | ACPI_PDC_C_C1_FFH);
 329
 330        }
 331        status = acpi_evaluate_object(handle, "_PDC", pdc_in, NULL);
 332
 333        if (ACPI_FAILURE(status))
 334                ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 335                    "Could not evaluate _PDC, using legacy perf. control.\n"));
 336
 337        return status;
 338}
 339
 340void __cpuinit acpi_processor_set_pdc(acpi_handle handle)
 341{
 342        struct acpi_object_list *obj_list;
 343
 344        if (arch_has_acpi_pdc() == false)
 345                return;
 346
 347        obj_list = acpi_processor_alloc_pdc();
 348        if (!obj_list)
 349                return;
 350
 351        acpi_processor_eval_pdc(handle, obj_list);
 352
 353        kfree(obj_list->pointer->buffer.pointer);
 354        kfree(obj_list->pointer);
 355        kfree(obj_list);
 356}
 357
 358static acpi_status __init
 359early_init_pdc(acpi_handle handle, u32 lvl, void *context, void **rv)
 360{
 361        if (processor_physically_present(handle) == false)
 362                return AE_OK;
 363
 364        acpi_processor_set_pdc(handle);
 365        return AE_OK;
 366}
 367
 368void __init acpi_early_processor_set_pdc(void)
 369{
 370        /*
 371         * Check whether the system is DMI table. If yes, OSPM
 372         * should not use mwait for CPU-states.
 373         */
 374        dmi_check_system(processor_idle_dmi_table);
 375
 376        acpi_walk_namespace(ACPI_TYPE_PROCESSOR, ACPI_ROOT_OBJECT,
 377                            ACPI_UINT32_MAX,
 378                            early_init_pdc, NULL, NULL, NULL);
 379        acpi_get_devices("ACPI0007", early_init_pdc, NULL, NULL);
 380}
 381
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