xref: /openbmc/linux/drivers/pnp/pnpbios/core.c (revision 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2)
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/kobject_uevent.h>
60 #include <linux/completion.h>
61 #include <linux/spinlock.h>
62 #include <linux/dmi.h>
63 #include <linux/delay.h>
64 #include <linux/acpi.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 void *pnpbios_kmalloc(size_t size, int f)
90 {
91 	void *p = kmalloc( size, f );
92 	if ( p == NULL )
93 		printk(KERN_ERR "PnPBIOS: kmalloc() failed\n");
94 	else
95 		memset(p, 0, size);
96 	return p;
97 }
98 
99 /*
100  *
101  * DOCKING FUNCTIONS
102  *
103  */
104 
105 #ifdef CONFIG_HOTPLUG
106 
107 static int unloading = 0;
108 static struct completion unload_sem;
109 
110 /*
111  * (Much of this belongs in a shared routine somewhere)
112  */
113 
114 static int pnp_dock_event(int dock, struct pnp_docking_station_info *info)
115 {
116 	char *argv [3], **envp, *buf, *scratch;
117 	int i = 0, value;
118 
119 	if (!hotplug_path [0])
120 		return -ENOENT;
121 	if (!current->fs->root) {
122 		return -EAGAIN;
123 	}
124 	if (!(envp = (char **) pnpbios_kmalloc (20 * sizeof (char *), GFP_KERNEL))) {
125 		return -ENOMEM;
126 	}
127 	if (!(buf = pnpbios_kmalloc (256, GFP_KERNEL))) {
128 		kfree (envp);
129 		return -ENOMEM;
130 	}
131 
132 	/* only one standardized param to hotplug command: type */
133 	argv [0] = hotplug_path;
134 	argv [1] = "dock";
135 	argv [2] = NULL;
136 
137 	/* minimal command environment */
138 	envp [i++] = "HOME=/";
139 	envp [i++] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin";
140 
141 #ifdef	DEBUG
142 	/* hint that policy agent should enter no-stdout debug mode */
143 	envp [i++] = "DEBUG=kernel";
144 #endif
145 	/* extensible set of named bus-specific parameters,
146 	 * supporting multiple driver selection algorithms.
147 	 */
148 	scratch = buf;
149 
150 	/* action:  add, remove */
151 	envp [i++] = scratch;
152 	scratch += sprintf (scratch, "ACTION=%s", dock?"add":"remove") + 1;
153 
154 	/* Report the ident for the dock */
155 	envp [i++] = scratch;
156 	scratch += sprintf (scratch, "DOCK=%x/%x/%x",
157 		info->location_id, info->serial, info->capabilities);
158 	envp[i] = NULL;
159 
160 	value = call_usermodehelper (argv [0], argv, envp, 0);
161 	kfree (buf);
162 	kfree (envp);
163 	return 0;
164 }
165 
166 /*
167  * Poll the PnP docking at regular intervals
168  */
169 static int pnp_dock_thread(void * unused)
170 {
171 	static struct pnp_docking_station_info now;
172 	int docked = -1, d = 0;
173 	daemonize("kpnpbiosd");
174 	allow_signal(SIGKILL);
175 	while(!unloading && !signal_pending(current))
176 	{
177 		int status;
178 
179 		/*
180 		 * Poll every 2 seconds
181 		 */
182 		msleep_interruptible(2000);
183 
184 		if(signal_pending(current)) {
185 			if (try_to_freeze(PF_FREEZE))
186 				continue;
187 			break;
188 		}
189 
190 		status = pnp_bios_dock_station_info(&now);
191 
192 		switch(status)
193 		{
194 			/*
195 			 * No dock to manage
196 			 */
197 			case PNP_FUNCTION_NOT_SUPPORTED:
198 				complete_and_exit(&unload_sem, 0);
199 			case PNP_SYSTEM_NOT_DOCKED:
200 				d = 0;
201 				break;
202 			case PNP_SUCCESS:
203 				d = 1;
204 				break;
205 			default:
206 				pnpbios_print_status( "pnp_dock_thread", status );
207 				continue;
208 		}
209 		if(d != docked)
210 		{
211 			if(pnp_dock_event(d, &now)==0)
212 			{
213 				docked = d;
214 #if 0
215 				printk(KERN_INFO "PnPBIOS: Docking station %stached\n", docked?"at":"de");
216 #endif
217 			}
218 		}
219 	}
220 	complete_and_exit(&unload_sem, 0);
221 }
222 
223 #endif   /* CONFIG_HOTPLUG */
224 
225 static int pnpbios_get_resources(struct pnp_dev * dev, struct pnp_resource_table * res)
226 {
227 	u8 nodenum = dev->number;
228 	struct pnp_bios_node * node;
229 
230 	/* just in case */
231 	if(!pnpbios_is_dynamic(dev))
232 		return -EPERM;
233 
234 	node = pnpbios_kmalloc(node_info.max_node_size, GFP_KERNEL);
235 	if (!node)
236 		return -1;
237 	if (pnp_bios_get_dev_node(&nodenum, (char )PNPMODE_DYNAMIC, node)) {
238 		kfree(node);
239 		return -ENODEV;
240 	}
241 	pnpbios_read_resources_from_node(res, node);
242 	dev->active = pnp_is_active(dev);
243 	kfree(node);
244 	return 0;
245 }
246 
247 static int pnpbios_set_resources(struct pnp_dev * dev, struct pnp_resource_table * res)
248 {
249 	u8 nodenum = dev->number;
250 	struct pnp_bios_node * node;
251 	int ret;
252 
253 	/* just in case */
254 	if (!pnpbios_is_dynamic(dev))
255 		return -EPERM;
256 
257 	node = pnpbios_kmalloc(node_info.max_node_size, GFP_KERNEL);
258 	if (!node)
259 		return -1;
260 	if (pnp_bios_get_dev_node(&nodenum, (char )PNPMODE_DYNAMIC, node)) {
261 		kfree(node);
262 		return -ENODEV;
263 	}
264 	if(pnpbios_write_resources_to_node(res, node)<0) {
265 		kfree(node);
266 		return -1;
267 	}
268 	ret = pnp_bios_set_dev_node(node->handle, (char)PNPMODE_DYNAMIC, node);
269 	kfree(node);
270 	if (ret > 0)
271 		ret = -1;
272 	return ret;
273 }
274 
275 static void pnpbios_zero_data_stream(struct pnp_bios_node * node)
276 {
277 	unsigned char * p = (char *)node->data;
278 	unsigned char * end = (char *)(node->data + node->size);
279 	unsigned int len;
280 	int i;
281 	while ((char *)p < (char *)end) {
282 		if(p[0] & 0x80) { /* large tag */
283 			len = (p[2] << 8) | p[1];
284 			p += 3;
285 		} else {
286 			if (((p[0]>>3) & 0x0f) == 0x0f)
287 				return;
288 			len = p[0] & 0x07;
289 			p += 1;
290 		}
291 		for (i = 0; i < len; i++)
292 			p[i] = 0;
293 		p += len;
294 	}
295 	printk(KERN_ERR "PnPBIOS: Resource structure did not contain an end tag.\n");
296 }
297 
298 static int pnpbios_disable_resources(struct pnp_dev *dev)
299 {
300 	struct pnp_bios_node * node;
301 	u8 nodenum = dev->number;
302 	int ret;
303 
304 	/* just in case */
305 	if(dev->flags & PNPBIOS_NO_DISABLE || !pnpbios_is_dynamic(dev))
306 		return -EPERM;
307 
308 	node = pnpbios_kmalloc(node_info.max_node_size, GFP_KERNEL);
309 	if (!node)
310 		return -ENOMEM;
311 
312 	if (pnp_bios_get_dev_node(&nodenum, (char )PNPMODE_DYNAMIC, node)) {
313 		kfree(node);
314 		return -ENODEV;
315 	}
316 	pnpbios_zero_data_stream(node);
317 
318 	ret = pnp_bios_set_dev_node(dev->number, (char)PNPMODE_DYNAMIC, node);
319 	kfree(node);
320 	if (ret > 0)
321 		ret = -1;
322 	return ret;
323 }
324 
325 /* PnP Layer support */
326 
327 struct pnp_protocol pnpbios_protocol = {
328 	.name	= "Plug and Play BIOS",
329 	.get	= pnpbios_get_resources,
330 	.set	= pnpbios_set_resources,
331 	.disable = pnpbios_disable_resources,
332 };
333 
334 static int insert_device(struct pnp_dev *dev, struct pnp_bios_node * node)
335 {
336 	struct list_head * pos;
337 	struct pnp_dev * pnp_dev;
338 	struct pnp_id *dev_id;
339 	char id[8];
340 
341 	/* check if the device is already added */
342 	dev->number = node->handle;
343 	list_for_each (pos, &pnpbios_protocol.devices){
344 		pnp_dev = list_entry(pos, struct pnp_dev, protocol_list);
345 		if (dev->number == pnp_dev->number)
346 			return -1;
347 	}
348 
349 	/* set the initial values for the PnP device */
350 	dev_id = pnpbios_kmalloc(sizeof(struct pnp_id), GFP_KERNEL);
351 	if (!dev_id)
352 		return -1;
353 	pnpid32_to_pnpid(node->eisa_id,id);
354 	memcpy(dev_id->id,id,7);
355 	pnp_add_id(dev_id, dev);
356 	pnpbios_parse_data_stream(dev, node);
357 	dev->active = pnp_is_active(dev);
358 	dev->flags = node->flags;
359 	if (!(dev->flags & PNPBIOS_NO_CONFIG))
360 		dev->capabilities |= PNP_CONFIGURABLE;
361 	if (!(dev->flags & PNPBIOS_NO_DISABLE))
362 		dev->capabilities |= PNP_DISABLE;
363 	dev->capabilities |= PNP_READ;
364 	if (pnpbios_is_dynamic(dev))
365 		dev->capabilities |= PNP_WRITE;
366 	if (dev->flags & PNPBIOS_REMOVABLE)
367 		dev->capabilities |= PNP_REMOVABLE;
368 	dev->protocol = &pnpbios_protocol;
369 
370 	/* clear out the damaged flags */
371 	if (!dev->active)
372 		pnp_init_resource_table(&dev->res);
373 
374 	pnp_add_device(dev);
375 	pnpbios_interface_attach_device(node);
376 
377 	return 0;
378 }
379 
380 static void __init build_devlist(void)
381 {
382 	u8 nodenum;
383 	unsigned int nodes_got = 0;
384 	unsigned int devs = 0;
385 	struct pnp_bios_node *node;
386 	struct pnp_dev *dev;
387 
388 	node = pnpbios_kmalloc(node_info.max_node_size, GFP_KERNEL);
389 	if (!node)
390 		return;
391 
392 	for(nodenum=0; nodenum<0xff; ) {
393 		u8 thisnodenum = nodenum;
394 		/* eventually we will want to use PNPMODE_STATIC here but for now
395 		 * dynamic will help us catch buggy bioses to add to the blacklist.
396 		 */
397 		if (!pnpbios_dont_use_current_config) {
398 			if (pnp_bios_get_dev_node(&nodenum, (char )PNPMODE_DYNAMIC, node))
399 				break;
400 		} else {
401 			if (pnp_bios_get_dev_node(&nodenum, (char )PNPMODE_STATIC, node))
402 				break;
403 		}
404 		nodes_got++;
405 		dev =  pnpbios_kmalloc(sizeof (struct pnp_dev), GFP_KERNEL);
406 		if (!dev)
407 			break;
408 		if(insert_device(dev,node)<0)
409 			kfree(dev);
410 		else
411 			devs++;
412 		if (nodenum <= thisnodenum) {
413 			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);
414 			break;
415 		}
416 	}
417 	kfree(node);
418 
419 	printk(KERN_INFO "PnPBIOS: %i node%s reported by PnP BIOS; %i recorded by driver\n",
420 		nodes_got, nodes_got != 1 ? "s" : "", devs);
421 }
422 
423 /*
424  *
425  * INIT AND EXIT
426  *
427  */
428 
429 static int pnpbios_disabled; /* = 0 */
430 int pnpbios_dont_use_current_config; /* = 0 */
431 
432 #ifndef MODULE
433 static int __init pnpbios_setup(char *str)
434 {
435 	int invert;
436 
437 	while ((str != NULL) && (*str != '\0')) {
438 		if (strncmp(str, "off", 3) == 0)
439 			pnpbios_disabled=1;
440 		if (strncmp(str, "on", 2) == 0)
441 			pnpbios_disabled=0;
442 		invert = (strncmp(str, "no-", 3) == 0);
443 		if (invert)
444 			str += 3;
445 		if (strncmp(str, "curr", 4) == 0)
446 			pnpbios_dont_use_current_config = invert;
447 		str = strchr(str, ',');
448 		if (str != NULL)
449 			str += strspn(str, ", \t");
450 	}
451 
452 	return 1;
453 }
454 
455 __setup("pnpbios=", pnpbios_setup);
456 #endif
457 
458 /* PnP BIOS signature: "$PnP" */
459 #define PNP_SIGNATURE   (('$' << 0) + ('P' << 8) + ('n' << 16) + ('P' << 24))
460 
461 static int __init pnpbios_probe_system(void)
462 {
463 	union pnp_bios_install_struct *check;
464 	u8 sum;
465 	int length, i;
466 
467 	printk(KERN_INFO "PnPBIOS: Scanning system for PnP BIOS support...\n");
468 
469 	/*
470  	 * Search the defined area (0xf0000-0xffff0) for a valid PnP BIOS
471 	 * structure and, if one is found, sets up the selectors and
472 	 * entry points
473 	 */
474 	for (check = (union pnp_bios_install_struct *) __va(0xf0000);
475 	     check < (union pnp_bios_install_struct *) __va(0xffff0);
476 	     check = (void *)check + 16) {
477 		if (check->fields.signature != PNP_SIGNATURE)
478 			continue;
479 		printk(KERN_INFO "PnPBIOS: Found PnP BIOS installation structure at 0x%p\n", check);
480 		length = check->fields.length;
481 		if (!length) {
482 			printk(KERN_ERR "PnPBIOS: installation structure is invalid, skipping\n");
483 			continue;
484 		}
485 		for (sum = 0, i = 0; i < length; i++)
486 			sum += check->chars[i];
487 		if (sum) {
488 			printk(KERN_ERR "PnPBIOS: installation structure is corrupted, skipping\n");
489 			continue;
490 		}
491 		if (check->fields.version < 0x10) {
492 			printk(KERN_WARNING "PnPBIOS: PnP BIOS version %d.%d is not supported\n",
493 			       check->fields.version >> 4,
494 			       check->fields.version & 15);
495 			continue;
496 		}
497 		printk(KERN_INFO "PnPBIOS: PnP BIOS version %d.%d, entry 0x%x:0x%x, dseg 0x%x\n",
498                        check->fields.version >> 4, check->fields.version & 15,
499 		       check->fields.pm16cseg, check->fields.pm16offset,
500 		       check->fields.pm16dseg);
501 		pnp_bios_install = check;
502 		return 1;
503 	}
504 
505 	printk(KERN_INFO "PnPBIOS: PnP BIOS support was not detected.\n");
506 	return 0;
507 }
508 
509 static int __init exploding_pnp_bios(struct dmi_system_id *d)
510 {
511 	printk(KERN_WARNING "%s detected. Disabling PnPBIOS\n", d->ident);
512 	return 0;
513 }
514 
515 static struct dmi_system_id pnpbios_dmi_table[] = {
516 	{	/* PnPBIOS GPF on boot */
517 		.callback = exploding_pnp_bios,
518 		.ident = "Higraded P14H",
519 		.matches = {
520 			DMI_MATCH(DMI_BIOS_VENDOR, "American Megatrends Inc."),
521 			DMI_MATCH(DMI_BIOS_VERSION, "07.00T"),
522 			DMI_MATCH(DMI_SYS_VENDOR, "Higraded"),
523 			DMI_MATCH(DMI_PRODUCT_NAME, "P14H"),
524 		},
525 	},
526 	{	/* PnPBIOS GPF on boot */
527 		.callback = exploding_pnp_bios,
528 		.ident = "ASUS P4P800",
529 		.matches = {
530 			DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer Inc."),
531 			DMI_MATCH(DMI_BOARD_NAME, "P4P800"),
532 		},
533 	},
534 	{ }
535 };
536 
537 static int __init pnpbios_init(void)
538 {
539 	int ret;
540 
541 	if (pnpbios_disabled || dmi_check_system(pnpbios_dmi_table)) {
542 		printk(KERN_INFO "PnPBIOS: Disabled\n");
543 		return -ENODEV;
544 	}
545 
546 #ifdef CONFIG_PNPACPI
547 	if (!acpi_disabled && !pnpacpi_disabled) {
548 		pnpbios_disabled = 1;
549 		printk(KERN_INFO "PnPBIOS: Disabled by ACPI PNP\n");
550 		return -ENODEV;
551 	}
552 #endif /* CONFIG_ACPI */
553 
554 	/* scan the system for pnpbios support */
555 	if (!pnpbios_probe_system())
556 		return -ENODEV;
557 
558 	/* make preparations for bios calls */
559 	pnpbios_calls_init(pnp_bios_install);
560 
561 	/* read the node info */
562 	ret = pnp_bios_dev_node_info(&node_info);
563 	if (ret) {
564 		printk(KERN_ERR "PnPBIOS: Unable to get node info.  Aborting.\n");
565 		return ret;
566 	}
567 
568 	/* register with the pnp layer */
569 	ret = pnp_register_protocol(&pnpbios_protocol);
570 	if (ret) {
571 		printk(KERN_ERR "PnPBIOS: Unable to register driver.  Aborting.\n");
572 		return ret;
573 	}
574 
575 	/* start the proc interface */
576 	ret = pnpbios_proc_init();
577 	if (ret)
578 		printk(KERN_ERR "PnPBIOS: Failed to create proc interface.\n");
579 
580 	/* scan for pnpbios devices */
581 	build_devlist();
582 
583 	return 0;
584 }
585 
586 subsys_initcall(pnpbios_init);
587 
588 static int __init pnpbios_thread_init(void)
589 {
590 	if (pnpbios_disabled)
591 		return 0;
592 #ifdef CONFIG_HOTPLUG
593 	init_completion(&unload_sem);
594 	if (kernel_thread(pnp_dock_thread, NULL, CLONE_KERNEL) > 0)
595 		unloading = 0;
596 #endif
597 	return 0;
598 }
599 
600 #ifndef MODULE
601 
602 /* init/main.c calls pnpbios_init early */
603 
604 /* Start the kernel thread later: */
605 module_init(pnpbios_thread_init);
606 
607 #else
608 
609 /*
610  * N.B.: Building pnpbios as a module hasn't been fully implemented
611  */
612 
613 MODULE_LICENSE("GPL");
614 
615 static int __init pnpbios_init_all(void)
616 {
617 	int r;
618 
619 	r = pnpbios_init();
620 	if (r)
621 		return r;
622 	r = pnpbios_thread_init();
623 	if (r)
624 		return r;
625 	return 0;
626 }
627 
628 static void __exit pnpbios_exit(void)
629 {
630 #ifdef CONFIG_HOTPLUG
631 	unloading = 1;
632 	wait_for_completion(&unload_sem);
633 #endif
634 	pnpbios_proc_exit();
635 	/* We ought to free resources here */
636 	return;
637 }
638 
639 module_init(pnpbios_init_all);
640 module_exit(pnpbios_exit);
641 
642 #endif
643 
644 EXPORT_SYMBOL(pnpbios_protocol);
645