xref: /openbmc/linux/drivers/pnp/pnpbios/core.c (revision fea88a0c) 
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 #ifdef CONFIG_HOTPLUG
95 
96 static struct completion unload_sem;
97 
98 /*
99  * (Much of this belongs in a shared routine somewhere)
100  */
101 static int pnp_dock_event(int dock, struct pnp_docking_station_info *info)
102 {
103 	char *argv[3], **envp, *buf, *scratch;
104 	int i = 0, value;
105 
106 	if (!(envp = kcalloc(20, sizeof(char *), GFP_KERNEL)))
107 		return -ENOMEM;
108 	if (!(buf = kzalloc(256, GFP_KERNEL))) {
109 		kfree(envp);
110 		return -ENOMEM;
111 	}
112 
113 	/* FIXME: if there are actual users of this, it should be
114 	 * integrated into the driver core and use the usual infrastructure
115 	 * like sysfs and uevents
116 	 */
117 	argv[0] = "/sbin/pnpbios";
118 	argv[1] = "dock";
119 	argv[2] = NULL;
120 
121 	/* minimal command environment */
122 	envp[i++] = "HOME=/";
123 	envp[i++] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin";
124 
125 #ifdef	DEBUG
126 	/* hint that policy agent should enter no-stdout debug mode */
127 	envp[i++] = "DEBUG=kernel";
128 #endif
129 	/* extensible set of named bus-specific parameters,
130 	 * supporting multiple driver selection algorithms.
131 	 */
132 	scratch = buf;
133 
134 	/* action:  add, remove */
135 	envp[i++] = scratch;
136 	scratch += sprintf(scratch, "ACTION=%s", dock ? "add" : "remove") + 1;
137 
138 	/* Report the ident for the dock */
139 	envp[i++] = scratch;
140 	scratch += sprintf(scratch, "DOCK=%x/%x/%x",
141 			   info->location_id, info->serial, info->capabilities);
142 	envp[i] = NULL;
143 
144 	value = call_usermodehelper(argv [0], argv, envp, UMH_WAIT_EXEC);
145 	kfree(buf);
146 	kfree(envp);
147 	return 0;
148 }
149 
150 /*
151  * Poll the PnP docking at regular intervals
152  */
153 static int pnp_dock_thread(void *unused)
154 {
155 	static struct pnp_docking_station_info now;
156 	int docked = -1, d = 0;
157 
158 	set_freezable();
159 	while (1) {
160 		int status;
161 
162 		/*
163 		 * Poll every 2 seconds
164 		 */
165 		msleep_interruptible(2000);
166 
167 		if (try_to_freeze())
168 			continue;
169 
170 		status = pnp_bios_dock_station_info(&now);
171 
172 		switch (status) {
173 			/*
174 			 * No dock to manage
175 			 */
176 		case PNP_FUNCTION_NOT_SUPPORTED:
177 			complete_and_exit(&unload_sem, 0);
178 		case PNP_SYSTEM_NOT_DOCKED:
179 			d = 0;
180 			break;
181 		case PNP_SUCCESS:
182 			d = 1;
183 			break;
184 		default:
185 			pnpbios_print_status("pnp_dock_thread", status);
186 			continue;
187 		}
188 		if (d != docked) {
189 			if (pnp_dock_event(d, &now) == 0) {
190 				docked = d;
191 #if 0
192 				printk(KERN_INFO
193 				       "PnPBIOS: Docking station %stached\n",
194 				       docked ? "at" : "de");
195 #endif
196 			}
197 		}
198 	}
199 	complete_and_exit(&unload_sem, 0);
200 }
201 
202 #endif				/* CONFIG_HOTPLUG */
203 
204 static int pnpbios_get_resources(struct pnp_dev *dev)
205 {
206 	u8 nodenum = dev->number;
207 	struct pnp_bios_node *node;
208 
209 	if (!pnpbios_is_dynamic(dev))
210 		return -EPERM;
211 
212 	pnp_dbg(&dev->dev, "get resources\n");
213 	node = kzalloc(node_info.max_node_size, GFP_KERNEL);
214 	if (!node)
215 		return -1;
216 	if (pnp_bios_get_dev_node(&nodenum, (char)PNPMODE_DYNAMIC, node)) {
217 		kfree(node);
218 		return -ENODEV;
219 	}
220 	pnpbios_read_resources_from_node(dev, node);
221 	dev->active = pnp_is_active(dev);
222 	kfree(node);
223 	return 0;
224 }
225 
226 static int pnpbios_set_resources(struct pnp_dev *dev)
227 {
228 	u8 nodenum = dev->number;
229 	struct pnp_bios_node *node;
230 	int ret;
231 
232 	if (!pnpbios_is_dynamic(dev))
233 		return -EPERM;
234 
235 	pnp_dbg(&dev->dev, "set resources\n");
236 	node = kzalloc(node_info.max_node_size, GFP_KERNEL);
237 	if (!node)
238 		return -1;
239 	if (pnp_bios_get_dev_node(&nodenum, (char)PNPMODE_DYNAMIC, node)) {
240 		kfree(node);
241 		return -ENODEV;
242 	}
243 	if (pnpbios_write_resources_to_node(dev, node) < 0) {
244 		kfree(node);
245 		return -1;
246 	}
247 	ret = pnp_bios_set_dev_node(node->handle, (char)PNPMODE_DYNAMIC, node);
248 	kfree(node);
249 	if (ret > 0)
250 		ret = -1;
251 	return ret;
252 }
253 
254 static void pnpbios_zero_data_stream(struct pnp_bios_node *node)
255 {
256 	unsigned char *p = (char *)node->data;
257 	unsigned char *end = (char *)(node->data + node->size);
258 	unsigned int len;
259 	int i;
260 
261 	while ((char *)p < (char *)end) {
262 		if (p[0] & 0x80) {	/* large tag */
263 			len = (p[2] << 8) | p[1];
264 			p += 3;
265 		} else {
266 			if (((p[0] >> 3) & 0x0f) == 0x0f)
267 				return;
268 			len = p[0] & 0x07;
269 			p += 1;
270 		}
271 		for (i = 0; i < len; i++)
272 			p[i] = 0;
273 		p += len;
274 	}
275 	printk(KERN_ERR
276 	       "PnPBIOS: Resource structure did not contain an end tag.\n");
277 }
278 
279 static int pnpbios_disable_resources(struct pnp_dev *dev)
280 {
281 	struct pnp_bios_node *node;
282 	u8 nodenum = dev->number;
283 	int ret;
284 
285 	if (dev->flags & PNPBIOS_NO_DISABLE || !pnpbios_is_dynamic(dev))
286 		return -EPERM;
287 
288 	node = kzalloc(node_info.max_node_size, GFP_KERNEL);
289 	if (!node)
290 		return -ENOMEM;
291 
292 	if (pnp_bios_get_dev_node(&nodenum, (char)PNPMODE_DYNAMIC, node)) {
293 		kfree(node);
294 		return -ENODEV;
295 	}
296 	pnpbios_zero_data_stream(node);
297 
298 	ret = pnp_bios_set_dev_node(dev->number, (char)PNPMODE_DYNAMIC, node);
299 	kfree(node);
300 	if (ret > 0)
301 		ret = -1;
302 	return ret;
303 }
304 
305 /* PnP Layer support */
306 
307 struct pnp_protocol pnpbios_protocol = {
308 	.name = "Plug and Play BIOS",
309 	.get = pnpbios_get_resources,
310 	.set = pnpbios_set_resources,
311 	.disable = pnpbios_disable_resources,
312 };
313 
314 static int __init insert_device(struct pnp_bios_node *node)
315 {
316 	struct list_head *pos;
317 	struct pnp_dev *dev;
318 	char id[8];
319 
320 	/* check if the device is already added */
321 	list_for_each(pos, &pnpbios_protocol.devices) {
322 		dev = list_entry(pos, struct pnp_dev, protocol_list);
323 		if (dev->number == node->handle)
324 			return -1;
325 	}
326 
327 	pnp_eisa_id_to_string(node->eisa_id & PNP_EISA_ID_MASK, id);
328 	dev = pnp_alloc_dev(&pnpbios_protocol, node->handle, id);
329 	if (!dev)
330 		return -1;
331 
332 	pnpbios_parse_data_stream(dev, node);
333 	dev->active = pnp_is_active(dev);
334 	dev->flags = node->flags;
335 	if (!(dev->flags & PNPBIOS_NO_CONFIG))
336 		dev->capabilities |= PNP_CONFIGURABLE;
337 	if (!(dev->flags & PNPBIOS_NO_DISABLE) && pnpbios_is_dynamic(dev))
338 		dev->capabilities |= PNP_DISABLE;
339 	dev->capabilities |= PNP_READ;
340 	if (pnpbios_is_dynamic(dev))
341 		dev->capabilities |= PNP_WRITE;
342 	if (dev->flags & PNPBIOS_REMOVABLE)
343 		dev->capabilities |= PNP_REMOVABLE;
344 
345 	/* clear out the damaged flags */
346 	if (!dev->active)
347 		pnp_init_resources(dev);
348 
349 	pnp_add_device(dev);
350 	pnpbios_interface_attach_device(node);
351 
352 	return 0;
353 }
354 
355 static void __init build_devlist(void)
356 {
357 	u8 nodenum;
358 	unsigned int nodes_got = 0;
359 	unsigned int devs = 0;
360 	struct pnp_bios_node *node;
361 
362 	node = kzalloc(node_info.max_node_size, GFP_KERNEL);
363 	if (!node)
364 		return;
365 
366 	for (nodenum = 0; nodenum < 0xff;) {
367 		u8 thisnodenum = nodenum;
368 		/* eventually we will want to use PNPMODE_STATIC here but for now
369 		 * dynamic will help us catch buggy bioses to add to the blacklist.
370 		 */
371 		if (!pnpbios_dont_use_current_config) {
372 			if (pnp_bios_get_dev_node
373 			    (&nodenum, (char)PNPMODE_DYNAMIC, node))
374 				break;
375 		} else {
376 			if (pnp_bios_get_dev_node
377 			    (&nodenum, (char)PNPMODE_STATIC, node))
378 				break;
379 		}
380 		nodes_got++;
381 		if (insert_device(node) == 0)
382 			devs++;
383 		if (nodenum <= thisnodenum) {
384 			printk(KERN_ERR
385 			       "PnPBIOS: build_devlist: Node number 0x%x is out of sequence following node 0x%x. Aborting.\n",
386 			       (unsigned int)nodenum,
387 			       (unsigned int)thisnodenum);
388 			break;
389 		}
390 	}
391 	kfree(node);
392 
393 	printk(KERN_INFO
394 	       "PnPBIOS: %i node%s reported by PnP BIOS; %i recorded by driver\n",
395 	       nodes_got, nodes_got != 1 ? "s" : "", devs);
396 }
397 
398 /*
399  *
400  * INIT AND EXIT
401  *
402  */
403 
404 static int pnpbios_disabled;
405 int pnpbios_dont_use_current_config;
406 
407 static int __init pnpbios_setup(char *str)
408 {
409 	int invert;
410 
411 	while ((str != NULL) && (*str != '\0')) {
412 		if (strncmp(str, "off", 3) == 0)
413 			pnpbios_disabled = 1;
414 		if (strncmp(str, "on", 2) == 0)
415 			pnpbios_disabled = 0;
416 		invert = (strncmp(str, "no-", 3) == 0);
417 		if (invert)
418 			str += 3;
419 		if (strncmp(str, "curr", 4) == 0)
420 			pnpbios_dont_use_current_config = invert;
421 		str = strchr(str, ',');
422 		if (str != NULL)
423 			str += strspn(str, ", \t");
424 	}
425 
426 	return 1;
427 }
428 
429 __setup("pnpbios=", pnpbios_setup);
430 
431 /* PnP BIOS signature: "$PnP" */
432 #define PNP_SIGNATURE   (('$' << 0) + ('P' << 8) + ('n' << 16) + ('P' << 24))
433 
434 static int __init pnpbios_probe_system(void)
435 {
436 	union pnp_bios_install_struct *check;
437 	u8 sum;
438 	int length, i;
439 
440 	printk(KERN_INFO "PnPBIOS: Scanning system for PnP BIOS support...\n");
441 
442 	/*
443 	 * Search the defined area (0xf0000-0xffff0) for a valid PnP BIOS
444 	 * structure and, if one is found, sets up the selectors and
445 	 * entry points
446 	 */
447 	for (check = (union pnp_bios_install_struct *)__va(0xf0000);
448 	     check < (union pnp_bios_install_struct *)__va(0xffff0);
449 	     check = (void *)check + 16) {
450 		if (check->fields.signature != PNP_SIGNATURE)
451 			continue;
452 		printk(KERN_INFO
453 		       "PnPBIOS: Found PnP BIOS installation structure at 0x%p\n",
454 		       check);
455 		length = check->fields.length;
456 		if (!length) {
457 			printk(KERN_ERR
458 			       "PnPBIOS: installation structure is invalid, skipping\n");
459 			continue;
460 		}
461 		for (sum = 0, i = 0; i < length; i++)
462 			sum += check->chars[i];
463 		if (sum) {
464 			printk(KERN_ERR
465 			       "PnPBIOS: installation structure is corrupted, skipping\n");
466 			continue;
467 		}
468 		if (check->fields.version < 0x10) {
469 			printk(KERN_WARNING
470 			       "PnPBIOS: PnP BIOS version %d.%d is not supported\n",
471 			       check->fields.version >> 4,
472 			       check->fields.version & 15);
473 			continue;
474 		}
475 		printk(KERN_INFO
476 		       "PnPBIOS: PnP BIOS version %d.%d, entry 0x%x:0x%x, dseg 0x%x\n",
477 		       check->fields.version >> 4, check->fields.version & 15,
478 		       check->fields.pm16cseg, check->fields.pm16offset,
479 		       check->fields.pm16dseg);
480 		pnp_bios_install = check;
481 		return 1;
482 	}
483 
484 	printk(KERN_INFO "PnPBIOS: PnP BIOS support was not detected.\n");
485 	return 0;
486 }
487 
488 static int __init exploding_pnp_bios(const struct dmi_system_id *d)
489 {
490 	printk(KERN_WARNING "%s detected. Disabling PnPBIOS\n", d->ident);
491 	return 0;
492 }
493 
494 static struct dmi_system_id pnpbios_dmi_table[] __initdata = {
495 	{			/* PnPBIOS GPF on boot */
496 	 .callback = exploding_pnp_bios,
497 	 .ident = "Higraded P14H",
498 	 .matches = {
499 		     DMI_MATCH(DMI_BIOS_VENDOR, "American Megatrends Inc."),
500 		     DMI_MATCH(DMI_BIOS_VERSION, "07.00T"),
501 		     DMI_MATCH(DMI_SYS_VENDOR, "Higraded"),
502 		     DMI_MATCH(DMI_PRODUCT_NAME, "P14H"),
503 		     },
504 	 },
505 	{			/* PnPBIOS GPF on boot */
506 	 .callback = exploding_pnp_bios,
507 	 .ident = "ASUS P4P800",
508 	 .matches = {
509 		     DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer Inc."),
510 		     DMI_MATCH(DMI_BOARD_NAME, "P4P800"),
511 		     },
512 	 },
513 	{}
514 };
515 
516 static int __init pnpbios_init(void)
517 {
518 	int ret;
519 
520 #if defined(CONFIG_PPC)
521 	if (check_legacy_ioport(PNPBIOS_BASE))
522 		return -ENODEV;
523 #endif
524 	if (pnpbios_disabled || dmi_check_system(pnpbios_dmi_table) ||
525 	    paravirt_enabled()) {
526 		printk(KERN_INFO "PnPBIOS: Disabled\n");
527 		return -ENODEV;
528 	}
529 #ifdef CONFIG_PNPACPI
530 	if (!acpi_disabled && !pnpacpi_disabled) {
531 		pnpbios_disabled = 1;
532 		printk(KERN_INFO "PnPBIOS: Disabled by ACPI PNP\n");
533 		return -ENODEV;
534 	}
535 #endif				/* CONFIG_ACPI */
536 
537 	/* scan the system for pnpbios support */
538 	if (!pnpbios_probe_system())
539 		return -ENODEV;
540 
541 	/* make preparations for bios calls */
542 	pnpbios_calls_init(pnp_bios_install);
543 
544 	/* read the node info */
545 	ret = pnp_bios_dev_node_info(&node_info);
546 	if (ret) {
547 		printk(KERN_ERR
548 		       "PnPBIOS: Unable to get node info.  Aborting.\n");
549 		return ret;
550 	}
551 
552 	/* register with the pnp layer */
553 	ret = pnp_register_protocol(&pnpbios_protocol);
554 	if (ret) {
555 		printk(KERN_ERR
556 		       "PnPBIOS: Unable to register driver.  Aborting.\n");
557 		return ret;
558 	}
559 
560 	/* start the proc interface */
561 	ret = pnpbios_proc_init();
562 	if (ret)
563 		printk(KERN_ERR "PnPBIOS: Failed to create proc interface.\n");
564 
565 	/* scan for pnpbios devices */
566 	build_devlist();
567 
568 	pnp_platform_devices = 1;
569 	return 0;
570 }
571 
572 fs_initcall(pnpbios_init);
573 
574 static int __init pnpbios_thread_init(void)
575 {
576 #if defined(CONFIG_PPC)
577 	if (check_legacy_ioport(PNPBIOS_BASE))
578 		return 0;
579 #endif
580 	if (pnpbios_disabled)
581 		return 0;
582 #ifdef CONFIG_HOTPLUG
583 	{
584 		struct task_struct *task;
585 		init_completion(&unload_sem);
586 		task = kthread_run(pnp_dock_thread, NULL, "kpnpbiosd");
587 		if (IS_ERR(task))
588 			return PTR_ERR(task);
589 	}
590 #endif
591 	return 0;
592 }
593 
594 /* Start the kernel thread later: */
595 module_init(pnpbios_thread_init);
596 
597 EXPORT_SYMBOL(pnpbios_protocol);
598