platform/x86: dell-smbios-wmi: Add new WMI dispatcher driver

The dell-smbios stack only currently uses an SMI interface which grants
direct access to physical memory to the firmware SMM methods via a pointer.

This dispatcher driver adds a WMI-ACPI interface that is detected by WMI
probe and preferred over the SMI interface in dell-smbios.

Changing this to operate over WMI-ACPI will use an ACPI OperationRegion
for a buffer of data storage when SMM calls are performed.

This is a safer approach to use in kernel drivers as the SMM will
only have access to that OperationRegion.

Signed-off-by: Mario Limonciello <mario.limonciello@dell.com>
Reviewed-by: Edward O'Callaghan <quasisec@google.com>
Signed-off-by: Darren Hart (VMware) <dvhart@infradead.org>

1 files changed, 14 insertions, 0 deletions

diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
index ebe7870a7d9f..1157efcc28c7 100644
--- a/drivers/platform/x86/Kconfig
+++ b/drivers/platform/x86/Kconfig
@@ -94,6 +94,20 @@ config ASUS_LAPTOP
 config DELL_SMBIOS
 	tristate
 
+config DELL_SMBIOS_WMI
+	tristate "Dell SMBIOS calling interface (WMI implementation)"
+	depends on ACPI_WMI
+	select DELL_WMI_DESCRIPTOR
+	default ACPI_WMI
+	select DELL_SMBIOS
+	---help---
+	This provides an implementation for the Dell SMBIOS calling interface
+	communicated over ACPI-WMI.
+
+	If you have a Dell computer from >2007 you should say Y or M here.
+	If you aren't sure and this module doesn't work for your computer
+	it just won't load.
+
 config DELL_SMBIOS_SMM
 	tristate "Dell SMBIOS calling interface (SMM implementation)"
 	depends on DCDBAS