xref: /openbmc/linux/drivers/pnp/pnpbios/core.c (revision 64c70b1c)
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 #include <linux/kthread.h>
66 
67 #include <asm/page.h>
68 #include <asm/desc.h>
69 #include <asm/system.h>
70 #include <asm/byteorder.h>
71 
72 #include "pnpbios.h"
73 
74 
75 /*
76  *
77  * PnP BIOS INTERFACE
78  *
79  */
80 
81 static union pnp_bios_install_struct * pnp_bios_install = NULL;
82 
83 int pnp_bios_present(void)
84 {
85 	return (pnp_bios_install != NULL);
86 }
87 
88 struct pnp_dev_node_info node_info;
89 
90 /*
91  *
92  * DOCKING FUNCTIONS
93  *
94  */
95 
96 #ifdef CONFIG_HOTPLUG
97 
98 static int unloading = 0;
99 static struct completion unload_sem;
100 
101 /*
102  * (Much of this belongs in a shared routine somewhere)
103  */
104 
105 static int pnp_dock_event(int dock, struct pnp_docking_station_info *info)
106 {
107 	char *argv [3], **envp, *buf, *scratch;
108 	int i = 0, value;
109 
110 	if (!current->fs->root) {
111 		return -EAGAIN;
112 	}
113 	if (!(envp = kcalloc(20, sizeof (char *), GFP_KERNEL))) {
114 		return -ENOMEM;
115 	}
116 	if (!(buf = kzalloc(256, GFP_KERNEL))) {
117 		kfree (envp);
118 		return -ENOMEM;
119 	}
120 
121 	/* FIXME: if there are actual users of this, it should be integrated into
122 	 * the driver core and use the usual infrastructure like sysfs and uevents */
123 	argv [0] = "/sbin/pnpbios";
124 	argv [1] = "dock";
125 	argv [2] = NULL;
126 
127 	/* minimal command environment */
128 	envp [i++] = "HOME=/";
129 	envp [i++] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin";
130 
131 #ifdef	DEBUG
132 	/* hint that policy agent should enter no-stdout debug mode */
133 	envp [i++] = "DEBUG=kernel";
134 #endif
135 	/* extensible set of named bus-specific parameters,
136 	 * supporting multiple driver selection algorithms.
137 	 */
138 	scratch = buf;
139 
140 	/* action:  add, remove */
141 	envp [i++] = scratch;
142 	scratch += sprintf (scratch, "ACTION=%s", dock?"add":"remove") + 1;
143 
144 	/* Report the ident for the dock */
145 	envp [i++] = scratch;
146 	scratch += sprintf (scratch, "DOCK=%x/%x/%x",
147 		info->location_id, info->serial, info->capabilities);
148 	envp[i] = NULL;
149 
150 	value = call_usermodehelper (argv [0], argv, envp, 0);
151 	kfree (buf);
152 	kfree (envp);
153 	return 0;
154 }
155 
156 /*
157  * Poll the PnP docking at regular intervals
158  */
159 static int pnp_dock_thread(void * unused)
160 {
161 	static struct pnp_docking_station_info now;
162 	int docked = -1, d = 0;
163 	while (!unloading)
164 	{
165 		int status;
166 
167 		/*
168 		 * Poll every 2 seconds
169 		 */
170 		msleep_interruptible(2000);
171 
172 		if (try_to_freeze())
173 			continue;
174 
175 		status = pnp_bios_dock_station_info(&now);
176 
177 		switch(status)
178 		{
179 			/*
180 			 * No dock to manage
181 			 */
182 			case PNP_FUNCTION_NOT_SUPPORTED:
183 				complete_and_exit(&unload_sem, 0);
184 			case PNP_SYSTEM_NOT_DOCKED:
185 				d = 0;
186 				break;
187 			case PNP_SUCCESS:
188 				d = 1;
189 				break;
190 			default:
191 				pnpbios_print_status( "pnp_dock_thread", status );
192 				continue;
193 		}
194 		if(d != docked)
195 		{
196 			if(pnp_dock_event(d, &now)==0)
197 			{
198 				docked = d;
199 #if 0
200 				printk(KERN_INFO "PnPBIOS: Docking station %stached\n", docked?"at":"de");
201 #endif
202 			}
203 		}
204 	}
205 	complete_and_exit(&unload_sem, 0);
206 }
207 
208 #endif   /* CONFIG_HOTPLUG */
209 
210 static int pnpbios_get_resources(struct pnp_dev * dev, struct pnp_resource_table * res)
211 {
212 	u8 nodenum = dev->number;
213 	struct pnp_bios_node * node;
214 
215 	/* just in case */
216 	if(!pnpbios_is_dynamic(dev))
217 		return -EPERM;
218 
219 	node = kzalloc(node_info.max_node_size, GFP_KERNEL);
220 	if (!node)
221 		return -1;
222 	if (pnp_bios_get_dev_node(&nodenum, (char )PNPMODE_DYNAMIC, node)) {
223 		kfree(node);
224 		return -ENODEV;
225 	}
226 	pnpbios_read_resources_from_node(res, node);
227 	dev->active = pnp_is_active(dev);
228 	kfree(node);
229 	return 0;
230 }
231 
232 static int pnpbios_set_resources(struct pnp_dev * dev, struct pnp_resource_table * res)
233 {
234 	u8 nodenum = dev->number;
235 	struct pnp_bios_node * node;
236 	int ret;
237 
238 	/* just in case */
239 	if (!pnpbios_is_dynamic(dev))
240 		return -EPERM;
241 
242 	node = kzalloc(node_info.max_node_size, GFP_KERNEL);
243 	if (!node)
244 		return -1;
245 	if (pnp_bios_get_dev_node(&nodenum, (char )PNPMODE_DYNAMIC, node)) {
246 		kfree(node);
247 		return -ENODEV;
248 	}
249 	if(pnpbios_write_resources_to_node(res, node)<0) {
250 		kfree(node);
251 		return -1;
252 	}
253 	ret = pnp_bios_set_dev_node(node->handle, (char)PNPMODE_DYNAMIC, node);
254 	kfree(node);
255 	if (ret > 0)
256 		ret = -1;
257 	return ret;
258 }
259 
260 static void pnpbios_zero_data_stream(struct pnp_bios_node * node)
261 {
262 	unsigned char * p = (char *)node->data;
263 	unsigned char * end = (char *)(node->data + node->size);
264 	unsigned int len;
265 	int i;
266 	while ((char *)p < (char *)end) {
267 		if(p[0] & 0x80) { /* large tag */
268 			len = (p[2] << 8) | p[1];
269 			p += 3;
270 		} else {
271 			if (((p[0]>>3) & 0x0f) == 0x0f)
272 				return;
273 			len = p[0] & 0x07;
274 			p += 1;
275 		}
276 		for (i = 0; i < len; i++)
277 			p[i] = 0;
278 		p += len;
279 	}
280 	printk(KERN_ERR "PnPBIOS: Resource structure did not contain an end tag.\n");
281 }
282 
283 static int pnpbios_disable_resources(struct pnp_dev *dev)
284 {
285 	struct pnp_bios_node * node;
286 	u8 nodenum = dev->number;
287 	int ret;
288 
289 	/* just in case */
290 	if(dev->flags & PNPBIOS_NO_DISABLE || !pnpbios_is_dynamic(dev))
291 		return -EPERM;
292 
293 	node = kzalloc(node_info.max_node_size, GFP_KERNEL);
294 	if (!node)
295 		return -ENOMEM;
296 
297 	if (pnp_bios_get_dev_node(&nodenum, (char )PNPMODE_DYNAMIC, node)) {
298 		kfree(node);
299 		return -ENODEV;
300 	}
301 	pnpbios_zero_data_stream(node);
302 
303 	ret = pnp_bios_set_dev_node(dev->number, (char)PNPMODE_DYNAMIC, node);
304 	kfree(node);
305 	if (ret > 0)
306 		ret = -1;
307 	return ret;
308 }
309 
310 /* PnP Layer support */
311 
312 struct pnp_protocol pnpbios_protocol = {
313 	.name	= "Plug and Play BIOS",
314 	.get	= pnpbios_get_resources,
315 	.set	= pnpbios_set_resources,
316 	.disable = pnpbios_disable_resources,
317 };
318 
319 static int insert_device(struct pnp_dev *dev, struct pnp_bios_node * node)
320 {
321 	struct list_head * pos;
322 	struct pnp_dev * pnp_dev;
323 	struct pnp_id *dev_id;
324 	char id[8];
325 
326 	/* check if the device is already added */
327 	dev->number = node->handle;
328 	list_for_each (pos, &pnpbios_protocol.devices){
329 		pnp_dev = list_entry(pos, struct pnp_dev, protocol_list);
330 		if (dev->number == pnp_dev->number)
331 			return -1;
332 	}
333 
334 	/* set the initial values for the PnP device */
335 	dev_id = kzalloc(sizeof(struct pnp_id), GFP_KERNEL);
336 	if (!dev_id)
337 		return -1;
338 	pnpid32_to_pnpid(node->eisa_id,id);
339 	memcpy(dev_id->id,id,7);
340 	pnp_add_id(dev_id, dev);
341 	pnpbios_parse_data_stream(dev, node);
342 	dev->active = pnp_is_active(dev);
343 	dev->flags = node->flags;
344 	if (!(dev->flags & PNPBIOS_NO_CONFIG))
345 		dev->capabilities |= PNP_CONFIGURABLE;
346 	if (!(dev->flags & PNPBIOS_NO_DISABLE) && pnpbios_is_dynamic(dev))
347 		dev->capabilities |= PNP_DISABLE;
348 	dev->capabilities |= PNP_READ;
349 	if (pnpbios_is_dynamic(dev))
350 		dev->capabilities |= PNP_WRITE;
351 	if (dev->flags & PNPBIOS_REMOVABLE)
352 		dev->capabilities |= PNP_REMOVABLE;
353 	dev->protocol = &pnpbios_protocol;
354 
355 	/* clear out the damaged flags */
356 	if (!dev->active)
357 		pnp_init_resource_table(&dev->res);
358 
359 	pnp_add_device(dev);
360 	pnpbios_interface_attach_device(node);
361 
362 	return 0;
363 }
364 
365 static void __init build_devlist(void)
366 {
367 	u8 nodenum;
368 	unsigned int nodes_got = 0;
369 	unsigned int devs = 0;
370 	struct pnp_bios_node *node;
371 	struct pnp_dev *dev;
372 
373 	node = kzalloc(node_info.max_node_size, GFP_KERNEL);
374 	if (!node)
375 		return;
376 
377 	for(nodenum=0; nodenum<0xff; ) {
378 		u8 thisnodenum = nodenum;
379 		/* eventually we will want to use PNPMODE_STATIC here but for now
380 		 * dynamic will help us catch buggy bioses to add to the blacklist.
381 		 */
382 		if (!pnpbios_dont_use_current_config) {
383 			if (pnp_bios_get_dev_node(&nodenum, (char )PNPMODE_DYNAMIC, node))
384 				break;
385 		} else {
386 			if (pnp_bios_get_dev_node(&nodenum, (char )PNPMODE_STATIC, node))
387 				break;
388 		}
389 		nodes_got++;
390 		dev =  kzalloc(sizeof (struct pnp_dev), GFP_KERNEL);
391 		if (!dev)
392 			break;
393 		if(insert_device(dev,node)<0)
394 			kfree(dev);
395 		else
396 			devs++;
397 		if (nodenum <= thisnodenum) {
398 			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);
399 			break;
400 		}
401 	}
402 	kfree(node);
403 
404 	printk(KERN_INFO "PnPBIOS: %i node%s reported by PnP BIOS; %i recorded by driver\n",
405 		nodes_got, nodes_got != 1 ? "s" : "", devs);
406 }
407 
408 /*
409  *
410  * INIT AND EXIT
411  *
412  */
413 
414 static int pnpbios_disabled; /* = 0 */
415 int pnpbios_dont_use_current_config; /* = 0 */
416 
417 #ifndef MODULE
418 static int __init pnpbios_setup(char *str)
419 {
420 	int invert;
421 
422 	while ((str != NULL) && (*str != '\0')) {
423 		if (strncmp(str, "off", 3) == 0)
424 			pnpbios_disabled=1;
425 		if (strncmp(str, "on", 2) == 0)
426 			pnpbios_disabled=0;
427 		invert = (strncmp(str, "no-", 3) == 0);
428 		if (invert)
429 			str += 3;
430 		if (strncmp(str, "curr", 4) == 0)
431 			pnpbios_dont_use_current_config = invert;
432 		str = strchr(str, ',');
433 		if (str != NULL)
434 			str += strspn(str, ", \t");
435 	}
436 
437 	return 1;
438 }
439 
440 __setup("pnpbios=", pnpbios_setup);
441 #endif
442 
443 /* PnP BIOS signature: "$PnP" */
444 #define PNP_SIGNATURE   (('$' << 0) + ('P' << 8) + ('n' << 16) + ('P' << 24))
445 
446 static int __init pnpbios_probe_system(void)
447 {
448 	union pnp_bios_install_struct *check;
449 	u8 sum;
450 	int length, i;
451 
452 	printk(KERN_INFO "PnPBIOS: Scanning system for PnP BIOS support...\n");
453 
454 	/*
455  	 * Search the defined area (0xf0000-0xffff0) for a valid PnP BIOS
456 	 * structure and, if one is found, sets up the selectors and
457 	 * entry points
458 	 */
459 	for (check = (union pnp_bios_install_struct *) __va(0xf0000);
460 	     check < (union pnp_bios_install_struct *) __va(0xffff0);
461 	     check = (void *)check + 16) {
462 		if (check->fields.signature != PNP_SIGNATURE)
463 			continue;
464 		printk(KERN_INFO "PnPBIOS: Found PnP BIOS installation structure at 0x%p\n", check);
465 		length = check->fields.length;
466 		if (!length) {
467 			printk(KERN_ERR "PnPBIOS: installation structure is invalid, skipping\n");
468 			continue;
469 		}
470 		for (sum = 0, i = 0; i < length; i++)
471 			sum += check->chars[i];
472 		if (sum) {
473 			printk(KERN_ERR "PnPBIOS: installation structure is corrupted, skipping\n");
474 			continue;
475 		}
476 		if (check->fields.version < 0x10) {
477 			printk(KERN_WARNING "PnPBIOS: PnP BIOS version %d.%d is not supported\n",
478 			       check->fields.version >> 4,
479 			       check->fields.version & 15);
480 			continue;
481 		}
482 		printk(KERN_INFO "PnPBIOS: PnP BIOS version %d.%d, entry 0x%x:0x%x, dseg 0x%x\n",
483                        check->fields.version >> 4, check->fields.version & 15,
484 		       check->fields.pm16cseg, check->fields.pm16offset,
485 		       check->fields.pm16dseg);
486 		pnp_bios_install = check;
487 		return 1;
488 	}
489 
490 	printk(KERN_INFO "PnPBIOS: PnP BIOS support was not detected.\n");
491 	return 0;
492 }
493 
494 static int __init exploding_pnp_bios(struct dmi_system_id *d)
495 {
496 	printk(KERN_WARNING "%s detected. Disabling PnPBIOS\n", d->ident);
497 	return 0;
498 }
499 
500 static struct dmi_system_id pnpbios_dmi_table[] __initdata = {
501 	{	/* PnPBIOS GPF on boot */
502 		.callback = exploding_pnp_bios,
503 		.ident = "Higraded P14H",
504 		.matches = {
505 			DMI_MATCH(DMI_BIOS_VENDOR, "American Megatrends Inc."),
506 			DMI_MATCH(DMI_BIOS_VERSION, "07.00T"),
507 			DMI_MATCH(DMI_SYS_VENDOR, "Higraded"),
508 			DMI_MATCH(DMI_PRODUCT_NAME, "P14H"),
509 		},
510 	},
511 	{	/* PnPBIOS GPF on boot */
512 		.callback = exploding_pnp_bios,
513 		.ident = "ASUS P4P800",
514 		.matches = {
515 			DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer Inc."),
516 			DMI_MATCH(DMI_BOARD_NAME, "P4P800"),
517 		},
518 	},
519 	{ }
520 };
521 
522 static int __init pnpbios_init(void)
523 {
524 	int ret;
525 
526 #if defined(CONFIG_PPC_MERGE)
527 	if (check_legacy_ioport(PNPBIOS_BASE))
528 		return -ENODEV;
529 #endif
530 	if (pnpbios_disabled || dmi_check_system(pnpbios_dmi_table) ||
531 	    paravirt_enabled()) {
532 		printk(KERN_INFO "PnPBIOS: Disabled\n");
533 		return -ENODEV;
534 	}
535 
536 #ifdef CONFIG_PNPACPI
537 	if (!acpi_disabled && !pnpacpi_disabled) {
538 		pnpbios_disabled = 1;
539 		printk(KERN_INFO "PnPBIOS: Disabled by ACPI PNP\n");
540 		return -ENODEV;
541 	}
542 #endif /* CONFIG_ACPI */
543 
544 	/* scan the system for pnpbios support */
545 	if (!pnpbios_probe_system())
546 		return -ENODEV;
547 
548 	/* make preparations for bios calls */
549 	pnpbios_calls_init(pnp_bios_install);
550 
551 	/* read the node info */
552 	ret = pnp_bios_dev_node_info(&node_info);
553 	if (ret) {
554 		printk(KERN_ERR "PnPBIOS: Unable to get node info.  Aborting.\n");
555 		return ret;
556 	}
557 
558 	/* register with the pnp layer */
559 	ret = pnp_register_protocol(&pnpbios_protocol);
560 	if (ret) {
561 		printk(KERN_ERR "PnPBIOS: Unable to register driver.  Aborting.\n");
562 		return ret;
563 	}
564 
565 	/* start the proc interface */
566 	ret = pnpbios_proc_init();
567 	if (ret)
568 		printk(KERN_ERR "PnPBIOS: Failed to create proc interface.\n");
569 
570 	/* scan for pnpbios devices */
571 	build_devlist();
572 
573 	pnp_platform_devices = 1;
574 	return 0;
575 }
576 
577 subsys_initcall(pnpbios_init);
578 
579 static int __init pnpbios_thread_init(void)
580 {
581 	struct task_struct *task;
582 #if defined(CONFIG_PPC_MERGE)
583 	if (check_legacy_ioport(PNPBIOS_BASE))
584 		return 0;
585 #endif
586 	if (pnpbios_disabled)
587 		return 0;
588 #ifdef CONFIG_HOTPLUG
589 	init_completion(&unload_sem);
590 	task = kthread_run(pnp_dock_thread, NULL, "kpnpbiosd");
591 	if (!IS_ERR(task))
592 		unloading = 0;
593 #endif
594 	return 0;
595 }
596 
597 #ifndef MODULE
598 
599 /* init/main.c calls pnpbios_init early */
600 
601 /* Start the kernel thread later: */
602 module_init(pnpbios_thread_init);
603 
604 #else
605 
606 /*
607  * N.B.: Building pnpbios as a module hasn't been fully implemented
608  */
609 
610 MODULE_LICENSE("GPL");
611 
612 static int __init pnpbios_init_all(void)
613 {
614 	int r;
615 
616 	r = pnpbios_init();
617 	if (r)
618 		return r;
619 	r = pnpbios_thread_init();
620 	if (r)
621 		return r;
622 	return 0;
623 }
624 
625 static void __exit pnpbios_exit(void)
626 {
627 #ifdef CONFIG_HOTPLUG
628 	unloading = 1;
629 	wait_for_completion(&unload_sem);
630 #endif
631 	pnpbios_proc_exit();
632 	/* We ought to free resources here */
633 	return;
634 }
635 
636 module_init(pnpbios_init_all);
637 module_exit(pnpbios_exit);
638 
639 #endif
640 
641 EXPORT_SYMBOL(pnpbios_protocol);
642