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); 576