pnp/pnpbios/core.c

0001 // SPDX-License-Identifier: GPL-2.0-or-later
0002 /*
0003  * pnpbios -- PnP BIOS driver
0004  *
0005  * This driver provides access to Plug-'n'-Play services provided by
0006  * the PnP BIOS firmware, described in the following documents:
0007  *   Plug and Play BIOS Specification, Version 1.0A, 5 May 1994
0008  *   Plug and Play BIOS Clarification Paper, 6 October 1994
0009  *     Compaq Computer Corporation, Phoenix Technologies Ltd., Intel Corp.
0010  *
0011  * Originally (C) 1998 Christian Schmidt <schmidt@digadd.de>
0012  * Modifications (C) 1998 Tom Lees <tom@lpsg.demon.co.uk>
0013  * Minor reorganizations by David Hinds <dahinds@users.sourceforge.net>
0014  * Further modifications (C) 2001, 2002 by:
0015  *   Alan Cox <alan@redhat.com>
0016  *   Thomas Hood
0017  *   Brian Gerst <bgerst@didntduck.org>
0018  *
0019  * Ported to the PnP Layer and several additional improvements (C) 2002
0020  * by Adam Belay <ambx1@neo.rr.com>
0021  */
0022
0023 /* Change Log
0024  *
0025  * Adam Belay - <ambx1@neo.rr.com> - March 16, 2003
0026  * rev 1.01 Only call pnp_bios_dev_node_info once
0027  *      Added pnpbios_print_status
0028  *      Added several new error messages and info messages
0029  *      Added pnpbios_interface_attach_device
0030  *      integrated core and proc init system
0031  *      Introduced PNPMODE flags
0032  *      Removed some useless includes
0033  */
0034
0035 #include <linux/types.h>
0036 #include <linux/init.h>
0037 #include <linux/linkage.h>
0038 #include <linux/kernel.h>
0039 #include <linux/device.h>
0040 #include <linux/pnp.h>
0041 #include <linux/mm.h>
0042 #include <linux/smp.h>
0043 #include <linux/slab.h>
0044 #include <linux/completion.h>
0045 #include <linux/spinlock.h>
0046 #include <linux/dmi.h>
0047 #include <linux/delay.h>
0048 #include <linux/acpi.h>
0049 #include <linux/freezer.h>
0050 #include <linux/kmod.h>
0051 #include <linux/kthread.h>
0052
0053 #include <asm/page.h>
0054 #include <asm/desc.h>
0055 #include <asm/byteorder.h>
0056
0057 #include "../base.h"
0058 #include "pnpbios.h"
0059
0060 /*
0061  *
0062  * PnP BIOS INTERFACE
0063  *
0064  */
0065
0066 static union pnp_bios_install_struct *pnp_bios_install = NULL;
0067
0068 int pnp_bios_present(void)
0069 {
0070     return (pnp_bios_install != NULL);
0071 }
0072
0073 struct pnp_dev_node_info node_info;
0074
0075 /*
0076  *
0077  * DOCKING FUNCTIONS
0078  *
0079  */
0080
0081 static struct completion unload_sem;
0082
0083 /*
0084  * (Much of this belongs in a shared routine somewhere)
0085  */
0086 static int pnp_dock_event(int dock, struct pnp_docking_station_info *info)
0087 {
0088     static char const sbin_pnpbios[] = "/sbin/pnpbios";
0089     char *argv[3], **envp, *buf, *scratch;
0090     int i = 0, value;
0091
0092     if (!(envp = kcalloc(20, sizeof(char *), GFP_KERNEL)))
0093         return -ENOMEM;
0094     if (!(buf = kzalloc(256, GFP_KERNEL))) {
0095         kfree(envp);
0096         return -ENOMEM;
0097     }
0098
0099     /* FIXME: if there are actual users of this, it should be
0100      * integrated into the driver core and use the usual infrastructure
0101      * like sysfs and uevents
0102      */
0103     argv[0] = (char *)sbin_pnpbios;
0104     argv[1] = "dock";
0105     argv[2] = NULL;
0106
0107     /* minimal command environment */
0108     envp[i++] = "HOME=/";
0109     envp[i++] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin";
0110
0111 #ifdef  DEBUG
0112     /* hint that policy agent should enter no-stdout debug mode */
0113     envp[i++] = "DEBUG=kernel";
0114 #endif
0115     /* extensible set of named bus-specific parameters,
0116      * supporting multiple driver selection algorithms.
0117      */
0118     scratch = buf;
0119
0120     /* action:  add, remove */
0121     envp[i++] = scratch;
0122     scratch += sprintf(scratch, "ACTION=%s", dock ? "add" : "remove") + 1;
0123
0124     /* Report the ident for the dock */
0125     envp[i++] = scratch;
0126     scratch += sprintf(scratch, "DOCK=%x/%x/%x",
0127                info->location_id, info->serial, info->capabilities);
0128     envp[i] = NULL;
0129
0130     value = call_usermodehelper(sbin_pnpbios, argv, envp, UMH_WAIT_EXEC);
0131     kfree(buf);
0132     kfree(envp);
0133     return 0;
0134 }
0135
0136 /*
0137  * Poll the PnP docking at regular intervals
0138  */
0139 static int pnp_dock_thread(void *unused)
0140 {
0141     static struct pnp_docking_station_info now;
0142     int docked = -1, d = 0;
0143
0144     set_freezable();
0145     while (1) {
0146         int status;
0147
0148         /*
0149          * Poll every 2 seconds
0150          */
0151         msleep_interruptible(2000);
0152
0153         if (try_to_freeze())
0154             continue;
0155
0156         status = pnp_bios_dock_station_info(&now);
0157
0158         switch (status) {
0159             /*
0160              * No dock to manage
0161              */
0162         case PNP_FUNCTION_NOT_SUPPORTED:
0163             kthread_complete_and_exit(&unload_sem, 0);
0164         case PNP_SYSTEM_NOT_DOCKED:
0165             d = 0;
0166             break;
0167         case PNP_SUCCESS:
0168             d = 1;
0169             break;
0170         default:
0171             pnpbios_print_status("pnp_dock_thread", status);
0172             printk(KERN_WARNING "PnPBIOS: disabling dock monitoring.\n");
0173             kthread_complete_and_exit(&unload_sem, 0);
0174         }
0175         if (d != docked) {
0176             if (pnp_dock_event(d, &now) == 0) {
0177                 docked = d;
0178 #if 0
0179                 printk(KERN_INFO
0180                        "PnPBIOS: Docking station %stached\n",
0181                        docked ? "at" : "de");
0182 #endif
0183             }
0184         }
0185     }
0186     kthread_complete_and_exit(&unload_sem, 0);
0187 }
0188
0189 static int pnpbios_get_resources(struct pnp_dev *dev)
0190 {
0191     u8 nodenum = dev->number;
0192     struct pnp_bios_node *node;
0193
0194     if (!pnpbios_is_dynamic(dev))
0195         return -EPERM;
0196
0197     pnp_dbg(&dev->dev, "get resources\n");
0198     node = kzalloc(node_info.max_node_size, GFP_KERNEL);
0199     if (!node)
0200         return -1;
0201     if (pnp_bios_get_dev_node(&nodenum, (char)PNPMODE_DYNAMIC, node)) {
0202         kfree(node);
0203         return -ENODEV;
0204     }
0205     pnpbios_read_resources_from_node(dev, node);
0206     dev->active = pnp_is_active(dev);
0207     kfree(node);
0208     return 0;
0209 }
0210
0211 static int pnpbios_set_resources(struct pnp_dev *dev)
0212 {
0213     u8 nodenum = dev->number;
0214     struct pnp_bios_node *node;
0215     int ret;
0216
0217     if (!pnpbios_is_dynamic(dev))
0218         return -EPERM;
0219
0220     pnp_dbg(&dev->dev, "set resources\n");
0221     node = kzalloc(node_info.max_node_size, GFP_KERNEL);
0222     if (!node)
0223         return -1;
0224     if (pnp_bios_get_dev_node(&nodenum, (char)PNPMODE_DYNAMIC, node)) {
0225         kfree(node);
0226         return -ENODEV;
0227     }
0228     if (pnpbios_write_resources_to_node(dev, node) < 0) {
0229         kfree(node);
0230         return -1;
0231     }
0232     ret = pnp_bios_set_dev_node(node->handle, (char)PNPMODE_DYNAMIC, node);
0233     kfree(node);
0234     if (ret > 0)
0235         ret = -1;
0236     return ret;
0237 }
0238
0239 static void pnpbios_zero_data_stream(struct pnp_bios_node *node)
0240 {
0241     unsigned char *p = (char *)node->data;
0242     unsigned char *end = (char *)(node->data + node->size);
0243     unsigned int len;
0244     int i;
0245
0246     while ((char *)p < (char *)end) {
0247         if (p[0] & 0x80) {  /* large tag */
0248             len = (p[2] << 8) | p[1];
0249             p += 3;
0250         } else {
0251             if (((p[0] >> 3) & 0x0f) == 0x0f)
0252                 return;
0253             len = p[0] & 0x07;
0254             p += 1;
0255         }
0256         for (i = 0; i < len; i++)
0257             p[i] = 0;
0258         p += len;
0259     }
0260     printk(KERN_ERR
0261            "PnPBIOS: Resource structure did not contain an end tag.\n");
0262 }
0263
0264 static int pnpbios_disable_resources(struct pnp_dev *dev)
0265 {
0266     struct pnp_bios_node *node;
0267     u8 nodenum = dev->number;
0268     int ret;
0269
0270     if (dev->flags & PNPBIOS_NO_DISABLE || !pnpbios_is_dynamic(dev))
0271         return -EPERM;
0272
0273     node = kzalloc(node_info.max_node_size, GFP_KERNEL);
0274     if (!node)
0275         return -ENOMEM;
0276
0277     if (pnp_bios_get_dev_node(&nodenum, (char)PNPMODE_DYNAMIC, node)) {
0278         kfree(node);
0279         return -ENODEV;
0280     }
0281     pnpbios_zero_data_stream(node);
0282
0283     ret = pnp_bios_set_dev_node(dev->number, (char)PNPMODE_DYNAMIC, node);
0284     kfree(node);
0285     if (ret > 0)
0286         ret = -1;
0287     return ret;
0288 }
0289
0290 /* PnP Layer support */
0291
0292 struct pnp_protocol pnpbios_protocol = {
0293     .name = "Plug and Play BIOS",
0294     .get = pnpbios_get_resources,
0295     .set = pnpbios_set_resources,
0296     .disable = pnpbios_disable_resources,
0297 };
0298
0299 static int __init insert_device(struct pnp_bios_node *node)
0300 {
0301     struct pnp_dev *dev;
0302     char id[8];
0303     int error;
0304
0305     /* check if the device is already added */
0306     list_for_each_entry(dev, &pnpbios_protocol.devices, protocol_list) {
0307         if (dev->number == node->handle)
0308             return -EEXIST;
0309     }
0310
0311     pnp_eisa_id_to_string(node->eisa_id & PNP_EISA_ID_MASK, id);
0312     dev = pnp_alloc_dev(&pnpbios_protocol, node->handle, id);
0313     if (!dev)
0314         return -ENOMEM;
0315
0316     pnpbios_parse_data_stream(dev, node);
0317     dev->active = pnp_is_active(dev);
0318     dev->flags = node->flags;
0319     if (!(dev->flags & PNPBIOS_NO_CONFIG))
0320         dev->capabilities |= PNP_CONFIGURABLE;
0321     if (!(dev->flags & PNPBIOS_NO_DISABLE) && pnpbios_is_dynamic(dev))
0322         dev->capabilities |= PNP_DISABLE;
0323     dev->capabilities |= PNP_READ;
0324     if (pnpbios_is_dynamic(dev))
0325         dev->capabilities |= PNP_WRITE;
0326     if (dev->flags & PNPBIOS_REMOVABLE)
0327         dev->capabilities |= PNP_REMOVABLE;
0328
0329     /* clear out the damaged flags */
0330     if (!dev->active)
0331         pnp_init_resources(dev);
0332
0333     error = pnp_add_device(dev);
0334     if (error) {
0335         put_device(&dev->dev);
0336         return error;
0337     }
0338
0339     pnpbios_interface_attach_device(node);
0340
0341     return 0;
0342 }
0343
0344 static void __init build_devlist(void)
0345 {
0346     u8 nodenum;
0347     unsigned int nodes_got = 0;
0348     unsigned int devs = 0;
0349     struct pnp_bios_node *node;
0350
0351     node = kzalloc(node_info.max_node_size, GFP_KERNEL);
0352     if (!node)
0353         return;
0354
0355     for (nodenum = 0; nodenum < 0xff;) {
0356         u8 thisnodenum = nodenum;
0357         /* eventually we will want to use PNPMODE_STATIC here but for now
0358          * dynamic will help us catch buggy bioses to add to the blacklist.
0359          */
0360         if (!pnpbios_dont_use_current_config) {
0361             if (pnp_bios_get_dev_node
0362                 (&nodenum, (char)PNPMODE_DYNAMIC, node))
0363                 break;
0364         } else {
0365             if (pnp_bios_get_dev_node
0366                 (&nodenum, (char)PNPMODE_STATIC, node))
0367                 break;
0368         }
0369         nodes_got++;
0370         if (insert_device(node) == 0)
0371             devs++;
0372         if (nodenum <= thisnodenum) {
0373             printk(KERN_ERR
0374                    "PnPBIOS: build_devlist: Node number 0x%x is out of sequence following node 0x%x. Aborting.\n",
0375                    (unsigned int)nodenum,
0376                    (unsigned int)thisnodenum);
0377             break;
0378         }
0379     }
0380     kfree(node);
0381
0382     printk(KERN_INFO
0383            "PnPBIOS: %i node%s reported by PnP BIOS; %i recorded by driver\n",
0384            nodes_got, nodes_got != 1 ? "s" : "", devs);
0385 }
0386
0387 /*
0388  *
0389  * INIT AND EXIT
0390  *
0391  */
0392
0393 static int pnpbios_disabled;
0394 int pnpbios_dont_use_current_config;
0395
0396 static int __init pnpbios_setup(char *str)
0397 {
0398     int invert;
0399
0400     while ((str != NULL) && (*str != '\0')) {
0401         if (strncmp(str, "off", 3) == 0)
0402             pnpbios_disabled = 1;
0403         if (strncmp(str, "on", 2) == 0)
0404             pnpbios_disabled = 0;
0405         invert = (strncmp(str, "no-", 3) == 0);
0406         if (invert)
0407             str += 3;
0408         if (strncmp(str, "curr", 4) == 0)
0409             pnpbios_dont_use_current_config = invert;
0410         str = strchr(str, ',');
0411         if (str != NULL)
0412             str += strspn(str, ", \t");
0413     }
0414
0415     return 1;
0416 }
0417
0418 __setup("pnpbios=", pnpbios_setup);
0419
0420 /* PnP BIOS signature: "$PnP" */
0421 #define PNP_SIGNATURE   (('$' << 0) + ('P' << 8) + ('n' << 16) + ('P' << 24))
0422
0423 static int __init pnpbios_probe_system(void)
0424 {
0425     union pnp_bios_install_struct *check;
0426     u8 sum;
0427     int length, i;
0428
0429     printk(KERN_INFO "PnPBIOS: Scanning system for PnP BIOS support...\n");
0430
0431     /*
0432      * Search the defined area (0xf0000-0xffff0) for a valid PnP BIOS
0433      * structure and, if one is found, sets up the selectors and
0434      * entry points
0435      */
0436     for (check = (union pnp_bios_install_struct *)__va(0xf0000);
0437          check < (union pnp_bios_install_struct *)__va(0xffff0);
0438          check = (void *)check + 16) {
0439         if (check->fields.signature != PNP_SIGNATURE)
0440             continue;
0441         printk(KERN_INFO
0442                "PnPBIOS: Found PnP BIOS installation structure at 0x%p\n",
0443                check);
0444         length = check->fields.length;
0445         if (!length) {
0446             printk(KERN_ERR
0447                    "PnPBIOS: installation structure is invalid, skipping\n");
0448             continue;
0449         }
0450         for (sum = 0, i = 0; i < length; i++)
0451             sum += check->chars[i];
0452         if (sum) {
0453             printk(KERN_ERR
0454                    "PnPBIOS: installation structure is corrupted, skipping\n");
0455             continue;
0456         }
0457         if (check->fields.version < 0x10) {
0458             printk(KERN_WARNING
0459                    "PnPBIOS: PnP BIOS version %d.%d is not supported\n",
0460                    check->fields.version >> 4,
0461                    check->fields.version & 15);
0462             continue;
0463         }
0464         printk(KERN_INFO
0465                "PnPBIOS: PnP BIOS version %d.%d, entry 0x%x:0x%x, dseg 0x%x\n",
0466                check->fields.version >> 4, check->fields.version & 15,
0467                check->fields.pm16cseg, check->fields.pm16offset,
0468                check->fields.pm16dseg);
0469         pnp_bios_install = check;
0470         return 1;
0471     }
0472
0473     printk(KERN_INFO "PnPBIOS: PnP BIOS support was not detected.\n");
0474     return 0;
0475 }
0476
0477 static int __init exploding_pnp_bios(const struct dmi_system_id *d)
0478 {
0479     printk(KERN_WARNING "%s detected. Disabling PnPBIOS\n", d->ident);
0480     return 0;
0481 }
0482
0483 static const struct dmi_system_id pnpbios_dmi_table[] __initconst = {
0484     {           /* PnPBIOS GPF on boot */
0485      .callback = exploding_pnp_bios,
0486      .ident = "Higraded P14H",
0487      .matches = {
0488              DMI_MATCH(DMI_BIOS_VENDOR, "American Megatrends Inc."),
0489              DMI_MATCH(DMI_BIOS_VERSION, "07.00T"),
0490              DMI_MATCH(DMI_SYS_VENDOR, "Higraded"),
0491              DMI_MATCH(DMI_PRODUCT_NAME, "P14H"),
0492              },
0493      },
0494     {           /* PnPBIOS GPF on boot */
0495      .callback = exploding_pnp_bios,
0496      .ident = "ASUS P4P800",
0497      .matches = {
0498              DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer Inc."),
0499              DMI_MATCH(DMI_BOARD_NAME, "P4P800"),
0500              },
0501      },
0502     {}
0503 };
0504
0505 static int __init pnpbios_init(void)
0506 {
0507     int ret;
0508
0509     if (pnpbios_disabled || dmi_check_system(pnpbios_dmi_table) ||
0510         arch_pnpbios_disabled()) {
0511         printk(KERN_INFO "PnPBIOS: Disabled\n");
0512         return -ENODEV;
0513     }
0514
0515 #ifdef CONFIG_PNPACPI
0516     if (!acpi_disabled && !pnpacpi_disabled) {
0517         pnpbios_disabled = 1;
0518         printk(KERN_INFO "PnPBIOS: Disabled by ACPI PNP\n");
0519         return -ENODEV;
0520     }
0521 #endif              /* CONFIG_ACPI */
0522
0523     /* scan the system for pnpbios support */
0524     if (!pnpbios_probe_system())
0525         return -ENODEV;
0526
0527     /* make preparations for bios calls */
0528     pnpbios_calls_init(pnp_bios_install);
0529
0530     /* read the node info */
0531     ret = pnp_bios_dev_node_info(&node_info);
0532     if (ret) {
0533         printk(KERN_ERR
0534                "PnPBIOS: Unable to get node info.  Aborting.\n");
0535         return ret;
0536     }
0537
0538     /* register with the pnp layer */
0539     ret = pnp_register_protocol(&pnpbios_protocol);
0540     if (ret) {
0541         printk(KERN_ERR
0542                "PnPBIOS: Unable to register driver.  Aborting.\n");
0543         return ret;
0544     }
0545
0546     /* start the proc interface */
0547     ret = pnpbios_proc_init();
0548     if (ret)
0549         printk(KERN_ERR "PnPBIOS: Failed to create proc interface.\n");
0550
0551     /* scan for pnpbios devices */
0552     build_devlist();
0553
0554     pnp_platform_devices = 1;
0555     return 0;
0556 }
0557
0558 fs_initcall(pnpbios_init);
0559
0560 static int __init pnpbios_thread_init(void)
0561 {
0562     struct task_struct *task;
0563
0564     if (pnpbios_disabled)
0565         return 0;
0566
0567     init_completion(&unload_sem);
0568     task = kthread_run(pnp_dock_thread, NULL, "kpnpbiosd");
0569     return PTR_ERR_OR_ZERO(task);
0570 }
0571
0572 /* Start the kernel thread later: */
0573 device_initcall(pnpbios_thread_init);
0574
0575 EXPORT_SYMBOL(pnpbios_protocol);