core.c revision 68e1ee62f0f8e556642a59ebaf0c2cc2ac6ccfa6 
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/system.h>
69#include <asm/byteorder.h>
70
71#include "../base.h"
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 (!(envp = kcalloc(20, sizeof(char *), GFP_KERNEL)))
109		return -ENOMEM;
110	if (!(buf = kzalloc(256, GFP_KERNEL))) {
111		kfree(envp);
112		return -ENOMEM;
113	}
114
115	/* FIXME: if there are actual users of this, it should be
116	 * integrated into the driver core and use the usual infrastructure
117	 * like sysfs and uevents
118	 */
119	argv[0] = "/sbin/pnpbios";
120	argv[1] = "dock";
121	argv[2] = NULL;
122
123	/* minimal command environment */
124	envp[i++] = "HOME=/";
125	envp[i++] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin";
126
127#ifdef	DEBUG
128	/* hint that policy agent should enter no-stdout debug mode */
129	envp[i++] = "DEBUG=kernel";
130#endif
131	/* extensible set of named bus-specific parameters,
132	 * supporting multiple driver selection algorithms.
133	 */
134	scratch = buf;
135
136	/* action:  add, remove */
137	envp[i++] = scratch;
138	scratch += sprintf(scratch, "ACTION=%s", dock ? "add" : "remove") + 1;
139
140	/* Report the ident for the dock */
141	envp[i++] = scratch;
142	scratch += sprintf(scratch, "DOCK=%x/%x/%x",
143			   info->location_id, info->serial, info->capabilities);
144	envp[i] = NULL;
145
146	value = call_usermodehelper(argv [0], argv, envp, UMH_WAIT_EXEC);
147	kfree(buf);
148	kfree(envp);
149	return 0;
150}
151
152/*
153 * Poll the PnP docking at regular intervals
154 */
155static int pnp_dock_thread(void *unused)
156{
157	static struct pnp_docking_station_info now;
158	int docked = -1, d = 0;
159
160	set_freezable();
161	while (!unloading) {
162		int status;
163
164		/*
165		 * Poll every 2 seconds
166		 */
167		msleep_interruptible(2000);
168
169		if (try_to_freeze())
170			continue;
171
172		status = pnp_bios_dock_station_info(&now);
173
174		switch (status) {
175			/*
176			 * No dock to manage
177			 */
178		case PNP_FUNCTION_NOT_SUPPORTED:
179			complete_and_exit(&unload_sem, 0);
180		case PNP_SYSTEM_NOT_DOCKED:
181			d = 0;
182			break;
183		case PNP_SUCCESS:
184			d = 1;
185			break;
186		default:
187			pnpbios_print_status("pnp_dock_thread", status);
188			continue;
189		}
190		if (d != docked) {
191			if (pnp_dock_event(d, &now) == 0) {
192				docked = d;
193#if 0
194				printk(KERN_INFO
195				       "PnPBIOS: Docking station %stached\n",
196				       docked ? "at" : "de");
197#endif
198			}
199		}
200	}
201	complete_and_exit(&unload_sem, 0);
202}
203
204#endif				/* CONFIG_HOTPLUG */
205
206static int pnpbios_get_resources(struct pnp_dev *dev)
207{
208	u8 nodenum = dev->number;
209	struct pnp_bios_node *node;
210
211	if (!pnpbios_is_dynamic(dev))
212		return -EPERM;
213
214	dev_dbg(&dev->dev, "get resources\n");
215	node = kzalloc(node_info.max_node_size, GFP_KERNEL);
216	if (!node)
217		return -1;
218	if (pnp_bios_get_dev_node(&nodenum, (char)PNPMODE_DYNAMIC, node)) {
219		kfree(node);
220		return -ENODEV;
221	}
222	pnpbios_read_resources_from_node(dev, node);
223	dev->active = pnp_is_active(dev);
224	kfree(node);
225	return 0;
226}
227
228static int pnpbios_set_resources(struct pnp_dev *dev)
229{
230	u8 nodenum = dev->number;
231	struct pnp_bios_node *node;
232	int ret;
233
234	if (!pnpbios_is_dynamic(dev))
235		return -EPERM;
236
237	dev_dbg(&dev->dev, "set resources\n");
238	node = kzalloc(node_info.max_node_size, GFP_KERNEL);
239	if (!node)
240		return -1;
241	if (pnp_bios_get_dev_node(&nodenum, (char)PNPMODE_DYNAMIC, node)) {
242		kfree(node);
243		return -ENODEV;
244	}
245	if (pnpbios_write_resources_to_node(dev, node) < 0) {
246		kfree(node);
247		return -1;
248	}
249	ret = pnp_bios_set_dev_node(node->handle, (char)PNPMODE_DYNAMIC, node);
250	kfree(node);
251	if (ret > 0)
252		ret = -1;
253	return ret;
254}
255
256static void pnpbios_zero_data_stream(struct pnp_bios_node *node)
257{
258	unsigned char *p = (char *)node->data;
259	unsigned char *end = (char *)(node->data + node->size);
260	unsigned int len;
261	int i;
262
263	while ((char *)p < (char *)end) {
264		if (p[0] & 0x80) {	/* large tag */
265			len = (p[2] << 8) | p[1];
266			p += 3;
267		} else {
268			if (((p[0] >> 3) & 0x0f) == 0x0f)
269				return;
270			len = p[0] & 0x07;
271			p += 1;
272		}
273		for (i = 0; i < len; i++)
274			p[i] = 0;
275		p += len;
276	}
277	printk(KERN_ERR
278	       "PnPBIOS: Resource structure did not contain an end tag.\n");
279}
280
281static int pnpbios_disable_resources(struct pnp_dev *dev)
282{
283	struct pnp_bios_node *node;
284	u8 nodenum = dev->number;
285	int ret;
286
287	if (dev->flags & PNPBIOS_NO_DISABLE || !pnpbios_is_dynamic(dev))
288		return -EPERM;
289
290	node = kzalloc(node_info.max_node_size, GFP_KERNEL);
291	if (!node)
292		return -ENOMEM;
293
294	if (pnp_bios_get_dev_node(&nodenum, (char)PNPMODE_DYNAMIC, node)) {
295		kfree(node);
296		return -ENODEV;
297	}
298	pnpbios_zero_data_stream(node);
299
300	ret = pnp_bios_set_dev_node(dev->number, (char)PNPMODE_DYNAMIC, node);
301	kfree(node);
302	if (ret > 0)
303		ret = -1;
304	return ret;
305}
306
307/* PnP Layer support */
308
309struct pnp_protocol pnpbios_protocol = {
310	.name = "Plug and Play BIOS",
311	.get = pnpbios_get_resources,
312	.set = pnpbios_set_resources,
313	.disable = pnpbios_disable_resources,
314};
315
316static int __init insert_device(struct pnp_bios_node *node)
317{
318	struct list_head *pos;
319	struct pnp_dev *dev;
320	char id[8];
321
322	/* check if the device is already added */
323	list_for_each(pos, &pnpbios_protocol.devices) {
324		dev = list_entry(pos, struct pnp_dev, protocol_list);
325		if (dev->number == node->handle)
326			return -1;
327	}
328
329	pnp_eisa_id_to_string(node->eisa_id & PNP_EISA_ID_MASK, id);
330	dev = pnp_alloc_dev(&pnpbios_protocol, node->handle, id);
331	if (!dev)
332		return -1;
333
334	pnpbios_parse_data_stream(dev, node);
335	dev->active = pnp_is_active(dev);
336	dev->flags = node->flags;
337	if (!(dev->flags & PNPBIOS_NO_CONFIG))
338		dev->capabilities |= PNP_CONFIGURABLE;
339	if (!(dev->flags & PNPBIOS_NO_DISABLE) && pnpbios_is_dynamic(dev))
340		dev->capabilities |= PNP_DISABLE;
341	dev->capabilities |= PNP_READ;
342	if (pnpbios_is_dynamic(dev))
343		dev->capabilities |= PNP_WRITE;
344	if (dev->flags & PNPBIOS_REMOVABLE)
345		dev->capabilities |= PNP_REMOVABLE;
346
347	/* clear out the damaged flags */
348	if (!dev->active)
349		pnp_init_resources(dev);
350
351	pnp_add_device(dev);
352	pnpbios_interface_attach_device(node);
353
354	return 0;
355}
356
357static void __init build_devlist(void)
358{
359	u8 nodenum;
360	unsigned int nodes_got = 0;
361	unsigned int devs = 0;
362	struct pnp_bios_node *node;
363
364	node = kzalloc(node_info.max_node_size, GFP_KERNEL);
365	if (!node)
366		return;
367
368	for (nodenum = 0; nodenum < 0xff;) {
369		u8 thisnodenum = nodenum;
370		/* eventually we will want to use PNPMODE_STATIC here but for now
371		 * dynamic will help us catch buggy bioses to add to the blacklist.
372		 */
373		if (!pnpbios_dont_use_current_config) {
374			if (pnp_bios_get_dev_node
375			    (&nodenum, (char)PNPMODE_DYNAMIC, node))
376				break;
377		} else {
378			if (pnp_bios_get_dev_node
379			    (&nodenum, (char)PNPMODE_STATIC, node))
380				break;
381		}
382		nodes_got++;
383		if (insert_device(node) == 0)
384			devs++;
385		if (nodenum <= thisnodenum) {
386			printk(KERN_ERR
387			       "PnPBIOS: build_devlist: Node number 0x%x is out of sequence following node 0x%x. Aborting.\n",
388			       (unsigned int)nodenum,
389			       (unsigned int)thisnodenum);
390			break;
391		}
392	}
393	kfree(node);
394
395	printk(KERN_INFO
396	       "PnPBIOS: %i node%s reported by PnP BIOS; %i recorded by driver\n",
397	       nodes_got, nodes_got != 1 ? "s" : "", devs);
398}
399
400/*
401 *
402 * INIT AND EXIT
403 *
404 */
405
406static int pnpbios_disabled;
407int pnpbios_dont_use_current_config;
408
409static int __init pnpbios_setup(char *str)
410{
411	int invert;
412
413	while ((str != NULL) && (*str != '\0')) {
414		if (strncmp(str, "off", 3) == 0)
415			pnpbios_disabled = 1;
416		if (strncmp(str, "on", 2) == 0)
417			pnpbios_disabled = 0;
418		invert = (strncmp(str, "no-", 3) == 0);
419		if (invert)
420			str += 3;
421		if (strncmp(str, "curr", 4) == 0)
422			pnpbios_dont_use_current_config = invert;
423		str = strchr(str, ',');
424		if (str != NULL)
425			str += strspn(str, ", \t");
426	}
427
428	return 1;
429}
430
431__setup("pnpbios=", pnpbios_setup);
432
433/* PnP BIOS signature: "$PnP" */
434#define PNP_SIGNATURE   (('$' << 0) + ('P' << 8) + ('n' << 16) + ('P' << 24))
435
436static int __init pnpbios_probe_system(void)
437{
438	union pnp_bios_install_struct *check;
439	u8 sum;
440	int length, i;
441
442	printk(KERN_INFO "PnPBIOS: Scanning system for PnP BIOS support...\n");
443
444	/*
445	 * Search the defined area (0xf0000-0xffff0) for a valid PnP BIOS
446	 * structure and, if one is found, sets up the selectors and
447	 * entry points
448	 */
449	for (check = (union pnp_bios_install_struct *)__va(0xf0000);
450	     check < (union pnp_bios_install_struct *)__va(0xffff0);
451	     check = (void *)check + 16) {
452		if (check->fields.signature != PNP_SIGNATURE)
453			continue;
454		printk(KERN_INFO
455		       "PnPBIOS: Found PnP BIOS installation structure at 0x%p\n",
456		       check);
457		length = check->fields.length;
458		if (!length) {
459			printk(KERN_ERR
460			       "PnPBIOS: installation structure is invalid, skipping\n");
461			continue;
462		}
463		for (sum = 0, i = 0; i < length; i++)
464			sum += check->chars[i];
465		if (sum) {
466			printk(KERN_ERR
467			       "PnPBIOS: installation structure is corrupted, skipping\n");
468			continue;
469		}
470		if (check->fields.version < 0x10) {
471			printk(KERN_WARNING
472			       "PnPBIOS: PnP BIOS version %d.%d is not supported\n",
473			       check->fields.version >> 4,
474			       check->fields.version & 15);
475			continue;
476		}
477		printk(KERN_INFO
478		       "PnPBIOS: PnP BIOS version %d.%d, entry 0x%x:0x%x, dseg 0x%x\n",
479		       check->fields.version >> 4, check->fields.version & 15,
480		       check->fields.pm16cseg, check->fields.pm16offset,
481		       check->fields.pm16dseg);
482		pnp_bios_install = check;
483		return 1;
484	}
485
486	printk(KERN_INFO "PnPBIOS: PnP BIOS support was not detected.\n");
487	return 0;
488}
489
490static int __init exploding_pnp_bios(const struct dmi_system_id *d)
491{
492	printk(KERN_WARNING "%s detected. Disabling PnPBIOS\n", d->ident);
493	return 0;
494}
495
496static struct dmi_system_id pnpbios_dmi_table[] __initdata = {
497	{			/* PnPBIOS GPF on boot */
498	 .callback = exploding_pnp_bios,
499	 .ident = "Higraded P14H",
500	 .matches = {
501		     DMI_MATCH(DMI_BIOS_VENDOR, "American Megatrends Inc."),
502		     DMI_MATCH(DMI_BIOS_VERSION, "07.00T"),
503		     DMI_MATCH(DMI_SYS_VENDOR, "Higraded"),
504		     DMI_MATCH(DMI_PRODUCT_NAME, "P14H"),
505		     },
506	 },
507	{			/* PnPBIOS GPF on boot */
508	 .callback = exploding_pnp_bios,
509	 .ident = "ASUS P4P800",
510	 .matches = {
511		     DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer Inc."),
512		     DMI_MATCH(DMI_BOARD_NAME, "P4P800"),
513		     },
514	 },
515	{}
516};
517
518static int __init pnpbios_init(void)
519{
520	int ret;
521
522#if defined(CONFIG_PPC)
523	if (check_legacy_ioport(PNPBIOS_BASE))
524		return -ENODEV;
525#endif
526	if (pnpbios_disabled || dmi_check_system(pnpbios_dmi_table) ||
527	    paravirt_enabled()) {
528		printk(KERN_INFO "PnPBIOS: Disabled\n");
529		return -ENODEV;
530	}
531#ifdef CONFIG_PNPACPI
532	if (!acpi_disabled && !pnpacpi_disabled) {
533		pnpbios_disabled = 1;
534		printk(KERN_INFO "PnPBIOS: Disabled by ACPI PNP\n");
535		return -ENODEV;
536	}
537#endif				/* CONFIG_ACPI */
538
539	/* scan the system for pnpbios support */
540	if (!pnpbios_probe_system())
541		return -ENODEV;
542
543	/* make preparations for bios calls */
544	pnpbios_calls_init(pnp_bios_install);
545
546	/* read the node info */
547	ret = pnp_bios_dev_node_info(&node_info);
548	if (ret) {
549		printk(KERN_ERR
550		       "PnPBIOS: Unable to get node info.  Aborting.\n");
551		return ret;
552	}
553
554	/* register with the pnp layer */
555	ret = pnp_register_protocol(&pnpbios_protocol);
556	if (ret) {
557		printk(KERN_ERR
558		       "PnPBIOS: Unable to register driver.  Aborting.\n");
559		return ret;
560	}
561
562	/* start the proc interface */
563	ret = pnpbios_proc_init();
564	if (ret)
565		printk(KERN_ERR "PnPBIOS: Failed to create proc interface.\n");
566
567	/* scan for pnpbios devices */
568	build_devlist();
569
570	pnp_platform_devices = 1;
571	return 0;
572}
573
574subsys_initcall(pnpbios_init);
575
576static int __init pnpbios_thread_init(void)
577{
578	struct task_struct *task;
579
580#if defined(CONFIG_PPC)
581	if (check_legacy_ioport(PNPBIOS_BASE))
582		return 0;
583#endif
584	if (pnpbios_disabled)
585		return 0;
586#ifdef CONFIG_HOTPLUG
587	init_completion(&unload_sem);
588	task = kthread_run(pnp_dock_thread, NULL, "kpnpbiosd");
589	if (!IS_ERR(task))
590		unloading = 0;
591#endif
592	return 0;
593}
594
595/* Start the kernel thread later: */
596module_init(pnpbios_thread_init);
597
598EXPORT_SYMBOL(pnpbios_protocol);
599