xref: /openbmc/linux/drivers/pnp/pnpbios/core.c (revision 9cfc5c90)
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/device.h>
54 #include <linux/pnp.h>
55 #include <linux/mm.h>
56 #include <linux/smp.h>
57 #include <linux/slab.h>
58 #include <linux/completion.h>
59 #include <linux/spinlock.h>
60 #include <linux/dmi.h>
61 #include <linux/delay.h>
62 #include <linux/acpi.h>
63 #include <linux/freezer.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 	char *argv[3], **envp, *buf, *scratch;
102 	int i = 0, value;
103 
104 	if (!(envp = kcalloc(20, sizeof(char *), GFP_KERNEL)))
105 		return -ENOMEM;
106 	if (!(buf = kzalloc(256, GFP_KERNEL))) {
107 		kfree(envp);
108 		return -ENOMEM;
109 	}
110 
111 	/* FIXME: if there are actual users of this, it should be
112 	 * integrated into the driver core and use the usual infrastructure
113 	 * like sysfs and uevents
114 	 */
115 	argv[0] = "/sbin/pnpbios";
116 	argv[1] = "dock";
117 	argv[2] = NULL;
118 
119 	/* minimal command environment */
120 	envp[i++] = "HOME=/";
121 	envp[i++] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin";
122 
123 #ifdef	DEBUG
124 	/* hint that policy agent should enter no-stdout debug mode */
125 	envp[i++] = "DEBUG=kernel";
126 #endif
127 	/* extensible set of named bus-specific parameters,
128 	 * supporting multiple driver selection algorithms.
129 	 */
130 	scratch = buf;
131 
132 	/* action:  add, remove */
133 	envp[i++] = scratch;
134 	scratch += sprintf(scratch, "ACTION=%s", dock ? "add" : "remove") + 1;
135 
136 	/* Report the ident for the dock */
137 	envp[i++] = scratch;
138 	scratch += sprintf(scratch, "DOCK=%x/%x/%x",
139 			   info->location_id, info->serial, info->capabilities);
140 	envp[i] = NULL;
141 
142 	value = call_usermodehelper(argv [0], argv, envp, UMH_WAIT_EXEC);
143 	kfree(buf);
144 	kfree(envp);
145 	return 0;
146 }
147 
148 /*
149  * Poll the PnP docking at regular intervals
150  */
151 static int pnp_dock_thread(void *unused)
152 {
153 	static struct pnp_docking_station_info now;
154 	int docked = -1, d = 0;
155 
156 	set_freezable();
157 	while (1) {
158 		int status;
159 
160 		/*
161 		 * Poll every 2 seconds
162 		 */
163 		msleep_interruptible(2000);
164 
165 		if (try_to_freeze())
166 			continue;
167 
168 		status = pnp_bios_dock_station_info(&now);
169 
170 		switch (status) {
171 			/*
172 			 * No dock to manage
173 			 */
174 		case PNP_FUNCTION_NOT_SUPPORTED:
175 			complete_and_exit(&unload_sem, 0);
176 		case PNP_SYSTEM_NOT_DOCKED:
177 			d = 0;
178 			break;
179 		case PNP_SUCCESS:
180 			d = 1;
181 			break;
182 		default:
183 			pnpbios_print_status("pnp_dock_thread", status);
184 			printk(KERN_WARNING "PnPBIOS: disabling dock monitoring.\n");
185 			complete_and_exit(&unload_sem, 0);
186 		}
187 		if (d != docked) {
188 			if (pnp_dock_event(d, &now) == 0) {
189 				docked = d;
190 #if 0
191 				printk(KERN_INFO
192 				       "PnPBIOS: Docking station %stached\n",
193 				       docked ? "at" : "de");
194 #endif
195 			}
196 		}
197 	}
198 	complete_and_exit(&unload_sem, 0);
199 }
200 
201 static int pnpbios_get_resources(struct pnp_dev *dev)
202 {
203 	u8 nodenum = dev->number;
204 	struct pnp_bios_node *node;
205 
206 	if (!pnpbios_is_dynamic(dev))
207 		return -EPERM;
208 
209 	pnp_dbg(&dev->dev, "get resources\n");
210 	node = kzalloc(node_info.max_node_size, GFP_KERNEL);
211 	if (!node)
212 		return -1;
213 	if (pnp_bios_get_dev_node(&nodenum, (char)PNPMODE_DYNAMIC, node)) {
214 		kfree(node);
215 		return -ENODEV;
216 	}
217 	pnpbios_read_resources_from_node(dev, node);
218 	dev->active = pnp_is_active(dev);
219 	kfree(node);
220 	return 0;
221 }
222 
223 static int pnpbios_set_resources(struct pnp_dev *dev)
224 {
225 	u8 nodenum = dev->number;
226 	struct pnp_bios_node *node;
227 	int ret;
228 
229 	if (!pnpbios_is_dynamic(dev))
230 		return -EPERM;
231 
232 	pnp_dbg(&dev->dev, "set resources\n");
233 	node = kzalloc(node_info.max_node_size, GFP_KERNEL);
234 	if (!node)
235 		return -1;
236 	if (pnp_bios_get_dev_node(&nodenum, (char)PNPMODE_DYNAMIC, node)) {
237 		kfree(node);
238 		return -ENODEV;
239 	}
240 	if (pnpbios_write_resources_to_node(dev, node) < 0) {
241 		kfree(node);
242 		return -1;
243 	}
244 	ret = pnp_bios_set_dev_node(node->handle, (char)PNPMODE_DYNAMIC, node);
245 	kfree(node);
246 	if (ret > 0)
247 		ret = -1;
248 	return ret;
249 }
250 
251 static void pnpbios_zero_data_stream(struct pnp_bios_node *node)
252 {
253 	unsigned char *p = (char *)node->data;
254 	unsigned char *end = (char *)(node->data + node->size);
255 	unsigned int len;
256 	int i;
257 
258 	while ((char *)p < (char *)end) {
259 		if (p[0] & 0x80) {	/* large tag */
260 			len = (p[2] << 8) | p[1];
261 			p += 3;
262 		} else {
263 			if (((p[0] >> 3) & 0x0f) == 0x0f)
264 				return;
265 			len = p[0] & 0x07;
266 			p += 1;
267 		}
268 		for (i = 0; i < len; i++)
269 			p[i] = 0;
270 		p += len;
271 	}
272 	printk(KERN_ERR
273 	       "PnPBIOS: Resource structure did not contain an end tag.\n");
274 }
275 
276 static int pnpbios_disable_resources(struct pnp_dev *dev)
277 {
278 	struct pnp_bios_node *node;
279 	u8 nodenum = dev->number;
280 	int ret;
281 
282 	if (dev->flags & PNPBIOS_NO_DISABLE || !pnpbios_is_dynamic(dev))
283 		return -EPERM;
284 
285 	node = kzalloc(node_info.max_node_size, GFP_KERNEL);
286 	if (!node)
287 		return -ENOMEM;
288 
289 	if (pnp_bios_get_dev_node(&nodenum, (char)PNPMODE_DYNAMIC, node)) {
290 		kfree(node);
291 		return -ENODEV;
292 	}
293 	pnpbios_zero_data_stream(node);
294 
295 	ret = pnp_bios_set_dev_node(dev->number, (char)PNPMODE_DYNAMIC, node);
296 	kfree(node);
297 	if (ret > 0)
298 		ret = -1;
299 	return ret;
300 }
301 
302 /* PnP Layer support */
303 
304 struct pnp_protocol pnpbios_protocol = {
305 	.name = "Plug and Play BIOS",
306 	.get = pnpbios_get_resources,
307 	.set = pnpbios_set_resources,
308 	.disable = pnpbios_disable_resources,
309 };
310 
311 static int __init insert_device(struct pnp_bios_node *node)
312 {
313 	struct list_head *pos;
314 	struct pnp_dev *dev;
315 	char id[8];
316 	int error;
317 
318 	/* check if the device is already added */
319 	list_for_each(pos, &pnpbios_protocol.devices) {
320 		dev = list_entry(pos, struct pnp_dev, protocol_list);
321 		if (dev->number == node->handle)
322 			return -EEXIST;
323 	}
324 
325 	pnp_eisa_id_to_string(node->eisa_id & PNP_EISA_ID_MASK, id);
326 	dev = pnp_alloc_dev(&pnpbios_protocol, node->handle, id);
327 	if (!dev)
328 		return -ENOMEM;
329 
330 	pnpbios_parse_data_stream(dev, node);
331 	dev->active = pnp_is_active(dev);
332 	dev->flags = node->flags;
333 	if (!(dev->flags & PNPBIOS_NO_CONFIG))
334 		dev->capabilities |= PNP_CONFIGURABLE;
335 	if (!(dev->flags & PNPBIOS_NO_DISABLE) && pnpbios_is_dynamic(dev))
336 		dev->capabilities |= PNP_DISABLE;
337 	dev->capabilities |= PNP_READ;
338 	if (pnpbios_is_dynamic(dev))
339 		dev->capabilities |= PNP_WRITE;
340 	if (dev->flags & PNPBIOS_REMOVABLE)
341 		dev->capabilities |= PNP_REMOVABLE;
342 
343 	/* clear out the damaged flags */
344 	if (!dev->active)
345 		pnp_init_resources(dev);
346 
347 	error = pnp_add_device(dev);
348 	if (error) {
349 		put_device(&dev->dev);
350 		return error;
351 	}
352 
353 	pnpbios_interface_attach_device(node);
354 
355 	return 0;
356 }
357 
358 static void __init build_devlist(void)
359 {
360 	u8 nodenum;
361 	unsigned int nodes_got = 0;
362 	unsigned int devs = 0;
363 	struct pnp_bios_node *node;
364 
365 	node = kzalloc(node_info.max_node_size, GFP_KERNEL);
366 	if (!node)
367 		return;
368 
369 	for (nodenum = 0; nodenum < 0xff;) {
370 		u8 thisnodenum = nodenum;
371 		/* eventually we will want to use PNPMODE_STATIC here but for now
372 		 * dynamic will help us catch buggy bioses to add to the blacklist.
373 		 */
374 		if (!pnpbios_dont_use_current_config) {
375 			if (pnp_bios_get_dev_node
376 			    (&nodenum, (char)PNPMODE_DYNAMIC, node))
377 				break;
378 		} else {
379 			if (pnp_bios_get_dev_node
380 			    (&nodenum, (char)PNPMODE_STATIC, node))
381 				break;
382 		}
383 		nodes_got++;
384 		if (insert_device(node) == 0)
385 			devs++;
386 		if (nodenum <= thisnodenum) {
387 			printk(KERN_ERR
388 			       "PnPBIOS: build_devlist: Node number 0x%x is out of sequence following node 0x%x. Aborting.\n",
389 			       (unsigned int)nodenum,
390 			       (unsigned int)thisnodenum);
391 			break;
392 		}
393 	}
394 	kfree(node);
395 
396 	printk(KERN_INFO
397 	       "PnPBIOS: %i node%s reported by PnP BIOS; %i recorded by driver\n",
398 	       nodes_got, nodes_got != 1 ? "s" : "", devs);
399 }
400 
401 /*
402  *
403  * INIT AND EXIT
404  *
405  */
406 
407 static int pnpbios_disabled;
408 int pnpbios_dont_use_current_config;
409 
410 static int __init pnpbios_setup(char *str)
411 {
412 	int invert;
413 
414 	while ((str != NULL) && (*str != '\0')) {
415 		if (strncmp(str, "off", 3) == 0)
416 			pnpbios_disabled = 1;
417 		if (strncmp(str, "on", 2) == 0)
418 			pnpbios_disabled = 0;
419 		invert = (strncmp(str, "no-", 3) == 0);
420 		if (invert)
421 			str += 3;
422 		if (strncmp(str, "curr", 4) == 0)
423 			pnpbios_dont_use_current_config = invert;
424 		str = strchr(str, ',');
425 		if (str != NULL)
426 			str += strspn(str, ", \t");
427 	}
428 
429 	return 1;
430 }
431 
432 __setup("pnpbios=", pnpbios_setup);
433 
434 /* PnP BIOS signature: "$PnP" */
435 #define PNP_SIGNATURE   (('$' << 0) + ('P' << 8) + ('n' << 16) + ('P' << 24))
436 
437 static int __init pnpbios_probe_system(void)
438 {
439 	union pnp_bios_install_struct *check;
440 	u8 sum;
441 	int length, i;
442 
443 	printk(KERN_INFO "PnPBIOS: Scanning system for PnP BIOS support...\n");
444 
445 	/*
446 	 * Search the defined area (0xf0000-0xffff0) for a valid PnP BIOS
447 	 * structure and, if one is found, sets up the selectors and
448 	 * entry points
449 	 */
450 	for (check = (union pnp_bios_install_struct *)__va(0xf0000);
451 	     check < (union pnp_bios_install_struct *)__va(0xffff0);
452 	     check = (void *)check + 16) {
453 		if (check->fields.signature != PNP_SIGNATURE)
454 			continue;
455 		printk(KERN_INFO
456 		       "PnPBIOS: Found PnP BIOS installation structure at 0x%p\n",
457 		       check);
458 		length = check->fields.length;
459 		if (!length) {
460 			printk(KERN_ERR
461 			       "PnPBIOS: installation structure is invalid, skipping\n");
462 			continue;
463 		}
464 		for (sum = 0, i = 0; i < length; i++)
465 			sum += check->chars[i];
466 		if (sum) {
467 			printk(KERN_ERR
468 			       "PnPBIOS: installation structure is corrupted, skipping\n");
469 			continue;
470 		}
471 		if (check->fields.version < 0x10) {
472 			printk(KERN_WARNING
473 			       "PnPBIOS: PnP BIOS version %d.%d is not supported\n",
474 			       check->fields.version >> 4,
475 			       check->fields.version & 15);
476 			continue;
477 		}
478 		printk(KERN_INFO
479 		       "PnPBIOS: PnP BIOS version %d.%d, entry 0x%x:0x%x, dseg 0x%x\n",
480 		       check->fields.version >> 4, check->fields.version & 15,
481 		       check->fields.pm16cseg, check->fields.pm16offset,
482 		       check->fields.pm16dseg);
483 		pnp_bios_install = check;
484 		return 1;
485 	}
486 
487 	printk(KERN_INFO "PnPBIOS: PnP BIOS support was not detected.\n");
488 	return 0;
489 }
490 
491 static int __init exploding_pnp_bios(const struct dmi_system_id *d)
492 {
493 	printk(KERN_WARNING "%s detected. Disabling PnPBIOS\n", d->ident);
494 	return 0;
495 }
496 
497 static struct dmi_system_id pnpbios_dmi_table[] __initdata = {
498 	{			/* PnPBIOS GPF on boot */
499 	 .callback = exploding_pnp_bios,
500 	 .ident = "Higraded P14H",
501 	 .matches = {
502 		     DMI_MATCH(DMI_BIOS_VENDOR, "American Megatrends Inc."),
503 		     DMI_MATCH(DMI_BIOS_VERSION, "07.00T"),
504 		     DMI_MATCH(DMI_SYS_VENDOR, "Higraded"),
505 		     DMI_MATCH(DMI_PRODUCT_NAME, "P14H"),
506 		     },
507 	 },
508 	{			/* PnPBIOS GPF on boot */
509 	 .callback = exploding_pnp_bios,
510 	 .ident = "ASUS P4P800",
511 	 .matches = {
512 		     DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer Inc."),
513 		     DMI_MATCH(DMI_BOARD_NAME, "P4P800"),
514 		     },
515 	 },
516 	{}
517 };
518 
519 static int __init pnpbios_init(void)
520 {
521 	int ret;
522 
523 	if (pnpbios_disabled || dmi_check_system(pnpbios_dmi_table) ||
524 	    paravirt_enabled()) {
525 		printk(KERN_INFO "PnPBIOS: Disabled\n");
526 		return -ENODEV;
527 	}
528 #ifdef CONFIG_PNPACPI
529 	if (!acpi_disabled && !pnpacpi_disabled) {
530 		pnpbios_disabled = 1;
531 		printk(KERN_INFO "PnPBIOS: Disabled by ACPI PNP\n");
532 		return -ENODEV;
533 	}
534 #endif				/* CONFIG_ACPI */
535 
536 	/* scan the system for pnpbios support */
537 	if (!pnpbios_probe_system())
538 		return -ENODEV;
539 
540 	/* make preparations for bios calls */
541 	pnpbios_calls_init(pnp_bios_install);
542 
543 	/* read the node info */
544 	ret = pnp_bios_dev_node_info(&node_info);
545 	if (ret) {
546 		printk(KERN_ERR
547 		       "PnPBIOS: Unable to get node info.  Aborting.\n");
548 		return ret;
549 	}
550 
551 	/* register with the pnp layer */
552 	ret = pnp_register_protocol(&pnpbios_protocol);
553 	if (ret) {
554 		printk(KERN_ERR
555 		       "PnPBIOS: Unable to register driver.  Aborting.\n");
556 		return ret;
557 	}
558 
559 	/* start the proc interface */
560 	ret = pnpbios_proc_init();
561 	if (ret)
562 		printk(KERN_ERR "PnPBIOS: Failed to create proc interface.\n");
563 
564 	/* scan for pnpbios devices */
565 	build_devlist();
566 
567 	pnp_platform_devices = 1;
568 	return 0;
569 }
570 
571 fs_initcall(pnpbios_init);
572 
573 static int __init pnpbios_thread_init(void)
574 {
575 	struct task_struct *task;
576 
577 	if (pnpbios_disabled)
578 		return 0;
579 
580 	init_completion(&unload_sem);
581 	task = kthread_run(pnp_dock_thread, NULL, "kpnpbiosd");
582 	if (IS_ERR(task))
583 		return PTR_ERR(task);
584 
585 	return 0;
586 }
587 
588 /* Start the kernel thread later: */
589 module_init(pnpbios_thread_init);
590 
591 EXPORT_SYMBOL(pnpbios_protocol);
592