xref: /linux/drivers/acpi/pci_root.c (revision 765532c8aaac624b5f8687af6d319c6a1138a257)
1 /*
2  *  pci_root.c - ACPI PCI Root Bridge Driver ($Revision: 40 $)
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  *
7  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
8  *
9  *  This program is free software; you can redistribute it and/or modify
10  *  it under the terms of the GNU General Public License as published by
11  *  the Free Software Foundation; either version 2 of the License, or (at
12  *  your option) any later version.
13  *
14  *  This program is distributed in the hope that it will be useful, but
15  *  WITHOUT ANY WARRANTY; without even the implied warranty of
16  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
17  *  General Public License for more details.
18  *
19  *  You should have received a copy of the GNU General Public License along
20  *  with this program; if not, write to the Free Software Foundation, Inc.,
21  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
22  *
23  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
24  */
25 
26 #include <linux/kernel.h>
27 #include <linux/module.h>
28 #include <linux/init.h>
29 #include <linux/types.h>
30 #include <linux/spinlock.h>
31 #include <linux/pm.h>
32 #include <linux/pm_runtime.h>
33 #include <linux/pci.h>
34 #include <linux/pci-acpi.h>
35 #include <linux/acpi.h>
36 #include <linux/slab.h>
37 #include <acpi/acpi_bus.h>
38 #include <acpi/acpi_drivers.h>
39 
40 #define PREFIX "ACPI: "
41 
42 #define _COMPONENT		ACPI_PCI_COMPONENT
43 ACPI_MODULE_NAME("pci_root");
44 #define ACPI_PCI_ROOT_CLASS		"pci_bridge"
45 #define ACPI_PCI_ROOT_DEVICE_NAME	"PCI Root Bridge"
46 static int acpi_pci_root_add(struct acpi_device *device);
47 static int acpi_pci_root_remove(struct acpi_device *device, int type);
48 static int acpi_pci_root_start(struct acpi_device *device);
49 
50 static const struct acpi_device_id root_device_ids[] = {
51 	{"PNP0A03", 0},
52 	{"", 0},
53 };
54 MODULE_DEVICE_TABLE(acpi, root_device_ids);
55 
56 static struct acpi_driver acpi_pci_root_driver = {
57 	.name = "pci_root",
58 	.class = ACPI_PCI_ROOT_CLASS,
59 	.ids = root_device_ids,
60 	.ops = {
61 		.add = acpi_pci_root_add,
62 		.remove = acpi_pci_root_remove,
63 		.start = acpi_pci_root_start,
64 		},
65 };
66 
67 static LIST_HEAD(acpi_pci_roots);
68 
69 static struct acpi_pci_driver *sub_driver;
70 static DEFINE_MUTEX(osc_lock);
71 
72 int acpi_pci_register_driver(struct acpi_pci_driver *driver)
73 {
74 	int n = 0;
75 	struct acpi_pci_root *root;
76 
77 	struct acpi_pci_driver **pptr = &sub_driver;
78 	while (*pptr)
79 		pptr = &(*pptr)->next;
80 	*pptr = driver;
81 
82 	if (!driver->add)
83 		return 0;
84 
85 	list_for_each_entry(root, &acpi_pci_roots, node) {
86 		driver->add(root->device->handle);
87 		n++;
88 	}
89 
90 	return n;
91 }
92 
93 EXPORT_SYMBOL(acpi_pci_register_driver);
94 
95 void acpi_pci_unregister_driver(struct acpi_pci_driver *driver)
96 {
97 	struct acpi_pci_root *root;
98 
99 	struct acpi_pci_driver **pptr = &sub_driver;
100 	while (*pptr) {
101 		if (*pptr == driver)
102 			break;
103 		pptr = &(*pptr)->next;
104 	}
105 	BUG_ON(!*pptr);
106 	*pptr = (*pptr)->next;
107 
108 	if (!driver->remove)
109 		return;
110 
111 	list_for_each_entry(root, &acpi_pci_roots, node)
112 		driver->remove(root->device->handle);
113 }
114 
115 EXPORT_SYMBOL(acpi_pci_unregister_driver);
116 
117 acpi_handle acpi_get_pci_rootbridge_handle(unsigned int seg, unsigned int bus)
118 {
119 	struct acpi_pci_root *root;
120 
121 	list_for_each_entry(root, &acpi_pci_roots, node)
122 		if ((root->segment == (u16) seg) &&
123 		    (root->secondary.start == (u16) bus))
124 			return root->device->handle;
125 	return NULL;
126 }
127 
128 EXPORT_SYMBOL_GPL(acpi_get_pci_rootbridge_handle);
129 
130 /**
131  * acpi_is_root_bridge - determine whether an ACPI CA node is a PCI root bridge
132  * @handle - the ACPI CA node in question.
133  *
134  * Note: we could make this API take a struct acpi_device * instead, but
135  * for now, it's more convenient to operate on an acpi_handle.
136  */
137 int acpi_is_root_bridge(acpi_handle handle)
138 {
139 	int ret;
140 	struct acpi_device *device;
141 
142 	ret = acpi_bus_get_device(handle, &device);
143 	if (ret)
144 		return 0;
145 
146 	ret = acpi_match_device_ids(device, root_device_ids);
147 	if (ret)
148 		return 0;
149 	else
150 		return 1;
151 }
152 EXPORT_SYMBOL_GPL(acpi_is_root_bridge);
153 
154 static acpi_status
155 get_root_bridge_busnr_callback(struct acpi_resource *resource, void *data)
156 {
157 	struct resource *res = data;
158 	struct acpi_resource_address64 address;
159 
160 	if (resource->type != ACPI_RESOURCE_TYPE_ADDRESS16 &&
161 	    resource->type != ACPI_RESOURCE_TYPE_ADDRESS32 &&
162 	    resource->type != ACPI_RESOURCE_TYPE_ADDRESS64)
163 		return AE_OK;
164 
165 	acpi_resource_to_address64(resource, &address);
166 	if ((address.address_length > 0) &&
167 	    (address.resource_type == ACPI_BUS_NUMBER_RANGE)) {
168 		res->start = address.minimum;
169 		res->end = address.minimum + address.address_length - 1;
170 	}
171 
172 	return AE_OK;
173 }
174 
175 static acpi_status try_get_root_bridge_busnr(acpi_handle handle,
176 					     struct resource *res)
177 {
178 	acpi_status status;
179 
180 	res->start = -1;
181 	status =
182 	    acpi_walk_resources(handle, METHOD_NAME__CRS,
183 				get_root_bridge_busnr_callback, res);
184 	if (ACPI_FAILURE(status))
185 		return status;
186 	if (res->start == -1)
187 		return AE_ERROR;
188 	return AE_OK;
189 }
190 
191 static void acpi_pci_bridge_scan(struct acpi_device *device)
192 {
193 	int status;
194 	struct acpi_device *child = NULL;
195 
196 	if (device->flags.bus_address)
197 		if (device->parent && device->parent->ops.bind) {
198 			status = device->parent->ops.bind(device);
199 			if (!status) {
200 				list_for_each_entry(child, &device->children, node)
201 					acpi_pci_bridge_scan(child);
202 			}
203 		}
204 }
205 
206 static u8 pci_osc_uuid_str[] = "33DB4D5B-1FF7-401C-9657-7441C03DD766";
207 
208 static acpi_status acpi_pci_run_osc(acpi_handle handle,
209 				    const u32 *capbuf, u32 *retval)
210 {
211 	struct acpi_osc_context context = {
212 		.uuid_str = pci_osc_uuid_str,
213 		.rev = 1,
214 		.cap.length = 12,
215 		.cap.pointer = (void *)capbuf,
216 	};
217 	acpi_status status;
218 
219 	status = acpi_run_osc(handle, &context);
220 	if (ACPI_SUCCESS(status)) {
221 		*retval = *((u32 *)(context.ret.pointer + 8));
222 		kfree(context.ret.pointer);
223 	}
224 	return status;
225 }
226 
227 static acpi_status acpi_pci_query_osc(struct acpi_pci_root *root,
228 					u32 support,
229 					u32 *control)
230 {
231 	acpi_status status;
232 	u32 result, capbuf[3];
233 
234 	support &= OSC_PCI_SUPPORT_MASKS;
235 	support |= root->osc_support_set;
236 
237 	capbuf[OSC_QUERY_TYPE] = OSC_QUERY_ENABLE;
238 	capbuf[OSC_SUPPORT_TYPE] = support;
239 	if (control) {
240 		*control &= OSC_PCI_CONTROL_MASKS;
241 		capbuf[OSC_CONTROL_TYPE] = *control | root->osc_control_set;
242 	} else {
243 		/* Run _OSC query for all possible controls. */
244 		capbuf[OSC_CONTROL_TYPE] = OSC_PCI_CONTROL_MASKS;
245 	}
246 
247 	status = acpi_pci_run_osc(root->device->handle, capbuf, &result);
248 	if (ACPI_SUCCESS(status)) {
249 		root->osc_support_set = support;
250 		if (control)
251 			*control = result;
252 	}
253 	return status;
254 }
255 
256 static acpi_status acpi_pci_osc_support(struct acpi_pci_root *root, u32 flags)
257 {
258 	acpi_status status;
259 	acpi_handle tmp;
260 
261 	status = acpi_get_handle(root->device->handle, "_OSC", &tmp);
262 	if (ACPI_FAILURE(status))
263 		return status;
264 	mutex_lock(&osc_lock);
265 	status = acpi_pci_query_osc(root, flags, NULL);
266 	mutex_unlock(&osc_lock);
267 	return status;
268 }
269 
270 struct acpi_pci_root *acpi_pci_find_root(acpi_handle handle)
271 {
272 	struct acpi_pci_root *root;
273 
274 	list_for_each_entry(root, &acpi_pci_roots, node) {
275 		if (root->device->handle == handle)
276 			return root;
277 	}
278 	return NULL;
279 }
280 EXPORT_SYMBOL_GPL(acpi_pci_find_root);
281 
282 struct acpi_handle_node {
283 	struct list_head node;
284 	acpi_handle handle;
285 };
286 
287 /**
288  * acpi_get_pci_dev - convert ACPI CA handle to struct pci_dev
289  * @handle: the handle in question
290  *
291  * Given an ACPI CA handle, the desired PCI device is located in the
292  * list of PCI devices.
293  *
294  * If the device is found, its reference count is increased and this
295  * function returns a pointer to its data structure.  The caller must
296  * decrement the reference count by calling pci_dev_put().
297  * If no device is found, %NULL is returned.
298  */
299 struct pci_dev *acpi_get_pci_dev(acpi_handle handle)
300 {
301 	int dev, fn;
302 	unsigned long long adr;
303 	acpi_status status;
304 	acpi_handle phandle;
305 	struct pci_bus *pbus;
306 	struct pci_dev *pdev = NULL;
307 	struct acpi_handle_node *node, *tmp;
308 	struct acpi_pci_root *root;
309 	LIST_HEAD(device_list);
310 
311 	/*
312 	 * Walk up the ACPI CA namespace until we reach a PCI root bridge.
313 	 */
314 	phandle = handle;
315 	while (!acpi_is_root_bridge(phandle)) {
316 		node = kzalloc(sizeof(struct acpi_handle_node), GFP_KERNEL);
317 		if (!node)
318 			goto out;
319 
320 		INIT_LIST_HEAD(&node->node);
321 		node->handle = phandle;
322 		list_add(&node->node, &device_list);
323 
324 		status = acpi_get_parent(phandle, &phandle);
325 		if (ACPI_FAILURE(status))
326 			goto out;
327 	}
328 
329 	root = acpi_pci_find_root(phandle);
330 	if (!root)
331 		goto out;
332 
333 	pbus = root->bus;
334 
335 	/*
336 	 * Now, walk back down the PCI device tree until we return to our
337 	 * original handle. Assumes that everything between the PCI root
338 	 * bridge and the device we're looking for must be a P2P bridge.
339 	 */
340 	list_for_each_entry(node, &device_list, node) {
341 		acpi_handle hnd = node->handle;
342 		status = acpi_evaluate_integer(hnd, "_ADR", NULL, &adr);
343 		if (ACPI_FAILURE(status))
344 			goto out;
345 		dev = (adr >> 16) & 0xffff;
346 		fn  = adr & 0xffff;
347 
348 		pdev = pci_get_slot(pbus, PCI_DEVFN(dev, fn));
349 		if (!pdev || hnd == handle)
350 			break;
351 
352 		pbus = pdev->subordinate;
353 		pci_dev_put(pdev);
354 
355 		/*
356 		 * This function may be called for a non-PCI device that has a
357 		 * PCI parent (eg. a disk under a PCI SATA controller).  In that
358 		 * case pdev->subordinate will be NULL for the parent.
359 		 */
360 		if (!pbus) {
361 			dev_dbg(&pdev->dev, "Not a PCI-to-PCI bridge\n");
362 			pdev = NULL;
363 			break;
364 		}
365 	}
366 out:
367 	list_for_each_entry_safe(node, tmp, &device_list, node)
368 		kfree(node);
369 
370 	return pdev;
371 }
372 EXPORT_SYMBOL_GPL(acpi_get_pci_dev);
373 
374 /**
375  * acpi_pci_osc_control_set - Request control of PCI root _OSC features.
376  * @handle: ACPI handle of a PCI root bridge (or PCIe Root Complex).
377  * @mask: Mask of _OSC bits to request control of, place to store control mask.
378  * @req: Mask of _OSC bits the control of is essential to the caller.
379  *
380  * Run _OSC query for @mask and if that is successful, compare the returned
381  * mask of control bits with @req.  If all of the @req bits are set in the
382  * returned mask, run _OSC request for it.
383  *
384  * The variable at the @mask address may be modified regardless of whether or
385  * not the function returns success.  On success it will contain the mask of
386  * _OSC bits the BIOS has granted control of, but its contents are meaningless
387  * on failure.
388  **/
389 acpi_status acpi_pci_osc_control_set(acpi_handle handle, u32 *mask, u32 req)
390 {
391 	struct acpi_pci_root *root;
392 	acpi_status status;
393 	u32 ctrl, capbuf[3];
394 	acpi_handle tmp;
395 
396 	if (!mask)
397 		return AE_BAD_PARAMETER;
398 
399 	ctrl = *mask & OSC_PCI_CONTROL_MASKS;
400 	if ((ctrl & req) != req)
401 		return AE_TYPE;
402 
403 	root = acpi_pci_find_root(handle);
404 	if (!root)
405 		return AE_NOT_EXIST;
406 
407 	status = acpi_get_handle(handle, "_OSC", &tmp);
408 	if (ACPI_FAILURE(status))
409 		return status;
410 
411 	mutex_lock(&osc_lock);
412 
413 	*mask = ctrl | root->osc_control_set;
414 	/* No need to evaluate _OSC if the control was already granted. */
415 	if ((root->osc_control_set & ctrl) == ctrl)
416 		goto out;
417 
418 	/* Need to check the available controls bits before requesting them. */
419 	while (*mask) {
420 		status = acpi_pci_query_osc(root, root->osc_support_set, mask);
421 		if (ACPI_FAILURE(status))
422 			goto out;
423 		if (ctrl == *mask)
424 			break;
425 		ctrl = *mask;
426 	}
427 
428 	if ((ctrl & req) != req) {
429 		status = AE_SUPPORT;
430 		goto out;
431 	}
432 
433 	capbuf[OSC_QUERY_TYPE] = 0;
434 	capbuf[OSC_SUPPORT_TYPE] = root->osc_support_set;
435 	capbuf[OSC_CONTROL_TYPE] = ctrl;
436 	status = acpi_pci_run_osc(handle, capbuf, mask);
437 	if (ACPI_SUCCESS(status))
438 		root->osc_control_set = *mask;
439 out:
440 	mutex_unlock(&osc_lock);
441 	return status;
442 }
443 EXPORT_SYMBOL(acpi_pci_osc_control_set);
444 
445 static int __devinit acpi_pci_root_add(struct acpi_device *device)
446 {
447 	unsigned long long segment, bus;
448 	acpi_status status;
449 	int result;
450 	struct acpi_pci_root *root;
451 	acpi_handle handle;
452 	struct acpi_device *child;
453 	u32 flags, base_flags;
454 
455 	root = kzalloc(sizeof(struct acpi_pci_root), GFP_KERNEL);
456 	if (!root)
457 		return -ENOMEM;
458 
459 	segment = 0;
460 	status = acpi_evaluate_integer(device->handle, METHOD_NAME__SEG, NULL,
461 				       &segment);
462 	if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
463 		printk(KERN_ERR PREFIX "can't evaluate _SEG\n");
464 		result = -ENODEV;
465 		goto end;
466 	}
467 
468 	/* Check _CRS first, then _BBN.  If no _BBN, default to zero. */
469 	root->secondary.flags = IORESOURCE_BUS;
470 	status = try_get_root_bridge_busnr(device->handle, &root->secondary);
471 	if (ACPI_FAILURE(status)) {
472 		/*
473 		 * We need both the start and end of the downstream bus range
474 		 * to interpret _CBA (MMCONFIG base address), so it really is
475 		 * supposed to be in _CRS.  If we don't find it there, all we
476 		 * can do is assume [_BBN-0xFF] or [0-0xFF].
477 		 */
478 		root->secondary.end = 0xFF;
479 		printk(KERN_WARNING FW_BUG PREFIX
480 		       "no secondary bus range in _CRS\n");
481 		status = acpi_evaluate_integer(device->handle, METHOD_NAME__BBN,					       NULL, &bus);
482 		if (ACPI_SUCCESS(status))
483 			root->secondary.start = bus;
484 		else if (status == AE_NOT_FOUND)
485 			root->secondary.start = 0;
486 		else {
487 			printk(KERN_ERR PREFIX "can't evaluate _BBN\n");
488 			result = -ENODEV;
489 			goto end;
490 		}
491 	}
492 
493 	INIT_LIST_HEAD(&root->node);
494 	root->device = device;
495 	root->segment = segment & 0xFFFF;
496 	strcpy(acpi_device_name(device), ACPI_PCI_ROOT_DEVICE_NAME);
497 	strcpy(acpi_device_class(device), ACPI_PCI_ROOT_CLASS);
498 	device->driver_data = root;
499 
500 	/*
501 	 * All supported architectures that use ACPI have support for
502 	 * PCI domains, so we indicate this in _OSC support capabilities.
503 	 */
504 	flags = base_flags = OSC_PCI_SEGMENT_GROUPS_SUPPORT;
505 	acpi_pci_osc_support(root, flags);
506 
507 	/*
508 	 * TBD: Need PCI interface for enumeration/configuration of roots.
509 	 */
510 
511 	/* TBD: Locking */
512 	list_add_tail(&root->node, &acpi_pci_roots);
513 
514 	printk(KERN_INFO PREFIX "%s [%s] (domain %04x %pR)\n",
515 	       acpi_device_name(device), acpi_device_bid(device),
516 	       root->segment, &root->secondary);
517 
518 	/*
519 	 * Scan the Root Bridge
520 	 * --------------------
521 	 * Must do this prior to any attempt to bind the root device, as the
522 	 * PCI namespace does not get created until this call is made (and
523 	 * thus the root bridge's pci_dev does not exist).
524 	 */
525 	root->bus = pci_acpi_scan_root(root);
526 	if (!root->bus) {
527 		printk(KERN_ERR PREFIX
528 			    "Bus %04x:%02x not present in PCI namespace\n",
529 			    root->segment, (unsigned int)root->secondary.start);
530 		result = -ENODEV;
531 		goto end;
532 	}
533 
534 	/*
535 	 * Attach ACPI-PCI Context
536 	 * -----------------------
537 	 * Thus binding the ACPI and PCI devices.
538 	 */
539 	result = acpi_pci_bind_root(device);
540 	if (result)
541 		goto end;
542 
543 	/*
544 	 * PCI Routing Table
545 	 * -----------------
546 	 * Evaluate and parse _PRT, if exists.
547 	 */
548 	status = acpi_get_handle(device->handle, METHOD_NAME__PRT, &handle);
549 	if (ACPI_SUCCESS(status))
550 		result = acpi_pci_irq_add_prt(device->handle, root->bus);
551 
552 	/*
553 	 * Scan and bind all _ADR-Based Devices
554 	 */
555 	list_for_each_entry(child, &device->children, node)
556 		acpi_pci_bridge_scan(child);
557 
558 	/* Indicate support for various _OSC capabilities. */
559 	if (pci_ext_cfg_avail(root->bus->self))
560 		flags |= OSC_EXT_PCI_CONFIG_SUPPORT;
561 	if (pcie_aspm_enabled())
562 		flags |= OSC_ACTIVE_STATE_PWR_SUPPORT |
563 			OSC_CLOCK_PWR_CAPABILITY_SUPPORT;
564 	if (pci_msi_enabled())
565 		flags |= OSC_MSI_SUPPORT;
566 	if (flags != base_flags)
567 		acpi_pci_osc_support(root, flags);
568 
569 	pci_acpi_add_bus_pm_notifier(device, root->bus);
570 	if (device->wakeup.flags.run_wake)
571 		device_set_run_wake(root->bus->bridge, true);
572 
573 	return 0;
574 
575 end:
576 	if (!list_empty(&root->node))
577 		list_del(&root->node);
578 	kfree(root);
579 	return result;
580 }
581 
582 static int acpi_pci_root_start(struct acpi_device *device)
583 {
584 	struct acpi_pci_root *root = acpi_driver_data(device);
585 
586 	pci_bus_add_devices(root->bus);
587 	return 0;
588 }
589 
590 static int acpi_pci_root_remove(struct acpi_device *device, int type)
591 {
592 	struct acpi_pci_root *root = acpi_driver_data(device);
593 
594 	device_set_run_wake(root->bus->bridge, false);
595 	pci_acpi_remove_bus_pm_notifier(device);
596 
597 	kfree(root);
598 	return 0;
599 }
600 
601 static int __init acpi_pci_root_init(void)
602 {
603 	if (acpi_pci_disabled)
604 		return 0;
605 
606 	pci_acpi_crs_quirks();
607 	if (acpi_bus_register_driver(&acpi_pci_root_driver) < 0)
608 		return -ENODEV;
609 
610 	return 0;
611 }
612 
613 subsys_initcall(acpi_pci_root_init);
614