pci_root.c revision 412af97838828bc6d035a1902c8974f944663da6 
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/pci.h>
34#include <linux/pci-acpi.h>
35#include <linux/acpi.h>
36#include <acpi/acpi_bus.h>
37#include <acpi/acpi_drivers.h>
38
39#define _COMPONENT		ACPI_PCI_COMPONENT
40ACPI_MODULE_NAME("pci_root");
41#define ACPI_PCI_ROOT_CLASS		"pci_bridge"
42#define ACPI_PCI_ROOT_DEVICE_NAME	"PCI Root Bridge"
43static int acpi_pci_root_add(struct acpi_device *device);
44static int acpi_pci_root_remove(struct acpi_device *device, int type);
45static int acpi_pci_root_start(struct acpi_device *device);
46
47static struct acpi_device_id root_device_ids[] = {
48	{"PNP0A03", 0},
49	{"", 0},
50};
51MODULE_DEVICE_TABLE(acpi, root_device_ids);
52
53static struct acpi_driver acpi_pci_root_driver = {
54	.name = "pci_root",
55	.class = ACPI_PCI_ROOT_CLASS,
56	.ids = root_device_ids,
57	.ops = {
58		.add = acpi_pci_root_add,
59		.remove = acpi_pci_root_remove,
60		.start = acpi_pci_root_start,
61		},
62};
63
64struct acpi_pci_root {
65	struct list_head node;
66	struct acpi_device *device;
67	struct pci_bus *bus;
68	u16 segment;
69	u8 bus_nr;
70
71	u32 osc_support_set;	/* _OSC state of support bits */
72	u32 osc_control_set;	/* _OSC state of control bits */
73	u32 osc_control_qry;	/* the latest _OSC query result */
74
75	u32 osc_queried:1;	/* has _OSC control been queried? */
76};
77
78static LIST_HEAD(acpi_pci_roots);
79
80static struct acpi_pci_driver *sub_driver;
81static DEFINE_MUTEX(osc_lock);
82
83int acpi_pci_register_driver(struct acpi_pci_driver *driver)
84{
85	int n = 0;
86	struct acpi_pci_root *root;
87
88	struct acpi_pci_driver **pptr = &sub_driver;
89	while (*pptr)
90		pptr = &(*pptr)->next;
91	*pptr = driver;
92
93	if (!driver->add)
94		return 0;
95
96	list_for_each_entry(root, &acpi_pci_roots, node) {
97		driver->add(root->device->handle);
98		n++;
99	}
100
101	return n;
102}
103
104EXPORT_SYMBOL(acpi_pci_register_driver);
105
106void acpi_pci_unregister_driver(struct acpi_pci_driver *driver)
107{
108	struct acpi_pci_root *root;
109
110	struct acpi_pci_driver **pptr = &sub_driver;
111	while (*pptr) {
112		if (*pptr == driver)
113			break;
114		pptr = &(*pptr)->next;
115	}
116	BUG_ON(!*pptr);
117	*pptr = (*pptr)->next;
118
119	if (!driver->remove)
120		return;
121
122	list_for_each_entry(root, &acpi_pci_roots, node)
123		driver->remove(root->device->handle);
124}
125
126EXPORT_SYMBOL(acpi_pci_unregister_driver);
127
128acpi_handle acpi_get_pci_rootbridge_handle(unsigned int seg, unsigned int bus)
129{
130	struct acpi_pci_root *root;
131
132	list_for_each_entry(root, &acpi_pci_roots, node)
133		if ((root->segment == (u16) seg) && (root->bus_nr == (u16) bus))
134			return root->device->handle;
135	return NULL;
136}
137
138EXPORT_SYMBOL_GPL(acpi_get_pci_rootbridge_handle);
139
140/**
141 * acpi_is_root_bridge - determine whether an ACPI CA node is a PCI root bridge
142 * @handle - the ACPI CA node in question.
143 *
144 * Note: we could make this API take a struct acpi_device * instead, but
145 * for now, it's more convenient to operate on an acpi_handle.
146 */
147int acpi_is_root_bridge(acpi_handle handle)
148{
149	int ret;
150	struct acpi_device *device;
151
152	ret = acpi_bus_get_device(handle, &device);
153	if (ret)
154		return 0;
155
156	ret = acpi_match_device_ids(device, root_device_ids);
157	if (ret)
158		return 0;
159	else
160		return 1;
161}
162EXPORT_SYMBOL_GPL(acpi_is_root_bridge);
163
164static acpi_status
165get_root_bridge_busnr_callback(struct acpi_resource *resource, void *data)
166{
167	int *busnr = data;
168	struct acpi_resource_address64 address;
169
170	if (resource->type != ACPI_RESOURCE_TYPE_ADDRESS16 &&
171	    resource->type != ACPI_RESOURCE_TYPE_ADDRESS32 &&
172	    resource->type != ACPI_RESOURCE_TYPE_ADDRESS64)
173		return AE_OK;
174
175	acpi_resource_to_address64(resource, &address);
176	if ((address.address_length > 0) &&
177	    (address.resource_type == ACPI_BUS_NUMBER_RANGE))
178		*busnr = address.minimum;
179
180	return AE_OK;
181}
182
183static acpi_status try_get_root_bridge_busnr(acpi_handle handle,
184					     unsigned long long *bus)
185{
186	acpi_status status;
187	int busnum;
188
189	busnum = -1;
190	status =
191	    acpi_walk_resources(handle, METHOD_NAME__CRS,
192				get_root_bridge_busnr_callback, &busnum);
193	if (ACPI_FAILURE(status))
194		return status;
195	/* Check if we really get a bus number from _CRS */
196	if (busnum == -1)
197		return AE_ERROR;
198	*bus = busnum;
199	return AE_OK;
200}
201
202static void acpi_pci_bridge_scan(struct acpi_device *device)
203{
204	int status;
205	struct acpi_device *child = NULL;
206
207	if (device->flags.bus_address)
208		if (device->parent && device->parent->ops.bind) {
209			status = device->parent->ops.bind(device);
210			if (!status) {
211				list_for_each_entry(child, &device->children, node)
212					acpi_pci_bridge_scan(child);
213			}
214		}
215}
216
217static u8 OSC_UUID[16] = {0x5B, 0x4D, 0xDB, 0x33, 0xF7, 0x1F, 0x1C, 0x40,
218			  0x96, 0x57, 0x74, 0x41, 0xC0, 0x3D, 0xD7, 0x66};
219
220static acpi_status acpi_pci_run_osc(acpi_handle handle,
221				    const u32 *capbuf, u32 *retval)
222{
223	acpi_status status;
224	struct acpi_object_list input;
225	union acpi_object in_params[4];
226	struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL};
227	union acpi_object *out_obj;
228	u32 errors;
229
230	/* Setting up input parameters */
231	input.count = 4;
232	input.pointer = in_params;
233	in_params[0].type 		= ACPI_TYPE_BUFFER;
234	in_params[0].buffer.length 	= 16;
235	in_params[0].buffer.pointer	= OSC_UUID;
236	in_params[1].type 		= ACPI_TYPE_INTEGER;
237	in_params[1].integer.value 	= 1;
238	in_params[2].type 		= ACPI_TYPE_INTEGER;
239	in_params[2].integer.value	= 3;
240	in_params[3].type		= ACPI_TYPE_BUFFER;
241	in_params[3].buffer.length 	= 12;
242	in_params[3].buffer.pointer 	= (u8 *)capbuf;
243
244	status = acpi_evaluate_object(handle, "_OSC", &input, &output);
245	if (ACPI_FAILURE(status))
246		return status;
247
248	if (!output.length)
249		return AE_NULL_OBJECT;
250
251	out_obj = output.pointer;
252	if (out_obj->type != ACPI_TYPE_BUFFER) {
253		printk(KERN_DEBUG "_OSC evaluation returned wrong type\n");
254		status = AE_TYPE;
255		goto out_kfree;
256	}
257	/* Need to ignore the bit0 in result code */
258	errors = *((u32 *)out_obj->buffer.pointer) & ~(1 << 0);
259	if (errors) {
260		if (errors & OSC_REQUEST_ERROR)
261			printk(KERN_DEBUG "_OSC request failed\n");
262		if (errors & OSC_INVALID_UUID_ERROR)
263			printk(KERN_DEBUG "_OSC invalid UUID\n");
264		if (errors & OSC_INVALID_REVISION_ERROR)
265			printk(KERN_DEBUG "_OSC invalid revision\n");
266		if (errors & OSC_CAPABILITIES_MASK_ERROR) {
267			if (capbuf[OSC_QUERY_TYPE] & OSC_QUERY_ENABLE)
268				goto out_success;
269			printk(KERN_DEBUG
270			       "Firmware did not grant requested _OSC control\n");
271			status = AE_SUPPORT;
272			goto out_kfree;
273		}
274		status = AE_ERROR;
275		goto out_kfree;
276	}
277out_success:
278	*retval = *((u32 *)(out_obj->buffer.pointer + 8));
279	status = AE_OK;
280
281out_kfree:
282	kfree(output.pointer);
283	return status;
284}
285
286static acpi_status acpi_pci_query_osc(struct acpi_pci_root *root, u32 flags)
287{
288	acpi_status status;
289	u32 support_set, result, capbuf[3];
290
291	/* do _OSC query for all possible controls */
292	support_set = root->osc_support_set | (flags & OSC_SUPPORT_MASKS);
293	capbuf[OSC_QUERY_TYPE] = OSC_QUERY_ENABLE;
294	capbuf[OSC_SUPPORT_TYPE] = support_set;
295	capbuf[OSC_CONTROL_TYPE] = OSC_CONTROL_MASKS;
296
297	status = acpi_pci_run_osc(root->device->handle, capbuf, &result);
298	if (ACPI_SUCCESS(status)) {
299		root->osc_support_set = support_set;
300		root->osc_control_qry = result;
301		root->osc_queried = 1;
302	}
303	return status;
304}
305
306static acpi_status acpi_pci_osc_support(struct acpi_pci_root *root, u32 flags)
307{
308	acpi_status status;
309	acpi_handle tmp;
310
311	status = acpi_get_handle(root->device->handle, "_OSC", &tmp);
312	if (ACPI_FAILURE(status))
313		return status;
314	mutex_lock(&osc_lock);
315	status = acpi_pci_query_osc(root, flags);
316	mutex_unlock(&osc_lock);
317	return status;
318}
319
320static struct acpi_pci_root *acpi_pci_find_root(acpi_handle handle)
321{
322	struct acpi_pci_root *root;
323
324	list_for_each_entry(root, &acpi_pci_roots, node) {
325		if (root->device->handle == handle)
326			return root;
327	}
328	return NULL;
329}
330
331struct acpi_handle_node {
332	struct list_head node;
333	acpi_handle handle;
334};
335
336/**
337 * acpi_get_pci_dev - convert ACPI CA handle to struct pci_dev
338 * @handle: the handle in question
339 *
340 * Given an ACPI CA handle, the desired PCI device is located in the
341 * list of PCI devices.
342 *
343 * If the device is found, its reference count is increased and this
344 * function returns a pointer to its data structure.  The caller must
345 * decrement the reference count by calling pci_dev_put().
346 * If no device is found, %NULL is returned.
347 */
348struct pci_dev *acpi_get_pci_dev(acpi_handle handle)
349{
350	int dev, fn;
351	unsigned long long adr;
352	acpi_status status;
353	acpi_handle phandle;
354	struct pci_bus *pbus;
355	struct pci_dev *pdev = NULL;
356	struct acpi_handle_node *node, *tmp;
357	struct acpi_pci_root *root;
358	LIST_HEAD(device_list);
359
360	/*
361	 * Walk up the ACPI CA namespace until we reach a PCI root bridge.
362	 */
363	phandle = handle;
364	while (!acpi_is_root_bridge(phandle)) {
365		node = kzalloc(sizeof(struct acpi_handle_node), GFP_KERNEL);
366		if (!node)
367			goto out;
368
369		INIT_LIST_HEAD(&node->node);
370		node->handle = phandle;
371		list_add(&node->node, &device_list);
372
373		status = acpi_get_parent(phandle, &phandle);
374		if (ACPI_FAILURE(status))
375			goto out;
376	}
377
378	root = acpi_pci_find_root(phandle);
379	if (!root)
380		goto out;
381
382	pbus = root->bus;
383
384	/*
385	 * Now, walk back down the PCI device tree until we return to our
386	 * original handle. Assumes that everything between the PCI root
387	 * bridge and the device we're looking for must be a P2P bridge.
388	 */
389	list_for_each_entry(node, &device_list, node) {
390		acpi_handle hnd = node->handle;
391		status = acpi_evaluate_integer(hnd, "_ADR", NULL, &adr);
392		if (ACPI_FAILURE(status))
393			goto out;
394		dev = (adr >> 16) & 0xffff;
395		fn  = adr & 0xffff;
396
397		pdev = pci_get_slot(pbus, PCI_DEVFN(dev, fn));
398		if (!pdev || hnd == handle)
399			break;
400
401		pbus = pdev->subordinate;
402		pci_dev_put(pdev);
403	}
404out:
405	list_for_each_entry_safe(node, tmp, &device_list, node)
406		kfree(node);
407
408	return pdev;
409}
410EXPORT_SYMBOL_GPL(acpi_get_pci_dev);
411
412/**
413 * acpi_pci_osc_control_set - commit requested control to Firmware
414 * @handle: acpi_handle for the target ACPI object
415 * @flags: driver's requested control bits
416 *
417 * Attempt to take control from Firmware on requested control bits.
418 **/
419acpi_status acpi_pci_osc_control_set(acpi_handle handle, u32 flags)
420{
421	acpi_status status;
422	u32 control_req, result, capbuf[3];
423	acpi_handle tmp;
424	struct acpi_pci_root *root;
425
426	status = acpi_get_handle(handle, "_OSC", &tmp);
427	if (ACPI_FAILURE(status))
428		return status;
429
430	control_req = (flags & OSC_CONTROL_MASKS);
431	if (!control_req)
432		return AE_TYPE;
433
434	root = acpi_pci_find_root(handle);
435	if (!root)
436		return AE_NOT_EXIST;
437
438	mutex_lock(&osc_lock);
439	/* No need to evaluate _OSC if the control was already granted. */
440	if ((root->osc_control_set & control_req) == control_req)
441		goto out;
442
443	/* Need to query controls first before requesting them */
444	if (!root->osc_queried) {
445		status = acpi_pci_query_osc(root, root->osc_support_set);
446		if (ACPI_FAILURE(status))
447			goto out;
448	}
449	if ((root->osc_control_qry & control_req) != control_req) {
450		printk(KERN_DEBUG
451		       "Firmware did not grant requested _OSC control\n");
452		status = AE_SUPPORT;
453		goto out;
454	}
455
456	capbuf[OSC_QUERY_TYPE] = 0;
457	capbuf[OSC_SUPPORT_TYPE] = root->osc_support_set;
458	capbuf[OSC_CONTROL_TYPE] = root->osc_control_set | control_req;
459	status = acpi_pci_run_osc(handle, capbuf, &result);
460	if (ACPI_SUCCESS(status))
461		root->osc_control_set = result;
462out:
463	mutex_unlock(&osc_lock);
464	return status;
465}
466EXPORT_SYMBOL(acpi_pci_osc_control_set);
467
468static int __devinit acpi_pci_root_add(struct acpi_device *device)
469{
470	unsigned long long segment, bus;
471	acpi_status status;
472	int result;
473	struct acpi_pci_root *root;
474	acpi_handle handle;
475	struct acpi_device *child;
476	u32 flags, base_flags;
477
478	segment = 0;
479	status = acpi_evaluate_integer(device->handle, METHOD_NAME__SEG, NULL,
480				       &segment);
481	if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
482		printk(KERN_ERR PREFIX "can't evaluate _SEG\n");
483		return -ENODEV;
484	}
485
486	/* Check _CRS first, then _BBN.  If no _BBN, default to zero. */
487	bus = 0;
488	status = try_get_root_bridge_busnr(device->handle, &bus);
489	if (ACPI_FAILURE(status)) {
490		status = acpi_evaluate_integer(device->handle, METHOD_NAME__BBN,					       NULL, &bus);
491		if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
492			printk(KERN_ERR PREFIX
493			     "no bus number in _CRS and can't evaluate _BBN\n");
494			return -ENODEV;
495		}
496	}
497
498	root = kzalloc(sizeof(struct acpi_pci_root), GFP_KERNEL);
499	if (!root)
500		return -ENOMEM;
501
502	INIT_LIST_HEAD(&root->node);
503	root->device = device;
504	root->segment = segment & 0xFFFF;
505	root->bus_nr = bus & 0xFF;
506	strcpy(acpi_device_name(device), ACPI_PCI_ROOT_DEVICE_NAME);
507	strcpy(acpi_device_class(device), ACPI_PCI_ROOT_CLASS);
508	device->driver_data = root;
509
510	/*
511	 * All supported architectures that use ACPI have support for
512	 * PCI domains, so we indicate this in _OSC support capabilities.
513	 */
514	flags = base_flags = OSC_PCI_SEGMENT_GROUPS_SUPPORT;
515	acpi_pci_osc_support(root, flags);
516
517	/*
518	 * TBD: Need PCI interface for enumeration/configuration of roots.
519	 */
520
521	/* TBD: Locking */
522	list_add_tail(&root->node, &acpi_pci_roots);
523
524	printk(KERN_INFO PREFIX "%s [%s] (%04x:%02x)\n",
525	       acpi_device_name(device), acpi_device_bid(device),
526	       root->segment, root->bus_nr);
527
528	/*
529	 * Scan the Root Bridge
530	 * --------------------
531	 * Must do this prior to any attempt to bind the root device, as the
532	 * PCI namespace does not get created until this call is made (and
533	 * thus the root bridge's pci_dev does not exist).
534	 */
535	root->bus = pci_acpi_scan_root(device, segment, bus);
536	if (!root->bus) {
537		printk(KERN_ERR PREFIX
538			    "Bus %04x:%02x not present in PCI namespace\n",
539			    root->segment, root->bus_nr);
540		result = -ENODEV;
541		goto end;
542	}
543
544	/*
545	 * Attach ACPI-PCI Context
546	 * -----------------------
547	 * Thus binding the ACPI and PCI devices.
548	 */
549	result = acpi_pci_bind_root(device);
550	if (result)
551		goto end;
552
553	/*
554	 * PCI Routing Table
555	 * -----------------
556	 * Evaluate and parse _PRT, if exists.
557	 */
558	status = acpi_get_handle(device->handle, METHOD_NAME__PRT, &handle);
559	if (ACPI_SUCCESS(status))
560		result = acpi_pci_irq_add_prt(device->handle, root->bus);
561
562	/*
563	 * Scan and bind all _ADR-Based Devices
564	 */
565	list_for_each_entry(child, &device->children, node)
566		acpi_pci_bridge_scan(child);
567
568	/* Indicate support for various _OSC capabilities. */
569	if (pci_ext_cfg_avail(root->bus->self))
570		flags |= OSC_EXT_PCI_CONFIG_SUPPORT;
571	if (pcie_aspm_enabled())
572		flags |= OSC_ACTIVE_STATE_PWR_SUPPORT |
573			OSC_CLOCK_PWR_CAPABILITY_SUPPORT;
574	if (pci_msi_enabled())
575		flags |= OSC_MSI_SUPPORT;
576	if (flags != base_flags)
577		acpi_pci_osc_support(root, flags);
578
579	return 0;
580
581end:
582	if (!list_empty(&root->node))
583		list_del(&root->node);
584	kfree(root);
585	return result;
586}
587
588static int acpi_pci_root_start(struct acpi_device *device)
589{
590	struct acpi_pci_root *root = acpi_driver_data(device);
591
592	pci_bus_add_devices(root->bus);
593	return 0;
594}
595
596static int acpi_pci_root_remove(struct acpi_device *device, int type)
597{
598	struct acpi_pci_root *root = acpi_driver_data(device);
599
600	kfree(root);
601	return 0;
602}
603
604static int __init acpi_pci_root_init(void)
605{
606	if (acpi_pci_disabled)
607		return 0;
608
609	if (acpi_bus_register_driver(&acpi_pci_root_driver) < 0)
610		return -ENODEV;
611
612	return 0;
613}
614
615subsys_initcall(acpi_pci_root_init);
616