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