xref: /linux/drivers/pnp/pnpbios/core.c (revision 6e8331ac6973435b1e7604c30f2ad394035b46e1)
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 
65 #include <asm/page.h>
66 #include <asm/desc.h>
67 #include <asm/system.h>
68 #include <asm/byteorder.h>
69 
70 #include "pnpbios.h"
71 
72 
73 /*
74  *
75  * PnP BIOS INTERFACE
76  *
77  */
78 
79 static union pnp_bios_install_struct * pnp_bios_install = NULL;
80 
81 int pnp_bios_present(void)
82 {
83 	return (pnp_bios_install != NULL);
84 }
85 
86 struct pnp_dev_node_info node_info;
87 
88 /*
89  *
90  * DOCKING FUNCTIONS
91  *
92  */
93 
94 #ifdef CONFIG_HOTPLUG
95 
96 static int unloading = 0;
97 static struct completion unload_sem;
98 
99 /*
100  * (Much of this belongs in a shared routine somewhere)
101  */
102 
103 static int pnp_dock_event(int dock, struct pnp_docking_station_info *info)
104 {
105 	char *argv [3], **envp, *buf, *scratch;
106 	int i = 0, value;
107 
108 	if (!current->fs->root) {
109 		return -EAGAIN;
110 	}
111 	if (!(envp = (char **) kcalloc (20, sizeof (char *), GFP_KERNEL))) {
112 		return -ENOMEM;
113 	}
114 	if (!(buf = kcalloc (1, 256, GFP_KERNEL))) {
115 		kfree (envp);
116 		return -ENOMEM;
117 	}
118 
119 	/* FIXME: if there are actual users of this, it should be integrated into
120 	 * the driver core and use the usual infrastructure like sysfs and uevents */
121 	argv [0] = "/sbin/pnpbios";
122 	argv [1] = "dock";
123 	argv [2] = NULL;
124 
125 	/* minimal command environment */
126 	envp [i++] = "HOME=/";
127 	envp [i++] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin";
128 
129 #ifdef	DEBUG
130 	/* hint that policy agent should enter no-stdout debug mode */
131 	envp [i++] = "DEBUG=kernel";
132 #endif
133 	/* extensible set of named bus-specific parameters,
134 	 * supporting multiple driver selection algorithms.
135 	 */
136 	scratch = buf;
137 
138 	/* action:  add, remove */
139 	envp [i++] = scratch;
140 	scratch += sprintf (scratch, "ACTION=%s", dock?"add":"remove") + 1;
141 
142 	/* Report the ident for the dock */
143 	envp [i++] = scratch;
144 	scratch += sprintf (scratch, "DOCK=%x/%x/%x",
145 		info->location_id, info->serial, info->capabilities);
146 	envp[i] = NULL;
147 
148 	value = call_usermodehelper (argv [0], argv, envp, 0);
149 	kfree (buf);
150 	kfree (envp);
151 	return 0;
152 }
153 
154 /*
155  * Poll the PnP docking at regular intervals
156  */
157 static int pnp_dock_thread(void * unused)
158 {
159 	static struct pnp_docking_station_info now;
160 	int docked = -1, d = 0;
161 	daemonize("kpnpbiosd");
162 	allow_signal(SIGKILL);
163 	while(!unloading && !signal_pending(current))
164 	{
165 		int status;
166 
167 		/*
168 		 * Poll every 2 seconds
169 		 */
170 		msleep_interruptible(2000);
171 
172 		if(signal_pending(current)) {
173 			if (try_to_freeze())
174 				continue;
175 			break;
176 		}
177 
178 		status = pnp_bios_dock_station_info(&now);
179 
180 		switch(status)
181 		{
182 			/*
183 			 * No dock to manage
184 			 */
185 			case PNP_FUNCTION_NOT_SUPPORTED:
186 				complete_and_exit(&unload_sem, 0);
187 			case PNP_SYSTEM_NOT_DOCKED:
188 				d = 0;
189 				break;
190 			case PNP_SUCCESS:
191 				d = 1;
192 				break;
193 			default:
194 				pnpbios_print_status( "pnp_dock_thread", status );
195 				continue;
196 		}
197 		if(d != docked)
198 		{
199 			if(pnp_dock_event(d, &now)==0)
200 			{
201 				docked = d;
202 #if 0
203 				printk(KERN_INFO "PnPBIOS: Docking station %stached\n", docked?"at":"de");
204 #endif
205 			}
206 		}
207 	}
208 	complete_and_exit(&unload_sem, 0);
209 }
210 
211 #endif   /* CONFIG_HOTPLUG */
212 
213 static int pnpbios_get_resources(struct pnp_dev * dev, struct pnp_resource_table * res)
214 {
215 	u8 nodenum = dev->number;
216 	struct pnp_bios_node * node;
217 
218 	/* just in case */
219 	if(!pnpbios_is_dynamic(dev))
220 		return -EPERM;
221 
222 	node = kcalloc(1, node_info.max_node_size, GFP_KERNEL);
223 	if (!node)
224 		return -1;
225 	if (pnp_bios_get_dev_node(&nodenum, (char )PNPMODE_DYNAMIC, node)) {
226 		kfree(node);
227 		return -ENODEV;
228 	}
229 	pnpbios_read_resources_from_node(res, node);
230 	dev->active = pnp_is_active(dev);
231 	kfree(node);
232 	return 0;
233 }
234 
235 static int pnpbios_set_resources(struct pnp_dev * dev, struct pnp_resource_table * res)
236 {
237 	u8 nodenum = dev->number;
238 	struct pnp_bios_node * node;
239 	int ret;
240 
241 	/* just in case */
242 	if (!pnpbios_is_dynamic(dev))
243 		return -EPERM;
244 
245 	node = kcalloc(1, node_info.max_node_size, GFP_KERNEL);
246 	if (!node)
247 		return -1;
248 	if (pnp_bios_get_dev_node(&nodenum, (char )PNPMODE_DYNAMIC, node)) {
249 		kfree(node);
250 		return -ENODEV;
251 	}
252 	if(pnpbios_write_resources_to_node(res, node)<0) {
253 		kfree(node);
254 		return -1;
255 	}
256 	ret = pnp_bios_set_dev_node(node->handle, (char)PNPMODE_DYNAMIC, node);
257 	kfree(node);
258 	if (ret > 0)
259 		ret = -1;
260 	return ret;
261 }
262 
263 static void pnpbios_zero_data_stream(struct pnp_bios_node * node)
264 {
265 	unsigned char * p = (char *)node->data;
266 	unsigned char * end = (char *)(node->data + node->size);
267 	unsigned int len;
268 	int i;
269 	while ((char *)p < (char *)end) {
270 		if(p[0] & 0x80) { /* large tag */
271 			len = (p[2] << 8) | p[1];
272 			p += 3;
273 		} else {
274 			if (((p[0]>>3) & 0x0f) == 0x0f)
275 				return;
276 			len = p[0] & 0x07;
277 			p += 1;
278 		}
279 		for (i = 0; i < len; i++)
280 			p[i] = 0;
281 		p += len;
282 	}
283 	printk(KERN_ERR "PnPBIOS: Resource structure did not contain an end tag.\n");
284 }
285 
286 static int pnpbios_disable_resources(struct pnp_dev *dev)
287 {
288 	struct pnp_bios_node * node;
289 	u8 nodenum = dev->number;
290 	int ret;
291 
292 	/* just in case */
293 	if(dev->flags & PNPBIOS_NO_DISABLE || !pnpbios_is_dynamic(dev))
294 		return -EPERM;
295 
296 	node = kcalloc(1, node_info.max_node_size, GFP_KERNEL);
297 	if (!node)
298 		return -ENOMEM;
299 
300 	if (pnp_bios_get_dev_node(&nodenum, (char )PNPMODE_DYNAMIC, node)) {
301 		kfree(node);
302 		return -ENODEV;
303 	}
304 	pnpbios_zero_data_stream(node);
305 
306 	ret = pnp_bios_set_dev_node(dev->number, (char)PNPMODE_DYNAMIC, node);
307 	kfree(node);
308 	if (ret > 0)
309 		ret = -1;
310 	return ret;
311 }
312 
313 /* PnP Layer support */
314 
315 struct pnp_protocol pnpbios_protocol = {
316 	.name	= "Plug and Play BIOS",
317 	.get	= pnpbios_get_resources,
318 	.set	= pnpbios_set_resources,
319 	.disable = pnpbios_disable_resources,
320 };
321 
322 static int insert_device(struct pnp_dev *dev, struct pnp_bios_node * node)
323 {
324 	struct list_head * pos;
325 	struct pnp_dev * pnp_dev;
326 	struct pnp_id *dev_id;
327 	char id[8];
328 
329 	/* check if the device is already added */
330 	dev->number = node->handle;
331 	list_for_each (pos, &pnpbios_protocol.devices){
332 		pnp_dev = list_entry(pos, struct pnp_dev, protocol_list);
333 		if (dev->number == pnp_dev->number)
334 			return -1;
335 	}
336 
337 	/* set the initial values for the PnP device */
338 	dev_id = kcalloc(1, sizeof(struct pnp_id), GFP_KERNEL);
339 	if (!dev_id)
340 		return -1;
341 	pnpid32_to_pnpid(node->eisa_id,id);
342 	memcpy(dev_id->id,id,7);
343 	pnp_add_id(dev_id, dev);
344 	pnpbios_parse_data_stream(dev, node);
345 	dev->active = pnp_is_active(dev);
346 	dev->flags = node->flags;
347 	if (!(dev->flags & PNPBIOS_NO_CONFIG))
348 		dev->capabilities |= PNP_CONFIGURABLE;
349 	if (!(dev->flags & PNPBIOS_NO_DISABLE) && pnpbios_is_dynamic(dev))
350 		dev->capabilities |= PNP_DISABLE;
351 	dev->capabilities |= PNP_READ;
352 	if (pnpbios_is_dynamic(dev))
353 		dev->capabilities |= PNP_WRITE;
354 	if (dev->flags & PNPBIOS_REMOVABLE)
355 		dev->capabilities |= PNP_REMOVABLE;
356 	dev->protocol = &pnpbios_protocol;
357 
358 	/* clear out the damaged flags */
359 	if (!dev->active)
360 		pnp_init_resource_table(&dev->res);
361 
362 	pnp_add_device(dev);
363 	pnpbios_interface_attach_device(node);
364 
365 	return 0;
366 }
367 
368 static void __init build_devlist(void)
369 {
370 	u8 nodenum;
371 	unsigned int nodes_got = 0;
372 	unsigned int devs = 0;
373 	struct pnp_bios_node *node;
374 	struct pnp_dev *dev;
375 
376 	node = kcalloc(1, node_info.max_node_size, GFP_KERNEL);
377 	if (!node)
378 		return;
379 
380 	for(nodenum=0; nodenum<0xff; ) {
381 		u8 thisnodenum = nodenum;
382 		/* eventually we will want to use PNPMODE_STATIC here but for now
383 		 * dynamic will help us catch buggy bioses to add to the blacklist.
384 		 */
385 		if (!pnpbios_dont_use_current_config) {
386 			if (pnp_bios_get_dev_node(&nodenum, (char )PNPMODE_DYNAMIC, node))
387 				break;
388 		} else {
389 			if (pnp_bios_get_dev_node(&nodenum, (char )PNPMODE_STATIC, node))
390 				break;
391 		}
392 		nodes_got++;
393 		dev =  kcalloc(1, sizeof (struct pnp_dev), GFP_KERNEL);
394 		if (!dev)
395 			break;
396 		if(insert_device(dev,node)<0)
397 			kfree(dev);
398 		else
399 			devs++;
400 		if (nodenum <= thisnodenum) {
401 			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);
402 			break;
403 		}
404 	}
405 	kfree(node);
406 
407 	printk(KERN_INFO "PnPBIOS: %i node%s reported by PnP BIOS; %i recorded by driver\n",
408 		nodes_got, nodes_got != 1 ? "s" : "", devs);
409 }
410 
411 /*
412  *
413  * INIT AND EXIT
414  *
415  */
416 
417 static int pnpbios_disabled; /* = 0 */
418 int pnpbios_dont_use_current_config; /* = 0 */
419 
420 #ifndef MODULE
421 static int __init pnpbios_setup(char *str)
422 {
423 	int invert;
424 
425 	while ((str != NULL) && (*str != '\0')) {
426 		if (strncmp(str, "off", 3) == 0)
427 			pnpbios_disabled=1;
428 		if (strncmp(str, "on", 2) == 0)
429 			pnpbios_disabled=0;
430 		invert = (strncmp(str, "no-", 3) == 0);
431 		if (invert)
432 			str += 3;
433 		if (strncmp(str, "curr", 4) == 0)
434 			pnpbios_dont_use_current_config = invert;
435 		str = strchr(str, ',');
436 		if (str != NULL)
437 			str += strspn(str, ", \t");
438 	}
439 
440 	return 1;
441 }
442 
443 __setup("pnpbios=", pnpbios_setup);
444 #endif
445 
446 /* PnP BIOS signature: "$PnP" */
447 #define PNP_SIGNATURE   (('$' << 0) + ('P' << 8) + ('n' << 16) + ('P' << 24))
448 
449 static int __init pnpbios_probe_system(void)
450 {
451 	union pnp_bios_install_struct *check;
452 	u8 sum;
453 	int length, i;
454 
455 	printk(KERN_INFO "PnPBIOS: Scanning system for PnP BIOS support...\n");
456 
457 	/*
458  	 * Search the defined area (0xf0000-0xffff0) for a valid PnP BIOS
459 	 * structure and, if one is found, sets up the selectors and
460 	 * entry points
461 	 */
462 	for (check = (union pnp_bios_install_struct *) __va(0xf0000);
463 	     check < (union pnp_bios_install_struct *) __va(0xffff0);
464 	     check = (void *)check + 16) {
465 		if (check->fields.signature != PNP_SIGNATURE)
466 			continue;
467 		printk(KERN_INFO "PnPBIOS: Found PnP BIOS installation structure at 0x%p\n", check);
468 		length = check->fields.length;
469 		if (!length) {
470 			printk(KERN_ERR "PnPBIOS: installation structure is invalid, skipping\n");
471 			continue;
472 		}
473 		for (sum = 0, i = 0; i < length; i++)
474 			sum += check->chars[i];
475 		if (sum) {
476 			printk(KERN_ERR "PnPBIOS: installation structure is corrupted, skipping\n");
477 			continue;
478 		}
479 		if (check->fields.version < 0x10) {
480 			printk(KERN_WARNING "PnPBIOS: PnP BIOS version %d.%d is not supported\n",
481 			       check->fields.version >> 4,
482 			       check->fields.version & 15);
483 			continue;
484 		}
485 		printk(KERN_INFO "PnPBIOS: PnP BIOS version %d.%d, entry 0x%x:0x%x, dseg 0x%x\n",
486                        check->fields.version >> 4, check->fields.version & 15,
487 		       check->fields.pm16cseg, check->fields.pm16offset,
488 		       check->fields.pm16dseg);
489 		pnp_bios_install = check;
490 		return 1;
491 	}
492 
493 	printk(KERN_INFO "PnPBIOS: PnP BIOS support was not detected.\n");
494 	return 0;
495 }
496 
497 static int __init exploding_pnp_bios(struct dmi_system_id *d)
498 {
499 	printk(KERN_WARNING "%s detected. Disabling PnPBIOS\n", d->ident);
500 	return 0;
501 }
502 
503 static struct dmi_system_id pnpbios_dmi_table[] __initdata = {
504 	{	/* PnPBIOS GPF on boot */
505 		.callback = exploding_pnp_bios,
506 		.ident = "Higraded P14H",
507 		.matches = {
508 			DMI_MATCH(DMI_BIOS_VENDOR, "American Megatrends Inc."),
509 			DMI_MATCH(DMI_BIOS_VERSION, "07.00T"),
510 			DMI_MATCH(DMI_SYS_VENDOR, "Higraded"),
511 			DMI_MATCH(DMI_PRODUCT_NAME, "P14H"),
512 		},
513 	},
514 	{	/* PnPBIOS GPF on boot */
515 		.callback = exploding_pnp_bios,
516 		.ident = "ASUS P4P800",
517 		.matches = {
518 			DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer Inc."),
519 			DMI_MATCH(DMI_BOARD_NAME, "P4P800"),
520 		},
521 	},
522 	{ }
523 };
524 
525 static int __init pnpbios_init(void)
526 {
527 	int ret;
528 
529 	if (pnpbios_disabled || dmi_check_system(pnpbios_dmi_table)) {
530 		printk(KERN_INFO "PnPBIOS: Disabled\n");
531 		return -ENODEV;
532 	}
533 
534 #ifdef CONFIG_PNPACPI
535 	if (!acpi_disabled && !pnpacpi_disabled) {
536 		pnpbios_disabled = 1;
537 		printk(KERN_INFO "PnPBIOS: Disabled by ACPI PNP\n");
538 		return -ENODEV;
539 	}
540 #endif /* CONFIG_ACPI */
541 
542 	/* scan the system for pnpbios support */
543 	if (!pnpbios_probe_system())
544 		return -ENODEV;
545 
546 	/* make preparations for bios calls */
547 	pnpbios_calls_init(pnp_bios_install);
548 
549 	/* read the node info */
550 	ret = pnp_bios_dev_node_info(&node_info);
551 	if (ret) {
552 		printk(KERN_ERR "PnPBIOS: Unable to get node info.  Aborting.\n");
553 		return ret;
554 	}
555 
556 	/* register with the pnp layer */
557 	ret = pnp_register_protocol(&pnpbios_protocol);
558 	if (ret) {
559 		printk(KERN_ERR "PnPBIOS: Unable to register driver.  Aborting.\n");
560 		return ret;
561 	}
562 
563 	/* start the proc interface */
564 	ret = pnpbios_proc_init();
565 	if (ret)
566 		printk(KERN_ERR "PnPBIOS: Failed to create proc interface.\n");
567 
568 	/* scan for pnpbios devices */
569 	build_devlist();
570 
571 	return 0;
572 }
573 
574 subsys_initcall(pnpbios_init);
575 
576 static int __init pnpbios_thread_init(void)
577 {
578 	if (pnpbios_disabled)
579 		return 0;
580 #ifdef CONFIG_HOTPLUG
581 	init_completion(&unload_sem);
582 	if (kernel_thread(pnp_dock_thread, NULL, CLONE_KERNEL) > 0)
583 		unloading = 0;
584 #endif
585 	return 0;
586 }
587 
588 #ifndef MODULE
589 
590 /* init/main.c calls pnpbios_init early */
591 
592 /* Start the kernel thread later: */
593 module_init(pnpbios_thread_init);
594 
595 #else
596 
597 /*
598  * N.B.: Building pnpbios as a module hasn't been fully implemented
599  */
600 
601 MODULE_LICENSE("GPL");
602 
603 static int __init pnpbios_init_all(void)
604 {
605 	int r;
606 
607 	r = pnpbios_init();
608 	if (r)
609 		return r;
610 	r = pnpbios_thread_init();
611 	if (r)
612 		return r;
613 	return 0;
614 }
615 
616 static void __exit pnpbios_exit(void)
617 {
618 #ifdef CONFIG_HOTPLUG
619 	unloading = 1;
620 	wait_for_completion(&unload_sem);
621 #endif
622 	pnpbios_proc_exit();
623 	/* We ought to free resources here */
624 	return;
625 }
626 
627 module_init(pnpbios_init_all);
628 module_exit(pnpbios_exit);
629 
630 #endif
631 
632 EXPORT_SYMBOL(pnpbios_protocol);
633