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 | |
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 | */ |
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(n: 20, size: sizeof(char *), GFP_KERNEL))) |
93 | return -ENOMEM; |
94 | if (!(buf = kzalloc(size: 256, GFP_KERNEL))) { |
95 | kfree(objp: 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(buf: scratch, fmt: "ACTION=%s" , dock ? "add" : "remove" ) + 1; |
123 | |
124 | /* Report the ident for the dock */ |
125 | envp[i++] = scratch; |
126 | scratch += sprintf(buf: scratch, fmt: "DOCK=%x/%x/%x" , |
127 | info->location_id, info->serial, info->capabilities); |
128 | envp[i] = NULL; |
129 | |
130 | value = call_usermodehelper(path: sbin_pnpbios, argv, envp, UMH_WAIT_EXEC); |
131 | kfree(objp: buf); |
132 | kfree(objp: envp); |
133 | return 0; |
134 | } |
135 | |
136 | /* |
137 | * Poll the PnP docking at regular intervals |
138 | */ |
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(msecs: 2000); |
152 | |
153 | if (try_to_freeze()) |
154 | continue; |
155 | |
156 | status = pnp_bios_dock_station_info(data: &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(module: "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(dock: d, info: &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 | |
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(size: node_info.max_node_size, GFP_KERNEL); |
199 | if (!node) |
200 | return -1; |
201 | if (pnp_bios_get_dev_node(nodenum: &nodenum, config: (char)PNPMODE_DYNAMIC, data: node)) { |
202 | kfree(objp: node); |
203 | return -ENODEV; |
204 | } |
205 | pnpbios_read_resources_from_node(dev, node); |
206 | dev->active = pnp_is_active(dev); |
207 | kfree(objp: node); |
208 | return 0; |
209 | } |
210 | |
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(size: node_info.max_node_size, GFP_KERNEL); |
222 | if (!node) |
223 | return -1; |
224 | if (pnp_bios_get_dev_node(nodenum: &nodenum, config: (char)PNPMODE_DYNAMIC, data: node)) { |
225 | kfree(objp: node); |
226 | return -ENODEV; |
227 | } |
228 | if (pnpbios_write_resources_to_node(dev, node) < 0) { |
229 | kfree(objp: node); |
230 | return -1; |
231 | } |
232 | ret = pnp_bios_set_dev_node(nodenum: node->handle, config: (char)PNPMODE_DYNAMIC, data: node); |
233 | kfree(objp: node); |
234 | if (ret > 0) |
235 | ret = -1; |
236 | return ret; |
237 | } |
238 | |
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 | |
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(size: node_info.max_node_size, GFP_KERNEL); |
274 | if (!node) |
275 | return -ENOMEM; |
276 | |
277 | if (pnp_bios_get_dev_node(nodenum: &nodenum, config: (char)PNPMODE_DYNAMIC, data: node)) { |
278 | kfree(objp: node); |
279 | return -ENODEV; |
280 | } |
281 | pnpbios_zero_data_stream(node); |
282 | |
283 | ret = pnp_bios_set_dev_node(nodenum: dev->number, config: (char)PNPMODE_DYNAMIC, data: node); |
284 | kfree(objp: 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 | |
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(id: node->eisa_id & PNP_EISA_ID_MASK, str: id); |
312 | dev = pnp_alloc_dev(&pnpbios_protocol, id: node->handle, pnpid: 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->dev); |
336 | return error; |
337 | } |
338 | |
339 | pnpbios_interface_attach_device(node); |
340 | |
341 | return 0; |
342 | } |
343 | |
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(size: 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: &nodenum, config: (char)PNPMODE_DYNAMIC, data: node)) |
363 | break; |
364 | } else { |
365 | if (pnp_bios_get_dev_node |
366 | (nodenum: &nodenum, config: (char)PNPMODE_STATIC, data: 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(objp: 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 | |
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 | |
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 | |
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 | |
505 | static int __init pnpbios_init(void) |
506 | { |
507 | int ret; |
508 | |
509 | if (pnpbios_disabled || dmi_check_system(list: 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(header: pnp_bios_install); |
529 | |
530 | /* read the node info */ |
531 | ret = pnp_bios_dev_node_info(data: &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(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 | |
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(x: &unload_sem); |
568 | task = kthread_run(pnp_dock_thread, NULL, "kpnpbiosd" ); |
569 | return PTR_ERR_OR_ZERO(ptr: task); |
570 | } |
571 | |
572 | /* Start the kernel thread later: */ |
573 | device_initcall(pnpbios_thread_init); |
574 | |
575 | EXPORT_SYMBOL(pnpbios_protocol); |
576 | |