core.c

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/*
 * 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 <[email protected]>
 * Modifications (C) 1998 Tom Lees <[email protected]>
 * Minor reorganizations by David Hinds <[email protected]>
 * Further modifications (C) 2001, 2002 by:
 *   Alan Cox <[email protected]>
 *   Thomas Hood
 *   Brian Gerst <[email protected]>
 *
 * Ported to the PnP Layer and several additional improvements (C) 2002
 * by Adam Belay <[email protected]>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation; either version 2, or (at your option) any
 * later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

/* Change Log
 *
 * Adam Belay - <[email protected]> - 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/module.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/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
 *
 */

#ifdef CONFIG_HOTPLUG

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)
{
    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] = "/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(argv [0], 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:
            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);
            continue;
        }
        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
            }
        }
    }
    complete_and_exit(&unload_sem, 0);
}

#endif              /* CONFIG_HOTPLUG */

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 list_head *pos;
    struct pnp_dev *dev;
    char id[8];

    /* check if the device is already added */
    list_for_each(pos, &pnpbios_protocol.devices) {
        dev = list_entry(pos, struct pnp_dev, protocol_list);
        if (dev->number == node->handle)
            return -1;
    }

    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 -1;

    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);

    pnp_add_device(dev);
    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 struct dmi_system_id pnpbios_dmi_table[] __initdata = {
    {           /* 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 defined(CONFIG_PPC)
    if (check_legacy_ioport(PNPBIOS_BASE))
        return -ENODEV;
#endif
    if (pnpbios_disabled || dmi_check_system(pnpbios_dmi_table) ||
        paravirt_enabled()) {
        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)
{
#if defined(CONFIG_PPC)
    if (check_legacy_ioport(PNPBIOS_BASE))
        return 0;
#endif
    if (pnpbios_disabled)
        return 0;
#ifdef CONFIG_HOTPLUG
    {
        struct task_struct *task;
        init_completion(&unload_sem);
        task = kthread_run(pnp_dock_thread, NULL, "kpnpbiosd");
        if (IS_ERR(task))
            return PTR_ERR(task);
    }
#endif
    return 0;
}

/* Start the kernel thread later: */
module_init(pnpbios_thread_init);

EXPORT_SYMBOL(pnpbios_protocol);