1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * pnpbios -- PnP BIOS driver
4 *
5 * This driver provides access to Plug-'n'-Play services provided by
6 * the PnP BIOS firmware, described in the following documents:
7 *   Plug and Play BIOS Specification, Version 1.0A, 5 May 1994
8 *   Plug and Play BIOS Clarification Paper, 6 October 1994
9 *     Compaq Computer Corporation, Phoenix Technologies Ltd., Intel Corp.
10 *
11 * Originally (C) 1998 Christian Schmidt <schmidt@digadd.de>
12 * Modifications (C) 1998 Tom Lees <tom@lpsg.demon.co.uk>
13 * Minor reorganizations by David Hinds <dahinds@users.sourceforge.net>
14 * Further modifications (C) 2001, 2002 by:
15 *   Alan Cox <alan@redhat.com>
16 *   Thomas Hood
17 *   Brian Gerst <bgerst@didntduck.org>
18 *
19 * Ported to the PnP Layer and several additional improvements (C) 2002
20 * by Adam Belay <ambx1@neo.rr.com>
21 */
22
23/* Change Log
24 *
25 * Adam Belay - <ambx1@neo.rr.com> - March 16, 2003
26 * rev 1.01	Only call pnp_bios_dev_node_info once
27 *		Added pnpbios_print_status
28 *		Added several new error messages and info messages
29 *		Added pnpbios_interface_attach_device
30 *		integrated core and proc init system
31 *		Introduced PNPMODE flags
32 *		Removed some useless includes
33 */
34
35#include <linux/types.h>
36#include <linux/init.h>
37#include <linux/linkage.h>
38#include <linux/kernel.h>
39#include <linux/device.h>
40#include <linux/pnp.h>
41#include <linux/mm.h>
42#include <linux/smp.h>
43#include <linux/slab.h>
44#include <linux/completion.h>
45#include <linux/spinlock.h>
46#include <linux/dmi.h>
47#include <linux/delay.h>
48#include <linux/acpi.h>
49#include <linux/freezer.h>
50#include <linux/kmod.h>
51#include <linux/kthread.h>
52
53#include <asm/page.h>
54#include <asm/desc.h>
55#include <asm/byteorder.h>
56
57#include "../base.h"
58#include "pnpbios.h"
59
60/*
61 *
62 * PnP BIOS INTERFACE
63 *
64 */
65
66static union pnp_bios_install_struct *pnp_bios_install = NULL;
67
68int pnp_bios_present(void)
69{
70	return (pnp_bios_install != NULL);
71}
72
73struct pnp_dev_node_info node_info;
74
75/*
76 *
77 * DOCKING FUNCTIONS
78 *
79 */
80
81static struct completion unload_sem;
82
83/*
84 * (Much of this belongs in a shared routine somewhere)
85 */
86static int pnp_dock_event(int dock, struct pnp_docking_station_info *info)
87{
88	static char const sbin_pnpbios[] = "/sbin/pnpbios";
89	char *argv[3], **envp, *buf, *scratch;
90	int i = 0, value;
91
92	if (!(envp = kcalloc(20, sizeof(char *), GFP_KERNEL)))
93		return -ENOMEM;
94	if (!(buf = kzalloc(256, GFP_KERNEL))) {
95		kfree(envp);
96		return -ENOMEM;
97	}
98
99	/* FIXME: if there are actual users of this, it should be
100	 * integrated into the driver core and use the usual infrastructure
101	 * like sysfs and uevents
102	 */
103	argv[0] = (char *)sbin_pnpbios;
104	argv[1] = "dock";
105	argv[2] = NULL;
106
107	/* minimal command environment */
108	envp[i++] = "HOME=/";
109	envp[i++] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin";
110
111#ifdef	DEBUG
112	/* hint that policy agent should enter no-stdout debug mode */
113	envp[i++] = "DEBUG=kernel";
114#endif
115	/* extensible set of named bus-specific parameters,
116	 * supporting multiple driver selection algorithms.
117	 */
118	scratch = buf;
119
120	/* action:  add, remove */
121	envp[i++] = scratch;
122	scratch += sprintf(scratch, "ACTION=%s", dock ? "add" : "remove") + 1;
123
124	/* Report the ident for the dock */
125	envp[i++] = scratch;
126	scratch += sprintf(scratch, "DOCK=%x/%x/%x",
127			   info->location_id, info->serial, info->capabilities);
128	envp[i] = NULL;
129
130	value = call_usermodehelper(sbin_pnpbios, argv, envp, UMH_WAIT_EXEC);
131	kfree(buf);
132	kfree(envp);
133	return 0;
134}
135
136/*
137 * Poll the PnP docking at regular intervals
138 */
139static int pnp_dock_thread(void *unused)
140{
141	static struct pnp_docking_station_info now;
142	int docked = -1, d = 0;
143
144	set_freezable();
145	while (1) {
146		int status;
147
148		/*
149		 * Poll every 2 seconds
150		 */
151		msleep_interruptible(2000);
152
153		if (try_to_freeze())
154			continue;
155
156		status = pnp_bios_dock_station_info(&now);
157
158		switch (status) {
159			/*
160			 * No dock to manage
161			 */
162		case PNP_FUNCTION_NOT_SUPPORTED:
163			kthread_complete_and_exit(&unload_sem, 0);
164		case PNP_SYSTEM_NOT_DOCKED:
165			d = 0;
166			break;
167		case PNP_SUCCESS:
168			d = 1;
169			break;
170		default:
171			pnpbios_print_status("pnp_dock_thread", status);
172			printk(KERN_WARNING "PnPBIOS: disabling dock monitoring.\n");
173			kthread_complete_and_exit(&unload_sem, 0);
174		}
175		if (d != docked) {
176			if (pnp_dock_event(d, &now) == 0) {
177				docked = d;
178#if 0
179				printk(KERN_INFO
180				       "PnPBIOS: Docking station %stached\n",
181				       docked ? "at" : "de");
182#endif
183			}
184		}
185	}
186	kthread_complete_and_exit(&unload_sem, 0);
187}
188
189static int pnpbios_get_resources(struct pnp_dev *dev)
190{
191	u8 nodenum = dev->number;
192	struct pnp_bios_node *node;
193
194	if (!pnpbios_is_dynamic(dev))
195		return -EPERM;
196
197	pnp_dbg(&dev->dev, "get resources\n");
198	node = kzalloc(node_info.max_node_size, GFP_KERNEL);
199	if (!node)
200		return -1;
201	if (pnp_bios_get_dev_node(&nodenum, (char)PNPMODE_DYNAMIC, node)) {
202		kfree(node);
203		return -ENODEV;
204	}
205	pnpbios_read_resources_from_node(dev, node);
206	dev->active = pnp_is_active(dev);
207	kfree(node);
208	return 0;
209}
210
211static int pnpbios_set_resources(struct pnp_dev *dev)
212{
213	u8 nodenum = dev->number;
214	struct pnp_bios_node *node;
215	int ret;
216
217	if (!pnpbios_is_dynamic(dev))
218		return -EPERM;
219
220	pnp_dbg(&dev->dev, "set resources\n");
221	node = kzalloc(node_info.max_node_size, GFP_KERNEL);
222	if (!node)
223		return -1;
224	if (pnp_bios_get_dev_node(&nodenum, (char)PNPMODE_DYNAMIC, node)) {
225		kfree(node);
226		return -ENODEV;
227	}
228	if (pnpbios_write_resources_to_node(dev, node) < 0) {
229		kfree(node);
230		return -1;
231	}
232	ret = pnp_bios_set_dev_node(node->handle, (char)PNPMODE_DYNAMIC, node);
233	kfree(node);
234	if (ret > 0)
235		ret = -1;
236	return ret;
237}
238
239static void pnpbios_zero_data_stream(struct pnp_bios_node *node)
240{
241	unsigned char *p = (char *)node->data;
242	unsigned char *end = (char *)(node->data + node->size);
243	unsigned int len;
244	int i;
245
246	while ((char *)p < (char *)end) {
247		if (p[0] & 0x80) {	/* large tag */
248			len = (p[2] << 8) | p[1];
249			p += 3;
250		} else {
251			if (((p[0] >> 3) & 0x0f) == 0x0f)
252				return;
253			len = p[0] & 0x07;
254			p += 1;
255		}
256		for (i = 0; i < len; i++)
257			p[i] = 0;
258		p += len;
259	}
260	printk(KERN_ERR
261	       "PnPBIOS: Resource structure did not contain an end tag.\n");
262}
263
264static int pnpbios_disable_resources(struct pnp_dev *dev)
265{
266	struct pnp_bios_node *node;
267	u8 nodenum = dev->number;
268	int ret;
269
270	if (dev->flags & PNPBIOS_NO_DISABLE || !pnpbios_is_dynamic(dev))
271		return -EPERM;
272
273	node = kzalloc(node_info.max_node_size, GFP_KERNEL);
274	if (!node)
275		return -ENOMEM;
276
277	if (pnp_bios_get_dev_node(&nodenum, (char)PNPMODE_DYNAMIC, node)) {
278		kfree(node);
279		return -ENODEV;
280	}
281	pnpbios_zero_data_stream(node);
282
283	ret = pnp_bios_set_dev_node(dev->number, (char)PNPMODE_DYNAMIC, node);
284	kfree(node);
285	if (ret > 0)
286		ret = -1;
287	return ret;
288}
289
290/* PnP Layer support */
291
292struct pnp_protocol pnpbios_protocol = {
293	.name = "Plug and Play BIOS",
294	.get = pnpbios_get_resources,
295	.set = pnpbios_set_resources,
296	.disable = pnpbios_disable_resources,
297};
298
299static int __init insert_device(struct pnp_bios_node *node)
300{
301	struct pnp_dev *dev;
302	char id[8];
303	int error;
304
305	/* check if the device is already added */
306	list_for_each_entry(dev, &pnpbios_protocol.devices, protocol_list) {
307		if (dev->number == node->handle)
308			return -EEXIST;
309	}
310
311	pnp_eisa_id_to_string(node->eisa_id & PNP_EISA_ID_MASK, id);
312	dev = pnp_alloc_dev(&pnpbios_protocol, node->handle, id);
313	if (!dev)
314		return -ENOMEM;
315
316	pnpbios_parse_data_stream(dev, node);
317	dev->active = pnp_is_active(dev);
318	dev->flags = node->flags;
319	if (!(dev->flags & PNPBIOS_NO_CONFIG))
320		dev->capabilities |= PNP_CONFIGURABLE;
321	if (!(dev->flags & PNPBIOS_NO_DISABLE) && pnpbios_is_dynamic(dev))
322		dev->capabilities |= PNP_DISABLE;
323	dev->capabilities |= PNP_READ;
324	if (pnpbios_is_dynamic(dev))
325		dev->capabilities |= PNP_WRITE;
326	if (dev->flags & PNPBIOS_REMOVABLE)
327		dev->capabilities |= PNP_REMOVABLE;
328
329	/* clear out the damaged flags */
330	if (!dev->active)
331		pnp_init_resources(dev);
332
333	error = pnp_add_device(dev);
334	if (error) {
335		put_device(&dev->dev);
336		return error;
337	}
338
339	pnpbios_interface_attach_device(node);
340
341	return 0;
342}
343
344static void __init build_devlist(void)
345{
346	u8 nodenum;
347	unsigned int nodes_got = 0;
348	unsigned int devs = 0;
349	struct pnp_bios_node *node;
350
351	node = kzalloc(node_info.max_node_size, GFP_KERNEL);
352	if (!node)
353		return;
354
355	for (nodenum = 0; nodenum < 0xff;) {
356		u8 thisnodenum = nodenum;
357		/* eventually we will want to use PNPMODE_STATIC here but for now
358		 * dynamic will help us catch buggy bioses to add to the blacklist.
359		 */
360		if (!pnpbios_dont_use_current_config) {
361			if (pnp_bios_get_dev_node
362			    (&nodenum, (char)PNPMODE_DYNAMIC, node))
363				break;
364		} else {
365			if (pnp_bios_get_dev_node
366			    (&nodenum, (char)PNPMODE_STATIC, node))
367				break;
368		}
369		nodes_got++;
370		if (insert_device(node) == 0)
371			devs++;
372		if (nodenum <= thisnodenum) {
373			printk(KERN_ERR
374			       "PnPBIOS: build_devlist: Node number 0x%x is out of sequence following node 0x%x. Aborting.\n",
375			       (unsigned int)nodenum,
376			       (unsigned int)thisnodenum);
377			break;
378		}
379	}
380	kfree(node);
381
382	printk(KERN_INFO
383	       "PnPBIOS: %i node%s reported by PnP BIOS; %i recorded by driver\n",
384	       nodes_got, nodes_got != 1 ? "s" : "", devs);
385}
386
387/*
388 *
389 * INIT AND EXIT
390 *
391 */
392
393static int pnpbios_disabled;
394int pnpbios_dont_use_current_config;
395
396static int __init pnpbios_setup(char *str)
397{
398	int invert;
399
400	while ((str != NULL) && (*str != '\0')) {
401		if (strncmp(str, "off", 3) == 0)
402			pnpbios_disabled = 1;
403		if (strncmp(str, "on", 2) == 0)
404			pnpbios_disabled = 0;
405		invert = (strncmp(str, "no-", 3) == 0);
406		if (invert)
407			str += 3;
408		if (strncmp(str, "curr", 4) == 0)
409			pnpbios_dont_use_current_config = invert;
410		str = strchr(str, ',');
411		if (str != NULL)
412			str += strspn(str, ", \t");
413	}
414
415	return 1;
416}
417
418__setup("pnpbios=", pnpbios_setup);
419
420/* PnP BIOS signature: "$PnP" */
421#define PNP_SIGNATURE   (('$' << 0) + ('P' << 8) + ('n' << 16) + ('P' << 24))
422
423static int __init pnpbios_probe_system(void)
424{
425	union pnp_bios_install_struct *check;
426	u8 sum;
427	int length, i;
428
429	printk(KERN_INFO "PnPBIOS: Scanning system for PnP BIOS support...\n");
430
431	/*
432	 * Search the defined area (0xf0000-0xffff0) for a valid PnP BIOS
433	 * structure and, if one is found, sets up the selectors and
434	 * entry points
435	 */
436	for (check = (union pnp_bios_install_struct *)__va(0xf0000);
437	     check < (union pnp_bios_install_struct *)__va(0xffff0);
438	     check = (void *)check + 16) {
439		if (check->fields.signature != PNP_SIGNATURE)
440			continue;
441		printk(KERN_INFO
442		       "PnPBIOS: Found PnP BIOS installation structure at 0x%p\n",
443		       check);
444		length = check->fields.length;
445		if (!length) {
446			printk(KERN_ERR
447			       "PnPBIOS: installation structure is invalid, skipping\n");
448			continue;
449		}
450		for (sum = 0, i = 0; i < length; i++)
451			sum += check->chars[i];
452		if (sum) {
453			printk(KERN_ERR
454			       "PnPBIOS: installation structure is corrupted, skipping\n");
455			continue;
456		}
457		if (check->fields.version < 0x10) {
458			printk(KERN_WARNING
459			       "PnPBIOS: PnP BIOS version %d.%d is not supported\n",
460			       check->fields.version >> 4,
461			       check->fields.version & 15);
462			continue;
463		}
464		printk(KERN_INFO
465		       "PnPBIOS: PnP BIOS version %d.%d, entry 0x%x:0x%x, dseg 0x%x\n",
466		       check->fields.version >> 4, check->fields.version & 15,
467		       check->fields.pm16cseg, check->fields.pm16offset,
468		       check->fields.pm16dseg);
469		pnp_bios_install = check;
470		return 1;
471	}
472
473	printk(KERN_INFO "PnPBIOS: PnP BIOS support was not detected.\n");
474	return 0;
475}
476
477static int __init exploding_pnp_bios(const struct dmi_system_id *d)
478{
479	printk(KERN_WARNING "%s detected. Disabling PnPBIOS\n", d->ident);
480	return 0;
481}
482
483static const struct dmi_system_id pnpbios_dmi_table[] __initconst = {
484	{			/* PnPBIOS GPF on boot */
485	 .callback = exploding_pnp_bios,
486	 .ident = "Higraded P14H",
487	 .matches = {
488		     DMI_MATCH(DMI_BIOS_VENDOR, "American Megatrends Inc."),
489		     DMI_MATCH(DMI_BIOS_VERSION, "07.00T"),
490		     DMI_MATCH(DMI_SYS_VENDOR, "Higraded"),
491		     DMI_MATCH(DMI_PRODUCT_NAME, "P14H"),
492		     },
493	 },
494	{			/* PnPBIOS GPF on boot */
495	 .callback = exploding_pnp_bios,
496	 .ident = "ASUS P4P800",
497	 .matches = {
498		     DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer Inc."),
499		     DMI_MATCH(DMI_BOARD_NAME, "P4P800"),
500		     },
501	 },
502	{}
503};
504
505static int __init pnpbios_init(void)
506{
507	int ret;
508
509	if (pnpbios_disabled || dmi_check_system(pnpbios_dmi_table) ||
510	    arch_pnpbios_disabled()) {
511		printk(KERN_INFO "PnPBIOS: Disabled\n");
512		return -ENODEV;
513	}
514
515#ifdef CONFIG_PNPACPI
516	if (!acpi_disabled && !pnpacpi_disabled) {
517		pnpbios_disabled = 1;
518		printk(KERN_INFO "PnPBIOS: Disabled by ACPI PNP\n");
519		return -ENODEV;
520	}
521#endif				/* CONFIG_ACPI */
522
523	/* scan the system for pnpbios support */
524	if (!pnpbios_probe_system())
525		return -ENODEV;
526
527	/* make preparations for bios calls */
528	pnpbios_calls_init(pnp_bios_install);
529
530	/* read the node info */
531	ret = pnp_bios_dev_node_info(&node_info);
532	if (ret) {
533		printk(KERN_ERR
534		       "PnPBIOS: Unable to get node info.  Aborting.\n");
535		return ret;
536	}
537
538	/* register with the pnp layer */
539	ret = pnp_register_protocol(&pnpbios_protocol);
540	if (ret) {
541		printk(KERN_ERR
542		       "PnPBIOS: Unable to register driver.  Aborting.\n");
543		return ret;
544	}
545
546	/* start the proc interface */
547	ret = pnpbios_proc_init();
548	if (ret)
549		printk(KERN_ERR "PnPBIOS: Failed to create proc interface.\n");
550
551	/* scan for pnpbios devices */
552	build_devlist();
553
554	pnp_platform_devices = 1;
555	return 0;
556}
557
558fs_initcall(pnpbios_init);
559
560static int __init pnpbios_thread_init(void)
561{
562	struct task_struct *task;
563
564	if (pnpbios_disabled)
565		return 0;
566
567	init_completion(&unload_sem);
568	task = kthread_run(pnp_dock_thread, NULL, "kpnpbiosd");
569	return PTR_ERR_OR_ZERO(task);
570}
571
572/* Start the kernel thread later: */
573device_initcall(pnpbios_thread_init);
574
575EXPORT_SYMBOL(pnpbios_protocol);
576