/*
 *  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);
}

static 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;
}