new file mode 100644
@@ -0,0 +1,41 @@
+What: /dev/wmi/dell-smbios
+Date: November 2017
+KernelVersion: 4.15
+Contact: "Mario Limonciello" <mario.limonciello@dell.com>
+Description:
+ Perform SMBIOS calls on supported Dell machines.
+ through the Dell ACPI-WMI interface.
+
+ IOCTL's and buffer formats are defined in:
+ <uapi/linux/wmi.h>
+
+ 1) To perform an SMBIOS call from userspace, you'll need to
+ first determine the minimum size of the calling interface
+ buffer for your machine.
+ Platforms that contain larger buffers can return larger
+ objects from the system firmware.
+ Commonly this size is either 4k or 32k.
+
+ To determine the size of the buffer read() a u64 dword from
+ the WMI character device /dev/wmi/dell-smbios.
+
+ 2) After you've determined the minimum size of the calling
+ interface buffer, you can allocate a structure that represents
+ the structure documented above.
+
+ 3) In the 'length' object store the size of the buffer you
+ determined above and allocated.
+
+ 4) In this buffer object, prepare as necessary for the SMBIOS
+ call you're interested in. Typically SMBIOS buffers have
+ "class", "select", and "input" defined to values that coincide
+ with the data you are interested in.
+ Documenting class/select/input values is outside of the scope
+ of this documentation. Check with the libsmbios project for
+ further documentation on these values.
+
+ 6) Run the call by using ioctl() as described in the header.
+
+ 7) The output will be returned in the buffer object.
+
+ 8) Be sure to free up your allocated object.
@@ -30,17 +30,6 @@ struct misc_bios_flags_structure {
#define DELL_WMI_SMBIOS_GUID "A80593CE-A997-11DA-B012-B622A1EF5492"
-struct dell_wmi_extensions {
- __u32 argattrib;
- __u32 blength;
- __u8 data[];
-} __packed;
-
-struct dell_wmi_smbios_buffer {
- struct calling_interface_buffer std;
- struct dell_wmi_extensions ext;
-} __packed;
-
struct wmi_smbios_priv {
struct dell_wmi_smbios_buffer *buf;
struct list_head list;
@@ -117,6 +106,42 @@ int dell_smbios_wmi_call(struct calling_interface_buffer *buffer)
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_smbios_priv *priv;
@@ -135,6 +160,12 @@ static int dell_smbios_wmi_probe(struct wmi_device *wdev)
if (!dell_wmi_get_size(&priv->req_buf_size))
return -EPROBE_DEFER;
+ /* 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)
@@ -210,6 +241,7 @@ static struct wmi_driver dell_smbios_wmi_driver = {
.probe = dell_smbios_wmi_probe,
.remove = dell_smbios_wmi_remove,
.id_table = dell_smbios_wmi_id_table,
+ .filter_callback = dell_smbios_wmi_filter,
};
static int __init init_dell_smbios_wmi(void)
@@ -17,23 +17,11 @@
#define _DELL_SMBIOS_H_
#include <linux/device.h>
+#include <uapi/linux/wmi.h>
-/* Classes and selects used in kernel drivers */
-#define CLASS_TOKEN_READ 0
-#define CLASS_TOKEN_WRITE 1
-#define SELECT_TOKEN_STD 0
-#define SELECT_TOKEN_BAT 1
-#define SELECT_TOKEN_AC 2
+/* Classes and selects used only in kernel drivers */
#define CLASS_KBD_BACKLIGHT 4
#define SELECT_KBD_BACKLIGHT 11
-#define CLASS_FLASH_INTERFACE 7
-#define SELECT_FLASH_INTERFACE 3
-#define CLASS_ADMIN_PROP 10
-#define SELECT_ADMIN_PROP 3
-#define CLASS_INFO 17
-#define SELECT_RFKILL 11
-#define SELECT_APP_REGISTRATION 3
-#define SELECT_DOCK 22
/* Tokens used in kernel drivers, any of these
* should be filtered from userspace access
@@ -50,24 +38,8 @@
#define GLOBAL_MIC_MUTE_ENABLE 0x0364
#define GLOBAL_MIC_MUTE_DISABLE 0x0365
-/* tokens whitelisted to userspace use */
-#define CAPSULE_EN_TOKEN 0x0461
-#define CAPSULE_DIS_TOKEN 0x0462
-#define WSMT_EN_TOKEN 0x04EC
-#define WSMT_DIS_TOKEN 0x04ED
-
struct notifier_block;
-/* This structure will be modified by the firmware when we enter
- * system management mode, hence the volatiles */
-
-struct calling_interface_buffer {
- u16 cmd_class;
- u16 cmd_select;
- volatile u32 input[4];
- volatile u32 output[4];
-} __packed;
-
struct calling_interface_token {
u16 tokenID;
u16 location;
@@ -10,6 +10,7 @@
#ifndef _UAPI_LINUX_WMI_H
#define _UAPI_LINUX_WMI_H
+#include <linux/ioctl.h>
#include <linux/types.h>
/* WMI bus will filter all WMI vendor driver requests through this IOC */
@@ -23,4 +24,50 @@ struct wmi_ioctl_buffer {
__u8 data[];
};
+/* This structure may be modified by the firmware when we enter
+ * system management mode through SMM, hence the volatiles
+ */
+struct calling_interface_buffer {
+ __u16 cmd_class;
+ __u16 cmd_select;
+ volatile __u32 input[4];
+ volatile __u32 output[4];
+} __packed;
+
+struct dell_wmi_extensions {
+ __u32 argattrib;
+ __u32 blength;
+ __u8 data[];
+} __packed;
+
+struct dell_wmi_smbios_buffer {
+ __u64 length;
+ struct calling_interface_buffer std;
+ struct dell_wmi_extensions ext;
+} __packed;
+
+/* Whitelisted smbios class/select commands */
+#define CLASS_TOKEN_READ 0
+#define CLASS_TOKEN_WRITE 1
+#define SELECT_TOKEN_STD 0
+#define SELECT_TOKEN_BAT 1
+#define SELECT_TOKEN_AC 2
+#define CLASS_FLASH_INTERFACE 7
+#define SELECT_FLASH_INTERFACE 3
+#define CLASS_ADMIN_PROP 10
+#define SELECT_ADMIN_PROP 3
+#define CLASS_INFO 17
+#define SELECT_RFKILL 11
+#define SELECT_APP_REGISTRATION 3
+#define SELECT_DOCK 22
+
+/* whitelisted tokens */
+#define CAPSULE_EN_TOKEN 0x0461
+#define CAPSULE_DIS_TOKEN 0x0462
+#define WSMT_EN_TOKEN 0x04EC
+#define WSMT_DIS_TOKEN 0x04ED
+
+/* Dell SMBIOS calling IOCTL command used by dell-smbios-wmi */
+#define DELL_WMI_SMBIOS_CMD _IOWR(WMI_IOC, 0, struct dell_wmi_smbios_buffer)
+
#endif