/*
 *  osi.c - _OSI implementation
 *
 *  Copyright (C) 2016 Intel Corporation
 *    Author: Lv Zheng <lv.zheng@intel.com>
 *
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 *
 *  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 of the License, 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.
 *
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 */

/* Uncomment next line to get verbose printout */
/* #define DEBUG */
#define pr_fmt(fmt) "ACPI: " fmt

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/acpi.h>
#include <linux/dmi.h>

#include "internal.h"


#define OSI_STRING_LENGTH_MAX   64
#define OSI_STRING_ENTRIES_MAX  16

struct acpi_osi_entry {
        char string[OSI_STRING_LENGTH_MAX];
        bool enable;
};

static struct acpi_osi_config {
        u8              default_disabling;
        unsigned int    linux_enable:1;
        unsigned int    linux_dmi:1;
        unsigned int    linux_cmdline:1;
        unsigned int    darwin_enable:1;
        unsigned int    darwin_dmi:1;
        unsigned int    darwin_cmdline:1;
} osi_config;

static struct acpi_osi_config osi_config;
static struct acpi_osi_entry
osi_setup_entries[OSI_STRING_ENTRIES_MAX] __initdata = {
        {"Module Device", true},
        {"Processor Device", true},
        {"3.0 _SCP Extensions", true},
        {"Processor Aggregator Device", true},
};

static u32 acpi_osi_handler(acpi_string interface, u32 supported)
{
        if (!strcmp("Linux", interface)) {
                pr_notice_once(FW_BUG
                        "BIOS _OSI(Linux) query %s%s\n",
                        osi_config.linux_enable ? "honored" : "ignored",
                        osi_config.linux_cmdline ? " via cmdline" :
                        osi_config.linux_dmi ? " via DMI" : "");
        }
        if (!strcmp("Darwin", interface)) {
                pr_notice_once(
                        "BIOS _OSI(Darwin) query %s%s\n",
                        osi_config.darwin_enable ? "honored" : "ignored",
                        osi_config.darwin_cmdline ? " via cmdline" :
                        osi_config.darwin_dmi ? " via DMI" : "");
        }

        return supported;
}

void __init acpi_osi_setup(char *str)
{
        struct acpi_osi_entry *osi;
        bool enable = true;
        int i;

        if (!acpi_gbl_create_osi_method)
                return;

        if (str == NULL || *str == '\0') {
                pr_info("_OSI method disabled\n");
                acpi_gbl_create_osi_method = FALSE;
                return;
        }

        if (*str == '!') {
                str++;
                if (*str == '\0') {
                        /* Do not override acpi_osi=!* */
                        if (!osi_config.default_disabling)
                                osi_config.default_disabling =
                                        ACPI_DISABLE_ALL_VENDOR_STRINGS;
                        return;
                } else if (*str == '*') {
                        osi_config.default_disabling = ACPI_DISABLE_ALL_STRINGS;
                        for (i = 0; i < OSI_STRING_ENTRIES_MAX; i++) {
                                osi = &osi_setup_entries[i];
                                osi->enable = false;
                        }
                        return;
                } else if (*str == '!') {
                        osi_config.default_disabling = 0;
                        return;
                }
                enable = false;
        }

        for (i = 0; i < OSI_STRING_ENTRIES_MAX; i++) {
                osi = &osi_setup_entries[i];
                if (!strcmp(osi->string, str)) {
                        osi->enable = enable;
                        break;
                } else if (osi->string[0] == '\0') {
                        osi->enable = enable;
                        strncpy(osi->string, str, OSI_STRING_LENGTH_MAX);
                        break;
                }
        }
}

static void __init __acpi_osi_setup_darwin(bool enable)
{
        osi_config.darwin_enable = !!enable;
        if (enable) {
                acpi_osi_setup("!");
                acpi_osi_setup("Darwin");
        } else {
                acpi_osi_setup("!!");
                acpi_osi_setup("!Darwin");
        }
}

static void __init acpi_osi_setup_darwin(bool enable)
{
        /* Override acpi_osi_dmi_blacklisted() */
        osi_config.darwin_dmi = 0;
        osi_config.darwin_cmdline = 1;
        __acpi_osi_setup_darwin(enable);
}

/*
 * The story of _OSI(Linux)
 *
 * From pre-history through Linux-2.6.22, Linux responded TRUE upon a BIOS
 * OSI(Linux) query.
 *
 * Unfortunately, reference BIOS writers got wind of this and put
 * OSI(Linux) in their example code, quickly exposing this string as
 * ill-conceived and opening the door to an un-bounded number of BIOS
 * incompatibilities.
 *
 * For example, OSI(Linux) was used on resume to re-POST a video card on
 * one system, because Linux at that time could not do a speedy restore in
 * its native driver. But then upon gaining quick native restore
 * capability, Linux has no way to tell the BIOS to skip the time-consuming
 * POST -- putting Linux at a permanent performance disadvantage. On
 * another system, the BIOS writer used OSI(Linux) to infer native OS
 * support for IPMI!  On other systems, OSI(Linux) simply got in the way of
 * Linux claiming to be compatible with other operating systems, exposing
 * BIOS issues such as skipped device initialization.
 *
 * So "Linux" turned out to be a really poor chose of OSI string, and from
 * Linux-2.6.23 onward we respond FALSE.
 *
 * BIOS writers should NOT query _OSI(Linux) on future systems. Linux will
 * complain on the console when it sees it, and return FALSE. To get Linux
 * to return TRUE for your system  will require a kernel source update to
 * add a DMI entry, or boot with "acpi_osi=Linux"
 */
static void __init __acpi_osi_setup_linux(bool enable)
{
        osi_config.linux_enable = !!enable;
        if (enable)
                acpi_osi_setup("Linux");
        else
                acpi_osi_setup("!Linux");
}

static void __init acpi_osi_setup_linux(bool enable)
{
        /* Override acpi_osi_dmi_blacklisted() */
        osi_config.linux_dmi = 0;
        osi_config.linux_cmdline = 1;
        __acpi_osi_setup_linux(enable);
}

/*
 * Modify the list of "OS Interfaces" reported to BIOS via _OSI
 *
 * empty string disables _OSI
 * string starting with '!' disables that string
 * otherwise string is added to list, augmenting built-in strings
 */
static void __init acpi_osi_setup_late(void)
{
        struct acpi_osi_entry *osi;
        char *str;
        int i;
        acpi_status status;

        if (osi_config.default_disabling) {
                status = acpi_update_interfaces(osi_config.default_disabling);
                if (ACPI_SUCCESS(status))
                        pr_info("Disabled all _OSI OS vendors%s\n",
                                osi_config.default_disabling ==
                                ACPI_DISABLE_ALL_STRINGS ?
                                " and feature groups" : "");
        }

        for (i = 0; i < OSI_STRING_ENTRIES_MAX; i++) {
                osi = &osi_setup_entries[i];
                str = osi->string;
                if (*str == '\0')
                        break;
                if (osi->enable) {
                        status = acpi_install_interface(str);
                        if (ACPI_SUCCESS(status))
                                pr_info("Added _OSI(%s)\n", str);
                } else {
                        status = acpi_remove_interface(str);
                        if (ACPI_SUCCESS(status))
                                pr_info("Deleted _OSI(%s)\n", str);
                }
        }
}

static int __init osi_setup(char *str)
{
        if (str && !strcmp("Linux", str))
                acpi_osi_setup_linux(true);
        else if (str && !strcmp("!Linux", str))
                acpi_osi_setup_linux(false);
        else if (str && !strcmp("Darwin", str))
                acpi_osi_setup_darwin(true);
        else if (str && !strcmp("!Darwin", str))
                acpi_osi_setup_darwin(false);
        else
                acpi_osi_setup(str);

        return 1;
}
__setup("acpi_osi=", osi_setup);

bool acpi_osi_is_win8(void)
{
        return acpi_gbl_osi_data >= ACPI_OSI_WIN_8;
}
EXPORT_SYMBOL(acpi_osi_is_win8);

static void __init acpi_osi_dmi_darwin(bool enable,
                                       const struct dmi_system_id *d)
{
        pr_notice("DMI detected to setup _OSI(\"Darwin\"): %s\n", d->ident);
        osi_config.darwin_dmi = 1;
        __acpi_osi_setup_darwin(enable);
}

void __init acpi_osi_dmi_linux(bool enable, const struct dmi_system_id *d)
{
        pr_notice("DMI detected to setup _OSI(\"Linux\"): %s\n", d->ident);
        osi_config.linux_dmi = 1;
        __acpi_osi_setup_linux(enable);
}

static int __init dmi_enable_osi_darwin(const struct dmi_system_id *d)
{
        acpi_osi_dmi_darwin(true, d);

        return 0;
}

static int __init dmi_enable_osi_linux(const struct dmi_system_id *d)
{
        acpi_osi_dmi_linux(true, d);

        return 0;
}

static int __init dmi_disable_osi_vista(const struct dmi_system_id *d)
{
        pr_notice("DMI detected: %s\n", d->ident);
        acpi_osi_setup("!Windows 2006");
        acpi_osi_setup("!Windows 2006 SP1");
        acpi_osi_setup("!Windows 2006 SP2");

        return 0;
}

static int __init dmi_disable_osi_win7(const struct dmi_system_id *d)
{
        pr_notice("DMI detected: %s\n", d->ident);
        acpi_osi_setup("!Windows 2009");

        return 0;
}

static int __init dmi_disable_osi_win8(const struct dmi_system_id *d)
{
        pr_notice("DMI detected: %s\n", d->ident);
        acpi_osi_setup("!Windows 2012");

        return 0;
}

/*
 * Linux default _OSI response behavior is determined by this DMI table.
 *
 * Note that _OSI("Linux")/_OSI("Darwin") determined here can be overridden
 * by acpi_osi=!Linux/acpi_osi=!Darwin command line options.
 */
static struct dmi_system_id acpi_osi_dmi_table[] __initdata = {
        {
        .callback = dmi_disable_osi_vista,
        .ident = "Fujitsu Siemens",
        .matches = {
                     DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU SIEMENS"),
                     DMI_MATCH(DMI_PRODUCT_NAME, "ESPRIMO Mobile V5505"),
                },
        },
        {
        /*
         * There have a NVIF method in MSI GX723 DSDT need call by Nvidia
         * driver (e.g. nouveau) when user press brightness hotkey.
         * Currently, nouveau driver didn't do the job and it causes there
         * have a infinite while loop in DSDT when user press hotkey.
         * We add MSI GX723's dmi information to this table for workaround
         * this issue.
         * Will remove MSI GX723 from the table after nouveau grows support.
         */
        .callback = dmi_disable_osi_vista,
        .ident = "MSI GX723",
        .matches = {
                     DMI_MATCH(DMI_SYS_VENDOR, "Micro-Star International"),
                     DMI_MATCH(DMI_PRODUCT_NAME, "GX723"),
                },
        },
        {
        .callback = dmi_disable_osi_vista,
        .ident = "Sony VGN-NS10J_S",
        .matches = {
                     DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
                     DMI_MATCH(DMI_PRODUCT_NAME, "VGN-NS10J_S"),
                },
        },
        {
        .callback = dmi_disable_osi_vista,
        .ident = "Sony VGN-SR290J",
        .matches = {
                     DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
                     DMI_MATCH(DMI_PRODUCT_NAME, "VGN-SR290J"),
                },
        },
        {
        .callback = dmi_disable_osi_vista,
        .ident = "VGN-NS50B_L",
        .matches = {
                     DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
                     DMI_MATCH(DMI_PRODUCT_NAME, "VGN-NS50B_L"),
                },
        },
        {
        .callback = dmi_disable_osi_vista,
        .ident = "VGN-SR19XN",
        .matches = {
                     DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
                     DMI_MATCH(DMI_PRODUCT_NAME, "VGN-SR19XN"),
                },
        },
        {
        .callback = dmi_disable_osi_vista,
        .ident = "Toshiba Satellite L355",
        .matches = {
                     DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
                     DMI_MATCH(DMI_PRODUCT_VERSION, "Satellite L355"),
                },
        },
        {
        .callback = dmi_disable_osi_win7,
        .ident = "ASUS K50IJ",
        .matches = {
                     DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
                     DMI_MATCH(DMI_PRODUCT_NAME, "K50IJ"),
                },
        },
        {
        .callback = dmi_disable_osi_vista,
        .ident = "Toshiba P305D",
        .matches = {
                     DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
                     DMI_MATCH(DMI_PRODUCT_NAME, "Satellite P305D"),
                },
        },
        {
        .callback = dmi_disable_osi_vista,
        .ident = "Toshiba NB100",
        .matches = {
                     DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
                     DMI_MATCH(DMI_PRODUCT_NAME, "NB100"),
                },
        },

        /*
         * The wireless hotkey does not work on those machines when
         * returning true for _OSI("Windows 2012")
         */
        {
        .callback = dmi_disable_osi_win8,
        .ident = "Dell Inspiron 7737",
        .matches = {
                    DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
                    DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 7737"),
                },
        },
        {
        .callback = dmi_disable_osi_win8,
        .ident = "Dell Inspiron 7537",
        .matches = {
                    DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
                    DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 7537"),
                },
        },
        {
        .callback = dmi_disable_osi_win8,
        .ident = "Dell Inspiron 5437",
        .matches = {
                    DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
                    DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 5437"),
                },
        },
        {
        .callback = dmi_disable_osi_win8,
        .ident = "Dell Inspiron 3437",
        .matches = {
                    DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
                    DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 3437"),
                },
        },
        {
        .callback = dmi_disable_osi_win8,
        .ident = "Dell Vostro 3446",
        .matches = {
                    DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
                    DMI_MATCH(DMI_PRODUCT_NAME, "Vostro 3446"),
                },
        },
        {
        .callback = dmi_disable_osi_win8,
        .ident = "Dell Vostro 3546",
        .matches = {
                    DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
                    DMI_MATCH(DMI_PRODUCT_NAME, "Vostro 3546"),
                },
        },

        /*
         * BIOS invocation of _OSI(Linux) is almost always a BIOS bug.
         * Linux ignores it, except for the machines enumerated below.
         */

        /*
         * Without this this EEEpc exports a non working WMI interface, with
         * this it exports a working "good old" eeepc_laptop interface, fixing
         * both brightness control, and rfkill not working.
         */
        {
        .callback = dmi_enable_osi_linux,
        .ident = "Asus EEE PC 1015PX",
        .matches = {
                     DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer INC."),
                     DMI_MATCH(DMI_PRODUCT_NAME, "1015PX"),
                },
        },

        /*
         * Enable _OSI("Darwin") for all apple platforms.
         */
        {
        .callback = dmi_enable_osi_darwin,
        .ident = "Apple hardware",
        .matches = {
                     DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
                },
        },
        {
        .callback = dmi_enable_osi_darwin,
        .ident = "Apple hardware",
        .matches = {
                     DMI_MATCH(DMI_SYS_VENDOR, "Apple Computer, Inc."),
                },
        },
        {}
};

static __init void acpi_osi_dmi_blacklisted(void)
{
        dmi_check_system(acpi_osi_dmi_table);
}

int __init early_acpi_osi_init(void)
{
        acpi_osi_dmi_blacklisted();

        return 0;
}

int __init acpi_osi_init(void)
{
        acpi_install_interface_handler(acpi_osi_handler);
        acpi_osi_setup_late();

        return 0;
}