xref: /linux/drivers/pnp/pnpbios/core.c (revision 831441862956fffa17b9801db37e6ea1650b0f69)
1 /*
2  * pnpbios -- PnP BIOS driver
3  *
4  * This driver provides access to Plug-'n'-Play services provided by
5  * the PnP BIOS firmware, described in the following documents:
6  *   Plug and Play BIOS Specification, Version 1.0A, 5 May 1994
7  *   Plug and Play BIOS Clarification Paper, 6 October 1994
8  *     Compaq Computer Corporation, Phoenix Technologies Ltd., Intel Corp.
9  *
10  * Originally (C) 1998 Christian Schmidt <schmidt@digadd.de>
11  * Modifications (C) 1998 Tom Lees <tom@lpsg.demon.co.uk>
12  * Minor reorganizations by David Hinds <dahinds@users.sourceforge.net>
13  * Further modifications (C) 2001, 2002 by:
14  *   Alan Cox <alan@redhat.com>
15  *   Thomas Hood
16  *   Brian Gerst <bgerst@didntduck.org>
17  *
18  * Ported to the PnP Layer and several additional improvements (C) 2002
19  * by Adam Belay <ambx1@neo.rr.com>
20  *
21  * This program is free software; you can redistribute it and/or modify it
22  * under the terms of the GNU General Public License as published by the
23  * Free Software Foundation; either version 2, or (at your option) any
24  * later version.
25  *
26  * This program is distributed in the hope that it will be useful, but
27  * WITHOUT ANY WARRANTY; without even the implied warranty of
28  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
29  * General Public License for more details.
30  *
31  * You should have received a copy of the GNU General Public License
32  * along with this program; if not, write to the Free Software
33  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
34  */
35 
36 /* Change Log
37  *
38  * Adam Belay - <ambx1@neo.rr.com> - March 16, 2003
39  * rev 1.01	Only call pnp_bios_dev_node_info once
40  *		Added pnpbios_print_status
41  *		Added several new error messages and info messages
42  *		Added pnpbios_interface_attach_device
43  *		integrated core and proc init system
44  *		Introduced PNPMODE flags
45  *		Removed some useless includes
46  */
47 
48 #include <linux/types.h>
49 #include <linux/module.h>
50 #include <linux/init.h>
51 #include <linux/linkage.h>
52 #include <linux/kernel.h>
53 #include <linux/pnpbios.h>
54 #include <linux/device.h>
55 #include <linux/pnp.h>
56 #include <linux/mm.h>
57 #include <linux/smp.h>
58 #include <linux/slab.h>
59 #include <linux/completion.h>
60 #include <linux/spinlock.h>
61 #include <linux/dmi.h>
62 #include <linux/delay.h>
63 #include <linux/acpi.h>
64 #include <linux/freezer.h>
65 #include <linux/kthread.h>
66 
67 #include <asm/page.h>
68 #include <asm/desc.h>
69 #include <asm/system.h>
70 #include <asm/byteorder.h>
71 
72 #include "pnpbios.h"
73 
74 
75 /*
76  *
77  * PnP BIOS INTERFACE
78  *
79  */
80 
81 static union pnp_bios_install_struct * pnp_bios_install = NULL;
82 
83 int pnp_bios_present(void)
84 {
85 	return (pnp_bios_install != NULL);
86 }
87 
88 struct pnp_dev_node_info node_info;
89 
90 /*
91  *
92  * DOCKING FUNCTIONS
93  *
94  */
95 
96 #ifdef CONFIG_HOTPLUG
97 
98 static int unloading = 0;
99 static struct completion unload_sem;
100 
101 /*
102  * (Much of this belongs in a shared routine somewhere)
103  */
104 
105 static int pnp_dock_event(int dock, struct pnp_docking_station_info *info)
106 {
107 	char *argv [3], **envp, *buf, *scratch;
108 	int i = 0, value;
109 
110 	if (!current->fs->root) {
111 		return -EAGAIN;
112 	}
113 	if (!(envp = kcalloc(20, sizeof (char *), GFP_KERNEL))) {
114 		return -ENOMEM;
115 	}
116 	if (!(buf = kzalloc(256, GFP_KERNEL))) {
117 		kfree (envp);
118 		return -ENOMEM;
119 	}
120 
121 	/* FIXME: if there are actual users of this, it should be integrated into
122 	 * the driver core and use the usual infrastructure like sysfs and uevents */
123 	argv [0] = "/sbin/pnpbios";
124 	argv [1] = "dock";
125 	argv [2] = NULL;
126 
127 	/* minimal command environment */
128 	envp [i++] = "HOME=/";
129 	envp [i++] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin";
130 
131 #ifdef	DEBUG
132 	/* hint that policy agent should enter no-stdout debug mode */
133 	envp [i++] = "DEBUG=kernel";
134 #endif
135 	/* extensible set of named bus-specific parameters,
136 	 * supporting multiple driver selection algorithms.
137 	 */
138 	scratch = buf;
139 
140 	/* action:  add, remove */
141 	envp [i++] = scratch;
142 	scratch += sprintf (scratch, "ACTION=%s", dock?"add":"remove") + 1;
143 
144 	/* Report the ident for the dock */
145 	envp [i++] = scratch;
146 	scratch += sprintf (scratch, "DOCK=%x/%x/%x",
147 		info->location_id, info->serial, info->capabilities);
148 	envp[i] = NULL;
149 
150 	value = call_usermodehelper (argv [0], argv, envp, 0);
151 	kfree (buf);
152 	kfree (envp);
153 	return 0;
154 }
155 
156 /*
157  * Poll the PnP docking at regular intervals
158  */
159 static int pnp_dock_thread(void * unused)
160 {
161 	static struct pnp_docking_station_info now;
162 	int docked = -1, d = 0;
163 	set_freezable();
164 	while (!unloading)
165 	{
166 		int status;
167 
168 		/*
169 		 * Poll every 2 seconds
170 		 */
171 		msleep_interruptible(2000);
172 
173 		if (try_to_freeze())
174 			continue;
175 
176 		status = pnp_bios_dock_station_info(&now);
177 
178 		switch(status)
179 		{
180 			/*
181 			 * No dock to manage
182 			 */
183 			case PNP_FUNCTION_NOT_SUPPORTED:
184 				complete_and_exit(&unload_sem, 0);
185 			case PNP_SYSTEM_NOT_DOCKED:
186 				d = 0;
187 				break;
188 			case PNP_SUCCESS:
189 				d = 1;
190 				break;
191 			default:
192 				pnpbios_print_status( "pnp_dock_thread", status );
193 				continue;
194 		}
195 		if(d != docked)
196 		{
197 			if(pnp_dock_event(d, &now)==0)
198 			{
199 				docked = d;
200 #if 0
201 				printk(KERN_INFO "PnPBIOS: Docking station %stached\n", docked?"at":"de");
202 #endif
203 			}
204 		}
205 	}
206 	complete_and_exit(&unload_sem, 0);
207 }
208 
209 #endif   /* CONFIG_HOTPLUG */
210 
211 static int pnpbios_get_resources(struct pnp_dev * dev, struct pnp_resource_table * res)
212 {
213 	u8 nodenum = dev->number;
214 	struct pnp_bios_node * node;
215 
216 	/* just in case */
217 	if(!pnpbios_is_dynamic(dev))
218 		return -EPERM;
219 
220 	node = kzalloc(node_info.max_node_size, GFP_KERNEL);
221 	if (!node)
222 		return -1;
223 	if (pnp_bios_get_dev_node(&nodenum, (char )PNPMODE_DYNAMIC, node)) {
224 		kfree(node);
225 		return -ENODEV;
226 	}
227 	pnpbios_read_resources_from_node(res, node);
228 	dev->active = pnp_is_active(dev);
229 	kfree(node);
230 	return 0;
231 }
232 
233 static int pnpbios_set_resources(struct pnp_dev * dev, struct pnp_resource_table * res)
234 {
235 	u8 nodenum = dev->number;
236 	struct pnp_bios_node * node;
237 	int ret;
238 
239 	/* just in case */
240 	if (!pnpbios_is_dynamic(dev))
241 		return -EPERM;
242 
243 	node = kzalloc(node_info.max_node_size, GFP_KERNEL);
244 	if (!node)
245 		return -1;
246 	if (pnp_bios_get_dev_node(&nodenum, (char )PNPMODE_DYNAMIC, node)) {
247 		kfree(node);
248 		return -ENODEV;
249 	}
250 	if(pnpbios_write_resources_to_node(res, node)<0) {
251 		kfree(node);
252 		return -1;
253 	}
254 	ret = pnp_bios_set_dev_node(node->handle, (char)PNPMODE_DYNAMIC, node);
255 	kfree(node);
256 	if (ret > 0)
257 		ret = -1;
258 	return ret;
259 }
260 
261 static void pnpbios_zero_data_stream(struct pnp_bios_node * node)
262 {
263 	unsigned char * p = (char *)node->data;
264 	unsigned char * end = (char *)(node->data + node->size);
265 	unsigned int len;
266 	int i;
267 	while ((char *)p < (char *)end) {
268 		if(p[0] & 0x80) { /* large tag */
269 			len = (p[2] << 8) | p[1];
270 			p += 3;
271 		} else {
272 			if (((p[0]>>3) & 0x0f) == 0x0f)
273 				return;
274 			len = p[0] & 0x07;
275 			p += 1;
276 		}
277 		for (i = 0; i < len; i++)
278 			p[i] = 0;
279 		p += len;
280 	}
281 	printk(KERN_ERR "PnPBIOS: Resource structure did not contain an end tag.\n");
282 }
283 
284 static int pnpbios_disable_resources(struct pnp_dev *dev)
285 {
286 	struct pnp_bios_node * node;
287 	u8 nodenum = dev->number;
288 	int ret;
289 
290 	/* just in case */
291 	if(dev->flags & PNPBIOS_NO_DISABLE || !pnpbios_is_dynamic(dev))
292 		return -EPERM;
293 
294 	node = kzalloc(node_info.max_node_size, GFP_KERNEL);
295 	if (!node)
296 		return -ENOMEM;
297 
298 	if (pnp_bios_get_dev_node(&nodenum, (char )PNPMODE_DYNAMIC, node)) {
299 		kfree(node);
300 		return -ENODEV;
301 	}
302 	pnpbios_zero_data_stream(node);
303 
304 	ret = pnp_bios_set_dev_node(dev->number, (char)PNPMODE_DYNAMIC, node);
305 	kfree(node);
306 	if (ret > 0)
307 		ret = -1;
308 	return ret;
309 }
310 
311 /* PnP Layer support */
312 
313 struct pnp_protocol pnpbios_protocol = {
314 	.name	= "Plug and Play BIOS",
315 	.get	= pnpbios_get_resources,
316 	.set	= pnpbios_set_resources,
317 	.disable = pnpbios_disable_resources,
318 };
319 
320 static int insert_device(struct pnp_dev *dev, struct pnp_bios_node * node)
321 {
322 	struct list_head * pos;
323 	struct pnp_dev * pnp_dev;
324 	struct pnp_id *dev_id;
325 	char id[8];
326 
327 	/* check if the device is already added */
328 	dev->number = node->handle;
329 	list_for_each (pos, &pnpbios_protocol.devices){
330 		pnp_dev = list_entry(pos, struct pnp_dev, protocol_list);
331 		if (dev->number == pnp_dev->number)
332 			return -1;
333 	}
334 
335 	/* set the initial values for the PnP device */
336 	dev_id = kzalloc(sizeof(struct pnp_id), GFP_KERNEL);
337 	if (!dev_id)
338 		return -1;
339 	pnpid32_to_pnpid(node->eisa_id,id);
340 	memcpy(dev_id->id,id,7);
341 	pnp_add_id(dev_id, dev);
342 	pnpbios_parse_data_stream(dev, node);
343 	dev->active = pnp_is_active(dev);
344 	dev->flags = node->flags;
345 	if (!(dev->flags & PNPBIOS_NO_CONFIG))
346 		dev->capabilities |= PNP_CONFIGURABLE;
347 	if (!(dev->flags & PNPBIOS_NO_DISABLE) && pnpbios_is_dynamic(dev))
348 		dev->capabilities |= PNP_DISABLE;
349 	dev->capabilities |= PNP_READ;
350 	if (pnpbios_is_dynamic(dev))
351 		dev->capabilities |= PNP_WRITE;
352 	if (dev->flags & PNPBIOS_REMOVABLE)
353 		dev->capabilities |= PNP_REMOVABLE;
354 	dev->protocol = &pnpbios_protocol;
355 
356 	/* clear out the damaged flags */
357 	if (!dev->active)
358 		pnp_init_resource_table(&dev->res);
359 
360 	pnp_add_device(dev);
361 	pnpbios_interface_attach_device(node);
362 
363 	return 0;
364 }
365 
366 static void __init build_devlist(void)
367 {
368 	u8 nodenum;
369 	unsigned int nodes_got = 0;
370 	unsigned int devs = 0;
371 	struct pnp_bios_node *node;
372 	struct pnp_dev *dev;
373 
374 	node = kzalloc(node_info.max_node_size, GFP_KERNEL);
375 	if (!node)
376 		return;
377 
378 	for(nodenum=0; nodenum<0xff; ) {
379 		u8 thisnodenum = nodenum;
380 		/* eventually we will want to use PNPMODE_STATIC here but for now
381 		 * dynamic will help us catch buggy bioses to add to the blacklist.
382 		 */
383 		if (!pnpbios_dont_use_current_config) {
384 			if (pnp_bios_get_dev_node(&nodenum, (char )PNPMODE_DYNAMIC, node))
385 				break;
386 		} else {
387 			if (pnp_bios_get_dev_node(&nodenum, (char )PNPMODE_STATIC, node))
388 				break;
389 		}
390 		nodes_got++;
391 		dev =  kzalloc(sizeof (struct pnp_dev), GFP_KERNEL);
392 		if (!dev)
393 			break;
394 		if(insert_device(dev,node)<0)
395 			kfree(dev);
396 		else
397 			devs++;
398 		if (nodenum <= thisnodenum) {
399 			printk(KERN_ERR "PnPBIOS: build_devlist: Node number 0x%x is out of sequence following node 0x%x. Aborting.\n", (unsigned int)nodenum, (unsigned int)thisnodenum);
400 			break;
401 		}
402 	}
403 	kfree(node);
404 
405 	printk(KERN_INFO "PnPBIOS: %i node%s reported by PnP BIOS; %i recorded by driver\n",
406 		nodes_got, nodes_got != 1 ? "s" : "", devs);
407 }
408 
409 /*
410  *
411  * INIT AND EXIT
412  *
413  */
414 
415 static int pnpbios_disabled; /* = 0 */
416 int pnpbios_dont_use_current_config; /* = 0 */
417 
418 #ifndef MODULE
419 static int __init pnpbios_setup(char *str)
420 {
421 	int invert;
422 
423 	while ((str != NULL) && (*str != '\0')) {
424 		if (strncmp(str, "off", 3) == 0)
425 			pnpbios_disabled=1;
426 		if (strncmp(str, "on", 2) == 0)
427 			pnpbios_disabled=0;
428 		invert = (strncmp(str, "no-", 3) == 0);
429 		if (invert)
430 			str += 3;
431 		if (strncmp(str, "curr", 4) == 0)
432 			pnpbios_dont_use_current_config = invert;
433 		str = strchr(str, ',');
434 		if (str != NULL)
435 			str += strspn(str, ", \t");
436 	}
437 
438 	return 1;
439 }
440 
441 __setup("pnpbios=", pnpbios_setup);
442 #endif
443 
444 /* PnP BIOS signature: "$PnP" */
445 #define PNP_SIGNATURE   (('$' << 0) + ('P' << 8) + ('n' << 16) + ('P' << 24))
446 
447 static int __init pnpbios_probe_system(void)
448 {
449 	union pnp_bios_install_struct *check;
450 	u8 sum;
451 	int length, i;
452 
453 	printk(KERN_INFO "PnPBIOS: Scanning system for PnP BIOS support...\n");
454 
455 	/*
456  	 * Search the defined area (0xf0000-0xffff0) for a valid PnP BIOS
457 	 * structure and, if one is found, sets up the selectors and
458 	 * entry points
459 	 */
460 	for (check = (union pnp_bios_install_struct *) __va(0xf0000);
461 	     check < (union pnp_bios_install_struct *) __va(0xffff0);
462 	     check = (void *)check + 16) {
463 		if (check->fields.signature != PNP_SIGNATURE)
464 			continue;
465 		printk(KERN_INFO "PnPBIOS: Found PnP BIOS installation structure at 0x%p\n", check);
466 		length = check->fields.length;
467 		if (!length) {
468 			printk(KERN_ERR "PnPBIOS: installation structure is invalid, skipping\n");
469 			continue;
470 		}
471 		for (sum = 0, i = 0; i < length; i++)
472 			sum += check->chars[i];
473 		if (sum) {
474 			printk(KERN_ERR "PnPBIOS: installation structure is corrupted, skipping\n");
475 			continue;
476 		}
477 		if (check->fields.version < 0x10) {
478 			printk(KERN_WARNING "PnPBIOS: PnP BIOS version %d.%d is not supported\n",
479 			       check->fields.version >> 4,
480 			       check->fields.version & 15);
481 			continue;
482 		}
483 		printk(KERN_INFO "PnPBIOS: PnP BIOS version %d.%d, entry 0x%x:0x%x, dseg 0x%x\n",
484                        check->fields.version >> 4, check->fields.version & 15,
485 		       check->fields.pm16cseg, check->fields.pm16offset,
486 		       check->fields.pm16dseg);
487 		pnp_bios_install = check;
488 		return 1;
489 	}
490 
491 	printk(KERN_INFO "PnPBIOS: PnP BIOS support was not detected.\n");
492 	return 0;
493 }
494 
495 static int __init exploding_pnp_bios(struct dmi_system_id *d)
496 {
497 	printk(KERN_WARNING "%s detected. Disabling PnPBIOS\n", d->ident);
498 	return 0;
499 }
500 
501 static struct dmi_system_id pnpbios_dmi_table[] __initdata = {
502 	{	/* PnPBIOS GPF on boot */
503 		.callback = exploding_pnp_bios,
504 		.ident = "Higraded P14H",
505 		.matches = {
506 			DMI_MATCH(DMI_BIOS_VENDOR, "American Megatrends Inc."),
507 			DMI_MATCH(DMI_BIOS_VERSION, "07.00T"),
508 			DMI_MATCH(DMI_SYS_VENDOR, "Higraded"),
509 			DMI_MATCH(DMI_PRODUCT_NAME, "P14H"),
510 		},
511 	},
512 	{	/* PnPBIOS GPF on boot */
513 		.callback = exploding_pnp_bios,
514 		.ident = "ASUS P4P800",
515 		.matches = {
516 			DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer Inc."),
517 			DMI_MATCH(DMI_BOARD_NAME, "P4P800"),
518 		},
519 	},
520 	{ }
521 };
522 
523 static int __init pnpbios_init(void)
524 {
525 	int ret;
526 
527 #if defined(CONFIG_PPC_MERGE)
528 	if (check_legacy_ioport(PNPBIOS_BASE))
529 		return -ENODEV;
530 #endif
531 	if (pnpbios_disabled || dmi_check_system(pnpbios_dmi_table) ||
532 	    paravirt_enabled()) {
533 		printk(KERN_INFO "PnPBIOS: Disabled\n");
534 		return -ENODEV;
535 	}
536 
537 #ifdef CONFIG_PNPACPI
538 	if (!acpi_disabled && !pnpacpi_disabled) {
539 		pnpbios_disabled = 1;
540 		printk(KERN_INFO "PnPBIOS: Disabled by ACPI PNP\n");
541 		return -ENODEV;
542 	}
543 #endif /* CONFIG_ACPI */
544 
545 	/* scan the system for pnpbios support */
546 	if (!pnpbios_probe_system())
547 		return -ENODEV;
548 
549 	/* make preparations for bios calls */
550 	pnpbios_calls_init(pnp_bios_install);
551 
552 	/* read the node info */
553 	ret = pnp_bios_dev_node_info(&node_info);
554 	if (ret) {
555 		printk(KERN_ERR "PnPBIOS: Unable to get node info.  Aborting.\n");
556 		return ret;
557 	}
558 
559 	/* register with the pnp layer */
560 	ret = pnp_register_protocol(&pnpbios_protocol);
561 	if (ret) {
562 		printk(KERN_ERR "PnPBIOS: Unable to register driver.  Aborting.\n");
563 		return ret;
564 	}
565 
566 	/* start the proc interface */
567 	ret = pnpbios_proc_init();
568 	if (ret)
569 		printk(KERN_ERR "PnPBIOS: Failed to create proc interface.\n");
570 
571 	/* scan for pnpbios devices */
572 	build_devlist();
573 
574 	pnp_platform_devices = 1;
575 	return 0;
576 }
577 
578 subsys_initcall(pnpbios_init);
579 
580 static int __init pnpbios_thread_init(void)
581 {
582 	struct task_struct *task;
583 #if defined(CONFIG_PPC_MERGE)
584 	if (check_legacy_ioport(PNPBIOS_BASE))
585 		return 0;
586 #endif
587 	if (pnpbios_disabled)
588 		return 0;
589 #ifdef CONFIG_HOTPLUG
590 	init_completion(&unload_sem);
591 	task = kthread_run(pnp_dock_thread, NULL, "kpnpbiosd");
592 	if (!IS_ERR(task))
593 		unloading = 0;
594 #endif
595 	return 0;
596 }
597 
598 #ifndef MODULE
599 
600 /* init/main.c calls pnpbios_init early */
601 
602 /* Start the kernel thread later: */
603 module_init(pnpbios_thread_init);
604 
605 #else
606 
607 /*
608  * N.B.: Building pnpbios as a module hasn't been fully implemented
609  */
610 
611 MODULE_LICENSE("GPL");
612 
613 static int __init pnpbios_init_all(void)
614 {
615 	int r;
616 
617 	r = pnpbios_init();
618 	if (r)
619 		return r;
620 	r = pnpbios_thread_init();
621 	if (r)
622 		return r;
623 	return 0;
624 }
625 
626 static void __exit pnpbios_exit(void)
627 {
628 #ifdef CONFIG_HOTPLUG
629 	unloading = 1;
630 	wait_for_completion(&unload_sem);
631 #endif
632 	pnpbios_proc_exit();
633 	/* We ought to free resources here */
634 	return;
635 }
636 
637 module_init(pnpbios_init_all);
638 module_exit(pnpbios_exit);
639 
640 #endif
641 
642 EXPORT_SYMBOL(pnpbios_protocol);
643