xref: /linux/drivers/acpi/acpi_processor.c (revision 2e31b16101834bdc0b720967845d6a0a309cf27b)
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 
acpi_get_processor_handle(int cpu)38 acpi_handle acpi_get_processor_handle(int cpu)
39 {
40 	struct acpi_processor *pr;
41 
42 	pr = per_cpu(processors, cpu);
43 	if (pr)
44 		return pr->handle;
45 
46 	return NULL;
47 }
48 
acpi_processor_errata_piix4(struct pci_dev * dev)49 static int acpi_processor_errata_piix4(struct pci_dev *dev)
50 {
51 	if (!dev)
52 		return -EINVAL;
53 
54 	/*
55 	 * Note that 'dev' references the PIIX4 ACPI Controller.
56 	 */
57 
58 	switch (dev->revision) {
59 	case 0:
60 		dev_dbg(&dev->dev, "Found PIIX4 A-step\n");
61 		break;
62 	case 1:
63 		dev_dbg(&dev->dev, "Found PIIX4 B-step\n");
64 		break;
65 	case 2:
66 		dev_dbg(&dev->dev, "Found PIIX4E\n");
67 		break;
68 	case 3:
69 		dev_dbg(&dev->dev, "Found PIIX4M\n");
70 		break;
71 	default:
72 		dev_dbg(&dev->dev, "Found unknown PIIX4\n");
73 		break;
74 	}
75 
76 	switch (dev->revision) {
77 
78 	case 0:		/* PIIX4 A-step */
79 	case 1:		/* PIIX4 B-step */
80 		/*
81 		 * See specification changes #13 ("Manual Throttle Duty Cycle")
82 		 * and #14 ("Enabling and Disabling Manual Throttle"), plus
83 		 * erratum #5 ("STPCLK# Deassertion Time") from the January
84 		 * 2002 PIIX4 specification update.  Applies to only older
85 		 * PIIX4 models.
86 		 */
87 		errata.piix4.throttle = 1;
88 		fallthrough;
89 
90 	case 2:		/* PIIX4E */
91 	case 3:		/* PIIX4M */
92 		/*
93 		 * See erratum #18 ("C3 Power State/BMIDE and Type-F DMA
94 		 * Livelock") from the January 2002 PIIX4 specification update.
95 		 * Applies to all PIIX4 models.
96 		 */
97 
98 		/*
99 		 * BM-IDE
100 		 * ------
101 		 * Find the PIIX4 IDE Controller and get the Bus Master IDE
102 		 * Status register address.  We'll use this later to read
103 		 * each IDE controller's DMA status to make sure we catch all
104 		 * DMA activity.
105 		 */
106 		dev = pci_get_subsys(PCI_VENDOR_ID_INTEL,
107 				     PCI_DEVICE_ID_INTEL_82371AB,
108 				     PCI_ANY_ID, PCI_ANY_ID, NULL);
109 		if (dev) {
110 			errata.piix4.bmisx = pci_resource_start(dev, 4);
111 			if (errata.piix4.bmisx)
112 				dev_dbg(&dev->dev,
113 					"Bus master activity detection (BM-IDE) erratum enabled\n");
114 
115 			pci_dev_put(dev);
116 		}
117 
118 		/*
119 		 * Type-F DMA
120 		 * ----------
121 		 * Find the PIIX4 ISA Controller and read the Motherboard
122 		 * DMA controller's status to see if Type-F (Fast) DMA mode
123 		 * is enabled (bit 7) on either channel.  Note that we'll
124 		 * disable C3 support if this is enabled, as some legacy
125 		 * devices won't operate well if fast DMA is disabled.
126 		 */
127 		dev = pci_get_subsys(PCI_VENDOR_ID_INTEL,
128 				     PCI_DEVICE_ID_INTEL_82371AB_0,
129 				     PCI_ANY_ID, PCI_ANY_ID, NULL);
130 		if (dev) {
131 			u8 value1 = 0, value2 = 0;
132 
133 			pci_read_config_byte(dev, 0x76, &value1);
134 			pci_read_config_byte(dev, 0x77, &value2);
135 			if ((value1 & 0x80) || (value2 & 0x80)) {
136 				errata.piix4.fdma = 1;
137 				dev_dbg(&dev->dev,
138 					"Type-F DMA livelock erratum (C3 disabled)\n");
139 			}
140 			pci_dev_put(dev);
141 		}
142 
143 		break;
144 	}
145 
146 	return 0;
147 }
148 
acpi_processor_errata(void)149 static int acpi_processor_errata(void)
150 {
151 	int result = 0;
152 	struct pci_dev *dev = NULL;
153 
154 	/*
155 	 * PIIX4
156 	 */
157 	dev = pci_get_subsys(PCI_VENDOR_ID_INTEL,
158 			     PCI_DEVICE_ID_INTEL_82371AB_3, PCI_ANY_ID,
159 			     PCI_ANY_ID, NULL);
160 	if (dev) {
161 		result = acpi_processor_errata_piix4(dev);
162 		pci_dev_put(dev);
163 	}
164 
165 	return result;
166 }
167 
168 /* Create a platform device to represent a CPU frequency control mechanism. */
cpufreq_add_device(const char * name)169 static void cpufreq_add_device(const char *name)
170 {
171 	struct platform_device *pdev;
172 
173 	pdev = platform_device_register_simple(name, PLATFORM_DEVID_NONE, NULL, 0);
174 	if (IS_ERR(pdev))
175 		pr_info("%s device creation failed: %pe\n", name, pdev);
176 }
177 
178 #ifdef CONFIG_X86
179 /* Check presence of Processor Clocking Control by searching for \_SB.PCCH. */
acpi_pcc_cpufreq_init(void)180 static void __init acpi_pcc_cpufreq_init(void)
181 {
182 	acpi_status status;
183 	acpi_handle handle;
184 
185 	status = acpi_get_handle(NULL, "\\_SB", &handle);
186 	if (ACPI_FAILURE(status))
187 		return;
188 
189 	if (acpi_has_method(handle, "PCCH"))
190 		cpufreq_add_device("pcc-cpufreq");
191 }
192 #else
acpi_pcc_cpufreq_init(void)193 static void __init acpi_pcc_cpufreq_init(void) {}
194 #endif /* CONFIG_X86 */
195 
196 /* Initialization */
197 static DEFINE_PER_CPU(void *, processor_device_array);
198 
acpi_processor_set_per_cpu(struct acpi_processor * pr,struct acpi_device * device)199 static int acpi_processor_set_per_cpu(struct acpi_processor *pr,
200 				      struct acpi_device *device)
201 {
202 	BUG_ON(pr->id >= nr_cpu_ids);
203 
204 	/*
205 	 * Buggy BIOS check.
206 	 * ACPI id of processors can be reported wrongly by the BIOS.
207 	 * Don't trust it blindly
208 	 */
209 	if (per_cpu(processor_device_array, pr->id) != NULL &&
210 	    per_cpu(processor_device_array, pr->id) != device) {
211 		dev_warn(&device->dev,
212 			 "BIOS reported wrong ACPI id %d for the processor\n",
213 			 pr->id);
214 		return -EINVAL;
215 	}
216 	/*
217 	 * processor_device_array is not cleared on errors to allow buggy BIOS
218 	 * checks.
219 	 */
220 	per_cpu(processor_device_array, pr->id) = device;
221 	per_cpu(processors, pr->id) = pr;
222 
223 	return 0;
224 }
225 
226 #ifdef CONFIG_ACPI_HOTPLUG_CPU
acpi_processor_hotadd_init(struct acpi_processor * pr,struct acpi_device * device)227 static int acpi_processor_hotadd_init(struct acpi_processor *pr,
228 				      struct acpi_device *device)
229 {
230 	int ret;
231 
232 	if (invalid_phys_cpuid(pr->phys_id))
233 		return -ENODEV;
234 
235 	cpu_maps_update_begin();
236 	cpus_write_lock();
237 
238 	ret = acpi_map_cpu(pr->handle, pr->phys_id, pr->acpi_id, &pr->id);
239 	if (ret)
240 		goto out;
241 
242 	ret = acpi_processor_set_per_cpu(pr, device);
243 	if (ret) {
244 		acpi_unmap_cpu(pr->id);
245 		goto out;
246 	}
247 
248 	ret = arch_register_cpu(pr->id);
249 	if (ret) {
250 		/* Leave the processor device array in place to detect buggy bios */
251 		per_cpu(processors, pr->id) = NULL;
252 		acpi_unmap_cpu(pr->id);
253 		goto out;
254 	}
255 
256 	/*
257 	 * CPU got hot-added, but cpu_data is not initialized yet. Do
258 	 * cpu_idle/throttling initialization when the CPU gets online for
259 	 * the first time.
260 	 */
261 	pr_info("CPU%d has been hot-added\n", pr->id);
262 
263 out:
264 	cpus_write_unlock();
265 	cpu_maps_update_done();
266 	return ret;
267 }
268 #else
acpi_processor_hotadd_init(struct acpi_processor * pr,struct acpi_device * device)269 static inline int acpi_processor_hotadd_init(struct acpi_processor *pr,
270 					     struct acpi_device *device)
271 {
272 	return -ENODEV;
273 }
274 #endif /* CONFIG_ACPI_HOTPLUG_CPU */
275 
acpi_processor_get_info(struct acpi_device * device)276 static int acpi_processor_get_info(struct acpi_device *device)
277 {
278 	union acpi_object object = { .processor = { 0 } };
279 	struct acpi_buffer buffer = { sizeof(union acpi_object), &object };
280 	struct acpi_processor *pr = acpi_driver_data(device);
281 	int device_declaration = 0;
282 	acpi_status status = AE_OK;
283 	static int cpu0_initialized;
284 	unsigned long long value;
285 	int ret;
286 
287 	acpi_processor_errata();
288 
289 	/*
290 	 * Check to see if we have bus mastering arbitration control.  This
291 	 * is required for proper C3 usage (to maintain cache coherency).
292 	 */
293 	if (acpi_gbl_FADT.pm2_control_block && acpi_gbl_FADT.pm2_control_length) {
294 		pr->flags.bm_control = 1;
295 		dev_dbg(&device->dev, "Bus mastering arbitration control present\n");
296 	} else
297 		dev_dbg(&device->dev, "No bus mastering arbitration control\n");
298 
299 	if (!strcmp(acpi_device_hid(device), ACPI_PROCESSOR_OBJECT_HID)) {
300 		/* Declared with "Processor" statement; match ProcessorID */
301 		status = acpi_evaluate_object(pr->handle, NULL, NULL, &buffer);
302 		if (ACPI_FAILURE(status)) {
303 			dev_err(&device->dev,
304 				"Failed to evaluate processor object (0x%x)\n",
305 				status);
306 			return -ENODEV;
307 		}
308 
309 		pr->acpi_id = object.processor.proc_id;
310 	} else {
311 		/*
312 		 * Declared with "Device" statement; match _UID.
313 		 */
314 		status = acpi_evaluate_integer(pr->handle, METHOD_NAME__UID,
315 						NULL, &value);
316 		if (ACPI_FAILURE(status)) {
317 			dev_err(&device->dev,
318 				"Failed to evaluate processor _UID (0x%x)\n",
319 				status);
320 			return -ENODEV;
321 		}
322 		device_declaration = 1;
323 		pr->acpi_id = value;
324 	}
325 
326 	if (acpi_duplicate_processor_id(pr->acpi_id)) {
327 		if (pr->acpi_id == 0xff)
328 			dev_info_once(&device->dev,
329 				"Entry not well-defined, consider updating BIOS\n");
330 		else
331 			dev_err(&device->dev,
332 				"Failed to get unique processor _UID (0x%x)\n",
333 				pr->acpi_id);
334 		return -ENODEV;
335 	}
336 
337 	pr->phys_id = acpi_get_phys_id(pr->handle, device_declaration,
338 					pr->acpi_id);
339 	if (invalid_phys_cpuid(pr->phys_id))
340 		dev_dbg(&device->dev, "Failed to get CPU physical ID.\n");
341 
342 	pr->id = acpi_map_cpuid(pr->phys_id, pr->acpi_id);
343 	if (!cpu0_initialized) {
344 		cpu0_initialized = 1;
345 		/*
346 		 * Handle UP system running SMP kernel, with no CPU
347 		 * entry in MADT
348 		 */
349 		if (!acpi_has_cpu_in_madt() && invalid_logical_cpuid(pr->id) &&
350 		    (num_online_cpus() == 1))
351 			pr->id = 0;
352 		/*
353 		 * Check availability of Processor Performance Control by
354 		 * looking at the presence of the _PCT object under the first
355 		 * processor definition.
356 		 */
357 		if (acpi_has_method(pr->handle, "_PCT"))
358 			cpufreq_add_device("acpi-cpufreq");
359 	}
360 
361 	/*
362 	 *  This code is not called unless we know the CPU is present and
363 	 *  enabled. The two paths are:
364 	 *  a) Initially present CPUs on architectures that do not defer
365 	 *     their arch_register_cpu() calls until this point.
366 	 *  b) Hotplugged CPUs (enabled bit in _STA has transitioned from not
367 	 *     enabled to enabled)
368 	 */
369 	if (!get_cpu_device(pr->id))
370 		ret = acpi_processor_hotadd_init(pr, device);
371 	else
372 		ret = acpi_processor_set_per_cpu(pr, device);
373 	if (ret)
374 		return ret;
375 
376 	/*
377 	 * On some boxes several processors use the same processor bus id.
378 	 * But they are located in different scope. For example:
379 	 * \_SB.SCK0.CPU0
380 	 * \_SB.SCK1.CPU0
381 	 * Rename the processor device bus id. And the new bus id will be
382 	 * generated as the following format:
383 	 * CPU+CPU ID.
384 	 */
385 	sprintf(acpi_device_bid(device), "CPU%X", pr->id);
386 	dev_dbg(&device->dev, "Processor [%d:%d]\n", pr->id, pr->acpi_id);
387 
388 	if (!object.processor.pblk_address)
389 		dev_dbg(&device->dev, "No PBLK (NULL address)\n");
390 	else if (object.processor.pblk_length != 6)
391 		dev_err(&device->dev, "Invalid PBLK length [%d]\n",
392 			    object.processor.pblk_length);
393 	else {
394 		pr->throttling.address = object.processor.pblk_address;
395 		pr->throttling.duty_offset = acpi_gbl_FADT.duty_offset;
396 		pr->throttling.duty_width = acpi_gbl_FADT.duty_width;
397 
398 		pr->pblk = object.processor.pblk_address;
399 	}
400 
401 	/*
402 	 * If ACPI describes a slot number for this CPU, we can use it to
403 	 * ensure we get the right value in the "physical id" field
404 	 * of /proc/cpuinfo
405 	 */
406 	status = acpi_evaluate_integer(pr->handle, "_SUN", NULL, &value);
407 	if (ACPI_SUCCESS(status))
408 		arch_fix_phys_package_id(pr->id, value);
409 
410 	return 0;
411 }
412 
413 /*
414  * Do not put anything in here which needs the core to be online.
415  * For example MSR access or setting up things which check for cpuinfo_x86
416  * (cpu_data(cpu)) values, like CPU feature flags, family, model, etc.
417  * Such things have to be put in and set up by the processor driver's .probe().
418  */
acpi_processor_add(struct acpi_device * device,const struct acpi_device_id * id)419 static int acpi_processor_add(struct acpi_device *device,
420 					const struct acpi_device_id *id)
421 {
422 	struct acpi_processor *pr;
423 	struct device *dev;
424 	int result = 0;
425 
426 	if (!acpi_device_is_enabled(device))
427 		return -ENODEV;
428 
429 	pr = kzalloc_obj(struct acpi_processor);
430 	if (!pr)
431 		return -ENOMEM;
432 
433 	if (!zalloc_cpumask_var(&pr->throttling.shared_cpu_map, GFP_KERNEL)) {
434 		result = -ENOMEM;
435 		goto err_free_pr;
436 	}
437 
438 	pr->handle = device->handle;
439 	device->driver_data = pr;
440 
441 	result = acpi_processor_get_info(device);
442 	if (result) /* Processor is not physically present or unavailable */
443 		goto err_clear_driver_data;
444 
445 	dev = get_cpu_device(pr->id);
446 	if (!dev) {
447 		result = -ENODEV;
448 		goto err_clear_per_cpu;
449 	}
450 
451 	result = acpi_bind_one(dev, device);
452 	if (result)
453 		goto err_clear_per_cpu;
454 
455 	pr->dev = dev;
456 
457 	/* Trigger the processor driver's .probe() if present. */
458 	if (device_attach(dev) >= 0)
459 		return 1;
460 
461 	dev_err(dev, "Processor driver could not be attached\n");
462 	acpi_unbind_one(dev);
463 
464  err_clear_per_cpu:
465 	per_cpu(processors, pr->id) = NULL;
466  err_clear_driver_data:
467 	device->driver_data = NULL;
468 	free_cpumask_var(pr->throttling.shared_cpu_map);
469  err_free_pr:
470 	kfree(pr);
471 	return result;
472 }
473 
474 #ifdef CONFIG_ACPI_HOTPLUG_CPU
475 /* Removal */
acpi_processor_post_eject(struct acpi_device * device)476 static void acpi_processor_post_eject(struct acpi_device *device)
477 {
478 	struct acpi_processor *pr;
479 
480 	if (!device || !acpi_driver_data(device))
481 		return;
482 
483 	pr = acpi_driver_data(device);
484 	if (pr->id >= nr_cpu_ids)
485 		goto out;
486 
487 	/*
488 	 * The only reason why we ever get here is CPU hot-removal.  The CPU is
489 	 * already offline and the ACPI device removal locking prevents it from
490 	 * being put back online at this point.
491 	 *
492 	 * Unbind the driver from the processor device and detach it from the
493 	 * ACPI companion object.
494 	 */
495 	device_release_driver(pr->dev);
496 	acpi_unbind_one(pr->dev);
497 
498 	cpu_maps_update_begin();
499 	cpus_write_lock();
500 
501 	/* Remove the CPU. */
502 	arch_unregister_cpu(pr->id);
503 	acpi_unmap_cpu(pr->id);
504 
505 	/* Clean up. */
506 	per_cpu(processor_device_array, pr->id) = NULL;
507 	per_cpu(processors, pr->id) = NULL;
508 
509 	cpus_write_unlock();
510 	cpu_maps_update_done();
511 
512 	try_offline_node(cpu_to_node(pr->id));
513 
514  out:
515 	free_cpumask_var(pr->throttling.shared_cpu_map);
516 	kfree(pr);
517 }
518 #endif /* CONFIG_ACPI_HOTPLUG_CPU */
519 
520 #ifdef CONFIG_ARCH_MIGHT_HAVE_ACPI_PDC
processor_physically_present(acpi_handle handle)521 bool __init processor_physically_present(acpi_handle handle)
522 {
523 	int cpuid, type;
524 	u32 acpi_id;
525 	acpi_status status;
526 	acpi_object_type acpi_type;
527 	unsigned long long tmp;
528 	union acpi_object object = {};
529 	struct acpi_buffer buffer = { sizeof(union acpi_object), &object };
530 
531 	status = acpi_get_type(handle, &acpi_type);
532 	if (ACPI_FAILURE(status))
533 		return false;
534 
535 	switch (acpi_type) {
536 	case ACPI_TYPE_PROCESSOR:
537 		status = acpi_evaluate_object(handle, NULL, NULL, &buffer);
538 		if (ACPI_FAILURE(status))
539 			return false;
540 		acpi_id = object.processor.proc_id;
541 		break;
542 	case ACPI_TYPE_DEVICE:
543 		status = acpi_evaluate_integer(handle, METHOD_NAME__UID,
544 					       NULL, &tmp);
545 		if (ACPI_FAILURE(status))
546 			return false;
547 		acpi_id = tmp;
548 		break;
549 	default:
550 		return false;
551 	}
552 
553 	if (xen_initial_domain())
554 		/*
555 		 * When running as a Xen dom0 the number of processors Linux
556 		 * sees can be different from the real number of processors on
557 		 * the system, and we still need to execute _PDC or _OSC for
558 		 * all of them.
559 		 */
560 		return xen_processor_present(acpi_id);
561 
562 	type = (acpi_type == ACPI_TYPE_DEVICE) ? 1 : 0;
563 	cpuid = acpi_get_cpuid(handle, type, acpi_id);
564 
565 	return !invalid_logical_cpuid(cpuid);
566 }
567 
568 /* vendor specific UUID indicating an Intel platform */
569 static u8 sb_uuid_str[] = "4077A616-290C-47BE-9EBD-D87058713953";
570 
acpi_processor_osc(acpi_handle handle,u32 lvl,void * context,void ** rv)571 static acpi_status __init acpi_processor_osc(acpi_handle handle, u32 lvl,
572 					     void *context, void **rv)
573 {
574 	u32 capbuf[2] = {};
575 	struct acpi_osc_context osc_context = {
576 		.uuid_str = sb_uuid_str,
577 		.rev = 1,
578 		.cap.length = 8,
579 		.cap.pointer = capbuf,
580 	};
581 	acpi_status status;
582 
583 	if (!processor_physically_present(handle))
584 		return AE_OK;
585 
586 	arch_acpi_set_proc_cap_bits(&capbuf[OSC_SUPPORT_DWORD]);
587 
588 	status = acpi_run_osc(handle, &osc_context);
589 	if (ACPI_FAILURE(status))
590 		return status;
591 
592 	kfree(osc_context.ret.pointer);
593 
594 	return AE_OK;
595 }
596 
acpi_early_processor_osc(void)597 static bool __init acpi_early_processor_osc(void)
598 {
599 	acpi_status status;
600 
601 	acpi_proc_quirk_mwait_check();
602 
603 	status = acpi_walk_namespace(ACPI_TYPE_PROCESSOR, ACPI_ROOT_OBJECT,
604 				     ACPI_UINT32_MAX, acpi_processor_osc, NULL,
605 				     NULL, NULL);
606 	if (ACPI_FAILURE(status))
607 		return false;
608 
609 	status = acpi_get_devices(ACPI_PROCESSOR_DEVICE_HID, acpi_processor_osc,
610 				  NULL, NULL);
611 	if (ACPI_FAILURE(status))
612 		return false;
613 
614 	return true;
615 }
616 
acpi_early_processor_control_setup(void)617 void __init acpi_early_processor_control_setup(void)
618 {
619 	if (acpi_early_processor_osc()) {
620 		pr_debug("_OSC evaluated successfully for all CPUs\n");
621 	} else {
622 		pr_debug("_OSC evaluation for CPUs failed, trying _PDC\n");
623 		acpi_early_processor_set_pdc();
624 	}
625 }
626 #endif
627 
628 /*
629  * The following ACPI IDs are known to be suitable for representing as
630  * processor devices.
631  */
632 static const struct acpi_device_id processor_device_ids[] = {
633 
634 	{ ACPI_PROCESSOR_OBJECT_HID, },
635 	{ ACPI_PROCESSOR_DEVICE_HID, },
636 
637 	{ }
638 };
639 
640 static struct acpi_scan_handler processor_handler = {
641 	.ids = processor_device_ids,
642 	.attach = acpi_processor_add,
643 #ifdef CONFIG_ACPI_HOTPLUG_CPU
644 	.post_eject = acpi_processor_post_eject,
645 #endif
646 	.hotplug = {
647 		.enabled = true,
648 	},
649 };
650 
acpi_processor_container_attach(struct acpi_device * dev,const struct acpi_device_id * id)651 static int acpi_processor_container_attach(struct acpi_device *dev,
652 					   const struct acpi_device_id *id)
653 {
654 	return 1;
655 }
656 
657 static const struct acpi_device_id processor_container_ids[] = {
658 	{ ACPI_PROCESSOR_CONTAINER_HID, },
659 	{ }
660 };
661 
662 static struct acpi_scan_handler processor_container_handler = {
663 	.ids = processor_container_ids,
664 	.attach = acpi_processor_container_attach,
665 };
666 
667 /* The number of the unique processor IDs */
668 static int nr_unique_ids __initdata;
669 
670 /* The number of the duplicate processor IDs */
671 static int nr_duplicate_ids;
672 
673 /* Used to store the unique processor IDs */
674 static int unique_processor_ids[] __initdata = {
675 	[0 ... NR_CPUS - 1] = -1,
676 };
677 
678 /* Used to store the duplicate processor IDs */
679 static int duplicate_processor_ids[] = {
680 	[0 ... NR_CPUS - 1] = -1,
681 };
682 
processor_validated_ids_update(int proc_id)683 static void __init processor_validated_ids_update(int proc_id)
684 {
685 	int i;
686 
687 	if (nr_unique_ids == NR_CPUS||nr_duplicate_ids == NR_CPUS)
688 		return;
689 
690 	/*
691 	 * Firstly, compare the proc_id with duplicate IDs, if the proc_id is
692 	 * already in the IDs, do nothing.
693 	 */
694 	for (i = 0; i < nr_duplicate_ids; i++) {
695 		if (duplicate_processor_ids[i] == proc_id)
696 			return;
697 	}
698 
699 	/*
700 	 * Secondly, compare the proc_id with unique IDs, if the proc_id is in
701 	 * the IDs, put it in the duplicate IDs.
702 	 */
703 	for (i = 0; i < nr_unique_ids; i++) {
704 		if (unique_processor_ids[i] == proc_id) {
705 			duplicate_processor_ids[nr_duplicate_ids] = proc_id;
706 			nr_duplicate_ids++;
707 			return;
708 		}
709 	}
710 
711 	/*
712 	 * Lastly, the proc_id is a unique ID, put it in the unique IDs.
713 	 */
714 	unique_processor_ids[nr_unique_ids] = proc_id;
715 	nr_unique_ids++;
716 }
717 
acpi_processor_ids_walk(acpi_handle handle,u32 lvl,void * context,void ** rv)718 static acpi_status __init acpi_processor_ids_walk(acpi_handle handle,
719 						  u32 lvl,
720 						  void *context,
721 						  void **rv)
722 {
723 	acpi_status status;
724 	acpi_object_type acpi_type;
725 	unsigned long long uid;
726 	union acpi_object object = { 0 };
727 	struct acpi_buffer buffer = { sizeof(union acpi_object), &object };
728 
729 	status = acpi_get_type(handle, &acpi_type);
730 	if (ACPI_FAILURE(status))
731 		return status;
732 
733 	switch (acpi_type) {
734 	case ACPI_TYPE_PROCESSOR:
735 		status = acpi_evaluate_object(handle, NULL, NULL, &buffer);
736 		if (ACPI_FAILURE(status))
737 			goto err;
738 		uid = object.processor.proc_id;
739 		break;
740 
741 	case ACPI_TYPE_DEVICE:
742 		status = acpi_evaluate_integer(handle, "_UID", NULL, &uid);
743 		if (ACPI_FAILURE(status))
744 			goto err;
745 		break;
746 	default:
747 		goto err;
748 	}
749 
750 	processor_validated_ids_update(uid);
751 	return AE_OK;
752 
753 err:
754 	/* Exit on error, but don't abort the namespace walk */
755 	acpi_handle_info(handle, "Invalid processor object\n");
756 	return AE_OK;
757 
758 }
759 
acpi_processor_check_duplicates(void)760 static void __init acpi_processor_check_duplicates(void)
761 {
762 	/* check the correctness for all processors in ACPI namespace */
763 	acpi_walk_namespace(ACPI_TYPE_PROCESSOR, ACPI_ROOT_OBJECT,
764 						ACPI_UINT32_MAX,
765 						acpi_processor_ids_walk,
766 						NULL, NULL, NULL);
767 	acpi_get_devices(ACPI_PROCESSOR_DEVICE_HID, acpi_processor_ids_walk,
768 						NULL, NULL);
769 }
770 
acpi_duplicate_processor_id(int proc_id)771 bool acpi_duplicate_processor_id(int proc_id)
772 {
773 	int i;
774 
775 	/*
776 	 * compare the proc_id with duplicate IDs, if the proc_id is already
777 	 * in the duplicate IDs, return true, otherwise, return false.
778 	 */
779 	for (i = 0; i < nr_duplicate_ids; i++) {
780 		if (duplicate_processor_ids[i] == proc_id)
781 			return true;
782 	}
783 	return false;
784 }
785 
acpi_processor_init(void)786 void __init acpi_processor_init(void)
787 {
788 	acpi_processor_check_duplicates();
789 	acpi_scan_add_handler_with_hotplug(&processor_handler, "processor");
790 	acpi_scan_add_handler(&processor_container_handler);
791 	acpi_pcc_cpufreq_init();
792 }
793 
794 #ifdef CONFIG_ACPI_PROCESSOR_CSTATE
795 /**
796  * acpi_processor_claim_cst_control - Request _CST control from the platform.
797  */
acpi_processor_claim_cst_control(void)798 bool acpi_processor_claim_cst_control(void)
799 {
800 	static bool cst_control_claimed;
801 	acpi_status status;
802 
803 	if (!acpi_gbl_FADT.cst_control || cst_control_claimed)
804 		return true;
805 
806 	status = acpi_os_write_port(acpi_gbl_FADT.smi_command,
807 				    acpi_gbl_FADT.cst_control, 8);
808 	if (ACPI_FAILURE(status)) {
809 		pr_warn("ACPI: Failed to claim processor _CST control\n");
810 		return false;
811 	}
812 
813 	cst_control_claimed = true;
814 	return true;
815 }
816 EXPORT_SYMBOL_NS_GPL(acpi_processor_claim_cst_control, "ACPI_PROCESSOR_IDLE");
817 
818 /**
819  * acpi_processor_evaluate_cst - Evaluate the processor _CST control method.
820  * @handle: ACPI handle of the processor object containing the _CST.
821  * @cpu: The numeric ID of the target CPU.
822  * @info: Object write the C-states information into.
823  *
824  * Extract the C-state information for the given CPU from the output of the _CST
825  * control method under the corresponding ACPI processor object (or processor
826  * device object) and populate @info with it.
827  *
828  * If any ACPI_ADR_SPACE_FIXED_HARDWARE C-states are found, invoke
829  * acpi_processor_ffh_cstate_probe() to verify them and update the
830  * cpu_cstate_entry data for @cpu.
831  */
acpi_processor_evaluate_cst(acpi_handle handle,u32 cpu,struct acpi_processor_power * info)832 int acpi_processor_evaluate_cst(acpi_handle handle, u32 cpu,
833 				struct acpi_processor_power *info)
834 {
835 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
836 	union acpi_object *cst;
837 	acpi_status status;
838 	u64 count;
839 	int last_index = 0;
840 	int i, ret = 0;
841 
842 	status = acpi_evaluate_object(handle, "_CST", NULL, &buffer);
843 	if (ACPI_FAILURE(status)) {
844 		acpi_handle_debug(handle, "No _CST\n");
845 		return -ENODEV;
846 	}
847 
848 	cst = buffer.pointer;
849 
850 	/* There must be at least 2 elements. */
851 	if (!cst || cst->type != ACPI_TYPE_PACKAGE || cst->package.count < 2) {
852 		acpi_handle_warn(handle, "Invalid _CST output\n");
853 		ret = -EFAULT;
854 		goto end;
855 	}
856 
857 	count = cst->package.elements[0].integer.value;
858 
859 	/* Validate the number of C-states. */
860 	if (count < 1 || count != cst->package.count - 1) {
861 		acpi_handle_warn(handle, "Inconsistent _CST data\n");
862 		ret = -EFAULT;
863 		goto end;
864 	}
865 
866 	for (i = 1; i <= count; i++) {
867 		union acpi_object *element;
868 		union acpi_object *obj;
869 		struct acpi_power_register *reg;
870 		struct acpi_processor_cx cx;
871 
872 		/*
873 		 * If there is not enough space for all C-states, skip the
874 		 * excess ones and log a warning.
875 		 */
876 		if (last_index >= ACPI_PROCESSOR_MAX_POWER - 1) {
877 			acpi_handle_warn(handle,
878 					 "No room for more idle states (limit: %d)\n",
879 					 ACPI_PROCESSOR_MAX_POWER - 1);
880 			break;
881 		}
882 
883 		memset(&cx, 0, sizeof(cx));
884 
885 		element = &cst->package.elements[i];
886 		if (element->type != ACPI_TYPE_PACKAGE) {
887 			acpi_handle_info(handle, "_CST C%d type(%x) is not package, skip...\n",
888 					 i, element->type);
889 			continue;
890 		}
891 
892 		if (element->package.count != 4) {
893 			acpi_handle_info(handle, "_CST C%d package count(%d) is not 4, skip...\n",
894 					 i, element->package.count);
895 			continue;
896 		}
897 
898 		obj = &element->package.elements[0];
899 
900 		if (obj->type != ACPI_TYPE_BUFFER) {
901 			acpi_handle_info(handle, "_CST C%d package element[0] type(%x) is not buffer, skip...\n",
902 					 i, obj->type);
903 			continue;
904 		}
905 
906 		reg = (struct acpi_power_register *)obj->buffer.pointer;
907 
908 		obj = &element->package.elements[1];
909 		if (obj->type != ACPI_TYPE_INTEGER) {
910 			acpi_handle_info(handle, "_CST C[%d] package element[1] type(%x) is not integer, skip...\n",
911 					 i, obj->type);
912 			continue;
913 		}
914 
915 		cx.type = obj->integer.value;
916 		/*
917 		 * There are known cases in which the _CST output does not
918 		 * contain C1, so if the type of the first state found is not
919 		 * C1, leave an empty slot for C1 to be filled in later.
920 		 */
921 		if (i == 1 && cx.type != ACPI_STATE_C1)
922 			last_index = 1;
923 
924 		cx.address = reg->address;
925 		cx.index = last_index + 1;
926 
927 		if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) {
928 			if (!acpi_processor_ffh_cstate_probe(cpu, &cx, reg)) {
929 				/*
930 				 * In the majority of cases _CST describes C1 as
931 				 * a FIXED_HARDWARE C-state, but if the command
932 				 * line forbids using MWAIT, use CSTATE_HALT for
933 				 * C1 regardless.
934 				 */
935 				if (cx.type == ACPI_STATE_C1 &&
936 				    boot_option_idle_override == IDLE_NOMWAIT) {
937 					cx.entry_method = ACPI_CSTATE_HALT;
938 					snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
939 				} else {
940 					cx.entry_method = ACPI_CSTATE_FFH;
941 				}
942 			} else if (cx.type == ACPI_STATE_C1) {
943 				/*
944 				 * In the special case of C1, FIXED_HARDWARE can
945 				 * be handled by executing the HLT instruction.
946 				 */
947 				cx.entry_method = ACPI_CSTATE_HALT;
948 				snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
949 			} else {
950 				acpi_handle_info(handle, "_CST C%d declares FIXED_HARDWARE C-state but not supported in hardware, skip...\n",
951 						 i);
952 				continue;
953 			}
954 		} else if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_IO) {
955 			cx.entry_method = ACPI_CSTATE_SYSTEMIO;
956 			snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI IOPORT 0x%x",
957 				 cx.address);
958 		} else {
959 			acpi_handle_info(handle, "_CST C%d space_id(%x) neither FIXED_HARDWARE nor SYSTEM_IO, skip...\n",
960 					 i, reg->space_id);
961 			continue;
962 		}
963 
964 		if (cx.type == ACPI_STATE_C1)
965 			cx.valid = 1;
966 
967 		obj = &element->package.elements[2];
968 		if (obj->type != ACPI_TYPE_INTEGER) {
969 			acpi_handle_info(handle, "_CST C%d package element[2] type(%x) not integer, skip...\n",
970 					 i, obj->type);
971 			continue;
972 		}
973 
974 		cx.latency = obj->integer.value;
975 
976 		obj = &element->package.elements[3];
977 		if (obj->type != ACPI_TYPE_INTEGER) {
978 			acpi_handle_info(handle, "_CST C%d package element[3] type(%x) not integer, skip...\n",
979 					 i, obj->type);
980 			continue;
981 		}
982 
983 		memcpy(&info->states[++last_index], &cx, sizeof(cx));
984 	}
985 
986 	acpi_handle_debug(handle, "Found %d idle states\n", last_index);
987 
988 	info->count = last_index;
989 
990 end:
991 	kfree(buffer.pointer);
992 
993 	return ret;
994 }
995 EXPORT_SYMBOL_NS_GPL(acpi_processor_evaluate_cst, "ACPI_PROCESSOR_IDLE");
996 #endif /* CONFIG_ACPI_PROCESSOR_CSTATE */
997