xref: /openbmc/linux/drivers/acpi/acpi_processor.c (revision c819e2cf)
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 == -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_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 	int phys_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 	phys_id = acpi_get_phys_id(pr->handle, device_declaration, pr->acpi_id);
266 	if (phys_id < 0)
267 		acpi_handle_debug(pr->handle, "failed to get CPU physical ID.\n");
268 	pr->phys_id = phys_id;
269 
270 	cpu_index = acpi_map_cpuid(pr->phys_id, pr->acpi_id);
271 	if (!cpu0_initialized && !acpi_has_cpu_in_madt()) {
272 		cpu0_initialized = 1;
273 		/*
274 		 * Handle UP system running SMP kernel, with no CPU
275 		 * entry in MADT
276 		 */
277 		if ((cpu_index == -1) && (num_online_cpus() == 1))
278 			cpu_index = 0;
279 	}
280 	pr->id = cpu_index;
281 
282 	/*
283 	 *  Extra Processor objects may be enumerated on MP systems with
284 	 *  less than the max # of CPUs. They should be ignored _iff
285 	 *  they are physically not present.
286 	 */
287 	if (pr->id == -1) {
288 		int ret = acpi_processor_hotadd_init(pr);
289 		if (ret)
290 			return ret;
291 	}
292 
293 	/*
294 	 * On some boxes several processors use the same processor bus id.
295 	 * But they are located in different scope. For example:
296 	 * \_SB.SCK0.CPU0
297 	 * \_SB.SCK1.CPU0
298 	 * Rename the processor device bus id. And the new bus id will be
299 	 * generated as the following format:
300 	 * CPU+CPU ID.
301 	 */
302 	sprintf(acpi_device_bid(device), "CPU%X", pr->id);
303 	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Processor [%d:%d]\n", pr->id,
304 			  pr->acpi_id));
305 
306 	if (!object.processor.pblk_address)
307 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No PBLK (NULL address)\n"));
308 	else if (object.processor.pblk_length != 6)
309 		dev_err(&device->dev, "Invalid PBLK length [%d]\n",
310 			    object.processor.pblk_length);
311 	else {
312 		pr->throttling.address = object.processor.pblk_address;
313 		pr->throttling.duty_offset = acpi_gbl_FADT.duty_offset;
314 		pr->throttling.duty_width = acpi_gbl_FADT.duty_width;
315 
316 		pr->pblk = object.processor.pblk_address;
317 
318 		/*
319 		 * We don't care about error returns - we just try to mark
320 		 * these reserved so that nobody else is confused into thinking
321 		 * that this region might be unused..
322 		 *
323 		 * (In particular, allocating the IO range for Cardbus)
324 		 */
325 		request_region(pr->throttling.address, 6, "ACPI CPU throttle");
326 	}
327 
328 	/*
329 	 * If ACPI describes a slot number for this CPU, we can use it to
330 	 * ensure we get the right value in the "physical id" field
331 	 * of /proc/cpuinfo
332 	 */
333 	status = acpi_evaluate_integer(pr->handle, "_SUN", NULL, &value);
334 	if (ACPI_SUCCESS(status))
335 		arch_fix_phys_package_id(pr->id, value);
336 
337 	return 0;
338 }
339 
340 /*
341  * Do not put anything in here which needs the core to be online.
342  * For example MSR access or setting up things which check for cpuinfo_x86
343  * (cpu_data(cpu)) values, like CPU feature flags, family, model, etc.
344  * Such things have to be put in and set up by the processor driver's .probe().
345  */
346 static DEFINE_PER_CPU(void *, processor_device_array);
347 
348 static int acpi_processor_add(struct acpi_device *device,
349 					const struct acpi_device_id *id)
350 {
351 	struct acpi_processor *pr;
352 	struct device *dev;
353 	int result = 0;
354 
355 	pr = kzalloc(sizeof(struct acpi_processor), GFP_KERNEL);
356 	if (!pr)
357 		return -ENOMEM;
358 
359 	if (!zalloc_cpumask_var(&pr->throttling.shared_cpu_map, GFP_KERNEL)) {
360 		result = -ENOMEM;
361 		goto err_free_pr;
362 	}
363 
364 	pr->handle = device->handle;
365 	strcpy(acpi_device_name(device), ACPI_PROCESSOR_DEVICE_NAME);
366 	strcpy(acpi_device_class(device), ACPI_PROCESSOR_CLASS);
367 	device->driver_data = pr;
368 
369 	result = acpi_processor_get_info(device);
370 	if (result) /* Processor is not physically present or unavailable */
371 		return 0;
372 
373 #ifdef CONFIG_SMP
374 	if (pr->id >= setup_max_cpus && pr->id != 0)
375 		return 0;
376 #endif
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 /* --------------------------------------------------------------------------
430                                     Removal
431    -------------------------------------------------------------------------- */
432 
433 static void acpi_processor_remove(struct acpi_device *device)
434 {
435 	struct acpi_processor *pr;
436 
437 	if (!device || !acpi_driver_data(device))
438 		return;
439 
440 	pr = acpi_driver_data(device);
441 	if (pr->id >= nr_cpu_ids)
442 		goto out;
443 
444 	/*
445 	 * The only reason why we ever get here is CPU hot-removal.  The CPU is
446 	 * already offline and the ACPI device removal locking prevents it from
447 	 * being put back online at this point.
448 	 *
449 	 * Unbind the driver from the processor device and detach it from the
450 	 * ACPI companion object.
451 	 */
452 	device_release_driver(pr->dev);
453 	acpi_unbind_one(pr->dev);
454 
455 	/* Clean up. */
456 	per_cpu(processor_device_array, pr->id) = NULL;
457 	per_cpu(processors, pr->id) = NULL;
458 
459 	cpu_maps_update_begin();
460 	cpu_hotplug_begin();
461 
462 	/* Remove the CPU. */
463 	arch_unregister_cpu(pr->id);
464 	acpi_unmap_cpu(pr->id);
465 
466 	cpu_hotplug_done();
467 	cpu_maps_update_done();
468 
469 	try_offline_node(cpu_to_node(pr->id));
470 
471  out:
472 	free_cpumask_var(pr->throttling.shared_cpu_map);
473 	kfree(pr);
474 }
475 #endif /* CONFIG_ACPI_HOTPLUG_CPU */
476 
477 /*
478  * The following ACPI IDs are known to be suitable for representing as
479  * processor devices.
480  */
481 static const struct acpi_device_id processor_device_ids[] = {
482 
483 	{ ACPI_PROCESSOR_OBJECT_HID, },
484 	{ ACPI_PROCESSOR_DEVICE_HID, },
485 
486 	{ }
487 };
488 
489 static struct acpi_scan_handler __refdata processor_handler = {
490 	.ids = processor_device_ids,
491 	.attach = acpi_processor_add,
492 #ifdef CONFIG_ACPI_HOTPLUG_CPU
493 	.detach = acpi_processor_remove,
494 #endif
495 	.hotplug = {
496 		.enabled = true,
497 	},
498 };
499 
500 void __init acpi_processor_init(void)
501 {
502 	acpi_scan_add_handler_with_hotplug(&processor_handler, "processor");
503 }
504