xref: /openbmc/linux/drivers/pnp/pnpbios/core.c (revision c21b37f6)
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  * 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 /*
90  *
91  * DOCKING FUNCTIONS
92  *
93  */
94 
95 #ifdef CONFIG_HOTPLUG
96 
97 static int unloading = 0;
98 static struct completion unload_sem;
99 
100 /*
101  * (Much of this belongs in a shared routine somewhere)
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 	if (!(envp = kcalloc(20, sizeof(char *), GFP_KERNEL)))
111 		return -ENOMEM;
112 	if (!(buf = kzalloc(256, GFP_KERNEL))) {
113 		kfree(envp);
114 		return -ENOMEM;
115 	}
116 
117 	/* FIXME: if there are actual users of this, it should be
118 	 * integrated into the driver core and use the usual infrastructure
119 	 * like sysfs and uevents
120 	 */
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, UMH_WAIT_EXEC);
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 
162 	set_freezable();
163 	while (!unloading) {
164 		int status;
165 
166 		/*
167 		 * Poll every 2 seconds
168 		 */
169 		msleep_interruptible(2000);
170 
171 		if (try_to_freeze())
172 			continue;
173 
174 		status = pnp_bios_dock_station_info(&now);
175 
176 		switch (status) {
177 			/*
178 			 * No dock to manage
179 			 */
180 		case PNP_FUNCTION_NOT_SUPPORTED:
181 			complete_and_exit(&unload_sem, 0);
182 		case PNP_SYSTEM_NOT_DOCKED:
183 			d = 0;
184 			break;
185 		case PNP_SUCCESS:
186 			d = 1;
187 			break;
188 		default:
189 			pnpbios_print_status("pnp_dock_thread", status);
190 			continue;
191 		}
192 		if (d != docked) {
193 			if (pnp_dock_event(d, &now) == 0) {
194 				docked = d;
195 #if 0
196 				printk(KERN_INFO
197 				       "PnPBIOS: Docking station %stached\n",
198 				       docked ? "at" : "de");
199 #endif
200 			}
201 		}
202 	}
203 	complete_and_exit(&unload_sem, 0);
204 }
205 
206 #endif				/* CONFIG_HOTPLUG */
207 
208 static int pnpbios_get_resources(struct pnp_dev *dev,
209 				 struct pnp_resource_table *res)
210 {
211 	u8 nodenum = dev->number;
212 	struct pnp_bios_node *node;
213 
214 	if (!pnpbios_is_dynamic(dev))
215 		return -EPERM;
216 
217 	node = kzalloc(node_info.max_node_size, GFP_KERNEL);
218 	if (!node)
219 		return -1;
220 	if (pnp_bios_get_dev_node(&nodenum, (char)PNPMODE_DYNAMIC, node)) {
221 		kfree(node);
222 		return -ENODEV;
223 	}
224 	pnpbios_read_resources_from_node(res, node);
225 	dev->active = pnp_is_active(dev);
226 	kfree(node);
227 	return 0;
228 }
229 
230 static int pnpbios_set_resources(struct pnp_dev *dev,
231 				 struct pnp_resource_table *res)
232 {
233 	u8 nodenum = dev->number;
234 	struct pnp_bios_node *node;
235 	int ret;
236 
237 	if (!pnpbios_is_dynamic(dev))
238 		return -EPERM;
239 
240 	node = kzalloc(node_info.max_node_size, GFP_KERNEL);
241 	if (!node)
242 		return -1;
243 	if (pnp_bios_get_dev_node(&nodenum, (char)PNPMODE_DYNAMIC, node)) {
244 		kfree(node);
245 		return -ENODEV;
246 	}
247 	if (pnpbios_write_resources_to_node(res, node) < 0) {
248 		kfree(node);
249 		return -1;
250 	}
251 	ret = pnp_bios_set_dev_node(node->handle, (char)PNPMODE_DYNAMIC, node);
252 	kfree(node);
253 	if (ret > 0)
254 		ret = -1;
255 	return ret;
256 }
257 
258 static void pnpbios_zero_data_stream(struct pnp_bios_node *node)
259 {
260 	unsigned char *p = (char *)node->data;
261 	unsigned char *end = (char *)(node->data + node->size);
262 	unsigned int len;
263 	int i;
264 
265 	while ((char *)p < (char *)end) {
266 		if (p[0] & 0x80) {	/* large tag */
267 			len = (p[2] << 8) | p[1];
268 			p += 3;
269 		} else {
270 			if (((p[0] >> 3) & 0x0f) == 0x0f)
271 				return;
272 			len = p[0] & 0x07;
273 			p += 1;
274 		}
275 		for (i = 0; i < len; i++)
276 			p[i] = 0;
277 		p += len;
278 	}
279 	printk(KERN_ERR
280 	       "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 	if (dev->flags & PNPBIOS_NO_DISABLE || !pnpbios_is_dynamic(dev))
290 		return -EPERM;
291 
292 	node = kzalloc(node_info.max_node_size, GFP_KERNEL);
293 	if (!node)
294 		return -ENOMEM;
295 
296 	if (pnp_bios_get_dev_node(&nodenum, (char)PNPMODE_DYNAMIC, node)) {
297 		kfree(node);
298 		return -ENODEV;
299 	}
300 	pnpbios_zero_data_stream(node);
301 
302 	ret = pnp_bios_set_dev_node(dev->number, (char)PNPMODE_DYNAMIC, node);
303 	kfree(node);
304 	if (ret > 0)
305 		ret = -1;
306 	return ret;
307 }
308 
309 /* PnP Layer support */
310 
311 struct pnp_protocol pnpbios_protocol = {
312 	.name = "Plug and Play BIOS",
313 	.get = pnpbios_get_resources,
314 	.set = pnpbios_set_resources,
315 	.disable = pnpbios_disable_resources,
316 };
317 
318 static int insert_device(struct pnp_dev *dev, struct pnp_bios_node *node)
319 {
320 	struct list_head *pos;
321 	struct pnp_dev *pnp_dev;
322 	struct pnp_id *dev_id;
323 	char id[8];
324 
325 	/* check if the device is already added */
326 	dev->number = node->handle;
327 	list_for_each(pos, &pnpbios_protocol.devices) {
328 		pnp_dev = list_entry(pos, struct pnp_dev, protocol_list);
329 		if (dev->number == pnp_dev->number)
330 			return -1;
331 	}
332 
333 	/* set the initial values for the PnP device */
334 	dev_id = kzalloc(sizeof(struct pnp_id), GFP_KERNEL);
335 	if (!dev_id)
336 		return -1;
337 	pnpid32_to_pnpid(node->eisa_id, id);
338 	memcpy(dev_id->id, id, 7);
339 	pnp_add_id(dev_id, dev);
340 	pnpbios_parse_data_stream(dev, node);
341 	dev->active = pnp_is_active(dev);
342 	dev->flags = node->flags;
343 	if (!(dev->flags & PNPBIOS_NO_CONFIG))
344 		dev->capabilities |= PNP_CONFIGURABLE;
345 	if (!(dev->flags & PNPBIOS_NO_DISABLE) && pnpbios_is_dynamic(dev))
346 		dev->capabilities |= PNP_DISABLE;
347 	dev->capabilities |= PNP_READ;
348 	if (pnpbios_is_dynamic(dev))
349 		dev->capabilities |= PNP_WRITE;
350 	if (dev->flags & PNPBIOS_REMOVABLE)
351 		dev->capabilities |= PNP_REMOVABLE;
352 	dev->protocol = &pnpbios_protocol;
353 
354 	/* clear out the damaged flags */
355 	if (!dev->active)
356 		pnp_init_resource_table(&dev->res);
357 
358 	pnp_add_device(dev);
359 	pnpbios_interface_attach_device(node);
360 
361 	return 0;
362 }
363 
364 static void __init build_devlist(void)
365 {
366 	u8 nodenum;
367 	unsigned int nodes_got = 0;
368 	unsigned int devs = 0;
369 	struct pnp_bios_node *node;
370 	struct pnp_dev *dev;
371 
372 	node = kzalloc(node_info.max_node_size, GFP_KERNEL);
373 	if (!node)
374 		return;
375 
376 	for (nodenum = 0; nodenum < 0xff;) {
377 		u8 thisnodenum = nodenum;
378 		/* eventually we will want to use PNPMODE_STATIC here but for now
379 		 * dynamic will help us catch buggy bioses to add to the blacklist.
380 		 */
381 		if (!pnpbios_dont_use_current_config) {
382 			if (pnp_bios_get_dev_node
383 			    (&nodenum, (char)PNPMODE_DYNAMIC, node))
384 				break;
385 		} else {
386 			if (pnp_bios_get_dev_node
387 			    (&nodenum, (char)PNPMODE_STATIC, node))
388 				break;
389 		}
390 		nodes_got++;
391 		dev = kzalloc(sizeof(struct pnp_dev), GFP_KERNEL);
392 		if (!dev)
393 			break;
394 		if (insert_device(dev, node) < 0)
395 			kfree(dev);
396 		else
397 			devs++;
398 		if (nodenum <= thisnodenum) {
399 			printk(KERN_ERR
400 			       "PnPBIOS: build_devlist: Node number 0x%x is out of sequence following node 0x%x. Aborting.\n",
401 			       (unsigned int)nodenum,
402 			       (unsigned int)thisnodenum);
403 			break;
404 		}
405 	}
406 	kfree(node);
407 
408 	printk(KERN_INFO
409 	       "PnPBIOS: %i node%s reported by PnP BIOS; %i recorded by driver\n",
410 	       nodes_got, nodes_got != 1 ? "s" : "", devs);
411 }
412 
413 /*
414  *
415  * INIT AND EXIT
416  *
417  */
418 
419 static int pnpbios_disabled;
420 int pnpbios_dont_use_current_config;
421 
422 #ifndef MODULE
423 static int __init pnpbios_setup(char *str)
424 {
425 	int invert;
426 
427 	while ((str != NULL) && (*str != '\0')) {
428 		if (strncmp(str, "off", 3) == 0)
429 			pnpbios_disabled = 1;
430 		if (strncmp(str, "on", 2) == 0)
431 			pnpbios_disabled = 0;
432 		invert = (strncmp(str, "no-", 3) == 0);
433 		if (invert)
434 			str += 3;
435 		if (strncmp(str, "curr", 4) == 0)
436 			pnpbios_dont_use_current_config = invert;
437 		str = strchr(str, ',');
438 		if (str != NULL)
439 			str += strspn(str, ", \t");
440 	}
441 
442 	return 1;
443 }
444 
445 __setup("pnpbios=", pnpbios_setup);
446 #endif
447 
448 /* PnP BIOS signature: "$PnP" */
449 #define PNP_SIGNATURE   (('$' << 0) + ('P' << 8) + ('n' << 16) + ('P' << 24))
450 
451 static int __init pnpbios_probe_system(void)
452 {
453 	union pnp_bios_install_struct *check;
454 	u8 sum;
455 	int length, i;
456 
457 	printk(KERN_INFO "PnPBIOS: Scanning system for PnP BIOS support...\n");
458 
459 	/*
460 	 * Search the defined area (0xf0000-0xffff0) for a valid PnP BIOS
461 	 * structure and, if one is found, sets up the selectors and
462 	 * entry points
463 	 */
464 	for (check = (union pnp_bios_install_struct *)__va(0xf0000);
465 	     check < (union pnp_bios_install_struct *)__va(0xffff0);
466 	     check = (void *)check + 16) {
467 		if (check->fields.signature != PNP_SIGNATURE)
468 			continue;
469 		printk(KERN_INFO
470 		       "PnPBIOS: Found PnP BIOS installation structure at 0x%p\n",
471 		       check);
472 		length = check->fields.length;
473 		if (!length) {
474 			printk(KERN_ERR
475 			       "PnPBIOS: installation structure is invalid, skipping\n");
476 			continue;
477 		}
478 		for (sum = 0, i = 0; i < length; i++)
479 			sum += check->chars[i];
480 		if (sum) {
481 			printk(KERN_ERR
482 			       "PnPBIOS: installation structure is corrupted, skipping\n");
483 			continue;
484 		}
485 		if (check->fields.version < 0x10) {
486 			printk(KERN_WARNING
487 			       "PnPBIOS: PnP BIOS version %d.%d is not supported\n",
488 			       check->fields.version >> 4,
489 			       check->fields.version & 15);
490 			continue;
491 		}
492 		printk(KERN_INFO
493 		       "PnPBIOS: PnP BIOS version %d.%d, entry 0x%x:0x%x, dseg 0x%x\n",
494 		       check->fields.version >> 4, check->fields.version & 15,
495 		       check->fields.pm16cseg, check->fields.pm16offset,
496 		       check->fields.pm16dseg);
497 		pnp_bios_install = check;
498 		return 1;
499 	}
500 
501 	printk(KERN_INFO "PnPBIOS: PnP BIOS support was not detected.\n");
502 	return 0;
503 }
504 
505 static int __init exploding_pnp_bios(struct dmi_system_id *d)
506 {
507 	printk(KERN_WARNING "%s detected. Disabling PnPBIOS\n", d->ident);
508 	return 0;
509 }
510 
511 static struct dmi_system_id pnpbios_dmi_table[] __initdata = {
512 	{			/* PnPBIOS GPF on boot */
513 	 .callback = exploding_pnp_bios,
514 	 .ident = "Higraded P14H",
515 	 .matches = {
516 		     DMI_MATCH(DMI_BIOS_VENDOR, "American Megatrends Inc."),
517 		     DMI_MATCH(DMI_BIOS_VERSION, "07.00T"),
518 		     DMI_MATCH(DMI_SYS_VENDOR, "Higraded"),
519 		     DMI_MATCH(DMI_PRODUCT_NAME, "P14H"),
520 		     },
521 	 },
522 	{			/* PnPBIOS GPF on boot */
523 	 .callback = exploding_pnp_bios,
524 	 .ident = "ASUS P4P800",
525 	 .matches = {
526 		     DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer Inc."),
527 		     DMI_MATCH(DMI_BOARD_NAME, "P4P800"),
528 		     },
529 	 },
530 	{}
531 };
532 
533 static int __init pnpbios_init(void)
534 {
535 	int ret;
536 
537 #if defined(CONFIG_PPC_MERGE)
538 	if (check_legacy_ioport(PNPBIOS_BASE))
539 		return -ENODEV;
540 #endif
541 	if (pnpbios_disabled || dmi_check_system(pnpbios_dmi_table) ||
542 	    paravirt_enabled()) {
543 		printk(KERN_INFO "PnPBIOS: Disabled\n");
544 		return -ENODEV;
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
565 		       "PnPBIOS: Unable to get node info.  Aborting.\n");
566 		return ret;
567 	}
568 
569 	/* register with the pnp layer */
570 	ret = pnp_register_protocol(&pnpbios_protocol);
571 	if (ret) {
572 		printk(KERN_ERR
573 		       "PnPBIOS: Unable to register driver.  Aborting.\n");
574 		return ret;
575 	}
576 
577 	/* start the proc interface */
578 	ret = pnpbios_proc_init();
579 	if (ret)
580 		printk(KERN_ERR "PnPBIOS: Failed to create proc interface.\n");
581 
582 	/* scan for pnpbios devices */
583 	build_devlist();
584 
585 	pnp_platform_devices = 1;
586 	return 0;
587 }
588 
589 subsys_initcall(pnpbios_init);
590 
591 static int __init pnpbios_thread_init(void)
592 {
593 	struct task_struct *task;
594 #if defined(CONFIG_PPC_MERGE)
595 	if (check_legacy_ioport(PNPBIOS_BASE))
596 		return 0;
597 #endif
598 	if (pnpbios_disabled)
599 		return 0;
600 #ifdef CONFIG_HOTPLUG
601 	init_completion(&unload_sem);
602 	task = kthread_run(pnp_dock_thread, NULL, "kpnpbiosd");
603 	if (!IS_ERR(task))
604 		unloading = 0;
605 #endif
606 	return 0;
607 }
608 
609 #ifndef MODULE
610 
611 /* init/main.c calls pnpbios_init early */
612 
613 /* Start the kernel thread later: */
614 module_init(pnpbios_thread_init);
615 
616 #else
617 
618 /*
619  * N.B.: Building pnpbios as a module hasn't been fully implemented
620  */
621 
622 MODULE_LICENSE("GPL");
623 
624 static int __init pnpbios_init_all(void)
625 {
626 	int r;
627 
628 	r = pnpbios_init();
629 	if (r)
630 		return r;
631 	r = pnpbios_thread_init();
632 	if (r)
633 		return r;
634 	return 0;
635 }
636 
637 static void __exit pnpbios_exit(void)
638 {
639 #ifdef CONFIG_HOTPLUG
640 	unloading = 1;
641 	wait_for_completion(&unload_sem);
642 #endif
643 	pnpbios_proc_exit();
644 	/* We ought to free resources here */
645 	return;
646 }
647 
648 module_init(pnpbios_init_all);
649 module_exit(pnpbios_exit);
650 
651 #endif
652 
653 EXPORT_SYMBOL(pnpbios_protocol);
654