kernel/drivers/acpi/acpi_processor.c

   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
  30 ACPI_MODULE_NAME("processor");
  31
  32 DEFINE_PER_CPU(struct acpi_processor *, processors);
  33 EXPORT_PER_CPU_SYMBOL(processors);
  34
  35 /* --------------------------------------------------------------------------
  36                                 Errata Handling
  37    -------------------------------------------------------------------------- */
  38
  39 struct acpi_processor_errata errata __read_mostly;
  40 EXPORT_SYMBOL_GPL(errata);
  41
  42 static 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
 143 static int acpi_processor_errata(void)
 144 {
 145         int result = 0;
 146         struct pci_dev *dev = NULL;
 147
 148         /*
 149          * PIIX4
 150          */
 151         dev = pci_get_subsys(PCI_VENDOR_ID_INTEL,
 152                              PCI_DEVICE_ID_INTEL_82371AB_3, PCI_ANY_ID,
 153                              PCI_ANY_ID, NULL);
 154         if (dev) {
 155                 result = acpi_processor_errata_piix4(dev);
 156                 pci_dev_put(dev);
 157         }
 158
 159         return result;
 160 }
 161
 162 /* --------------------------------------------------------------------------
 163                                 Initialization
 164    -------------------------------------------------------------------------- */
 165
 166 #ifdef CONFIG_ACPI_HOTPLUG_CPU
 167 int __weak acpi_map_cpu(acpi_handle handle,
 168                 phys_cpuid_t physid, int *pcpu)
 169 {
 170         return -ENODEV;
 171 }
 172
 173 int __weak acpi_unmap_cpu(int cpu)
 174 {
 175         return -ENODEV;
 176 }
 177
 178 int __weak arch_register_cpu(int cpu)
 179 {
 180         return -ENODEV;
 181 }
 182
 183 void __weak arch_unregister_cpu(int cpu) {}
 184
 185 static int acpi_processor_hotadd_init(struct acpi_processor *pr)
 186 {
 187         unsigned long long sta;
 188         acpi_status status;
 189         int ret;
 190
 191         if (invalid_phys_cpuid(pr->phys_id))
 192                 return -ENODEV;
 193
 194         status = acpi_evaluate_integer(pr->handle, "_STA", NULL, &sta);
 195         if (ACPI_FAILURE(status) || !(sta & ACPI_STA_DEVICE_PRESENT))
 196                 return -ENODEV;
 197
 198         cpu_maps_update_begin();
 199         cpu_hotplug_begin();
 200
 201         ret = acpi_map_cpu(pr->handle, pr->phys_id, &pr->id);
 202         if (ret)
 203                 goto out;
 204
 205         ret = arch_register_cpu(pr->id);
 206         if (ret) {
 207                 acpi_unmap_cpu(pr->id);
 208                 goto out;
 209         }
 210
 211         /*
 212          * CPU got hot-added, but cpu_data is not initialized yet.  Set a flag
 213          * to delay cpu_idle/throttling initialization and do it when the CPU
 214          * gets online for the first time.
 215          */
 216         pr_info("CPU%d has been hot-added\n", pr->id);
 217         pr->flags.need_hotplug_init = 1;
 218
 219 out:
 220         cpu_hotplug_done();
 221         cpu_maps_update_done();
 222         return ret;
 223 }
 224 #else
 225 static inline int acpi_processor_hotadd_init(struct acpi_processor *pr)
 226 {
 227         return -ENODEV;
 228 }
 229 #endif /* CONFIG_ACPI_HOTPLUG_CPU */
 230
 231 static int acpi_processor_get_info(struct acpi_device *device)
 232 {
 233         union acpi_object object = { 0 };
 234         struct acpi_buffer buffer = { sizeof(union acpi_object), &object };
 235         struct acpi_processor *pr = acpi_driver_data(device);
 236         int device_declaration = 0;
 237         acpi_status status = AE_OK;
 238         static int cpu0_initialized;
 239         unsigned long long value;
 240
 241         acpi_processor_errata();
 242
 243         /*
 244          * Check to see if we have bus mastering arbitration control.  This
 245          * is required for proper C3 usage (to maintain cache coherency).
 246          */
 247         if (acpi_gbl_FADT.pm2_control_block && acpi_gbl_FADT.pm2_control_length) {
 248                 pr->flags.bm_control = 1;
 249                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 250                                   "Bus mastering arbitration control present\n"));
 251         } else
 252                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 253                                   "No bus mastering arbitration control\n"));
 254
 255         if (!strcmp(acpi_device_hid(device), ACPI_PROCESSOR_OBJECT_HID)) {
 256                 /* Declared with "Processor" statement; match ProcessorID */
 257                 status = acpi_evaluate_object(pr->handle, NULL, NULL, &buffer);
 258                 if (ACPI_FAILURE(status)) {
 259                         dev_err(&device->dev,
 260                                 "Failed to evaluate processor object (0x%x)\n",
 261                                 status);
 262                         return -ENODEV;
 263                 }
 264
 265                 pr->acpi_id = object.processor.proc_id;
 266         } else {
 267                 /*
 268                  * Declared with "Device" statement; match _UID.
 269                  * Note that we don't handle string _UIDs yet.
 270                  */
 271                 status = acpi_evaluate_integer(pr->handle, METHOD_NAME__UID,
 272                                                 NULL, &value);
 273                 if (ACPI_FAILURE(status)) {
 274                         dev_err(&device->dev,
 275                                 "Failed to evaluate processor _UID (0x%x)\n",
 276                                 status);
 277                         return -ENODEV;
 278                 }
 279                 device_declaration = 1;
 280                 pr->acpi_id = value;
 281         }
 282
 283         pr->phys_id = acpi_get_phys_id(pr->handle, device_declaration,
 284                                         pr->acpi_id);
 285         if (invalid_phys_cpuid(pr->phys_id))
 286                 acpi_handle_debug(pr->handle, "failed to get CPU physical ID.\n");
 287
 288         pr->id = acpi_map_cpuid(pr->phys_id, pr->acpi_id);
 289         if (!cpu0_initialized && !acpi_has_cpu_in_madt()) {
 290                 cpu0_initialized = 1;
 291                 /*
 292                  * Handle UP system running SMP kernel, with no CPU
 293                  * entry in MADT
 294                  */
 295                 if (invalid_logical_cpuid(pr->id) && (num_online_cpus() == 1))
 296                         pr->id = 0;
 297         }
 298
 299         /*
 300          *  Extra Processor objects may be enumerated on MP systems with
 301          *  less than the max # of CPUs. They should be ignored _iff
 302          *  they are physically not present.
 303          */
 304         if (invalid_logical_cpuid(pr->id)) {
 305                 int ret = acpi_processor_hotadd_init(pr);
 306                 if (ret)
 307                         return ret;
 308         }
 309
 310         /*
 311          * On some boxes several processors use the same processor bus id.
 312          * But they are located in different scope. For example:
 313          * \_SB.SCK0.CPU0
 314          * \_SB.SCK1.CPU0
 315          * Rename the processor device bus id. And the new bus id will be
 316          * generated as the following format:
 317          * CPU+CPU ID.
 318          */
 319         sprintf(acpi_device_bid(device), "CPU%X", pr->id);
 320         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Processor [%d:%d]\n", pr->id,
 321                           pr->acpi_id));
 322
 323         if (!object.processor.pblk_address)
 324                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No PBLK (NULL address)\n"));
 325         else if (object.processor.pblk_length != 6)
 326                 dev_err(&device->dev, "Invalid PBLK length [%d]\n",
 327                             object.processor.pblk_length);
 328         else {
 329                 pr->throttling.address = object.processor.pblk_address;
 330                 pr->throttling.duty_offset = acpi_gbl_FADT.duty_offset;
 331                 pr->throttling.duty_width = acpi_gbl_FADT.duty_width;
 332
 333                 pr->pblk = object.processor.pblk_address;
 334
 335                 /*
 336                  * We don't care about error returns - we just try to mark
 337                  * these reserved so that nobody else is confused into thinking
 338                  * that this region might be unused..
 339                  *
 340                  * (In particular, allocating the IO range for Cardbus)
 341                  */
 342                 request_region(pr->throttling.address, 6, "ACPI CPU throttle");
 343         }
 344
 345         /*
 346          * If ACPI describes a slot number for this CPU, we can use it to
 347          * ensure we get the right value in the "physical id" field
 348          * of /proc/cpuinfo
 349          */
 350         status = acpi_evaluate_integer(pr->handle, "_SUN", NULL, &value);
 351         if (ACPI_SUCCESS(status))
 352                 arch_fix_phys_package_id(pr->id, value);
 353
 354         return 0;
 355 }
 356
 357 /*
 358  * Do not put anything in here which needs the core to be online.
 359  * For example MSR access or setting up things which check for cpuinfo_x86
 360  * (cpu_data(cpu)) values, like CPU feature flags, family, model, etc.
 361  * Such things have to be put in and set up by the processor driver's .probe().
 362  */
 363 static DEFINE_PER_CPU(void *, processor_device_array);
 364
 365 static int acpi_processor_add(struct acpi_device *device,
 366                                         const struct acpi_device_id *id)
 367 {
 368         struct acpi_processor *pr;
 369         struct device *dev;
 370         int result = 0;
 371
 372         pr = kzalloc(sizeof(struct acpi_processor), GFP_KERNEL);
 373         if (!pr)
 374                 return -ENOMEM;
 375
 376         if (!zalloc_cpumask_var(&pr->throttling.shared_cpu_map, GFP_KERNEL)) {
 377                 result = -ENOMEM;
 378                 goto err_free_pr;
 379         }
 380
 381         pr->handle = device->handle;
 382         strcpy(acpi_device_name(device), ACPI_PROCESSOR_DEVICE_NAME);
 383         strcpy(acpi_device_class(device), ACPI_PROCESSOR_CLASS);
 384         device->driver_data = pr;
 385
 386         result = acpi_processor_get_info(device);
 387         if (result) /* Processor is not physically present or unavailable */
 388                 return 0;
 389
 390 #ifdef CONFIG_SMP
 391         if (pr->id >= setup_max_cpus && pr->id != 0)
 392                 return 0;
 393 #endif
 394
 395         BUG_ON(pr->id >= nr_cpu_ids);
 396
 397         /*
 398          * Buggy BIOS check.
 399          * ACPI id of processors can be reported wrongly by the BIOS.
 400          * Don't trust it blindly
 401          */
 402         if (per_cpu(processor_device_array, pr->id) != NULL &&
 403             per_cpu(processor_device_array, pr->id) != device) {
 404                 dev_warn(&device->dev,
 405                         "BIOS reported wrong ACPI id %d for the processor\n",
 406                         pr->id);
 407                 /* Give up, but do not abort the namespace scan. */
 408                 goto err;
 409         }
 410         /*
 411          * processor_device_array is not cleared on errors to allow buggy BIOS
 412          * checks.
 413          */
 414         per_cpu(processor_device_array, pr->id) = device;
 415         per_cpu(processors, pr->id) = pr;
 416
 417         dev = get_cpu_device(pr->id);
 418         if (!dev) {
 419                 result = -ENODEV;
 420                 goto err;
 421         }
 422
 423         result = acpi_bind_one(dev, device);
 424         if (result)
 425                 goto err;
 426
 427         pr->dev = dev;
 428
 429         /* Trigger the processor driver's .probe() if present. */
 430         if (device_attach(dev) >= 0)
 431                 return 1;
 432
 433         dev_err(dev, "Processor driver could not be attached\n");
 434         acpi_unbind_one(dev);
 435
 436  err:
 437         free_cpumask_var(pr->throttling.shared_cpu_map);
 438         device->driver_data = NULL;
 439         per_cpu(processors, pr->id) = NULL;
 440  err_free_pr:
 441         kfree(pr);
 442         return result;
 443 }
 444
 445 #ifdef CONFIG_ACPI_HOTPLUG_CPU
 446 /* --------------------------------------------------------------------------
 447                                     Removal
 448    -------------------------------------------------------------------------- */
 449
 450 static void acpi_processor_remove(struct acpi_device *device)
 451 {
 452         struct acpi_processor *pr;
 453
 454         if (!device || !acpi_driver_data(device))
 455                 return;
 456
 457         pr = acpi_driver_data(device);
 458         if (pr->id >= nr_cpu_ids)
 459                 goto out;
 460
 461         /*
 462          * The only reason why we ever get here is CPU hot-removal.  The CPU is
 463          * already offline and the ACPI device removal locking prevents it from
 464          * being put back online at this point.
 465          *
 466          * Unbind the driver from the processor device and detach it from the
 467          * ACPI companion object.
 468          */
 469         device_release_driver(pr->dev);
 470         acpi_unbind_one(pr->dev);
 471
 472         /* Clean up. */
 473         per_cpu(processor_device_array, pr->id) = NULL;
 474         per_cpu(processors, pr->id) = NULL;
 475
 476         cpu_maps_update_begin();
 477         cpu_hotplug_begin();
 478
 479         /* Remove the CPU. */
 480         arch_unregister_cpu(pr->id);
 481         acpi_unmap_cpu(pr->id);
 482
 483         cpu_hotplug_done();
 484         cpu_maps_update_done();
 485
 486         try_offline_node(cpu_to_node(pr->id));
 487
 488  out:
 489         free_cpumask_var(pr->throttling.shared_cpu_map);
 490         kfree(pr);
 491 }
 492 #endif /* CONFIG_ACPI_HOTPLUG_CPU */
 493
 494 /*
 495  * The following ACPI IDs are known to be suitable for representing as
 496  * processor devices.
 497  */
 498 static const struct acpi_device_id processor_device_ids[] = {
 499
 500         { ACPI_PROCESSOR_OBJECT_HID, },
 501         { ACPI_PROCESSOR_DEVICE_HID, },
 502
 503         { }
 504 };
 505
 506 static struct acpi_scan_handler processor_handler = {
 507         .ids = processor_device_ids,
 508         .attach = acpi_processor_add,
 509 #ifdef CONFIG_ACPI_HOTPLUG_CPU
 510         .detach = acpi_processor_remove,
 511 #endif
 512         .hotplug = {
 513                 .enabled = true,
 514         },
 515 };
 516
 517 void __init acpi_processor_init(void)
 518 {
 519         acpi_scan_add_handler_with_hotplug(&processor_handler, "processor");
 520 }