core.c revision 1e0aa9ad721349781b728ec4226876247e3fd431 
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 */
103static 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 */
157static 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
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	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
230static 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
258static 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
283static 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
311struct 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
318static 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
364static 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
419static int pnpbios_disabled;
420int pnpbios_dont_use_current_config;
421
422#ifndef MODULE
423static 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
451static 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
505static 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
511static 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
533static 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
589subsys_initcall(pnpbios_init);
590
591static int __init pnpbios_thread_init(void)
592{
593	struct task_struct *task;
594
595#if defined(CONFIG_PPC_MERGE)
596	if (check_legacy_ioport(PNPBIOS_BASE))
597		return 0;
598#endif
599	if (pnpbios_disabled)
600		return 0;
601#ifdef CONFIG_HOTPLUG
602	init_completion(&unload_sem);
603	task = kthread_run(pnp_dock_thread, NULL, "kpnpbiosd");
604	if (!IS_ERR(task))
605		unloading = 0;
606#endif
607	return 0;
608}
609
610#ifndef MODULE
611
612/* init/main.c calls pnpbios_init early */
613
614/* Start the kernel thread later: */
615module_init(pnpbios_thread_init);
616
617#else
618
619/*
620 * N.B.: Building pnpbios as a module hasn't been fully implemented
621 */
622
623MODULE_LICENSE("GPL");
624
625static int __init pnpbios_init_all(void)
626{
627	int r;
628
629	r = pnpbios_init();
630	if (r)
631		return r;
632	r = pnpbios_thread_init();
633	if (r)
634		return r;
635	return 0;
636}
637
638static void __exit pnpbios_exit(void)
639{
640#ifdef CONFIG_HOTPLUG
641	unloading = 1;
642	wait_for_completion(&unload_sem);
643#endif
644	pnpbios_proc_exit();
645	/* We ought to free resources here */
646	return;
647}
648
649module_init(pnpbios_init_all);
650module_exit(pnpbios_exit);
651
652#endif
653
654EXPORT_SYMBOL(pnpbios_protocol);
655