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->apic_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_lsapic(pr->handle, pr->apic_id, &pr->id); 184 if (ret) 185 goto out; 186 187 ret = arch_register_cpu(pr->id); 188 if (ret) { 189 acpi_unmap_lsapic(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 apic_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 apic_id = acpi_get_apicid(pr->handle, device_declaration, pr->acpi_id); 266 if (apic_id < 0) 267 acpi_handle_debug(pr->handle, "failed to get CPU APIC ID.\n"); 268 pr->apic_id = apic_id; 269 270 cpu_index = acpi_map_cpuid(pr->apic_id, pr->acpi_id); 271 if (!cpu0_initialized && !acpi_lapic) { 272 cpu0_initialized = 1; 273 /* Handle UP system running SMP kernel, with no LAPIC in MADT */ 274 if ((cpu_index == -1) && (num_online_cpus() == 1)) 275 cpu_index = 0; 276 } 277 pr->id = cpu_index; 278 279 /* 280 * Extra Processor objects may be enumerated on MP systems with 281 * less than the max # of CPUs. They should be ignored _iff 282 * they are physically not present. 283 */ 284 if (pr->id == -1) { 285 int ret = acpi_processor_hotadd_init(pr); 286 if (ret) 287 return ret; 288 } 289 290 /* 291 * On some boxes several processors use the same processor bus id. 292 * But they are located in different scope. For example: 293 * \_SB.SCK0.CPU0 294 * \_SB.SCK1.CPU0 295 * Rename the processor device bus id. And the new bus id will be 296 * generated as the following format: 297 * CPU+CPU ID. 298 */ 299 sprintf(acpi_device_bid(device), "CPU%X", pr->id); 300 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Processor [%d:%d]\n", pr->id, 301 pr->acpi_id)); 302 303 if (!object.processor.pblk_address) 304 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No PBLK (NULL address)\n")); 305 else if (object.processor.pblk_length != 6) 306 dev_err(&device->dev, "Invalid PBLK length [%d]\n", 307 object.processor.pblk_length); 308 else { 309 pr->throttling.address = object.processor.pblk_address; 310 pr->throttling.duty_offset = acpi_gbl_FADT.duty_offset; 311 pr->throttling.duty_width = acpi_gbl_FADT.duty_width; 312 313 pr->pblk = object.processor.pblk_address; 314 315 /* 316 * We don't care about error returns - we just try to mark 317 * these reserved so that nobody else is confused into thinking 318 * that this region might be unused.. 319 * 320 * (In particular, allocating the IO range for Cardbus) 321 */ 322 request_region(pr->throttling.address, 6, "ACPI CPU throttle"); 323 } 324 325 /* 326 * If ACPI describes a slot number for this CPU, we can use it to 327 * ensure we get the right value in the "physical id" field 328 * of /proc/cpuinfo 329 */ 330 status = acpi_evaluate_integer(pr->handle, "_SUN", NULL, &value); 331 if (ACPI_SUCCESS(status)) 332 arch_fix_phys_package_id(pr->id, value); 333 334 return 0; 335 } 336 337 /* 338 * Do not put anything in here which needs the core to be online. 339 * For example MSR access or setting up things which check for cpuinfo_x86 340 * (cpu_data(cpu)) values, like CPU feature flags, family, model, etc. 341 * Such things have to be put in and set up by the processor driver's .probe(). 342 */ 343 static DEFINE_PER_CPU(void *, processor_device_array); 344 345 static int acpi_processor_add(struct acpi_device *device, 346 const struct acpi_device_id *id) 347 { 348 struct acpi_processor *pr; 349 struct device *dev; 350 int result = 0; 351 352 pr = kzalloc(sizeof(struct acpi_processor), GFP_KERNEL); 353 if (!pr) 354 return -ENOMEM; 355 356 if (!zalloc_cpumask_var(&pr->throttling.shared_cpu_map, GFP_KERNEL)) { 357 result = -ENOMEM; 358 goto err_free_pr; 359 } 360 361 pr->handle = device->handle; 362 strcpy(acpi_device_name(device), ACPI_PROCESSOR_DEVICE_NAME); 363 strcpy(acpi_device_class(device), ACPI_PROCESSOR_CLASS); 364 device->driver_data = pr; 365 366 result = acpi_processor_get_info(device); 367 if (result) /* Processor is not physically present or unavailable */ 368 return 0; 369 370 #ifdef CONFIG_SMP 371 if (pr->id >= setup_max_cpus && pr->id != 0) 372 return 0; 373 #endif 374 375 BUG_ON(pr->id >= nr_cpu_ids); 376 377 /* 378 * Buggy BIOS check. 379 * ACPI id of processors can be reported wrongly by the BIOS. 380 * Don't trust it blindly 381 */ 382 if (per_cpu(processor_device_array, pr->id) != NULL && 383 per_cpu(processor_device_array, pr->id) != device) { 384 dev_warn(&device->dev, 385 "BIOS reported wrong ACPI id %d for the processor\n", 386 pr->id); 387 /* Give up, but do not abort the namespace scan. */ 388 goto err; 389 } 390 /* 391 * processor_device_array is not cleared on errors to allow buggy BIOS 392 * checks. 393 */ 394 per_cpu(processor_device_array, pr->id) = device; 395 per_cpu(processors, pr->id) = pr; 396 397 dev = get_cpu_device(pr->id); 398 if (!dev) { 399 result = -ENODEV; 400 goto err; 401 } 402 403 result = acpi_bind_one(dev, device); 404 if (result) 405 goto err; 406 407 pr->dev = dev; 408 409 /* Trigger the processor driver's .probe() if present. */ 410 if (device_attach(dev) >= 0) 411 return 1; 412 413 dev_err(dev, "Processor driver could not be attached\n"); 414 acpi_unbind_one(dev); 415 416 err: 417 free_cpumask_var(pr->throttling.shared_cpu_map); 418 device->driver_data = NULL; 419 per_cpu(processors, pr->id) = NULL; 420 err_free_pr: 421 kfree(pr); 422 return result; 423 } 424 425 #ifdef CONFIG_ACPI_HOTPLUG_CPU 426 /* -------------------------------------------------------------------------- 427 Removal 428 -------------------------------------------------------------------------- */ 429 430 static void acpi_processor_remove(struct acpi_device *device) 431 { 432 struct acpi_processor *pr; 433 434 if (!device || !acpi_driver_data(device)) 435 return; 436 437 pr = acpi_driver_data(device); 438 if (pr->id >= nr_cpu_ids) 439 goto out; 440 441 /* 442 * The only reason why we ever get here is CPU hot-removal. The CPU is 443 * already offline and the ACPI device removal locking prevents it from 444 * being put back online at this point. 445 * 446 * Unbind the driver from the processor device and detach it from the 447 * ACPI companion object. 448 */ 449 device_release_driver(pr->dev); 450 acpi_unbind_one(pr->dev); 451 452 /* Clean up. */ 453 per_cpu(processor_device_array, pr->id) = NULL; 454 per_cpu(processors, pr->id) = NULL; 455 456 cpu_maps_update_begin(); 457 cpu_hotplug_begin(); 458 459 /* Remove the CPU. */ 460 arch_unregister_cpu(pr->id); 461 acpi_unmap_lsapic(pr->id); 462 463 cpu_hotplug_done(); 464 cpu_maps_update_done(); 465 466 try_offline_node(cpu_to_node(pr->id)); 467 468 out: 469 free_cpumask_var(pr->throttling.shared_cpu_map); 470 kfree(pr); 471 } 472 #endif /* CONFIG_ACPI_HOTPLUG_CPU */ 473 474 /* 475 * The following ACPI IDs are known to be suitable for representing as 476 * processor devices. 477 */ 478 static const struct acpi_device_id processor_device_ids[] = { 479 480 { ACPI_PROCESSOR_OBJECT_HID, }, 481 { ACPI_PROCESSOR_DEVICE_HID, }, 482 483 { } 484 }; 485 486 static struct acpi_scan_handler __refdata processor_handler = { 487 .ids = processor_device_ids, 488 .attach = acpi_processor_add, 489 #ifdef CONFIG_ACPI_HOTPLUG_CPU 490 .detach = acpi_processor_remove, 491 #endif 492 .hotplug = { 493 .enabled = true, 494 }, 495 }; 496 497 void __init acpi_processor_init(void) 498 { 499 acpi_scan_add_handler_with_hotplug(&processor_handler, "processor"); 500 } 501