xref: /linux/drivers/pnp/pnpbios/core.c (revision c537b994505099b7197e7d3125b942ecbcc51eb6)
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 
66 #include <asm/page.h>
67 #include <asm/desc.h>
68 #include <asm/system.h>
69 #include <asm/byteorder.h>
70 
71 #include "pnpbios.h"
72 
73 
74 /*
75  *
76  * PnP BIOS INTERFACE
77  *
78  */
79 
80 static union pnp_bios_install_struct * pnp_bios_install = NULL;
81 
82 int pnp_bios_present(void)
83 {
84 	return (pnp_bios_install != NULL);
85 }
86 
87 struct pnp_dev_node_info node_info;
88 
89 /*
90  *
91  * DOCKING FUNCTIONS
92  *
93  */
94 
95 #ifdef CONFIG_HOTPLUG
96 
97 static int unloading = 0;
98 static struct completion unload_sem;
99 
100 /*
101  * (Much of this belongs in a shared routine somewhere)
102  */
103 
104 static int pnp_dock_event(int dock, struct pnp_docking_station_info *info)
105 {
106 	char *argv [3], **envp, *buf, *scratch;
107 	int i = 0, value;
108 
109 	if (!current->fs->root) {
110 		return -EAGAIN;
111 	}
112 	if (!(envp = kcalloc(20, sizeof (char *), GFP_KERNEL))) {
113 		return -ENOMEM;
114 	}
115 	if (!(buf = kzalloc(256, GFP_KERNEL))) {
116 		kfree (envp);
117 		return -ENOMEM;
118 	}
119 
120 	/* FIXME: if there are actual users of this, it should be integrated into
121 	 * the driver core and use the usual infrastructure like sysfs and uevents */
122 	argv [0] = "/sbin/pnpbios";
123 	argv [1] = "dock";
124 	argv [2] = NULL;
125 
126 	/* minimal command environment */
127 	envp [i++] = "HOME=/";
128 	envp [i++] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin";
129 
130 #ifdef	DEBUG
131 	/* hint that policy agent should enter no-stdout debug mode */
132 	envp [i++] = "DEBUG=kernel";
133 #endif
134 	/* extensible set of named bus-specific parameters,
135 	 * supporting multiple driver selection algorithms.
136 	 */
137 	scratch = buf;
138 
139 	/* action:  add, remove */
140 	envp [i++] = scratch;
141 	scratch += sprintf (scratch, "ACTION=%s", dock?"add":"remove") + 1;
142 
143 	/* Report the ident for the dock */
144 	envp [i++] = scratch;
145 	scratch += sprintf (scratch, "DOCK=%x/%x/%x",
146 		info->location_id, info->serial, info->capabilities);
147 	envp[i] = NULL;
148 
149 	value = call_usermodehelper (argv [0], argv, envp, 0);
150 	kfree (buf);
151 	kfree (envp);
152 	return 0;
153 }
154 
155 /*
156  * Poll the PnP docking at regular intervals
157  */
158 static int pnp_dock_thread(void * unused)
159 {
160 	static struct pnp_docking_station_info now;
161 	int docked = -1, d = 0;
162 	daemonize("kpnpbiosd");
163 	allow_signal(SIGKILL);
164 	while(!unloading && !signal_pending(current))
165 	{
166 		int status;
167 
168 		/*
169 		 * Poll every 2 seconds
170 		 */
171 		msleep_interruptible(2000);
172 
173 		if(signal_pending(current)) {
174 			if (try_to_freeze())
175 				continue;
176 			break;
177 		}
178 
179 		status = pnp_bios_dock_station_info(&now);
180 
181 		switch(status)
182 		{
183 			/*
184 			 * No dock to manage
185 			 */
186 			case PNP_FUNCTION_NOT_SUPPORTED:
187 				complete_and_exit(&unload_sem, 0);
188 			case PNP_SYSTEM_NOT_DOCKED:
189 				d = 0;
190 				break;
191 			case PNP_SUCCESS:
192 				d = 1;
193 				break;
194 			default:
195 				pnpbios_print_status( "pnp_dock_thread", status );
196 				continue;
197 		}
198 		if(d != docked)
199 		{
200 			if(pnp_dock_event(d, &now)==0)
201 			{
202 				docked = d;
203 #if 0
204 				printk(KERN_INFO "PnPBIOS: Docking station %stached\n", docked?"at":"de");
205 #endif
206 			}
207 		}
208 	}
209 	complete_and_exit(&unload_sem, 0);
210 }
211 
212 #endif   /* CONFIG_HOTPLUG */
213 
214 static int pnpbios_get_resources(struct pnp_dev * dev, struct pnp_resource_table * res)
215 {
216 	u8 nodenum = dev->number;
217 	struct pnp_bios_node * node;
218 
219 	/* just in case */
220 	if(!pnpbios_is_dynamic(dev))
221 		return -EPERM;
222 
223 	node = kzalloc(node_info.max_node_size, GFP_KERNEL);
224 	if (!node)
225 		return -1;
226 	if (pnp_bios_get_dev_node(&nodenum, (char )PNPMODE_DYNAMIC, node)) {
227 		kfree(node);
228 		return -ENODEV;
229 	}
230 	pnpbios_read_resources_from_node(res, node);
231 	dev->active = pnp_is_active(dev);
232 	kfree(node);
233 	return 0;
234 }
235 
236 static int pnpbios_set_resources(struct pnp_dev * dev, struct pnp_resource_table * res)
237 {
238 	u8 nodenum = dev->number;
239 	struct pnp_bios_node * node;
240 	int ret;
241 
242 	/* just in case */
243 	if (!pnpbios_is_dynamic(dev))
244 		return -EPERM;
245 
246 	node = kzalloc(node_info.max_node_size, GFP_KERNEL);
247 	if (!node)
248 		return -1;
249 	if (pnp_bios_get_dev_node(&nodenum, (char )PNPMODE_DYNAMIC, node)) {
250 		kfree(node);
251 		return -ENODEV;
252 	}
253 	if(pnpbios_write_resources_to_node(res, node)<0) {
254 		kfree(node);
255 		return -1;
256 	}
257 	ret = pnp_bios_set_dev_node(node->handle, (char)PNPMODE_DYNAMIC, node);
258 	kfree(node);
259 	if (ret > 0)
260 		ret = -1;
261 	return ret;
262 }
263 
264 static void pnpbios_zero_data_stream(struct pnp_bios_node * node)
265 {
266 	unsigned char * p = (char *)node->data;
267 	unsigned char * end = (char *)(node->data + node->size);
268 	unsigned int len;
269 	int i;
270 	while ((char *)p < (char *)end) {
271 		if(p[0] & 0x80) { /* large tag */
272 			len = (p[2] << 8) | p[1];
273 			p += 3;
274 		} else {
275 			if (((p[0]>>3) & 0x0f) == 0x0f)
276 				return;
277 			len = p[0] & 0x07;
278 			p += 1;
279 		}
280 		for (i = 0; i < len; i++)
281 			p[i] = 0;
282 		p += len;
283 	}
284 	printk(KERN_ERR "PnPBIOS: Resource structure did not contain an end tag.\n");
285 }
286 
287 static int pnpbios_disable_resources(struct pnp_dev *dev)
288 {
289 	struct pnp_bios_node * node;
290 	u8 nodenum = dev->number;
291 	int ret;
292 
293 	/* just in case */
294 	if(dev->flags & PNPBIOS_NO_DISABLE || !pnpbios_is_dynamic(dev))
295 		return -EPERM;
296 
297 	node = kzalloc(node_info.max_node_size, GFP_KERNEL);
298 	if (!node)
299 		return -ENOMEM;
300 
301 	if (pnp_bios_get_dev_node(&nodenum, (char )PNPMODE_DYNAMIC, node)) {
302 		kfree(node);
303 		return -ENODEV;
304 	}
305 	pnpbios_zero_data_stream(node);
306 
307 	ret = pnp_bios_set_dev_node(dev->number, (char)PNPMODE_DYNAMIC, node);
308 	kfree(node);
309 	if (ret > 0)
310 		ret = -1;
311 	return ret;
312 }
313 
314 /* PnP Layer support */
315 
316 struct pnp_protocol pnpbios_protocol = {
317 	.name	= "Plug and Play BIOS",
318 	.get	= pnpbios_get_resources,
319 	.set	= pnpbios_set_resources,
320 	.disable = pnpbios_disable_resources,
321 };
322 
323 static int insert_device(struct pnp_dev *dev, struct pnp_bios_node * node)
324 {
325 	struct list_head * pos;
326 	struct pnp_dev * pnp_dev;
327 	struct pnp_id *dev_id;
328 	char id[8];
329 
330 	/* check if the device is already added */
331 	dev->number = node->handle;
332 	list_for_each (pos, &pnpbios_protocol.devices){
333 		pnp_dev = list_entry(pos, struct pnp_dev, protocol_list);
334 		if (dev->number == pnp_dev->number)
335 			return -1;
336 	}
337 
338 	/* set the initial values for the PnP device */
339 	dev_id = kzalloc(sizeof(struct pnp_id), GFP_KERNEL);
340 	if (!dev_id)
341 		return -1;
342 	pnpid32_to_pnpid(node->eisa_id,id);
343 	memcpy(dev_id->id,id,7);
344 	pnp_add_id(dev_id, dev);
345 	pnpbios_parse_data_stream(dev, node);
346 	dev->active = pnp_is_active(dev);
347 	dev->flags = node->flags;
348 	if (!(dev->flags & PNPBIOS_NO_CONFIG))
349 		dev->capabilities |= PNP_CONFIGURABLE;
350 	if (!(dev->flags & PNPBIOS_NO_DISABLE) && pnpbios_is_dynamic(dev))
351 		dev->capabilities |= PNP_DISABLE;
352 	dev->capabilities |= PNP_READ;
353 	if (pnpbios_is_dynamic(dev))
354 		dev->capabilities |= PNP_WRITE;
355 	if (dev->flags & PNPBIOS_REMOVABLE)
356 		dev->capabilities |= PNP_REMOVABLE;
357 	dev->protocol = &pnpbios_protocol;
358 
359 	/* clear out the damaged flags */
360 	if (!dev->active)
361 		pnp_init_resource_table(&dev->res);
362 
363 	pnp_add_device(dev);
364 	pnpbios_interface_attach_device(node);
365 
366 	return 0;
367 }
368 
369 static void __init build_devlist(void)
370 {
371 	u8 nodenum;
372 	unsigned int nodes_got = 0;
373 	unsigned int devs = 0;
374 	struct pnp_bios_node *node;
375 	struct pnp_dev *dev;
376 
377 	node = kzalloc(node_info.max_node_size, GFP_KERNEL);
378 	if (!node)
379 		return;
380 
381 	for(nodenum=0; nodenum<0xff; ) {
382 		u8 thisnodenum = nodenum;
383 		/* eventually we will want to use PNPMODE_STATIC here but for now
384 		 * dynamic will help us catch buggy bioses to add to the blacklist.
385 		 */
386 		if (!pnpbios_dont_use_current_config) {
387 			if (pnp_bios_get_dev_node(&nodenum, (char )PNPMODE_DYNAMIC, node))
388 				break;
389 		} else {
390 			if (pnp_bios_get_dev_node(&nodenum, (char )PNPMODE_STATIC, node))
391 				break;
392 		}
393 		nodes_got++;
394 		dev =  kzalloc(sizeof (struct pnp_dev), GFP_KERNEL);
395 		if (!dev)
396 			break;
397 		if(insert_device(dev,node)<0)
398 			kfree(dev);
399 		else
400 			devs++;
401 		if (nodenum <= thisnodenum) {
402 			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);
403 			break;
404 		}
405 	}
406 	kfree(node);
407 
408 	printk(KERN_INFO "PnPBIOS: %i node%s reported by PnP BIOS; %i recorded by driver\n",
409 		nodes_got, nodes_got != 1 ? "s" : "", devs);
410 }
411 
412 /*
413  *
414  * INIT AND EXIT
415  *
416  */
417 
418 static int pnpbios_disabled; /* = 0 */
419 int pnpbios_dont_use_current_config; /* = 0 */
420 
421 #ifndef MODULE
422 static int __init pnpbios_setup(char *str)
423 {
424 	int invert;
425 
426 	while ((str != NULL) && (*str != '\0')) {
427 		if (strncmp(str, "off", 3) == 0)
428 			pnpbios_disabled=1;
429 		if (strncmp(str, "on", 2) == 0)
430 			pnpbios_disabled=0;
431 		invert = (strncmp(str, "no-", 3) == 0);
432 		if (invert)
433 			str += 3;
434 		if (strncmp(str, "curr", 4) == 0)
435 			pnpbios_dont_use_current_config = invert;
436 		str = strchr(str, ',');
437 		if (str != NULL)
438 			str += strspn(str, ", \t");
439 	}
440 
441 	return 1;
442 }
443 
444 __setup("pnpbios=", pnpbios_setup);
445 #endif
446 
447 /* PnP BIOS signature: "$PnP" */
448 #define PNP_SIGNATURE   (('$' << 0) + ('P' << 8) + ('n' << 16) + ('P' << 24))
449 
450 static int __init pnpbios_probe_system(void)
451 {
452 	union pnp_bios_install_struct *check;
453 	u8 sum;
454 	int length, i;
455 
456 	printk(KERN_INFO "PnPBIOS: Scanning system for PnP BIOS support...\n");
457 
458 	/*
459  	 * Search the defined area (0xf0000-0xffff0) for a valid PnP BIOS
460 	 * structure and, if one is found, sets up the selectors and
461 	 * entry points
462 	 */
463 	for (check = (union pnp_bios_install_struct *) __va(0xf0000);
464 	     check < (union pnp_bios_install_struct *) __va(0xffff0);
465 	     check = (void *)check + 16) {
466 		if (check->fields.signature != PNP_SIGNATURE)
467 			continue;
468 		printk(KERN_INFO "PnPBIOS: Found PnP BIOS installation structure at 0x%p\n", check);
469 		length = check->fields.length;
470 		if (!length) {
471 			printk(KERN_ERR "PnPBIOS: installation structure is invalid, skipping\n");
472 			continue;
473 		}
474 		for (sum = 0, i = 0; i < length; i++)
475 			sum += check->chars[i];
476 		if (sum) {
477 			printk(KERN_ERR "PnPBIOS: installation structure is corrupted, skipping\n");
478 			continue;
479 		}
480 		if (check->fields.version < 0x10) {
481 			printk(KERN_WARNING "PnPBIOS: PnP BIOS version %d.%d is not supported\n",
482 			       check->fields.version >> 4,
483 			       check->fields.version & 15);
484 			continue;
485 		}
486 		printk(KERN_INFO "PnPBIOS: PnP BIOS version %d.%d, entry 0x%x:0x%x, dseg 0x%x\n",
487                        check->fields.version >> 4, check->fields.version & 15,
488 		       check->fields.pm16cseg, check->fields.pm16offset,
489 		       check->fields.pm16dseg);
490 		pnp_bios_install = check;
491 		return 1;
492 	}
493 
494 	printk(KERN_INFO "PnPBIOS: PnP BIOS support was not detected.\n");
495 	return 0;
496 }
497 
498 static int __init exploding_pnp_bios(struct dmi_system_id *d)
499 {
500 	printk(KERN_WARNING "%s detected. Disabling PnPBIOS\n", d->ident);
501 	return 0;
502 }
503 
504 static struct dmi_system_id pnpbios_dmi_table[] __initdata = {
505 	{	/* PnPBIOS GPF on boot */
506 		.callback = exploding_pnp_bios,
507 		.ident = "Higraded P14H",
508 		.matches = {
509 			DMI_MATCH(DMI_BIOS_VENDOR, "American Megatrends Inc."),
510 			DMI_MATCH(DMI_BIOS_VERSION, "07.00T"),
511 			DMI_MATCH(DMI_SYS_VENDOR, "Higraded"),
512 			DMI_MATCH(DMI_PRODUCT_NAME, "P14H"),
513 		},
514 	},
515 	{	/* PnPBIOS GPF on boot */
516 		.callback = exploding_pnp_bios,
517 		.ident = "ASUS P4P800",
518 		.matches = {
519 			DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer Inc."),
520 			DMI_MATCH(DMI_BOARD_NAME, "P4P800"),
521 		},
522 	},
523 	{ }
524 };
525 
526 static int __init pnpbios_init(void)
527 {
528 	int ret;
529 
530 #if defined(CONFIG_PPC_MERGE)
531 	if (check_legacy_ioport(PNPBIOS_BASE))
532 		return -ENODEV;
533 #endif
534 	if (pnpbios_disabled || dmi_check_system(pnpbios_dmi_table) ||
535 	    paravirt_enabled()) {
536 		printk(KERN_INFO "PnPBIOS: Disabled\n");
537 		return -ENODEV;
538 	}
539 
540 #ifdef CONFIG_PNPACPI
541 	if (!acpi_disabled && !pnpacpi_disabled) {
542 		pnpbios_disabled = 1;
543 		printk(KERN_INFO "PnPBIOS: Disabled by ACPI PNP\n");
544 		return -ENODEV;
545 	}
546 #endif /* CONFIG_ACPI */
547 
548 	/* scan the system for pnpbios support */
549 	if (!pnpbios_probe_system())
550 		return -ENODEV;
551 
552 	/* make preparations for bios calls */
553 	pnpbios_calls_init(pnp_bios_install);
554 
555 	/* read the node info */
556 	ret = pnp_bios_dev_node_info(&node_info);
557 	if (ret) {
558 		printk(KERN_ERR "PnPBIOS: Unable to get node info.  Aborting.\n");
559 		return ret;
560 	}
561 
562 	/* register with the pnp layer */
563 	ret = pnp_register_protocol(&pnpbios_protocol);
564 	if (ret) {
565 		printk(KERN_ERR "PnPBIOS: Unable to register driver.  Aborting.\n");
566 		return ret;
567 	}
568 
569 	/* start the proc interface */
570 	ret = pnpbios_proc_init();
571 	if (ret)
572 		printk(KERN_ERR "PnPBIOS: Failed to create proc interface.\n");
573 
574 	/* scan for pnpbios devices */
575 	build_devlist();
576 
577 	return 0;
578 }
579 
580 subsys_initcall(pnpbios_init);
581 
582 static int __init pnpbios_thread_init(void)
583 {
584 #if defined(CONFIG_PPC_MERGE)
585 	if (check_legacy_ioport(PNPBIOS_BASE))
586 		return 0;
587 #endif
588 	if (pnpbios_disabled)
589 		return 0;
590 #ifdef CONFIG_HOTPLUG
591 	init_completion(&unload_sem);
592 	if (kernel_thread(pnp_dock_thread, NULL, CLONE_KERNEL) > 0)
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