pci_root.c revision ab8e8957a2ae21c0f036476c6db13e949be730ac 
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/proc_fs.h>
31#include <linux/spinlock.h>
32#include <linux/pm.h>
33#include <linux/pm_runtime.h>
34#include <linux/pci.h>
35#include <linux/pci-acpi.h>
36#include <linux/pci-aspm.h>
37#include <linux/acpi.h>
38#include <linux/slab.h>
39#include <acpi/acpi_bus.h>
40#include <acpi/acpi_drivers.h>
41
42#define PREFIX "ACPI: "
43
44#define _COMPONENT		ACPI_PCI_COMPONENT
45ACPI_MODULE_NAME("pci_root");
46#define ACPI_PCI_ROOT_CLASS		"pci_bridge"
47#define ACPI_PCI_ROOT_DEVICE_NAME	"PCI Root Bridge"
48static int acpi_pci_root_add(struct acpi_device *device);
49static int acpi_pci_root_remove(struct acpi_device *device, int type);
50static int acpi_pci_root_start(struct acpi_device *device);
51
52static const struct acpi_device_id root_device_ids[] = {
53	{"PNP0A03", 0},
54	{"", 0},
55};
56MODULE_DEVICE_TABLE(acpi, root_device_ids);
57
58static struct acpi_driver acpi_pci_root_driver = {
59	.name = "pci_root",
60	.class = ACPI_PCI_ROOT_CLASS,
61	.ids = root_device_ids,
62	.ops = {
63		.add = acpi_pci_root_add,
64		.remove = acpi_pci_root_remove,
65		.start = acpi_pci_root_start,
66		},
67};
68
69static LIST_HEAD(acpi_pci_roots);
70
71static struct acpi_pci_driver *sub_driver;
72static DEFINE_MUTEX(osc_lock);
73
74int acpi_pci_register_driver(struct acpi_pci_driver *driver)
75{
76	int n = 0;
77	struct acpi_pci_root *root;
78
79	struct acpi_pci_driver **pptr = &sub_driver;
80	while (*pptr)
81		pptr = &(*pptr)->next;
82	*pptr = driver;
83
84	if (!driver->add)
85		return 0;
86
87	list_for_each_entry(root, &acpi_pci_roots, node) {
88		driver->add(root->device->handle);
89		n++;
90	}
91
92	return n;
93}
94
95EXPORT_SYMBOL(acpi_pci_register_driver);
96
97void acpi_pci_unregister_driver(struct acpi_pci_driver *driver)
98{
99	struct acpi_pci_root *root;
100
101	struct acpi_pci_driver **pptr = &sub_driver;
102	while (*pptr) {
103		if (*pptr == driver)
104			break;
105		pptr = &(*pptr)->next;
106	}
107	BUG_ON(!*pptr);
108	*pptr = (*pptr)->next;
109
110	if (!driver->remove)
111		return;
112
113	list_for_each_entry(root, &acpi_pci_roots, node)
114		driver->remove(root->device->handle);
115}
116
117EXPORT_SYMBOL(acpi_pci_unregister_driver);
118
119acpi_handle acpi_get_pci_rootbridge_handle(unsigned int seg, unsigned int bus)
120{
121	struct acpi_pci_root *root;
122
123	list_for_each_entry(root, &acpi_pci_roots, node)
124		if ((root->segment == (u16) seg) &&
125		    (root->secondary.start == (u16) bus))
126			return root->device->handle;
127	return NULL;
128}
129
130EXPORT_SYMBOL_GPL(acpi_get_pci_rootbridge_handle);
131
132/**
133 * acpi_is_root_bridge - determine whether an ACPI CA node is a PCI root bridge
134 * @handle - the ACPI CA node in question.
135 *
136 * Note: we could make this API take a struct acpi_device * instead, but
137 * for now, it's more convenient to operate on an acpi_handle.
138 */
139int acpi_is_root_bridge(acpi_handle handle)
140{
141	int ret;
142	struct acpi_device *device;
143
144	ret = acpi_bus_get_device(handle, &device);
145	if (ret)
146		return 0;
147
148	ret = acpi_match_device_ids(device, root_device_ids);
149	if (ret)
150		return 0;
151	else
152		return 1;
153}
154EXPORT_SYMBOL_GPL(acpi_is_root_bridge);
155
156static acpi_status
157get_root_bridge_busnr_callback(struct acpi_resource *resource, void *data)
158{
159	struct resource *res = data;
160	struct acpi_resource_address64 address;
161
162	if (resource->type != ACPI_RESOURCE_TYPE_ADDRESS16 &&
163	    resource->type != ACPI_RESOURCE_TYPE_ADDRESS32 &&
164	    resource->type != ACPI_RESOURCE_TYPE_ADDRESS64)
165		return AE_OK;
166
167	acpi_resource_to_address64(resource, &address);
168	if ((address.address_length > 0) &&
169	    (address.resource_type == ACPI_BUS_NUMBER_RANGE)) {
170		res->start = address.minimum;
171		res->end = address.minimum + address.address_length - 1;
172	}
173
174	return AE_OK;
175}
176
177static acpi_status try_get_root_bridge_busnr(acpi_handle handle,
178					     struct resource *res)
179{
180	acpi_status status;
181
182	res->start = -1;
183	status =
184	    acpi_walk_resources(handle, METHOD_NAME__CRS,
185				get_root_bridge_busnr_callback, res);
186	if (ACPI_FAILURE(status))
187		return status;
188	if (res->start == -1)
189		return AE_ERROR;
190	return AE_OK;
191}
192
193static void acpi_pci_bridge_scan(struct acpi_device *device)
194{
195	int status;
196	struct acpi_device *child = NULL;
197
198	if (device->flags.bus_address)
199		if (device->parent && device->parent->ops.bind) {
200			status = device->parent->ops.bind(device);
201			if (!status) {
202				list_for_each_entry(child, &device->children, node)
203					acpi_pci_bridge_scan(child);
204			}
205		}
206}
207
208static u8 pci_osc_uuid_str[] = "33DB4D5B-1FF7-401C-9657-7441C03DD766";
209
210static acpi_status acpi_pci_run_osc(acpi_handle handle,
211				    const u32 *capbuf, u32 *retval)
212{
213	struct acpi_osc_context context = {
214		.uuid_str = pci_osc_uuid_str,
215		.rev = 1,
216		.cap.length = 12,
217		.cap.pointer = (void *)capbuf,
218	};
219	acpi_status status;
220
221	status = acpi_run_osc(handle, &context);
222	if (ACPI_SUCCESS(status)) {
223		*retval = *((u32 *)(context.ret.pointer + 8));
224		kfree(context.ret.pointer);
225	}
226	return status;
227}
228
229static acpi_status acpi_pci_query_osc(struct acpi_pci_root *root,
230					u32 support,
231					u32 *control)
232{
233	acpi_status status;
234	u32 result, capbuf[3];
235
236	support &= OSC_PCI_SUPPORT_MASKS;
237	support |= root->osc_support_set;
238
239	capbuf[OSC_QUERY_TYPE] = OSC_QUERY_ENABLE;
240	capbuf[OSC_SUPPORT_TYPE] = support;
241	if (control) {
242		*control &= OSC_PCI_CONTROL_MASKS;
243		capbuf[OSC_CONTROL_TYPE] = *control | root->osc_control_set;
244	} else {
245		/* Run _OSC query for all possible controls. */
246		capbuf[OSC_CONTROL_TYPE] = OSC_PCI_CONTROL_MASKS;
247	}
248
249	status = acpi_pci_run_osc(root->device->handle, capbuf, &result);
250	if (ACPI_SUCCESS(status)) {
251		root->osc_support_set = support;
252		if (control) {
253			*control = result;
254		} else {
255			root->osc_control_qry = result;
256			root->osc_queried = 1;
257		}
258	}
259	return status;
260}
261
262static acpi_status acpi_pci_osc_support(struct acpi_pci_root *root, u32 flags)
263{
264	acpi_status status;
265	acpi_handle tmp;
266
267	status = acpi_get_handle(root->device->handle, "_OSC", &tmp);
268	if (ACPI_FAILURE(status))
269		return status;
270	mutex_lock(&osc_lock);
271	status = acpi_pci_query_osc(root, flags, NULL);
272	mutex_unlock(&osc_lock);
273	return status;
274}
275
276struct acpi_pci_root *acpi_pci_find_root(acpi_handle handle)
277{
278	struct acpi_pci_root *root;
279
280	list_for_each_entry(root, &acpi_pci_roots, node) {
281		if (root->device->handle == handle)
282			return root;
283	}
284	return NULL;
285}
286EXPORT_SYMBOL_GPL(acpi_pci_find_root);
287
288struct acpi_handle_node {
289	struct list_head node;
290	acpi_handle handle;
291};
292
293/**
294 * acpi_get_pci_dev - convert ACPI CA handle to struct pci_dev
295 * @handle: the handle in question
296 *
297 * Given an ACPI CA handle, the desired PCI device is located in the
298 * list of PCI devices.
299 *
300 * If the device is found, its reference count is increased and this
301 * function returns a pointer to its data structure.  The caller must
302 * decrement the reference count by calling pci_dev_put().
303 * If no device is found, %NULL is returned.
304 */
305struct pci_dev *acpi_get_pci_dev(acpi_handle handle)
306{
307	int dev, fn;
308	unsigned long long adr;
309	acpi_status status;
310	acpi_handle phandle;
311	struct pci_bus *pbus;
312	struct pci_dev *pdev = NULL;
313	struct acpi_handle_node *node, *tmp;
314	struct acpi_pci_root *root;
315	LIST_HEAD(device_list);
316
317	/*
318	 * Walk up the ACPI CA namespace until we reach a PCI root bridge.
319	 */
320	phandle = handle;
321	while (!acpi_is_root_bridge(phandle)) {
322		node = kzalloc(sizeof(struct acpi_handle_node), GFP_KERNEL);
323		if (!node)
324			goto out;
325
326		INIT_LIST_HEAD(&node->node);
327		node->handle = phandle;
328		list_add(&node->node, &device_list);
329
330		status = acpi_get_parent(phandle, &phandle);
331		if (ACPI_FAILURE(status))
332			goto out;
333	}
334
335	root = acpi_pci_find_root(phandle);
336	if (!root)
337		goto out;
338
339	pbus = root->bus;
340
341	/*
342	 * Now, walk back down the PCI device tree until we return to our
343	 * original handle. Assumes that everything between the PCI root
344	 * bridge and the device we're looking for must be a P2P bridge.
345	 */
346	list_for_each_entry(node, &device_list, node) {
347		acpi_handle hnd = node->handle;
348		status = acpi_evaluate_integer(hnd, "_ADR", NULL, &adr);
349		if (ACPI_FAILURE(status))
350			goto out;
351		dev = (adr >> 16) & 0xffff;
352		fn  = adr & 0xffff;
353
354		pdev = pci_get_slot(pbus, PCI_DEVFN(dev, fn));
355		if (!pdev || hnd == handle)
356			break;
357
358		pbus = pdev->subordinate;
359		pci_dev_put(pdev);
360
361		/*
362		 * This function may be called for a non-PCI device that has a
363		 * PCI parent (eg. a disk under a PCI SATA controller).  In that
364		 * case pdev->subordinate will be NULL for the parent.
365		 */
366		if (!pbus) {
367			dev_dbg(&pdev->dev, "Not a PCI-to-PCI bridge\n");
368			pdev = NULL;
369			break;
370		}
371	}
372out:
373	list_for_each_entry_safe(node, tmp, &device_list, node)
374		kfree(node);
375
376	return pdev;
377}
378EXPORT_SYMBOL_GPL(acpi_get_pci_dev);
379
380/**
381 * acpi_pci_osc_control_set - commit requested control to Firmware
382 * @handle: acpi_handle for the target ACPI object
383 * @flags: driver's requested control bits
384 *
385 * Attempt to take control from Firmware on requested control bits.
386 **/
387acpi_status acpi_pci_osc_control_set(acpi_handle handle, u32 flags)
388{
389	acpi_status status;
390	u32 control_req, result, capbuf[3];
391	acpi_handle tmp;
392	struct acpi_pci_root *root;
393
394	control_req = (flags & OSC_PCI_CONTROL_MASKS);
395	if (!control_req)
396		return AE_TYPE;
397
398	root = acpi_pci_find_root(handle);
399	if (!root)
400		return AE_NOT_EXIST;
401
402	status = acpi_get_handle(handle, "_OSC", &tmp);
403	if (ACPI_FAILURE(status))
404		return status;
405
406	mutex_lock(&osc_lock);
407	/* No need to evaluate _OSC if the control was already granted. */
408	if ((root->osc_control_set & control_req) == control_req)
409		goto out;
410
411	/* Need to query controls first before requesting them */
412	if (!root->osc_queried) {
413		status = acpi_pci_query_osc(root, root->osc_support_set, NULL);
414		if (ACPI_FAILURE(status))
415			goto out;
416	}
417	if ((root->osc_control_qry & control_req) != control_req) {
418		printk(KERN_DEBUG
419		       "Firmware did not grant requested _OSC control\n");
420		status = AE_SUPPORT;
421		goto out;
422	}
423
424	capbuf[OSC_QUERY_TYPE] = 0;
425	capbuf[OSC_SUPPORT_TYPE] = root->osc_support_set;
426	capbuf[OSC_CONTROL_TYPE] = root->osc_control_set | control_req;
427	status = acpi_pci_run_osc(handle, capbuf, &result);
428	if (ACPI_SUCCESS(status))
429		root->osc_control_set = result;
430out:
431	mutex_unlock(&osc_lock);
432	return status;
433}
434EXPORT_SYMBOL(acpi_pci_osc_control_set);
435
436static int __devinit acpi_pci_root_add(struct acpi_device *device)
437{
438	unsigned long long segment, bus;
439	acpi_status status;
440	int result;
441	struct acpi_pci_root *root;
442	acpi_handle handle;
443	struct acpi_device *child;
444	u32 flags, base_flags;
445
446	root = kzalloc(sizeof(struct acpi_pci_root), GFP_KERNEL);
447	if (!root)
448		return -ENOMEM;
449
450	segment = 0;
451	status = acpi_evaluate_integer(device->handle, METHOD_NAME__SEG, NULL,
452				       &segment);
453	if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
454		printk(KERN_ERR PREFIX "can't evaluate _SEG\n");
455		result = -ENODEV;
456		goto end;
457	}
458
459	/* Check _CRS first, then _BBN.  If no _BBN, default to zero. */
460	root->secondary.flags = IORESOURCE_BUS;
461	status = try_get_root_bridge_busnr(device->handle, &root->secondary);
462	if (ACPI_FAILURE(status)) {
463		/*
464		 * We need both the start and end of the downstream bus range
465		 * to interpret _CBA (MMCONFIG base address), so it really is
466		 * supposed to be in _CRS.  If we don't find it there, all we
467		 * can do is assume [_BBN-0xFF] or [0-0xFF].
468		 */
469		root->secondary.end = 0xFF;
470		printk(KERN_WARNING FW_BUG PREFIX
471		       "no secondary bus range in _CRS\n");
472		status = acpi_evaluate_integer(device->handle, METHOD_NAME__BBN,					       NULL, &bus);
473		if (ACPI_SUCCESS(status))
474			root->secondary.start = bus;
475		else if (status == AE_NOT_FOUND)
476			root->secondary.start = 0;
477		else {
478			printk(KERN_ERR PREFIX "can't evaluate _BBN\n");
479			result = -ENODEV;
480			goto end;
481		}
482	}
483
484	INIT_LIST_HEAD(&root->node);
485	root->device = device;
486	root->segment = segment & 0xFFFF;
487	strcpy(acpi_device_name(device), ACPI_PCI_ROOT_DEVICE_NAME);
488	strcpy(acpi_device_class(device), ACPI_PCI_ROOT_CLASS);
489	device->driver_data = root;
490
491	/*
492	 * All supported architectures that use ACPI have support for
493	 * PCI domains, so we indicate this in _OSC support capabilities.
494	 */
495	flags = base_flags = OSC_PCI_SEGMENT_GROUPS_SUPPORT;
496	acpi_pci_osc_support(root, flags);
497
498	/*
499	 * TBD: Need PCI interface for enumeration/configuration of roots.
500	 */
501
502	/* TBD: Locking */
503	list_add_tail(&root->node, &acpi_pci_roots);
504
505	printk(KERN_INFO PREFIX "%s [%s] (domain %04x %pR)\n",
506	       acpi_device_name(device), acpi_device_bid(device),
507	       root->segment, &root->secondary);
508
509	/*
510	 * Scan the Root Bridge
511	 * --------------------
512	 * Must do this prior to any attempt to bind the root device, as the
513	 * PCI namespace does not get created until this call is made (and
514	 * thus the root bridge's pci_dev does not exist).
515	 */
516	root->bus = pci_acpi_scan_root(root);
517	if (!root->bus) {
518		printk(KERN_ERR PREFIX
519			    "Bus %04x:%02x not present in PCI namespace\n",
520			    root->segment, (unsigned int)root->secondary.start);
521		result = -ENODEV;
522		goto end;
523	}
524
525	/*
526	 * Attach ACPI-PCI Context
527	 * -----------------------
528	 * Thus binding the ACPI and PCI devices.
529	 */
530	result = acpi_pci_bind_root(device);
531	if (result)
532		goto end;
533
534	/*
535	 * PCI Routing Table
536	 * -----------------
537	 * Evaluate and parse _PRT, if exists.
538	 */
539	status = acpi_get_handle(device->handle, METHOD_NAME__PRT, &handle);
540	if (ACPI_SUCCESS(status))
541		result = acpi_pci_irq_add_prt(device->handle, root->bus);
542
543	/*
544	 * Scan and bind all _ADR-Based Devices
545	 */
546	list_for_each_entry(child, &device->children, node)
547		acpi_pci_bridge_scan(child);
548
549	/* Indicate support for various _OSC capabilities. */
550	if (pci_ext_cfg_avail(root->bus->self))
551		flags |= OSC_EXT_PCI_CONFIG_SUPPORT;
552	if (pcie_aspm_enabled())
553		flags |= OSC_ACTIVE_STATE_PWR_SUPPORT |
554			OSC_CLOCK_PWR_CAPABILITY_SUPPORT;
555	if (pci_msi_enabled())
556		flags |= OSC_MSI_SUPPORT;
557	if (flags != base_flags)
558		acpi_pci_osc_support(root, flags);
559
560	status = acpi_pci_osc_control_set(root->device->handle,
561					  OSC_PCI_EXPRESS_CAP_STRUCTURE_CONTROL);
562
563	if (ACPI_FAILURE(status)) {
564		printk(KERN_INFO "Unable to assume PCIe control: Disabling ASPM\n");
565		pcie_no_aspm();
566	}
567
568	pci_acpi_add_bus_pm_notifier(device, root->bus);
569	if (device->wakeup.flags.run_wake)
570		device_set_run_wake(root->bus->bridge, true);
571
572	return 0;
573
574end:
575	if (!list_empty(&root->node))
576		list_del(&root->node);
577	kfree(root);
578	return result;
579}
580
581static int acpi_pci_root_start(struct acpi_device *device)
582{
583	struct acpi_pci_root *root = acpi_driver_data(device);
584
585	pci_bus_add_devices(root->bus);
586	return 0;
587}
588
589static int acpi_pci_root_remove(struct acpi_device *device, int type)
590{
591	struct acpi_pci_root *root = acpi_driver_data(device);
592
593	device_set_run_wake(root->bus->bridge, false);
594	pci_acpi_remove_bus_pm_notifier(device);
595
596	kfree(root);
597	return 0;
598}
599
600static int __init acpi_pci_root_init(void)
601{
602	if (acpi_pci_disabled)
603		return 0;
604
605	pci_acpi_crs_quirks();
606	if (acpi_bus_register_driver(&acpi_pci_root_driver) < 0)
607		return -ENODEV;
608
609	return 0;
610}
611
612subsys_initcall(acpi_pci_root_init);
613