1 files changed, 282 insertions, 0 deletions
diff --git a/drivers/platform/x86/dell-smbios-wmi.c b/drivers/platform/x86/dell-smbios-wmi.c
new file mode 100644
index 000000000..0ebcf412f
--- /dev/null
+++ b/drivers/platform/x86/dell-smbios-wmi.c
@@ -0,0 +1,282 @@
+/*
+ *  WMI methods for use with dell-smbios
+ *
+ *  Copyright (c) 2017 Dell Inc.
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License version 2 as
+ *  published by the Free Software Foundation.
+ */
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/dmi.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/uaccess.h>
+#include <linux/wmi.h>
+#include "dell-smbios.h"
+#include "dell-wmi-descriptor.h"
+
+static DEFINE_MUTEX(call_mutex);
+static DEFINE_MUTEX(list_mutex);
+static int wmi_supported;
+
+struct misc_bios_flags_structure {
+	struct dmi_header header;
+	u16 flags0;
+} __packed;
+#define FLAG_HAS_ACPI_WMI 0x02
+
+#define DELL_WMI_SMBIOS_GUID "A80593CE-A997-11DA-B012-B622A1EF5492"
+
+struct wmi_smbios_priv {
+	struct dell_wmi_smbios_buffer *buf;
+	struct list_head list;
+	struct wmi_device *wdev;
+	struct device *child;
+	u32 req_buf_size;
+};
+static LIST_HEAD(wmi_list);
+
+static inline struct wmi_smbios_priv *get_first_smbios_priv(void)
+{
+	return list_first_entry_or_null(&wmi_list,
+					struct wmi_smbios_priv,
+					list);
+}
+
+static int run_smbios_call(struct wmi_device *wdev)
+{
+	struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL};
+	struct wmi_smbios_priv *priv;
+	struct acpi_buffer input;
+	union acpi_object *obj;
+	acpi_status status;
+
+	priv = dev_get_drvdata(&wdev->dev);
+	input.length = priv->req_buf_size - sizeof(u64);
+	input.pointer = &priv->buf->std;
+
+	dev_dbg(&wdev->dev, "evaluating: %u/%u [%x,%x,%x,%x]\n",
+		priv->buf->std.cmd_class, priv->buf->std.cmd_select,
+		priv->buf->std.input[0], priv->buf->std.input[1],
+		priv->buf->std.input[2], priv->buf->std.input[3]);
+
+	status = wmidev_evaluate_method(wdev, 0, 1, &input, &output);
+	if (ACPI_FAILURE(status))
+		return -EIO;
+	obj = (union acpi_object *)output.pointer;
+	if (obj->type != ACPI_TYPE_BUFFER) {
+		dev_dbg(&wdev->dev, "received type: %d\n", obj->type);
+		if (obj->type == ACPI_TYPE_INTEGER)
+			dev_dbg(&wdev->dev, "SMBIOS call failed: %llu\n",
+				obj->integer.value);
+		kfree(output.pointer);
+		return -EIO;
+	}
+	memcpy(&priv->buf->std, obj->buffer.pointer, obj->buffer.length);
+	dev_dbg(&wdev->dev, "result: [%08x,%08x,%08x,%08x]\n",
+		priv->buf->std.output[0], priv->buf->std.output[1],
+		priv->buf->std.output[2], priv->buf->std.output[3]);
+	kfree(output.pointer);
+
+	return 0;
+}
+
+static int dell_smbios_wmi_call(struct calling_interface_buffer *buffer)
+{
+	struct wmi_smbios_priv *priv;
+	size_t difference;
+	size_t size;
+	int ret;
+
+	mutex_lock(&call_mutex);
+	priv = get_first_smbios_priv();
+	if (!priv) {
+		ret = -ENODEV;
+		goto out_wmi_call;
+	}
+
+	size = sizeof(struct calling_interface_buffer);
+	difference = priv->req_buf_size - sizeof(u64) - size;
+
+	memset(&priv->buf->ext, 0, difference);
+	memcpy(&priv->buf->std, buffer, size);
+	ret = run_smbios_call(priv->wdev);
+	memcpy(buffer, &priv->buf->std, size);
+out_wmi_call:
+	mutex_unlock(&call_mutex);
+
+	return ret;
+}
+
+static long dell_smbios_wmi_filter(struct wmi_device *wdev, unsigned int cmd,
+				   struct wmi_ioctl_buffer *arg)
+{
+	struct wmi_smbios_priv *priv;
+	int ret = 0;
+
+	switch (cmd) {
+	case DELL_WMI_SMBIOS_CMD:
+		mutex_lock(&call_mutex);
+		priv = dev_get_drvdata(&wdev->dev);
+		if (!priv) {
+			ret = -ENODEV;
+			goto fail_smbios_cmd;
+		}
+		memcpy(priv->buf, arg, priv->req_buf_size);
+		if (dell_smbios_call_filter(&wdev->dev, &priv->buf->std)) {
+			dev_err(&wdev->dev, "Invalid call %d/%d:%8x\n",
+				priv->buf->std.cmd_class,
+				priv->buf->std.cmd_select,
+				priv->buf->std.input[0]);
+			ret = -EFAULT;
+			goto fail_smbios_cmd;
+		}
+		ret = run_smbios_call(priv->wdev);
+		if (ret)
+			goto fail_smbios_cmd;
+		memcpy(arg, priv->buf, priv->req_buf_size);
+fail_smbios_cmd:
+		mutex_unlock(&call_mutex);
+		break;
+	default:
+		ret = -ENOIOCTLCMD;
+	}
+	return ret;
+}
+
+static int dell_smbios_wmi_probe(struct wmi_device *wdev)
+{
+	struct wmi_driver *wdriver =
+		container_of(wdev->dev.driver, struct wmi_driver, driver);
+	struct wmi_smbios_priv *priv;
+	u32 hotfix;
+	int count;
+	int ret;
+
+	ret = dell_wmi_get_descriptor_valid();
+	if (ret)
+		return ret;
+
+	priv = devm_kzalloc(&wdev->dev, sizeof(struct wmi_smbios_priv),
+			    GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	/* WMI buffer size will be either 4k or 32k depending on machine */
+	if (!dell_wmi_get_size(&priv->req_buf_size))
+		return -EPROBE_DEFER;
+
+	/* some SMBIOS calls fail unless BIOS contains hotfix */
+	if (!dell_wmi_get_hotfix(&hotfix))
+		return -EPROBE_DEFER;
+	if (!hotfix) {
+		dev_warn(&wdev->dev,
+			"WMI SMBIOS userspace interface not supported(%u), try upgrading to a newer BIOS\n",
+			hotfix);
+		wdriver->filter_callback = NULL;
+	}
+
+	/* add in the length object we will use internally with ioctl */
+	priv->req_buf_size += sizeof(u64);
+	ret = set_required_buffer_size(wdev, priv->req_buf_size);
+	if (ret)
+		return ret;
+
+	count = get_order(priv->req_buf_size);
+	priv->buf = (void *)__get_free_pages(GFP_KERNEL, count);
+	if (!priv->buf)
+		return -ENOMEM;
+
+	/* ID is used by dell-smbios to set priority of drivers */
+	wdev->dev.id = 1;
+	ret = dell_smbios_register_device(&wdev->dev, &dell_smbios_wmi_call);
+	if (ret)
+		goto fail_register;
+
+	priv->wdev = wdev;
+	dev_set_drvdata(&wdev->dev, priv);
+	mutex_lock(&list_mutex);
+	list_add_tail(&priv->list, &wmi_list);
+	mutex_unlock(&list_mutex);
+
+	return 0;
+
+fail_register:
+	free_pages((unsigned long)priv->buf, count);
+	return ret;
+}
+
+static int dell_smbios_wmi_remove(struct wmi_device *wdev)
+{
+	struct wmi_smbios_priv *priv = dev_get_drvdata(&wdev->dev);
+	int count;
+
+	mutex_lock(&call_mutex);
+	mutex_lock(&list_mutex);
+	list_del(&priv->list);
+	mutex_unlock(&list_mutex);
+	dell_smbios_unregister_device(&wdev->dev);
+	count = get_order(priv->req_buf_size);
+	free_pages((unsigned long)priv->buf, count);
+	mutex_unlock(&call_mutex);
+	return 0;
+}
+
+static const struct wmi_device_id dell_smbios_wmi_id_table[] = {
+	{ .guid_string = DELL_WMI_SMBIOS_GUID },
+	{ },
+};
+
+static void parse_b1_table(const struct dmi_header *dm)
+{
+	struct misc_bios_flags_structure *flags =
+	container_of(dm, struct misc_bios_flags_structure, header);
+
+	/* 4 bytes header, 8 bytes flags */
+	if (dm->length < 12)
+		return;
+	if (dm->handle != 0xb100)
+		return;
+	if ((flags->flags0 & FLAG_HAS_ACPI_WMI))
+		wmi_supported = 1;
+}
+
+static void find_b1(const struct dmi_header *dm, void *dummy)
+{
+	switch (dm->type) {
+	case 0xb1: /* misc bios flags */
+		parse_b1_table(dm);
+		break;
+	}
+}
+
+static struct wmi_driver dell_smbios_wmi_driver = {
+	.driver = {
+		.name = "dell-smbios",
+	},
+	.probe = dell_smbios_wmi_probe,
+	.remove = dell_smbios_wmi_remove,
+	.id_table = dell_smbios_wmi_id_table,
+	.filter_callback = dell_smbios_wmi_filter,
+};
+
+int init_dell_smbios_wmi(void)
+{
+	dmi_walk(find_b1, NULL);
+
+	if (!wmi_supported)
+		return -ENODEV;
+
+	return wmi_driver_register(&dell_smbios_wmi_driver);
+}
+
+void exit_dell_smbios_wmi(void)
+{
+	if (wmi_supported)
+		wmi_driver_unregister(&dell_smbios_wmi_driver);
+}
+
+MODULE_ALIAS("wmi:" DELL_WMI_SMBIOS_GUID);