281 lines
6.8 KiB
C
281 lines
6.8 KiB
C
/*
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* WMI methods for use with dell-smbios
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*
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* Copyright (c) 2017 Dell Inc.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/dmi.h>
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#include <linux/list.h>
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#include <linux/module.h>
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#include <linux/mutex.h>
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#include <linux/uaccess.h>
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#include <linux/wmi.h>
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#include "dell-smbios.h"
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#include "dell-wmi-descriptor.h"
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static DEFINE_MUTEX(call_mutex);
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static DEFINE_MUTEX(list_mutex);
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static int wmi_supported;
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struct misc_bios_flags_structure {
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struct dmi_header header;
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u16 flags0;
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} __packed;
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#define FLAG_HAS_ACPI_WMI 0x02
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#define DELL_WMI_SMBIOS_GUID "A80593CE-A997-11DA-B012-B622A1EF5492"
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struct wmi_smbios_priv {
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struct dell_wmi_smbios_buffer *buf;
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struct list_head list;
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struct wmi_device *wdev;
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struct device *child;
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u32 req_buf_size;
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};
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static LIST_HEAD(wmi_list);
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static inline struct wmi_smbios_priv *get_first_smbios_priv(void)
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{
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return list_first_entry_or_null(&wmi_list,
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struct wmi_smbios_priv,
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list);
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}
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static int run_smbios_call(struct wmi_device *wdev)
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{
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struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL};
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struct wmi_smbios_priv *priv;
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struct acpi_buffer input;
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union acpi_object *obj;
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acpi_status status;
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priv = dev_get_drvdata(&wdev->dev);
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input.length = priv->req_buf_size - sizeof(u64);
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input.pointer = &priv->buf->std;
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dev_dbg(&wdev->dev, "evaluating: %u/%u [%x,%x,%x,%x]\n",
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priv->buf->std.cmd_class, priv->buf->std.cmd_select,
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priv->buf->std.input[0], priv->buf->std.input[1],
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priv->buf->std.input[2], priv->buf->std.input[3]);
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status = wmidev_evaluate_method(wdev, 0, 1, &input, &output);
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if (ACPI_FAILURE(status))
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return -EIO;
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obj = (union acpi_object *)output.pointer;
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if (obj->type != ACPI_TYPE_BUFFER) {
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dev_dbg(&wdev->dev, "received type: %d\n", obj->type);
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if (obj->type == ACPI_TYPE_INTEGER)
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dev_dbg(&wdev->dev, "SMBIOS call failed: %llu\n",
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obj->integer.value);
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return -EIO;
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}
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memcpy(&priv->buf->std, obj->buffer.pointer, obj->buffer.length);
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dev_dbg(&wdev->dev, "result: [%08x,%08x,%08x,%08x]\n",
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priv->buf->std.output[0], priv->buf->std.output[1],
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priv->buf->std.output[2], priv->buf->std.output[3]);
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kfree(output.pointer);
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return 0;
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}
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static int dell_smbios_wmi_call(struct calling_interface_buffer *buffer)
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{
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struct wmi_smbios_priv *priv;
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size_t difference;
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size_t size;
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int ret;
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mutex_lock(&call_mutex);
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priv = get_first_smbios_priv();
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if (!priv) {
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ret = -ENODEV;
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goto out_wmi_call;
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}
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size = sizeof(struct calling_interface_buffer);
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difference = priv->req_buf_size - sizeof(u64) - size;
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memset(&priv->buf->ext, 0, difference);
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memcpy(&priv->buf->std, buffer, size);
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ret = run_smbios_call(priv->wdev);
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memcpy(buffer, &priv->buf->std, size);
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out_wmi_call:
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mutex_unlock(&call_mutex);
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return ret;
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}
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static long dell_smbios_wmi_filter(struct wmi_device *wdev, unsigned int cmd,
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struct wmi_ioctl_buffer *arg)
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{
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struct wmi_smbios_priv *priv;
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int ret = 0;
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switch (cmd) {
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case DELL_WMI_SMBIOS_CMD:
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mutex_lock(&call_mutex);
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priv = dev_get_drvdata(&wdev->dev);
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if (!priv) {
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ret = -ENODEV;
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goto fail_smbios_cmd;
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}
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memcpy(priv->buf, arg, priv->req_buf_size);
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if (dell_smbios_call_filter(&wdev->dev, &priv->buf->std)) {
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dev_err(&wdev->dev, "Invalid call %d/%d:%8x\n",
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priv->buf->std.cmd_class,
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priv->buf->std.cmd_select,
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priv->buf->std.input[0]);
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ret = -EFAULT;
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goto fail_smbios_cmd;
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}
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ret = run_smbios_call(priv->wdev);
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if (ret)
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goto fail_smbios_cmd;
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memcpy(arg, priv->buf, priv->req_buf_size);
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fail_smbios_cmd:
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mutex_unlock(&call_mutex);
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break;
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default:
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ret = -ENOIOCTLCMD;
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}
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return ret;
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}
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static int dell_smbios_wmi_probe(struct wmi_device *wdev)
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{
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struct wmi_driver *wdriver =
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container_of(wdev->dev.driver, struct wmi_driver, driver);
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struct wmi_smbios_priv *priv;
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u32 hotfix;
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int count;
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int ret;
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ret = dell_wmi_get_descriptor_valid();
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if (ret)
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return ret;
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priv = devm_kzalloc(&wdev->dev, sizeof(struct wmi_smbios_priv),
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GFP_KERNEL);
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if (!priv)
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return -ENOMEM;
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/* WMI buffer size will be either 4k or 32k depending on machine */
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if (!dell_wmi_get_size(&priv->req_buf_size))
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return -EPROBE_DEFER;
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/* some SMBIOS calls fail unless BIOS contains hotfix */
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if (!dell_wmi_get_hotfix(&hotfix))
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return -EPROBE_DEFER;
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if (!hotfix) {
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dev_warn(&wdev->dev,
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"WMI SMBIOS userspace interface not supported(%u), try upgrading to a newer BIOS\n",
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hotfix);
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wdriver->filter_callback = NULL;
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}
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/* add in the length object we will use internally with ioctl */
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priv->req_buf_size += sizeof(u64);
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ret = set_required_buffer_size(wdev, priv->req_buf_size);
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if (ret)
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return ret;
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count = get_order(priv->req_buf_size);
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priv->buf = (void *)__get_free_pages(GFP_KERNEL, count);
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if (!priv->buf)
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return -ENOMEM;
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/* ID is used by dell-smbios to set priority of drivers */
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wdev->dev.id = 1;
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ret = dell_smbios_register_device(&wdev->dev, &dell_smbios_wmi_call);
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if (ret)
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goto fail_register;
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priv->wdev = wdev;
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dev_set_drvdata(&wdev->dev, priv);
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mutex_lock(&list_mutex);
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list_add_tail(&priv->list, &wmi_list);
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mutex_unlock(&list_mutex);
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return 0;
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fail_register:
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free_pages((unsigned long)priv->buf, count);
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return ret;
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}
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static int dell_smbios_wmi_remove(struct wmi_device *wdev)
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{
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struct wmi_smbios_priv *priv = dev_get_drvdata(&wdev->dev);
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int count;
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mutex_lock(&call_mutex);
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mutex_lock(&list_mutex);
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list_del(&priv->list);
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mutex_unlock(&list_mutex);
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dell_smbios_unregister_device(&wdev->dev);
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count = get_order(priv->req_buf_size);
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free_pages((unsigned long)priv->buf, count);
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mutex_unlock(&call_mutex);
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return 0;
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}
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static const struct wmi_device_id dell_smbios_wmi_id_table[] = {
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{ .guid_string = DELL_WMI_SMBIOS_GUID },
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{ },
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};
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static void parse_b1_table(const struct dmi_header *dm)
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{
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struct misc_bios_flags_structure *flags =
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container_of(dm, struct misc_bios_flags_structure, header);
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/* 4 bytes header, 8 bytes flags */
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if (dm->length < 12)
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return;
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if (dm->handle != 0xb100)
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return;
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if ((flags->flags0 & FLAG_HAS_ACPI_WMI))
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wmi_supported = 1;
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}
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static void find_b1(const struct dmi_header *dm, void *dummy)
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{
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switch (dm->type) {
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case 0xb1: /* misc bios flags */
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parse_b1_table(dm);
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break;
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}
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}
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static struct wmi_driver dell_smbios_wmi_driver = {
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.driver = {
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.name = "dell-smbios",
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},
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.probe = dell_smbios_wmi_probe,
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.remove = dell_smbios_wmi_remove,
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.id_table = dell_smbios_wmi_id_table,
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.filter_callback = dell_smbios_wmi_filter,
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};
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int init_dell_smbios_wmi(void)
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{
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dmi_walk(find_b1, NULL);
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if (!wmi_supported)
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return -ENODEV;
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return wmi_driver_register(&dell_smbios_wmi_driver);
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}
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void exit_dell_smbios_wmi(void)
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{
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wmi_driver_unregister(&dell_smbios_wmi_driver);
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}
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MODULE_ALIAS("wmi:" DELL_WMI_SMBIOS_GUID);
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