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 processor_idle_dmi_table[] __initdata = {
  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        kfree(buffer.pointer);
 162        return apic_id;
 163}
 164
 165int 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}
 214EXPORT_SYMBOL_GPL(acpi_get_cpuid);
 215
 216static 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
 256static 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
 268static 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 */
 311static int
 312acpi_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
 339void 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
 357static acpi_status __init
 358early_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
 367void __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}
 380
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