xref: /openbmc/linux/drivers/pnp/pnpbios/core.c (revision d0b73b48) 
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/byteorder.h>
69 
70 #include "../base.h"
71 #include "pnpbios.h"
72 
73 /*
74  *
75  * PnP BIOS INTERFACE
76  *
77  */
78 
79 static union pnp_bios_install_struct *pnp_bios_install = NULL;
80 
81 int pnp_bios_present(void)
82 {
83 	return (pnp_bios_install != NULL);
84 }
85 
86 struct pnp_dev_node_info node_info;
87 
88 /*
89  *
90  * DOCKING FUNCTIONS
91  *
92  */
93 
94 static struct completion unload_sem;
95 
96 /*
97  * (Much of this belongs in a shared routine somewhere)
98  */
99 static int pnp_dock_event(int dock, struct pnp_docking_station_info *info)
100 {
101 	char *argv[3], **envp, *buf, *scratch;
102 	int i = 0, value;
103 
104 	if (!(envp = kcalloc(20, sizeof(char *), GFP_KERNEL)))
105 		return -ENOMEM;
106 	if (!(buf = kzalloc(256, GFP_KERNEL))) {
107 		kfree(envp);
108 		return -ENOMEM;
109 	}
110 
111 	/* FIXME: if there are actual users of this, it should be
112 	 * integrated into the driver core and use the usual infrastructure
113 	 * like sysfs and uevents
114 	 */
115 	argv[0] = "/sbin/pnpbios";
116 	argv[1] = "dock";
117 	argv[2] = NULL;
118 
119 	/* minimal command environment */
120 	envp[i++] = "HOME=/";
121 	envp[i++] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin";
122 
123 #ifdef	DEBUG
124 	/* hint that policy agent should enter no-stdout debug mode */
125 	envp[i++] = "DEBUG=kernel";
126 #endif
127 	/* extensible set of named bus-specific parameters,
128 	 * supporting multiple driver selection algorithms.
129 	 */
130 	scratch = buf;
131 
132 	/* action:  add, remove */
133 	envp[i++] = scratch;
134 	scratch += sprintf(scratch, "ACTION=%s", dock ? "add" : "remove") + 1;
135 
136 	/* Report the ident for the dock */
137 	envp[i++] = scratch;
138 	scratch += sprintf(scratch, "DOCK=%x/%x/%x",
139 			   info->location_id, info->serial, info->capabilities);
140 	envp[i] = NULL;
141 
142 	value = call_usermodehelper(argv [0], argv, envp, UMH_WAIT_EXEC);
143 	kfree(buf);
144 	kfree(envp);
145 	return 0;
146 }
147 
148 /*
149  * Poll the PnP docking at regular intervals
150  */
151 static int pnp_dock_thread(void *unused)
152 {
153 	static struct pnp_docking_station_info now;
154 	int docked = -1, d = 0;
155 
156 	set_freezable();
157 	while (1) {
158 		int status;
159 
160 		/*
161 		 * Poll every 2 seconds
162 		 */
163 		msleep_interruptible(2000);
164 
165 		if (try_to_freeze())
166 			continue;
167 
168 		status = pnp_bios_dock_station_info(&now);
169 
170 		switch (status) {
171 			/*
172 			 * No dock to manage
173 			 */
174 		case PNP_FUNCTION_NOT_SUPPORTED:
175 			complete_and_exit(&unload_sem, 0);
176 		case PNP_SYSTEM_NOT_DOCKED:
177 			d = 0;
178 			break;
179 		case PNP_SUCCESS:
180 			d = 1;
181 			break;
182 		default:
183 			pnpbios_print_status("pnp_dock_thread", status);
184 			continue;
185 		}
186 		if (d != docked) {
187 			if (pnp_dock_event(d, &now) == 0) {
188 				docked = d;
189 #if 0
190 				printk(KERN_INFO
191 				       "PnPBIOS: Docking station %stached\n",
192 				       docked ? "at" : "de");
193 #endif
194 			}
195 		}
196 	}
197 	complete_and_exit(&unload_sem, 0);
198 }
199 
200 static int pnpbios_get_resources(struct pnp_dev *dev)
201 {
202 	u8 nodenum = dev->number;
203 	struct pnp_bios_node *node;
204 
205 	if (!pnpbios_is_dynamic(dev))
206 		return -EPERM;
207 
208 	pnp_dbg(&dev->dev, "get resources\n");
209 	node = kzalloc(node_info.max_node_size, GFP_KERNEL);
210 	if (!node)
211 		return -1;
212 	if (pnp_bios_get_dev_node(&nodenum, (char)PNPMODE_DYNAMIC, node)) {
213 		kfree(node);
214 		return -ENODEV;
215 	}
216 	pnpbios_read_resources_from_node(dev, node);
217 	dev->active = pnp_is_active(dev);
218 	kfree(node);
219 	return 0;
220 }
221 
222 static int pnpbios_set_resources(struct pnp_dev *dev)
223 {
224 	u8 nodenum = dev->number;
225 	struct pnp_bios_node *node;
226 	int ret;
227 
228 	if (!pnpbios_is_dynamic(dev))
229 		return -EPERM;
230 
231 	pnp_dbg(&dev->dev, "set resources\n");
232 	node = kzalloc(node_info.max_node_size, GFP_KERNEL);
233 	if (!node)
234 		return -1;
235 	if (pnp_bios_get_dev_node(&nodenum, (char)PNPMODE_DYNAMIC, node)) {
236 		kfree(node);
237 		return -ENODEV;
238 	}
239 	if (pnpbios_write_resources_to_node(dev, node) < 0) {
240 		kfree(node);
241 		return -1;
242 	}
243 	ret = pnp_bios_set_dev_node(node->handle, (char)PNPMODE_DYNAMIC, node);
244 	kfree(node);
245 	if (ret > 0)
246 		ret = -1;
247 	return ret;
248 }
249 
250 static void pnpbios_zero_data_stream(struct pnp_bios_node *node)
251 {
252 	unsigned char *p = (char *)node->data;
253 	unsigned char *end = (char *)(node->data + node->size);
254 	unsigned int len;
255 	int i;
256 
257 	while ((char *)p < (char *)end) {
258 		if (p[0] & 0x80) {	/* large tag */
259 			len = (p[2] << 8) | p[1];
260 			p += 3;
261 		} else {
262 			if (((p[0] >> 3) & 0x0f) == 0x0f)
263 				return;
264 			len = p[0] & 0x07;
265 			p += 1;
266 		}
267 		for (i = 0; i < len; i++)
268 			p[i] = 0;
269 		p += len;
270 	}
271 	printk(KERN_ERR
272 	       "PnPBIOS: Resource structure did not contain an end tag.\n");
273 }
274 
275 static int pnpbios_disable_resources(struct pnp_dev *dev)
276 {
277 	struct pnp_bios_node *node;
278 	u8 nodenum = dev->number;
279 	int ret;
280 
281 	if (dev->flags & PNPBIOS_NO_DISABLE || !pnpbios_is_dynamic(dev))
282 		return -EPERM;
283 
284 	node = kzalloc(node_info.max_node_size, GFP_KERNEL);
285 	if (!node)
286 		return -ENOMEM;
287 
288 	if (pnp_bios_get_dev_node(&nodenum, (char)PNPMODE_DYNAMIC, node)) {
289 		kfree(node);
290 		return -ENODEV;
291 	}
292 	pnpbios_zero_data_stream(node);
293 
294 	ret = pnp_bios_set_dev_node(dev->number, (char)PNPMODE_DYNAMIC, node);
295 	kfree(node);
296 	if (ret > 0)
297 		ret = -1;
298 	return ret;
299 }
300 
301 /* PnP Layer support */
302 
303 struct pnp_protocol pnpbios_protocol = {
304 	.name = "Plug and Play BIOS",
305 	.get = pnpbios_get_resources,
306 	.set = pnpbios_set_resources,
307 	.disable = pnpbios_disable_resources,
308 };
309 
310 static int __init insert_device(struct pnp_bios_node *node)
311 {
312 	struct list_head *pos;
313 	struct pnp_dev *dev;
314 	char id[8];
315 
316 	/* check if the device is already added */
317 	list_for_each(pos, &pnpbios_protocol.devices) {
318 		dev = list_entry(pos, struct pnp_dev, protocol_list);
319 		if (dev->number == node->handle)
320 			return -1;
321 	}
322 
323 	pnp_eisa_id_to_string(node->eisa_id & PNP_EISA_ID_MASK, id);
324 	dev = pnp_alloc_dev(&pnpbios_protocol, node->handle, id);
325 	if (!dev)
326 		return -1;
327 
328 	pnpbios_parse_data_stream(dev, node);
329 	dev->active = pnp_is_active(dev);
330 	dev->flags = node->flags;
331 	if (!(dev->flags & PNPBIOS_NO_CONFIG))
332 		dev->capabilities |= PNP_CONFIGURABLE;
333 	if (!(dev->flags & PNPBIOS_NO_DISABLE) && pnpbios_is_dynamic(dev))
334 		dev->capabilities |= PNP_DISABLE;
335 	dev->capabilities |= PNP_READ;
336 	if (pnpbios_is_dynamic(dev))
337 		dev->capabilities |= PNP_WRITE;
338 	if (dev->flags & PNPBIOS_REMOVABLE)
339 		dev->capabilities |= PNP_REMOVABLE;
340 
341 	/* clear out the damaged flags */
342 	if (!dev->active)
343 		pnp_init_resources(dev);
344 
345 	pnp_add_device(dev);
346 	pnpbios_interface_attach_device(node);
347 
348 	return 0;
349 }
350 
351 static void __init build_devlist(void)
352 {
353 	u8 nodenum;
354 	unsigned int nodes_got = 0;
355 	unsigned int devs = 0;
356 	struct pnp_bios_node *node;
357 
358 	node = kzalloc(node_info.max_node_size, GFP_KERNEL);
359 	if (!node)
360 		return;
361 
362 	for (nodenum = 0; nodenum < 0xff;) {
363 		u8 thisnodenum = nodenum;
364 		/* eventually we will want to use PNPMODE_STATIC here but for now
365 		 * dynamic will help us catch buggy bioses to add to the blacklist.
366 		 */
367 		if (!pnpbios_dont_use_current_config) {
368 			if (pnp_bios_get_dev_node
369 			    (&nodenum, (char)PNPMODE_DYNAMIC, node))
370 				break;
371 		} else {
372 			if (pnp_bios_get_dev_node
373 			    (&nodenum, (char)PNPMODE_STATIC, node))
374 				break;
375 		}
376 		nodes_got++;
377 		if (insert_device(node) == 0)
378 			devs++;
379 		if (nodenum <= thisnodenum) {
380 			printk(KERN_ERR
381 			       "PnPBIOS: build_devlist: Node number 0x%x is out of sequence following node 0x%x. Aborting.\n",
382 			       (unsigned int)nodenum,
383 			       (unsigned int)thisnodenum);
384 			break;
385 		}
386 	}
387 	kfree(node);
388 
389 	printk(KERN_INFO
390 	       "PnPBIOS: %i node%s reported by PnP BIOS; %i recorded by driver\n",
391 	       nodes_got, nodes_got != 1 ? "s" : "", devs);
392 }
393 
394 /*
395  *
396  * INIT AND EXIT
397  *
398  */
399 
400 static int pnpbios_disabled;
401 int pnpbios_dont_use_current_config;
402 
403 static int __init pnpbios_setup(char *str)
404 {
405 	int invert;
406 
407 	while ((str != NULL) && (*str != '\0')) {
408 		if (strncmp(str, "off", 3) == 0)
409 			pnpbios_disabled = 1;
410 		if (strncmp(str, "on", 2) == 0)
411 			pnpbios_disabled = 0;
412 		invert = (strncmp(str, "no-", 3) == 0);
413 		if (invert)
414 			str += 3;
415 		if (strncmp(str, "curr", 4) == 0)
416 			pnpbios_dont_use_current_config = invert;
417 		str = strchr(str, ',');
418 		if (str != NULL)
419 			str += strspn(str, ", \t");
420 	}
421 
422 	return 1;
423 }
424 
425 __setup("pnpbios=", pnpbios_setup);
426 
427 /* PnP BIOS signature: "$PnP" */
428 #define PNP_SIGNATURE   (('$' << 0) + ('P' << 8) + ('n' << 16) + ('P' << 24))
429 
430 static int __init pnpbios_probe_system(void)
431 {
432 	union pnp_bios_install_struct *check;
433 	u8 sum;
434 	int length, i;
435 
436 	printk(KERN_INFO "PnPBIOS: Scanning system for PnP BIOS support...\n");
437 
438 	/*
439 	 * Search the defined area (0xf0000-0xffff0) for a valid PnP BIOS
440 	 * structure and, if one is found, sets up the selectors and
441 	 * entry points
442 	 */
443 	for (check = (union pnp_bios_install_struct *)__va(0xf0000);
444 	     check < (union pnp_bios_install_struct *)__va(0xffff0);
445 	     check = (void *)check + 16) {
446 		if (check->fields.signature != PNP_SIGNATURE)
447 			continue;
448 		printk(KERN_INFO
449 		       "PnPBIOS: Found PnP BIOS installation structure at 0x%p\n",
450 		       check);
451 		length = check->fields.length;
452 		if (!length) {
453 			printk(KERN_ERR
454 			       "PnPBIOS: installation structure is invalid, skipping\n");
455 			continue;
456 		}
457 		for (sum = 0, i = 0; i < length; i++)
458 			sum += check->chars[i];
459 		if (sum) {
460 			printk(KERN_ERR
461 			       "PnPBIOS: installation structure is corrupted, skipping\n");
462 			continue;
463 		}
464 		if (check->fields.version < 0x10) {
465 			printk(KERN_WARNING
466 			       "PnPBIOS: PnP BIOS version %d.%d is not supported\n",
467 			       check->fields.version >> 4,
468 			       check->fields.version & 15);
469 			continue;
470 		}
471 		printk(KERN_INFO
472 		       "PnPBIOS: PnP BIOS version %d.%d, entry 0x%x:0x%x, dseg 0x%x\n",
473 		       check->fields.version >> 4, check->fields.version & 15,
474 		       check->fields.pm16cseg, check->fields.pm16offset,
475 		       check->fields.pm16dseg);
476 		pnp_bios_install = check;
477 		return 1;
478 	}
479 
480 	printk(KERN_INFO "PnPBIOS: PnP BIOS support was not detected.\n");
481 	return 0;
482 }
483 
484 static int __init exploding_pnp_bios(const struct dmi_system_id *d)
485 {
486 	printk(KERN_WARNING "%s detected. Disabling PnPBIOS\n", d->ident);
487 	return 0;
488 }
489 
490 static struct dmi_system_id pnpbios_dmi_table[] __initdata = {
491 	{			/* PnPBIOS GPF on boot */
492 	 .callback = exploding_pnp_bios,
493 	 .ident = "Higraded P14H",
494 	 .matches = {
495 		     DMI_MATCH(DMI_BIOS_VENDOR, "American Megatrends Inc."),
496 		     DMI_MATCH(DMI_BIOS_VERSION, "07.00T"),
497 		     DMI_MATCH(DMI_SYS_VENDOR, "Higraded"),
498 		     DMI_MATCH(DMI_PRODUCT_NAME, "P14H"),
499 		     },
500 	 },
501 	{			/* PnPBIOS GPF on boot */
502 	 .callback = exploding_pnp_bios,
503 	 .ident = "ASUS P4P800",
504 	 .matches = {
505 		     DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer Inc."),
506 		     DMI_MATCH(DMI_BOARD_NAME, "P4P800"),
507 		     },
508 	 },
509 	{}
510 };
511 
512 static int __init pnpbios_init(void)
513 {
514 	int ret;
515 
516 #if defined(CONFIG_PPC)
517 	if (check_legacy_ioport(PNPBIOS_BASE))
518 		return -ENODEV;
519 #endif
520 	if (pnpbios_disabled || dmi_check_system(pnpbios_dmi_table) ||
521 	    paravirt_enabled()) {
522 		printk(KERN_INFO "PnPBIOS: Disabled\n");
523 		return -ENODEV;
524 	}
525 #ifdef CONFIG_PNPACPI
526 	if (!acpi_disabled && !pnpacpi_disabled) {
527 		pnpbios_disabled = 1;
528 		printk(KERN_INFO "PnPBIOS: Disabled by ACPI PNP\n");
529 		return -ENODEV;
530 	}
531 #endif				/* CONFIG_ACPI */
532 
533 	/* scan the system for pnpbios support */
534 	if (!pnpbios_probe_system())
535 		return -ENODEV;
536 
537 	/* make preparations for bios calls */
538 	pnpbios_calls_init(pnp_bios_install);
539 
540 	/* read the node info */
541 	ret = pnp_bios_dev_node_info(&node_info);
542 	if (ret) {
543 		printk(KERN_ERR
544 		       "PnPBIOS: Unable to get node info.  Aborting.\n");
545 		return ret;
546 	}
547 
548 	/* register with the pnp layer */
549 	ret = pnp_register_protocol(&pnpbios_protocol);
550 	if (ret) {
551 		printk(KERN_ERR
552 		       "PnPBIOS: Unable to register driver.  Aborting.\n");
553 		return ret;
554 	}
555 
556 	/* start the proc interface */
557 	ret = pnpbios_proc_init();
558 	if (ret)
559 		printk(KERN_ERR "PnPBIOS: Failed to create proc interface.\n");
560 
561 	/* scan for pnpbios devices */
562 	build_devlist();
563 
564 	pnp_platform_devices = 1;
565 	return 0;
566 }
567 
568 fs_initcall(pnpbios_init);
569 
570 static int __init pnpbios_thread_init(void)
571 {
572 	struct task_struct *task;
573 #if defined(CONFIG_PPC)
574 	if (check_legacy_ioport(PNPBIOS_BASE))
575 		return 0;
576 #endif
577 	if (pnpbios_disabled)
578 		return 0;
579 
580 	init_completion(&unload_sem);
581 	task = kthread_run(pnp_dock_thread, NULL, "kpnpbiosd");
582 	if (IS_ERR(task))
583 		return PTR_ERR(task);
584 
585 	return 0;
586 }
587 
588 /* Start the kernel thread later: */
589 module_init(pnpbios_thread_init);
590 
591 EXPORT_SYMBOL(pnpbios_protocol);
592