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