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