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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->phys_id == PHYS_CPUID_INVALID)
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_cpu(pr->handle, pr->phys_id, &pr->id);
184         if (ret)
185                 goto out;
186 
187         ret = arch_register_cpu(pr->id);
188         if (ret) {
189                 acpi_unmap_cpu(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         phys_cpuid_t phys_id;
219         int cpu_index, device_declaration = 0;
220         acpi_status status = AE_OK;
221         static int cpu0_initialized;
222         unsigned long long value;
223 
224         acpi_processor_errata();
225 
226         /*
227          * Check to see if we have bus mastering arbitration control.  This
228          * is required for proper C3 usage (to maintain cache coherency).
229          */
230         if (acpi_gbl_FADT.pm2_control_block && acpi_gbl_FADT.pm2_control_length) {
231                 pr->flags.bm_control = 1;
232                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
233                                   "Bus mastering arbitration control present\n"));
234         } else
235                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
236                                   "No bus mastering arbitration control\n"));
237 
238         if (!strcmp(acpi_device_hid(device), ACPI_PROCESSOR_OBJECT_HID)) {
239                 /* Declared with "Processor" statement; match ProcessorID */
240                 status = acpi_evaluate_object(pr->handle, NULL, NULL, &buffer);
241                 if (ACPI_FAILURE(status)) {
242                         dev_err(&device->dev,
243                                 "Failed to evaluate processor object (0x%x)\n",
244                                 status);
245                         return -ENODEV;
246                 }
247 
248                 pr->acpi_id = object.processor.proc_id;
249         } else {
250                 /*
251                  * Declared with "Device" statement; match _UID.
252                  * Note that we don't handle string _UIDs yet.
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         phys_id = acpi_get_phys_id(pr->handle, device_declaration, pr->acpi_id);
267         if (phys_id == PHYS_CPUID_INVALID)
268                 acpi_handle_debug(pr->handle, "failed to get CPU physical ID.\n");
269         pr->phys_id = phys_id;
270 
271         cpu_index = acpi_map_cpuid(pr->phys_id, pr->acpi_id);
272         if (!cpu0_initialized && !acpi_has_cpu_in_madt()) {
273                 cpu0_initialized = 1;
274                 /*
275                  * Handle UP system running SMP kernel, with no CPU
276                  * entry in MADT
277                  */
278                 if ((cpu_index == -1) && (num_online_cpus() == 1))
279                         cpu_index = 0;
280         }
281         pr->id = cpu_index;
282 
283         /*
284          *  Extra Processor objects may be enumerated on MP systems with
285          *  less than the max # of CPUs. They should be ignored _iff
286          *  they are physically not present.
287          */
288         if (pr->id == -1) {
289                 int ret = acpi_processor_hotadd_init(pr);
290                 if (ret)
291                         return ret;
292         }
293 
294         /*
295          * On some boxes several processors use the same processor bus id.
296          * But they are located in different scope. For example:
297          * \_SB.SCK0.CPU0
298          * \_SB.SCK1.CPU0
299          * Rename the processor device bus id. And the new bus id will be
300          * generated as the following format:
301          * CPU+CPU ID.
302          */
303         sprintf(acpi_device_bid(device), "CPU%X", pr->id);
304         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Processor [%d:%d]\n", pr->id,
305                           pr->acpi_id));
306 
307         if (!object.processor.pblk_address)
308                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No PBLK (NULL address)\n"));
309         else if (object.processor.pblk_length != 6)
310                 dev_err(&device->dev, "Invalid PBLK length [%d]\n",
311                             object.processor.pblk_length);
312         else {
313                 pr->throttling.address = object.processor.pblk_address;
314                 pr->throttling.duty_offset = acpi_gbl_FADT.duty_offset;
315                 pr->throttling.duty_width = acpi_gbl_FADT.duty_width;
316 
317                 pr->pblk = object.processor.pblk_address;
318 
319                 /*
320                  * We don't care about error returns - we just try to mark
321                  * these reserved so that nobody else is confused into thinking
322                  * that this region might be unused..
323                  *
324                  * (In particular, allocating the IO range for Cardbus)
325                  */
326                 request_region(pr->throttling.address, 6, "ACPI CPU throttle");
327         }
328 
329         /*
330          * If ACPI describes a slot number for this CPU, we can use it to
331          * ensure we get the right value in the "physical id" field
332          * of /proc/cpuinfo
333          */
334         status = acpi_evaluate_integer(pr->handle, "_SUN", NULL, &value);
335         if (ACPI_SUCCESS(status))
336                 arch_fix_phys_package_id(pr->id, value);
337 
338         return 0;
339 }
340 
341 /*
342  * Do not put anything in here which needs the core to be online.
343  * For example MSR access or setting up things which check for cpuinfo_x86
344  * (cpu_data(cpu)) values, like CPU feature flags, family, model, etc.
345  * Such things have to be put in and set up by the processor driver's .probe().
346  */
347 static DEFINE_PER_CPU(void *, processor_device_array);
348 
349 static int acpi_processor_add(struct acpi_device *device,
350                                         const struct acpi_device_id *id)
351 {
352         struct acpi_processor *pr;
353         struct device *dev;
354         int result = 0;
355 
356         pr = kzalloc(sizeof(struct acpi_processor), GFP_KERNEL);
357         if (!pr)
358                 return -ENOMEM;
359 
360         if (!zalloc_cpumask_var(&pr->throttling.shared_cpu_map, GFP_KERNEL)) {
361                 result = -ENOMEM;
362                 goto err_free_pr;
363         }
364 
365         pr->handle = device->handle;
366         strcpy(acpi_device_name(device), ACPI_PROCESSOR_DEVICE_NAME);
367         strcpy(acpi_device_class(device), ACPI_PROCESSOR_CLASS);
368         device->driver_data = pr;
369 
370         result = acpi_processor_get_info(device);
371         if (result) /* Processor is not physically present or unavailable */
372                 return 0;
373 
374 #ifdef CONFIG_SMP
375         if (pr->id >= setup_max_cpus && pr->id != 0)
376                 return 0;
377 #endif
378 
379         BUG_ON(pr->id >= nr_cpu_ids);
380 
381         /*
382          * Buggy BIOS check.
383          * ACPI id of processors can be reported wrongly by the BIOS.
384          * Don't trust it blindly
385          */
386         if (per_cpu(processor_device_array, pr->id) != NULL &&
387             per_cpu(processor_device_array, pr->id) != device) {
388                 dev_warn(&device->dev,
389                         "BIOS reported wrong ACPI id %d for the processor\n",
390                         pr->id);
391                 /* Give up, but do not abort the namespace scan. */
392                 goto err;
393         }
394         /*
395          * processor_device_array is not cleared on errors to allow buggy BIOS
396          * checks.
397          */
398         per_cpu(processor_device_array, pr->id) = device;
399         per_cpu(processors, pr->id) = pr;
400 
401         dev = get_cpu_device(pr->id);
402         if (!dev) {
403                 result = -ENODEV;
404                 goto err;
405         }
406 
407         result = acpi_bind_one(dev, device);
408         if (result)
409                 goto err;
410 
411         pr->dev = dev;
412 
413         /* Trigger the processor driver's .probe() if present. */
414         if (device_attach(dev) >= 0)
415                 return 1;
416 
417         dev_err(dev, "Processor driver could not be attached\n");
418         acpi_unbind_one(dev);
419 
420  err:
421         free_cpumask_var(pr->throttling.shared_cpu_map);
422         device->driver_data = NULL;
423         per_cpu(processors, pr->id) = NULL;
424  err_free_pr:
425         kfree(pr);
426         return result;
427 }
428 
429 #ifdef CONFIG_ACPI_HOTPLUG_CPU
430 /* --------------------------------------------------------------------------
431                                     Removal
432    -------------------------------------------------------------------------- */
433 
434 static void acpi_processor_remove(struct acpi_device *device)
435 {
436         struct acpi_processor *pr;
437 
438         if (!device || !acpi_driver_data(device))
439                 return;
440 
441         pr = acpi_driver_data(device);
442         if (pr->id >= nr_cpu_ids)
443                 goto out;
444 
445         /*
446          * The only reason why we ever get here is CPU hot-removal.  The CPU is
447          * already offline and the ACPI device removal locking prevents it from
448          * being put back online at this point.
449          *
450          * Unbind the driver from the processor device and detach it from the
451          * ACPI companion object.
452          */
453         device_release_driver(pr->dev);
454         acpi_unbind_one(pr->dev);
455 
456         /* Clean up. */
457         per_cpu(processor_device_array, pr->id) = NULL;
458         per_cpu(processors, pr->id) = NULL;
459 
460         cpu_maps_update_begin();
461         cpu_hotplug_begin();
462 
463         /* Remove the CPU. */
464         arch_unregister_cpu(pr->id);
465         acpi_unmap_cpu(pr->id);
466 
467         cpu_hotplug_done();
468         cpu_maps_update_done();
469 
470         try_offline_node(cpu_to_node(pr->id));
471 
472  out:
473         free_cpumask_var(pr->throttling.shared_cpu_map);
474         kfree(pr);
475 }
476 #endif /* CONFIG_ACPI_HOTPLUG_CPU */
477 
478 /*
479  * The following ACPI IDs are known to be suitable for representing as
480  * processor devices.
481  */
482 static const struct acpi_device_id processor_device_ids[] = {
483 
484         { ACPI_PROCESSOR_OBJECT_HID, },
485         { ACPI_PROCESSOR_DEVICE_HID, },
486 
487         { }
488 };
489 
490 static struct acpi_scan_handler __refdata processor_handler = {
491         .ids = processor_device_ids,
492         .attach = acpi_processor_add,
493 #ifdef CONFIG_ACPI_HOTPLUG_CPU
494         .detach = acpi_processor_remove,
495 #endif
496         .hotplug = {
497                 .enabled = true,
498         },
499 };
500 
501 void __init acpi_processor_init(void)
502 {
503         acpi_scan_add_handler_with_hotplug(&processor_handler, "processor");
504 }
505 

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