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