// SPDX-License-Identifier: GPL-2.0-or-later
/*
* pnpbios -- PnP BIOS driver
*
* This driver provides access to Plug-'n'-Play services provided by
* the PnP BIOS firmware, described in the following documents:
* Plug and Play BIOS Specification, Version 1.0A, 5 May 1994
* Plug and Play BIOS Clarification Paper, 6 October 1994
* Compaq Computer Corporation, Phoenix Technologies Ltd., Intel Corp.
*
* Originally (C) 1998 Christian Schmidt <schmidt@digadd.de>
* Modifications (C) 1998 Tom Lees <tom@lpsg.demon.co.uk>
* Minor reorganizations by David Hinds <dahinds@users.sourceforge.net>
* Further modifications (C) 2001, 2002 by:
* Alan Cox <alan@redhat.com>
* Thomas Hood
* Brian Gerst <bgerst@didntduck.org>
*
* Ported to the PnP Layer and several additional improvements (C) 2002
* by Adam Belay <ambx1@neo.rr.com>
*/
/* Change Log
*
* Adam Belay - <ambx1@neo.rr.com> - March 16, 2003
* rev 1.01 Only call pnp_bios_dev_node_info once
* Added pnpbios_print_status
* Added several new error messages and info messages
* Added pnpbios_interface_attach_device
* integrated core and proc init system
* Introduced PNPMODE flags
* Removed some useless includes
*/
#include <linux/types.h>
#include <linux/init.h>
#include <linux/linkage.h>
#include <linux/kernel.h>
#include <linux/device.h>
#include <linux/pnp.h>
#include <linux/mm.h>
#include <linux/smp.h>
#include <linux/slab.h>
#include <linux/completion.h>
#include <linux/spinlock.h>
#include <linux/dmi.h>
#include <linux/delay.h>
#include <linux/acpi.h>
#include <linux/freezer.h>
#include <linux/kmod.h>
#include <linux/kthread.h>
#include <asm/page.h>
#include <asm/desc.h>
#include <asm/byteorder.h>
#include "../base.h"
#include "pnpbios.h"
/*
*
* PnP BIOS INTERFACE
*
*/
static union pnp_bios_install_struct *pnp_bios_install = NULL;
int pnp_bios_present(void)
{
return (pnp_bios_install != NULL);
}
struct pnp_dev_node_info node_info;
/*
*
* DOCKING FUNCTIONS
*
*/
static struct completion unload_sem;
/*
* (Much of this belongs in a shared routine somewhere)
*/
static int pnp_dock_event(int dock, struct pnp_docking_station_info *info)
{
static char const sbin_pnpbios[] = "/sbin/pnpbios";
char *argv[3], **envp, *buf, *scratch;
int i = 0, value;
if (!(envp = kcalloc(20, sizeof(char *), GFP_KERNEL)))
return -ENOMEM;
if (!(buf = kzalloc(256, GFP_KERNEL))) {
kfree(envp);
return -ENOMEM;
}
/* FIXME: if there are actual users of this, it should be
* integrated into the driver core and use the usual infrastructure
* like sysfs and uevents
*/
argv[0] = (char *)sbin_pnpbios;
argv[1] = "dock";
argv[2] = NULL;
/* minimal command environment */
envp[i++] = "HOME=/";
envp[i++] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin";
#ifdef DEBUG
/* hint that policy agent should enter no-stdout debug mode */
envp[i++] = "DEBUG=kernel";
#endif
/* extensible set of named bus-specific parameters,
* supporting multiple driver selection algorithms.
*/
scratch = buf;
/* action: add, remove */
envp[i++] = scratch;
scratch += sprintf(scratch, "ACTION=%s", dock ? "add" : "remove") + 1;
/* Report the ident for the dock */
envp[i++] = scratch;
scratch += sprintf(scratch, "DOCK=%x/%x/%x",
info->location_id, info->serial, info->capabilities);
envp[i] = NULL;
value = call_usermodehelper(sbin_pnpbios, argv, envp, UMH_WAIT_EXEC);
kfree(buf);
kfree(envp);
return 0;
}
/*
* Poll the PnP docking at regular intervals
*/
static int pnp_dock_thread(void *unused)
{
static struct pnp_docking_station_info now;
int docked = -1, d = 0;
set_freezable();
while (1) {
int status;
/*
* Poll every 2 seconds
*/
msleep_interruptible(2000);
if (try_to_freeze())
continue;
status = pnp_bios_dock_station_info(&now);
switch (status) {
/*
* No dock to manage
*/
case PNP_FUNCTION_NOT_SUPPORTED:
kthread_complete_and_exit(&unload_sem, 0);
case PNP_SYSTEM_NOT_DOCKED:
d = 0;
break;
case PNP_SUCCESS:
d = 1;
break;
default:
pnpbios_print_status("pnp_dock_thread", status);
printk(KERN_WARNING "PnPBIOS: disabling dock monitoring.\n");
kthread_complete_and_exit(&unload_sem, 0);
}
if (d != docked) {
if (pnp_dock_event(d, &now) == 0) {
docked = d;
#if 0
printk(KERN_INFO
"PnPBIOS: Docking station %stached\n",
docked ? "at" : "de");
#endif
}
}
}
kthread_complete_and_exit(&unload_sem, 0);
}
static int pnpbios_get_resources(struct pnp_dev *dev)
{
u8 nodenum = dev->number;
struct pnp_bios_node *node;
if (!pnpbios_is_dynamic(dev))
return -EPERM;
pnp_dbg(&dev->dev, "get resources\n");
node = kzalloc(node_info.max_node_size, GFP_KERNEL);
if (!node)
return -1;
if (pnp_bios_get_dev_node(&nodenum, (char)PNPMODE_DYNAMIC, node)) {
kfree(node);
return -ENODEV;
}
pnpbios_read_resources_from_node(dev, node);
dev->active = pnp_is_active(dev);
kfree(node);
return 0;
}
static int pnpbios_set_resources(struct pnp_dev *dev)
{
u8 nodenum = dev->number;
struct pnp_bios_node *node;
int ret;
if (!pnpbios_is_dynamic(dev))
return -EPERM;
pnp_dbg(&dev->dev, "set resources\n");
node = kzalloc(node_info.max_node_size, GFP_KERNEL);
if (!node)
return -1;
if (pnp_bios_get_dev_node(&nodenum, (char)PNPMODE_DYNAMIC, node)) {
kfree(node);
return -ENODEV;
}
if (pnpbios_write_resources_to_node(dev, node) < 0) {
kfree(node);
return -1;
}
ret = pnp_bios_set_dev_node(node->handle, (char)PNPMODE_DYNAMIC, node);
kfree(node);
if (ret > 0)
ret = -1;
return ret;
}
static void pnpbios_zero_data_stream(struct pnp_bios_node *node)
{
unsigned char *p = (char *)node->data;
unsigned char *end = (char *)(node->data + node->size);
unsigned int len;
int i;
while ((char *)p < (char *)end) {
if (p[0] & 0x80) { /* large tag */
len = (p[2] << 8) | p[1];
p += 3;
} else {
if (((p[0] >> 3) & 0x0f) == 0x0f)
return;
len = p[0] & 0x07;
p += 1;
}
for (i = 0; i < len; i++)
p[i] = 0;
p += len;
}
printk(KERN_ERR
"PnPBIOS: Resource structure did not contain an end tag.\n");
}
static int pnpbios_disable_resources(struct pnp_dev *dev)
{
struct pnp_bios_node *node;
u8 nodenum = dev->number;
int ret;
if (dev->flags & PNPBIOS_NO_DISABLE || !pnpbios_is_dynamic(dev))
return -EPERM;
node = kzalloc(node_info.max_node_size, GFP_KERNEL);
if (!node)
return -ENOMEM;
if (pnp_bios_get_dev_node(&nodenum, (char)PNPMODE_DYNAMIC, node)) {
kfree(node);
return -ENODEV;
}
pnpbios_zero_data_stream(node);
ret = pnp_bios_set_dev_node(dev->number, (char)PNPMODE_DYNAMIC, node);
kfree(node);
if (ret > 0)
ret = -1;
return ret;
}
/* PnP Layer support */
struct pnp_protocol pnpbios_protocol = {
.name = "Plug and Play BIOS",
.get = pnpbios_get_resources,
.set = pnpbios_set_resources,
.disable = pnpbios_disable_resources,
};
static int __init insert_device(struct pnp_bios_node *node)
{
struct pnp_dev *dev;
char id[8];
int error;
/* check if the device is already added */
list_for_each_entry(dev, &pnpbios_protocol.devices, protocol_list) {
if (dev->number == node->handle)
return -EEXIST;
}
pnp_eisa_id_to_string(node->eisa_id & PNP_EISA_ID_MASK, id);
dev = pnp_alloc_dev(&pnpbios_protocol, node->handle, id);
if (!dev)
return -ENOMEM;
pnpbios_parse_data_stream(dev, node);
dev->active = pnp_is_active(dev);
dev->flags = node->flags;
if (!(dev->flags & PNPBIOS_NO_CONFIG))
dev->capabilities |= PNP_CONFIGURABLE;
if (!(dev->flags & PNPBIOS_NO_DISABLE) && pnpbios_is_dynamic(dev))
dev->capabilities |= PNP_DISABLE;
dev->capabilities |= PNP_READ;
if (pnpbios_is_dynamic(dev))
dev->capabilities |= PNP_WRITE;
if (dev->flags & PNPBIOS_REMOVABLE)
dev->capabilities |= PNP_REMOVABLE;
/* clear out the damaged flags */
if (!dev->active)
pnp_init_resources(dev);
error = pnp_add_device(dev);
if (error) {
put_device(&dev->dev);
return error;
}
pnpbios_interface_attach_device(node);
return 0;
}
static void __init build_devlist(void)
{
u8 nodenum;
unsigned int nodes_got = 0;
unsigned int devs = 0;
struct pnp_bios_node *node;
node = kzalloc(node_info.max_node_size, GFP_KERNEL);
if (!node)
return;
for (nodenum = 0; nodenum < 0xff;) {
u8 thisnodenum = nodenum;
/* eventually we will want to use PNPMODE_STATIC here but for now
* dynamic will help us catch buggy bioses to add to the blacklist.
*/
if (!pnpbios_dont_use_current_config) {
if (pnp_bios_get_dev_node
(&nodenum, (char)PNPMODE_DYNAMIC, node))
break;
} else {
if (pnp_bios_get_dev_node
(&nodenum, (char)PNPMODE_STATIC, node))
break;
}
nodes_got++;
if (insert_device(node) == 0)
devs++;
if (nodenum <= thisnodenum) {
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);
break;
}
}
kfree(node);
printk(KERN_INFO
"PnPBIOS: %i node%s reported by PnP BIOS; %i recorded by driver\n",
nodes_got, nodes_got != 1 ? "s" : "", devs);
}
/*
*
* INIT AND EXIT
*
*/
static int pnpbios_disabled;
int pnpbios_dont_use_current_config;
static int __init pnpbios_setup(char *str)
{
int invert;
while ((str != NULL) && (*str != '\0')) {
if (strncmp(str, "off", 3) == 0)
pnpbios_disabled = 1;
if (strncmp(str, "on", 2) == 0)
pnpbios_disabled = 0;
invert = (strncmp(str, "no-", 3) == 0);
if (invert)
str += 3;
if (strncmp(str, "curr", 4) == 0)
pnpbios_dont_use_current_config = invert;
str = strchr(str, ',');
if (str != NULL)
str += strspn(str, ", \t");
}
return 1;
}
__setup("pnpbios=", pnpbios_setup);
/* PnP BIOS signature: "$PnP" */
#define PNP_SIGNATURE (('$' << 0) + ('P' << 8) + ('n' << 16) + ('P' << 24))
static int __init pnpbios_probe_system(void)
{
union pnp_bios_install_struct *check;
u8 sum;
int length, i;
printk(KERN_INFO "PnPBIOS: Scanning system for PnP BIOS support...\n");
/*
* Search the defined area (0xf0000-0xffff0) for a valid PnP BIOS
* structure and, if one is found, sets up the selectors and
* entry points
*/
for (check = (union pnp_bios_install_struct *)__va(0xf0000);
check < (union pnp_bios_install_struct *)__va(0xffff0);
check = (void *)check + 16) {
if (check->fields.signature != PNP_SIGNATURE)
continue;
printk(KERN_INFO
"PnPBIOS: Found PnP BIOS installation structure at 0x%p\n",
check);
length = check->fields.length;
if (!length) {
printk(KERN_ERR
"PnPBIOS: installation structure is invalid, skipping\n");
continue;
}
for (sum = 0, i = 0; i < length; i++)
sum += check->chars[i];
if (sum) {
printk(KERN_ERR
"PnPBIOS: installation structure is corrupted, skipping\n");
continue;
}
if (check->fields.version < 0x10) {
printk(KERN_WARNING
"PnPBIOS: PnP BIOS version %d.%d is not supported\n",
check->fields.version >> 4,
check->fields.version & 15);
continue;
}
printk(KERN_INFO
"PnPBIOS: PnP BIOS version %d.%d, entry 0x%x:0x%x, dseg 0x%x\n",
check->fields.version >> 4, check->fields.version & 15,
check->fields.pm16cseg, check->fields.pm16offset,
check->fields.pm16dseg);
pnp_bios_install = check;
return 1;
}
printk(KERN_INFO "PnPBIOS: PnP BIOS support was not detected.\n");
return 0;
}
static int __init exploding_pnp_bios(const struct dmi_system_id *d)
{
printk(KERN_WARNING "%s detected. Disabling PnPBIOS\n", d->ident);
return 0;
}
static const struct dmi_system_id pnpbios_dmi_table[] __initconst = {
{ /* PnPBIOS GPF on boot */
.callback = exploding_pnp_bios,
.ident = "Higraded P14H",
.matches = {
DMI_MATCH(DMI_BIOS_VENDOR, "American Megatrends Inc."),
DMI_MATCH(DMI_BIOS_VERSION, "07.00T"),
DMI_MATCH(DMI_SYS_VENDOR, "Higraded"),
DMI_MATCH(DMI_PRODUCT_NAME, "P14H"),
},
},
{ /* PnPBIOS GPF on boot */
.callback = exploding_pnp_bios,
.ident = "ASUS P4P800",
.matches = {
DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer Inc."),
DMI_MATCH(DMI_BOARD_NAME, "P4P800"),
},
},
{}
};
static int __init pnpbios_init(void)
{
int ret;
if (pnpbios_disabled || dmi_check_system(pnpbios_dmi_table) ||
arch_pnpbios_disabled()) {
printk(KERN_INFO "PnPBIOS: Disabled\n");
return -ENODEV;
}
#ifdef CONFIG_PNPACPI
if (!acpi_disabled && !pnpacpi_disabled) {
pnpbios_disabled = 1;
printk(KERN_INFO "PnPBIOS: Disabled by ACPI PNP\n");
return -ENODEV;
}
#endif /* CONFIG_ACPI */
/* scan the system for pnpbios support */
if (!pnpbios_probe_system())
return -ENODEV;
/* make preparations for bios calls */
pnpbios_calls_init(pnp_bios_install);
/* read the node info */
ret = pnp_bios_dev_node_info(&node_info);
if (ret) {
printk(KERN_ERR
"PnPBIOS: Unable to get node info. Aborting.\n");
return ret;
}
/* register with the pnp layer */
ret = pnp_register_protocol(&pnpbios_protocol);
if (ret) {
printk(KERN_ERR
"PnPBIOS: Unable to register driver. Aborting.\n");
return ret;
}
/* start the proc interface */
ret = pnpbios_proc_init();
if (ret)
printk(KERN_ERR "PnPBIOS: Failed to create proc interface.\n");
/* scan for pnpbios devices */
build_devlist();
pnp_platform_devices = 1;
return 0;
}
fs_initcall(pnpbios_init);
static int __init pnpbios_thread_init(void)
{
struct task_struct *task;
if (pnpbios_disabled)
return 0;
init_completion(&unload_sem);
task = kthread_run(pnp_dock_thread, NULL, "kpnpbiosd");
return PTR_ERR_OR_ZERO(task);
}
/* Start the kernel thread later: */
device_initcall(pnpbios_thread_init);
EXPORT_SYMBOL(pnpbios_protocol);