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Linux/drivers/acpi/acpi_processor.c

  1 /*
  2  * acpi_processor.c - ACPI processor enumeration support
  3  *
  4  * Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
  5  * Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
  6  * Copyright (C) 2004       Dominik Brodowski <linux@brodo.de>
  7  * Copyright (C) 2004  Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
  8  * Copyright (C) 2013, Intel Corporation
  9  *                     Rafael J. Wysocki <rafael.j.wysocki@intel.com>
 10  *
 11  * This program is free software; you can redistribute it and/or modify it
 12  * under the terms of the GNU General Public License version 2 as published
 13  * by the Free Software Foundation.
 14  */
 15 
 16 #include <linux/acpi.h>
 17 #include <linux/device.h>
 18 #include <linux/kernel.h>
 19 #include <linux/module.h>
 20 #include <linux/pci.h>
 21 
 22 #include <acpi/processor.h>
 23 
 24 #include <asm/cpu.h>
 25 
 26 #include "internal.h"
 27 
 28 #define _COMPONENT      ACPI_PROCESSOR_COMPONENT
 29 
 30 ACPI_MODULE_NAME("processor");
 31 
 32 DEFINE_PER_CPU(struct acpi_processor *, processors);
 33 EXPORT_PER_CPU_SYMBOL(processors);
 34 
 35 /* --------------------------------------------------------------------------
 36                                 Errata Handling
 37    -------------------------------------------------------------------------- */
 38 
 39 struct acpi_processor_errata errata __read_mostly;
 40 EXPORT_SYMBOL_GPL(errata);
 41 
 42 static int acpi_processor_errata_piix4(struct pci_dev *dev)
 43 {
 44         u8 value1 = 0;
 45         u8 value2 = 0;
 46 
 47 
 48         if (!dev)
 49                 return -EINVAL;
 50 
 51         /*
 52          * Note that 'dev' references the PIIX4 ACPI Controller.
 53          */
 54 
 55         switch (dev->revision) {
 56         case 0:
 57                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found PIIX4 A-step\n"));
 58                 break;
 59         case 1:
 60                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found PIIX4 B-step\n"));
 61                 break;
 62         case 2:
 63                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found PIIX4E\n"));
 64                 break;
 65         case 3:
 66                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found PIIX4M\n"));
 67                 break;
 68         default:
 69                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found unknown PIIX4\n"));
 70                 break;
 71         }
 72 
 73         switch (dev->revision) {
 74 
 75         case 0:         /* PIIX4 A-step */
 76         case 1:         /* PIIX4 B-step */
 77                 /*
 78                  * See specification changes #13 ("Manual Throttle Duty Cycle")
 79                  * and #14 ("Enabling and Disabling Manual Throttle"), plus
 80                  * erratum #5 ("STPCLK# Deassertion Time") from the January
 81                  * 2002 PIIX4 specification update.  Applies to only older
 82                  * PIIX4 models.
 83                  */
 84                 errata.piix4.throttle = 1;
 85 
 86         case 2:         /* PIIX4E */
 87         case 3:         /* PIIX4M */
 88                 /*
 89                  * See erratum #18 ("C3 Power State/BMIDE and Type-F DMA
 90                  * Livelock") from the January 2002 PIIX4 specification update.
 91                  * Applies to all PIIX4 models.
 92                  */
 93 
 94                 /*
 95                  * BM-IDE
 96                  * ------
 97                  * Find the PIIX4 IDE Controller and get the Bus Master IDE
 98                  * Status register address.  We'll use this later to read
 99                  * each IDE controller's DMA status to make sure we catch all
100                  * DMA activity.
101                  */
102                 dev = pci_get_subsys(PCI_VENDOR_ID_INTEL,
103                                      PCI_DEVICE_ID_INTEL_82371AB,
104                                      PCI_ANY_ID, PCI_ANY_ID, NULL);
105                 if (dev) {
106                         errata.piix4.bmisx = pci_resource_start(dev, 4);
107                         pci_dev_put(dev);
108                 }
109 
110                 /*
111                  * Type-F DMA
112                  * ----------
113                  * Find the PIIX4 ISA Controller and read the Motherboard
114                  * DMA controller's status to see if Type-F (Fast) DMA mode
115                  * is enabled (bit 7) on either channel.  Note that we'll
116                  * disable C3 support if this is enabled, as some legacy
117                  * devices won't operate well if fast DMA is disabled.
118                  */
119                 dev = pci_get_subsys(PCI_VENDOR_ID_INTEL,
120                                      PCI_DEVICE_ID_INTEL_82371AB_0,
121                                      PCI_ANY_ID, PCI_ANY_ID, NULL);
122                 if (dev) {
123                         pci_read_config_byte(dev, 0x76, &value1);
124                         pci_read_config_byte(dev, 0x77, &value2);
125                         if ((value1 & 0x80) || (value2 & 0x80))
126                                 errata.piix4.fdma = 1;
127                         pci_dev_put(dev);
128                 }
129 
130                 break;
131         }
132 
133         if (errata.piix4.bmisx)
134                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
135                                   "Bus master activity detection (BM-IDE) erratum enabled\n"));
136         if (errata.piix4.fdma)
137                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
138                                   "Type-F DMA livelock erratum (C3 disabled)\n"));
139 
140         return 0;
141 }
142 
143 static int acpi_processor_errata(void)
144 {
145         int result = 0;
146         struct pci_dev *dev = NULL;
147 
148         /*
149          * PIIX4
150          */
151         dev = pci_get_subsys(PCI_VENDOR_ID_INTEL,
152                              PCI_DEVICE_ID_INTEL_82371AB_3, PCI_ANY_ID,
153                              PCI_ANY_ID, NULL);
154         if (dev) {
155                 result = acpi_processor_errata_piix4(dev);
156                 pci_dev_put(dev);
157         }
158 
159         return result;
160 }
161 
162 /* --------------------------------------------------------------------------
163                                 Initialization
164    -------------------------------------------------------------------------- */
165 
166 #ifdef CONFIG_ACPI_HOTPLUG_CPU
167 static int acpi_processor_hotadd_init(struct acpi_processor *pr)
168 {
169         unsigned long long sta;
170         acpi_status status;
171         int ret;
172 
173         if (pr->apic_id == -1)
174                 return -ENODEV;
175 
176         status = acpi_evaluate_integer(pr->handle, "_STA", NULL, &sta);
177         if (ACPI_FAILURE(status) || !(sta & ACPI_STA_DEVICE_PRESENT))
178                 return -ENODEV;
179 
180         cpu_maps_update_begin();
181         cpu_hotplug_begin();
182 
183         ret = acpi_map_lsapic(pr->handle, pr->apic_id, &pr->id);
184         if (ret)
185                 goto out;
186 
187         ret = arch_register_cpu(pr->id);
188         if (ret) {
189                 acpi_unmap_lsapic(pr->id);
190                 goto out;
191         }
192 
193         /*
194          * CPU got hot-added, but cpu_data is not initialized yet.  Set a flag
195          * to delay cpu_idle/throttling initialization and do it when the CPU
196          * gets online for the first time.
197          */
198         pr_info("CPU%d has been hot-added\n", pr->id);
199         pr->flags.need_hotplug_init = 1;
200 
201 out:
202         cpu_hotplug_done();
203         cpu_maps_update_done();
204         return ret;
205 }
206 #else
207 static inline int acpi_processor_hotadd_init(struct acpi_processor *pr)
208 {
209         return -ENODEV;
210 }
211 #endif /* CONFIG_ACPI_HOTPLUG_CPU */
212 
213 static int acpi_processor_get_info(struct acpi_device *device)
214 {
215         union acpi_object object = { 0 };
216         struct acpi_buffer buffer = { sizeof(union acpi_object), &object };
217         struct acpi_processor *pr = acpi_driver_data(device);
218         int apic_id, cpu_index, device_declaration = 0;
219         acpi_status status = AE_OK;
220         static int cpu0_initialized;
221         unsigned long long value;
222 
223         acpi_processor_errata();
224 
225         /*
226          * Check to see if we have bus mastering arbitration control.  This
227          * is required for proper C3 usage (to maintain cache coherency).
228          */
229         if (acpi_gbl_FADT.pm2_control_block && acpi_gbl_FADT.pm2_control_length) {
230                 pr->flags.bm_control = 1;
231                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
232                                   "Bus mastering arbitration control present\n"));
233         } else
234                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
235                                   "No bus mastering arbitration control\n"));
236 
237         if (!strcmp(acpi_device_hid(device), ACPI_PROCESSOR_OBJECT_HID)) {
238                 /* Declared with "Processor" statement; match ProcessorID */
239                 status = acpi_evaluate_object(pr->handle, NULL, NULL, &buffer);
240                 if (ACPI_FAILURE(status)) {
241                         dev_err(&device->dev,
242                                 "Failed to evaluate processor object (0x%x)\n",
243                                 status);
244                         return -ENODEV;
245                 }
246 
247                 pr->acpi_id = object.processor.proc_id;
248         } else {
249                 /*
250                  * Declared with "Device" statement; match _UID.
251                  * Note that we don't handle string _UIDs yet.
252                  */
253                 status = acpi_evaluate_integer(pr->handle, METHOD_NAME__UID,
254                                                 NULL, &value);
255                 if (ACPI_FAILURE(status)) {
256                         dev_err(&device->dev,
257                                 "Failed to evaluate processor _UID (0x%x)\n",
258                                 status);
259                         return -ENODEV;
260                 }
261                 device_declaration = 1;
262                 pr->acpi_id = value;
263         }
264 
265         apic_id = acpi_get_apicid(pr->handle, device_declaration, pr->acpi_id);
266         if (apic_id < 0)
267                 acpi_handle_debug(pr->handle, "failed to get CPU APIC ID.\n");
268         pr->apic_id = apic_id;
269 
270         cpu_index = acpi_map_cpuid(pr->apic_id, pr->acpi_id);
271         if (!cpu0_initialized) {
272                 cpu0_initialized = 1;
273                 /* Handle UP system running SMP kernel, with no LAPIC in MADT */
274                 if ((cpu_index == -1) && (num_online_cpus() == 1))
275                         cpu_index = 0;
276         }
277         pr->id = cpu_index;
278 
279         /*
280          *  Extra Processor objects may be enumerated on MP systems with
281          *  less than the max # of CPUs. They should be ignored _iff
282          *  they are physically not present.
283          */
284         if (pr->id == -1) {
285                 int ret = acpi_processor_hotadd_init(pr);
286                 if (ret)
287                         return ret;
288         }
289 
290         /*
291          * On some boxes several processors use the same processor bus id.
292          * But they are located in different scope. For example:
293          * \_SB.SCK0.CPU0
294          * \_SB.SCK1.CPU0
295          * Rename the processor device bus id. And the new bus id will be
296          * generated as the following format:
297          * CPU+CPU ID.
298          */
299         sprintf(acpi_device_bid(device), "CPU%X", pr->id);
300         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Processor [%d:%d]\n", pr->id,
301                           pr->acpi_id));
302 
303         if (!object.processor.pblk_address)
304                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No PBLK (NULL address)\n"));
305         else if (object.processor.pblk_length != 6)
306                 dev_err(&device->dev, "Invalid PBLK length [%d]\n",
307                             object.processor.pblk_length);
308         else {
309                 pr->throttling.address = object.processor.pblk_address;
310                 pr->throttling.duty_offset = acpi_gbl_FADT.duty_offset;
311                 pr->throttling.duty_width = acpi_gbl_FADT.duty_width;
312 
313                 pr->pblk = object.processor.pblk_address;
314 
315                 /*
316                  * We don't care about error returns - we just try to mark
317                  * these reserved so that nobody else is confused into thinking
318                  * that this region might be unused..
319                  *
320                  * (In particular, allocating the IO range for Cardbus)
321                  */
322                 request_region(pr->throttling.address, 6, "ACPI CPU throttle");
323         }
324 
325         /*
326          * If ACPI describes a slot number for this CPU, we can use it to
327          * ensure we get the right value in the "physical id" field
328          * of /proc/cpuinfo
329          */
330         status = acpi_evaluate_integer(pr->handle, "_SUN", NULL, &value);
331         if (ACPI_SUCCESS(status))
332                 arch_fix_phys_package_id(pr->id, value);
333 
334         return 0;
335 }
336 
337 /*
338  * Do not put anything in here which needs the core to be online.
339  * For example MSR access or setting up things which check for cpuinfo_x86
340  * (cpu_data(cpu)) values, like CPU feature flags, family, model, etc.
341  * Such things have to be put in and set up by the processor driver's .probe().
342  */
343 static DEFINE_PER_CPU(void *, processor_device_array);
344 
345 static int acpi_processor_add(struct acpi_device *device,
346                                         const struct acpi_device_id *id)
347 {
348         struct acpi_processor *pr;
349         struct device *dev;
350         int result = 0;
351 
352         pr = kzalloc(sizeof(struct acpi_processor), GFP_KERNEL);
353         if (!pr)
354                 return -ENOMEM;
355 
356         if (!zalloc_cpumask_var(&pr->throttling.shared_cpu_map, GFP_KERNEL)) {
357                 result = -ENOMEM;
358                 goto err_free_pr;
359         }
360 
361         pr->handle = device->handle;
362         strcpy(acpi_device_name(device), ACPI_PROCESSOR_DEVICE_NAME);
363         strcpy(acpi_device_class(device), ACPI_PROCESSOR_CLASS);
364         device->driver_data = pr;
365 
366         result = acpi_processor_get_info(device);
367         if (result) /* Processor is not physically present or unavailable */
368                 return 0;
369 
370 #ifdef CONFIG_SMP
371         if (pr->id >= setup_max_cpus && pr->id != 0)
372                 return 0;
373 #endif
374 
375         BUG_ON(pr->id >= nr_cpu_ids);
376 
377         /*
378          * Buggy BIOS check.
379          * ACPI id of processors can be reported wrongly by the BIOS.
380          * Don't trust it blindly
381          */
382         if (per_cpu(processor_device_array, pr->id) != NULL &&
383             per_cpu(processor_device_array, pr->id) != device) {
384                 dev_warn(&device->dev,
385                         "BIOS reported wrong ACPI id %d for the processor\n",
386                         pr->id);
387                 /* Give up, but do not abort the namespace scan. */
388                 goto err;
389         }
390         /*
391          * processor_device_array is not cleared on errors to allow buggy BIOS
392          * checks.
393          */
394         per_cpu(processor_device_array, pr->id) = device;
395         per_cpu(processors, pr->id) = pr;
396 
397         dev = get_cpu_device(pr->id);
398         if (!dev) {
399                 result = -ENODEV;
400                 goto err;
401         }
402 
403         result = acpi_bind_one(dev, device);
404         if (result)
405                 goto err;
406 
407         pr->dev = dev;
408 
409         /* Trigger the processor driver's .probe() if present. */
410         if (device_attach(dev) >= 0)
411                 return 1;
412 
413         dev_err(dev, "Processor driver could not be attached\n");
414         acpi_unbind_one(dev);
415 
416  err:
417         free_cpumask_var(pr->throttling.shared_cpu_map);
418         device->driver_data = NULL;
419         per_cpu(processors, pr->id) = NULL;
420  err_free_pr:
421         kfree(pr);
422         return result;
423 }
424 
425 #ifdef CONFIG_ACPI_HOTPLUG_CPU
426 /* --------------------------------------------------------------------------
427                                     Removal
428    -------------------------------------------------------------------------- */
429 
430 static void acpi_processor_remove(struct acpi_device *device)
431 {
432         struct acpi_processor *pr;
433 
434         if (!device || !acpi_driver_data(device))
435                 return;
436 
437         pr = acpi_driver_data(device);
438         if (pr->id >= nr_cpu_ids)
439                 goto out;
440 
441         /*
442          * The only reason why we ever get here is CPU hot-removal.  The CPU is
443          * already offline and the ACPI device removal locking prevents it from
444          * being put back online at this point.
445          *
446          * Unbind the driver from the processor device and detach it from the
447          * ACPI companion object.
448          */
449         device_release_driver(pr->dev);
450         acpi_unbind_one(pr->dev);
451 
452         /* Clean up. */
453         per_cpu(processor_device_array, pr->id) = NULL;
454         per_cpu(processors, pr->id) = NULL;
455 
456         cpu_maps_update_begin();
457         cpu_hotplug_begin();
458 
459         /* Remove the CPU. */
460         arch_unregister_cpu(pr->id);
461         acpi_unmap_lsapic(pr->id);
462 
463         cpu_hotplug_done();
464         cpu_maps_update_done();
465 
466         try_offline_node(cpu_to_node(pr->id));
467 
468  out:
469         free_cpumask_var(pr->throttling.shared_cpu_map);
470         kfree(pr);
471 }
472 #endif /* CONFIG_ACPI_HOTPLUG_CPU */
473 
474 /*
475  * The following ACPI IDs are known to be suitable for representing as
476  * processor devices.
477  */
478 static const struct acpi_device_id processor_device_ids[] = {
479 
480         { ACPI_PROCESSOR_OBJECT_HID, },
481         { ACPI_PROCESSOR_DEVICE_HID, },
482 
483         { }
484 };
485 
486 static struct acpi_scan_handler __refdata processor_handler = {
487         .ids = processor_device_ids,
488         .attach = acpi_processor_add,
489 #ifdef CONFIG_ACPI_HOTPLUG_CPU
490         .detach = acpi_processor_remove,
491 #endif
492         .hotplug = {
493                 .enabled = true,
494         },
495 };
496 
497 void __init acpi_processor_init(void)
498 {
499         acpi_scan_add_handler_with_hotplug(&processor_handler, "processor");
500 }
501 

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