xref: /openbmc/linux/drivers/acpi/acpi_processor.c (revision a2977c0c)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * acpi_processor.c - ACPI processor enumeration support
4  *
5  * Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
6  * Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
7  * Copyright (C) 2004       Dominik Brodowski <linux@brodo.de>
8  * Copyright (C) 2004  Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
9  * Copyright (C) 2013, Intel Corporation
10  *                     Rafael J. Wysocki <rafael.j.wysocki@intel.com>
11  */
12 #define pr_fmt(fmt) "ACPI: " fmt
13 
14 #include <linux/acpi.h>
15 #include <linux/cpu.h>
16 #include <linux/device.h>
17 #include <linux/dmi.h>
18 #include <linux/kernel.h>
19 #include <linux/module.h>
20 #include <linux/pci.h>
21 #include <linux/platform_device.h>
22 
23 #include <acpi/processor.h>
24 
25 #include <asm/cpu.h>
26 
27 #include <xen/xen.h>
28 
29 #include "internal.h"
30 
31 DEFINE_PER_CPU(struct acpi_processor *, processors);
32 EXPORT_PER_CPU_SYMBOL(processors);
33 
34 /* Errata Handling */
35 struct acpi_processor_errata errata __read_mostly;
36 EXPORT_SYMBOL_GPL(errata);
37 
38 static int acpi_processor_errata_piix4(struct pci_dev *dev)
39 {
40 	u8 value1 = 0;
41 	u8 value2 = 0;
42 
43 
44 	if (!dev)
45 		return -EINVAL;
46 
47 	/*
48 	 * Note that 'dev' references the PIIX4 ACPI Controller.
49 	 */
50 
51 	switch (dev->revision) {
52 	case 0:
53 		dev_dbg(&dev->dev, "Found PIIX4 A-step\n");
54 		break;
55 	case 1:
56 		dev_dbg(&dev->dev, "Found PIIX4 B-step\n");
57 		break;
58 	case 2:
59 		dev_dbg(&dev->dev, "Found PIIX4E\n");
60 		break;
61 	case 3:
62 		dev_dbg(&dev->dev, "Found PIIX4M\n");
63 		break;
64 	default:
65 		dev_dbg(&dev->dev, "Found unknown PIIX4\n");
66 		break;
67 	}
68 
69 	switch (dev->revision) {
70 
71 	case 0:		/* PIIX4 A-step */
72 	case 1:		/* PIIX4 B-step */
73 		/*
74 		 * See specification changes #13 ("Manual Throttle Duty Cycle")
75 		 * and #14 ("Enabling and Disabling Manual Throttle"), plus
76 		 * erratum #5 ("STPCLK# Deassertion Time") from the January
77 		 * 2002 PIIX4 specification update.  Applies to only older
78 		 * PIIX4 models.
79 		 */
80 		errata.piix4.throttle = 1;
81 		fallthrough;
82 
83 	case 2:		/* PIIX4E */
84 	case 3:		/* PIIX4M */
85 		/*
86 		 * See erratum #18 ("C3 Power State/BMIDE and Type-F DMA
87 		 * Livelock") from the January 2002 PIIX4 specification update.
88 		 * Applies to all PIIX4 models.
89 		 */
90 
91 		/*
92 		 * BM-IDE
93 		 * ------
94 		 * Find the PIIX4 IDE Controller and get the Bus Master IDE
95 		 * Status register address.  We'll use this later to read
96 		 * each IDE controller's DMA status to make sure we catch all
97 		 * DMA activity.
98 		 */
99 		dev = pci_get_subsys(PCI_VENDOR_ID_INTEL,
100 				     PCI_DEVICE_ID_INTEL_82371AB,
101 				     PCI_ANY_ID, PCI_ANY_ID, NULL);
102 		if (dev) {
103 			errata.piix4.bmisx = pci_resource_start(dev, 4);
104 			pci_dev_put(dev);
105 		}
106 
107 		/*
108 		 * Type-F DMA
109 		 * ----------
110 		 * Find the PIIX4 ISA Controller and read the Motherboard
111 		 * DMA controller's status to see if Type-F (Fast) DMA mode
112 		 * is enabled (bit 7) on either channel.  Note that we'll
113 		 * disable C3 support if this is enabled, as some legacy
114 		 * devices won't operate well if fast DMA is disabled.
115 		 */
116 		dev = pci_get_subsys(PCI_VENDOR_ID_INTEL,
117 				     PCI_DEVICE_ID_INTEL_82371AB_0,
118 				     PCI_ANY_ID, PCI_ANY_ID, NULL);
119 		if (dev) {
120 			pci_read_config_byte(dev, 0x76, &value1);
121 			pci_read_config_byte(dev, 0x77, &value2);
122 			if ((value1 & 0x80) || (value2 & 0x80))
123 				errata.piix4.fdma = 1;
124 			pci_dev_put(dev);
125 		}
126 
127 		break;
128 	}
129 
130 	if (errata.piix4.bmisx)
131 		dev_dbg(&dev->dev, "Bus master activity detection (BM-IDE) erratum enabled\n");
132 	if (errata.piix4.fdma)
133 		dev_dbg(&dev->dev, "Type-F DMA livelock erratum (C3 disabled)\n");
134 
135 	return 0;
136 }
137 
138 static int acpi_processor_errata(void)
139 {
140 	int result = 0;
141 	struct pci_dev *dev = NULL;
142 
143 	/*
144 	 * PIIX4
145 	 */
146 	dev = pci_get_subsys(PCI_VENDOR_ID_INTEL,
147 			     PCI_DEVICE_ID_INTEL_82371AB_3, PCI_ANY_ID,
148 			     PCI_ANY_ID, NULL);
149 	if (dev) {
150 		result = acpi_processor_errata_piix4(dev);
151 		pci_dev_put(dev);
152 	}
153 
154 	return result;
155 }
156 
157 /* Create a platform device to represent a CPU frequency control mechanism. */
158 static void cpufreq_add_device(const char *name)
159 {
160 	struct platform_device *pdev;
161 
162 	pdev = platform_device_register_simple(name, PLATFORM_DEVID_NONE, NULL, 0);
163 	if (IS_ERR(pdev))
164 		pr_info("%s device creation failed: %ld\n", name, PTR_ERR(pdev));
165 }
166 
167 #ifdef CONFIG_X86
168 /* Check presence of Processor Clocking Control by searching for \_SB.PCCH. */
169 static void __init acpi_pcc_cpufreq_init(void)
170 {
171 	acpi_status status;
172 	acpi_handle handle;
173 
174 	status = acpi_get_handle(NULL, "\\_SB", &handle);
175 	if (ACPI_FAILURE(status))
176 		return;
177 
178 	if (acpi_has_method(handle, "PCCH"))
179 		cpufreq_add_device("pcc-cpufreq");
180 }
181 #else
182 static void __init acpi_pcc_cpufreq_init(void) {}
183 #endif /* CONFIG_X86 */
184 
185 /* Initialization */
186 #ifdef CONFIG_ACPI_HOTPLUG_CPU
187 int __weak acpi_map_cpu(acpi_handle handle,
188 		phys_cpuid_t physid, u32 acpi_id, int *pcpu)
189 {
190 	return -ENODEV;
191 }
192 
193 int __weak acpi_unmap_cpu(int cpu)
194 {
195 	return -ENODEV;
196 }
197 
198 int __weak arch_register_cpu(int cpu)
199 {
200 	return -ENODEV;
201 }
202 
203 void __weak arch_unregister_cpu(int cpu) {}
204 
205 static int acpi_processor_hotadd_init(struct acpi_processor *pr)
206 {
207 	unsigned long long sta;
208 	acpi_status status;
209 	int ret;
210 
211 	if (invalid_phys_cpuid(pr->phys_id))
212 		return -ENODEV;
213 
214 	status = acpi_evaluate_integer(pr->handle, "_STA", NULL, &sta);
215 	if (ACPI_FAILURE(status) || !(sta & ACPI_STA_DEVICE_PRESENT))
216 		return -ENODEV;
217 
218 	cpu_maps_update_begin();
219 	cpus_write_lock();
220 
221 	ret = acpi_map_cpu(pr->handle, pr->phys_id, pr->acpi_id, &pr->id);
222 	if (ret)
223 		goto out;
224 
225 	ret = arch_register_cpu(pr->id);
226 	if (ret) {
227 		acpi_unmap_cpu(pr->id);
228 		goto out;
229 	}
230 
231 	/*
232 	 * CPU got hot-added, but cpu_data is not initialized yet.  Set a flag
233 	 * to delay cpu_idle/throttling initialization and do it when the CPU
234 	 * gets online for the first time.
235 	 */
236 	pr_info("CPU%d has been hot-added\n", pr->id);
237 	pr->flags.need_hotplug_init = 1;
238 
239 out:
240 	cpus_write_unlock();
241 	cpu_maps_update_done();
242 	return ret;
243 }
244 #else
245 static inline int acpi_processor_hotadd_init(struct acpi_processor *pr)
246 {
247 	return -ENODEV;
248 }
249 #endif /* CONFIG_ACPI_HOTPLUG_CPU */
250 
251 static int acpi_processor_get_info(struct acpi_device *device)
252 {
253 	union acpi_object object = { 0 };
254 	struct acpi_buffer buffer = { sizeof(union acpi_object), &object };
255 	struct acpi_processor *pr = acpi_driver_data(device);
256 	int device_declaration = 0;
257 	acpi_status status = AE_OK;
258 	static int cpu0_initialized;
259 	unsigned long long value;
260 
261 	acpi_processor_errata();
262 
263 	/*
264 	 * Check to see if we have bus mastering arbitration control.  This
265 	 * is required for proper C3 usage (to maintain cache coherency).
266 	 */
267 	if (acpi_gbl_FADT.pm2_control_block && acpi_gbl_FADT.pm2_control_length) {
268 		pr->flags.bm_control = 1;
269 		dev_dbg(&device->dev, "Bus mastering arbitration control present\n");
270 	} else
271 		dev_dbg(&device->dev, "No bus mastering arbitration control\n");
272 
273 	if (!strcmp(acpi_device_hid(device), ACPI_PROCESSOR_OBJECT_HID)) {
274 		/* Declared with "Processor" statement; match ProcessorID */
275 		status = acpi_evaluate_object(pr->handle, NULL, NULL, &buffer);
276 		if (ACPI_FAILURE(status)) {
277 			dev_err(&device->dev,
278 				"Failed to evaluate processor object (0x%x)\n",
279 				status);
280 			return -ENODEV;
281 		}
282 
283 		pr->acpi_id = object.processor.proc_id;
284 	} else {
285 		/*
286 		 * Declared with "Device" statement; match _UID.
287 		 */
288 		status = acpi_evaluate_integer(pr->handle, METHOD_NAME__UID,
289 						NULL, &value);
290 		if (ACPI_FAILURE(status)) {
291 			dev_err(&device->dev,
292 				"Failed to evaluate processor _UID (0x%x)\n",
293 				status);
294 			return -ENODEV;
295 		}
296 		device_declaration = 1;
297 		pr->acpi_id = value;
298 	}
299 
300 	if (acpi_duplicate_processor_id(pr->acpi_id)) {
301 		if (pr->acpi_id == 0xff)
302 			dev_info_once(&device->dev,
303 				"Entry not well-defined, consider updating BIOS\n");
304 		else
305 			dev_err(&device->dev,
306 				"Failed to get unique processor _UID (0x%x)\n",
307 				pr->acpi_id);
308 		return -ENODEV;
309 	}
310 
311 	pr->phys_id = acpi_get_phys_id(pr->handle, device_declaration,
312 					pr->acpi_id);
313 	if (invalid_phys_cpuid(pr->phys_id))
314 		dev_dbg(&device->dev, "Failed to get CPU physical ID.\n");
315 
316 	pr->id = acpi_map_cpuid(pr->phys_id, pr->acpi_id);
317 	if (!cpu0_initialized) {
318 		cpu0_initialized = 1;
319 		/*
320 		 * Handle UP system running SMP kernel, with no CPU
321 		 * entry in MADT
322 		 */
323 		if (!acpi_has_cpu_in_madt() && invalid_logical_cpuid(pr->id) &&
324 		    (num_online_cpus() == 1))
325 			pr->id = 0;
326 		/*
327 		 * Check availability of Processor Performance Control by
328 		 * looking at the presence of the _PCT object under the first
329 		 * processor definition.
330 		 */
331 		if (acpi_has_method(pr->handle, "_PCT"))
332 			cpufreq_add_device("acpi-cpufreq");
333 	}
334 
335 	/*
336 	 *  Extra Processor objects may be enumerated on MP systems with
337 	 *  less than the max # of CPUs. They should be ignored _iff
338 	 *  they are physically not present.
339 	 *
340 	 *  NOTE: Even if the processor has a cpuid, it may not be present
341 	 *  because cpuid <-> apicid mapping is persistent now.
342 	 */
343 	if (invalid_logical_cpuid(pr->id) || !cpu_present(pr->id)) {
344 		int ret = acpi_processor_hotadd_init(pr);
345 
346 		if (ret)
347 			return ret;
348 	}
349 
350 	/*
351 	 * On some boxes several processors use the same processor bus id.
352 	 * But they are located in different scope. For example:
353 	 * \_SB.SCK0.CPU0
354 	 * \_SB.SCK1.CPU0
355 	 * Rename the processor device bus id. And the new bus id will be
356 	 * generated as the following format:
357 	 * CPU+CPU ID.
358 	 */
359 	sprintf(acpi_device_bid(device), "CPU%X", pr->id);
360 	dev_dbg(&device->dev, "Processor [%d:%d]\n", pr->id, pr->acpi_id);
361 
362 	if (!object.processor.pblk_address)
363 		dev_dbg(&device->dev, "No PBLK (NULL address)\n");
364 	else if (object.processor.pblk_length != 6)
365 		dev_err(&device->dev, "Invalid PBLK length [%d]\n",
366 			    object.processor.pblk_length);
367 	else {
368 		pr->throttling.address = object.processor.pblk_address;
369 		pr->throttling.duty_offset = acpi_gbl_FADT.duty_offset;
370 		pr->throttling.duty_width = acpi_gbl_FADT.duty_width;
371 
372 		pr->pblk = object.processor.pblk_address;
373 	}
374 
375 	/*
376 	 * If ACPI describes a slot number for this CPU, we can use it to
377 	 * ensure we get the right value in the "physical id" field
378 	 * of /proc/cpuinfo
379 	 */
380 	status = acpi_evaluate_integer(pr->handle, "_SUN", NULL, &value);
381 	if (ACPI_SUCCESS(status))
382 		arch_fix_phys_package_id(pr->id, value);
383 
384 	return 0;
385 }
386 
387 /*
388  * Do not put anything in here which needs the core to be online.
389  * For example MSR access or setting up things which check for cpuinfo_x86
390  * (cpu_data(cpu)) values, like CPU feature flags, family, model, etc.
391  * Such things have to be put in and set up by the processor driver's .probe().
392  */
393 static DEFINE_PER_CPU(void *, processor_device_array);
394 
395 static int acpi_processor_add(struct acpi_device *device,
396 					const struct acpi_device_id *id)
397 {
398 	struct acpi_processor *pr;
399 	struct device *dev;
400 	int result = 0;
401 
402 	pr = kzalloc(sizeof(struct acpi_processor), GFP_KERNEL);
403 	if (!pr)
404 		return -ENOMEM;
405 
406 	if (!zalloc_cpumask_var(&pr->throttling.shared_cpu_map, GFP_KERNEL)) {
407 		result = -ENOMEM;
408 		goto err_free_pr;
409 	}
410 
411 	pr->handle = device->handle;
412 	strcpy(acpi_device_name(device), ACPI_PROCESSOR_DEVICE_NAME);
413 	strcpy(acpi_device_class(device), ACPI_PROCESSOR_CLASS);
414 	device->driver_data = pr;
415 
416 	result = acpi_processor_get_info(device);
417 	if (result) /* Processor is not physically present or unavailable */
418 		goto err_clear_driver_data;
419 
420 	BUG_ON(pr->id >= nr_cpu_ids);
421 
422 	/*
423 	 * Buggy BIOS check.
424 	 * ACPI id of processors can be reported wrongly by the BIOS.
425 	 * Don't trust it blindly
426 	 */
427 	if (per_cpu(processor_device_array, pr->id) != NULL &&
428 	    per_cpu(processor_device_array, pr->id) != device) {
429 		dev_warn(&device->dev,
430 			"BIOS reported wrong ACPI id %d for the processor\n",
431 			pr->id);
432 		/* Give up, but do not abort the namespace scan. */
433 		goto err_clear_driver_data;
434 	}
435 	/*
436 	 * processor_device_array is not cleared on errors to allow buggy BIOS
437 	 * checks.
438 	 */
439 	per_cpu(processor_device_array, pr->id) = device;
440 	per_cpu(processors, pr->id) = pr;
441 
442 	dev = get_cpu_device(pr->id);
443 	if (!dev) {
444 		result = -ENODEV;
445 		goto err_clear_per_cpu;
446 	}
447 
448 	result = acpi_bind_one(dev, device);
449 	if (result)
450 		goto err_clear_per_cpu;
451 
452 	pr->dev = dev;
453 
454 	/* Trigger the processor driver's .probe() if present. */
455 	if (device_attach(dev) >= 0)
456 		return 1;
457 
458 	dev_err(dev, "Processor driver could not be attached\n");
459 	acpi_unbind_one(dev);
460 
461  err_clear_per_cpu:
462 	per_cpu(processors, pr->id) = NULL;
463  err_clear_driver_data:
464 	device->driver_data = NULL;
465 	free_cpumask_var(pr->throttling.shared_cpu_map);
466  err_free_pr:
467 	kfree(pr);
468 	return result;
469 }
470 
471 #ifdef CONFIG_ACPI_HOTPLUG_CPU
472 /* Removal */
473 static void acpi_processor_remove(struct acpi_device *device)
474 {
475 	struct acpi_processor *pr;
476 
477 	if (!device || !acpi_driver_data(device))
478 		return;
479 
480 	pr = acpi_driver_data(device);
481 	if (pr->id >= nr_cpu_ids)
482 		goto out;
483 
484 	/*
485 	 * The only reason why we ever get here is CPU hot-removal.  The CPU is
486 	 * already offline and the ACPI device removal locking prevents it from
487 	 * being put back online at this point.
488 	 *
489 	 * Unbind the driver from the processor device and detach it from the
490 	 * ACPI companion object.
491 	 */
492 	device_release_driver(pr->dev);
493 	acpi_unbind_one(pr->dev);
494 
495 	/* Clean up. */
496 	per_cpu(processor_device_array, pr->id) = NULL;
497 	per_cpu(processors, pr->id) = NULL;
498 
499 	cpu_maps_update_begin();
500 	cpus_write_lock();
501 
502 	/* Remove the CPU. */
503 	arch_unregister_cpu(pr->id);
504 	acpi_unmap_cpu(pr->id);
505 
506 	cpus_write_unlock();
507 	cpu_maps_update_done();
508 
509 	try_offline_node(cpu_to_node(pr->id));
510 
511  out:
512 	free_cpumask_var(pr->throttling.shared_cpu_map);
513 	kfree(pr);
514 }
515 #endif /* CONFIG_ACPI_HOTPLUG_CPU */
516 
517 #ifdef CONFIG_ARCH_MIGHT_HAVE_ACPI_PDC
518 bool __init processor_physically_present(acpi_handle handle)
519 {
520 	int cpuid, type;
521 	u32 acpi_id;
522 	acpi_status status;
523 	acpi_object_type acpi_type;
524 	unsigned long long tmp;
525 	union acpi_object object = {};
526 	struct acpi_buffer buffer = { sizeof(union acpi_object), &object };
527 
528 	status = acpi_get_type(handle, &acpi_type);
529 	if (ACPI_FAILURE(status))
530 		return false;
531 
532 	switch (acpi_type) {
533 	case ACPI_TYPE_PROCESSOR:
534 		status = acpi_evaluate_object(handle, NULL, NULL, &buffer);
535 		if (ACPI_FAILURE(status))
536 			return false;
537 		acpi_id = object.processor.proc_id;
538 		break;
539 	case ACPI_TYPE_DEVICE:
540 		status = acpi_evaluate_integer(handle, METHOD_NAME__UID,
541 					       NULL, &tmp);
542 		if (ACPI_FAILURE(status))
543 			return false;
544 		acpi_id = tmp;
545 		break;
546 	default:
547 		return false;
548 	}
549 
550 	if (xen_initial_domain())
551 		/*
552 		 * When running as a Xen dom0 the number of processors Linux
553 		 * sees can be different from the real number of processors on
554 		 * the system, and we still need to execute _PDC or _OSC for
555 		 * all of them.
556 		 */
557 		return xen_processor_present(acpi_id);
558 
559 	type = (acpi_type == ACPI_TYPE_DEVICE) ? 1 : 0;
560 	cpuid = acpi_get_cpuid(handle, type, acpi_id);
561 
562 	return !invalid_logical_cpuid(cpuid);
563 }
564 
565 /* vendor specific UUID indicating an Intel platform */
566 static u8 sb_uuid_str[] = "4077A616-290C-47BE-9EBD-D87058713953";
567 
568 static acpi_status __init acpi_processor_osc(acpi_handle handle, u32 lvl,
569 					     void *context, void **rv)
570 {
571 	u32 capbuf[2] = {};
572 	struct acpi_osc_context osc_context = {
573 		.uuid_str = sb_uuid_str,
574 		.rev = 1,
575 		.cap.length = 8,
576 		.cap.pointer = capbuf,
577 	};
578 	acpi_status status;
579 
580 	if (!processor_physically_present(handle))
581 		return AE_OK;
582 
583 	arch_acpi_set_proc_cap_bits(&capbuf[OSC_SUPPORT_DWORD]);
584 
585 	status = acpi_run_osc(handle, &osc_context);
586 	if (ACPI_FAILURE(status))
587 		return status;
588 
589 	kfree(osc_context.ret.pointer);
590 
591 	return AE_OK;
592 }
593 
594 static bool __init acpi_early_processor_osc(void)
595 {
596 	acpi_status status;
597 
598 	acpi_proc_quirk_mwait_check();
599 
600 	status = acpi_walk_namespace(ACPI_TYPE_PROCESSOR, ACPI_ROOT_OBJECT,
601 				     ACPI_UINT32_MAX, acpi_processor_osc, NULL,
602 				     NULL, NULL);
603 	if (ACPI_FAILURE(status))
604 		return false;
605 
606 	status = acpi_get_devices(ACPI_PROCESSOR_DEVICE_HID, acpi_processor_osc,
607 				  NULL, NULL);
608 	if (ACPI_FAILURE(status))
609 		return false;
610 
611 	return true;
612 }
613 
614 void __init acpi_early_processor_control_setup(void)
615 {
616 	if (acpi_early_processor_osc()) {
617 		pr_info("_OSC evaluated successfully for all CPUs\n");
618 	} else {
619 		pr_info("_OSC evaluation for CPUs failed, trying _PDC\n");
620 		acpi_early_processor_set_pdc();
621 	}
622 }
623 #endif
624 
625 /*
626  * The following ACPI IDs are known to be suitable for representing as
627  * processor devices.
628  */
629 static const struct acpi_device_id processor_device_ids[] = {
630 
631 	{ ACPI_PROCESSOR_OBJECT_HID, },
632 	{ ACPI_PROCESSOR_DEVICE_HID, },
633 
634 	{ }
635 };
636 
637 static struct acpi_scan_handler processor_handler = {
638 	.ids = processor_device_ids,
639 	.attach = acpi_processor_add,
640 #ifdef CONFIG_ACPI_HOTPLUG_CPU
641 	.detach = acpi_processor_remove,
642 #endif
643 	.hotplug = {
644 		.enabled = true,
645 	},
646 };
647 
648 static int acpi_processor_container_attach(struct acpi_device *dev,
649 					   const struct acpi_device_id *id)
650 {
651 	return 1;
652 }
653 
654 static const struct acpi_device_id processor_container_ids[] = {
655 	{ ACPI_PROCESSOR_CONTAINER_HID, },
656 	{ }
657 };
658 
659 static struct acpi_scan_handler processor_container_handler = {
660 	.ids = processor_container_ids,
661 	.attach = acpi_processor_container_attach,
662 };
663 
664 /* The number of the unique processor IDs */
665 static int nr_unique_ids __initdata;
666 
667 /* The number of the duplicate processor IDs */
668 static int nr_duplicate_ids;
669 
670 /* Used to store the unique processor IDs */
671 static int unique_processor_ids[] __initdata = {
672 	[0 ... NR_CPUS - 1] = -1,
673 };
674 
675 /* Used to store the duplicate processor IDs */
676 static int duplicate_processor_ids[] = {
677 	[0 ... NR_CPUS - 1] = -1,
678 };
679 
680 static void __init processor_validated_ids_update(int proc_id)
681 {
682 	int i;
683 
684 	if (nr_unique_ids == NR_CPUS||nr_duplicate_ids == NR_CPUS)
685 		return;
686 
687 	/*
688 	 * Firstly, compare the proc_id with duplicate IDs, if the proc_id is
689 	 * already in the IDs, do nothing.
690 	 */
691 	for (i = 0; i < nr_duplicate_ids; i++) {
692 		if (duplicate_processor_ids[i] == proc_id)
693 			return;
694 	}
695 
696 	/*
697 	 * Secondly, compare the proc_id with unique IDs, if the proc_id is in
698 	 * the IDs, put it in the duplicate IDs.
699 	 */
700 	for (i = 0; i < nr_unique_ids; i++) {
701 		if (unique_processor_ids[i] == proc_id) {
702 			duplicate_processor_ids[nr_duplicate_ids] = proc_id;
703 			nr_duplicate_ids++;
704 			return;
705 		}
706 	}
707 
708 	/*
709 	 * Lastly, the proc_id is a unique ID, put it in the unique IDs.
710 	 */
711 	unique_processor_ids[nr_unique_ids] = proc_id;
712 	nr_unique_ids++;
713 }
714 
715 static acpi_status __init acpi_processor_ids_walk(acpi_handle handle,
716 						  u32 lvl,
717 						  void *context,
718 						  void **rv)
719 {
720 	acpi_status status;
721 	acpi_object_type acpi_type;
722 	unsigned long long uid;
723 	union acpi_object object = { 0 };
724 	struct acpi_buffer buffer = { sizeof(union acpi_object), &object };
725 
726 	status = acpi_get_type(handle, &acpi_type);
727 	if (ACPI_FAILURE(status))
728 		return status;
729 
730 	switch (acpi_type) {
731 	case ACPI_TYPE_PROCESSOR:
732 		status = acpi_evaluate_object(handle, NULL, NULL, &buffer);
733 		if (ACPI_FAILURE(status))
734 			goto err;
735 		uid = object.processor.proc_id;
736 		break;
737 
738 	case ACPI_TYPE_DEVICE:
739 		status = acpi_evaluate_integer(handle, "_UID", NULL, &uid);
740 		if (ACPI_FAILURE(status))
741 			goto err;
742 		break;
743 	default:
744 		goto err;
745 	}
746 
747 	processor_validated_ids_update(uid);
748 	return AE_OK;
749 
750 err:
751 	/* Exit on error, but don't abort the namespace walk */
752 	acpi_handle_info(handle, "Invalid processor object\n");
753 	return AE_OK;
754 
755 }
756 
757 static void __init acpi_processor_check_duplicates(void)
758 {
759 	/* check the correctness for all processors in ACPI namespace */
760 	acpi_walk_namespace(ACPI_TYPE_PROCESSOR, ACPI_ROOT_OBJECT,
761 						ACPI_UINT32_MAX,
762 						acpi_processor_ids_walk,
763 						NULL, NULL, NULL);
764 	acpi_get_devices(ACPI_PROCESSOR_DEVICE_HID, acpi_processor_ids_walk,
765 						NULL, NULL);
766 }
767 
768 bool acpi_duplicate_processor_id(int proc_id)
769 {
770 	int i;
771 
772 	/*
773 	 * compare the proc_id with duplicate IDs, if the proc_id is already
774 	 * in the duplicate IDs, return true, otherwise, return false.
775 	 */
776 	for (i = 0; i < nr_duplicate_ids; i++) {
777 		if (duplicate_processor_ids[i] == proc_id)
778 			return true;
779 	}
780 	return false;
781 }
782 
783 void __init acpi_processor_init(void)
784 {
785 	acpi_processor_check_duplicates();
786 	acpi_scan_add_handler_with_hotplug(&processor_handler, "processor");
787 	acpi_scan_add_handler(&processor_container_handler);
788 	acpi_pcc_cpufreq_init();
789 }
790 
791 #ifdef CONFIG_ACPI_PROCESSOR_CSTATE
792 /**
793  * acpi_processor_claim_cst_control - Request _CST control from the platform.
794  */
795 bool acpi_processor_claim_cst_control(void)
796 {
797 	static bool cst_control_claimed;
798 	acpi_status status;
799 
800 	if (!acpi_gbl_FADT.cst_control || cst_control_claimed)
801 		return true;
802 
803 	status = acpi_os_write_port(acpi_gbl_FADT.smi_command,
804 				    acpi_gbl_FADT.cst_control, 8);
805 	if (ACPI_FAILURE(status)) {
806 		pr_warn("ACPI: Failed to claim processor _CST control\n");
807 		return false;
808 	}
809 
810 	cst_control_claimed = true;
811 	return true;
812 }
813 EXPORT_SYMBOL_GPL(acpi_processor_claim_cst_control);
814 
815 /**
816  * acpi_processor_evaluate_cst - Evaluate the processor _CST control method.
817  * @handle: ACPI handle of the processor object containing the _CST.
818  * @cpu: The numeric ID of the target CPU.
819  * @info: Object write the C-states information into.
820  *
821  * Extract the C-state information for the given CPU from the output of the _CST
822  * control method under the corresponding ACPI processor object (or processor
823  * device object) and populate @info with it.
824  *
825  * If any ACPI_ADR_SPACE_FIXED_HARDWARE C-states are found, invoke
826  * acpi_processor_ffh_cstate_probe() to verify them and update the
827  * cpu_cstate_entry data for @cpu.
828  */
829 int acpi_processor_evaluate_cst(acpi_handle handle, u32 cpu,
830 				struct acpi_processor_power *info)
831 {
832 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
833 	union acpi_object *cst;
834 	acpi_status status;
835 	u64 count;
836 	int last_index = 0;
837 	int i, ret = 0;
838 
839 	status = acpi_evaluate_object(handle, "_CST", NULL, &buffer);
840 	if (ACPI_FAILURE(status)) {
841 		acpi_handle_debug(handle, "No _CST\n");
842 		return -ENODEV;
843 	}
844 
845 	cst = buffer.pointer;
846 
847 	/* There must be at least 2 elements. */
848 	if (!cst || cst->type != ACPI_TYPE_PACKAGE || cst->package.count < 2) {
849 		acpi_handle_warn(handle, "Invalid _CST output\n");
850 		ret = -EFAULT;
851 		goto end;
852 	}
853 
854 	count = cst->package.elements[0].integer.value;
855 
856 	/* Validate the number of C-states. */
857 	if (count < 1 || count != cst->package.count - 1) {
858 		acpi_handle_warn(handle, "Inconsistent _CST data\n");
859 		ret = -EFAULT;
860 		goto end;
861 	}
862 
863 	for (i = 1; i <= count; i++) {
864 		union acpi_object *element;
865 		union acpi_object *obj;
866 		struct acpi_power_register *reg;
867 		struct acpi_processor_cx cx;
868 
869 		/*
870 		 * If there is not enough space for all C-states, skip the
871 		 * excess ones and log a warning.
872 		 */
873 		if (last_index >= ACPI_PROCESSOR_MAX_POWER - 1) {
874 			acpi_handle_warn(handle,
875 					 "No room for more idle states (limit: %d)\n",
876 					 ACPI_PROCESSOR_MAX_POWER - 1);
877 			break;
878 		}
879 
880 		memset(&cx, 0, sizeof(cx));
881 
882 		element = &cst->package.elements[i];
883 		if (element->type != ACPI_TYPE_PACKAGE) {
884 			acpi_handle_info(handle, "_CST C%d type(%x) is not package, skip...\n",
885 					 i, element->type);
886 			continue;
887 		}
888 
889 		if (element->package.count != 4) {
890 			acpi_handle_info(handle, "_CST C%d package count(%d) is not 4, skip...\n",
891 					 i, element->package.count);
892 			continue;
893 		}
894 
895 		obj = &element->package.elements[0];
896 
897 		if (obj->type != ACPI_TYPE_BUFFER) {
898 			acpi_handle_info(handle, "_CST C%d package element[0] type(%x) is not buffer, skip...\n",
899 					 i, obj->type);
900 			continue;
901 		}
902 
903 		reg = (struct acpi_power_register *)obj->buffer.pointer;
904 
905 		obj = &element->package.elements[1];
906 		if (obj->type != ACPI_TYPE_INTEGER) {
907 			acpi_handle_info(handle, "_CST C[%d] package element[1] type(%x) is not integer, skip...\n",
908 					 i, obj->type);
909 			continue;
910 		}
911 
912 		cx.type = obj->integer.value;
913 		/*
914 		 * There are known cases in which the _CST output does not
915 		 * contain C1, so if the type of the first state found is not
916 		 * C1, leave an empty slot for C1 to be filled in later.
917 		 */
918 		if (i == 1 && cx.type != ACPI_STATE_C1)
919 			last_index = 1;
920 
921 		cx.address = reg->address;
922 		cx.index = last_index + 1;
923 
924 		if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) {
925 			if (!acpi_processor_ffh_cstate_probe(cpu, &cx, reg)) {
926 				/*
927 				 * In the majority of cases _CST describes C1 as
928 				 * a FIXED_HARDWARE C-state, but if the command
929 				 * line forbids using MWAIT, use CSTATE_HALT for
930 				 * C1 regardless.
931 				 */
932 				if (cx.type == ACPI_STATE_C1 &&
933 				    boot_option_idle_override == IDLE_NOMWAIT) {
934 					cx.entry_method = ACPI_CSTATE_HALT;
935 					snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
936 				} else {
937 					cx.entry_method = ACPI_CSTATE_FFH;
938 				}
939 			} else if (cx.type == ACPI_STATE_C1) {
940 				/*
941 				 * In the special case of C1, FIXED_HARDWARE can
942 				 * be handled by executing the HLT instruction.
943 				 */
944 				cx.entry_method = ACPI_CSTATE_HALT;
945 				snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
946 			} else {
947 				acpi_handle_info(handle, "_CST C%d declares FIXED_HARDWARE C-state but not supported in hardware, skip...\n",
948 						 i);
949 				continue;
950 			}
951 		} else if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_IO) {
952 			cx.entry_method = ACPI_CSTATE_SYSTEMIO;
953 			snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI IOPORT 0x%x",
954 				 cx.address);
955 		} else {
956 			acpi_handle_info(handle, "_CST C%d space_id(%x) neither FIXED_HARDWARE nor SYSTEM_IO, skip...\n",
957 					 i, reg->space_id);
958 			continue;
959 		}
960 
961 		if (cx.type == ACPI_STATE_C1)
962 			cx.valid = 1;
963 
964 		obj = &element->package.elements[2];
965 		if (obj->type != ACPI_TYPE_INTEGER) {
966 			acpi_handle_info(handle, "_CST C%d package element[2] type(%x) not integer, skip...\n",
967 					 i, obj->type);
968 			continue;
969 		}
970 
971 		cx.latency = obj->integer.value;
972 
973 		obj = &element->package.elements[3];
974 		if (obj->type != ACPI_TYPE_INTEGER) {
975 			acpi_handle_info(handle, "_CST C%d package element[3] type(%x) not integer, skip...\n",
976 					 i, obj->type);
977 			continue;
978 		}
979 
980 		memcpy(&info->states[++last_index], &cx, sizeof(cx));
981 	}
982 
983 	acpi_handle_info(handle, "Found %d idle states\n", last_index);
984 
985 	info->count = last_index;
986 
987 end:
988 	kfree(buffer.pointer);
989 
990 	return ret;
991 }
992 EXPORT_SYMBOL_GPL(acpi_processor_evaluate_cst);
993 #endif /* CONFIG_ACPI_PROCESSOR_CSTATE */
994