firmware: dmi: Add dmi_memdev_handle

Add a utility function dmi_memdev_handle() which returns the DMI
handle associated with a given memory slot. This will allow kernel
drivers to iterate over the memory slots.

Signed-off-by: Jean Delvare <jdelvare@suse.de>
diff --git a/drivers/firmware/dmi_scan.c b/drivers/firmware/dmi_scan.c
index 6f28e51..2045566 100644
--- a/drivers/firmware/dmi_scan.c
+++ b/drivers/firmware/dmi_scan.c
@@ -1151,3 +1151,19 @@ u8 dmi_memdev_type(u16 handle)
 	return 0x0;	/* Not a valid value */
 }
 EXPORT_SYMBOL_GPL(dmi_memdev_type);
+
+/**
+ *	dmi_memdev_handle - get the DMI handle of a memory slot
+ *	@slot: slot number
+ *
+ *	Return the DMI handle associated with a given memory slot, or %0xFFFF
+ *      if there is no such slot.
+ */
+u16 dmi_memdev_handle(int slot)
+{
+	if (dmi_memdev && slot >= 0 && slot < dmi_memdev_nr)
+		return dmi_memdev[slot].handle;
+
+	return 0xffff;	/* Not a valid value */
+}
+EXPORT_SYMBOL_GPL(dmi_memdev_handle);