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(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
 171 static 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
 202 out:
 203         cpu_hotplug_done();
 204         cpu_maps_update_done();
 205         return ret;
 206 }
 207 #else
 208 static inline int acpi_processor_hotadd_init(struct acpi_processor *pr)
 209 {
 210         return -ENODEV;
 211 }
 212 #endif /* CONFIG_ACPI_HOTPLUG_CPU */
 213
 214 static 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  */
 348 static DEFINE_PER_CPU(void *, processor_device_array);
 349
 350 static 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
 436 static 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  */
 484 static const struct acpi_device_id processor_device_ids[] = {
 485
 486         { ACPI_PROCESSOR_OBJECT_HID, },
 487         { ACPI_PROCESSOR_DEVICE_HID, },
 488
 489         { }
 490 };
 491
 492 static 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
 503 void __init acpi_processor_init(void)
 504 {
 505         acpi_scan_add_handler_with_hotplug(&processor_handler, "processor");
 506 }