drivers/pnp/pnpbios/core.c

   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(20, sizeof(char *), GFP_KERNEL)))
  93                 return -ENOMEM;
  94         if (!(buf = kzalloc(256, GFP_KERNEL))) {
  95                 kfree(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(scratch, "ACTION=%s", dock ? "add" : "remove") + 1;
 123
 124         /* Report the ident for the dock */
 125         envp[i++] = scratch;
 126         scratch += sprintf(scratch, "DOCK=%x/%x/%x",
 127                            info->location_id, info->serial, info->capabilities);
 128         envp[i] = NULL;
 129
 130         value = call_usermodehelper(sbin_pnpbios, argv, envp, UMH_WAIT_EXEC);
 131         kfree(buf);
 132         kfree(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(2000);
 152
 153                 if (try_to_freeze())
 154                         continue;
 155
 156                 status = pnp_bios_dock_station_info(&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("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(d, &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(node_info.max_node_size, GFP_KERNEL);
 199         if (!node)
 200                 return -1;
 201         if (pnp_bios_get_dev_node(&nodenum, (char)PNPMODE_DYNAMIC, node)) {
 202                 kfree(node);
 203                 return -ENODEV;
 204         }
 205         pnpbios_read_resources_from_node(dev, node);
 206         dev->active = pnp_is_active(dev);
 207         kfree(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(node_info.max_node_size, GFP_KERNEL);
 222         if (!node)
 223                 return -1;
 224         if (pnp_bios_get_dev_node(&nodenum, (char)PNPMODE_DYNAMIC, node)) {
 225                 kfree(node);
 226                 return -ENODEV;
 227         }
 228         if (pnpbios_write_resources_to_node(dev, node) < 0) {
 229                 kfree(node);
 230                 return -1;
 231         }
 232         ret = pnp_bios_set_dev_node(node->handle, (char)PNPMODE_DYNAMIC, node);
 233         kfree(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(node_info.max_node_size, GFP_KERNEL);
 274         if (!node)
 275                 return -ENOMEM;
 276
 277         if (pnp_bios_get_dev_node(&nodenum, (char)PNPMODE_DYNAMIC, node)) {
 278                 kfree(node);
 279                 return -ENODEV;
 280         }
 281         pnpbios_zero_data_stream(node);
 282
 283         ret = pnp_bios_set_dev_node(dev->number, (char)PNPMODE_DYNAMIC, node);
 284         kfree(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(node->eisa_id & PNP_EISA_ID_MASK, id);
 312         dev = pnp_alloc_dev(&pnpbios_protocol, node->handle, 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);
 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(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, (char)PNPMODE_DYNAMIC, node))
 363                                 break;
 364                 } else {
 365                         if (pnp_bios_get_dev_node
 366                             (&nodenum, (char)PNPMODE_STATIC, 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(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(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(pnp_bios_install);
 529
 530         /* read the node info */
 531         ret = pnp_bios_dev_node_info(&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(&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(&unload_sem);
 568         task = kthread_run(pnp_dock_thread, NULL, "kpnpbiosd");
 569         return PTR_ERR_OR_ZERO(task);
 570 }
 571
 572 /* Start the kernel thread later: */
 573 device_initcall(pnpbios_thread_init);
 574
 575 EXPORT_SYMBOL(pnpbios_protocol);