core.c revision bda1e4e5a3d976046378cd495a63e1ee0847deec 
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 "../base.h"
73#include "pnpbios.h"
74
75/*
76 *
77 * PnP BIOS INTERFACE
78 *
79 */
80
81static union pnp_bios_install_struct *pnp_bios_install = NULL;
82
83int pnp_bios_present(void)
84{
85	return (pnp_bios_install != NULL);
86}
87
88struct pnp_dev_node_info node_info;
89
90/*
91 *
92 * DOCKING FUNCTIONS
93 *
94 */
95
96#ifdef CONFIG_HOTPLUG
97
98static int unloading = 0;
99static struct completion unload_sem;
100
101/*
102 * (Much of this belongs in a shared routine somewhere)
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 (!(envp = kcalloc(20, sizeof(char *), GFP_KERNEL)))
110		return -ENOMEM;
111	if (!(buf = kzalloc(256, GFP_KERNEL))) {
112		kfree(envp);
113		return -ENOMEM;
114	}
115
116	/* FIXME: if there are actual users of this, it should be
117	 * integrated into the driver core and use the usual infrastructure
118	 * like sysfs and uevents
119	 */
120	argv[0] = "/sbin/pnpbios";
121	argv[1] = "dock";
122	argv[2] = NULL;
123
124	/* minimal command environment */
125	envp[i++] = "HOME=/";
126	envp[i++] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin";
127
128#ifdef	DEBUG
129	/* hint that policy agent should enter no-stdout debug mode */
130	envp[i++] = "DEBUG=kernel";
131#endif
132	/* extensible set of named bus-specific parameters,
133	 * supporting multiple driver selection algorithms.
134	 */
135	scratch = buf;
136
137	/* action:  add, remove */
138	envp[i++] = scratch;
139	scratch += sprintf(scratch, "ACTION=%s", dock ? "add" : "remove") + 1;
140
141	/* Report the ident for the dock */
142	envp[i++] = scratch;
143	scratch += sprintf(scratch, "DOCK=%x/%x/%x",
144			   info->location_id, info->serial, info->capabilities);
145	envp[i] = NULL;
146
147	value = call_usermodehelper(argv [0], argv, envp, UMH_WAIT_EXEC);
148	kfree(buf);
149	kfree(envp);
150	return 0;
151}
152
153/*
154 * Poll the PnP docking at regular intervals
155 */
156static int pnp_dock_thread(void *unused)
157{
158	static struct pnp_docking_station_info now;
159	int docked = -1, d = 0;
160
161	set_freezable();
162	while (!unloading) {
163		int status;
164
165		/*
166		 * Poll every 2 seconds
167		 */
168		msleep_interruptible(2000);
169
170		if (try_to_freeze())
171			continue;
172
173		status = pnp_bios_dock_station_info(&now);
174
175		switch (status) {
176			/*
177			 * No dock to manage
178			 */
179		case PNP_FUNCTION_NOT_SUPPORTED:
180			complete_and_exit(&unload_sem, 0);
181		case PNP_SYSTEM_NOT_DOCKED:
182			d = 0;
183			break;
184		case PNP_SUCCESS:
185			d = 1;
186			break;
187		default:
188			pnpbios_print_status("pnp_dock_thread", status);
189			continue;
190		}
191		if (d != docked) {
192			if (pnp_dock_event(d, &now) == 0) {
193				docked = d;
194#if 0
195				printk(KERN_INFO
196				       "PnPBIOS: Docking station %stached\n",
197				       docked ? "at" : "de");
198#endif
199			}
200		}
201	}
202	complete_and_exit(&unload_sem, 0);
203}
204
205#endif				/* CONFIG_HOTPLUG */
206
207static int pnpbios_get_resources(struct pnp_dev *dev,
208				 struct pnp_resource_table *res)
209{
210	u8 nodenum = dev->number;
211	struct pnp_bios_node *node;
212
213	if (!pnpbios_is_dynamic(dev))
214		return -EPERM;
215
216	node = kzalloc(node_info.max_node_size, GFP_KERNEL);
217	if (!node)
218		return -1;
219	if (pnp_bios_get_dev_node(&nodenum, (char)PNPMODE_DYNAMIC, node)) {
220		kfree(node);
221		return -ENODEV;
222	}
223	pnpbios_read_resources_from_node(res, node);
224	dev->active = pnp_is_active(dev);
225	kfree(node);
226	return 0;
227}
228
229static int pnpbios_set_resources(struct pnp_dev *dev,
230				 struct pnp_resource_table *res)
231{
232	u8 nodenum = dev->number;
233	struct pnp_bios_node *node;
234	int ret;
235
236	if (!pnpbios_is_dynamic(dev))
237		return -EPERM;
238
239	node = kzalloc(node_info.max_node_size, GFP_KERNEL);
240	if (!node)
241		return -1;
242	if (pnp_bios_get_dev_node(&nodenum, (char)PNPMODE_DYNAMIC, node)) {
243		kfree(node);
244		return -ENODEV;
245	}
246	if (pnpbios_write_resources_to_node(res, node) < 0) {
247		kfree(node);
248		return -1;
249	}
250	ret = pnp_bios_set_dev_node(node->handle, (char)PNPMODE_DYNAMIC, node);
251	kfree(node);
252	if (ret > 0)
253		ret = -1;
254	return ret;
255}
256
257static void pnpbios_zero_data_stream(struct pnp_bios_node *node)
258{
259	unsigned char *p = (char *)node->data;
260	unsigned char *end = (char *)(node->data + node->size);
261	unsigned int len;
262	int i;
263
264	while ((char *)p < (char *)end) {
265		if (p[0] & 0x80) {	/* large tag */
266			len = (p[2] << 8) | p[1];
267			p += 3;
268		} else {
269			if (((p[0] >> 3) & 0x0f) == 0x0f)
270				return;
271			len = p[0] & 0x07;
272			p += 1;
273		}
274		for (i = 0; i < len; i++)
275			p[i] = 0;
276		p += len;
277	}
278	printk(KERN_ERR
279	       "PnPBIOS: Resource structure did not contain an end tag.\n");
280}
281
282static int pnpbios_disable_resources(struct pnp_dev *dev)
283{
284	struct pnp_bios_node *node;
285	u8 nodenum = dev->number;
286	int ret;
287
288	if (dev->flags & PNPBIOS_NO_DISABLE || !pnpbios_is_dynamic(dev))
289		return -EPERM;
290
291	node = kzalloc(node_info.max_node_size, GFP_KERNEL);
292	if (!node)
293		return -ENOMEM;
294
295	if (pnp_bios_get_dev_node(&nodenum, (char)PNPMODE_DYNAMIC, node)) {
296		kfree(node);
297		return -ENODEV;
298	}
299	pnpbios_zero_data_stream(node);
300
301	ret = pnp_bios_set_dev_node(dev->number, (char)PNPMODE_DYNAMIC, node);
302	kfree(node);
303	if (ret > 0)
304		ret = -1;
305	return ret;
306}
307
308/* PnP Layer support */
309
310struct pnp_protocol pnpbios_protocol = {
311	.name = "Plug and Play BIOS",
312	.get = pnpbios_get_resources,
313	.set = pnpbios_set_resources,
314	.disable = pnpbios_disable_resources,
315};
316
317static int __init insert_device(struct pnp_bios_node *node)
318{
319	struct list_head *pos;
320	struct pnp_dev *dev;
321	char id[8];
322
323	/* check if the device is already added */
324	list_for_each(pos, &pnpbios_protocol.devices) {
325		dev = list_entry(pos, struct pnp_dev, protocol_list);
326		if (dev->number == node->handle)
327			return -1;
328	}
329
330	pnp_eisa_id_to_string(node->eisa_id & PNP_EISA_ID_MASK, id);
331	dev = pnp_alloc_dev(&pnpbios_protocol, node->handle, id);
332	if (!dev)
333		return -1;
334
335	pnpbios_parse_data_stream(dev, node);
336	dev->active = pnp_is_active(dev);
337	dev->flags = node->flags;
338	if (!(dev->flags & PNPBIOS_NO_CONFIG))
339		dev->capabilities |= PNP_CONFIGURABLE;
340	if (!(dev->flags & PNPBIOS_NO_DISABLE) && pnpbios_is_dynamic(dev))
341		dev->capabilities |= PNP_DISABLE;
342	dev->capabilities |= PNP_READ;
343	if (pnpbios_is_dynamic(dev))
344		dev->capabilities |= PNP_WRITE;
345	if (dev->flags & PNPBIOS_REMOVABLE)
346		dev->capabilities |= PNP_REMOVABLE;
347
348	/* clear out the damaged flags */
349	if (!dev->active)
350		pnp_init_resource_table(&dev->res);
351
352	pnp_add_device(dev);
353	pnpbios_interface_attach_device(node);
354
355	return 0;
356}
357
358static void __init build_devlist(void)
359{
360	u8 nodenum;
361	unsigned int nodes_got = 0;
362	unsigned int devs = 0;
363	struct pnp_bios_node *node;
364
365	node = kzalloc(node_info.max_node_size, GFP_KERNEL);
366	if (!node)
367		return;
368
369	for (nodenum = 0; nodenum < 0xff;) {
370		u8 thisnodenum = nodenum;
371		/* eventually we will want to use PNPMODE_STATIC here but for now
372		 * dynamic will help us catch buggy bioses to add to the blacklist.
373		 */
374		if (!pnpbios_dont_use_current_config) {
375			if (pnp_bios_get_dev_node
376			    (&nodenum, (char)PNPMODE_DYNAMIC, node))
377				break;
378		} else {
379			if (pnp_bios_get_dev_node
380			    (&nodenum, (char)PNPMODE_STATIC, node))
381				break;
382		}
383		nodes_got++;
384		if (insert_device(node) == 0)
385			devs++;
386		if (nodenum <= thisnodenum) {
387			printk(KERN_ERR
388			       "PnPBIOS: build_devlist: Node number 0x%x is out of sequence following node 0x%x. Aborting.\n",
389			       (unsigned int)nodenum,
390			       (unsigned int)thisnodenum);
391			break;
392		}
393	}
394	kfree(node);
395
396	printk(KERN_INFO
397	       "PnPBIOS: %i node%s reported by PnP BIOS; %i recorded by driver\n",
398	       nodes_got, nodes_got != 1 ? "s" : "", devs);
399}
400
401/*
402 *
403 * INIT AND EXIT
404 *
405 */
406
407static int pnpbios_disabled;
408int pnpbios_dont_use_current_config;
409
410static int __init pnpbios_setup(char *str)
411{
412	int invert;
413
414	while ((str != NULL) && (*str != '\0')) {
415		if (strncmp(str, "off", 3) == 0)
416			pnpbios_disabled = 1;
417		if (strncmp(str, "on", 2) == 0)
418			pnpbios_disabled = 0;
419		invert = (strncmp(str, "no-", 3) == 0);
420		if (invert)
421			str += 3;
422		if (strncmp(str, "curr", 4) == 0)
423			pnpbios_dont_use_current_config = invert;
424		str = strchr(str, ',');
425		if (str != NULL)
426			str += strspn(str, ", \t");
427	}
428
429	return 1;
430}
431
432__setup("pnpbios=", pnpbios_setup);
433
434/* PnP BIOS signature: "$PnP" */
435#define PNP_SIGNATURE   (('$' << 0) + ('P' << 8) + ('n' << 16) + ('P' << 24))
436
437static int __init pnpbios_probe_system(void)
438{
439	union pnp_bios_install_struct *check;
440	u8 sum;
441	int length, i;
442
443	printk(KERN_INFO "PnPBIOS: Scanning system for PnP BIOS support...\n");
444
445	/*
446	 * Search the defined area (0xf0000-0xffff0) for a valid PnP BIOS
447	 * structure and, if one is found, sets up the selectors and
448	 * entry points
449	 */
450	for (check = (union pnp_bios_install_struct *)__va(0xf0000);
451	     check < (union pnp_bios_install_struct *)__va(0xffff0);
452	     check = (void *)check + 16) {
453		if (check->fields.signature != PNP_SIGNATURE)
454			continue;
455		printk(KERN_INFO
456		       "PnPBIOS: Found PnP BIOS installation structure at 0x%p\n",
457		       check);
458		length = check->fields.length;
459		if (!length) {
460			printk(KERN_ERR
461			       "PnPBIOS: installation structure is invalid, skipping\n");
462			continue;
463		}
464		for (sum = 0, i = 0; i < length; i++)
465			sum += check->chars[i];
466		if (sum) {
467			printk(KERN_ERR
468			       "PnPBIOS: installation structure is corrupted, skipping\n");
469			continue;
470		}
471		if (check->fields.version < 0x10) {
472			printk(KERN_WARNING
473			       "PnPBIOS: PnP BIOS version %d.%d is not supported\n",
474			       check->fields.version >> 4,
475			       check->fields.version & 15);
476			continue;
477		}
478		printk(KERN_INFO
479		       "PnPBIOS: PnP BIOS version %d.%d, entry 0x%x:0x%x, dseg 0x%x\n",
480		       check->fields.version >> 4, check->fields.version & 15,
481		       check->fields.pm16cseg, check->fields.pm16offset,
482		       check->fields.pm16dseg);
483		pnp_bios_install = check;
484		return 1;
485	}
486
487	printk(KERN_INFO "PnPBIOS: PnP BIOS support was not detected.\n");
488	return 0;
489}
490
491static int __init exploding_pnp_bios(const struct dmi_system_id *d)
492{
493	printk(KERN_WARNING "%s detected. Disabling PnPBIOS\n", d->ident);
494	return 0;
495}
496
497static struct dmi_system_id pnpbios_dmi_table[] __initdata = {
498	{			/* PnPBIOS GPF on boot */
499	 .callback = exploding_pnp_bios,
500	 .ident = "Higraded P14H",
501	 .matches = {
502		     DMI_MATCH(DMI_BIOS_VENDOR, "American Megatrends Inc."),
503		     DMI_MATCH(DMI_BIOS_VERSION, "07.00T"),
504		     DMI_MATCH(DMI_SYS_VENDOR, "Higraded"),
505		     DMI_MATCH(DMI_PRODUCT_NAME, "P14H"),
506		     },
507	 },
508	{			/* PnPBIOS GPF on boot */
509	 .callback = exploding_pnp_bios,
510	 .ident = "ASUS P4P800",
511	 .matches = {
512		     DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer Inc."),
513		     DMI_MATCH(DMI_BOARD_NAME, "P4P800"),
514		     },
515	 },
516	{}
517};
518
519static int __init pnpbios_init(void)
520{
521	int ret;
522
523#if defined(CONFIG_PPC_MERGE)
524	if (check_legacy_ioport(PNPBIOS_BASE))
525		return -ENODEV;
526#endif
527	if (pnpbios_disabled || dmi_check_system(pnpbios_dmi_table) ||
528	    paravirt_enabled()) {
529		printk(KERN_INFO "PnPBIOS: Disabled\n");
530		return -ENODEV;
531	}
532#ifdef CONFIG_PNPACPI
533	if (!acpi_disabled && !pnpacpi_disabled) {
534		pnpbios_disabled = 1;
535		printk(KERN_INFO "PnPBIOS: Disabled by ACPI PNP\n");
536		return -ENODEV;
537	}
538#endif				/* CONFIG_ACPI */
539
540	/* scan the system for pnpbios support */
541	if (!pnpbios_probe_system())
542		return -ENODEV;
543
544	/* make preparations for bios calls */
545	pnpbios_calls_init(pnp_bios_install);
546
547	/* read the node info */
548	ret = pnp_bios_dev_node_info(&node_info);
549	if (ret) {
550		printk(KERN_ERR
551		       "PnPBIOS: Unable to get node info.  Aborting.\n");
552		return ret;
553	}
554
555	/* register with the pnp layer */
556	ret = pnp_register_protocol(&pnpbios_protocol);
557	if (ret) {
558		printk(KERN_ERR
559		       "PnPBIOS: Unable to register driver.  Aborting.\n");
560		return ret;
561	}
562
563	/* start the proc interface */
564	ret = pnpbios_proc_init();
565	if (ret)
566		printk(KERN_ERR "PnPBIOS: Failed to create proc interface.\n");
567
568	/* scan for pnpbios devices */
569	build_devlist();
570
571	pnp_platform_devices = 1;
572	return 0;
573}
574
575subsys_initcall(pnpbios_init);
576
577static int __init pnpbios_thread_init(void)
578{
579	struct task_struct *task;
580
581#if defined(CONFIG_PPC_MERGE)
582	if (check_legacy_ioport(PNPBIOS_BASE))
583		return 0;
584#endif
585	if (pnpbios_disabled)
586		return 0;
587#ifdef CONFIG_HOTPLUG
588	init_completion(&unload_sem);
589	task = kthread_run(pnp_dock_thread, NULL, "kpnpbiosd");
590	if (!IS_ERR(task))
591		unloading = 0;
592#endif
593	return 0;
594}
595
596/* Start the kernel thread later: */
597module_init(pnpbios_thread_init);
598
599EXPORT_SYMBOL(pnpbios_protocol);
600