tools headers UAPI: Sync files changed by the quotactl_path unwiring
[linux-2.6-microblaze.git] / drivers / acpi / acpi_processor.c
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
13 #include <linux/acpi.h>
14 #include <linux/device.h>
15 #include <linux/kernel.h>
16 #include <linux/module.h>
17 #include <linux/pci.h>
18
19 #include <acpi/processor.h>
20
21 #include <asm/cpu.h>
22
23 #include "internal.h"
24
25 DEFINE_PER_CPU(struct acpi_processor *, processors);
26 EXPORT_PER_CPU_SYMBOL(processors);
27
28 /* Errata Handling */
29 struct acpi_processor_errata errata __read_mostly;
30 EXPORT_SYMBOL_GPL(errata);
31
32 static int acpi_processor_errata_piix4(struct pci_dev *dev)
33 {
34         u8 value1 = 0;
35         u8 value2 = 0;
36
37
38         if (!dev)
39                 return -EINVAL;
40
41         /*
42          * Note that 'dev' references the PIIX4 ACPI Controller.
43          */
44
45         switch (dev->revision) {
46         case 0:
47                 dev_dbg(&dev->dev, "Found PIIX4 A-step\n");
48                 break;
49         case 1:
50                 dev_dbg(&dev->dev, "Found PIIX4 B-step\n");
51                 break;
52         case 2:
53                 dev_dbg(&dev->dev, "Found PIIX4E\n");
54                 break;
55         case 3:
56                 dev_dbg(&dev->dev, "Found PIIX4M\n");
57                 break;
58         default:
59                 dev_dbg(&dev->dev, "Found unknown PIIX4\n");
60                 break;
61         }
62
63         switch (dev->revision) {
64
65         case 0:         /* PIIX4 A-step */
66         case 1:         /* PIIX4 B-step */
67                 /*
68                  * See specification changes #13 ("Manual Throttle Duty Cycle")
69                  * and #14 ("Enabling and Disabling Manual Throttle"), plus
70                  * erratum #5 ("STPCLK# Deassertion Time") from the January
71                  * 2002 PIIX4 specification update.  Applies to only older
72                  * PIIX4 models.
73                  */
74                 errata.piix4.throttle = 1;
75                 fallthrough;
76
77         case 2:         /* PIIX4E */
78         case 3:         /* PIIX4M */
79                 /*
80                  * See erratum #18 ("C3 Power State/BMIDE and Type-F DMA
81                  * Livelock") from the January 2002 PIIX4 specification update.
82                  * Applies to all PIIX4 models.
83                  */
84
85                 /*
86                  * BM-IDE
87                  * ------
88                  * Find the PIIX4 IDE Controller and get the Bus Master IDE
89                  * Status register address.  We'll use this later to read
90                  * each IDE controller's DMA status to make sure we catch all
91                  * DMA activity.
92                  */
93                 dev = pci_get_subsys(PCI_VENDOR_ID_INTEL,
94                                      PCI_DEVICE_ID_INTEL_82371AB,
95                                      PCI_ANY_ID, PCI_ANY_ID, NULL);
96                 if (dev) {
97                         errata.piix4.bmisx = pci_resource_start(dev, 4);
98                         pci_dev_put(dev);
99                 }
100
101                 /*
102                  * Type-F DMA
103                  * ----------
104                  * Find the PIIX4 ISA Controller and read the Motherboard
105                  * DMA controller's status to see if Type-F (Fast) DMA mode
106                  * is enabled (bit 7) on either channel.  Note that we'll
107                  * disable C3 support if this is enabled, as some legacy
108                  * devices won't operate well if fast DMA is disabled.
109                  */
110                 dev = pci_get_subsys(PCI_VENDOR_ID_INTEL,
111                                      PCI_DEVICE_ID_INTEL_82371AB_0,
112                                      PCI_ANY_ID, PCI_ANY_ID, NULL);
113                 if (dev) {
114                         pci_read_config_byte(dev, 0x76, &value1);
115                         pci_read_config_byte(dev, 0x77, &value2);
116                         if ((value1 & 0x80) || (value2 & 0x80))
117                                 errata.piix4.fdma = 1;
118                         pci_dev_put(dev);
119                 }
120
121                 break;
122         }
123
124         if (errata.piix4.bmisx)
125                 dev_dbg(&dev->dev, "Bus master activity detection (BM-IDE) erratum enabled\n");
126         if (errata.piix4.fdma)
127                 dev_dbg(&dev->dev, "Type-F DMA livelock erratum (C3 disabled)\n");
128
129         return 0;
130 }
131
132 static int acpi_processor_errata(void)
133 {
134         int result = 0;
135         struct pci_dev *dev = NULL;
136
137         /*
138          * PIIX4
139          */
140         dev = pci_get_subsys(PCI_VENDOR_ID_INTEL,
141                              PCI_DEVICE_ID_INTEL_82371AB_3, PCI_ANY_ID,
142                              PCI_ANY_ID, NULL);
143         if (dev) {
144                 result = acpi_processor_errata_piix4(dev);
145                 pci_dev_put(dev);
146         }
147
148         return result;
149 }
150
151 /* Initialization */
152 #ifdef CONFIG_ACPI_HOTPLUG_CPU
153 int __weak acpi_map_cpu(acpi_handle handle,
154                 phys_cpuid_t physid, u32 acpi_id, int *pcpu)
155 {
156         return -ENODEV;
157 }
158
159 int __weak acpi_unmap_cpu(int cpu)
160 {
161         return -ENODEV;
162 }
163
164 int __weak arch_register_cpu(int cpu)
165 {
166         return -ENODEV;
167 }
168
169 void __weak arch_unregister_cpu(int cpu) {}
170
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         if (invalid_phys_cpuid(pr->phys_id))
178                 return -ENODEV;
179
180         status = acpi_evaluate_integer(pr->handle, "_STA", NULL, &sta);
181         if (ACPI_FAILURE(status) || !(sta & ACPI_STA_DEVICE_PRESENT))
182                 return -ENODEV;
183
184         cpu_maps_update_begin();
185         cpu_hotplug_begin();
186
187         ret = acpi_map_cpu(pr->handle, pr->phys_id, pr->acpi_id, &pr->id);
188         if (ret)
189                 goto out;
190
191         ret = arch_register_cpu(pr->id);
192         if (ret) {
193                 acpi_unmap_cpu(pr->id);
194                 goto out;
195         }
196
197         /*
198          * CPU got hot-added, but cpu_data is not initialized yet.  Set a flag
199          * to delay cpu_idle/throttling initialization and do it when the CPU
200          * gets online for the first time.
201          */
202         pr_info("CPU%d has been hot-added\n", pr->id);
203         pr->flags.need_hotplug_init = 1;
204
205 out:
206         cpu_hotplug_done();
207         cpu_maps_update_done();
208         return ret;
209 }
210 #else
211 static inline int acpi_processor_hotadd_init(struct acpi_processor *pr)
212 {
213         return -ENODEV;
214 }
215 #endif /* CONFIG_ACPI_HOTPLUG_CPU */
216
217 static int acpi_processor_get_info(struct acpi_device *device)
218 {
219         union acpi_object object = { 0 };
220         struct acpi_buffer buffer = { sizeof(union acpi_object), &object };
221         struct acpi_processor *pr = acpi_driver_data(device);
222         int device_declaration = 0;
223         acpi_status status = AE_OK;
224         static int cpu0_initialized;
225         unsigned long long value;
226
227         acpi_processor_errata();
228
229         /*
230          * Check to see if we have bus mastering arbitration control.  This
231          * is required for proper C3 usage (to maintain cache coherency).
232          */
233         if (acpi_gbl_FADT.pm2_control_block && acpi_gbl_FADT.pm2_control_length) {
234                 pr->flags.bm_control = 1;
235                 dev_dbg(&device->dev, "Bus mastering arbitration control present\n");
236         } else
237                 dev_dbg(&device->dev, "No bus mastering arbitration control\n");
238
239         if (!strcmp(acpi_device_hid(device), ACPI_PROCESSOR_OBJECT_HID)) {
240                 /* Declared with "Processor" statement; match ProcessorID */
241                 status = acpi_evaluate_object(pr->handle, NULL, NULL, &buffer);
242                 if (ACPI_FAILURE(status)) {
243                         dev_err(&device->dev,
244                                 "Failed to evaluate processor object (0x%x)\n",
245                                 status);
246                         return -ENODEV;
247                 }
248
249                 pr->acpi_id = object.processor.proc_id;
250         } else {
251                 /*
252                  * Declared with "Device" statement; match _UID.
253                  */
254                 status = acpi_evaluate_integer(pr->handle, METHOD_NAME__UID,
255                                                 NULL, &value);
256                 if (ACPI_FAILURE(status)) {
257                         dev_err(&device->dev,
258                                 "Failed to evaluate processor _UID (0x%x)\n",
259                                 status);
260                         return -ENODEV;
261                 }
262                 device_declaration = 1;
263                 pr->acpi_id = value;
264         }
265
266         if (acpi_duplicate_processor_id(pr->acpi_id)) {
267                 if (pr->acpi_id == 0xff)
268                         dev_info_once(&device->dev,
269                                 "Entry not well-defined, consider updating BIOS\n");
270                 else
271                         dev_err(&device->dev,
272                                 "Failed to get unique processor _UID (0x%x)\n",
273                                 pr->acpi_id);
274                 return -ENODEV;
275         }
276
277         pr->phys_id = acpi_get_phys_id(pr->handle, device_declaration,
278                                         pr->acpi_id);
279         if (invalid_phys_cpuid(pr->phys_id))
280                 dev_dbg(&device->dev, "Failed to get CPU physical ID.\n");
281
282         pr->id = acpi_map_cpuid(pr->phys_id, pr->acpi_id);
283         if (!cpu0_initialized && !acpi_has_cpu_in_madt()) {
284                 cpu0_initialized = 1;
285                 /*
286                  * Handle UP system running SMP kernel, with no CPU
287                  * entry in MADT
288                  */
289                 if (invalid_logical_cpuid(pr->id) && (num_online_cpus() == 1))
290                         pr->id = 0;
291         }
292
293         /*
294          *  Extra Processor objects may be enumerated on MP systems with
295          *  less than the max # of CPUs. They should be ignored _iff
296          *  they are physically not present.
297          *
298          *  NOTE: Even if the processor has a cpuid, it may not be present
299          *  because cpuid <-> apicid mapping is persistent now.
300          */
301         if (invalid_logical_cpuid(pr->id) || !cpu_present(pr->id)) {
302                 int ret = acpi_processor_hotadd_init(pr);
303
304                 if (ret)
305                         return ret;
306         }
307
308         /*
309          * On some boxes several processors use the same processor bus id.
310          * But they are located in different scope. For example:
311          * \_SB.SCK0.CPU0
312          * \_SB.SCK1.CPU0
313          * Rename the processor device bus id. And the new bus id will be
314          * generated as the following format:
315          * CPU+CPU ID.
316          */
317         sprintf(acpi_device_bid(device), "CPU%X", pr->id);
318         dev_dbg(&device->dev, "Processor [%d:%d]\n", pr->id, pr->acpi_id);
319
320         if (!object.processor.pblk_address)
321                 dev_dbg(&device->dev, "No PBLK (NULL address)\n");
322         else if (object.processor.pblk_length != 6)
323                 dev_err(&device->dev, "Invalid PBLK length [%d]\n",
324                             object.processor.pblk_length);
325         else {
326                 pr->throttling.address = object.processor.pblk_address;
327                 pr->throttling.duty_offset = acpi_gbl_FADT.duty_offset;
328                 pr->throttling.duty_width = acpi_gbl_FADT.duty_width;
329
330                 pr->pblk = object.processor.pblk_address;
331         }
332
333         /*
334          * If ACPI describes a slot number for this CPU, we can use it to
335          * ensure we get the right value in the "physical id" field
336          * of /proc/cpuinfo
337          */
338         status = acpi_evaluate_integer(pr->handle, "_SUN", NULL, &value);
339         if (ACPI_SUCCESS(status))
340                 arch_fix_phys_package_id(pr->id, value);
341
342         return 0;
343 }
344
345 /*
346  * Do not put anything in here which needs the core to be online.
347  * For example MSR access or setting up things which check for cpuinfo_x86
348  * (cpu_data(cpu)) values, like CPU feature flags, family, model, etc.
349  * Such things have to be put in and set up by the processor driver's .probe().
350  */
351 static DEFINE_PER_CPU(void *, processor_device_array);
352
353 static int acpi_processor_add(struct acpi_device *device,
354                                         const struct acpi_device_id *id)
355 {
356         struct acpi_processor *pr;
357         struct device *dev;
358         int result = 0;
359
360         pr = kzalloc(sizeof(struct acpi_processor), GFP_KERNEL);
361         if (!pr)
362                 return -ENOMEM;
363
364         if (!zalloc_cpumask_var(&pr->throttling.shared_cpu_map, GFP_KERNEL)) {
365                 result = -ENOMEM;
366                 goto err_free_pr;
367         }
368
369         pr->handle = device->handle;
370         strcpy(acpi_device_name(device), ACPI_PROCESSOR_DEVICE_NAME);
371         strcpy(acpi_device_class(device), ACPI_PROCESSOR_CLASS);
372         device->driver_data = pr;
373
374         result = acpi_processor_get_info(device);
375         if (result) /* Processor is not physically present or unavailable */
376                 return 0;
377
378         BUG_ON(pr->id >= nr_cpu_ids);
379
380         /*
381          * Buggy BIOS check.
382          * ACPI id of processors can be reported wrongly by the BIOS.
383          * Don't trust it blindly
384          */
385         if (per_cpu(processor_device_array, pr->id) != NULL &&
386             per_cpu(processor_device_array, pr->id) != device) {
387                 dev_warn(&device->dev,
388                         "BIOS reported wrong ACPI id %d for the processor\n",
389                         pr->id);
390                 /* Give up, but do not abort the namespace scan. */
391                 goto err;
392         }
393         /*
394          * processor_device_array is not cleared on errors to allow buggy BIOS
395          * checks.
396          */
397         per_cpu(processor_device_array, pr->id) = device;
398         per_cpu(processors, pr->id) = pr;
399
400         dev = get_cpu_device(pr->id);
401         if (!dev) {
402                 result = -ENODEV;
403                 goto err;
404         }
405
406         result = acpi_bind_one(dev, device);
407         if (result)
408                 goto err;
409
410         pr->dev = dev;
411
412         /* Trigger the processor driver's .probe() if present. */
413         if (device_attach(dev) >= 0)
414                 return 1;
415
416         dev_err(dev, "Processor driver could not be attached\n");
417         acpi_unbind_one(dev);
418
419  err:
420         free_cpumask_var(pr->throttling.shared_cpu_map);
421         device->driver_data = NULL;
422         per_cpu(processors, pr->id) = NULL;
423  err_free_pr:
424         kfree(pr);
425         return result;
426 }
427
428 #ifdef CONFIG_ACPI_HOTPLUG_CPU
429 /* Removal */
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_cpu(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 #ifdef CONFIG_X86
475 static bool acpi_hwp_native_thermal_lvt_set;
476 static acpi_status __init acpi_hwp_native_thermal_lvt_osc(acpi_handle handle,
477                                                           u32 lvl,
478                                                           void *context,
479                                                           void **rv)
480 {
481         u8 sb_uuid_str[] = "4077A616-290C-47BE-9EBD-D87058713953";
482         u32 capbuf[2];
483         struct acpi_osc_context osc_context = {
484                 .uuid_str = sb_uuid_str,
485                 .rev = 1,
486                 .cap.length = 8,
487                 .cap.pointer = capbuf,
488         };
489
490         if (acpi_hwp_native_thermal_lvt_set)
491                 return AE_CTRL_TERMINATE;
492
493         capbuf[0] = 0x0000;
494         capbuf[1] = 0x1000; /* set bit 12 */
495
496         if (ACPI_SUCCESS(acpi_run_osc(handle, &osc_context))) {
497                 if (osc_context.ret.pointer && osc_context.ret.length > 1) {
498                         u32 *capbuf_ret = osc_context.ret.pointer;
499
500                         if (capbuf_ret[1] & 0x1000) {
501                                 acpi_handle_info(handle,
502                                         "_OSC native thermal LVT Acked\n");
503                                 acpi_hwp_native_thermal_lvt_set = true;
504                         }
505                 }
506                 kfree(osc_context.ret.pointer);
507         }
508
509         return AE_OK;
510 }
511
512 void __init acpi_early_processor_osc(void)
513 {
514         if (boot_cpu_has(X86_FEATURE_HWP)) {
515                 acpi_walk_namespace(ACPI_TYPE_PROCESSOR, ACPI_ROOT_OBJECT,
516                                     ACPI_UINT32_MAX,
517                                     acpi_hwp_native_thermal_lvt_osc,
518                                     NULL, NULL, NULL);
519                 acpi_get_devices(ACPI_PROCESSOR_DEVICE_HID,
520                                  acpi_hwp_native_thermal_lvt_osc,
521                                  NULL, NULL);
522         }
523 }
524 #endif
525
526 /*
527  * The following ACPI IDs are known to be suitable for representing as
528  * processor devices.
529  */
530 static const struct acpi_device_id processor_device_ids[] = {
531
532         { ACPI_PROCESSOR_OBJECT_HID, },
533         { ACPI_PROCESSOR_DEVICE_HID, },
534
535         { }
536 };
537
538 static struct acpi_scan_handler processor_handler = {
539         .ids = processor_device_ids,
540         .attach = acpi_processor_add,
541 #ifdef CONFIG_ACPI_HOTPLUG_CPU
542         .detach = acpi_processor_remove,
543 #endif
544         .hotplug = {
545                 .enabled = true,
546         },
547 };
548
549 static int acpi_processor_container_attach(struct acpi_device *dev,
550                                            const struct acpi_device_id *id)
551 {
552         return 1;
553 }
554
555 static const struct acpi_device_id processor_container_ids[] = {
556         { ACPI_PROCESSOR_CONTAINER_HID, },
557         { }
558 };
559
560 static struct acpi_scan_handler processor_container_handler = {
561         .ids = processor_container_ids,
562         .attach = acpi_processor_container_attach,
563 };
564
565 /* The number of the unique processor IDs */
566 static int nr_unique_ids __initdata;
567
568 /* The number of the duplicate processor IDs */
569 static int nr_duplicate_ids;
570
571 /* Used to store the unique processor IDs */
572 static int unique_processor_ids[] __initdata = {
573         [0 ... NR_CPUS - 1] = -1,
574 };
575
576 /* Used to store the duplicate processor IDs */
577 static int duplicate_processor_ids[] = {
578         [0 ... NR_CPUS - 1] = -1,
579 };
580
581 static void __init processor_validated_ids_update(int proc_id)
582 {
583         int i;
584
585         if (nr_unique_ids == NR_CPUS||nr_duplicate_ids == NR_CPUS)
586                 return;
587
588         /*
589          * Firstly, compare the proc_id with duplicate IDs, if the proc_id is
590          * already in the IDs, do nothing.
591          */
592         for (i = 0; i < nr_duplicate_ids; i++) {
593                 if (duplicate_processor_ids[i] == proc_id)
594                         return;
595         }
596
597         /*
598          * Secondly, compare the proc_id with unique IDs, if the proc_id is in
599          * the IDs, put it in the duplicate IDs.
600          */
601         for (i = 0; i < nr_unique_ids; i++) {
602                 if (unique_processor_ids[i] == proc_id) {
603                         duplicate_processor_ids[nr_duplicate_ids] = proc_id;
604                         nr_duplicate_ids++;
605                         return;
606                 }
607         }
608
609         /*
610          * Lastly, the proc_id is a unique ID, put it in the unique IDs.
611          */
612         unique_processor_ids[nr_unique_ids] = proc_id;
613         nr_unique_ids++;
614 }
615
616 static acpi_status __init acpi_processor_ids_walk(acpi_handle handle,
617                                                   u32 lvl,
618                                                   void *context,
619                                                   void **rv)
620 {
621         acpi_status status;
622         acpi_object_type acpi_type;
623         unsigned long long uid;
624         union acpi_object object = { 0 };
625         struct acpi_buffer buffer = { sizeof(union acpi_object), &object };
626
627         status = acpi_get_type(handle, &acpi_type);
628         if (ACPI_FAILURE(status))
629                 return status;
630
631         switch (acpi_type) {
632         case ACPI_TYPE_PROCESSOR:
633                 status = acpi_evaluate_object(handle, NULL, NULL, &buffer);
634                 if (ACPI_FAILURE(status))
635                         goto err;
636                 uid = object.processor.proc_id;
637                 break;
638
639         case ACPI_TYPE_DEVICE:
640                 status = acpi_evaluate_integer(handle, "_UID", NULL, &uid);
641                 if (ACPI_FAILURE(status))
642                         goto err;
643                 break;
644         default:
645                 goto err;
646         }
647
648         processor_validated_ids_update(uid);
649         return AE_OK;
650
651 err:
652         /* Exit on error, but don't abort the namespace walk */
653         acpi_handle_info(handle, "Invalid processor object\n");
654         return AE_OK;
655
656 }
657
658 static void __init acpi_processor_check_duplicates(void)
659 {
660         /* check the correctness for all processors in ACPI namespace */
661         acpi_walk_namespace(ACPI_TYPE_PROCESSOR, ACPI_ROOT_OBJECT,
662                                                 ACPI_UINT32_MAX,
663                                                 acpi_processor_ids_walk,
664                                                 NULL, NULL, NULL);
665         acpi_get_devices(ACPI_PROCESSOR_DEVICE_HID, acpi_processor_ids_walk,
666                                                 NULL, NULL);
667 }
668
669 bool acpi_duplicate_processor_id(int proc_id)
670 {
671         int i;
672
673         /*
674          * compare the proc_id with duplicate IDs, if the proc_id is already
675          * in the duplicate IDs, return true, otherwise, return false.
676          */
677         for (i = 0; i < nr_duplicate_ids; i++) {
678                 if (duplicate_processor_ids[i] == proc_id)
679                         return true;
680         }
681         return false;
682 }
683
684 void __init acpi_processor_init(void)
685 {
686         acpi_processor_check_duplicates();
687         acpi_scan_add_handler_with_hotplug(&processor_handler, "processor");
688         acpi_scan_add_handler(&processor_container_handler);
689 }
690
691 #ifdef CONFIG_ACPI_PROCESSOR_CSTATE
692 /**
693  * acpi_processor_claim_cst_control - Request _CST control from the platform.
694  */
695 bool acpi_processor_claim_cst_control(void)
696 {
697         static bool cst_control_claimed;
698         acpi_status status;
699
700         if (!acpi_gbl_FADT.cst_control || cst_control_claimed)
701                 return true;
702
703         status = acpi_os_write_port(acpi_gbl_FADT.smi_command,
704                                     acpi_gbl_FADT.cst_control, 8);
705         if (ACPI_FAILURE(status)) {
706                 pr_warn("ACPI: Failed to claim processor _CST control\n");
707                 return false;
708         }
709
710         cst_control_claimed = true;
711         return true;
712 }
713 EXPORT_SYMBOL_GPL(acpi_processor_claim_cst_control);
714
715 /**
716  * acpi_processor_evaluate_cst - Evaluate the processor _CST control method.
717  * @handle: ACPI handle of the processor object containing the _CST.
718  * @cpu: The numeric ID of the target CPU.
719  * @info: Object write the C-states information into.
720  *
721  * Extract the C-state information for the given CPU from the output of the _CST
722  * control method under the corresponding ACPI processor object (or processor
723  * device object) and populate @info with it.
724  *
725  * If any ACPI_ADR_SPACE_FIXED_HARDWARE C-states are found, invoke
726  * acpi_processor_ffh_cstate_probe() to verify them and update the
727  * cpu_cstate_entry data for @cpu.
728  */
729 int acpi_processor_evaluate_cst(acpi_handle handle, u32 cpu,
730                                 struct acpi_processor_power *info)
731 {
732         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
733         union acpi_object *cst;
734         acpi_status status;
735         u64 count;
736         int last_index = 0;
737         int i, ret = 0;
738
739         status = acpi_evaluate_object(handle, "_CST", NULL, &buffer);
740         if (ACPI_FAILURE(status)) {
741                 acpi_handle_debug(handle, "No _CST\n");
742                 return -ENODEV;
743         }
744
745         cst = buffer.pointer;
746
747         /* There must be at least 2 elements. */
748         if (!cst || cst->type != ACPI_TYPE_PACKAGE || cst->package.count < 2) {
749                 acpi_handle_warn(handle, "Invalid _CST output\n");
750                 ret = -EFAULT;
751                 goto end;
752         }
753
754         count = cst->package.elements[0].integer.value;
755
756         /* Validate the number of C-states. */
757         if (count < 1 || count != cst->package.count - 1) {
758                 acpi_handle_warn(handle, "Inconsistent _CST data\n");
759                 ret = -EFAULT;
760                 goto end;
761         }
762
763         for (i = 1; i <= count; i++) {
764                 union acpi_object *element;
765                 union acpi_object *obj;
766                 struct acpi_power_register *reg;
767                 struct acpi_processor_cx cx;
768
769                 /*
770                  * If there is not enough space for all C-states, skip the
771                  * excess ones and log a warning.
772                  */
773                 if (last_index >= ACPI_PROCESSOR_MAX_POWER - 1) {
774                         acpi_handle_warn(handle,
775                                          "No room for more idle states (limit: %d)\n",
776                                          ACPI_PROCESSOR_MAX_POWER - 1);
777                         break;
778                 }
779
780                 memset(&cx, 0, sizeof(cx));
781
782                 element = &cst->package.elements[i];
783                 if (element->type != ACPI_TYPE_PACKAGE) {
784                         acpi_handle_info(handle, "_CST C%d type(%x) is not package, skip...\n",
785                                          i, element->type);
786                         continue;
787                 }
788
789                 if (element->package.count != 4) {
790                         acpi_handle_info(handle, "_CST C%d package count(%d) is not 4, skip...\n",
791                                          i, element->package.count);
792                         continue;
793                 }
794
795                 obj = &element->package.elements[0];
796
797                 if (obj->type != ACPI_TYPE_BUFFER) {
798                         acpi_handle_info(handle, "_CST C%d package element[0] type(%x) is not buffer, skip...\n",
799                                          i, obj->type);
800                         continue;
801                 }
802
803                 reg = (struct acpi_power_register *)obj->buffer.pointer;
804
805                 obj = &element->package.elements[1];
806                 if (obj->type != ACPI_TYPE_INTEGER) {
807                         acpi_handle_info(handle, "_CST C[%d] package element[1] type(%x) is not integer, skip...\n",
808                                          i, obj->type);
809                         continue;
810                 }
811
812                 cx.type = obj->integer.value;
813                 /*
814                  * There are known cases in which the _CST output does not
815                  * contain C1, so if the type of the first state found is not
816                  * C1, leave an empty slot for C1 to be filled in later.
817                  */
818                 if (i == 1 && cx.type != ACPI_STATE_C1)
819                         last_index = 1;
820
821                 cx.address = reg->address;
822                 cx.index = last_index + 1;
823
824                 if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) {
825                         if (!acpi_processor_ffh_cstate_probe(cpu, &cx, reg)) {
826                                 /*
827                                  * In the majority of cases _CST describes C1 as
828                                  * a FIXED_HARDWARE C-state, but if the command
829                                  * line forbids using MWAIT, use CSTATE_HALT for
830                                  * C1 regardless.
831                                  */
832                                 if (cx.type == ACPI_STATE_C1 &&
833                                     boot_option_idle_override == IDLE_NOMWAIT) {
834                                         cx.entry_method = ACPI_CSTATE_HALT;
835                                         snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
836                                 } else {
837                                         cx.entry_method = ACPI_CSTATE_FFH;
838                                 }
839                         } else if (cx.type == ACPI_STATE_C1) {
840                                 /*
841                                  * In the special case of C1, FIXED_HARDWARE can
842                                  * be handled by executing the HLT instruction.
843                                  */
844                                 cx.entry_method = ACPI_CSTATE_HALT;
845                                 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
846                         } else {
847                                 acpi_handle_info(handle, "_CST C%d declares FIXED_HARDWARE C-state but not supported in hardware, skip...\n",
848                                                  i);
849                                 continue;
850                         }
851                 } else if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_IO) {
852                         cx.entry_method = ACPI_CSTATE_SYSTEMIO;
853                         snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI IOPORT 0x%x",
854                                  cx.address);
855                 } else {
856                         acpi_handle_info(handle, "_CST C%d space_id(%x) neither FIXED_HARDWARE nor SYSTEM_IO, skip...\n",
857                                          i, reg->space_id);
858                         continue;
859                 }
860
861                 if (cx.type == ACPI_STATE_C1)
862                         cx.valid = 1;
863
864                 obj = &element->package.elements[2];
865                 if (obj->type != ACPI_TYPE_INTEGER) {
866                         acpi_handle_info(handle, "_CST C%d package element[2] type(%x) not integer, skip...\n",
867                                          i, obj->type);
868                         continue;
869                 }
870
871                 cx.latency = obj->integer.value;
872
873                 obj = &element->package.elements[3];
874                 if (obj->type != ACPI_TYPE_INTEGER) {
875                         acpi_handle_info(handle, "_CST C%d package element[3] type(%x) not integer, skip...\n",
876                                          i, obj->type);
877                         continue;
878                 }
879
880                 memcpy(&info->states[++last_index], &cx, sizeof(cx));
881         }
882
883         acpi_handle_info(handle, "Found %d idle states\n", last_index);
884
885         info->count = last_index;
886
887 end:
888         kfree(buffer.pointer);
889
890         return ret;
891 }
892 EXPORT_SYMBOL_GPL(acpi_processor_evaluate_cst);
893 #endif /* CONFIG_ACPI_PROCESSOR_CSTATE */