xref: /openbmc/linux/drivers/acpi/pci_root.c (revision 22246614) 
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_DEVICE_NAME	"PCI Root Bridge"
42 static int acpi_pci_root_add(struct acpi_device *device);
43 static int acpi_pci_root_remove(struct acpi_device *device, int type);
44 static int acpi_pci_root_start(struct acpi_device *device);
45 
46 static struct acpi_device_id root_device_ids[] = {
47 	{"PNP0A03", 0},
48 	{"", 0},
49 };
50 MODULE_DEVICE_TABLE(acpi, root_device_ids);
51 
52 static 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 
63 struct 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 
70 static LIST_HEAD(acpi_pci_roots);
71 
72 static struct acpi_pci_driver *sub_driver;
73 
74 int 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 
97 EXPORT_SYMBOL(acpi_pci_register_driver);
98 
99 void 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 
122 EXPORT_SYMBOL(acpi_pci_unregister_driver);
123 
124 acpi_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 
135 EXPORT_SYMBOL_GPL(acpi_get_pci_rootbridge_handle);
136 
137 static acpi_status
138 get_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 
156 static 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 
172 static 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 
187 static 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 	acpi_driver_data(device) = 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 
348 static 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 
362 static 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 
377 static 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 
394 subsys_initcall(acpi_pci_root_init);
395