linux/drivers/acpi/acpi_processor.c
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   1/*
   2 * acpi_processor.c - ACPI processor enumeration support
   3 *
   4 * Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
   5 * Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
   6 * Copyright (C) 2004       Dominik Brodowski <linux@brodo.de>
   7 * Copyright (C) 2004  Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
   8 * Copyright (C) 2013, Intel Corporation
   9 *                     Rafael J. Wysocki <rafael.j.wysocki@intel.com>
  10 *
  11 * This program is free software; you can redistribute it and/or modify it
  12 * under the terms of the GNU General Public License version 2 as published
  13 * by the Free Software Foundation.
  14 */
  15
  16#include <linux/acpi.h>
  17#include <linux/device.h>
  18#include <linux/kernel.h>
  19#include <linux/module.h>
  20#include <linux/pci.h>
  21
  22#include <acpi/processor.h>
  23
  24#include <asm/cpu.h>
  25
  26#include "internal.h"
  27
  28#define _COMPONENT      ACPI_PROCESSOR_COMPONENT
  29
  30ACPI_MODULE_NAME("processor");
  31
  32DEFINE_PER_CPU(struct acpi_processor *, processors);
  33EXPORT_PER_CPU_SYMBOL(processors);
  34
  35/* --------------------------------------------------------------------------
  36                                Errata Handling
  37   -------------------------------------------------------------------------- */
  38
  39struct acpi_processor_errata errata __read_mostly;
  40EXPORT_SYMBOL_GPL(errata);
  41
  42static int acpi_processor_errata_piix4(struct pci_dev *dev)
  43{
  44        u8 value1 = 0;
  45        u8 value2 = 0;
  46
  47
  48        if (!dev)
  49                return -EINVAL;
  50
  51        /*
  52         * Note that 'dev' references the PIIX4 ACPI Controller.
  53         */
  54
  55        switch (dev->revision) {
  56        case 0:
  57                ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found PIIX4 A-step\n"));
  58                break;
  59        case 1:
  60                ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found PIIX4 B-step\n"));
  61                break;
  62        case 2:
  63                ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found PIIX4E\n"));
  64                break;
  65        case 3:
  66                ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found PIIX4M\n"));
  67                break;
  68        default:
  69                ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found unknown PIIX4\n"));
  70                break;
  71        }
  72
  73        switch (dev->revision) {
  74
  75        case 0:         /* PIIX4 A-step */
  76        case 1:         /* PIIX4 B-step */
  77                /*
  78                 * See specification changes #13 ("Manual Throttle Duty Cycle")
  79                 * and #14 ("Enabling and Disabling Manual Throttle"), plus
  80                 * erratum #5 ("STPCLK# Deassertion Time") from the January
  81                 * 2002 PIIX4 specification update.  Applies to only older
  82                 * PIIX4 models.
  83                 */
  84                errata.piix4.throttle = 1;
  85
  86        case 2:         /* PIIX4E */
  87        case 3:         /* PIIX4M */
  88                /*
  89                 * See erratum #18 ("C3 Power State/BMIDE and Type-F DMA
  90                 * Livelock") from the January 2002 PIIX4 specification update.
  91                 * Applies to all PIIX4 models.
  92                 */
  93
  94                /*
  95                 * BM-IDE
  96                 * ------
  97                 * Find the PIIX4 IDE Controller and get the Bus Master IDE
  98                 * Status register address.  We'll use this later to read
  99                 * each IDE controller's DMA status to make sure we catch all
 100                 * DMA activity.
 101                 */
 102                dev = pci_get_subsys(PCI_VENDOR_ID_INTEL,
 103                                     PCI_DEVICE_ID_INTEL_82371AB,
 104                                     PCI_ANY_ID, PCI_ANY_ID, NULL);
 105                if (dev) {
 106                        errata.piix4.bmisx = pci_resource_start(dev, 4);
 107                        pci_dev_put(dev);
 108                }
 109
 110                /*
 111                 * Type-F DMA
 112                 * ----------
 113                 * Find the PIIX4 ISA Controller and read the Motherboard
 114                 * DMA controller's status to see if Type-F (Fast) DMA mode
 115                 * is enabled (bit 7) on either channel.  Note that we'll
 116                 * disable C3 support if this is enabled, as some legacy
 117                 * devices won't operate well if fast DMA is disabled.
 118                 */
 119                dev = pci_get_subsys(PCI_VENDOR_ID_INTEL,
 120                                     PCI_DEVICE_ID_INTEL_82371AB_0,
 121                                     PCI_ANY_ID, PCI_ANY_ID, NULL);
 122                if (dev) {
 123                        pci_read_config_byte(dev, 0x76, &value1);
 124                        pci_read_config_byte(dev, 0x77, &value2);
 125                        if ((value1 & 0x80) || (value2 & 0x80))
 126                                errata.piix4.fdma = 1;
 127                        pci_dev_put(dev);
 128                }
 129
 130                break;
 131        }
 132
 133        if (errata.piix4.bmisx)
 134                ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 135                                  "Bus master activity detection (BM-IDE) erratum enabled\n"));
 136        if (errata.piix4.fdma)
 137                ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 138                                  "Type-F DMA livelock erratum (C3 disabled)\n"));
 139
 140        return 0;
 141}
 142
 143static int acpi_processor_errata(struct acpi_processor *pr)
 144{
 145        int result = 0;
 146        struct pci_dev *dev = NULL;
 147
 148
 149        if (!pr)
 150                return -EINVAL;
 151
 152        /*
 153         * PIIX4
 154         */
 155        dev = pci_get_subsys(PCI_VENDOR_ID_INTEL,
 156                             PCI_DEVICE_ID_INTEL_82371AB_3, PCI_ANY_ID,
 157                             PCI_ANY_ID, NULL);
 158        if (dev) {
 159                result = acpi_processor_errata_piix4(dev);
 160                pci_dev_put(dev);
 161        }
 162
 163        return result;
 164}
 165
 166/* --------------------------------------------------------------------------
 167                                Initialization
 168   -------------------------------------------------------------------------- */
 169
 170#ifdef CONFIG_ACPI_HOTPLUG_CPU
 171static int acpi_processor_hotadd_init(struct acpi_processor *pr)
 172{
 173        unsigned long long sta;
 174        acpi_status status;
 175        int ret;
 176
 177        status = acpi_evaluate_integer(pr->handle, "_STA", NULL, &sta);
 178        if (ACPI_FAILURE(status) || !(sta & ACPI_STA_DEVICE_PRESENT))
 179                return -ENODEV;
 180
 181        cpu_maps_update_begin();
 182        cpu_hotplug_begin();
 183
 184        ret = acpi_map_lsapic(pr->handle, &pr->id);
 185        if (ret)
 186                goto out;
 187
 188        ret = arch_register_cpu(pr->id);
 189        if (ret) {
 190                acpi_unmap_lsapic(pr->id);
 191                goto out;
 192        }
 193
 194        /*
 195         * CPU got hot-added, but cpu_data is not initialized yet.  Set a flag
 196         * to delay cpu_idle/throttling initialization and do it when the CPU
 197         * gets online for the first time.
 198         */
 199        pr_info("CPU%d has been hot-added\n", pr->id);
 200        pr->flags.need_hotplug_init = 1;
 201
 202out:
 203        cpu_hotplug_done();
 204        cpu_maps_update_done();
 205        return ret;
 206}
 207#else
 208static inline int acpi_processor_hotadd_init(struct acpi_processor *pr)
 209{
 210        return -ENODEV;
 211}
 212#endif /* CONFIG_ACPI_HOTPLUG_CPU */
 213
 214static int acpi_processor_get_info(struct acpi_device *device)
 215{
 216        union acpi_object object = { 0 };
 217        struct acpi_buffer buffer = { sizeof(union acpi_object), &object };
 218        struct acpi_processor *pr = acpi_driver_data(device);
 219        int cpu_index, device_declaration = 0;
 220        acpi_status status = AE_OK;
 221        static int cpu0_initialized;
 222
 223        if (num_online_cpus() > 1)
 224                errata.smp = TRUE;
 225
 226        acpi_processor_errata(pr);
 227
 228        /*
 229         * Check to see if we have bus mastering arbitration control.  This
 230         * is required for proper C3 usage (to maintain cache coherency).
 231         */
 232        if (acpi_gbl_FADT.pm2_control_block && acpi_gbl_FADT.pm2_control_length) {
 233                pr->flags.bm_control = 1;
 234                ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 235                                  "Bus mastering arbitration control present\n"));
 236        } else
 237                ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 238                                  "No bus mastering arbitration control\n"));
 239
 240        if (!strcmp(acpi_device_hid(device), ACPI_PROCESSOR_OBJECT_HID)) {
 241                /* Declared with "Processor" statement; match ProcessorID */
 242                status = acpi_evaluate_object(pr->handle, NULL, NULL, &buffer);
 243                if (ACPI_FAILURE(status)) {
 244                        dev_err(&device->dev,
 245                                "Failed to evaluate processor object (0x%x)\n",
 246                                status);
 247                        return -ENODEV;
 248                }
 249
 250                /*
 251                 * TBD: Synch processor ID (via LAPIC/LSAPIC structures) on SMP.
 252                 *      >>> 'acpi_get_processor_id(acpi_id, &id)' in
 253                 *      arch/xxx/acpi.c
 254                 */
 255                pr->acpi_id = object.processor.proc_id;
 256        } else {
 257                /*
 258                 * Declared with "Device" statement; match _UID.
 259                 * Note that we don't handle string _UIDs yet.
 260                 */
 261                unsigned long long value;
 262                status = acpi_evaluate_integer(pr->handle, METHOD_NAME__UID,
 263                                                NULL, &value);
 264                if (ACPI_FAILURE(status)) {
 265                        dev_err(&device->dev,
 266                                "Failed to evaluate processor _UID (0x%x)\n",
 267                                status);
 268                        return -ENODEV;
 269                }
 270                device_declaration = 1;
 271                pr->acpi_id = value;
 272        }
 273        cpu_index = acpi_get_cpuid(pr->handle, device_declaration, pr->acpi_id);
 274
 275        /* Handle UP system running SMP kernel, with no LAPIC in MADT */
 276        if (!cpu0_initialized && (cpu_index == -1) &&
 277            (num_online_cpus() == 1)) {
 278                cpu_index = 0;
 279        }
 280
 281        cpu0_initialized = 1;
 282
 283        pr->id = cpu_index;
 284
 285        /*
 286         *  Extra Processor objects may be enumerated on MP systems with
 287         *  less than the max # of CPUs. They should be ignored _iff
 288         *  they are physically not present.
 289         */
 290        if (pr->id == -1) {
 291                int ret = acpi_processor_hotadd_init(pr);
 292                if (ret)
 293                        return ret;
 294        }
 295        /*
 296         * On some boxes several processors use the same processor bus id.
 297         * But they are located in different scope. For example:
 298         * \_SB.SCK0.CPU0
 299         * \_SB.SCK1.CPU0
 300         * Rename the processor device bus id. And the new bus id will be
 301         * generated as the following format:
 302         * CPU+CPU ID.
 303         */
 304        sprintf(acpi_device_bid(device), "CPU%X", pr->id);
 305        ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Processor [%d:%d]\n", pr->id,
 306                          pr->acpi_id));
 307
 308        if (!object.processor.pblk_address)
 309                ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No PBLK (NULL address)\n"));
 310        else if (object.processor.pblk_length != 6)
 311                dev_err(&device->dev, "Invalid PBLK length [%d]\n",
 312                            object.processor.pblk_length);
 313        else {
 314                pr->throttling.address = object.processor.pblk_address;
 315                pr->throttling.duty_offset = acpi_gbl_FADT.duty_offset;
 316                pr->throttling.duty_width = acpi_gbl_FADT.duty_width;
 317
 318                pr->pblk = object.processor.pblk_address;
 319
 320                /*
 321                 * We don't care about error returns - we just try to mark
 322                 * these reserved so that nobody else is confused into thinking
 323                 * that this region might be unused..
 324                 *
 325                 * (In particular, allocating the IO range for Cardbus)
 326                 */
 327                request_region(pr->throttling.address, 6, "ACPI CPU throttle");
 328        }
 329
 330        /*
 331         * If ACPI describes a slot number for this CPU, we can use it to
 332         * ensure we get the right value in the "physical id" field
 333         * of /proc/cpuinfo
 334         */
 335        status = acpi_evaluate_object(pr->handle, "_SUN", NULL, &buffer);
 336        if (ACPI_SUCCESS(status))
 337                arch_fix_phys_package_id(pr->id, object.integer.value);
 338
 339        return 0;
 340}
 341
 342/*
 343 * Do not put anything in here which needs the core to be online.
 344 * For example MSR access or setting up things which check for cpuinfo_x86
 345 * (cpu_data(cpu)) values, like CPU feature flags, family, model, etc.
 346 * Such things have to be put in and set up by the processor driver's .probe().
 347 */
 348static DEFINE_PER_CPU(void *, processor_device_array);
 349
 350static int acpi_processor_add(struct acpi_device *device,
 351                                        const struct acpi_device_id *id)
 352{
 353        struct acpi_processor *pr;
 354        struct device *dev;
 355        int result = 0;
 356
 357        pr = kzalloc(sizeof(struct acpi_processor), GFP_KERNEL);
 358        if (!pr)
 359                return -ENOMEM;
 360
 361        if (!zalloc_cpumask_var(&pr->throttling.shared_cpu_map, GFP_KERNEL)) {
 362                result = -ENOMEM;
 363                goto err_free_pr;
 364        }
 365
 366        pr->handle = device->handle;
 367        strcpy(acpi_device_name(device), ACPI_PROCESSOR_DEVICE_NAME);
 368        strcpy(acpi_device_class(device), ACPI_PROCESSOR_CLASS);
 369        device->driver_data = pr;
 370
 371        result = acpi_processor_get_info(device);
 372        if (result) /* Processor is not physically present or unavailable */
 373                return 0;
 374
 375#ifdef CONFIG_SMP
 376        if (pr->id >= setup_max_cpus && pr->id != 0)
 377                return 0;
 378#endif
 379
 380        BUG_ON(pr->id >= nr_cpu_ids);
 381
 382        /*
 383         * Buggy BIOS check.
 384         * ACPI id of processors can be reported wrongly by the BIOS.
 385         * Don't trust it blindly
 386         */
 387        if (per_cpu(processor_device_array, pr->id) != NULL &&
 388            per_cpu(processor_device_array, pr->id) != device) {
 389                dev_warn(&device->dev,
 390                        "BIOS reported wrong ACPI id %d for the processor\n",
 391                        pr->id);
 392                /* Give up, but do not abort the namespace scan. */
 393                goto err;
 394        }
 395        /*
 396         * processor_device_array is not cleared on errors to allow buggy BIOS
 397         * checks.
 398         */
 399        per_cpu(processor_device_array, pr->id) = device;
 400        per_cpu(processors, pr->id) = pr;
 401
 402        dev = get_cpu_device(pr->id);
 403        if (!dev) {
 404                result = -ENODEV;
 405                goto err;
 406        }
 407
 408        result = acpi_bind_one(dev, pr->handle);
 409        if (result)
 410                goto err;
 411
 412        pr->dev = dev;
 413        dev->offline = pr->flags.need_hotplug_init;
 414
 415        /* Trigger the processor driver's .probe() if present. */
 416        if (device_attach(dev) >= 0)
 417                return 1;
 418
 419        dev_err(dev, "Processor driver could not be attached\n");
 420        acpi_unbind_one(dev);
 421
 422 err:
 423        free_cpumask_var(pr->throttling.shared_cpu_map);
 424        device->driver_data = NULL;
 425        per_cpu(processors, pr->id) = NULL;
 426 err_free_pr:
 427        kfree(pr);
 428        return result;
 429}
 430
 431#ifdef CONFIG_ACPI_HOTPLUG_CPU
 432/* --------------------------------------------------------------------------
 433                                    Removal
 434   -------------------------------------------------------------------------- */
 435
 436static void acpi_processor_remove(struct acpi_device *device)
 437{
 438        struct acpi_processor *pr;
 439
 440        if (!device || !acpi_driver_data(device))
 441                return;
 442
 443        pr = acpi_driver_data(device);
 444        if (pr->id >= nr_cpu_ids)
 445                goto out;
 446
 447        /*
 448         * The only reason why we ever get here is CPU hot-removal.  The CPU is
 449         * already offline and the ACPI device removal locking prevents it from
 450         * being put back online at this point.
 451         *
 452         * Unbind the driver from the processor device and detach it from the
 453         * ACPI companion object.
 454         */
 455        device_release_driver(pr->dev);
 456        acpi_unbind_one(pr->dev);
 457
 458        /* Clean up. */
 459        per_cpu(processor_device_array, pr->id) = NULL;
 460        per_cpu(processors, pr->id) = NULL;
 461
 462        cpu_maps_update_begin();
 463        cpu_hotplug_begin();
 464
 465        /* Remove the CPU. */
 466        arch_unregister_cpu(pr->id);
 467        acpi_unmap_lsapic(pr->id);
 468
 469        cpu_hotplug_done();
 470        cpu_maps_update_done();
 471
 472        try_offline_node(cpu_to_node(pr->id));
 473
 474 out:
 475        free_cpumask_var(pr->throttling.shared_cpu_map);
 476        kfree(pr);
 477}
 478#endif /* CONFIG_ACPI_HOTPLUG_CPU */
 479
 480/*
 481 * The following ACPI IDs are known to be suitable for representing as
 482 * processor devices.
 483 */
 484static const struct acpi_device_id processor_device_ids[] = {
 485
 486        { ACPI_PROCESSOR_OBJECT_HID, },
 487        { ACPI_PROCESSOR_DEVICE_HID, },
 488
 489        { }
 490};
 491
 492static struct acpi_scan_handler __refdata processor_handler = {
 493        .ids = processor_device_ids,
 494        .attach = acpi_processor_add,
 495#ifdef CONFIG_ACPI_HOTPLUG_CPU
 496        .detach = acpi_processor_remove,
 497#endif
 498        .hotplug = {
 499                .enabled = true,
 500        },
 501};
 502
 503void __init acpi_processor_init(void)
 504{
 505        acpi_scan_add_handler_with_hotplug(&processor_handler, "processor");
 506}
 507
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