Merge tag 'mmc-v4.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/ulfh/mmc

[mirror_ubuntu-artful-kernel.git] / drivers / acpi / bus.c

/*
 *  acpi_bus.c - ACPI Bus Driver ($Revision: 80 $)
 *
 *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@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.
 *
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/ioport.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/sched.h>
#include <linux/pm.h>
#include <linux/device.h>
#include <linux/proc_fs.h>
#include <linux/acpi.h>
#include <linux/slab.h>
#include <linux/regulator/machine.h>
#include <linux/workqueue.h>
#include <linux/reboot.h>
#include <linux/delay.h>
#ifdef CONFIG_X86
#include <asm/mpspec.h>
#endif
#include <linux/acpi_iort.h>
#include <linux/pci.h>
#include <acpi/apei.h>
#include <linux/dmi.h>
#include <linux/suspend.h>

#include "internal.h"

#define _COMPONENT              ACPI_BUS_COMPONENT
ACPI_MODULE_NAME("bus");

struct acpi_device *acpi_root;
struct proc_dir_entry *acpi_root_dir;
EXPORT_SYMBOL(acpi_root_dir);

#ifdef CONFIG_X86
#ifdef CONFIG_ACPI_CUSTOM_DSDT
static inline int set_copy_dsdt(const struct dmi_system_id *id)
{
        return 0;
}
#else
static int set_copy_dsdt(const struct dmi_system_id *id)
{
        printk(KERN_NOTICE "%s detected - "
                "force copy of DSDT to local memory\n", id->ident);
        acpi_gbl_copy_dsdt_locally = 1;
        return 0;
}
#endif

static struct dmi_system_id dsdt_dmi_table[] __initdata = {
        /*
         * Invoke DSDT corruption work-around on all Toshiba Satellite.
         * https://bugzilla.kernel.org/show_bug.cgi?id=14679
         */
        {
         .callback = set_copy_dsdt,
         .ident = "TOSHIBA Satellite",
         .matches = {
                DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
                DMI_MATCH(DMI_PRODUCT_NAME, "Satellite"),
                },
        },
        {}
};
#else
static struct dmi_system_id dsdt_dmi_table[] __initdata = {
        {}
};
#endif

/* --------------------------------------------------------------------------
                                Device Management
   -------------------------------------------------------------------------- */

acpi_status acpi_bus_get_status_handle(acpi_handle handle,
                                       unsigned long long *sta)
{
        acpi_status status;

        status = acpi_evaluate_integer(handle, "_STA", NULL, sta);
        if (ACPI_SUCCESS(status))
                return AE_OK;

        if (status == AE_NOT_FOUND) {
                *sta = ACPI_STA_DEVICE_PRESENT | ACPI_STA_DEVICE_ENABLED |
                       ACPI_STA_DEVICE_UI      | ACPI_STA_DEVICE_FUNCTIONING;
                return AE_OK;
        }
        return status;
}

int acpi_bus_get_status(struct acpi_device *device)
{
        acpi_status status;
        unsigned long long sta;

        if (acpi_device_always_present(device)) {
                acpi_set_device_status(device, ACPI_STA_DEFAULT);
                return 0;
        }

        status = acpi_bus_get_status_handle(device->handle, &sta);
        if (ACPI_FAILURE(status))
                return -ENODEV;

        acpi_set_device_status(device, sta);

        if (device->status.functional && !device->status.present) {
                ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] status [%08x]: "
                       "functional but not present;\n",
                        device->pnp.bus_id, (u32)sta));
        }

        ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] status [%08x]\n",
                          device->pnp.bus_id, (u32)sta));
        return 0;
}
EXPORT_SYMBOL(acpi_bus_get_status);

void acpi_bus_private_data_handler(acpi_handle handle,
                                   void *context)
{
        return;
}
EXPORT_SYMBOL(acpi_bus_private_data_handler);

int acpi_bus_attach_private_data(acpi_handle handle, void *data)
{
        acpi_status status;

        status = acpi_attach_data(handle,
                        acpi_bus_private_data_handler, data);
        if (ACPI_FAILURE(status)) {
                acpi_handle_debug(handle, "Error attaching device data\n");
                return -ENODEV;
        }

        return 0;
}
EXPORT_SYMBOL_GPL(acpi_bus_attach_private_data);

int acpi_bus_get_private_data(acpi_handle handle, void **data)
{
        acpi_status status;

        if (!*data)
                return -EINVAL;

        status = acpi_get_data(handle, acpi_bus_private_data_handler, data);
        if (ACPI_FAILURE(status)) {
                acpi_handle_debug(handle, "No context for object\n");
                return -ENODEV;
        }

        return 0;
}
EXPORT_SYMBOL_GPL(acpi_bus_get_private_data);

void acpi_bus_detach_private_data(acpi_handle handle)
{
        acpi_detach_data(handle, acpi_bus_private_data_handler);
}
EXPORT_SYMBOL_GPL(acpi_bus_detach_private_data);

static void acpi_print_osc_error(acpi_handle handle,
                                 struct acpi_osc_context *context, char *error)
{
        int i;

        acpi_handle_debug(handle, "(%s): %s\n", context->uuid_str, error);

        pr_debug("_OSC request data:");
        for (i = 0; i < context->cap.length; i += sizeof(u32))
                pr_debug(" %x", *((u32 *)(context->cap.pointer + i)));

        pr_debug("\n");
}

acpi_status acpi_str_to_uuid(char *str, u8 *uuid)
{
        int i;
        static int opc_map_to_uuid[16] = {6, 4, 2, 0, 11, 9, 16, 14, 19, 21,
                24, 26, 28, 30, 32, 34};

        if (strlen(str) != 36)
                return AE_BAD_PARAMETER;
        for (i = 0; i < 36; i++) {
                if (i == 8 || i == 13 || i == 18 || i == 23) {
                        if (str[i] != '-')
                                return AE_BAD_PARAMETER;
                } else if (!isxdigit(str[i]))
                        return AE_BAD_PARAMETER;
        }
        for (i = 0; i < 16; i++) {
                uuid[i] = hex_to_bin(str[opc_map_to_uuid[i]]) << 4;
                uuid[i] |= hex_to_bin(str[opc_map_to_uuid[i] + 1]);
        }
        return AE_OK;
}
EXPORT_SYMBOL_GPL(acpi_str_to_uuid);

acpi_status acpi_run_osc(acpi_handle handle, struct acpi_osc_context *context)
{
        acpi_status status;
        struct acpi_object_list input;
        union acpi_object in_params[4];
        union acpi_object *out_obj;
        u8 uuid[16];
        u32 errors;
        struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL};

        if (!context)
                return AE_ERROR;
        if (ACPI_FAILURE(acpi_str_to_uuid(context->uuid_str, uuid)))
                return AE_ERROR;
        context->ret.length = ACPI_ALLOCATE_BUFFER;
        context->ret.pointer = NULL;

        /* Setting up input parameters */
        input.count = 4;
        input.pointer = in_params;
        in_params[0].type               = ACPI_TYPE_BUFFER;
        in_params[0].buffer.length      = 16;
        in_params[0].buffer.pointer     = uuid;
        in_params[1].type               = ACPI_TYPE_INTEGER;
        in_params[1].integer.value      = context->rev;
        in_params[2].type               = ACPI_TYPE_INTEGER;
        in_params[2].integer.value      = context->cap.length/sizeof(u32);
        in_params[3].type               = ACPI_TYPE_BUFFER;
        in_params[3].buffer.length      = context->cap.length;
        in_params[3].buffer.pointer     = context->cap.pointer;

        status = acpi_evaluate_object(handle, "_OSC", &input, &output);
        if (ACPI_FAILURE(status))
                return status;

        if (!output.length)
                return AE_NULL_OBJECT;

        out_obj = output.pointer;
        if (out_obj->type != ACPI_TYPE_BUFFER
                || out_obj->buffer.length != context->cap.length) {
                acpi_print_osc_error(handle, context,
                        "_OSC evaluation returned wrong type");
                status = AE_TYPE;
                goto out_kfree;
        }
        /* Need to ignore the bit0 in result code */
        errors = *((u32 *)out_obj->buffer.pointer) & ~(1 << 0);
        if (errors) {
                if (errors & OSC_REQUEST_ERROR)
                        acpi_print_osc_error(handle, context,
                                "_OSC request failed");
                if (errors & OSC_INVALID_UUID_ERROR)
                        acpi_print_osc_error(handle, context,
                                "_OSC invalid UUID");
                if (errors & OSC_INVALID_REVISION_ERROR)
                        acpi_print_osc_error(handle, context,
                                "_OSC invalid revision");
                if (errors & OSC_CAPABILITIES_MASK_ERROR) {
                        if (((u32 *)context->cap.pointer)[OSC_QUERY_DWORD]
                            & OSC_QUERY_ENABLE)
                                goto out_success;
                        status = AE_SUPPORT;
                        goto out_kfree;
                }
                status = AE_ERROR;
                goto out_kfree;
        }
out_success:
        context->ret.length = out_obj->buffer.length;
        context->ret.pointer = kmemdup(out_obj->buffer.pointer,
                                       context->ret.length, GFP_KERNEL);
        if (!context->ret.pointer) {
                status =  AE_NO_MEMORY;
                goto out_kfree;
        }
        status =  AE_OK;

out_kfree:
        kfree(output.pointer);
        if (status != AE_OK)
                context->ret.pointer = NULL;
        return status;
}
EXPORT_SYMBOL(acpi_run_osc);

bool osc_sb_apei_support_acked;

/*
 * ACPI 6.0 Section 8.4.4.2 Idle State Coordination
 * OSPM supports platform coordinated low power idle(LPI) states
 */
bool osc_pc_lpi_support_confirmed;
EXPORT_SYMBOL_GPL(osc_pc_lpi_support_confirmed);

static u8 sb_uuid_str[] = "0811B06E-4A27-44F9-8D60-3CBBC22E7B48";
static void acpi_bus_osc_support(void)
{
        u32 capbuf[2];
        struct acpi_osc_context context = {
                .uuid_str = sb_uuid_str,
                .rev = 1,
                .cap.length = 8,
                .cap.pointer = capbuf,
        };
        acpi_handle handle;

        capbuf[OSC_QUERY_DWORD] = OSC_QUERY_ENABLE;
        capbuf[OSC_SUPPORT_DWORD] = OSC_SB_PR3_SUPPORT; /* _PR3 is in use */
        if (IS_ENABLED(CONFIG_ACPI_PROCESSOR_AGGREGATOR))
                capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_PAD_SUPPORT;
        if (IS_ENABLED(CONFIG_ACPI_PROCESSOR))
                capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_PPC_OST_SUPPORT;

        capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_HOTPLUG_OST_SUPPORT;
        capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_PCLPI_SUPPORT;

#ifdef CONFIG_X86
        if (boot_cpu_has(X86_FEATURE_HWP)) {
                capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_CPC_SUPPORT;
                capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_CPCV2_SUPPORT;
        }
#endif

        if (IS_ENABLED(CONFIG_SCHED_MC_PRIO))
                capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_CPC_DIVERSE_HIGH_SUPPORT;

        if (!ghes_disable)
                capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_APEI_SUPPORT;
        if (ACPI_FAILURE(acpi_get_handle(NULL, "\\_SB", &handle)))
                return;
        if (ACPI_SUCCESS(acpi_run_osc(handle, &context))) {
                u32 *capbuf_ret = context.ret.pointer;
                if (context.ret.length > OSC_SUPPORT_DWORD) {
                        osc_sb_apei_support_acked =
                                capbuf_ret[OSC_SUPPORT_DWORD] & OSC_SB_APEI_SUPPORT;
                        osc_pc_lpi_support_confirmed =
                                capbuf_ret[OSC_SUPPORT_DWORD] & OSC_SB_PCLPI_SUPPORT;
                }
                kfree(context.ret.pointer);
        }
        /* do we need to check other returned cap? Sounds no */
}

/* --------------------------------------------------------------------------
                             Notification Handling
   -------------------------------------------------------------------------- */

/**
 * acpi_bus_notify
 * ---------------
 * Callback for all 'system-level' device notifications (values 0x00-0x7F).
 */
static void acpi_bus_notify(acpi_handle handle, u32 type, void *data)
{
        struct acpi_device *adev;
        struct acpi_driver *driver;
        u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE;
        bool hotplug_event = false;

        switch (type) {
        case ACPI_NOTIFY_BUS_CHECK:
                acpi_handle_debug(handle, "ACPI_NOTIFY_BUS_CHECK event\n");
                hotplug_event = true;
                break;

        case ACPI_NOTIFY_DEVICE_CHECK:
                acpi_handle_debug(handle, "ACPI_NOTIFY_DEVICE_CHECK event\n");
                hotplug_event = true;
                break;

        case ACPI_NOTIFY_DEVICE_WAKE:
                acpi_handle_debug(handle, "ACPI_NOTIFY_DEVICE_WAKE event\n");
                break;

        case ACPI_NOTIFY_EJECT_REQUEST:
                acpi_handle_debug(handle, "ACPI_NOTIFY_EJECT_REQUEST event\n");
                hotplug_event = true;
                break;

        case ACPI_NOTIFY_DEVICE_CHECK_LIGHT:
                acpi_handle_debug(handle, "ACPI_NOTIFY_DEVICE_CHECK_LIGHT event\n");
                /* TBD: Exactly what does 'light' mean? */
                break;

        case ACPI_NOTIFY_FREQUENCY_MISMATCH:
                acpi_handle_err(handle, "Device cannot be configured due "
                                "to a frequency mismatch\n");
                break;

        case ACPI_NOTIFY_BUS_MODE_MISMATCH:
                acpi_handle_err(handle, "Device cannot be configured due "
                                "to a bus mode mismatch\n");
                break;

        case ACPI_NOTIFY_POWER_FAULT:
                acpi_handle_err(handle, "Device has suffered a power fault\n");
                break;

        default:
                acpi_handle_debug(handle, "Unknown event type 0x%x\n", type);
                break;
        }

        adev = acpi_bus_get_acpi_device(handle);
        if (!adev)
                goto err;

        driver = adev->driver;
        if (driver && driver->ops.notify &&
            (driver->flags & ACPI_DRIVER_ALL_NOTIFY_EVENTS))
                driver->ops.notify(adev, type);

        if (hotplug_event && ACPI_SUCCESS(acpi_hotplug_schedule(adev, type)))
                return;

        acpi_bus_put_acpi_device(adev);
        return;

 err:
        acpi_evaluate_ost(handle, type, ost_code, NULL);
}

static void acpi_device_notify(acpi_handle handle, u32 event, void *data)
{
        struct acpi_device *device = data;

        device->driver->ops.notify(device, event);
}

static void acpi_device_notify_fixed(void *data)
{
        struct acpi_device *device = data;

        /* Fixed hardware devices have no handles */
        acpi_device_notify(NULL, ACPI_FIXED_HARDWARE_EVENT, device);
}

static u32 acpi_device_fixed_event(void *data)
{
        acpi_os_execute(OSL_NOTIFY_HANDLER, acpi_device_notify_fixed, data);
        return ACPI_INTERRUPT_HANDLED;
}

static int acpi_device_install_notify_handler(struct acpi_device *device)
{
        acpi_status status;

        if (device->device_type == ACPI_BUS_TYPE_POWER_BUTTON)
                status =
                    acpi_install_fixed_event_handler(ACPI_EVENT_POWER_BUTTON,
                                                     acpi_device_fixed_event,
                                                     device);
        else if (device->device_type == ACPI_BUS_TYPE_SLEEP_BUTTON)
                status =
                    acpi_install_fixed_event_handler(ACPI_EVENT_SLEEP_BUTTON,
                                                     acpi_device_fixed_event,
                                                     device);
        else
                status = acpi_install_notify_handler(device->handle,
                                                     ACPI_DEVICE_NOTIFY,
                                                     acpi_device_notify,
                                                     device);

        if (ACPI_FAILURE(status))
                return -EINVAL;
        return 0;
}

static void acpi_device_remove_notify_handler(struct acpi_device *device)
{
        if (device->device_type == ACPI_BUS_TYPE_POWER_BUTTON)
                acpi_remove_fixed_event_handler(ACPI_EVENT_POWER_BUTTON,
                                                acpi_device_fixed_event);
        else if (device->device_type == ACPI_BUS_TYPE_SLEEP_BUTTON)
                acpi_remove_fixed_event_handler(ACPI_EVENT_SLEEP_BUTTON,
                                                acpi_device_fixed_event);
        else
                acpi_remove_notify_handler(device->handle, ACPI_DEVICE_NOTIFY,
                                           acpi_device_notify);
}

/* Handle events targeting \_SB device (at present only graceful shutdown) */

#define ACPI_SB_NOTIFY_SHUTDOWN_REQUEST 0x81
#define ACPI_SB_INDICATE_INTERVAL       10000

static void sb_notify_work(struct work_struct *dummy)
{
        acpi_handle sb_handle;

        orderly_poweroff(true);

        /*
         * After initiating graceful shutdown, the ACPI spec requires OSPM
         * to evaluate _OST method once every 10seconds to indicate that
         * the shutdown is in progress
         */
        acpi_get_handle(NULL, "\\_SB", &sb_handle);
        while (1) {
                pr_info("Graceful shutdown in progress.\n");
                acpi_evaluate_ost(sb_handle, ACPI_OST_EC_OSPM_SHUTDOWN,
                                ACPI_OST_SC_OS_SHUTDOWN_IN_PROGRESS, NULL);
                msleep(ACPI_SB_INDICATE_INTERVAL);
        }
}

static void acpi_sb_notify(acpi_handle handle, u32 event, void *data)
{
        static DECLARE_WORK(acpi_sb_work, sb_notify_work);

        if (event == ACPI_SB_NOTIFY_SHUTDOWN_REQUEST) {
                if (!work_busy(&acpi_sb_work))
                        schedule_work(&acpi_sb_work);
        } else
                pr_warn("event %x is not supported by \\_SB device\n", event);
}

static int __init acpi_setup_sb_notify_handler(void)
{
        acpi_handle sb_handle;

        if (ACPI_FAILURE(acpi_get_handle(NULL, "\\_SB", &sb_handle)))
                return -ENXIO;

        if (ACPI_FAILURE(acpi_install_notify_handler(sb_handle, ACPI_DEVICE_NOTIFY,
                                                acpi_sb_notify, NULL)))
                return -EINVAL;

        return 0;
}

/* --------------------------------------------------------------------------
                             Device Matching
   -------------------------------------------------------------------------- */

/**
 * acpi_get_first_physical_node - Get first physical node of an ACPI device
 * @adev:       ACPI device in question
 *
 * Return: First physical node of ACPI device @adev
 */
struct device *acpi_get_first_physical_node(struct acpi_device *adev)
{
        struct mutex *physical_node_lock = &adev->physical_node_lock;
        struct device *phys_dev;

        mutex_lock(physical_node_lock);
        if (list_empty(&adev->physical_node_list)) {
                phys_dev = NULL;
        } else {
                const struct acpi_device_physical_node *node;

                node = list_first_entry(&adev->physical_node_list,
                                        struct acpi_device_physical_node, node);

                phys_dev = node->dev;
        }
        mutex_unlock(physical_node_lock);
        return phys_dev;
}

static struct acpi_device *acpi_primary_dev_companion(struct acpi_device *adev,
                                                      const struct device *dev)
{
        const struct device *phys_dev = acpi_get_first_physical_node(adev);

        return phys_dev && phys_dev == dev ? adev : NULL;
}

/**
 * acpi_device_is_first_physical_node - Is given dev first physical node
 * @adev: ACPI companion device
 * @dev: Physical device to check
 *
 * Function checks if given @dev is the first physical devices attached to
 * the ACPI companion device. This distinction is needed in some cases
 * where the same companion device is shared between many physical devices.
 *
 * Note that the caller have to provide valid @adev pointer.
 */
bool acpi_device_is_first_physical_node(struct acpi_device *adev,
                                        const struct device *dev)
{
        return !!acpi_primary_dev_companion(adev, dev);
}

/*
 * acpi_companion_match() - Can we match via ACPI companion device
 * @dev: Device in question
 *
 * Check if the given device has an ACPI companion and if that companion has
 * a valid list of PNP IDs, and if the device is the first (primary) physical
 * device associated with it.  Return the companion pointer if that's the case
 * or NULL otherwise.
 *
 * If multiple physical devices are attached to a single ACPI companion, we need
 * to be careful.  The usage scenario for this kind of relationship is that all
 * of the physical devices in question use resources provided by the ACPI
 * companion.  A typical case is an MFD device where all the sub-devices share
 * the parent's ACPI companion.  In such cases we can only allow the primary
 * (first) physical device to be matched with the help of the companion's PNP
 * IDs.
 *
 * Additional physical devices sharing the ACPI companion can still use
 * resources available from it but they will be matched normally using functions
 * provided by their bus types (and analogously for their modalias).
 */
struct acpi_device *acpi_companion_match(const struct device *dev)
{
        struct acpi_device *adev;

        adev = ACPI_COMPANION(dev);
        if (!adev)
                return NULL;

        if (list_empty(&adev->pnp.ids))
                return NULL;

        return acpi_primary_dev_companion(adev, dev);
}

/**
 * acpi_of_match_device - Match device object using the "compatible" property.
 * @adev: ACPI device object to match.
 * @of_match_table: List of device IDs to match against.
 *
 * If @dev has an ACPI companion which has ACPI_DT_NAMESPACE_HID in its list of
 * identifiers and a _DSD object with the "compatible" property, use that
 * property to match against the given list of identifiers.
 */
static bool acpi_of_match_device(struct acpi_device *adev,
                                 const struct of_device_id *of_match_table)
{
        const union acpi_object *of_compatible, *obj;
        int i, nval;

        if (!adev)
                return false;

        of_compatible = adev->data.of_compatible;
        if (!of_match_table || !of_compatible)
                return false;

        if (of_compatible->type == ACPI_TYPE_PACKAGE) {
                nval = of_compatible->package.count;
                obj = of_compatible->package.elements;
        } else { /* Must be ACPI_TYPE_STRING. */
                nval = 1;
                obj = of_compatible;
        }
        /* Now we can look for the driver DT compatible strings */
        for (i = 0; i < nval; i++, obj++) {
                const struct of_device_id *id;

                for (id = of_match_table; id->compatible[0]; id++)
                        if (!strcasecmp(obj->string.pointer, id->compatible))
                                return true;
        }

        return false;
}

static bool acpi_of_modalias(struct acpi_device *adev,
                             char *modalias, size_t len)
{
        const union acpi_object *of_compatible;
        const union acpi_object *obj;
        const char *str, *chr;

        of_compatible = adev->data.of_compatible;
        if (!of_compatible)
                return false;

        if (of_compatible->type == ACPI_TYPE_PACKAGE)
                obj = of_compatible->package.elements;
        else /* Must be ACPI_TYPE_STRING. */
                obj = of_compatible;

        str = obj->string.pointer;
        chr = strchr(str, ',');
        strlcpy(modalias, chr ? chr + 1 : str, len);

        return true;
}

/**
 * acpi_set_modalias - Set modalias using "compatible" property or supplied ID
 * @adev:       ACPI device object to match
 * @default_id: ID string to use as default if no compatible string found
 * @modalias:   Pointer to buffer that modalias value will be copied into
 * @len:        Length of modalias buffer
 *
 * This is a counterpart of of_modalias_node() for struct acpi_device objects.
 * If there is a compatible string for @adev, it will be copied to @modalias
 * with the vendor prefix stripped; otherwise, @default_id will be used.
 */
void acpi_set_modalias(struct acpi_device *adev, const char *default_id,
                       char *modalias, size_t len)
{
        if (!acpi_of_modalias(adev, modalias, len))
                strlcpy(modalias, default_id, len);
}
EXPORT_SYMBOL_GPL(acpi_set_modalias);

static bool __acpi_match_device_cls(const struct acpi_device_id *id,
                                    struct acpi_hardware_id *hwid)
{
        int i, msk, byte_shift;
        char buf[3];

        if (!id->cls)
                return false;

        /* Apply class-code bitmask, before checking each class-code byte */
        for (i = 1; i <= 3; i++) {
                byte_shift = 8 * (3 - i);
                msk = (id->cls_msk >> byte_shift) & 0xFF;
                if (!msk)
                        continue;

                sprintf(buf, "%02x", (id->cls >> byte_shift) & msk);
                if (strncmp(buf, &hwid->id[(i - 1) * 2], 2))
                        return false;
        }
        return true;
}

static const struct acpi_device_id *__acpi_match_device(
        struct acpi_device *device,
        const struct acpi_device_id *ids,
        const struct of_device_id *of_ids)
{
        const struct acpi_device_id *id;
        struct acpi_hardware_id *hwid;

        /*
         * If the device is not present, it is unnecessary to load device
         * driver for it.
         */
        if (!device || !device->status.present)
                return NULL;

        list_for_each_entry(hwid, &device->pnp.ids, list) {
                /* First, check the ACPI/PNP IDs provided by the caller. */
                for (id = ids; id->id[0] || id->cls; id++) {
                        if (id->id[0] && !strcmp((char *) id->id, hwid->id))
                                return id;
                        else if (id->cls && __acpi_match_device_cls(id, hwid))
                                return id;
                }

                /*
                 * Next, check ACPI_DT_NAMESPACE_HID and try to match the
                 * "compatible" property if found.
                 *
                 * The id returned by the below is not valid, but the only
                 * caller passing non-NULL of_ids here is only interested in
                 * whether or not the return value is NULL.
                 */
                if (!strcmp(ACPI_DT_NAMESPACE_HID, hwid->id)
                    && acpi_of_match_device(device, of_ids))
                        return id;
        }
        return NULL;
}

/**
 * acpi_match_device - Match a struct device against a given list of ACPI IDs
 * @ids: Array of struct acpi_device_id object to match against.
 * @dev: The device structure to match.
 *
 * Check if @dev has a valid ACPI handle and if there is a struct acpi_device
 * object for that handle and use that object to match against a given list of
 * device IDs.
 *
 * Return a pointer to the first matching ID on success or %NULL on failure.
 */
const struct acpi_device_id *acpi_match_device(const struct acpi_device_id *ids,
                                               const struct device *dev)
{
        return __acpi_match_device(acpi_companion_match(dev), ids, NULL);
}
EXPORT_SYMBOL_GPL(acpi_match_device);

int acpi_match_device_ids(struct acpi_device *device,
                          const struct acpi_device_id *ids)
{
        return __acpi_match_device(device, ids, NULL) ? 0 : -ENOENT;
}
EXPORT_SYMBOL(acpi_match_device_ids);

bool acpi_driver_match_device(struct device *dev,
                              const struct device_driver *drv)
{
        if (!drv->acpi_match_table)
                return acpi_of_match_device(ACPI_COMPANION(dev),
                                            drv->of_match_table);

        return !!__acpi_match_device(acpi_companion_match(dev),
                                     drv->acpi_match_table, drv->of_match_table);
}
EXPORT_SYMBOL_GPL(acpi_driver_match_device);

/* --------------------------------------------------------------------------
                              ACPI Driver Management
   -------------------------------------------------------------------------- */

/**
 * acpi_bus_register_driver - register a driver with the ACPI bus
 * @driver: driver being registered
 *
 * Registers a driver with the ACPI bus.  Searches the namespace for all
 * devices that match the driver's criteria and binds.  Returns zero for
 * success or a negative error status for failure.
 */
int acpi_bus_register_driver(struct acpi_driver *driver)
{
        int ret;

        if (acpi_disabled)
                return -ENODEV;
        driver->drv.name = driver->name;
        driver->drv.bus = &acpi_bus_type;
        driver->drv.owner = driver->owner;

        ret = driver_register(&driver->drv);
        return ret;
}

EXPORT_SYMBOL(acpi_bus_register_driver);

/**
 * acpi_bus_unregister_driver - unregisters a driver with the ACPI bus
 * @driver: driver to unregister
 *
 * Unregisters a driver with the ACPI bus.  Searches the namespace for all
 * devices that match the driver's criteria and unbinds.
 */
void acpi_bus_unregister_driver(struct acpi_driver *driver)
{
        driver_unregister(&driver->drv);
}

EXPORT_SYMBOL(acpi_bus_unregister_driver);

/* --------------------------------------------------------------------------
                              ACPI Bus operations
   -------------------------------------------------------------------------- */

static int acpi_bus_match(struct device *dev, struct device_driver *drv)
{
        struct acpi_device *acpi_dev = to_acpi_device(dev);
        struct acpi_driver *acpi_drv = to_acpi_driver(drv);

        return acpi_dev->flags.match_driver
                && !acpi_match_device_ids(acpi_dev, acpi_drv->ids);
}

static int acpi_device_uevent(struct device *dev, struct kobj_uevent_env *env)
{
        return __acpi_device_uevent_modalias(to_acpi_device(dev), env);
}

static int acpi_device_probe(struct device *dev)
{
        struct acpi_device *acpi_dev = to_acpi_device(dev);
        struct acpi_driver *acpi_drv = to_acpi_driver(dev->driver);
        int ret;

        if (acpi_dev->handler && !acpi_is_pnp_device(acpi_dev))
                return -EINVAL;

        if (!acpi_drv->ops.add)
                return -ENOSYS;

        ret = acpi_drv->ops.add(acpi_dev);
        if (ret)
                return ret;

        acpi_dev->driver = acpi_drv;
        ACPI_DEBUG_PRINT((ACPI_DB_INFO,
                          "Driver [%s] successfully bound to device [%s]\n",
                          acpi_drv->name, acpi_dev->pnp.bus_id));

        if (acpi_drv->ops.notify) {
                ret = acpi_device_install_notify_handler(acpi_dev);
                if (ret) {
                        if (acpi_drv->ops.remove)
                                acpi_drv->ops.remove(acpi_dev);

                        acpi_dev->driver = NULL;
                        acpi_dev->driver_data = NULL;
                        return ret;
                }
        }

        ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found driver [%s] for device [%s]\n",
                          acpi_drv->name, acpi_dev->pnp.bus_id));
        get_device(dev);
        return 0;
}

static int acpi_device_remove(struct device * dev)
{
        struct acpi_device *acpi_dev = to_acpi_device(dev);
        struct acpi_driver *acpi_drv = acpi_dev->driver;

        if (acpi_drv) {
                if (acpi_drv->ops.notify)
                        acpi_device_remove_notify_handler(acpi_dev);
                if (acpi_drv->ops.remove)
                        acpi_drv->ops.remove(acpi_dev);
        }
        acpi_dev->driver = NULL;
        acpi_dev->driver_data = NULL;

        put_device(dev);
        return 0;
}

struct bus_type acpi_bus_type = {
        .name           = "acpi",
        .match          = acpi_bus_match,
        .probe          = acpi_device_probe,
        .remove         = acpi_device_remove,
        .uevent         = acpi_device_uevent,
};

/* --------------------------------------------------------------------------
                             Initialization/Cleanup
   -------------------------------------------------------------------------- */

static int __init acpi_bus_init_irq(void)
{
        acpi_status status;
        char *message = NULL;


        /*
         * Let the system know what interrupt model we are using by
         * evaluating the \_PIC object, if exists.
         */

        switch (acpi_irq_model) {
        case ACPI_IRQ_MODEL_PIC:
                message = "PIC";
                break;
        case ACPI_IRQ_MODEL_IOAPIC:
                message = "IOAPIC";
                break;
        case ACPI_IRQ_MODEL_IOSAPIC:
                message = "IOSAPIC";
                break;
        case ACPI_IRQ_MODEL_GIC:
                message = "GIC";
                break;
        case ACPI_IRQ_MODEL_PLATFORM:
                message = "platform specific model";
                break;
        default:
                printk(KERN_WARNING PREFIX "Unknown interrupt routing model\n");
                return -ENODEV;
        }

        printk(KERN_INFO PREFIX "Using %s for interrupt routing\n", message);

        status = acpi_execute_simple_method(NULL, "\\_PIC", acpi_irq_model);
        if (ACPI_FAILURE(status) && (status != AE_NOT_FOUND)) {
                ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PIC"));
                return -ENODEV;
        }

        return 0;
}

/**
 * acpi_early_init - Initialize ACPICA and populate the ACPI namespace.
 *
 * The ACPI tables are accessible after this, but the handling of events has not
 * been initialized and the global lock is not available yet, so AML should not
 * be executed at this point.
 *
 * Doing this before switching the EFI runtime services to virtual mode allows
 * the EfiBootServices memory to be freed slightly earlier on boot.
 */
void __init acpi_early_init(void)
{
        acpi_status status;

        if (acpi_disabled)
                return;

        printk(KERN_INFO PREFIX "Core revision %08x\n", ACPI_CA_VERSION);

        /* It's safe to verify table checksums during late stage */
        acpi_gbl_verify_table_checksum = TRUE;

        /* enable workarounds, unless strict ACPI spec. compliance */
        if (!acpi_strict)
                acpi_gbl_enable_interpreter_slack = TRUE;

        acpi_permanent_mmap = true;

        /*
         * If the machine falls into the DMI check table,
         * DSDT will be copied to memory
         */
        dmi_check_system(dsdt_dmi_table);

        status = acpi_reallocate_root_table();
        if (ACPI_FAILURE(status)) {
                printk(KERN_ERR PREFIX
                       "Unable to reallocate ACPI tables\n");
                goto error0;
        }

        status = acpi_initialize_subsystem();
        if (ACPI_FAILURE(status)) {
                printk(KERN_ERR PREFIX
                       "Unable to initialize the ACPI Interpreter\n");
                goto error0;
        }

        if (!acpi_gbl_parse_table_as_term_list &&
            acpi_gbl_group_module_level_code) {
                status = acpi_load_tables();
                if (ACPI_FAILURE(status)) {
                        printk(KERN_ERR PREFIX
                               "Unable to load the System Description Tables\n");
                        goto error0;
                }
        }

#ifdef CONFIG_X86
        if (!acpi_ioapic) {
                /* compatible (0) means level (3) */
                if (!(acpi_sci_flags & ACPI_MADT_TRIGGER_MASK)) {
                        acpi_sci_flags &= ~ACPI_MADT_TRIGGER_MASK;
                        acpi_sci_flags |= ACPI_MADT_TRIGGER_LEVEL;
                }
                /* Set PIC-mode SCI trigger type */
                acpi_pic_sci_set_trigger(acpi_gbl_FADT.sci_interrupt,
                                         (acpi_sci_flags & ACPI_MADT_TRIGGER_MASK) >> 2);
        } else {
                /*
                 * now that acpi_gbl_FADT is initialized,
                 * update it with result from INT_SRC_OVR parsing
                 */
                acpi_gbl_FADT.sci_interrupt = acpi_sci_override_gsi;
        }
#endif
        return;

 error0:
        disable_acpi();
}

/**
 * acpi_subsystem_init - Finalize the early initialization of ACPI.
 *
 * Switch over the platform to the ACPI mode (if possible).
 *
 * Doing this too early is generally unsafe, but at the same time it needs to be
 * done before all things that really depend on ACPI.  The right spot appears to
 * be before finalizing the EFI initialization.
 */
void __init acpi_subsystem_init(void)
{
        acpi_status status;

        if (acpi_disabled)
                return;

        status = acpi_enable_subsystem(~ACPI_NO_ACPI_ENABLE);
        if (ACPI_FAILURE(status)) {
                printk(KERN_ERR PREFIX "Unable to enable ACPI\n");
                disable_acpi();
        } else {
                /*
                 * If the system is using ACPI then we can be reasonably
                 * confident that any regulators are managed by the firmware
                 * so tell the regulator core it has everything it needs to
                 * know.
                 */
                regulator_has_full_constraints();
        }
}

static acpi_status acpi_bus_table_handler(u32 event, void *table, void *context)
{
        acpi_scan_table_handler(event, table, context);

        return acpi_sysfs_table_handler(event, table, context);
}

static int __init acpi_bus_init(void)
{
        int result;
        acpi_status status;

        acpi_os_initialize1();

        /*
         * ACPI 2.0 requires the EC driver to be loaded and work before
         * the EC device is found in the namespace (i.e. before
         * acpi_load_tables() is called).
         *
         * This is accomplished by looking for the ECDT table, and getting
         * the EC parameters out of that.
         */
        status = acpi_ec_ecdt_probe();
        /* Ignore result. Not having an ECDT is not fatal. */

        if (acpi_gbl_parse_table_as_term_list ||
            !acpi_gbl_group_module_level_code) {
                status = acpi_load_tables();
                if (ACPI_FAILURE(status)) {
                        printk(KERN_ERR PREFIX
                               "Unable to load the System Description Tables\n");
                        goto error1;
                }
        }

        status = acpi_enable_subsystem(ACPI_NO_ACPI_ENABLE);
        if (ACPI_FAILURE(status)) {
                printk(KERN_ERR PREFIX
                       "Unable to start the ACPI Interpreter\n");
                goto error1;
        }

        status = acpi_initialize_objects(ACPI_FULL_INITIALIZATION);
        if (ACPI_FAILURE(status)) {
                printk(KERN_ERR PREFIX "Unable to initialize ACPI objects\n");
                goto error1;
        }

        /* Set capability bits for _OSC under processor scope */
        acpi_early_processor_osc();

        /*
         * _OSC method may exist in module level code,
         * so it must be run after ACPI_FULL_INITIALIZATION
         */
        acpi_bus_osc_support();

        /*
         * _PDC control method may load dynamic SSDT tables,
         * and we need to install the table handler before that.
         */
        status = acpi_install_table_handler(acpi_bus_table_handler, NULL);

        acpi_sysfs_init();

        acpi_early_processor_set_pdc();

        /*
         * Maybe EC region is required at bus_scan/acpi_get_devices. So it
         * is necessary to enable it as early as possible.
         */
        acpi_ec_dsdt_probe();

        printk(KERN_INFO PREFIX "Interpreter enabled\n");

        /* Initialize sleep structures */
        acpi_sleep_init();

        /*
         * Get the system interrupt model and evaluate \_PIC.
         */
        result = acpi_bus_init_irq();
        if (result)
                goto error1;

        /*
         * Register the for all standard device notifications.
         */
        status =
            acpi_install_notify_handler(ACPI_ROOT_OBJECT, ACPI_SYSTEM_NOTIFY,
                                        &acpi_bus_notify, NULL);
        if (ACPI_FAILURE(status)) {
                printk(KERN_ERR PREFIX
                       "Unable to register for device notifications\n");
                goto error1;
        }

        /*
         * Create the top ACPI proc directory
         */
        acpi_root_dir = proc_mkdir(ACPI_BUS_FILE_ROOT, NULL);

        result = bus_register(&acpi_bus_type);
        if (!result)
                return 0;

        /* Mimic structured exception handling */
      error1:
        acpi_terminate();
        return -ENODEV;
}

struct kobject *acpi_kobj;
EXPORT_SYMBOL_GPL(acpi_kobj);

static int __init acpi_init(void)
{
        int result;

        if (acpi_disabled) {
                printk(KERN_INFO PREFIX "Interpreter disabled.\n");
                return -ENODEV;
        }

        acpi_kobj = kobject_create_and_add("acpi", firmware_kobj);
        if (!acpi_kobj) {
                printk(KERN_WARNING "%s: kset create error\n", __func__);
                acpi_kobj = NULL;
        }

        init_acpi_device_notify();
        result = acpi_bus_init();
        if (result) {
                disable_acpi();
                return result;
        }

        pci_mmcfg_late_init();
        acpi_iort_init();
        acpi_scan_init();
        acpi_ec_init();
        acpi_debugfs_init();
        acpi_sleep_proc_init();
        acpi_wakeup_device_init();
        acpi_debugger_init();
        acpi_setup_sb_notify_handler();
        return 0;
}

subsys_initcall(acpi_init);