[PATCH 5/6] rust: drm: Pass registration data to ioctl handlers

From: Danilo Krummrich

Date: Wed May 06 2026 - 18:13:39 EST


Pass &<Self::RegistrationData as ForLt>::Of<'_> after the device
argument to ioctl handlers. The lifetime is shortened from 'static via
ForLt::cast_ref; the reference is valid for the duration of the
drm_dev_enter/exit critical section held by UnbindGuard.

Signed-off-by: Danilo Krummrich <dakr@xxxxxxxxxx>
---
drivers/gpu/drm/nova/file.rs | 3 +++
drivers/gpu/drm/tyr/file.rs | 1 +
rust/kernel/drm/ioctl.rs | 5 +++--
3 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/nova/file.rs b/drivers/gpu/drm/nova/file.rs
index a3b7bd36792c..4c9fa409a8be 100644
--- a/drivers/gpu/drm/nova/file.rs
+++ b/drivers/gpu/drm/nova/file.rs
@@ -24,6 +24,7 @@ impl File {
/// IOCTL: get_param: Query GPU / driver metadata.
pub(crate) fn get_param(
dev: &NovaDevice,
+ _reg_data: &(),
getparam: &mut uapi::drm_nova_getparam,
_file: &drm::File<File>,
) -> Result<u32> {
@@ -44,6 +45,7 @@ pub(crate) fn get_param(
/// IOCTL: gem_create: Create a new DRM GEM object.
pub(crate) fn gem_create(
dev: &NovaDevice,
+ _reg_data: &(),
req: &mut uapi::drm_nova_gem_create,
file: &drm::File<File>,
) -> Result<u32> {
@@ -57,6 +59,7 @@ pub(crate) fn gem_create(
/// IOCTL: gem_info: Query GEM metadata.
pub(crate) fn gem_info(
_dev: &NovaDevice,
+ _reg_data: &(),
req: &mut uapi::drm_nova_gem_info,
file: &drm::File<File>,
) -> Result<u32> {
diff --git a/drivers/gpu/drm/tyr/file.rs b/drivers/gpu/drm/tyr/file.rs
index 31411da203c5..6262114c6a8d 100644
--- a/drivers/gpu/drm/tyr/file.rs
+++ b/drivers/gpu/drm/tyr/file.rs
@@ -29,6 +29,7 @@ fn open(_dev: &drm::Device<Self::Driver>) -> Result<Pin<KBox<Self>>> {
impl TyrDrmFileData {
pub(crate) fn dev_query(
ddev: &TyrDrmDevice,
+ _reg_data: &(),
devquery: &mut uapi::drm_panthor_dev_query,
_file: &TyrDrmFile,
) -> Result<u32> {
diff --git a/rust/kernel/drm/ioctl.rs b/rust/kernel/drm/ioctl.rs
index aa72b44f645d..dd177bc399b2 100644
--- a/rust/kernel/drm/ioctl.rs
+++ b/rust/kernel/drm/ioctl.rs
@@ -83,6 +83,7 @@ pub mod internal {
///
/// ```ignore
/// fn foo(device: &kernel::drm::Device<Self>,
+/// reg_data: &<Self::RegistrationData as kernel::types::ForLt>::Of<'_>,
/// data: &mut uapi::argument_type,
/// file: &kernel::drm::File<Self::File>,
/// ) -> Result<u32>
@@ -140,7 +141,7 @@ macro_rules! declare_drm_ioctls {
let dev = unsafe {
$crate::drm::device::Device::from_raw(raw_dev)
};
- let _guard = match $crate::drm::device::unbind_guard(dev) {
+ let guard = match $crate::drm::device::unbind_guard(dev) {
Some(g) => g,
None => return $crate::error::code::ENODEV.to_errno(),
};
@@ -156,7 +157,7 @@ macro_rules! declare_drm_ioctls {
// SAFETY: This is just the DRM file structure
let file = unsafe { $crate::drm::File::from_raw(raw_file) };

- match $func(dev, data, file) {
+ match $func(dev, guard.registration_data(), data, file) {
Err(e) => e.to_errno(),
Ok(i) => i.try_into()
.unwrap_or($crate::error::code::ERANGE.to_errno()),
--
2.54.0