core.c revision 9dd78466c956ac4b4f38e12032dc4249ccf57ad1
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
80static union pnp_bios_install_struct *pnp_bios_install = NULL;
81
82int pnp_bios_present(void)
83{
84	return (pnp_bios_install != NULL);
85}
86
87struct pnp_dev_node_info node_info;
88
89/*
90 *
91 * DOCKING FUNCTIONS
92 *
93 */
94
95#ifdef CONFIG_HOTPLUG
96
97static int unloading = 0;
98static struct completion unload_sem;
99
100/*
101 * (Much of this belongs in a shared routine somewhere)
102 */
103
104static int pnp_dock_event(int dock, struct pnp_docking_station_info *info)
105{
106	char *argv[3], **envp, *buf, *scratch;
107	int i = 0, value;
108
109	if (!current->fs->root) {
110		return -EAGAIN;
111	}
112	if (!(envp = kcalloc(20, sizeof(char *), GFP_KERNEL))) {
113		return -ENOMEM;
114	}
115	if (!(buf = kzalloc(256, GFP_KERNEL))) {
116		kfree(envp);
117		return -ENOMEM;
118	}
119
120	/* FIXME: if there are actual users of this, it should be integrated into
121	 * the driver core and use the usual infrastructure like sysfs and uevents */
122	argv[0] = "/sbin/pnpbios";
123	argv[1] = "dock";
124	argv[2] = NULL;
125
126	/* minimal command environment */
127	envp[i++] = "HOME=/";
128	envp[i++] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin";
129
130#ifdef	DEBUG
131	/* hint that policy agent should enter no-stdout debug mode */
132	envp[i++] = "DEBUG=kernel";
133#endif
134	/* extensible set of named bus-specific parameters,
135	 * supporting multiple driver selection algorithms.
136	 */
137	scratch = buf;
138
139	/* action:  add, remove */
140	envp[i++] = scratch;
141	scratch += sprintf(scratch, "ACTION=%s", dock ? "add" : "remove") + 1;
142
143	/* Report the ident for the dock */
144	envp[i++] = scratch;
145	scratch += sprintf(scratch, "DOCK=%x/%x/%x",
146			   info->location_id, info->serial, info->capabilities);
147	envp[i] = NULL;
148
149	value = call_usermodehelper(argv[0], argv, envp, UMH_WAIT_EXEC);
150	kfree(buf);
151	kfree(envp);
152	return 0;
153}
154
155/*
156 * Poll the PnP docking at regular intervals
157 */
158static int pnp_dock_thread(void *unused)
159{
160	static struct pnp_docking_station_info now;
161	int docked = -1, d = 0;
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
208static 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	/* just in case */
215	if (!pnpbios_is_dynamic(dev))
216		return -EPERM;
217
218	node = kzalloc(node_info.max_node_size, GFP_KERNEL);
219	if (!node)
220		return -1;
221	if (pnp_bios_get_dev_node(&nodenum, (char)PNPMODE_DYNAMIC, node)) {
222		kfree(node);
223		return -ENODEV;
224	}
225	pnpbios_read_resources_from_node(res, node);
226	dev->active = pnp_is_active(dev);
227	kfree(node);
228	return 0;
229}
230
231static int pnpbios_set_resources(struct pnp_dev *dev,
232				 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
260static 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
281	       "PnPBIOS: Resource structure did not contain an end tag.\n");
282}
283
284static int pnpbios_disable_resources(struct pnp_dev *dev)
285{
286	struct pnp_bios_node *node;
287	u8 nodenum = dev->number;
288	int ret;
289
290	/* just in case */
291	if (dev->flags & PNPBIOS_NO_DISABLE || !pnpbios_is_dynamic(dev))
292		return -EPERM;
293
294	node = kzalloc(node_info.max_node_size, GFP_KERNEL);
295	if (!node)
296		return -ENOMEM;
297
298	if (pnp_bios_get_dev_node(&nodenum, (char)PNPMODE_DYNAMIC, node)) {
299		kfree(node);
300		return -ENODEV;
301	}
302	pnpbios_zero_data_stream(node);
303
304	ret = pnp_bios_set_dev_node(dev->number, (char)PNPMODE_DYNAMIC, node);
305	kfree(node);
306	if (ret > 0)
307		ret = -1;
308	return ret;
309}
310
311/* PnP Layer support */
312
313struct pnp_protocol pnpbios_protocol = {
314	.name = "Plug and Play BIOS",
315	.get = pnpbios_get_resources,
316	.set = pnpbios_set_resources,
317	.disable = pnpbios_disable_resources,
318};
319
320static int insert_device(struct pnp_dev *dev, struct pnp_bios_node *node)
321{
322	struct list_head *pos;
323	struct pnp_dev *pnp_dev;
324	struct pnp_id *dev_id;
325	char id[8];
326
327	/* check if the device is already added */
328	dev->number = node->handle;
329	list_for_each(pos, &pnpbios_protocol.devices) {
330		pnp_dev = list_entry(pos, struct pnp_dev, protocol_list);
331		if (dev->number == pnp_dev->number)
332			return -1;
333	}
334
335	/* set the initial values for the PnP device */
336	dev_id = kzalloc(sizeof(struct pnp_id), GFP_KERNEL);
337	if (!dev_id)
338		return -1;
339	pnpid32_to_pnpid(node->eisa_id, id);
340	memcpy(dev_id->id, id, 7);
341	pnp_add_id(dev_id, dev);
342	pnpbios_parse_data_stream(dev, node);
343	dev->active = pnp_is_active(dev);
344	dev->flags = node->flags;
345	if (!(dev->flags & PNPBIOS_NO_CONFIG))
346		dev->capabilities |= PNP_CONFIGURABLE;
347	if (!(dev->flags & PNPBIOS_NO_DISABLE) && pnpbios_is_dynamic(dev))
348		dev->capabilities |= PNP_DISABLE;
349	dev->capabilities |= PNP_READ;
350	if (pnpbios_is_dynamic(dev))
351		dev->capabilities |= PNP_WRITE;
352	if (dev->flags & PNPBIOS_REMOVABLE)
353		dev->capabilities |= PNP_REMOVABLE;
354	dev->protocol = &pnpbios_protocol;
355
356	/* clear out the damaged flags */
357	if (!dev->active)
358		pnp_init_resource_table(&dev->res);
359
360	pnp_add_device(dev);
361	pnpbios_interface_attach_device(node);
362
363	return 0;
364}
365
366static void __init build_devlist(void)
367{
368	u8 nodenum;
369	unsigned int nodes_got = 0;
370	unsigned int devs = 0;
371	struct pnp_bios_node *node;
372	struct pnp_dev *dev;
373
374	node = kzalloc(node_info.max_node_size, GFP_KERNEL);
375	if (!node)
376		return;
377
378	for (nodenum = 0; nodenum < 0xff;) {
379		u8 thisnodenum = nodenum;
380		/* eventually we will want to use PNPMODE_STATIC here but for now
381		 * dynamic will help us catch buggy bioses to add to the blacklist.
382		 */
383		if (!pnpbios_dont_use_current_config) {
384			if (pnp_bios_get_dev_node
385			    (&nodenum, (char)PNPMODE_DYNAMIC, node))
386				break;
387		} else {
388			if (pnp_bios_get_dev_node
389			    (&nodenum, (char)PNPMODE_STATIC, node))
390				break;
391		}
392		nodes_got++;
393		dev = kzalloc(sizeof(struct pnp_dev), GFP_KERNEL);
394		if (!dev)
395			break;
396		if (insert_device(dev, node) < 0)
397			kfree(dev);
398		else
399			devs++;
400		if (nodenum <= thisnodenum) {
401			printk(KERN_ERR
402			       "PnPBIOS: build_devlist: Node number 0x%x is out of sequence following node 0x%x. Aborting.\n",
403			       (unsigned int)nodenum,
404			       (unsigned int)thisnodenum);
405			break;
406		}
407	}
408	kfree(node);
409
410	printk(KERN_INFO
411	       "PnPBIOS: %i node%s reported by PnP BIOS; %i recorded by driver\n",
412	       nodes_got, nodes_got != 1 ? "s" : "", devs);
413}
414
415/*
416 *
417 * INIT AND EXIT
418 *
419 */
420
421static int pnpbios_disabled;	/* = 0 */
422int pnpbios_dont_use_current_config;	/* = 0 */
423
424#ifndef MODULE
425static int __init pnpbios_setup(char *str)
426{
427	int invert;
428
429	while ((str != NULL) && (*str != '\0')) {
430		if (strncmp(str, "off", 3) == 0)
431			pnpbios_disabled = 1;
432		if (strncmp(str, "on", 2) == 0)
433			pnpbios_disabled = 0;
434		invert = (strncmp(str, "no-", 3) == 0);
435		if (invert)
436			str += 3;
437		if (strncmp(str, "curr", 4) == 0)
438			pnpbios_dont_use_current_config = invert;
439		str = strchr(str, ',');
440		if (str != NULL)
441			str += strspn(str, ", \t");
442	}
443
444	return 1;
445}
446
447__setup("pnpbios=", pnpbios_setup);
448#endif
449
450/* PnP BIOS signature: "$PnP" */
451#define PNP_SIGNATURE   (('$' << 0) + ('P' << 8) + ('n' << 16) + ('P' << 24))
452
453static int __init pnpbios_probe_system(void)
454{
455	union pnp_bios_install_struct *check;
456	u8 sum;
457	int length, i;
458
459	printk(KERN_INFO "PnPBIOS: Scanning system for PnP BIOS support...\n");
460
461	/*
462	 * Search the defined area (0xf0000-0xffff0) for a valid PnP BIOS
463	 * structure and, if one is found, sets up the selectors and
464	 * entry points
465	 */
466	for (check = (union pnp_bios_install_struct *)__va(0xf0000);
467	     check < (union pnp_bios_install_struct *)__va(0xffff0);
468	     check = (void *)check + 16) {
469		if (check->fields.signature != PNP_SIGNATURE)
470			continue;
471		printk(KERN_INFO
472		       "PnPBIOS: Found PnP BIOS installation structure at 0x%p\n",
473		       check);
474		length = check->fields.length;
475		if (!length) {
476			printk(KERN_ERR
477			       "PnPBIOS: installation structure is invalid, skipping\n");
478			continue;
479		}
480		for (sum = 0, i = 0; i < length; i++)
481			sum += check->chars[i];
482		if (sum) {
483			printk(KERN_ERR
484			       "PnPBIOS: installation structure is corrupted, skipping\n");
485			continue;
486		}
487		if (check->fields.version < 0x10) {
488			printk(KERN_WARNING
489			       "PnPBIOS: PnP BIOS version %d.%d is not supported\n",
490			       check->fields.version >> 4,
491			       check->fields.version & 15);
492			continue;
493		}
494		printk(KERN_INFO
495		       "PnPBIOS: PnP BIOS version %d.%d, entry 0x%x:0x%x, dseg 0x%x\n",
496		       check->fields.version >> 4, check->fields.version & 15,
497		       check->fields.pm16cseg, check->fields.pm16offset,
498		       check->fields.pm16dseg);
499		pnp_bios_install = check;
500		return 1;
501	}
502
503	printk(KERN_INFO "PnPBIOS: PnP BIOS support was not detected.\n");
504	return 0;
505}
506
507static int __init exploding_pnp_bios(struct dmi_system_id *d)
508{
509	printk(KERN_WARNING "%s detected. Disabling PnPBIOS\n", d->ident);
510	return 0;
511}
512
513static struct dmi_system_id pnpbios_dmi_table[] __initdata = {
514	{			/* PnPBIOS GPF on boot */
515	 .callback = exploding_pnp_bios,
516	 .ident = "Higraded P14H",
517	 .matches = {
518		     DMI_MATCH(DMI_BIOS_VENDOR, "American Megatrends Inc."),
519		     DMI_MATCH(DMI_BIOS_VERSION, "07.00T"),
520		     DMI_MATCH(DMI_SYS_VENDOR, "Higraded"),
521		     DMI_MATCH(DMI_PRODUCT_NAME, "P14H"),
522		     },
523	 },
524	{			/* PnPBIOS GPF on boot */
525	 .callback = exploding_pnp_bios,
526	 .ident = "ASUS P4P800",
527	 .matches = {
528		     DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer Inc."),
529		     DMI_MATCH(DMI_BOARD_NAME, "P4P800"),
530		     },
531	 },
532	{}
533};
534
535static int __init pnpbios_init(void)
536{
537	int ret;
538
539#if defined(CONFIG_PPC_MERGE)
540	if (check_legacy_ioport(PNPBIOS_BASE))
541		return -ENODEV;
542#endif
543	if (pnpbios_disabled || dmi_check_system(pnpbios_dmi_table) ||
544	    paravirt_enabled()) {
545		printk(KERN_INFO "PnPBIOS: Disabled\n");
546		return -ENODEV;
547	}
548#ifdef CONFIG_PNPACPI
549	if (!acpi_disabled && !pnpacpi_disabled) {
550		pnpbios_disabled = 1;
551		printk(KERN_INFO "PnPBIOS: Disabled by ACPI PNP\n");
552		return -ENODEV;
553	}
554#endif /* CONFIG_ACPI */
555
556	/* scan the system for pnpbios support */
557	if (!pnpbios_probe_system())
558		return -ENODEV;
559
560	/* make preparations for bios calls */
561	pnpbios_calls_init(pnp_bios_install);
562
563	/* read the node info */
564	ret = pnp_bios_dev_node_info(&node_info);
565	if (ret) {
566		printk(KERN_ERR
567		       "PnPBIOS: Unable to get node info.  Aborting.\n");
568		return ret;
569	}
570
571	/* register with the pnp layer */
572	ret = pnp_register_protocol(&pnpbios_protocol);
573	if (ret) {
574		printk(KERN_ERR
575		       "PnPBIOS: Unable to register driver.  Aborting.\n");
576		return ret;
577	}
578
579	/* start the proc interface */
580	ret = pnpbios_proc_init();
581	if (ret)
582		printk(KERN_ERR "PnPBIOS: Failed to create proc interface.\n");
583
584	/* scan for pnpbios devices */
585	build_devlist();
586
587	pnp_platform_devices = 1;
588	return 0;
589}
590
591subsys_initcall(pnpbios_init);
592
593static int __init pnpbios_thread_init(void)
594{
595	struct task_struct *task;
596#if defined(CONFIG_PPC_MERGE)
597	if (check_legacy_ioport(PNPBIOS_BASE))
598		return 0;
599#endif
600	if (pnpbios_disabled)
601		return 0;
602#ifdef CONFIG_HOTPLUG
603	init_completion(&unload_sem);
604	task = kthread_run(pnp_dock_thread, NULL, "kpnpbiosd");
605	if (!IS_ERR(task))
606		unloading = 0;
607#endif
608	return 0;
609}
610
611#ifndef MODULE
612
613/* init/main.c calls pnpbios_init early */
614
615/* Start the kernel thread later: */
616module_init(pnpbios_thread_init);
617
618#else
619
620/*
621 * N.B.: Building pnpbios as a module hasn't been fully implemented
622 */
623
624MODULE_LICENSE("GPL");
625
626static int __init pnpbios_init_all(void)
627{
628	int r;
629
630	r = pnpbios_init();
631	if (r)
632		return r;
633	r = pnpbios_thread_init();
634	if (r)
635		return r;
636	return 0;
637}
638
639static void __exit pnpbios_exit(void)
640{
641#ifdef CONFIG_HOTPLUG
642	unloading = 1;
643	wait_for_completion(&unload_sem);
644#endif
645	pnpbios_proc_exit();
646	/* We ought to free resources here */
647	return;
648}
649
650module_init(pnpbios_init_all);
651module_exit(pnpbios_exit);
652
653#endif
654
655EXPORT_SYMBOL(pnpbios_protocol);
656