xref: /linux/drivers/acpi/pci_root.c (revision b0148a98ec5151fec82064d95f11eb9efbc628ea)
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
39 ACPI_MODULE_NAME("pci_root")
40 #define ACPI_PCI_ROOT_CLASS		"pci_bridge"
41 #define ACPI_PCI_ROOT_HID		"PNP0A03"
42 #define ACPI_PCI_ROOT_DRIVER_NAME	"ACPI PCI Root Bridge Driver"
43 #define ACPI_PCI_ROOT_DEVICE_NAME	"PCI Root Bridge"
44 static int acpi_pci_root_add(struct acpi_device *device);
45 static int acpi_pci_root_remove(struct acpi_device *device, int type);
46 static int acpi_pci_root_start(struct acpi_device *device);
47 
48 static struct acpi_driver acpi_pci_root_driver = {
49 	.name = ACPI_PCI_ROOT_DRIVER_NAME,
50 	.class = ACPI_PCI_ROOT_CLASS,
51 	.ids = ACPI_PCI_ROOT_HID,
52 	.ops = {
53 		.add = acpi_pci_root_add,
54 		.remove = acpi_pci_root_remove,
55 		.start = acpi_pci_root_start,
56 		},
57 };
58 
59 struct acpi_pci_root {
60 	struct list_head node;
61 	struct acpi_device * device;
62 	struct acpi_pci_id id;
63 	struct pci_bus *bus;
64 };
65 
66 static LIST_HEAD(acpi_pci_roots);
67 
68 static struct acpi_pci_driver *sub_driver;
69 
70 int acpi_pci_register_driver(struct acpi_pci_driver *driver)
71 {
72 	int n = 0;
73 	struct list_head *entry;
74 
75 	struct acpi_pci_driver **pptr = &sub_driver;
76 	while (*pptr)
77 		pptr = &(*pptr)->next;
78 	*pptr = driver;
79 
80 	if (!driver->add)
81 		return 0;
82 
83 	list_for_each(entry, &acpi_pci_roots) {
84 		struct acpi_pci_root *root;
85 		root = list_entry(entry, struct acpi_pci_root, 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 list_head *entry;
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, &acpi_pci_roots) {
112 		struct acpi_pci_root *root;
113 		root = list_entry(entry, struct acpi_pci_root, node);
114 		driver->remove(root->device->handle);
115 	}
116 }
117 
118 EXPORT_SYMBOL(acpi_pci_unregister_driver);
119 
120 acpi_handle acpi_get_pci_rootbridge_handle(unsigned int seg, unsigned int bus)
121 {
122 	struct acpi_pci_root *tmp;
123 
124 	list_for_each_entry(tmp, &acpi_pci_roots, node) {
125 		if ((tmp->id.segment == (u16) seg) && (tmp->id.bus == (u16) bus))
126 			return tmp->device->handle;
127 	}
128 	return NULL;
129 }
130 
131 EXPORT_SYMBOL_GPL(acpi_get_pci_rootbridge_handle);
132 
133 static acpi_status
134 get_root_bridge_busnr_callback(struct acpi_resource *resource, void *data)
135 {
136 	int *busnr = data;
137 	struct acpi_resource_address64 address;
138 
139 	if (resource->type != ACPI_RESOURCE_TYPE_ADDRESS16 &&
140 	    resource->type != ACPI_RESOURCE_TYPE_ADDRESS32 &&
141 	    resource->type != ACPI_RESOURCE_TYPE_ADDRESS64)
142 		return AE_OK;
143 
144 	acpi_resource_to_address64(resource, &address);
145 	if ((address.address_length > 0) &&
146 	    (address.resource_type == ACPI_BUS_NUMBER_RANGE))
147 		*busnr = address.minimum;
148 
149 	return AE_OK;
150 }
151 
152 static acpi_status try_get_root_bridge_busnr(acpi_handle handle, int *busnum)
153 {
154 	acpi_status status;
155 
156 	*busnum = -1;
157 	status =
158 	    acpi_walk_resources(handle, METHOD_NAME__CRS,
159 				get_root_bridge_busnr_callback, busnum);
160 	if (ACPI_FAILURE(status))
161 		return status;
162 	/* Check if we really get a bus number from _CRS */
163 	if (*busnum == -1)
164 		return AE_ERROR;
165 	return AE_OK;
166 }
167 
168 static void acpi_pci_bridge_scan(struct acpi_device *device)
169 {
170 	int status;
171 	struct acpi_device *child = NULL;
172 
173 	if (device->flags.bus_address)
174 		if (device->parent && device->parent->ops.bind) {
175 			status = device->parent->ops.bind(device);
176 			if (!status) {
177 				list_for_each_entry(child, &device->children, node)
178 					acpi_pci_bridge_scan(child);
179 			}
180 		}
181 }
182 
183 static int acpi_pci_root_add(struct acpi_device *device)
184 {
185 	int result = 0;
186 	struct acpi_pci_root *root = NULL;
187 	struct acpi_pci_root *tmp;
188 	acpi_status status = AE_OK;
189 	unsigned long value = 0;
190 	acpi_handle handle = NULL;
191 	struct acpi_device *child;
192 
193 
194 	if (!device)
195 		return -EINVAL;
196 
197 	root = kzalloc(sizeof(struct acpi_pci_root), GFP_KERNEL);
198 	if (!root)
199 		return -ENOMEM;
200 	INIT_LIST_HEAD(&root->node);
201 
202 	root->device = device;
203 	strcpy(acpi_device_name(device), ACPI_PCI_ROOT_DEVICE_NAME);
204 	strcpy(acpi_device_class(device), ACPI_PCI_ROOT_CLASS);
205 	acpi_driver_data(device) = root;
206 
207 	device->ops.bind = acpi_pci_bind;
208 
209 	/*
210 	 * Segment
211 	 * -------
212 	 * Obtained via _SEG, if exists, otherwise assumed to be zero (0).
213 	 */
214 	status = acpi_evaluate_integer(device->handle, METHOD_NAME__SEG, NULL,
215 				       &value);
216 	switch (status) {
217 	case AE_OK:
218 		root->id.segment = (u16) value;
219 		break;
220 	case AE_NOT_FOUND:
221 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
222 				  "Assuming segment 0 (no _SEG)\n"));
223 		root->id.segment = 0;
224 		break;
225 	default:
226 		ACPI_EXCEPTION((AE_INFO, status, "Evaluating _SEG"));
227 		result = -ENODEV;
228 		goto end;
229 	}
230 
231 	/*
232 	 * Bus
233 	 * ---
234 	 * Obtained via _BBN, if exists, otherwise assumed to be zero (0).
235 	 */
236 	status = acpi_evaluate_integer(device->handle, METHOD_NAME__BBN, NULL,
237 				       &value);
238 	switch (status) {
239 	case AE_OK:
240 		root->id.bus = (u16) value;
241 		break;
242 	case AE_NOT_FOUND:
243 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Assuming bus 0 (no _BBN)\n"));
244 		root->id.bus = 0;
245 		break;
246 	default:
247 		ACPI_EXCEPTION((AE_INFO, status, "Evaluating _BBN"));
248 		result = -ENODEV;
249 		goto end;
250 	}
251 
252 	/* Some systems have wrong _BBN */
253 	list_for_each_entry(tmp, &acpi_pci_roots, node) {
254 		if ((tmp->id.segment == root->id.segment)
255 		    && (tmp->id.bus == root->id.bus)) {
256 			int bus = 0;
257 			acpi_status status;
258 
259 			printk(KERN_ERR PREFIX
260 				    "Wrong _BBN value, reboot"
261 				    " and use option 'pci=noacpi'\n");
262 
263 			status = try_get_root_bridge_busnr(device->handle, &bus);
264 			if (ACPI_FAILURE(status))
265 				break;
266 			if (bus != root->id.bus) {
267 				printk(KERN_INFO PREFIX
268 				       "PCI _CRS %d overrides _BBN 0\n", bus);
269 				root->id.bus = bus;
270 			}
271 			break;
272 		}
273 	}
274 	/*
275 	 * Device & Function
276 	 * -----------------
277 	 * Obtained from _ADR (which has already been evaluated for us).
278 	 */
279 	root->id.device = device->pnp.bus_address >> 16;
280 	root->id.function = device->pnp.bus_address & 0xFFFF;
281 
282 	/*
283 	 * TBD: Need PCI interface for enumeration/configuration of roots.
284 	 */
285 
286 	/* TBD: Locking */
287 	list_add_tail(&root->node, &acpi_pci_roots);
288 
289 	printk(KERN_INFO PREFIX "%s [%s] (%04x:%02x)\n",
290 	       acpi_device_name(device), acpi_device_bid(device),
291 	       root->id.segment, root->id.bus);
292 
293 	/*
294 	 * Scan the Root Bridge
295 	 * --------------------
296 	 * Must do this prior to any attempt to bind the root device, as the
297 	 * PCI namespace does not get created until this call is made (and
298 	 * thus the root bridge's pci_dev does not exist).
299 	 */
300 	root->bus = pci_acpi_scan_root(device, root->id.segment, root->id.bus);
301 	if (!root->bus) {
302 		printk(KERN_ERR PREFIX
303 			    "Bus %04x:%02x not present in PCI namespace\n",
304 			    root->id.segment, root->id.bus);
305 		result = -ENODEV;
306 		goto end;
307 	}
308 
309 	/*
310 	 * Attach ACPI-PCI Context
311 	 * -----------------------
312 	 * Thus binding the ACPI and PCI devices.
313 	 */
314 	result = acpi_pci_bind_root(device, &root->id, root->bus);
315 	if (result)
316 		goto end;
317 
318 	/*
319 	 * PCI Routing Table
320 	 * -----------------
321 	 * Evaluate and parse _PRT, if exists.
322 	 */
323 	status = acpi_get_handle(device->handle, METHOD_NAME__PRT, &handle);
324 	if (ACPI_SUCCESS(status))
325 		result = acpi_pci_irq_add_prt(device->handle, root->id.segment,
326 					      root->id.bus);
327 
328 	/*
329 	 * Scan and bind all _ADR-Based Devices
330 	 */
331 	list_for_each_entry(child, &device->children, node)
332 		acpi_pci_bridge_scan(child);
333 
334       end:
335 	if (result) {
336 		if (!list_empty(&root->node))
337 			list_del(&root->node);
338 		kfree(root);
339 	}
340 
341 	return result;
342 }
343 
344 static int acpi_pci_root_start(struct acpi_device *device)
345 {
346 	struct acpi_pci_root *root;
347 
348 
349 	list_for_each_entry(root, &acpi_pci_roots, node) {
350 		if (root->device == device) {
351 			pci_bus_add_devices(root->bus);
352 			return 0;
353 		}
354 	}
355 	return -ENODEV;
356 }
357 
358 static int acpi_pci_root_remove(struct acpi_device *device, int type)
359 {
360 	struct acpi_pci_root *root = NULL;
361 
362 
363 	if (!device || !acpi_driver_data(device))
364 		return -EINVAL;
365 
366 	root = acpi_driver_data(device);
367 
368 	kfree(root);
369 
370 	return 0;
371 }
372 
373 static int __init acpi_pci_root_init(void)
374 {
375 
376 	if (acpi_pci_disabled)
377 		return 0;
378 
379 	/* DEBUG:
380 	   acpi_dbg_layer = ACPI_PCI_COMPONENT;
381 	   acpi_dbg_level = 0xFFFFFFFF;
382 	 */
383 
384 	if (acpi_bus_register_driver(&acpi_pci_root_driver) < 0)
385 		return -ENODEV;
386 
387 	return 0;
388 }
389 
390 subsys_initcall(acpi_pci_root_init);
391