xref: /linux/drivers/acpi/pci_root.c (revision d67b569f5f620c0fb95d5212642746b7ba9d29e4)
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 
39 #define _COMPONENT		ACPI_PCI_COMPONENT
40 ACPI_MODULE_NAME		("pci_root")
41 
42 #define ACPI_PCI_ROOT_CLASS		"pci_bridge"
43 #define ACPI_PCI_ROOT_HID		"PNP0A03"
44 #define ACPI_PCI_ROOT_DRIVER_NAME	"ACPI PCI Root Bridge Driver"
45 #define ACPI_PCI_ROOT_DEVICE_NAME	"PCI Root Bridge"
46 
47 static int acpi_pci_root_add (struct acpi_device *device);
48 static int acpi_pci_root_remove (struct acpi_device *device, int type);
49 static int acpi_pci_root_start (struct acpi_device *device);
50 
51 static struct acpi_driver acpi_pci_root_driver = {
52 	.name =		ACPI_PCI_ROOT_DRIVER_NAME,
53 	.class =	ACPI_PCI_ROOT_CLASS,
54 	.ids =		ACPI_PCI_ROOT_HID,
55 	.ops =		{
56 				.add =    acpi_pci_root_add,
57 				.remove = acpi_pci_root_remove,
58 				.start =  acpi_pci_root_start,
59 			},
60 };
61 
62 struct acpi_pci_root {
63 	struct list_head	node;
64 	acpi_handle		handle;
65 	struct acpi_pci_id	id;
66 	struct pci_bus		*bus;
67 };
68 
69 static LIST_HEAD(acpi_pci_roots);
70 
71 static struct acpi_pci_driver *sub_driver;
72 
73 int acpi_pci_register_driver(struct acpi_pci_driver *driver)
74 {
75 	int n = 0;
76 	struct list_head *entry;
77 
78 	struct acpi_pci_driver **pptr = &sub_driver;
79 	while (*pptr)
80 		pptr = &(*pptr)->next;
81 	*pptr = driver;
82 
83 	if (!driver->add)
84 		return 0;
85 
86 	list_for_each(entry, &acpi_pci_roots) {
87 		struct acpi_pci_root *root;
88 		root = list_entry(entry, struct acpi_pci_root, node);
89 		driver->add(root->handle);
90 		n++;
91 	}
92 
93 	return n;
94 }
95 EXPORT_SYMBOL(acpi_pci_register_driver);
96 
97 void acpi_pci_unregister_driver(struct acpi_pci_driver *driver)
98 {
99 	struct list_head *entry;
100 
101 	struct acpi_pci_driver **pptr = &sub_driver;
102 	while (*pptr) {
103 		if (*pptr != driver)
104 			continue;
105 		*pptr = (*pptr)->next;
106 		break;
107 	}
108 
109 	if (!driver->remove)
110 		return;
111 
112 	list_for_each(entry, &acpi_pci_roots) {
113 		struct acpi_pci_root *root;
114 		root = list_entry(entry, struct acpi_pci_root, node);
115 		driver->remove(root->handle);
116 	}
117 }
118 EXPORT_SYMBOL(acpi_pci_unregister_driver);
119 
120 static acpi_status
121 get_root_bridge_busnr_callback (struct acpi_resource *resource, void *data)
122 {
123 	int *busnr = (int *)data;
124 	struct acpi_resource_address64 address;
125 
126 	if (resource->id != ACPI_RSTYPE_ADDRESS16 &&
127 	    resource->id != ACPI_RSTYPE_ADDRESS32 &&
128 	    resource->id != ACPI_RSTYPE_ADDRESS64)
129 		return AE_OK;
130 
131 	acpi_resource_to_address64(resource, &address);
132 	if ((address.address_length > 0) &&
133 	   (address.resource_type == ACPI_BUS_NUMBER_RANGE))
134 		*busnr = address.min_address_range;
135 
136 	return AE_OK;
137 }
138 
139 static acpi_status
140 try_get_root_bridge_busnr(acpi_handle handle, int *busnum)
141 {
142 	acpi_status status;
143 
144 	*busnum = -1;
145 	status = acpi_walk_resources(handle, METHOD_NAME__CRS, get_root_bridge_busnr_callback, busnum);
146 	if (ACPI_FAILURE(status))
147 		return status;
148 	/* Check if we really get a bus number from _CRS */
149 	if (*busnum == -1)
150 		return AE_ERROR;
151 	return AE_OK;
152 }
153 
154 static int
155 acpi_pci_root_add (
156 	struct acpi_device	*device)
157 {
158 	int			result = 0;
159 	struct acpi_pci_root	*root = NULL;
160 	struct acpi_pci_root	*tmp;
161 	acpi_status		status = AE_OK;
162 	unsigned long		value = 0;
163 	acpi_handle		handle = NULL;
164 
165 	ACPI_FUNCTION_TRACE("acpi_pci_root_add");
166 
167 	if (!device)
168 		return_VALUE(-EINVAL);
169 
170 	root = kmalloc(sizeof(struct acpi_pci_root), GFP_KERNEL);
171 	if (!root)
172 		return_VALUE(-ENOMEM);
173 	memset(root, 0, sizeof(struct acpi_pci_root));
174 	INIT_LIST_HEAD(&root->node);
175 
176 	root->handle = device->handle;
177 	strcpy(acpi_device_name(device), ACPI_PCI_ROOT_DEVICE_NAME);
178 	strcpy(acpi_device_class(device), ACPI_PCI_ROOT_CLASS);
179 	acpi_driver_data(device) = root;
180 
181 	/*
182 	 * TBD: Doesn't the bus driver automatically set this?
183 	 */
184 	device->ops.bind = acpi_pci_bind;
185 
186 	/*
187 	 * Segment
188 	 * -------
189 	 * Obtained via _SEG, if exists, otherwise assumed to be zero (0).
190 	 */
191 	status = acpi_evaluate_integer(root->handle, METHOD_NAME__SEG, NULL,
192 		&value);
193 	switch (status) {
194 	case AE_OK:
195 		root->id.segment = (u16) value;
196 		break;
197 	case AE_NOT_FOUND:
198 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
199 			"Assuming segment 0 (no _SEG)\n"));
200 		root->id.segment = 0;
201 		break;
202 	default:
203 		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error evaluating _SEG\n"));
204 		result = -ENODEV;
205 		goto end;
206 	}
207 
208 	/*
209 	 * Bus
210 	 * ---
211 	 * Obtained via _BBN, if exists, otherwise assumed to be zero (0).
212 	 */
213 	status = acpi_evaluate_integer(root->handle, METHOD_NAME__BBN, NULL,
214 		&value);
215 	switch (status) {
216 	case AE_OK:
217 		root->id.bus = (u16) value;
218 		break;
219 	case AE_NOT_FOUND:
220 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Assuming bus 0 (no _BBN)\n"));
221 		root->id.bus = 0;
222 		break;
223 	default:
224 		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error evaluating _BBN\n"));
225 		result = -ENODEV;
226 		goto end;
227 	}
228 
229 	/* Some systems have wrong _BBN */
230 	list_for_each_entry(tmp, &acpi_pci_roots, node) {
231 		if ((tmp->id.segment == root->id.segment)
232 				&& (tmp->id.bus == root->id.bus)) {
233 			int bus = 0;
234 			acpi_status status;
235 
236 			ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
237 				"Wrong _BBN value, please reboot and using option 'pci=noacpi'\n"));
238 
239 			status = try_get_root_bridge_busnr(root->handle, &bus);
240 			if (ACPI_FAILURE(status))
241 				break;
242 			if (bus != root->id.bus) {
243 				printk(KERN_INFO PREFIX "PCI _CRS %d overrides _BBN 0\n", bus);
244 				root->id.bus = bus;
245 			}
246 			break;
247 		}
248 	}
249 	/*
250 	 * Device & Function
251 	 * -----------------
252 	 * Obtained from _ADR (which has already been evaluated for us).
253 	 */
254 	root->id.device = device->pnp.bus_address >> 16;
255 	root->id.function = device->pnp.bus_address & 0xFFFF;
256 
257 	/*
258 	 * TBD: Need PCI interface for enumeration/configuration of roots.
259 	 */
260 
261  	/* TBD: Locking */
262  	list_add_tail(&root->node, &acpi_pci_roots);
263 
264 	printk(KERN_INFO PREFIX "%s [%s] (%04x:%02x)\n",
265 		acpi_device_name(device), acpi_device_bid(device),
266 		root->id.segment, root->id.bus);
267 
268 	/*
269 	 * Scan the Root Bridge
270 	 * --------------------
271 	 * Must do this prior to any attempt to bind the root device, as the
272 	 * PCI namespace does not get created until this call is made (and
273 	 * thus the root bridge's pci_dev does not exist).
274 	 */
275 	root->bus = pci_acpi_scan_root(device, root->id.segment, root->id.bus);
276 	if (!root->bus) {
277 		ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
278 			"Bus %04x:%02x not present in PCI namespace\n",
279 			root->id.segment, root->id.bus));
280 		result = -ENODEV;
281 		goto end;
282 	}
283 
284 	/*
285 	 * Attach ACPI-PCI Context
286 	 * -----------------------
287 	 * Thus binding the ACPI and PCI devices.
288 	 */
289 	result = acpi_pci_bind_root(device, &root->id, root->bus);
290 	if (result)
291 		goto end;
292 
293 	/*
294 	 * PCI Routing Table
295 	 * -----------------
296 	 * Evaluate and parse _PRT, if exists.
297 	 */
298 	status = acpi_get_handle(root->handle, METHOD_NAME__PRT, &handle);
299 	if (ACPI_SUCCESS(status))
300 		result = acpi_pci_irq_add_prt(root->handle, root->id.segment,
301 			root->id.bus);
302 
303 end:
304 	if (result) {
305 		if (!list_empty(&root->node))
306 			list_del(&root->node);
307 		kfree(root);
308 	}
309 
310 	return_VALUE(result);
311 }
312 
313 static int
314 acpi_pci_root_start (
315 	struct acpi_device	*device)
316 {
317 	struct acpi_pci_root	*root;
318 
319 	ACPI_FUNCTION_TRACE("acpi_pci_root_start");
320 
321 	list_for_each_entry(root, &acpi_pci_roots, node) {
322 		if (root->handle == device->handle) {
323 			pci_bus_add_devices(root->bus);
324 			return_VALUE(0);
325 		}
326 	}
327 	return_VALUE(-ENODEV);
328 }
329 
330 static int
331 acpi_pci_root_remove (
332 	struct acpi_device	*device,
333 	int			type)
334 {
335 	struct acpi_pci_root	*root = NULL;
336 
337 	ACPI_FUNCTION_TRACE("acpi_pci_root_remove");
338 
339 	if (!device || !acpi_driver_data(device))
340 		return_VALUE(-EINVAL);
341 
342 	root = (struct acpi_pci_root *) acpi_driver_data(device);
343 
344 	kfree(root);
345 
346 	return_VALUE(0);
347 }
348 
349 
350 static int __init acpi_pci_root_init (void)
351 {
352 	ACPI_FUNCTION_TRACE("acpi_pci_root_init");
353 
354 	if (acpi_pci_disabled)
355 		return_VALUE(0);
356 
357 	/* DEBUG:
358 	acpi_dbg_layer = ACPI_PCI_COMPONENT;
359 	acpi_dbg_level = 0xFFFFFFFF;
360 	 */
361 
362 	if (acpi_bus_register_driver(&acpi_pci_root_driver) < 0)
363 		return_VALUE(-ENODEV);
364 
365 	return_VALUE(0);
366 }
367 
368 subsys_initcall(acpi_pci_root_init);
369 
370