xref: /linux/drivers/pnp/pnpbios/core.c (revision e58e871becec2d3b04ed91c0c16fe8deac9c9dfa)
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/init.h>
50 #include <linux/linkage.h>
51 #include <linux/kernel.h>
52 #include <linux/device.h>
53 #include <linux/pnp.h>
54 #include <linux/mm.h>
55 #include <linux/smp.h>
56 #include <linux/slab.h>
57 #include <linux/completion.h>
58 #include <linux/spinlock.h>
59 #include <linux/dmi.h>
60 #include <linux/delay.h>
61 #include <linux/acpi.h>
62 #include <linux/freezer.h>
63 #include <linux/kmod.h>
64 #include <linux/kthread.h>
65 
66 #include <asm/page.h>
67 #include <asm/desc.h>
68 #include <asm/byteorder.h>
69 
70 #include "../base.h"
71 #include "pnpbios.h"
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 static struct completion unload_sem;
95 
96 /*
97  * (Much of this belongs in a shared routine somewhere)
98  */
99 static int pnp_dock_event(int dock, struct pnp_docking_station_info *info)
100 {
101 	static char const sbin_pnpbios[] = "/sbin/pnpbios";
102 	char *argv[3], **envp, *buf, *scratch;
103 	int i = 0, value;
104 
105 	if (!(envp = kcalloc(20, sizeof(char *), GFP_KERNEL)))
106 		return -ENOMEM;
107 	if (!(buf = kzalloc(256, GFP_KERNEL))) {
108 		kfree(envp);
109 		return -ENOMEM;
110 	}
111 
112 	/* FIXME: if there are actual users of this, it should be
113 	 * integrated into the driver core and use the usual infrastructure
114 	 * like sysfs and uevents
115 	 */
116 	argv[0] = (char *)sbin_pnpbios;
117 	argv[1] = "dock";
118 	argv[2] = NULL;
119 
120 	/* minimal command environment */
121 	envp[i++] = "HOME=/";
122 	envp[i++] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin";
123 
124 #ifdef	DEBUG
125 	/* hint that policy agent should enter no-stdout debug mode */
126 	envp[i++] = "DEBUG=kernel";
127 #endif
128 	/* extensible set of named bus-specific parameters,
129 	 * supporting multiple driver selection algorithms.
130 	 */
131 	scratch = buf;
132 
133 	/* action:  add, remove */
134 	envp[i++] = scratch;
135 	scratch += sprintf(scratch, "ACTION=%s", dock ? "add" : "remove") + 1;
136 
137 	/* Report the ident for the dock */
138 	envp[i++] = scratch;
139 	scratch += sprintf(scratch, "DOCK=%x/%x/%x",
140 			   info->location_id, info->serial, info->capabilities);
141 	envp[i] = NULL;
142 
143 	value = call_usermodehelper(sbin_pnpbios, argv, envp, UMH_WAIT_EXEC);
144 	kfree(buf);
145 	kfree(envp);
146 	return 0;
147 }
148 
149 /*
150  * Poll the PnP docking at regular intervals
151  */
152 static int pnp_dock_thread(void *unused)
153 {
154 	static struct pnp_docking_station_info now;
155 	int docked = -1, d = 0;
156 
157 	set_freezable();
158 	while (1) {
159 		int status;
160 
161 		/*
162 		 * Poll every 2 seconds
163 		 */
164 		msleep_interruptible(2000);
165 
166 		if (try_to_freeze())
167 			continue;
168 
169 		status = pnp_bios_dock_station_info(&now);
170 
171 		switch (status) {
172 			/*
173 			 * No dock to manage
174 			 */
175 		case PNP_FUNCTION_NOT_SUPPORTED:
176 			complete_and_exit(&unload_sem, 0);
177 		case PNP_SYSTEM_NOT_DOCKED:
178 			d = 0;
179 			break;
180 		case PNP_SUCCESS:
181 			d = 1;
182 			break;
183 		default:
184 			pnpbios_print_status("pnp_dock_thread", status);
185 			printk(KERN_WARNING "PnPBIOS: disabling dock monitoring.\n");
186 			complete_and_exit(&unload_sem, 0);
187 		}
188 		if (d != docked) {
189 			if (pnp_dock_event(d, &now) == 0) {
190 				docked = d;
191 #if 0
192 				printk(KERN_INFO
193 				       "PnPBIOS: Docking station %stached\n",
194 				       docked ? "at" : "de");
195 #endif
196 			}
197 		}
198 	}
199 	complete_and_exit(&unload_sem, 0);
200 }
201 
202 static int pnpbios_get_resources(struct pnp_dev *dev)
203 {
204 	u8 nodenum = dev->number;
205 	struct pnp_bios_node *node;
206 
207 	if (!pnpbios_is_dynamic(dev))
208 		return -EPERM;
209 
210 	pnp_dbg(&dev->dev, "get resources\n");
211 	node = kzalloc(node_info.max_node_size, GFP_KERNEL);
212 	if (!node)
213 		return -1;
214 	if (pnp_bios_get_dev_node(&nodenum, (char)PNPMODE_DYNAMIC, node)) {
215 		kfree(node);
216 		return -ENODEV;
217 	}
218 	pnpbios_read_resources_from_node(dev, node);
219 	dev->active = pnp_is_active(dev);
220 	kfree(node);
221 	return 0;
222 }
223 
224 static int pnpbios_set_resources(struct pnp_dev *dev)
225 {
226 	u8 nodenum = dev->number;
227 	struct pnp_bios_node *node;
228 	int ret;
229 
230 	if (!pnpbios_is_dynamic(dev))
231 		return -EPERM;
232 
233 	pnp_dbg(&dev->dev, "set resources\n");
234 	node = kzalloc(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 	if (pnpbios_write_resources_to_node(dev, node) < 0) {
242 		kfree(node);
243 		return -1;
244 	}
245 	ret = pnp_bios_set_dev_node(node->handle, (char)PNPMODE_DYNAMIC, node);
246 	kfree(node);
247 	if (ret > 0)
248 		ret = -1;
249 	return ret;
250 }
251 
252 static void pnpbios_zero_data_stream(struct pnp_bios_node *node)
253 {
254 	unsigned char *p = (char *)node->data;
255 	unsigned char *end = (char *)(node->data + node->size);
256 	unsigned int len;
257 	int i;
258 
259 	while ((char *)p < (char *)end) {
260 		if (p[0] & 0x80) {	/* large tag */
261 			len = (p[2] << 8) | p[1];
262 			p += 3;
263 		} else {
264 			if (((p[0] >> 3) & 0x0f) == 0x0f)
265 				return;
266 			len = p[0] & 0x07;
267 			p += 1;
268 		}
269 		for (i = 0; i < len; i++)
270 			p[i] = 0;
271 		p += len;
272 	}
273 	printk(KERN_ERR
274 	       "PnPBIOS: Resource structure did not contain an end tag.\n");
275 }
276 
277 static int pnpbios_disable_resources(struct pnp_dev *dev)
278 {
279 	struct pnp_bios_node *node;
280 	u8 nodenum = dev->number;
281 	int ret;
282 
283 	if (dev->flags & PNPBIOS_NO_DISABLE || !pnpbios_is_dynamic(dev))
284 		return -EPERM;
285 
286 	node = kzalloc(node_info.max_node_size, GFP_KERNEL);
287 	if (!node)
288 		return -ENOMEM;
289 
290 	if (pnp_bios_get_dev_node(&nodenum, (char)PNPMODE_DYNAMIC, node)) {
291 		kfree(node);
292 		return -ENODEV;
293 	}
294 	pnpbios_zero_data_stream(node);
295 
296 	ret = pnp_bios_set_dev_node(dev->number, (char)PNPMODE_DYNAMIC, node);
297 	kfree(node);
298 	if (ret > 0)
299 		ret = -1;
300 	return ret;
301 }
302 
303 /* PnP Layer support */
304 
305 struct pnp_protocol pnpbios_protocol = {
306 	.name = "Plug and Play BIOS",
307 	.get = pnpbios_get_resources,
308 	.set = pnpbios_set_resources,
309 	.disable = pnpbios_disable_resources,
310 };
311 
312 static int __init insert_device(struct pnp_bios_node *node)
313 {
314 	struct list_head *pos;
315 	struct pnp_dev *dev;
316 	char id[8];
317 	int error;
318 
319 	/* check if the device is already added */
320 	list_for_each(pos, &pnpbios_protocol.devices) {
321 		dev = list_entry(pos, struct pnp_dev, protocol_list);
322 		if (dev->number == node->handle)
323 			return -EEXIST;
324 	}
325 
326 	pnp_eisa_id_to_string(node->eisa_id & PNP_EISA_ID_MASK, id);
327 	dev = pnp_alloc_dev(&pnpbios_protocol, node->handle, id);
328 	if (!dev)
329 		return -ENOMEM;
330 
331 	pnpbios_parse_data_stream(dev, node);
332 	dev->active = pnp_is_active(dev);
333 	dev->flags = node->flags;
334 	if (!(dev->flags & PNPBIOS_NO_CONFIG))
335 		dev->capabilities |= PNP_CONFIGURABLE;
336 	if (!(dev->flags & PNPBIOS_NO_DISABLE) && pnpbios_is_dynamic(dev))
337 		dev->capabilities |= PNP_DISABLE;
338 	dev->capabilities |= PNP_READ;
339 	if (pnpbios_is_dynamic(dev))
340 		dev->capabilities |= PNP_WRITE;
341 	if (dev->flags & PNPBIOS_REMOVABLE)
342 		dev->capabilities |= PNP_REMOVABLE;
343 
344 	/* clear out the damaged flags */
345 	if (!dev->active)
346 		pnp_init_resources(dev);
347 
348 	error = pnp_add_device(dev);
349 	if (error) {
350 		put_device(&dev->dev);
351 		return error;
352 	}
353 
354 	pnpbios_interface_attach_device(node);
355 
356 	return 0;
357 }
358 
359 static void __init build_devlist(void)
360 {
361 	u8 nodenum;
362 	unsigned int nodes_got = 0;
363 	unsigned int devs = 0;
364 	struct pnp_bios_node *node;
365 
366 	node = kzalloc(node_info.max_node_size, GFP_KERNEL);
367 	if (!node)
368 		return;
369 
370 	for (nodenum = 0; nodenum < 0xff;) {
371 		u8 thisnodenum = nodenum;
372 		/* eventually we will want to use PNPMODE_STATIC here but for now
373 		 * dynamic will help us catch buggy bioses to add to the blacklist.
374 		 */
375 		if (!pnpbios_dont_use_current_config) {
376 			if (pnp_bios_get_dev_node
377 			    (&nodenum, (char)PNPMODE_DYNAMIC, node))
378 				break;
379 		} else {
380 			if (pnp_bios_get_dev_node
381 			    (&nodenum, (char)PNPMODE_STATIC, node))
382 				break;
383 		}
384 		nodes_got++;
385 		if (insert_device(node) == 0)
386 			devs++;
387 		if (nodenum <= thisnodenum) {
388 			printk(KERN_ERR
389 			       "PnPBIOS: build_devlist: Node number 0x%x is out of sequence following node 0x%x. Aborting.\n",
390 			       (unsigned int)nodenum,
391 			       (unsigned int)thisnodenum);
392 			break;
393 		}
394 	}
395 	kfree(node);
396 
397 	printk(KERN_INFO
398 	       "PnPBIOS: %i node%s reported by PnP BIOS; %i recorded by driver\n",
399 	       nodes_got, nodes_got != 1 ? "s" : "", devs);
400 }
401 
402 /*
403  *
404  * INIT AND EXIT
405  *
406  */
407 
408 static int pnpbios_disabled;
409 int pnpbios_dont_use_current_config;
410 
411 static int __init pnpbios_setup(char *str)
412 {
413 	int invert;
414 
415 	while ((str != NULL) && (*str != '\0')) {
416 		if (strncmp(str, "off", 3) == 0)
417 			pnpbios_disabled = 1;
418 		if (strncmp(str, "on", 2) == 0)
419 			pnpbios_disabled = 0;
420 		invert = (strncmp(str, "no-", 3) == 0);
421 		if (invert)
422 			str += 3;
423 		if (strncmp(str, "curr", 4) == 0)
424 			pnpbios_dont_use_current_config = invert;
425 		str = strchr(str, ',');
426 		if (str != NULL)
427 			str += strspn(str, ", \t");
428 	}
429 
430 	return 1;
431 }
432 
433 __setup("pnpbios=", pnpbios_setup);
434 
435 /* PnP BIOS signature: "$PnP" */
436 #define PNP_SIGNATURE   (('$' << 0) + ('P' << 8) + ('n' << 16) + ('P' << 24))
437 
438 static int __init pnpbios_probe_system(void)
439 {
440 	union pnp_bios_install_struct *check;
441 	u8 sum;
442 	int length, i;
443 
444 	printk(KERN_INFO "PnPBIOS: Scanning system for PnP BIOS support...\n");
445 
446 	/*
447 	 * Search the defined area (0xf0000-0xffff0) for a valid PnP BIOS
448 	 * structure and, if one is found, sets up the selectors and
449 	 * entry points
450 	 */
451 	for (check = (union pnp_bios_install_struct *)__va(0xf0000);
452 	     check < (union pnp_bios_install_struct *)__va(0xffff0);
453 	     check = (void *)check + 16) {
454 		if (check->fields.signature != PNP_SIGNATURE)
455 			continue;
456 		printk(KERN_INFO
457 		       "PnPBIOS: Found PnP BIOS installation structure at 0x%p\n",
458 		       check);
459 		length = check->fields.length;
460 		if (!length) {
461 			printk(KERN_ERR
462 			       "PnPBIOS: installation structure is invalid, skipping\n");
463 			continue;
464 		}
465 		for (sum = 0, i = 0; i < length; i++)
466 			sum += check->chars[i];
467 		if (sum) {
468 			printk(KERN_ERR
469 			       "PnPBIOS: installation structure is corrupted, skipping\n");
470 			continue;
471 		}
472 		if (check->fields.version < 0x10) {
473 			printk(KERN_WARNING
474 			       "PnPBIOS: PnP BIOS version %d.%d is not supported\n",
475 			       check->fields.version >> 4,
476 			       check->fields.version & 15);
477 			continue;
478 		}
479 		printk(KERN_INFO
480 		       "PnPBIOS: PnP BIOS version %d.%d, entry 0x%x:0x%x, dseg 0x%x\n",
481 		       check->fields.version >> 4, check->fields.version & 15,
482 		       check->fields.pm16cseg, check->fields.pm16offset,
483 		       check->fields.pm16dseg);
484 		pnp_bios_install = check;
485 		return 1;
486 	}
487 
488 	printk(KERN_INFO "PnPBIOS: PnP BIOS support was not detected.\n");
489 	return 0;
490 }
491 
492 static int __init exploding_pnp_bios(const struct dmi_system_id *d)
493 {
494 	printk(KERN_WARNING "%s detected. Disabling PnPBIOS\n", d->ident);
495 	return 0;
496 }
497 
498 static struct dmi_system_id pnpbios_dmi_table[] __initdata = {
499 	{			/* PnPBIOS GPF on boot */
500 	 .callback = exploding_pnp_bios,
501 	 .ident = "Higraded P14H",
502 	 .matches = {
503 		     DMI_MATCH(DMI_BIOS_VENDOR, "American Megatrends Inc."),
504 		     DMI_MATCH(DMI_BIOS_VERSION, "07.00T"),
505 		     DMI_MATCH(DMI_SYS_VENDOR, "Higraded"),
506 		     DMI_MATCH(DMI_PRODUCT_NAME, "P14H"),
507 		     },
508 	 },
509 	{			/* PnPBIOS GPF on boot */
510 	 .callback = exploding_pnp_bios,
511 	 .ident = "ASUS P4P800",
512 	 .matches = {
513 		     DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer Inc."),
514 		     DMI_MATCH(DMI_BOARD_NAME, "P4P800"),
515 		     },
516 	 },
517 	{}
518 };
519 
520 static int __init pnpbios_init(void)
521 {
522 	int ret;
523 
524 	if (pnpbios_disabled || dmi_check_system(pnpbios_dmi_table) ||
525 	    arch_pnpbios_disabled()) {
526 		printk(KERN_INFO "PnPBIOS: Disabled\n");
527 		return -ENODEV;
528 	}
529 
530 #ifdef CONFIG_PNPACPI
531 	if (!acpi_disabled && !pnpacpi_disabled) {
532 		pnpbios_disabled = 1;
533 		printk(KERN_INFO "PnPBIOS: Disabled by ACPI PNP\n");
534 		return -ENODEV;
535 	}
536 #endif				/* CONFIG_ACPI */
537 
538 	/* scan the system for pnpbios support */
539 	if (!pnpbios_probe_system())
540 		return -ENODEV;
541 
542 	/* make preparations for bios calls */
543 	pnpbios_calls_init(pnp_bios_install);
544 
545 	/* read the node info */
546 	ret = pnp_bios_dev_node_info(&node_info);
547 	if (ret) {
548 		printk(KERN_ERR
549 		       "PnPBIOS: Unable to get node info.  Aborting.\n");
550 		return ret;
551 	}
552 
553 	/* register with the pnp layer */
554 	ret = pnp_register_protocol(&pnpbios_protocol);
555 	if (ret) {
556 		printk(KERN_ERR
557 		       "PnPBIOS: Unable to register driver.  Aborting.\n");
558 		return ret;
559 	}
560 
561 	/* start the proc interface */
562 	ret = pnpbios_proc_init();
563 	if (ret)
564 		printk(KERN_ERR "PnPBIOS: Failed to create proc interface.\n");
565 
566 	/* scan for pnpbios devices */
567 	build_devlist();
568 
569 	pnp_platform_devices = 1;
570 	return 0;
571 }
572 
573 fs_initcall(pnpbios_init);
574 
575 static int __init pnpbios_thread_init(void)
576 {
577 	struct task_struct *task;
578 
579 	if (pnpbios_disabled)
580 		return 0;
581 
582 	init_completion(&unload_sem);
583 	task = kthread_run(pnp_dock_thread, NULL, "kpnpbiosd");
584 	if (IS_ERR(task))
585 		return PTR_ERR(task);
586 
587 	return 0;
588 }
589 
590 /* Start the kernel thread later: */
591 device_initcall(pnpbios_thread_init);
592 
593 EXPORT_SYMBOL(pnpbios_protocol);
594