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
66 static union pnp_bios_install_struct *pnp_bios_install = NULL;
67
pnp_bios_present(void)68 int pnp_bios_present(void)
69 {
70 return (pnp_bios_install != NULL);
71 }
72
73 struct pnp_dev_node_info node_info;
74
75 /*
76 *
77 * DOCKING FUNCTIONS
78 *
79 */
80
81 static struct completion unload_sem;
82
83 /*
84 * (Much of this belongs in a shared routine somewhere)
85 */
pnp_dock_event(int dock,struct pnp_docking_station_info * info)86 static 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 */
pnp_dock_thread(void * unused)139 static 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
pnpbios_get_resources(struct pnp_dev * dev)189 static 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
pnpbios_set_resources(struct pnp_dev * dev)211 static 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
pnpbios_zero_data_stream(struct pnp_bios_node * node)239 static 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
pnpbios_disable_resources(struct pnp_dev * dev)264 static 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
292 struct 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
insert_device(struct pnp_bios_node * node)299 static 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
build_devlist(void)344 static 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
393 static int pnpbios_disabled;
394 int pnpbios_dont_use_current_config;
395
pnpbios_setup(char * str)396 static 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
pnpbios_probe_system(void)423 static 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
exploding_pnp_bios(const struct dmi_system_id * d)477 static 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
483 static 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
pnpbios_init(void)505 static 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
558 fs_initcall(pnpbios_init);
559
pnpbios_thread_init(void)560 static 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: */
573 device_initcall(pnpbios_thread_init);
574
575 EXPORT_SYMBOL(pnpbios_protocol);
576