iommu: Enable debugfs exposure of IOMMU driver internals
Provide base enablement for using debugfs to expose internal data of an
IOMMU driver. When called, create the /sys/kernel/debug/iommu directory.
Emit a strong warning at boot time to indicate that this feature is
enabled.
This function is called from iommu_init, and creates the initial DebugFS
directory. Drivers may then call iommu_debugfs_new_driver_dir() to
instantiate a device-specific directory to expose internal data.
It will return a pointer to the new dentry structure created in
/sys/kernel/debug/iommu, or NULL in the event of a failure.
Since the IOMMU driver can not be removed from the running system, there
is no need for an "off" function.
Signed-off-by: Gary R Hook <gary.hook@amd.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig
index e055d22..ab9181d 100644
--- a/drivers/iommu/Kconfig
+++ b/drivers/iommu/Kconfig
@@ -60,6 +60,16 @@
endmenu
+config IOMMU_DEBUGFS
+ bool "Export IOMMU internals in DebugFS"
+ depends on DEBUG_FS
+ help
+ Allows exposure of IOMMU device internals. This option enables
+ the use of debugfs by IOMMU drivers as required. Devices can,
+ at initialization time, cause the IOMMU code to create a top-level
+ debug/iommu directory, and then populate a subdirectory with
+ entries as required.
+
config IOMMU_IOVA
tristate