This patch series adds the nova-drm skeleton driver.
nova-drm is connected to nova-core through the auxiliary bus and implements the
DRM parts of the nova driver stack.
For now, it implements the fundamental DRM abstractions, i.e. creates a DRM
device and registers it, exposing a three sample IOCTLs.
DRM_IOCTL_NOVA_GETPARAM
- provides the PCI bar size from the bar that maps the GPUs VRAM from
nova-core
DRM_IOCTL_NOVA_GEM_CREATE
- creates a new dummy DRM GEM object and returns a handle
DRM_IOCTL_NOVA_GEM_INFO
- provides metadata for the DRM GEM object behinda given handle
I implemented a small userspace test suite [1] that utilizes this
interface.
This patch series depends on the auxiliary bus abstractions [2] and the DRM
abstractions [3]; the patches from this series are also in [4].
[1] https://gitlab.freedesktop.org/dakr/drm-test
[2]
https://web.git.kernel.org/pub/scm/linux/kernel/git/dakr/linux.git/log/?h=rust/auxiliary
[3] https://gitlab.freedesktop.org/drm/misc/kernel/-/tree/topic/rust-drm
[4] https://gitlab.freedesktop.org/drm/nova/-/tree/staging/nova-drm
Danilo Krummrich (2):
gpu: nova-core: register auxiliary device for nova-drm
drm: nova-drm: add initial driver skeleton
MAINTAINERS | 12 ++++
drivers/gpu/drm/Kconfig | 2 +
drivers/gpu/drm/Makefile | 1 +
drivers/gpu/drm/nova/Kconfig | 14 ++++
drivers/gpu/drm/nova/Makefile | 3 +
drivers/gpu/drm/nova/driver.rs | 70 ++++++++++++++++++++
drivers/gpu/drm/nova/file.rs | 68 +++++++++++++++++++
drivers/gpu/drm/nova/gem.rs | 49 ++++++++++++++
drivers/gpu/drm/nova/nova.rs | 17 +++++
drivers/gpu/nova-core/Kconfig | 1 +
drivers/gpu/nova-core/driver.rs | 9 ++-
drivers/gpu/nova-core/nova_core.rs | 2 +
include/uapi/drm/nova_drm.h | 101 +++++++++++++++++++++++++++++
rust/uapi/uapi_helper.h | 1 +
14 files changed, 349 insertions(+), 1 deletion(-)
create mode 100644 drivers/gpu/drm/nova/Kconfig
create mode 100644 drivers/gpu/drm/nova/Makefile
create mode 100644 drivers/gpu/drm/nova/driver.rs
create mode 100644 drivers/gpu/drm/nova/file.rs
create mode 100644 drivers/gpu/drm/nova/gem.rs
create mode 100644 drivers/gpu/drm/nova/nova.rs
create mode 100644 include/uapi/drm/nova_drm.h
--
2.49.0
Danilo Krummrich
2025-Mar-25 23:21 UTC
[PATCH 1/2] gpu: nova-core: register auxiliary device for nova-drm
Register an auxiliary device for nova-drm.
For now always use zero for the auxiliary device' ID; we don't use it
yet
anyways. However, once it lands, we should switch to XArray.
Signed-off-by: Danilo Krummrich <dakr at kernel.org>
---
drivers/gpu/nova-core/Kconfig | 1 +
drivers/gpu/nova-core/driver.rs | 9 ++++++++-
drivers/gpu/nova-core/nova_core.rs | 2 ++
3 files changed, 11 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/nova-core/Kconfig b/drivers/gpu/nova-core/Kconfig
index ad0c06756516..67f99b6a023a 100644
--- a/drivers/gpu/nova-core/Kconfig
+++ b/drivers/gpu/nova-core/Kconfig
@@ -1,5 +1,6 @@
config NOVA_CORE
tristate "Nova Core GPU driver"
+ depends on AUXILIARY_BUS
depends on PCI
depends on RUST
depends on RUST_FW_LOADER_ABSTRACTIONS
diff --git a/drivers/gpu/nova-core/driver.rs b/drivers/gpu/nova-core/driver.rs
index a08fb6599267..9ed39637d43f 100644
--- a/drivers/gpu/nova-core/driver.rs
+++ b/drivers/gpu/nova-core/driver.rs
@@ -1,6 +1,6 @@
// SPDX-License-Identifier: GPL-2.0
-use kernel::{bindings, c_str, device::Core, pci, prelude::*};
+use kernel::{auxiliary, bindings, c_str, device::Core, pci, prelude::*};
use crate::gpu::Gpu;
@@ -8,6 +8,7 @@
pub(crate) struct NovaCore {
#[pin]
pub(crate) gpu: Gpu,
+ _reg: auxiliary::Registration,
}
const BAR0_SIZE: usize = 8;
@@ -38,6 +39,12 @@ fn probe(pdev: &pci::Device<Core>, _info:
&Self::IdInfo) -> Result<Pin<KBox<Self
let this = KBox::pin_init(
try_pin_init!(Self {
gpu <- Gpu::new(pdev, bar)?,
+ _reg: auxiliary::Registration::new(
+ pdev.as_ref(),
+ c_str!("nova-drm"),
+ 0, // TODO: Once it lands, use XArray, for now we don't
use the ID.
+ crate::MODULE_NAME
+ )?,
}),
GFP_KERNEL,
)?;
diff --git a/drivers/gpu/nova-core/nova_core.rs
b/drivers/gpu/nova-core/nova_core.rs
index a91cd924054b..618632f0abcc 100644
--- a/drivers/gpu/nova-core/nova_core.rs
+++ b/drivers/gpu/nova-core/nova_core.rs
@@ -8,6 +8,8 @@
mod regs;
mod util;
+pub(crate) const MODULE_NAME: &kernel::str::CStr = <LocalModule as
kernel::ModuleMetadata>::NAME;
+
kernel::module_pci_driver! {
type: driver::NovaCore,
name: "NovaCore",
--
2.49.0
Danilo Krummrich
2025-Mar-25 23:21 UTC
[PATCH 2/2] drm: nova-drm: add initial driver skeleton
Add the initial nova-drm driver skeleton.
nova-drm is connected to nova-core through the auxiliary bus and
implements the DRM parts of the nova driver stack.
For now, it implements the fundamental DRM abstractions, i.e. creates a
DRM device and registers it, exposing a three sample IOCTLs.
DRM_IOCTL_NOVA_GETPARAM
- provides the PCI bar size from the bar that maps the GPUs VRAM
from nova-core
DRM_IOCTL_NOVA_GEM_CREATE
- creates a new dummy DRM GEM object and returns a handle
DRM_IOCTL_NOVA_GEM_INFO
- provides metadata for the DRM GEM object behind a given handle
I implemented a small userspace test suite [1] that utilizes this
interface.
Link: https://gitlab.freedesktop.org/dakr/drm-test [1]
Signed-off-by: Danilo Krummrich <dakr at kernel.org>
---
MAINTAINERS | 12 ++++
drivers/gpu/drm/Kconfig | 2 +
drivers/gpu/drm/Makefile | 1 +
drivers/gpu/drm/nova/Kconfig | 14 +++++
drivers/gpu/drm/nova/Makefile | 3 +
drivers/gpu/drm/nova/driver.rs | 70 +++++++++++++++++++++++
drivers/gpu/drm/nova/file.rs | 68 ++++++++++++++++++++++
drivers/gpu/drm/nova/gem.rs | 49 ++++++++++++++++
drivers/gpu/drm/nova/nova.rs | 17 ++++++
include/uapi/drm/nova_drm.h | 101 +++++++++++++++++++++++++++++++++
rust/uapi/uapi_helper.h | 1 +
11 files changed, 338 insertions(+)
create mode 100644 drivers/gpu/drm/nova/Kconfig
create mode 100644 drivers/gpu/drm/nova/Makefile
create mode 100644 drivers/gpu/drm/nova/driver.rs
create mode 100644 drivers/gpu/drm/nova/file.rs
create mode 100644 drivers/gpu/drm/nova/gem.rs
create mode 100644 drivers/gpu/drm/nova/nova.rs
create mode 100644 include/uapi/drm/nova_drm.h
diff --git a/MAINTAINERS b/MAINTAINERS
index c704431f02aa..74e95b8db4d1 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -7465,6 +7465,18 @@ T: git https://gitlab.freedesktop.org/drm/nova.git
nova-next
F: Documentation/gpu/nova/
F: drivers/gpu/nova-core/
+DRM DRIVER FOR NVIDIA GPUS [RUST]
+M: Danilo Krummrich <dakr at kernel.org>
+L: nouveau at lists.freedesktop.org
+S: Supported
+Q: https://patchwork.freedesktop.org/project/nouveau/
+B: https://gitlab.freedesktop.org/drm/nova/-/issues
+C: irc://irc.oftc.net/nouveau
+T: git https://gitlab.freedesktop.org/drm/nova.git nova-next
+F: Documentation/gpu/nova/
+F: drivers/gpu/drm/nova/
+F: include/uapi/drm/nova_drm.h
+
DRM DRIVER FOR OLIMEX LCD-OLINUXINO PANELS
M: Stefan Mavrodiev <stefan at olimex.com>
S: Maintained
diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
index fbef3f471bd0..e6dcc1ebcfd5 100644
--- a/drivers/gpu/drm/Kconfig
+++ b/drivers/gpu/drm/Kconfig
@@ -336,6 +336,8 @@ source "drivers/gpu/drm/amd/amdgpu/Kconfig"
source "drivers/gpu/drm/nouveau/Kconfig"
+source "drivers/gpu/drm/nova/Kconfig"
+
source "drivers/gpu/drm/i915/Kconfig"
source "drivers/gpu/drm/xe/Kconfig"
diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
index 19fb370fbc56..70ddbb37ec56 100644
--- a/drivers/gpu/drm/Makefile
+++ b/drivers/gpu/drm/Makefile
@@ -176,6 +176,7 @@ obj-$(CONFIG_DRM_VMWGFX)+= vmwgfx/
obj-$(CONFIG_DRM_VGEM) += vgem/
obj-$(CONFIG_DRM_VKMS) += vkms/
obj-$(CONFIG_DRM_NOUVEAU) +=nouveau/
+obj-$(CONFIG_DRM_NOVA) += nova/
obj-$(CONFIG_DRM_EXYNOS) +=exynos/
obj-$(CONFIG_DRM_ROCKCHIP) +=rockchip/
obj-$(CONFIG_DRM_GMA500) += gma500/
diff --git a/drivers/gpu/drm/nova/Kconfig b/drivers/gpu/drm/nova/Kconfig
new file mode 100644
index 000000000000..cf6261584c81
--- /dev/null
+++ b/drivers/gpu/drm/nova/Kconfig
@@ -0,0 +1,14 @@
+config DRM_NOVA
+ tristate "Nova DRM driver"
+ depends on AUXILIARY_BUS
+ depends on DRM
+ depends on PCI
+ depends on RUST
+ default n
+ help
+ Choose this if you want to build the Nova DRM driver for Nvidia
+ GSP-based GPUs.
+
+ This driver is work in progress and may not be functional.
+
+ If M is selected, the module will be called nova.
diff --git a/drivers/gpu/drm/nova/Makefile b/drivers/gpu/drm/nova/Makefile
new file mode 100644
index 000000000000..42019bff3173
--- /dev/null
+++ b/drivers/gpu/drm/nova/Makefile
@@ -0,0 +1,3 @@
+# SPDX-License-Identifier: GPL-2.0
+
+obj-$(CONFIG_DRM_NOVA) += nova.o
diff --git a/drivers/gpu/drm/nova/driver.rs b/drivers/gpu/drm/nova/driver.rs
new file mode 100644
index 000000000000..870a551272c1
--- /dev/null
+++ b/drivers/gpu/drm/nova/driver.rs
@@ -0,0 +1,70 @@
+// SPDX-License-Identifier: GPL-2.0
+
+use kernel::{auxiliary, c_str, device::Core, drm, drm::gem, drm::ioctl,
prelude::*, types::ARef};
+
+use crate::file::File;
+use crate::gem::NovaObject;
+
+pub(crate) struct NovaDriver {
+ #[expect(unused)]
+ drm: ARef<drm::Device<Self>>,
+}
+
+/// Convienence type alias for the DRM device type for this driver
+pub(crate) type NovaDevice = drm::Device<NovaDriver>;
+
+#[pin_data]
+pub(crate) struct NovaData {
+ pub(crate) adev: ARef<auxiliary::Device>,
+}
+
+const INFO: drm::DriverInfo = drm::DriverInfo {
+ major: 0,
+ minor: 0,
+ patchlevel: 0,
+ name: c_str!("nova"),
+ desc: c_str!("Nvidia Graphics"),
+ date: c_str!("20240227"),
+};
+
+const NOVA_CORE_MODULE_NAME: &CStr = c_str!("NovaCore");
+const AUXILIARY_NAME: &CStr = c_str!("nova-drm");
+
+kernel::auxiliary_device_table!(
+ AUX_TABLE,
+ MODULE_AUX_TABLE,
+ <NovaDriver as auxiliary::Driver>::IdInfo,
+ [(
+ auxiliary::DeviceId::new(NOVA_CORE_MODULE_NAME, AUXILIARY_NAME),
+ ()
+ )]
+);
+
+impl auxiliary::Driver for NovaDriver {
+ type IdInfo = ();
+ const ID_TABLE: auxiliary::IdTable<Self::IdInfo> = &AUX_TABLE;
+
+ fn probe(adev: &auxiliary::Device<Core>, _info:
&Self::IdInfo) -> Result<Pin<KBox<Self>>> {
+ let data = try_pin_init!(NovaData { adev: adev.into() });
+
+ let drm = drm::Device::<Self>::new(adev.as_ref(), data)?;
+ drm::Registration::new_foreign_owned(drm.clone(), 0)?;
+
+ Ok(KBox::new(Self { drm }, GFP_KERNEL)?.into())
+ }
+}
+
+#[vtable]
+impl drm::Driver for NovaDriver {
+ type Data = NovaData;
+ type File = File;
+ type Object = gem::Object<NovaObject>;
+
+ const INFO: drm::DriverInfo = INFO;
+
+ kernel::declare_drm_ioctls! {
+ (NOVA_GETPARAM, drm_nova_getparam, ioctl::RENDER_ALLOW,
File::get_param),
+ (NOVA_GEM_CREATE, drm_nova_gem_create, ioctl::AUTH |
ioctl::RENDER_ALLOW, File::gem_create),
+ (NOVA_GEM_INFO, drm_nova_gem_info, ioctl::AUTH | ioctl::RENDER_ALLOW,
File::gem_info),
+ }
+}
diff --git a/drivers/gpu/drm/nova/file.rs b/drivers/gpu/drm/nova/file.rs
new file mode 100644
index 000000000000..a2ae185f0b4c
--- /dev/null
+++ b/drivers/gpu/drm/nova/file.rs
@@ -0,0 +1,68 @@
+// SPDX-License-Identifier: GPL-2.0
+
+use crate::driver::{NovaDevice, NovaDriver};
+use crate::gem::NovaObject;
+use kernel::{
+ alloc::flags::*,
+ drm::{self, gem::BaseObject},
+ pci,
+ prelude::*,
+ uapi,
+};
+
+pub(crate) struct File;
+
+impl drm::file::DriverFile for File {
+ type Driver = NovaDriver;
+
+ fn open(_dev: &NovaDevice) ->
Result<Pin<KBox<Self>>> {
+ Ok(KBox::new(Self, GFP_KERNEL)?.into())
+ }
+}
+
+impl File {
+ /// IOCTL: get_param: Query GPU / driver metadata.
+ pub(crate) fn get_param(
+ dev: &NovaDevice,
+ getparam: &mut uapi::drm_nova_getparam,
+ _file: &drm::File<File>,
+ ) -> Result<u32> {
+ let adev = &dev.adev;
+ let parent = adev.parent().ok_or(ENOENT)?;
+ let pdev: &pci::Device = parent.try_into()?;
+
+ getparam.value = match getparam.param as u32 {
+ uapi::NOVA_GETPARAM_VRAM_BAR_SIZE => pdev.resource_len(1)?,
+ _ => return Err(EINVAL),
+ };
+
+ Ok(0)
+ }
+
+ /// IOCTL: gem_create: Create a new DRM GEM object.
+ pub(crate) fn gem_create(
+ dev: &NovaDevice,
+ req: &mut uapi::drm_nova_gem_create,
+ file: &drm::File<File>,
+ ) -> Result<u32> {
+ let obj = NovaObject::new(dev, req.size.try_into()?)?;
+
+ let handle = obj.create_handle(file)?;
+ req.handle = handle;
+
+ Ok(0)
+ }
+
+ /// IOCTL: gem_info: Query GEM metadata.
+ pub(crate) fn gem_info(
+ _dev: &NovaDevice,
+ req: &mut uapi::drm_nova_gem_info,
+ file: &drm::File<File>,
+ ) -> Result<u32> {
+ let bo = NovaObject::lookup_handle(file, req.handle)?;
+
+ req.size = bo.size().try_into()?;
+
+ Ok(0)
+ }
+}
diff --git a/drivers/gpu/drm/nova/gem.rs b/drivers/gpu/drm/nova/gem.rs
new file mode 100644
index 000000000000..33b62d21400c
--- /dev/null
+++ b/drivers/gpu/drm/nova/gem.rs
@@ -0,0 +1,49 @@
+// SPDX-License-Identifier: GPL-2.0
+
+use kernel::{
+ drm,
+ drm::{gem, gem::BaseObject},
+ prelude::*,
+ types::ARef,
+};
+
+use crate::{
+ driver::{NovaDevice, NovaDriver},
+ file::File,
+};
+
+/// GEM Object inner driver data
+#[pin_data]
+pub(crate) struct NovaObject {}
+
+impl gem::BaseDriverObject<gem::Object<NovaObject>> for NovaObject
{
+ fn new(_dev: &NovaDevice, _size: usize) -> impl PinInit<Self,
Error> {
+ try_pin_init!(NovaObject {})
+ }
+}
+
+impl gem::DriverObject for NovaObject {
+ type Driver = NovaDriver;
+}
+
+impl NovaObject {
+ /// Create a new DRM GEM object.
+ pub(crate) fn new(dev: &NovaDevice, size: usize) ->
Result<ARef<gem::Object<Self>>> {
+ let aligned_size = size.next_multiple_of(1 << 12);
+
+ if size == 0 || size > aligned_size {
+ return Err(EINVAL);
+ }
+
+ gem::Object::new(dev, aligned_size)
+ }
+
+ /// Look up a GEM object handle for a `File` and return an `ObjectRef` for
it.
+ #[inline]
+ pub(crate) fn lookup_handle(
+ file: &drm::File<File>,
+ handle: u32,
+ ) -> Result<ARef<gem::Object<Self>>> {
+ gem::Object::lookup_handle(file, handle)
+ }
+}
diff --git a/drivers/gpu/drm/nova/nova.rs b/drivers/gpu/drm/nova/nova.rs
new file mode 100644
index 000000000000..730598defe04
--- /dev/null
+++ b/drivers/gpu/drm/nova/nova.rs
@@ -0,0 +1,17 @@
+// SPDX-License-Identifier: GPL-2.0
+
+//! Nova DRM Driver
+
+mod driver;
+mod file;
+mod gem;
+
+use crate::driver::NovaDriver;
+
+kernel::module_auxiliary_driver! {
+ type: NovaDriver,
+ name: "Nova",
+ author: "Danilo Krummrich",
+ description: "Nova GPU driver",
+ license: "GPL v2",
+}
diff --git a/include/uapi/drm/nova_drm.h b/include/uapi/drm/nova_drm.h
new file mode 100644
index 000000000000..3ca90ed9d2bb
--- /dev/null
+++ b/include/uapi/drm/nova_drm.h
@@ -0,0 +1,101 @@
+/* SPDX-License-Identifier: MIT */
+
+#ifndef __NOVA_DRM_H__
+#define __NOVA_DRM_H__
+
+#include "drm.h"
+
+/* DISCLAIMER: Do not use, this is not a stable uAPI.
+ *
+ * This uAPI serves only testing purposes as long as this driver is still in
+ * development. It is required to implement and test infrastructure which is
+ * upstreamed in the context of this driver. See also [1].
+ *
+ * [1] https://lore.kernel.org/dri-devel/Zfsj0_tb-0-tNrJy at cassiopeiae/T/#u
+ */
+
+#if defined(__cplusplus)
+extern "C" {
+#endif
+
+/*
+ * NOVA_GETPARAM_VRAM_BAR_SIZE
+ *
+ * Query the VRAM BAR size in bytes.
+ */
+#define NOVA_GETPARAM_VRAM_BAR_SIZE 0x1
+
+/**
+ * struct drm_nova_getparam - query GPU and driver metadata
+ */
+struct drm_nova_getparam {
+ /**
+ * @param: The identifier of the parameter to query.
+ */
+ __u64 param;
+
+ /**
+ * @value: The value for the specified parameter.
+ */
+ __u64 value;
+};
+
+/**
+ * struct drm_nova_gem_create - create a new DRM GEM object
+ */
+struct drm_nova_gem_create {
+ /**
+ * @handle: The handle of the new DRM GEM object.
+ */
+ __u32 handle;
+
+ /**
+ * @pad: 32 bit padding, should be 0.
+ */
+ __u32 pad;
+
+ /**
+ * @size: The size of the new DRM GEM object.
+ */
+ __u64 size;
+};
+
+/**
+ * struct drm_nova_gem_info - query DRM GEM object metadata
+ */
+struct drm_nova_gem_info {
+ /**
+ * @handle: The handle of the DRM GEM object to query.
+ */
+ __u32 handle;
+
+ /**
+ * @pad: 32 bit padding, should be 0.
+ */
+ __u32 pad;
+
+ /**
+ * @size: The size of the DRM GEM obejct.
+ */
+ __u64 size;
+};
+
+#define DRM_NOVA_GETPARAM 0x00
+#define DRM_NOVA_GEM_CREATE 0x01
+#define DRM_NOVA_GEM_INFO 0x02
+
+/* Note: this is an enum so that it can be resolved by Rust bindgen. */
+enum {
+ DRM_IOCTL_NOVA_GETPARAM = DRM_IOWR(DRM_COMMAND_BASE + DRM_NOVA_GETPARAM,
+ struct drm_nova_getparam),
+ DRM_IOCTL_NOVA_GEM_CREATE = DRM_IOWR(DRM_COMMAND_BASE + DRM_NOVA_GEM_CREATE,
+ struct drm_nova_gem_create),
+ DRM_IOCTL_NOVA_GEM_INFO = DRM_IOWR(DRM_COMMAND_BASE + DRM_NOVA_GEM_INFO,
+ struct drm_nova_gem_info),
+};
+
+#if defined(__cplusplus)
+}
+#endif
+
+#endif /* __NOVA_DRM_H__ */
diff --git a/rust/uapi/uapi_helper.h b/rust/uapi/uapi_helper.h
index 19587e55e604..1409441359f5 100644
--- a/rust/uapi/uapi_helper.h
+++ b/rust/uapi/uapi_helper.h
@@ -8,6 +8,7 @@
#include <uapi/asm-generic/ioctl.h>
#include <uapi/drm/drm.h>
+#include <uapi/drm/nova_drm.h>
#include <uapi/linux/mdio.h>
#include <uapi/linux/mii.h>
#include <uapi/linux/ethtool.h>
--
2.49.0