xref: /openbmc/linux/drivers/acpi/pci_root.c (revision 82ced6fd) 
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
40 ACPI_MODULE_NAME("pci_root");
41 #define ACPI_PCI_ROOT_CLASS		"pci_bridge"
42 #define ACPI_PCI_ROOT_DEVICE_NAME	"PCI Root Bridge"
43 static int acpi_pci_root_add(struct acpi_device *device);
44 static int acpi_pci_root_remove(struct acpi_device *device, int type);
45 static int acpi_pci_root_start(struct acpi_device *device);
46 
47 static struct acpi_device_id root_device_ids[] = {
48 	{"PNP0A03", 0},
49 	{"", 0},
50 };
51 MODULE_DEVICE_TABLE(acpi, root_device_ids);
52 
53 static 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 
64 struct acpi_pci_root {
65 	struct list_head node;
66 	struct acpi_device * device;
67 	struct acpi_pci_id id;
68 	struct pci_bus *bus;
69 
70 	u32 osc_support_set;	/* _OSC state of support bits */
71 	u32 osc_control_set;	/* _OSC state of control bits */
72 	u32 osc_control_qry;	/* the latest _OSC query result */
73 
74 	u32 osc_queried:1;	/* has _OSC control been queried? */
75 };
76 
77 static LIST_HEAD(acpi_pci_roots);
78 
79 static struct acpi_pci_driver *sub_driver;
80 static DEFINE_MUTEX(osc_lock);
81 
82 int acpi_pci_register_driver(struct acpi_pci_driver *driver)
83 {
84 	int n = 0;
85 	struct list_head *entry;
86 
87 	struct acpi_pci_driver **pptr = &sub_driver;
88 	while (*pptr)
89 		pptr = &(*pptr)->next;
90 	*pptr = driver;
91 
92 	if (!driver->add)
93 		return 0;
94 
95 	list_for_each(entry, &acpi_pci_roots) {
96 		struct acpi_pci_root *root;
97 		root = list_entry(entry, struct acpi_pci_root, node);
98 		driver->add(root->device->handle);
99 		n++;
100 	}
101 
102 	return n;
103 }
104 
105 EXPORT_SYMBOL(acpi_pci_register_driver);
106 
107 void acpi_pci_unregister_driver(struct acpi_pci_driver *driver)
108 {
109 	struct list_head *entry;
110 
111 	struct acpi_pci_driver **pptr = &sub_driver;
112 	while (*pptr) {
113 		if (*pptr == driver)
114 			break;
115 		pptr = &(*pptr)->next;
116 	}
117 	BUG_ON(!*pptr);
118 	*pptr = (*pptr)->next;
119 
120 	if (!driver->remove)
121 		return;
122 
123 	list_for_each(entry, &acpi_pci_roots) {
124 		struct acpi_pci_root *root;
125 		root = list_entry(entry, struct acpi_pci_root, node);
126 		driver->remove(root->device->handle);
127 	}
128 }
129 
130 EXPORT_SYMBOL(acpi_pci_unregister_driver);
131 
132 acpi_handle acpi_get_pci_rootbridge_handle(unsigned int seg, unsigned int bus)
133 {
134 	struct acpi_pci_root *tmp;
135 
136 	list_for_each_entry(tmp, &acpi_pci_roots, node) {
137 		if ((tmp->id.segment == (u16) seg) && (tmp->id.bus == (u16) bus))
138 			return tmp->device->handle;
139 	}
140 	return NULL;
141 }
142 
143 EXPORT_SYMBOL_GPL(acpi_get_pci_rootbridge_handle);
144 
145 static acpi_status
146 get_root_bridge_busnr_callback(struct acpi_resource *resource, void *data)
147 {
148 	int *busnr = data;
149 	struct acpi_resource_address64 address;
150 
151 	if (resource->type != ACPI_RESOURCE_TYPE_ADDRESS16 &&
152 	    resource->type != ACPI_RESOURCE_TYPE_ADDRESS32 &&
153 	    resource->type != ACPI_RESOURCE_TYPE_ADDRESS64)
154 		return AE_OK;
155 
156 	acpi_resource_to_address64(resource, &address);
157 	if ((address.address_length > 0) &&
158 	    (address.resource_type == ACPI_BUS_NUMBER_RANGE))
159 		*busnr = address.minimum;
160 
161 	return AE_OK;
162 }
163 
164 static acpi_status try_get_root_bridge_busnr(acpi_handle handle, int *busnum)
165 {
166 	acpi_status status;
167 
168 	*busnum = -1;
169 	status =
170 	    acpi_walk_resources(handle, METHOD_NAME__CRS,
171 				get_root_bridge_busnr_callback, busnum);
172 	if (ACPI_FAILURE(status))
173 		return status;
174 	/* Check if we really get a bus number from _CRS */
175 	if (*busnum == -1)
176 		return AE_ERROR;
177 	return AE_OK;
178 }
179 
180 static void acpi_pci_bridge_scan(struct acpi_device *device)
181 {
182 	int status;
183 	struct acpi_device *child = NULL;
184 
185 	if (device->flags.bus_address)
186 		if (device->parent && device->parent->ops.bind) {
187 			status = device->parent->ops.bind(device);
188 			if (!status) {
189 				list_for_each_entry(child, &device->children, node)
190 					acpi_pci_bridge_scan(child);
191 			}
192 		}
193 }
194 
195 static u8 OSC_UUID[16] = {0x5B, 0x4D, 0xDB, 0x33, 0xF7, 0x1F, 0x1C, 0x40,
196 			  0x96, 0x57, 0x74, 0x41, 0xC0, 0x3D, 0xD7, 0x66};
197 
198 static acpi_status acpi_pci_run_osc(acpi_handle handle,
199 				    const u32 *capbuf, u32 *retval)
200 {
201 	acpi_status status;
202 	struct acpi_object_list input;
203 	union acpi_object in_params[4];
204 	struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL};
205 	union acpi_object *out_obj;
206 	u32 errors;
207 
208 	/* Setting up input parameters */
209 	input.count = 4;
210 	input.pointer = in_params;
211 	in_params[0].type 		= ACPI_TYPE_BUFFER;
212 	in_params[0].buffer.length 	= 16;
213 	in_params[0].buffer.pointer	= OSC_UUID;
214 	in_params[1].type 		= ACPI_TYPE_INTEGER;
215 	in_params[1].integer.value 	= 1;
216 	in_params[2].type 		= ACPI_TYPE_INTEGER;
217 	in_params[2].integer.value	= 3;
218 	in_params[3].type		= ACPI_TYPE_BUFFER;
219 	in_params[3].buffer.length 	= 12;
220 	in_params[3].buffer.pointer 	= (u8 *)capbuf;
221 
222 	status = acpi_evaluate_object(handle, "_OSC", &input, &output);
223 	if (ACPI_FAILURE(status))
224 		return status;
225 
226 	if (!output.length)
227 		return AE_NULL_OBJECT;
228 
229 	out_obj = output.pointer;
230 	if (out_obj->type != ACPI_TYPE_BUFFER) {
231 		printk(KERN_DEBUG "_OSC evaluation returned wrong type\n");
232 		status = AE_TYPE;
233 		goto out_kfree;
234 	}
235 	/* Need to ignore the bit0 in result code */
236 	errors = *((u32 *)out_obj->buffer.pointer) & ~(1 << 0);
237 	if (errors) {
238 		if (errors & OSC_REQUEST_ERROR)
239 			printk(KERN_DEBUG "_OSC request failed\n");
240 		if (errors & OSC_INVALID_UUID_ERROR)
241 			printk(KERN_DEBUG "_OSC invalid UUID\n");
242 		if (errors & OSC_INVALID_REVISION_ERROR)
243 			printk(KERN_DEBUG "_OSC invalid revision\n");
244 		if (errors & OSC_CAPABILITIES_MASK_ERROR) {
245 			if (capbuf[OSC_QUERY_TYPE] & OSC_QUERY_ENABLE)
246 				goto out_success;
247 			printk(KERN_DEBUG
248 			       "Firmware did not grant requested _OSC control\n");
249 			status = AE_SUPPORT;
250 			goto out_kfree;
251 		}
252 		status = AE_ERROR;
253 		goto out_kfree;
254 	}
255 out_success:
256 	*retval = *((u32 *)(out_obj->buffer.pointer + 8));
257 	status = AE_OK;
258 
259 out_kfree:
260 	kfree(output.pointer);
261 	return status;
262 }
263 
264 static acpi_status acpi_pci_query_osc(struct acpi_pci_root *root, u32 flags)
265 {
266 	acpi_status status;
267 	u32 support_set, result, capbuf[3];
268 
269 	/* do _OSC query for all possible controls */
270 	support_set = root->osc_support_set | (flags & OSC_SUPPORT_MASKS);
271 	capbuf[OSC_QUERY_TYPE] = OSC_QUERY_ENABLE;
272 	capbuf[OSC_SUPPORT_TYPE] = support_set;
273 	capbuf[OSC_CONTROL_TYPE] = OSC_CONTROL_MASKS;
274 
275 	status = acpi_pci_run_osc(root->device->handle, capbuf, &result);
276 	if (ACPI_SUCCESS(status)) {
277 		root->osc_support_set = support_set;
278 		root->osc_control_qry = result;
279 		root->osc_queried = 1;
280 	}
281 	return status;
282 }
283 
284 static acpi_status acpi_pci_osc_support(struct acpi_pci_root *root, u32 flags)
285 {
286 	acpi_status status;
287 	acpi_handle tmp;
288 
289 	status = acpi_get_handle(root->device->handle, "_OSC", &tmp);
290 	if (ACPI_FAILURE(status))
291 		return status;
292 	mutex_lock(&osc_lock);
293 	status = acpi_pci_query_osc(root, flags);
294 	mutex_unlock(&osc_lock);
295 	return status;
296 }
297 
298 static struct acpi_pci_root *acpi_pci_find_root(acpi_handle handle)
299 {
300 	struct acpi_pci_root *root;
301 	list_for_each_entry(root, &acpi_pci_roots, node) {
302 		if (root->device->handle == handle)
303 			return root;
304 	}
305 	return NULL;
306 }
307 
308 /**
309  * acpi_pci_osc_control_set - commit requested control to Firmware
310  * @handle: acpi_handle for the target ACPI object
311  * @flags: driver's requested control bits
312  *
313  * Attempt to take control from Firmware on requested control bits.
314  **/
315 acpi_status acpi_pci_osc_control_set(acpi_handle handle, u32 flags)
316 {
317 	acpi_status status;
318 	u32 control_req, result, capbuf[3];
319 	acpi_handle tmp;
320 	struct acpi_pci_root *root;
321 
322 	status = acpi_get_handle(handle, "_OSC", &tmp);
323 	if (ACPI_FAILURE(status))
324 		return status;
325 
326 	control_req = (flags & OSC_CONTROL_MASKS);
327 	if (!control_req)
328 		return AE_TYPE;
329 
330 	root = acpi_pci_find_root(handle);
331 	if (!root)
332 		return AE_NOT_EXIST;
333 
334 	mutex_lock(&osc_lock);
335 	/* No need to evaluate _OSC if the control was already granted. */
336 	if ((root->osc_control_set & control_req) == control_req)
337 		goto out;
338 
339 	/* Need to query controls first before requesting them */
340 	if (!root->osc_queried) {
341 		status = acpi_pci_query_osc(root, root->osc_support_set);
342 		if (ACPI_FAILURE(status))
343 			goto out;
344 	}
345 	if ((root->osc_control_qry & control_req) != control_req) {
346 		printk(KERN_DEBUG
347 		       "Firmware did not grant requested _OSC control\n");
348 		status = AE_SUPPORT;
349 		goto out;
350 	}
351 
352 	capbuf[OSC_QUERY_TYPE] = 0;
353 	capbuf[OSC_SUPPORT_TYPE] = root->osc_support_set;
354 	capbuf[OSC_CONTROL_TYPE] = root->osc_control_set | control_req;
355 	status = acpi_pci_run_osc(handle, capbuf, &result);
356 	if (ACPI_SUCCESS(status))
357 		root->osc_control_set = result;
358 out:
359 	mutex_unlock(&osc_lock);
360 	return status;
361 }
362 EXPORT_SYMBOL(acpi_pci_osc_control_set);
363 
364 static int __devinit acpi_pci_root_add(struct acpi_device *device)
365 {
366 	int result = 0;
367 	struct acpi_pci_root *root = NULL;
368 	struct acpi_pci_root *tmp;
369 	acpi_status status = AE_OK;
370 	unsigned long long value = 0;
371 	acpi_handle handle = NULL;
372 	struct acpi_device *child;
373 	u32 flags, base_flags;
374 
375 
376 	if (!device)
377 		return -EINVAL;
378 
379 	root = kzalloc(sizeof(struct acpi_pci_root), GFP_KERNEL);
380 	if (!root)
381 		return -ENOMEM;
382 	INIT_LIST_HEAD(&root->node);
383 
384 	root->device = device;
385 	strcpy(acpi_device_name(device), ACPI_PCI_ROOT_DEVICE_NAME);
386 	strcpy(acpi_device_class(device), ACPI_PCI_ROOT_CLASS);
387 	device->driver_data = root;
388 
389 	device->ops.bind = acpi_pci_bind;
390 
391 	/*
392 	 * All supported architectures that use ACPI have support for
393 	 * PCI domains, so we indicate this in _OSC support capabilities.
394 	 */
395 	flags = base_flags = OSC_PCI_SEGMENT_GROUPS_SUPPORT;
396 	acpi_pci_osc_support(root, flags);
397 
398 	/*
399 	 * Segment
400 	 * -------
401 	 * Obtained via _SEG, if exists, otherwise assumed to be zero (0).
402 	 */
403 	status = acpi_evaluate_integer(device->handle, METHOD_NAME__SEG, NULL,
404 				       &value);
405 	switch (status) {
406 	case AE_OK:
407 		root->id.segment = (u16) value;
408 		break;
409 	case AE_NOT_FOUND:
410 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
411 				  "Assuming segment 0 (no _SEG)\n"));
412 		root->id.segment = 0;
413 		break;
414 	default:
415 		ACPI_EXCEPTION((AE_INFO, status, "Evaluating _SEG"));
416 		result = -ENODEV;
417 		goto end;
418 	}
419 
420 	/*
421 	 * Bus
422 	 * ---
423 	 * Obtained via _BBN, if exists, otherwise assumed to be zero (0).
424 	 */
425 	status = acpi_evaluate_integer(device->handle, METHOD_NAME__BBN, NULL,
426 				       &value);
427 	switch (status) {
428 	case AE_OK:
429 		root->id.bus = (u16) value;
430 		break;
431 	case AE_NOT_FOUND:
432 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Assuming bus 0 (no _BBN)\n"));
433 		root->id.bus = 0;
434 		break;
435 	default:
436 		ACPI_EXCEPTION((AE_INFO, status, "Evaluating _BBN"));
437 		result = -ENODEV;
438 		goto end;
439 	}
440 
441 	/* Some systems have wrong _BBN */
442 	list_for_each_entry(tmp, &acpi_pci_roots, node) {
443 		if ((tmp->id.segment == root->id.segment)
444 		    && (tmp->id.bus == root->id.bus)) {
445 			int bus = 0;
446 			acpi_status status;
447 
448 			printk(KERN_ERR PREFIX
449 				    "Wrong _BBN value, reboot"
450 				    " and use option 'pci=noacpi'\n");
451 
452 			status = try_get_root_bridge_busnr(device->handle, &bus);
453 			if (ACPI_FAILURE(status))
454 				break;
455 			if (bus != root->id.bus) {
456 				printk(KERN_INFO PREFIX
457 				       "PCI _CRS %d overrides _BBN 0\n", bus);
458 				root->id.bus = bus;
459 			}
460 			break;
461 		}
462 	}
463 	/*
464 	 * Device & Function
465 	 * -----------------
466 	 * Obtained from _ADR (which has already been evaluated for us).
467 	 */
468 	root->id.device = device->pnp.bus_address >> 16;
469 	root->id.function = device->pnp.bus_address & 0xFFFF;
470 
471 	/*
472 	 * TBD: Need PCI interface for enumeration/configuration of roots.
473 	 */
474 
475 	/* TBD: Locking */
476 	list_add_tail(&root->node, &acpi_pci_roots);
477 
478 	printk(KERN_INFO PREFIX "%s [%s] (%04x:%02x)\n",
479 	       acpi_device_name(device), acpi_device_bid(device),
480 	       root->id.segment, root->id.bus);
481 
482 	/*
483 	 * Scan the Root Bridge
484 	 * --------------------
485 	 * Must do this prior to any attempt to bind the root device, as the
486 	 * PCI namespace does not get created until this call is made (and
487 	 * thus the root bridge's pci_dev does not exist).
488 	 */
489 	root->bus = pci_acpi_scan_root(device, root->id.segment, root->id.bus);
490 	if (!root->bus) {
491 		printk(KERN_ERR PREFIX
492 			    "Bus %04x:%02x not present in PCI namespace\n",
493 			    root->id.segment, root->id.bus);
494 		result = -ENODEV;
495 		goto end;
496 	}
497 
498 	/*
499 	 * Attach ACPI-PCI Context
500 	 * -----------------------
501 	 * Thus binding the ACPI and PCI devices.
502 	 */
503 	result = acpi_pci_bind_root(device, &root->id, root->bus);
504 	if (result)
505 		goto end;
506 
507 	/*
508 	 * PCI Routing Table
509 	 * -----------------
510 	 * Evaluate and parse _PRT, if exists.
511 	 */
512 	status = acpi_get_handle(device->handle, METHOD_NAME__PRT, &handle);
513 	if (ACPI_SUCCESS(status))
514 		result = acpi_pci_irq_add_prt(device->handle, root->id.segment,
515 					      root->id.bus);
516 
517 	/*
518 	 * Scan and bind all _ADR-Based Devices
519 	 */
520 	list_for_each_entry(child, &device->children, node)
521 		acpi_pci_bridge_scan(child);
522 
523 	/* Indicate support for various _OSC capabilities. */
524 	if (pci_ext_cfg_avail(root->bus->self))
525 		flags |= OSC_EXT_PCI_CONFIG_SUPPORT;
526 	if (pcie_aspm_enabled())
527 		flags |= OSC_ACTIVE_STATE_PWR_SUPPORT |
528 			OSC_CLOCK_PWR_CAPABILITY_SUPPORT;
529 	if (pci_msi_enabled())
530 		flags |= OSC_MSI_SUPPORT;
531 	if (flags != base_flags)
532 		acpi_pci_osc_support(root, flags);
533 
534       end:
535 	if (result) {
536 		if (!list_empty(&root->node))
537 			list_del(&root->node);
538 		kfree(root);
539 	}
540 
541 	return result;
542 }
543 
544 static int acpi_pci_root_start(struct acpi_device *device)
545 {
546 	struct acpi_pci_root *root;
547 
548 
549 	list_for_each_entry(root, &acpi_pci_roots, node) {
550 		if (root->device == device) {
551 			pci_bus_add_devices(root->bus);
552 			return 0;
553 		}
554 	}
555 	return -ENODEV;
556 }
557 
558 static int acpi_pci_root_remove(struct acpi_device *device, int type)
559 {
560 	struct acpi_pci_root *root = NULL;
561 
562 
563 	if (!device || !acpi_driver_data(device))
564 		return -EINVAL;
565 
566 	root = acpi_driver_data(device);
567 
568 	kfree(root);
569 
570 	return 0;
571 }
572 
573 static int __init acpi_pci_root_init(void)
574 {
575 	if (acpi_pci_disabled)
576 		return 0;
577 
578 	if (acpi_bus_register_driver(&acpi_pci_root_driver) < 0)
579 		return -ENODEV;
580 
581 	return 0;
582 }
583 
584 subsys_initcall(acpi_pci_root_init);
585