Freezer: make kernel threads nonfreezable by default
[safe/jmp/linux-2.6] / drivers / pnp / pnpbios / core.c
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/pnpbios.h>
54 #include <linux/device.h>
55 #include <linux/pnp.h>
56 #include <linux/mm.h>
57 #include <linux/smp.h>
58 #include <linux/slab.h>
59 #include <linux/completion.h>
60 #include <linux/spinlock.h>
61 #include <linux/dmi.h>
62 #include <linux/delay.h>
63 #include <linux/acpi.h>
64 #include <linux/freezer.h>
65 #include <linux/kthread.h>
66
67 #include <asm/page.h>
68 #include <asm/desc.h>
69 #include <asm/system.h>
70 #include <asm/byteorder.h>
71
72 #include "pnpbios.h"
73
74
75 /*
76  *
77  * PnP BIOS INTERFACE
78  *
79  */
80
81 static union pnp_bios_install_struct * pnp_bios_install = NULL;
82
83 int pnp_bios_present(void)
84 {
85         return (pnp_bios_install != NULL);
86 }
87
88 struct pnp_dev_node_info node_info;
89
90 /*
91  *
92  * DOCKING FUNCTIONS
93  *
94  */
95
96 #ifdef CONFIG_HOTPLUG
97
98 static int unloading = 0;
99 static struct completion unload_sem;
100
101 /*
102  * (Much of this belongs in a shared routine somewhere)
103  */
104  
105 static int pnp_dock_event(int dock, struct pnp_docking_station_info *info)
106 {
107         char *argv [3], **envp, *buf, *scratch;
108         int i = 0, value;
109
110         if (!current->fs->root) {
111                 return -EAGAIN;
112         }
113         if (!(envp = kcalloc(20, sizeof (char *), GFP_KERNEL))) {
114                 return -ENOMEM;
115         }
116         if (!(buf = kzalloc(256, GFP_KERNEL))) {
117                 kfree (envp);
118                 return -ENOMEM;
119         }
120
121         /* FIXME: if there are actual users of this, it should be integrated into
122          * the driver core and use the usual infrastructure like sysfs and uevents */
123         argv [0] = "/sbin/pnpbios";
124         argv [1] = "dock";
125         argv [2] = NULL;
126
127         /* minimal command environment */
128         envp [i++] = "HOME=/";
129         envp [i++] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin";
130
131 #ifdef  DEBUG
132         /* hint that policy agent should enter no-stdout debug mode */
133         envp [i++] = "DEBUG=kernel";
134 #endif
135         /* extensible set of named bus-specific parameters,
136          * supporting multiple driver selection algorithms.
137          */
138         scratch = buf;
139
140         /* action:  add, remove */
141         envp [i++] = scratch;
142         scratch += sprintf (scratch, "ACTION=%s", dock?"add":"remove") + 1;
143
144         /* Report the ident for the dock */
145         envp [i++] = scratch;
146         scratch += sprintf (scratch, "DOCK=%x/%x/%x",
147                 info->location_id, info->serial, info->capabilities);
148         envp[i] = NULL;
149         
150         value = call_usermodehelper (argv [0], argv, envp, 0);
151         kfree (buf);
152         kfree (envp);
153         return 0;
154 }
155
156 /*
157  * Poll the PnP docking at regular intervals
158  */
159 static int pnp_dock_thread(void * unused)
160 {
161         static struct pnp_docking_station_info now;
162         int docked = -1, d = 0;
163         set_freezable();
164         while (!unloading)
165         {
166                 int status;
167                 
168                 /*
169                  * Poll every 2 seconds
170                  */
171                 msleep_interruptible(2000);
172
173                 if (try_to_freeze())
174                         continue;
175
176                 status = pnp_bios_dock_station_info(&now);
177
178                 switch(status)
179                 {
180                         /*
181                          * No dock to manage
182                          */
183                         case PNP_FUNCTION_NOT_SUPPORTED:
184                                 complete_and_exit(&unload_sem, 0);
185                         case PNP_SYSTEM_NOT_DOCKED:
186                                 d = 0;
187                                 break;
188                         case PNP_SUCCESS:
189                                 d = 1;
190                                 break;
191                         default:
192                                 pnpbios_print_status( "pnp_dock_thread", status );
193                                 continue;
194                 }
195                 if(d != docked)
196                 {
197                         if(pnp_dock_event(d, &now)==0)
198                         {
199                                 docked = d;
200 #if 0
201                                 printk(KERN_INFO "PnPBIOS: Docking station %stached\n", docked?"at":"de");
202 #endif
203                         }
204                 }
205         }
206         complete_and_exit(&unload_sem, 0);
207 }
208
209 #endif   /* CONFIG_HOTPLUG */
210
211 static int pnpbios_get_resources(struct pnp_dev * dev, struct pnp_resource_table * res)
212 {
213         u8 nodenum = dev->number;
214         struct pnp_bios_node * node;
215
216         /* just in case */
217         if(!pnpbios_is_dynamic(dev))
218                 return -EPERM;
219
220         node = kzalloc(node_info.max_node_size, GFP_KERNEL);
221         if (!node)
222                 return -1;
223         if (pnp_bios_get_dev_node(&nodenum, (char )PNPMODE_DYNAMIC, node)) {
224                 kfree(node);
225                 return -ENODEV;
226         }
227         pnpbios_read_resources_from_node(res, node);
228         dev->active = pnp_is_active(dev);
229         kfree(node);
230         return 0;
231 }
232
233 static int pnpbios_set_resources(struct pnp_dev * dev, struct pnp_resource_table * res)
234 {
235         u8 nodenum = dev->number;
236         struct pnp_bios_node * node;
237         int ret;
238
239         /* just in case */
240         if (!pnpbios_is_dynamic(dev))
241                 return -EPERM;
242
243         node = kzalloc(node_info.max_node_size, GFP_KERNEL);
244         if (!node)
245                 return -1;
246         if (pnp_bios_get_dev_node(&nodenum, (char )PNPMODE_DYNAMIC, node)) {
247                 kfree(node);
248                 return -ENODEV;
249         }
250         if(pnpbios_write_resources_to_node(res, node)<0) {
251                 kfree(node);
252                 return -1;
253         }
254         ret = pnp_bios_set_dev_node(node->handle, (char)PNPMODE_DYNAMIC, node);
255         kfree(node);
256         if (ret > 0)
257                 ret = -1;
258         return ret;
259 }
260
261 static void pnpbios_zero_data_stream(struct pnp_bios_node * node)
262 {
263         unsigned char * p = (char *)node->data;
264         unsigned char * end = (char *)(node->data + node->size);
265         unsigned int len;
266         int i;
267         while ((char *)p < (char *)end) {
268                 if(p[0] & 0x80) { /* large tag */
269                         len = (p[2] << 8) | p[1];
270                         p += 3;
271                 } else {
272                         if (((p[0]>>3) & 0x0f) == 0x0f)
273                                 return;
274                         len = p[0] & 0x07;
275                         p += 1;
276                 }
277                 for (i = 0; i < len; i++)
278                         p[i] = 0;
279                 p += len;
280         }
281         printk(KERN_ERR "PnPBIOS: Resource structure did not contain an end tag.\n");
282 }
283
284 static int pnpbios_disable_resources(struct pnp_dev *dev)
285 {
286         struct pnp_bios_node * node;
287         u8 nodenum = dev->number;
288         int ret;
289
290         /* just in case */
291         if(dev->flags & PNPBIOS_NO_DISABLE || !pnpbios_is_dynamic(dev))
292                 return -EPERM;
293
294         node = kzalloc(node_info.max_node_size, GFP_KERNEL);
295         if (!node)
296                 return -ENOMEM;
297
298         if (pnp_bios_get_dev_node(&nodenum, (char )PNPMODE_DYNAMIC, node)) {
299                 kfree(node);
300                 return -ENODEV;
301         }
302         pnpbios_zero_data_stream(node);
303
304         ret = pnp_bios_set_dev_node(dev->number, (char)PNPMODE_DYNAMIC, node);
305         kfree(node);
306         if (ret > 0)
307                 ret = -1;
308         return ret;
309 }
310
311 /* PnP Layer support */
312
313 struct pnp_protocol pnpbios_protocol = {
314         .name   = "Plug and Play BIOS",
315         .get    = pnpbios_get_resources,
316         .set    = pnpbios_set_resources,
317         .disable = pnpbios_disable_resources,
318 };
319
320 static int insert_device(struct pnp_dev *dev, struct pnp_bios_node * node)
321 {
322         struct list_head * pos;
323         struct pnp_dev * pnp_dev;
324         struct pnp_id *dev_id;
325         char id[8];
326
327         /* check if the device is already added */
328         dev->number = node->handle;
329         list_for_each (pos, &pnpbios_protocol.devices){
330                 pnp_dev = list_entry(pos, struct pnp_dev, protocol_list);
331                 if (dev->number == pnp_dev->number)
332                         return -1;
333         }
334
335         /* set the initial values for the PnP device */
336         dev_id = kzalloc(sizeof(struct pnp_id), GFP_KERNEL);
337         if (!dev_id)
338                 return -1;
339         pnpid32_to_pnpid(node->eisa_id,id);
340         memcpy(dev_id->id,id,7);
341         pnp_add_id(dev_id, dev);
342         pnpbios_parse_data_stream(dev, node);
343         dev->active = pnp_is_active(dev);
344         dev->flags = node->flags;
345         if (!(dev->flags & PNPBIOS_NO_CONFIG))
346                 dev->capabilities |= PNP_CONFIGURABLE;
347         if (!(dev->flags & PNPBIOS_NO_DISABLE) && pnpbios_is_dynamic(dev))
348                 dev->capabilities |= PNP_DISABLE;
349         dev->capabilities |= PNP_READ;
350         if (pnpbios_is_dynamic(dev))
351                 dev->capabilities |= PNP_WRITE;
352         if (dev->flags & PNPBIOS_REMOVABLE)
353                 dev->capabilities |= PNP_REMOVABLE;
354         dev->protocol = &pnpbios_protocol;
355
356         /* clear out the damaged flags */
357         if (!dev->active)
358                 pnp_init_resource_table(&dev->res);
359
360         pnp_add_device(dev);
361         pnpbios_interface_attach_device(node);
362
363         return 0;
364 }
365
366 static void __init build_devlist(void)
367 {
368         u8 nodenum;
369         unsigned int nodes_got = 0;
370         unsigned int devs = 0;
371         struct pnp_bios_node *node;
372         struct pnp_dev *dev;
373
374         node = kzalloc(node_info.max_node_size, GFP_KERNEL);
375         if (!node)
376                 return;
377
378         for(nodenum=0; nodenum<0xff; ) {
379                 u8 thisnodenum = nodenum;
380                 /* eventually we will want to use PNPMODE_STATIC here but for now
381                  * dynamic will help us catch buggy bioses to add to the blacklist.
382                  */
383                 if (!pnpbios_dont_use_current_config) {
384                         if (pnp_bios_get_dev_node(&nodenum, (char )PNPMODE_DYNAMIC, node))
385                                 break;
386                 } else {
387                         if (pnp_bios_get_dev_node(&nodenum, (char )PNPMODE_STATIC, node))
388                                 break;
389                 }
390                 nodes_got++;
391                 dev =  kzalloc(sizeof (struct pnp_dev), GFP_KERNEL);
392                 if (!dev)
393                         break;
394                 if(insert_device(dev,node)<0)
395                         kfree(dev);
396                 else
397                         devs++;
398                 if (nodenum <= thisnodenum) {
399                         printk(KERN_ERR "PnPBIOS: build_devlist: Node number 0x%x is out of sequence following node 0x%x. Aborting.\n", (unsigned int)nodenum, (unsigned int)thisnodenum);
400                         break;
401                 }
402         }
403         kfree(node);
404
405         printk(KERN_INFO "PnPBIOS: %i node%s reported by PnP BIOS; %i recorded by driver\n",
406                 nodes_got, nodes_got != 1 ? "s" : "", devs);
407 }
408
409 /*
410  *
411  * INIT AND EXIT
412  *
413  */
414
415 static int pnpbios_disabled; /* = 0 */
416 int pnpbios_dont_use_current_config; /* = 0 */
417
418 #ifndef MODULE
419 static int __init pnpbios_setup(char *str)
420 {
421         int invert;
422
423         while ((str != NULL) && (*str != '\0')) {
424                 if (strncmp(str, "off", 3) == 0)
425                         pnpbios_disabled=1;
426                 if (strncmp(str, "on", 2) == 0)
427                         pnpbios_disabled=0;
428                 invert = (strncmp(str, "no-", 3) == 0);
429                 if (invert)
430                         str += 3;
431                 if (strncmp(str, "curr", 4) == 0)
432                         pnpbios_dont_use_current_config = invert;
433                 str = strchr(str, ',');
434                 if (str != NULL)
435                         str += strspn(str, ", \t");
436         }
437
438         return 1;
439 }
440
441 __setup("pnpbios=", pnpbios_setup);
442 #endif
443
444 /* PnP BIOS signature: "$PnP" */
445 #define PNP_SIGNATURE   (('$' << 0) + ('P' << 8) + ('n' << 16) + ('P' << 24))
446
447 static int __init pnpbios_probe_system(void)
448 {
449         union pnp_bios_install_struct *check;
450         u8 sum;
451         int length, i;
452
453         printk(KERN_INFO "PnPBIOS: Scanning system for PnP BIOS support...\n");
454
455         /*
456          * Search the defined area (0xf0000-0xffff0) for a valid PnP BIOS
457          * structure and, if one is found, sets up the selectors and
458          * entry points
459          */
460         for (check = (union pnp_bios_install_struct *) __va(0xf0000);
461              check < (union pnp_bios_install_struct *) __va(0xffff0);
462              check = (void *)check + 16) {
463                 if (check->fields.signature != PNP_SIGNATURE)
464                         continue;
465                 printk(KERN_INFO "PnPBIOS: Found PnP BIOS installation structure at 0x%p\n", check);
466                 length = check->fields.length;
467                 if (!length) {
468                         printk(KERN_ERR "PnPBIOS: installation structure is invalid, skipping\n");
469                         continue;
470                 }
471                 for (sum = 0, i = 0; i < length; i++)
472                         sum += check->chars[i];
473                 if (sum) {
474                         printk(KERN_ERR "PnPBIOS: installation structure is corrupted, skipping\n");
475                         continue;
476                 }
477                 if (check->fields.version < 0x10) {
478                         printk(KERN_WARNING "PnPBIOS: PnP BIOS version %d.%d is not supported\n",
479                                check->fields.version >> 4,
480                                check->fields.version & 15);
481                         continue;
482                 }
483                 printk(KERN_INFO "PnPBIOS: PnP BIOS version %d.%d, entry 0x%x:0x%x, dseg 0x%x\n",
484                        check->fields.version >> 4, check->fields.version & 15,
485                        check->fields.pm16cseg, check->fields.pm16offset,
486                        check->fields.pm16dseg);
487                 pnp_bios_install = check;
488                 return 1;
489         }
490
491         printk(KERN_INFO "PnPBIOS: PnP BIOS support was not detected.\n");
492         return 0;
493 }
494
495 static int __init exploding_pnp_bios(struct dmi_system_id *d)
496 {
497         printk(KERN_WARNING "%s detected. Disabling PnPBIOS\n", d->ident);
498         return 0;
499 }
500
501 static struct dmi_system_id pnpbios_dmi_table[] __initdata = {
502         {       /* PnPBIOS GPF on boot */
503                 .callback = exploding_pnp_bios,
504                 .ident = "Higraded P14H",
505                 .matches = {
506                         DMI_MATCH(DMI_BIOS_VENDOR, "American Megatrends Inc."),
507                         DMI_MATCH(DMI_BIOS_VERSION, "07.00T"),
508                         DMI_MATCH(DMI_SYS_VENDOR, "Higraded"),
509                         DMI_MATCH(DMI_PRODUCT_NAME, "P14H"),
510                 },
511         },
512         {       /* PnPBIOS GPF on boot */
513                 .callback = exploding_pnp_bios,
514                 .ident = "ASUS P4P800",
515                 .matches = {
516                         DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer Inc."),
517                         DMI_MATCH(DMI_BOARD_NAME, "P4P800"),
518                 },
519         },
520         { }
521 };
522
523 static int __init pnpbios_init(void)
524 {
525         int ret;
526
527 #if defined(CONFIG_PPC_MERGE)
528         if (check_legacy_ioport(PNPBIOS_BASE))
529                 return -ENODEV;
530 #endif
531         if (pnpbios_disabled || dmi_check_system(pnpbios_dmi_table) ||
532             paravirt_enabled()) {
533                 printk(KERN_INFO "PnPBIOS: Disabled\n");
534                 return -ENODEV;
535         }
536
537 #ifdef CONFIG_PNPACPI
538         if (!acpi_disabled && !pnpacpi_disabled) {
539                 pnpbios_disabled = 1;
540                 printk(KERN_INFO "PnPBIOS: Disabled by ACPI PNP\n");
541                 return -ENODEV;
542         }
543 #endif /* CONFIG_ACPI */
544
545         /* scan the system for pnpbios support */
546         if (!pnpbios_probe_system())
547                 return -ENODEV;
548
549         /* make preparations for bios calls */
550         pnpbios_calls_init(pnp_bios_install);
551
552         /* read the node info */
553         ret = pnp_bios_dev_node_info(&node_info);
554         if (ret) {
555                 printk(KERN_ERR "PnPBIOS: Unable to get node info.  Aborting.\n");
556                 return ret;
557         }
558
559         /* register with the pnp layer */
560         ret = pnp_register_protocol(&pnpbios_protocol);
561         if (ret) {
562                 printk(KERN_ERR "PnPBIOS: Unable to register driver.  Aborting.\n");
563                 return ret;
564         }
565
566         /* start the proc interface */
567         ret = pnpbios_proc_init();
568         if (ret)
569                 printk(KERN_ERR "PnPBIOS: Failed to create proc interface.\n");
570
571         /* scan for pnpbios devices */
572         build_devlist();
573
574         pnp_platform_devices = 1;
575         return 0;
576 }
577
578 subsys_initcall(pnpbios_init);
579
580 static int __init pnpbios_thread_init(void)
581 {
582         struct task_struct *task;
583 #if defined(CONFIG_PPC_MERGE)
584         if (check_legacy_ioport(PNPBIOS_BASE))
585                 return 0;
586 #endif
587         if (pnpbios_disabled)
588                 return 0;
589 #ifdef CONFIG_HOTPLUG
590         init_completion(&unload_sem);
591         task = kthread_run(pnp_dock_thread, NULL, "kpnpbiosd");
592         if (!IS_ERR(task))
593                 unloading = 0;
594 #endif
595         return 0;
596 }
597
598 #ifndef MODULE
599
600 /* init/main.c calls pnpbios_init early */
601
602 /* Start the kernel thread later: */
603 module_init(pnpbios_thread_init);
604
605 #else
606
607 /*
608  * N.B.: Building pnpbios as a module hasn't been fully implemented
609  */
610
611 MODULE_LICENSE("GPL");
612
613 static int __init pnpbios_init_all(void)
614 {
615         int r;
616
617         r = pnpbios_init();
618         if (r)
619                 return r;
620         r = pnpbios_thread_init();
621         if (r)
622                 return r;
623         return 0;
624 }
625
626 static void __exit pnpbios_exit(void)
627 {
628 #ifdef CONFIG_HOTPLUG
629         unloading = 1;
630         wait_for_completion(&unload_sem);
631 #endif
632         pnpbios_proc_exit();
633         /* We ought to free resources here */
634         return;
635 }
636
637 module_init(pnpbios_init_all);
638 module_exit(pnpbios_exit);
639
640 #endif
641
642 EXPORT_SYMBOL(pnpbios_protocol);