xref: /openbmc/linux/drivers/pnp/pnpbios/core.c (revision 6ee73861) 
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/system.h>
69 #include <asm/byteorder.h>
70 
71 #include "../base.h"
72 #include "pnpbios.h"
73 
74 /*
75  *
76  * PnP BIOS INTERFACE
77  *
78  */
79 
80 static union pnp_bios_install_struct *pnp_bios_install = NULL;
81 
82 int pnp_bios_present(void)
83 {
84 	return (pnp_bios_install != NULL);
85 }
86 
87 struct pnp_dev_node_info node_info;
88 
89 /*
90  *
91  * DOCKING FUNCTIONS
92  *
93  */
94 
95 #ifdef CONFIG_HOTPLUG
96 
97 static struct completion unload_sem;
98 
99 /*
100  * (Much of this belongs in a shared routine somewhere)
101  */
102 static int pnp_dock_event(int dock, struct pnp_docking_station_info *info)
103 {
104 	char *argv[3], **envp, *buf, *scratch;
105 	int i = 0, value;
106 
107 	if (!(envp = kcalloc(20, sizeof(char *), GFP_KERNEL)))
108 		return -ENOMEM;
109 	if (!(buf = kzalloc(256, GFP_KERNEL))) {
110 		kfree(envp);
111 		return -ENOMEM;
112 	}
113 
114 	/* FIXME: if there are actual users of this, it should be
115 	 * integrated into the driver core and use the usual infrastructure
116 	 * like sysfs and uevents
117 	 */
118 	argv[0] = "/sbin/pnpbios";
119 	argv[1] = "dock";
120 	argv[2] = NULL;
121 
122 	/* minimal command environment */
123 	envp[i++] = "HOME=/";
124 	envp[i++] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin";
125 
126 #ifdef	DEBUG
127 	/* hint that policy agent should enter no-stdout debug mode */
128 	envp[i++] = "DEBUG=kernel";
129 #endif
130 	/* extensible set of named bus-specific parameters,
131 	 * supporting multiple driver selection algorithms.
132 	 */
133 	scratch = buf;
134 
135 	/* action:  add, remove */
136 	envp[i++] = scratch;
137 	scratch += sprintf(scratch, "ACTION=%s", dock ? "add" : "remove") + 1;
138 
139 	/* Report the ident for the dock */
140 	envp[i++] = scratch;
141 	scratch += sprintf(scratch, "DOCK=%x/%x/%x",
142 			   info->location_id, info->serial, info->capabilities);
143 	envp[i] = NULL;
144 
145 	value = call_usermodehelper(argv [0], argv, envp, UMH_WAIT_EXEC);
146 	kfree(buf);
147 	kfree(envp);
148 	return 0;
149 }
150 
151 /*
152  * Poll the PnP docking at regular intervals
153  */
154 static int pnp_dock_thread(void *unused)
155 {
156 	static struct pnp_docking_station_info now;
157 	int docked = -1, d = 0;
158 
159 	set_freezable();
160 	while (1) {
161 		int status;
162 
163 		/*
164 		 * Poll every 2 seconds
165 		 */
166 		msleep_interruptible(2000);
167 
168 		if (try_to_freeze())
169 			continue;
170 
171 		status = pnp_bios_dock_station_info(&now);
172 
173 		switch (status) {
174 			/*
175 			 * No dock to manage
176 			 */
177 		case PNP_FUNCTION_NOT_SUPPORTED:
178 			complete_and_exit(&unload_sem, 0);
179 		case PNP_SYSTEM_NOT_DOCKED:
180 			d = 0;
181 			break;
182 		case PNP_SUCCESS:
183 			d = 1;
184 			break;
185 		default:
186 			pnpbios_print_status("pnp_dock_thread", status);
187 			continue;
188 		}
189 		if (d != docked) {
190 			if (pnp_dock_event(d, &now) == 0) {
191 				docked = d;
192 #if 0
193 				printk(KERN_INFO
194 				       "PnPBIOS: Docking station %stached\n",
195 				       docked ? "at" : "de");
196 #endif
197 			}
198 		}
199 	}
200 	complete_and_exit(&unload_sem, 0);
201 }
202 
203 #endif				/* CONFIG_HOTPLUG */
204 
205 static int pnpbios_get_resources(struct pnp_dev *dev)
206 {
207 	u8 nodenum = dev->number;
208 	struct pnp_bios_node *node;
209 
210 	if (!pnpbios_is_dynamic(dev))
211 		return -EPERM;
212 
213 	pnp_dbg(&dev->dev, "get resources\n");
214 	node = kzalloc(node_info.max_node_size, GFP_KERNEL);
215 	if (!node)
216 		return -1;
217 	if (pnp_bios_get_dev_node(&nodenum, (char)PNPMODE_DYNAMIC, node)) {
218 		kfree(node);
219 		return -ENODEV;
220 	}
221 	pnpbios_read_resources_from_node(dev, node);
222 	dev->active = pnp_is_active(dev);
223 	kfree(node);
224 	return 0;
225 }
226 
227 static int pnpbios_set_resources(struct pnp_dev *dev)
228 {
229 	u8 nodenum = dev->number;
230 	struct pnp_bios_node *node;
231 	int ret;
232 
233 	if (!pnpbios_is_dynamic(dev))
234 		return -EPERM;
235 
236 	pnp_dbg(&dev->dev, "set resources\n");
237 	node = kzalloc(node_info.max_node_size, GFP_KERNEL);
238 	if (!node)
239 		return -1;
240 	if (pnp_bios_get_dev_node(&nodenum, (char)PNPMODE_DYNAMIC, node)) {
241 		kfree(node);
242 		return -ENODEV;
243 	}
244 	if (pnpbios_write_resources_to_node(dev, node) < 0) {
245 		kfree(node);
246 		return -1;
247 	}
248 	ret = pnp_bios_set_dev_node(node->handle, (char)PNPMODE_DYNAMIC, node);
249 	kfree(node);
250 	if (ret > 0)
251 		ret = -1;
252 	return ret;
253 }
254 
255 static void pnpbios_zero_data_stream(struct pnp_bios_node *node)
256 {
257 	unsigned char *p = (char *)node->data;
258 	unsigned char *end = (char *)(node->data + node->size);
259 	unsigned int len;
260 	int i;
261 
262 	while ((char *)p < (char *)end) {
263 		if (p[0] & 0x80) {	/* large tag */
264 			len = (p[2] << 8) | p[1];
265 			p += 3;
266 		} else {
267 			if (((p[0] >> 3) & 0x0f) == 0x0f)
268 				return;
269 			len = p[0] & 0x07;
270 			p += 1;
271 		}
272 		for (i = 0; i < len; i++)
273 			p[i] = 0;
274 		p += len;
275 	}
276 	printk(KERN_ERR
277 	       "PnPBIOS: Resource structure did not contain an end tag.\n");
278 }
279 
280 static int pnpbios_disable_resources(struct pnp_dev *dev)
281 {
282 	struct pnp_bios_node *node;
283 	u8 nodenum = dev->number;
284 	int ret;
285 
286 	if (dev->flags & PNPBIOS_NO_DISABLE || !pnpbios_is_dynamic(dev))
287 		return -EPERM;
288 
289 	node = kzalloc(node_info.max_node_size, GFP_KERNEL);
290 	if (!node)
291 		return -ENOMEM;
292 
293 	if (pnp_bios_get_dev_node(&nodenum, (char)PNPMODE_DYNAMIC, node)) {
294 		kfree(node);
295 		return -ENODEV;
296 	}
297 	pnpbios_zero_data_stream(node);
298 
299 	ret = pnp_bios_set_dev_node(dev->number, (char)PNPMODE_DYNAMIC, node);
300 	kfree(node);
301 	if (ret > 0)
302 		ret = -1;
303 	return ret;
304 }
305 
306 /* PnP Layer support */
307 
308 struct pnp_protocol pnpbios_protocol = {
309 	.name = "Plug and Play BIOS",
310 	.get = pnpbios_get_resources,
311 	.set = pnpbios_set_resources,
312 	.disable = pnpbios_disable_resources,
313 };
314 
315 static int __init insert_device(struct pnp_bios_node *node)
316 {
317 	struct list_head *pos;
318 	struct pnp_dev *dev;
319 	char id[8];
320 
321 	/* check if the device is already added */
322 	list_for_each(pos, &pnpbios_protocol.devices) {
323 		dev = list_entry(pos, struct pnp_dev, protocol_list);
324 		if (dev->number == node->handle)
325 			return -1;
326 	}
327 
328 	pnp_eisa_id_to_string(node->eisa_id & PNP_EISA_ID_MASK, id);
329 	dev = pnp_alloc_dev(&pnpbios_protocol, node->handle, id);
330 	if (!dev)
331 		return -1;
332 
333 	pnpbios_parse_data_stream(dev, node);
334 	dev->active = pnp_is_active(dev);
335 	dev->flags = node->flags;
336 	if (!(dev->flags & PNPBIOS_NO_CONFIG))
337 		dev->capabilities |= PNP_CONFIGURABLE;
338 	if (!(dev->flags & PNPBIOS_NO_DISABLE) && pnpbios_is_dynamic(dev))
339 		dev->capabilities |= PNP_DISABLE;
340 	dev->capabilities |= PNP_READ;
341 	if (pnpbios_is_dynamic(dev))
342 		dev->capabilities |= PNP_WRITE;
343 	if (dev->flags & PNPBIOS_REMOVABLE)
344 		dev->capabilities |= PNP_REMOVABLE;
345 
346 	/* clear out the damaged flags */
347 	if (!dev->active)
348 		pnp_init_resources(dev);
349 
350 	pnp_add_device(dev);
351 	pnpbios_interface_attach_device(node);
352 
353 	return 0;
354 }
355 
356 static void __init build_devlist(void)
357 {
358 	u8 nodenum;
359 	unsigned int nodes_got = 0;
360 	unsigned int devs = 0;
361 	struct pnp_bios_node *node;
362 
363 	node = kzalloc(node_info.max_node_size, GFP_KERNEL);
364 	if (!node)
365 		return;
366 
367 	for (nodenum = 0; nodenum < 0xff;) {
368 		u8 thisnodenum = nodenum;
369 		/* eventually we will want to use PNPMODE_STATIC here but for now
370 		 * dynamic will help us catch buggy bioses to add to the blacklist.
371 		 */
372 		if (!pnpbios_dont_use_current_config) {
373 			if (pnp_bios_get_dev_node
374 			    (&nodenum, (char)PNPMODE_DYNAMIC, node))
375 				break;
376 		} else {
377 			if (pnp_bios_get_dev_node
378 			    (&nodenum, (char)PNPMODE_STATIC, node))
379 				break;
380 		}
381 		nodes_got++;
382 		if (insert_device(node) == 0)
383 			devs++;
384 		if (nodenum <= thisnodenum) {
385 			printk(KERN_ERR
386 			       "PnPBIOS: build_devlist: Node number 0x%x is out of sequence following node 0x%x. Aborting.\n",
387 			       (unsigned int)nodenum,
388 			       (unsigned int)thisnodenum);
389 			break;
390 		}
391 	}
392 	kfree(node);
393 
394 	printk(KERN_INFO
395 	       "PnPBIOS: %i node%s reported by PnP BIOS; %i recorded by driver\n",
396 	       nodes_got, nodes_got != 1 ? "s" : "", devs);
397 }
398 
399 /*
400  *
401  * INIT AND EXIT
402  *
403  */
404 
405 static int pnpbios_disabled;
406 int pnpbios_dont_use_current_config;
407 
408 static int __init pnpbios_setup(char *str)
409 {
410 	int invert;
411 
412 	while ((str != NULL) && (*str != '\0')) {
413 		if (strncmp(str, "off", 3) == 0)
414 			pnpbios_disabled = 1;
415 		if (strncmp(str, "on", 2) == 0)
416 			pnpbios_disabled = 0;
417 		invert = (strncmp(str, "no-", 3) == 0);
418 		if (invert)
419 			str += 3;
420 		if (strncmp(str, "curr", 4) == 0)
421 			pnpbios_dont_use_current_config = invert;
422 		str = strchr(str, ',');
423 		if (str != NULL)
424 			str += strspn(str, ", \t");
425 	}
426 
427 	return 1;
428 }
429 
430 __setup("pnpbios=", pnpbios_setup);
431 
432 /* PnP BIOS signature: "$PnP" */
433 #define PNP_SIGNATURE   (('$' << 0) + ('P' << 8) + ('n' << 16) + ('P' << 24))
434 
435 static int __init pnpbios_probe_system(void)
436 {
437 	union pnp_bios_install_struct *check;
438 	u8 sum;
439 	int length, i;
440 
441 	printk(KERN_INFO "PnPBIOS: Scanning system for PnP BIOS support...\n");
442 
443 	/*
444 	 * Search the defined area (0xf0000-0xffff0) for a valid PnP BIOS
445 	 * structure and, if one is found, sets up the selectors and
446 	 * entry points
447 	 */
448 	for (check = (union pnp_bios_install_struct *)__va(0xf0000);
449 	     check < (union pnp_bios_install_struct *)__va(0xffff0);
450 	     check = (void *)check + 16) {
451 		if (check->fields.signature != PNP_SIGNATURE)
452 			continue;
453 		printk(KERN_INFO
454 		       "PnPBIOS: Found PnP BIOS installation structure at 0x%p\n",
455 		       check);
456 		length = check->fields.length;
457 		if (!length) {
458 			printk(KERN_ERR
459 			       "PnPBIOS: installation structure is invalid, skipping\n");
460 			continue;
461 		}
462 		for (sum = 0, i = 0; i < length; i++)
463 			sum += check->chars[i];
464 		if (sum) {
465 			printk(KERN_ERR
466 			       "PnPBIOS: installation structure is corrupted, skipping\n");
467 			continue;
468 		}
469 		if (check->fields.version < 0x10) {
470 			printk(KERN_WARNING
471 			       "PnPBIOS: PnP BIOS version %d.%d is not supported\n",
472 			       check->fields.version >> 4,
473 			       check->fields.version & 15);
474 			continue;
475 		}
476 		printk(KERN_INFO
477 		       "PnPBIOS: PnP BIOS version %d.%d, entry 0x%x:0x%x, dseg 0x%x\n",
478 		       check->fields.version >> 4, check->fields.version & 15,
479 		       check->fields.pm16cseg, check->fields.pm16offset,
480 		       check->fields.pm16dseg);
481 		pnp_bios_install = check;
482 		return 1;
483 	}
484 
485 	printk(KERN_INFO "PnPBIOS: PnP BIOS support was not detected.\n");
486 	return 0;
487 }
488 
489 static int __init exploding_pnp_bios(const struct dmi_system_id *d)
490 {
491 	printk(KERN_WARNING "%s detected. Disabling PnPBIOS\n", d->ident);
492 	return 0;
493 }
494 
495 static struct dmi_system_id pnpbios_dmi_table[] __initdata = {
496 	{			/* PnPBIOS GPF on boot */
497 	 .callback = exploding_pnp_bios,
498 	 .ident = "Higraded P14H",
499 	 .matches = {
500 		     DMI_MATCH(DMI_BIOS_VENDOR, "American Megatrends Inc."),
501 		     DMI_MATCH(DMI_BIOS_VERSION, "07.00T"),
502 		     DMI_MATCH(DMI_SYS_VENDOR, "Higraded"),
503 		     DMI_MATCH(DMI_PRODUCT_NAME, "P14H"),
504 		     },
505 	 },
506 	{			/* PnPBIOS GPF on boot */
507 	 .callback = exploding_pnp_bios,
508 	 .ident = "ASUS P4P800",
509 	 .matches = {
510 		     DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer Inc."),
511 		     DMI_MATCH(DMI_BOARD_NAME, "P4P800"),
512 		     },
513 	 },
514 	{}
515 };
516 
517 static int __init pnpbios_init(void)
518 {
519 	int ret;
520 
521 #if defined(CONFIG_PPC)
522 	if (check_legacy_ioport(PNPBIOS_BASE))
523 		return -ENODEV;
524 #endif
525 	if (pnpbios_disabled || dmi_check_system(pnpbios_dmi_table) ||
526 	    paravirt_enabled()) {
527 		printk(KERN_INFO "PnPBIOS: Disabled\n");
528 		return -ENODEV;
529 	}
530 #ifdef CONFIG_PNPACPI
531 	if (!acpi_disabled && !pnpacpi_disabled) {
532 		pnpbios_disabled = 1;
533 		printk(KERN_INFO "PnPBIOS: Disabled by ACPI PNP\n");
534 		return -ENODEV;
535 	}
536 #endif				/* CONFIG_ACPI */
537 
538 	/* scan the system for pnpbios support */
539 	if (!pnpbios_probe_system())
540 		return -ENODEV;
541 
542 	/* make preparations for bios calls */
543 	pnpbios_calls_init(pnp_bios_install);
544 
545 	/* read the node info */
546 	ret = pnp_bios_dev_node_info(&node_info);
547 	if (ret) {
548 		printk(KERN_ERR
549 		       "PnPBIOS: Unable to get node info.  Aborting.\n");
550 		return ret;
551 	}
552 
553 	/* register with the pnp layer */
554 	ret = pnp_register_protocol(&pnpbios_protocol);
555 	if (ret) {
556 		printk(KERN_ERR
557 		       "PnPBIOS: Unable to register driver.  Aborting.\n");
558 		return ret;
559 	}
560 
561 	/* start the proc interface */
562 	ret = pnpbios_proc_init();
563 	if (ret)
564 		printk(KERN_ERR "PnPBIOS: Failed to create proc interface.\n");
565 
566 	/* scan for pnpbios devices */
567 	build_devlist();
568 
569 	pnp_platform_devices = 1;
570 	return 0;
571 }
572 
573 fs_initcall(pnpbios_init);
574 
575 static int __init pnpbios_thread_init(void)
576 {
577 #if defined(CONFIG_PPC)
578 	if (check_legacy_ioport(PNPBIOS_BASE))
579 		return 0;
580 #endif
581 	if (pnpbios_disabled)
582 		return 0;
583 #ifdef CONFIG_HOTPLUG
584 	{
585 		struct task_struct *task;
586 		init_completion(&unload_sem);
587 		task = kthread_run(pnp_dock_thread, NULL, "kpnpbiosd");
588 		if (IS_ERR(task))
589 			return PTR_ERR(task);
590 	}
591 #endif
592 	return 0;
593 }
594 
595 /* Start the kernel thread later: */
596 module_init(pnpbios_thread_init);
597 
598 EXPORT_SYMBOL(pnpbios_protocol);
599