linux/drivers/pnp/pnpbios/core.c
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   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
  66static union pnp_bios_install_struct *pnp_bios_install = NULL;
  67
  68int pnp_bios_present(void)
  69{
  70        return (pnp_bios_install != NULL);
  71}
  72
  73struct pnp_dev_node_info node_info;
  74
  75/*
  76 *
  77 * DOCKING FUNCTIONS
  78 *
  79 */
  80
  81static struct completion unload_sem;
  82
  83/*
  84 * (Much of this belongs in a shared routine somewhere)
  85 */
  86static 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 */
 139static 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                        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                        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        complete_and_exit(&unload_sem, 0);
 187}
 188
 189static 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
 211static 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
 239static 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
 264static 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
 292struct 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
 299static 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
 344static 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
 393static int pnpbios_disabled;
 394int pnpbios_dont_use_current_config;
 395
 396static 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
 423static 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
 477static 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
 483static 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
 505static 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
 558fs_initcall(pnpbios_init);
 559
 560static 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: */
 573device_initcall(pnpbios_thread_init);
 574
 575EXPORT_SYMBOL(pnpbios_protocol);
 576