pci_root.c revision db89b4f0dbab837d0f3de2c3e9427a8d5393afa3 
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/acpi.h>
35#include <acpi/acpi_bus.h>
36#include <acpi/acpi_drivers.h>
37
38#define _COMPONENT		ACPI_PCI_COMPONENT
39ACPI_MODULE_NAME("pci_root");
40#define ACPI_PCI_ROOT_CLASS		"pci_bridge"
41#define ACPI_PCI_ROOT_DEVICE_NAME	"PCI Root Bridge"
42static int acpi_pci_root_add(struct acpi_device *device);
43static int acpi_pci_root_remove(struct acpi_device *device, int type);
44static int acpi_pci_root_start(struct acpi_device *device);
45
46static struct acpi_device_id root_device_ids[] = {
47	{"PNP0A03", 0},
48	{"", 0},
49};
50MODULE_DEVICE_TABLE(acpi, root_device_ids);
51
52static struct acpi_driver acpi_pci_root_driver = {
53	.name = "pci_root",
54	.class = ACPI_PCI_ROOT_CLASS,
55	.ids = root_device_ids,
56	.ops = {
57		.add = acpi_pci_root_add,
58		.remove = acpi_pci_root_remove,
59		.start = acpi_pci_root_start,
60		},
61};
62
63struct acpi_pci_root {
64	struct list_head node;
65	struct acpi_device * device;
66	struct acpi_pci_id id;
67	struct pci_bus *bus;
68};
69
70static LIST_HEAD(acpi_pci_roots);
71
72static struct acpi_pci_driver *sub_driver;
73
74int acpi_pci_register_driver(struct acpi_pci_driver *driver)
75{
76	int n = 0;
77	struct list_head *entry;
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, &acpi_pci_roots) {
88		struct acpi_pci_root *root;
89		root = list_entry(entry, struct acpi_pci_root, node);
90		driver->add(root->device->handle);
91		n++;
92	}
93
94	return n;
95}
96
97EXPORT_SYMBOL(acpi_pci_register_driver);
98
99void acpi_pci_unregister_driver(struct acpi_pci_driver *driver)
100{
101	struct list_head *entry;
102
103	struct acpi_pci_driver **pptr = &sub_driver;
104	while (*pptr) {
105		if (*pptr == driver)
106			break;
107		pptr = &(*pptr)->next;
108	}
109	BUG_ON(!*pptr);
110	*pptr = (*pptr)->next;
111
112	if (!driver->remove)
113		return;
114
115	list_for_each(entry, &acpi_pci_roots) {
116		struct acpi_pci_root *root;
117		root = list_entry(entry, struct acpi_pci_root, node);
118		driver->remove(root->device->handle);
119	}
120}
121
122EXPORT_SYMBOL(acpi_pci_unregister_driver);
123
124acpi_handle acpi_get_pci_rootbridge_handle(unsigned int seg, unsigned int bus)
125{
126	struct acpi_pci_root *tmp;
127
128	list_for_each_entry(tmp, &acpi_pci_roots, node) {
129		if ((tmp->id.segment == (u16) seg) && (tmp->id.bus == (u16) bus))
130			return tmp->device->handle;
131	}
132	return NULL;
133}
134
135EXPORT_SYMBOL_GPL(acpi_get_pci_rootbridge_handle);
136
137static acpi_status
138get_root_bridge_busnr_callback(struct acpi_resource *resource, void *data)
139{
140	int *busnr = data;
141	struct acpi_resource_address64 address;
142
143	if (resource->type != ACPI_RESOURCE_TYPE_ADDRESS16 &&
144	    resource->type != ACPI_RESOURCE_TYPE_ADDRESS32 &&
145	    resource->type != ACPI_RESOURCE_TYPE_ADDRESS64)
146		return AE_OK;
147
148	acpi_resource_to_address64(resource, &address);
149	if ((address.address_length > 0) &&
150	    (address.resource_type == ACPI_BUS_NUMBER_RANGE))
151		*busnr = address.minimum;
152
153	return AE_OK;
154}
155
156static acpi_status try_get_root_bridge_busnr(acpi_handle handle, int *busnum)
157{
158	acpi_status status;
159
160	*busnum = -1;
161	status =
162	    acpi_walk_resources(handle, METHOD_NAME__CRS,
163				get_root_bridge_busnr_callback, busnum);
164	if (ACPI_FAILURE(status))
165		return status;
166	/* Check if we really get a bus number from _CRS */
167	if (*busnum == -1)
168		return AE_ERROR;
169	return AE_OK;
170}
171
172static void acpi_pci_bridge_scan(struct acpi_device *device)
173{
174	int status;
175	struct acpi_device *child = NULL;
176
177	if (device->flags.bus_address)
178		if (device->parent && device->parent->ops.bind) {
179			status = device->parent->ops.bind(device);
180			if (!status) {
181				list_for_each_entry(child, &device->children, node)
182					acpi_pci_bridge_scan(child);
183			}
184		}
185}
186
187static int __devinit acpi_pci_root_add(struct acpi_device *device)
188{
189	int result = 0;
190	struct acpi_pci_root *root = NULL;
191	struct acpi_pci_root *tmp;
192	acpi_status status = AE_OK;
193	unsigned long value = 0;
194	acpi_handle handle = NULL;
195	struct acpi_device *child;
196
197
198	if (!device)
199		return -EINVAL;
200
201	root = kzalloc(sizeof(struct acpi_pci_root), GFP_KERNEL);
202	if (!root)
203		return -ENOMEM;
204	INIT_LIST_HEAD(&root->node);
205
206	root->device = device;
207	strcpy(acpi_device_name(device), ACPI_PCI_ROOT_DEVICE_NAME);
208	strcpy(acpi_device_class(device), ACPI_PCI_ROOT_CLASS);
209	device->driver_data = root;
210
211	device->ops.bind = acpi_pci_bind;
212
213	/*
214	 * Segment
215	 * -------
216	 * Obtained via _SEG, if exists, otherwise assumed to be zero (0).
217	 */
218	status = acpi_evaluate_integer(device->handle, METHOD_NAME__SEG, NULL,
219				       &value);
220	switch (status) {
221	case AE_OK:
222		root->id.segment = (u16) value;
223		break;
224	case AE_NOT_FOUND:
225		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
226				  "Assuming segment 0 (no _SEG)\n"));
227		root->id.segment = 0;
228		break;
229	default:
230		ACPI_EXCEPTION((AE_INFO, status, "Evaluating _SEG"));
231		result = -ENODEV;
232		goto end;
233	}
234
235	/*
236	 * Bus
237	 * ---
238	 * Obtained via _BBN, if exists, otherwise assumed to be zero (0).
239	 */
240	status = acpi_evaluate_integer(device->handle, METHOD_NAME__BBN, NULL,
241				       &value);
242	switch (status) {
243	case AE_OK:
244		root->id.bus = (u16) value;
245		break;
246	case AE_NOT_FOUND:
247		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Assuming bus 0 (no _BBN)\n"));
248		root->id.bus = 0;
249		break;
250	default:
251		ACPI_EXCEPTION((AE_INFO, status, "Evaluating _BBN"));
252		result = -ENODEV;
253		goto end;
254	}
255
256	/* Some systems have wrong _BBN */
257	list_for_each_entry(tmp, &acpi_pci_roots, node) {
258		if ((tmp->id.segment == root->id.segment)
259		    && (tmp->id.bus == root->id.bus)) {
260			int bus = 0;
261			acpi_status status;
262
263			printk(KERN_ERR PREFIX
264				    "Wrong _BBN value, reboot"
265				    " and use option 'pci=noacpi'\n");
266
267			status = try_get_root_bridge_busnr(device->handle, &bus);
268			if (ACPI_FAILURE(status))
269				break;
270			if (bus != root->id.bus) {
271				printk(KERN_INFO PREFIX
272				       "PCI _CRS %d overrides _BBN 0\n", bus);
273				root->id.bus = bus;
274			}
275			break;
276		}
277	}
278	/*
279	 * Device & Function
280	 * -----------------
281	 * Obtained from _ADR (which has already been evaluated for us).
282	 */
283	root->id.device = device->pnp.bus_address >> 16;
284	root->id.function = device->pnp.bus_address & 0xFFFF;
285
286	/*
287	 * TBD: Need PCI interface for enumeration/configuration of roots.
288	 */
289
290	/* TBD: Locking */
291	list_add_tail(&root->node, &acpi_pci_roots);
292
293	printk(KERN_INFO PREFIX "%s [%s] (%04x:%02x)\n",
294	       acpi_device_name(device), acpi_device_bid(device),
295	       root->id.segment, root->id.bus);
296
297	/*
298	 * Scan the Root Bridge
299	 * --------------------
300	 * Must do this prior to any attempt to bind the root device, as the
301	 * PCI namespace does not get created until this call is made (and
302	 * thus the root bridge's pci_dev does not exist).
303	 */
304	root->bus = pci_acpi_scan_root(device, root->id.segment, root->id.bus);
305	if (!root->bus) {
306		printk(KERN_ERR PREFIX
307			    "Bus %04x:%02x not present in PCI namespace\n",
308			    root->id.segment, root->id.bus);
309		result = -ENODEV;
310		goto end;
311	}
312
313	/*
314	 * Attach ACPI-PCI Context
315	 * -----------------------
316	 * Thus binding the ACPI and PCI devices.
317	 */
318	result = acpi_pci_bind_root(device, &root->id, root->bus);
319	if (result)
320		goto end;
321
322	/*
323	 * PCI Routing Table
324	 * -----------------
325	 * Evaluate and parse _PRT, if exists.
326	 */
327	status = acpi_get_handle(device->handle, METHOD_NAME__PRT, &handle);
328	if (ACPI_SUCCESS(status))
329		result = acpi_pci_irq_add_prt(device->handle, root->id.segment,
330					      root->id.bus);
331
332	/*
333	 * Scan and bind all _ADR-Based Devices
334	 */
335	list_for_each_entry(child, &device->children, node)
336		acpi_pci_bridge_scan(child);
337
338      end:
339	if (result) {
340		if (!list_empty(&root->node))
341			list_del(&root->node);
342		kfree(root);
343	}
344
345	return result;
346}
347
348static int acpi_pci_root_start(struct acpi_device *device)
349{
350	struct acpi_pci_root *root;
351
352
353	list_for_each_entry(root, &acpi_pci_roots, node) {
354		if (root->device == device) {
355			pci_bus_add_devices(root->bus);
356			return 0;
357		}
358	}
359	return -ENODEV;
360}
361
362static int acpi_pci_root_remove(struct acpi_device *device, int type)
363{
364	struct acpi_pci_root *root = NULL;
365
366
367	if (!device || !acpi_driver_data(device))
368		return -EINVAL;
369
370	root = acpi_driver_data(device);
371
372	kfree(root);
373
374	return 0;
375}
376
377static int __init acpi_pci_root_init(void)
378{
379
380	if (acpi_pci_disabled)
381		return 0;
382
383	/* DEBUG:
384	   acpi_dbg_layer = ACPI_PCI_COMPONENT;
385	   acpi_dbg_level = 0xFFFFFFFF;
386	 */
387
388	if (acpi_bus_register_driver(&acpi_pci_root_driver) < 0)
389		return -ENODEV;
390
391	return 0;
392}
393
394subsys_initcall(acpi_pci_root_init);
395