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Danilo Krummrich

2024-Jun-18 23:31 UTC

[PATCH v2 0/8] DRM Rust abstractions and Nova

This patch series implements some basic DRM Rust abstractions and a stub
implementation of the Nova GPU driver.

Nova is intended to be developed upstream, starting out with just a stub driver
to lift some initial required infrastructure upstream. A more detailed
explanation can be found in [1].

This patch series is based on the "Device / Driver and PCI Rust
abstractions"
series [2].

The DRM bits can also be found in [3] and the Nova bits in [4].

Changes in v2:
=============- split up the DRM device / driver abstractions in three separate
commits
- separate `struct drm_device` abstraction in a separte source file more
  cleanly
- switch `struct drm_driver` and `struct file_operations` to 'static
const'
  allocations
- implement `Registration::new_foreign_owned` (using `Devres`), such that we
  don't need to keep the `Registration` alive on the Rust side, but
  automatically revoke it on device unbind
- add missing DRM driver features (Rob)
- use `module_pci_driver!` macro in Nova
- use a const sized `pci::Bar` in Nova
- increase the total amount of Documentation, rephrase some safety comments and
  commit messages for less ambiguity
- fix compilation issues with some documentation example

[1] https://lore.kernel.org/dri-devel/Zfsj0_tb-0-tNrJy at cassiopeiae/T/#u
[2] Reply to this mail titled "Device / Driver and PCI Rust
abstractions".
[3] https://gitlab.freedesktop.org/drm/misc/kernel/-/tree/topic/rust-drm
[4] https://gitlab.freedesktop.org/drm/nova/-/tree/nova-next

Asahi Lina (4):
  rust: drm: ioctl: Add DRM ioctl abstraction
  rust: Add a Sealed trait
  rust: drm: file: Add File abstraction
  rust: drm: gem: Add GEM object abstraction

Danilo Krummrich (4):
  rust: drm: add driver abstractions
  rust: drm: add device abstraction
  rust: drm: add DRM driver registration
  nova: add initial driver stub

 MAINTAINERS                     |  10 +
 drivers/gpu/drm/Kconfig         |   2 +
 drivers/gpu/drm/Makefile        |   1 +
 drivers/gpu/drm/nova/Kconfig    |  12 +
 drivers/gpu/drm/nova/Makefile   |   3 +
 drivers/gpu/drm/nova/driver.rs  |  85 +++++++
 drivers/gpu/drm/nova/file.rs    |  70 ++++++
 drivers/gpu/drm/nova/gem.rs     |  50 ++++
 drivers/gpu/drm/nova/gpu.rs     | 173 ++++++++++++++
 drivers/gpu/drm/nova/nova.rs    |  18 ++
 include/uapi/drm/nova_drm.h     | 101 ++++++++
 rust/bindings/bindings_helper.h |   5 +
 rust/helpers.c                  |  23 ++
 rust/kernel/drm/device.rs       | 182 ++++++++++++++
 rust/kernel/drm/drv.rs          | 199 ++++++++++++++++
 rust/kernel/drm/file.rs         | 116 +++++++++
 rust/kernel/drm/gem/mod.rs      | 409 ++++++++++++++++++++++++++++++++
 rust/kernel/drm/ioctl.rs        | 153 ++++++++++++
 rust/kernel/drm/mod.rs          |   9 +
 rust/kernel/lib.rs              |   7 +
 rust/uapi/uapi_helper.h         |   2 +
 21 files changed, 1630 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/gpu.rs
 create mode 100644 drivers/gpu/drm/nova/nova.rs
 create mode 100644 include/uapi/drm/nova_drm.h
 create mode 100644 rust/kernel/drm/device.rs
 create mode 100644 rust/kernel/drm/drv.rs
 create mode 100644 rust/kernel/drm/file.rs
 create mode 100644 rust/kernel/drm/gem/mod.rs
 create mode 100644 rust/kernel/drm/ioctl.rs
 create mode 100644 rust/kernel/drm/mod.rs


base-commit: 6646240d29b11de3177f71ff777d0ae683c32623
-- 
2.45.1

Danilo Krummrich

2024-Jun-18 23:31 UTC

head link

[PATCH v2 1/8] rust: drm: ioctl: Add DRM ioctl abstraction

From: Asahi Lina <lina at asahilina.net>

DRM drivers need to be able to declare which driver-specific ioctls they
support. Add an abstraction implementing the required types and a helper
macro to generate the ioctl definition inside the DRM driver.

Note that this macro is not usable until further bits of the abstraction
are in place (but it will not fail to compile on its own, if not called).

Signed-off-by: Asahi Lina <lina at asahilina.net>
Signed-off-by: Danilo Krummrich <dakr at redhat.com>
---
 rust/bindings/bindings_helper.h |   1 +
 rust/kernel/drm/ioctl.rs        | 153 ++++++++++++++++++++++++++++++++
 rust/kernel/drm/mod.rs          |   5 ++
 rust/kernel/lib.rs              |   2 +
 rust/uapi/uapi_helper.h         |   1 +
 5 files changed, 162 insertions(+)
 create mode 100644 rust/kernel/drm/ioctl.rs
 create mode 100644 rust/kernel/drm/mod.rs

diff --git a/rust/bindings/bindings_helper.h b/rust/bindings/bindings_helper.h
index 30ad2a0e22d7..ed25b686748e 100644
--- a/rust/bindings/bindings_helper.h
+++ b/rust/bindings/bindings_helper.h
@@ -6,6 +6,7 @@
  * Sorted alphabetically.
  */
 
+#include <drm/drm_ioctl.h>
 #include <kunit/test.h>
 #include <linux/errname.h>
 #include <linux/ethtool.h>
diff --git a/rust/kernel/drm/ioctl.rs b/rust/kernel/drm/ioctl.rs
new file mode 100644
index 000000000000..09ca7a8e7583
--- /dev/null
+++ b/rust/kernel/drm/ioctl.rs
@@ -0,0 +1,153 @@
+// SPDX-License-Identifier: GPL-2.0 OR MIT
+#![allow(non_snake_case)]
+
+//! DRM IOCTL definitions.
+//!
+//! C header:
[`include/linux/drm/drm_ioctl.h`](srctree/include/linux/drm/drm_ioctl.h)
+
+use crate::ioctl;
+
+const BASE: u32 = uapi::DRM_IOCTL_BASE as u32;
+
+/// Construct a DRM ioctl number with no argument.
+#[inline(always)]
+pub const fn IO(nr: u32) -> u32 {
+    ioctl::_IO(BASE, nr)
+}
+
+/// Construct a DRM ioctl number with a read-only argument.
+#[inline(always)]
+pub const fn IOR<T>(nr: u32) -> u32 {
+    ioctl::_IOR::<T>(BASE, nr)
+}
+
+/// Construct a DRM ioctl number with a write-only argument.
+#[inline(always)]
+pub const fn IOW<T>(nr: u32) -> u32 {
+    ioctl::_IOW::<T>(BASE, nr)
+}
+
+/// Construct a DRM ioctl number with a read-write argument.
+#[inline(always)]
+pub const fn IOWR<T>(nr: u32) -> u32 {
+    ioctl::_IOWR::<T>(BASE, nr)
+}
+
+/// Descriptor type for DRM ioctls. Use the `declare_drm_ioctls!{}` macro to
construct them.
+pub type DrmIoctlDescriptor = bindings::drm_ioctl_desc;
+
+/// This is for ioctl which are used for rendering, and require that the file
descriptor is either
+/// for a render node, or if it?s a legacy/primary node, then it must be
authenticated.
+pub const AUTH: u32 = bindings::drm_ioctl_flags_DRM_AUTH;
+
+/// This must be set for any ioctl which can change the modeset or display
state. Userspace must
+/// call the ioctl through a primary node, while it is the active master.
+///
+/// Note that read-only modeset ioctl can also be called by unauthenticated
clients, or when a
+/// master is not the currently active one.
+pub const MASTER: u32 = bindings::drm_ioctl_flags_DRM_MASTER;
+
+/// Anything that could potentially wreak a master file descriptor needs to
have this flag set.
+///
+/// Current that?s only for the SETMASTER and DROPMASTER ioctl, which e.g.
logind can call to
+/// force a non-behaving master (display compositor) into compliance.
+///
+/// This is equivalent to callers with the SYSADMIN capability.
+pub const ROOT_ONLY: u32 = bindings::drm_ioctl_flags_DRM_ROOT_ONLY;
+
+/// This is used for all ioctl needed for rendering only, for drivers which
support render nodes.
+/// This should be all new render drivers, and hence it should be always set
for any ioctl with
+/// `AUTH` set. Note though that read-only query ioctl might have this set, but
have not set
+/// DRM_AUTH because they do not require authentication.
+pub const RENDER_ALLOW: u32 = bindings::drm_ioctl_flags_DRM_RENDER_ALLOW;
+
+/// Internal structures used by the `declare_drm_ioctls!{}` macro. Do not use
directly.
+#[doc(hidden)]
+pub mod internal {
+    pub use bindings::drm_device;
+    pub use bindings::drm_file;
+    pub use bindings::drm_ioctl_desc;
+}
+
+/// Declare the DRM ioctls for a driver.
+///
+/// Each entry in the list should have the form:
+///
+/// `(ioctl_number, argument_type, flags, user_callback),`
+///
+/// `argument_type` is the type name within the `bindings` crate.
+/// `user_callback` should have the following prototype:
+///
+/// ```ignore
+/// fn foo(device: &kernel::drm::device::Device<Self>,
+///        data: &mut bindings::argument_type,
+///        file: &kernel::drm::file::File<Self::File>,
+/// )
+/// ```
+/// where `Self` is the drm::drv::Driver implementation these ioctls are being
declared within.
+///
+/// # Examples
+///
+/// ```ignore
+/// kernel::declare_drm_ioctls! {
+///     (FOO_GET_PARAM, drm_foo_get_param, ioctl::RENDER_ALLOW,
my_get_param_handler),
+/// }
+/// ```
+///
+#[macro_export]
+macro_rules! declare_drm_ioctls {
+    ( $(($cmd:ident, $struct:ident, $flags:expr, $func:expr)),* $(,)? ) => {
+        const IOCTLS: &'static [$crate::drm::ioctl::DrmIoctlDescriptor]
= {
+            use $crate::uapi::*;
+            const _:() = {
+                let i: u32 = $crate::uapi::DRM_COMMAND_BASE;
+                // Assert that all the IOCTLs are in the right order and there
are no gaps,
+                // and that the sizeof of the specified type is correct.
+                $(
+                    let cmd: u32 = $crate::macros::concat_idents!(DRM_IOCTL_,
$cmd);
+                    ::core::assert!(i == $crate::ioctl::_IOC_NR(cmd));
+                   
::core::assert!(core::mem::size_of::<$crate::uapi::$struct>() =+          
$crate::ioctl::_IOC_SIZE(cmd));
+                    let i: u32 = i + 1;
+                )*
+            };
+
+            let ioctls = &[$(
+                $crate::drm::ioctl::internal::drm_ioctl_desc {
+                    cmd: $crate::macros::concat_idents!(DRM_IOCTL_, $cmd) as
u32,
+                    func: {
+                        #[allow(non_snake_case)]
+                        unsafe extern "C" fn $cmd(
+                                raw_dev: *mut
$crate::drm::ioctl::internal::drm_device,
+                                raw_data: *mut ::core::ffi::c_void,
+                                raw_file_priv: *mut
$crate::drm::ioctl::internal::drm_file,
+                        ) -> core::ffi::c_int {
+                            // SAFETY: The DRM core ensures the device lives
while callbacks are
+                            // being called.
+                            //
+                            // FIXME: Currently there is nothing enforcing that
the types of the
+                            // dev/file match the current driver these ioctls
are being declared
+                            // for, and it's not clear how to enforce this
within the type system.
+                            let dev =
$crate::drm::device::Device::borrow(raw_dev);
+                            // SAFETY: This is just the ioctl argument, which
hopefully has the
+                            // right type (we've done our best checking the
size).
+                            let data = unsafe { &mut *(raw_data as *mut
$crate::uapi::$struct) };
+                            // SAFETY: This is just the DRM file structure
+                            let file = unsafe {
$crate::drm::file::File::from_raw(raw_file_priv) };
+
+                            match $func(dev, data, &file) {
+                                Err(e) => e.to_errno(),
+                                Ok(i) => i.try_into()
+                                           
.unwrap_or($crate::error::code::ERANGE.to_errno()),
+                            }
+                        }
+                        Some($cmd)
+                    },
+                    flags: $flags,
+                    name:
$crate::c_str!(::core::stringify!($cmd)).as_char_ptr(),
+                }
+            ),*];
+            ioctls
+        };
+    };
+}
diff --git a/rust/kernel/drm/mod.rs b/rust/kernel/drm/mod.rs
new file mode 100644
index 000000000000..9ec6d7cbcaf3
--- /dev/null
+++ b/rust/kernel/drm/mod.rs
@@ -0,0 +1,5 @@
+// SPDX-License-Identifier: GPL-2.0 OR MIT
+
+//! DRM subsystem abstractions.
+
+pub mod ioctl;
diff --git a/rust/kernel/lib.rs b/rust/kernel/lib.rs
index 4a02946dbbd9..5a68b9a5fe03 100644
--- a/rust/kernel/lib.rs
+++ b/rust/kernel/lib.rs
@@ -33,6 +33,8 @@
 pub mod device_id;
 pub mod devres;
 pub mod driver;
+#[cfg(CONFIG_DRM = "y")]
+pub mod drm;
 pub mod error;
 #[cfg(CONFIG_RUST_FW_LOADER_ABSTRACTIONS)]
 pub mod firmware;
diff --git a/rust/uapi/uapi_helper.h b/rust/uapi/uapi_helper.h
index 08f5e9334c9e..ed42a456da2e 100644
--- a/rust/uapi/uapi_helper.h
+++ b/rust/uapi/uapi_helper.h
@@ -7,5 +7,6 @@
  */
 
 #include <uapi/asm-generic/ioctl.h>
+#include <uapi/drm/drm.h>
 #include <uapi/linux/mii.h>
 #include <uapi/linux/ethtool.h>
-- 
2.45.1

Danilo Krummrich

2024-Jun-18 23:31 UTC

head link

[PATCH v2 2/8] rust: Add a Sealed trait

From: Asahi Lina <lina at asahilina.net>

Some traits exposed by the kernel crate may not be intended to be
implemented by downstream modules. Add a Sealed trait to allow avoiding
this using the sealed trait pattern.

Signed-off-by: Asahi Lina <lina at asahilina.net>
Signed-off-by: Danilo Krummrich <dakr at redhat.com>
---
 rust/kernel/lib.rs | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/rust/kernel/lib.rs b/rust/kernel/lib.rs
index 5a68b9a5fe03..d83c4c58834f 100644
--- a/rust/kernel/lib.rs
+++ b/rust/kernel/lib.rs
@@ -68,6 +68,11 @@
 #[doc(hidden)]
 pub use build_error::build_error;
 
+pub(crate) mod private {
+    #[allow(unreachable_pub)]
+    pub trait Sealed {}
+}
+
 /// Prefix to appear before log messages printed from within the `kernel`
crate.
 const __LOG_PREFIX: &[u8] = b"rust_kernel\0";
 
-- 
2.45.1

Danilo Krummrich

2024-Jun-18 23:31 UTC

head link

[PATCH v2 3/8] rust: drm: add driver abstractions

Implement the DRM driver abstractions.

The `Driver` trait provides the interface to the actual driver to fill
in the driver specific data, such as the `DriverInfo`, driver features
and IOCTLs.

Co-developed-by: Asahi Lina <lina at asahilina.net>
Signed-off-by: Asahi Lina <lina at asahilina.net>
Signed-off-by: Danilo Krummrich <dakr at redhat.com>
---
 rust/bindings/bindings_helper.h |   1 +
 rust/kernel/drm/drv.rs          | 141 ++++++++++++++++++++++++++++++++
 rust/kernel/drm/mod.rs          |   1 +
 3 files changed, 143 insertions(+)
 create mode 100644 rust/kernel/drm/drv.rs

diff --git a/rust/bindings/bindings_helper.h b/rust/bindings/bindings_helper.h
index ed25b686748e..dc19cb789536 100644
--- a/rust/bindings/bindings_helper.h
+++ b/rust/bindings/bindings_helper.h
@@ -6,6 +6,7 @@
  * Sorted alphabetically.
  */
 
+#include <drm/drm_drv.h>
 #include <drm/drm_ioctl.h>
 #include <kunit/test.h>
 #include <linux/errname.h>
diff --git a/rust/kernel/drm/drv.rs b/rust/kernel/drm/drv.rs
new file mode 100644
index 000000000000..cd594a32f9e4
--- /dev/null
+++ b/rust/kernel/drm/drv.rs
@@ -0,0 +1,141 @@
+// SPDX-License-Identifier: GPL-2.0 OR MIT
+
+//! DRM driver core.
+//!
+//! C header:
[`include/linux/drm/drm_drv.h`](srctree/include/linux/drm/drm_drv.h)
+
+use crate::{bindings, drm, private::Sealed, str::CStr, types::ForeignOwnable};
+use macros::vtable;
+
+/// Driver use the GEM memory manager. This should be set for all modern
drivers.
+pub const FEAT_GEM: u32 = bindings::drm_driver_feature_DRIVER_GEM;
+/// Driver supports mode setting interfaces (KMS).
+pub const FEAT_MODESET: u32 = bindings::drm_driver_feature_DRIVER_MODESET;
+/// Driver supports dedicated render nodes.
+pub const FEAT_RENDER: u32 = bindings::drm_driver_feature_DRIVER_RENDER;
+/// Driver supports the full atomic modesetting userspace API.
+///
+/// Drivers which only use atomic internally, but do not support the full
userspace API (e.g. not
+/// all properties converted to atomic, or multi-plane updates are not
guaranteed to be tear-free)
+/// should not set this flag.
+pub const FEAT_ATOMIC: u32 = bindings::drm_driver_feature_DRIVER_ATOMIC;
+/// Driver supports DRM sync objects for explicit synchronization of command
submission.
+pub const FEAT_SYNCOBJ: u32 = bindings::drm_driver_feature_DRIVER_SYNCOBJ;
+/// Driver supports the timeline flavor of DRM sync objects for explicit
synchronization of command
+/// submission.
+pub const FEAT_SYNCOBJ_TIMELINE: u32 =
bindings::drm_driver_feature_DRIVER_SYNCOBJ_TIMELINE;
+/// Driver supports compute acceleration devices. This flag is mutually
exclusive with `FEAT_RENDER`
+/// and `FEAT_MODESET`. Devices that support both graphics and compute
acceleration should be
+/// handled by two drivers that are connected using auxiliary bus.
+pub const FEAT_COMPUTE_ACCEL: u32 =
bindings::drm_driver_feature_DRIVER_COMPUTE_ACCEL;
+/// Driver supports user defined GPU VA bindings for GEM objects.
+pub const FEAT_GEM_GPUVA: u32 = bindings::drm_driver_feature_DRIVER_GEM_GPUVA;
+/// Driver supports and requires cursor hotspot information in the cursor plane
(e.g. cursor plane
+/// has to actually track the mouse cursor and the clients are required to set
hotspot in order for
+/// the cursor planes to work correctly).
+pub const FEAT_CURSOR_HOTSPOT: u32 =
bindings::drm_driver_feature_DRIVER_CURSOR_HOTSPOT;
+
+/// Information data for a DRM Driver.
+pub struct DriverInfo {
+    /// Driver major version.
+    pub major: i32,
+    /// Driver minor version.
+    pub minor: i32,
+    /// Driver patchlevel version.
+    pub patchlevel: i32,
+    /// Driver name.
+    pub name: &'static CStr,
+    /// Driver description.
+    pub desc: &'static CStr,
+    /// Driver date.
+    pub date: &'static CStr,
+}
+
+/// Internal memory management operation set, normally created by memory
managers (e.g. GEM).
+///
+/// See `kernel::drm::gem` and `kernel::drm::gem::shmem`.
+pub struct AllocOps {
+    pub(crate) gem_create_object: Option<
+        unsafe extern "C" fn(
+            dev: *mut bindings::drm_device,
+            size: usize,
+        ) -> *mut bindings::drm_gem_object,
+    >,
+    pub(crate) prime_handle_to_fd: Option<
+        unsafe extern "C" fn(
+            dev: *mut bindings::drm_device,
+            file_priv: *mut bindings::drm_file,
+            handle: u32,
+            flags: u32,
+            prime_fd: *mut core::ffi::c_int,
+        ) -> core::ffi::c_int,
+    >,
+    pub(crate) prime_fd_to_handle: Option<
+        unsafe extern "C" fn(
+            dev: *mut bindings::drm_device,
+            file_priv: *mut bindings::drm_file,
+            prime_fd: core::ffi::c_int,
+            handle: *mut u32,
+        ) -> core::ffi::c_int,
+    >,
+    pub(crate) gem_prime_import: Option<
+        unsafe extern "C" fn(
+            dev: *mut bindings::drm_device,
+            dma_buf: *mut bindings::dma_buf,
+        ) -> *mut bindings::drm_gem_object,
+    >,
+    pub(crate) gem_prime_import_sg_table: Option<
+        unsafe extern "C" fn(
+            dev: *mut bindings::drm_device,
+            attach: *mut bindings::dma_buf_attachment,
+            sgt: *mut bindings::sg_table,
+        ) -> *mut bindings::drm_gem_object,
+    >,
+    pub(crate) dumb_create: Option<
+        unsafe extern "C" fn(
+            file_priv: *mut bindings::drm_file,
+            dev: *mut bindings::drm_device,
+            args: *mut bindings::drm_mode_create_dumb,
+        ) -> core::ffi::c_int,
+    >,
+    pub(crate) dumb_map_offset: Option<
+        unsafe extern "C" fn(
+            file_priv: *mut bindings::drm_file,
+            dev: *mut bindings::drm_device,
+            handle: u32,
+            offset: *mut u64,
+        ) -> core::ffi::c_int,
+    >,
+}
+
+/// Trait for memory manager implementations. Implemented internally.
+pub trait AllocImpl: Sealed {
+    /// The C callback operations for this memory manager.
+    const ALLOC_OPS: AllocOps;
+}
+
+/// The DRM `Driver` trait.
+///
+/// This trait must be implemented by drivers in order to create a `struct
drm_device` and `struct
+/// drm_driver` to be registered in the DRM subsystem.
+#[vtable]
+pub trait Driver {
+    /// Context data associated with the DRM driver
+    ///
+    /// Determines the type of the context data passed to each of the methods
of the trait.
+    type Data: ForeignOwnable + Sync + Send;
+
+    /// The type used to manage memory for this driver.
+    ///
+    /// Should be either `drm::gem::Object<T>` or
`drm::gem::shmem::Object<T>`.
+    type Object: AllocImpl;
+
+    /// Driver metadata
+    const INFO: DriverInfo;
+
+    /// Feature flags
+    const FEATURES: u32;
+
+    /// IOCTL list. See `kernel::drm::ioctl::declare_drm_ioctls!{}`.
+    const IOCTLS: &'static [drm::ioctl::DrmIoctlDescriptor];
+}
diff --git a/rust/kernel/drm/mod.rs b/rust/kernel/drm/mod.rs
index 9ec6d7cbcaf3..d987c56b3cec 100644
--- a/rust/kernel/drm/mod.rs
+++ b/rust/kernel/drm/mod.rs
@@ -2,4 +2,5 @@
 
 //! DRM subsystem abstractions.
 
+pub mod drv;
 pub mod ioctl;
-- 
2.45.1

Danilo Krummrich

2024-Jun-18 23:31 UTC

head link

[PATCH v2 4/8] rust: drm: add device abstraction

Implement the abstraction for a `struct drm_device`.

A `drm::device::Device` creates a static const `struct drm_driver` filled
with the data from the `drm::drv::Driver` trait implementation of the
actual driver creating the `drm::device::Device`.

Co-developed-by: Asahi Lina <lina at asahilina.net>
Signed-off-by: Asahi Lina <lina at asahilina.net>
Signed-off-by: Danilo Krummrich <dakr at redhat.com>
---
 rust/bindings/bindings_helper.h |   1 +
 rust/kernel/drm/device.rs       | 180 ++++++++++++++++++++++++++++++++
 rust/kernel/drm/mod.rs          |   1 +
 3 files changed, 182 insertions(+)
 create mode 100644 rust/kernel/drm/device.rs

diff --git a/rust/bindings/bindings_helper.h b/rust/bindings/bindings_helper.h
index dc19cb789536..1d12ee7d3c97 100644
--- a/rust/bindings/bindings_helper.h
+++ b/rust/bindings/bindings_helper.h
@@ -6,6 +6,7 @@
  * Sorted alphabetically.
  */
 
+#include <drm/drm_device.h>
 #include <drm/drm_drv.h>
 #include <drm/drm_ioctl.h>
 #include <kunit/test.h>
diff --git a/rust/kernel/drm/device.rs b/rust/kernel/drm/device.rs
new file mode 100644
index 000000000000..c62516f79221
--- /dev/null
+++ b/rust/kernel/drm/device.rs
@@ -0,0 +1,180 @@
+// SPDX-License-Identifier: GPL-2.0 OR MIT
+
+//! DRM device.
+//!
+//! C header:
[`include/linux/drm/drm_device.h`](srctree/include/linux/drm/drm_device.h)
+
+use crate::{
+    bindings, device, drm,
+    drm::drv::AllocImpl,
+    error::code::*,
+    error::from_err_ptr,
+    error::Result,
+    types::{ARef, AlwaysRefCounted, ForeignOwnable, Opaque},
+};
+use core::{ffi::c_void, marker::PhantomData, ptr::NonNull};
+
+#[cfg(CONFIG_DRM_LEGACY)]
+macro_rules! drm_legacy_fields {
+    ( $($field:ident: $val:expr),* $(,)? ) => {
+        bindings::drm_driver {
+            $( $field: $val ),*,
+            firstopen: None,
+            preclose: None,
+            dma_ioctl: None,
+            dma_quiescent: None,
+            context_dtor: None,
+            irq_handler: None,
+            irq_preinstall: None,
+            irq_postinstall: None,
+            irq_uninstall: None,
+            get_vblank_counter: None,
+            enable_vblank: None,
+            disable_vblank: None,
+            dev_priv_size: 0,
+        }
+    }
+}
+
+#[cfg(not(CONFIG_DRM_LEGACY))]
+macro_rules! drm_legacy_fields {
+    ( $($field:ident: $val:expr),* $(,)? ) => {
+        bindings::drm_driver {
+            $( $field: $val ),*
+        }
+    }
+}
+
+/// A typed DRM device with a specific `drm::drv::Driver` implementation. The
device is always
+/// reference-counted.
+///
+/// # Invariants
+///
+/// `drm_dev_release()` can be called from any non-atomic context.
+#[repr(transparent)]
+pub struct Device<T:
drm::drv::Driver>(Opaque<bindings::drm_device>, PhantomData<T>);
+
+impl<T: drm::drv::Driver> Device<T> {
+    const VTABLE: bindings::drm_driver = drm_legacy_fields! {
+        load: None,
+        open: None, // TODO: File abstraction
+        postclose: None, // TODO: File abstraction
+        lastclose: None,
+        unload: None,
+        release: Some(Self::release),
+        master_set: None,
+        master_drop: None,
+        debugfs_init: None,
+        gem_create_object: T::Object::ALLOC_OPS.gem_create_object,
+        prime_handle_to_fd: T::Object::ALLOC_OPS.prime_handle_to_fd,
+        prime_fd_to_handle: T::Object::ALLOC_OPS.prime_fd_to_handle,
+        gem_prime_import: T::Object::ALLOC_OPS.gem_prime_import,
+        gem_prime_import_sg_table:
T::Object::ALLOC_OPS.gem_prime_import_sg_table,
+        dumb_create: T::Object::ALLOC_OPS.dumb_create,
+        dumb_map_offset: T::Object::ALLOC_OPS.dumb_map_offset,
+        show_fdinfo: None,
+
+        major: T::INFO.major,
+        minor: T::INFO.minor,
+        patchlevel: T::INFO.patchlevel,
+        name: T::INFO.name.as_char_ptr() as *mut _,
+        desc: T::INFO.desc.as_char_ptr() as *mut _,
+        date: T::INFO.date.as_char_ptr() as *mut _,
+
+        driver_features: T::FEATURES,
+        ioctls: T::IOCTLS.as_ptr(),
+        num_ioctls: T::IOCTLS.len() as i32,
+        fops: core::ptr::null_mut() as _,
+    };
+
+    /// Create a new `drm::device::Device` for a `drm::drv::Driver`.
+    pub fn new(dev: &device::Device, data: T::Data) ->
Result<ARef<Self>> {
+        // SAFETY: `dev` is valid by its type invarants; `VTABLE`, as a `const`
is pinned to the
+        // read-only section of the compilation.
+        let raw_drm = unsafe { bindings::drm_dev_alloc(&Self::VTABLE,
dev.as_raw()) };
+        let raw_drm = NonNull::new(from_err_ptr(raw_drm)? as *mut
_).ok_or(ENOMEM)?;
+
+        let data_ptr = <T::Data as ForeignOwnable>::into_foreign(data);
+
+        // SAFETY: The reference count is one, and now we take ownership of
that reference as a
+        // drm::device::Device.
+        let drm = unsafe { ARef::<Self>::from_raw(raw_drm) };
+
+        // SAFETY: Safe as we set `dev_private` once at device creation.
+        unsafe { drm.set_raw_data(data_ptr) };
+
+        Ok(drm)
+    }
+
+    pub(crate) fn as_raw(&self) -> *mut bindings::drm_device {
+        self.0.get()
+    }
+
+    /// Not intended to be called externally, except via declare_drm_ioctls!()
+    ///
+    /// # Safety
+    ///
+    /// Callers must ensure that `ptr` is valid, non-null, and has a non-zero
reference count,
+    /// i.e. it must be ensured that the reference count of the C `struct
drm_device` `ptr` points
+    /// to can't drop to zero, for the duration of this function call and
the entire duration when
+    /// the returned reference exists.
+    #[doc(hidden)]
+    pub unsafe fn borrow<'a>(ptr: *const bindings::drm_device) ->
&'a Self {
+        // SAFETY: Safe by the safety requirements of this function.
+        unsafe { &*ptr.cast() }
+    }
+
+    pub(crate) fn raw_data(&self) -> *const c_void {
+        // SAFETY: `self` is guaranteed to hold a valid `bindings::drm_device`
pointer.
+        unsafe { *self.as_raw() }.dev_private
+    }
+
+    // SAFETY: Must be called only once after device creation.
+    unsafe fn set_raw_data(&self, ptr: *const c_void) {
+        // SAFETY: Safe as by the safety precondition.
+        unsafe { &mut *self.as_raw() }.dev_private = ptr as _;
+    }
+
+    /// Returns a borrowed reference to the user data associated with this
Device.
+    pub fn data(&self) -> <T::Data as
ForeignOwnable>::Borrowed<'_> {
+        // SAFETY: `dev_private` is always set at device creation.
+        unsafe { T::Data::borrow(self.raw_data()) }
+    }
+
+    unsafe extern "C" fn release(drm: *mut bindings::drm_device) {
+        // SAFETY: Guaranteed to be a valid pointer to a `struct drm_device`.
+        let drm = unsafe { Self::borrow(drm) };
+
+        // SAFETY: `Self::data` is always converted and set on device creation.
+        unsafe { <T::Data as
ForeignOwnable>::from_foreign(drm.raw_data()) };
+    }
+}
+
+// SAFETY: DRM device objects are always reference counted and the get/put
functions
+// satisfy the requirements.
+unsafe impl<T: drm::drv::Driver> AlwaysRefCounted for Device<T> {
+    fn inc_ref(&self) {
+        // SAFETY: The existence of a shared reference guarantees that the
refcount is non-zero.
+        unsafe { bindings::drm_dev_get(self.as_raw()) };
+    }
+
+    unsafe fn dec_ref(obj: NonNull<Self>) {
+        // SAFETY: The safety requirements guarantee that the refcount is
non-zero.
+        unsafe { bindings::drm_dev_put(obj.cast().as_ptr()) };
+    }
+}
+
+impl<T: drm::drv::Driver> AsRef<device::Device> for Device<T>
{
+    fn as_ref(&self) -> &device::Device {
+        // SAFETY: `bindings::drm_device::dev` is valid as long as the DRM
device itself is valid,
+        // which is guaranteed by the type invariant.
+        unsafe { device::Device::as_ref((*self.as_raw()).dev) }
+    }
+}
+
+// SAFETY: As by the type invariant `Device` can be sent to any thread.
+unsafe impl<T: drm::drv::Driver> Send for Device<T> {}
+
+// SAFETY: `Device` can be shared among threads because all immutable methods
are protected by the
+// synchronization in `struct drm_device`.
+unsafe impl<T: drm::drv::Driver> Sync for Device<T> {}
diff --git a/rust/kernel/drm/mod.rs b/rust/kernel/drm/mod.rs
index d987c56b3cec..69376b3c6db9 100644
--- a/rust/kernel/drm/mod.rs
+++ b/rust/kernel/drm/mod.rs
@@ -2,5 +2,6 @@
 
 //! DRM subsystem abstractions.
 
+pub mod device;
 pub mod drv;
 pub mod ioctl;
-- 
2.45.1

Danilo Krummrich

2024-Jun-18 23:31 UTC

head link

[PATCH v2 5/8] rust: drm: add DRM driver registration

Implement the DRM driver `Registration`.

The `Registration` structure is responsible to register and unregister a
DRM driver. It makes use of the `Devres` container in order to allow the
`Registration` to be owned by devres, such that it is automatically
dropped (and the DRM driver unregistered) once the parent device is
unbound.

Co-developed-by: Asahi Lina <lina at asahilina.net>
Signed-off-by: Asahi Lina <lina at asahilina.net>
Signed-off-by: Danilo Krummrich <dakr at redhat.com>
---
 rust/kernel/drm/drv.rs | 57 +++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 56 insertions(+), 1 deletion(-)

diff --git a/rust/kernel/drm/drv.rs b/rust/kernel/drm/drv.rs
index cd594a32f9e4..ebb79a8c90ee 100644
--- a/rust/kernel/drm/drv.rs
+++ b/rust/kernel/drm/drv.rs
@@ -4,7 +4,16 @@
 //!
 //! C header:
[`include/linux/drm/drm_drv.h`](srctree/include/linux/drm/drm_drv.h)
 
-use crate::{bindings, drm, private::Sealed, str::CStr, types::ForeignOwnable};
+use crate::{
+    alloc::flags::*,
+    bindings,
+    devres::Devres,
+    drm,
+    error::{Error, Result},
+    private::Sealed,
+    str::CStr,
+    types::{ARef, ForeignOwnable},
+};
 use macros::vtable;
 
 /// Driver use the GEM memory manager. This should be set for all modern
drivers.
@@ -139,3 +148,49 @@ pub trait Driver {
     /// IOCTL list. See `kernel::drm::ioctl::declare_drm_ioctls!{}`.
     const IOCTLS: &'static [drm::ioctl::DrmIoctlDescriptor];
 }
+
+/// The registration type of a `drm::device::Device`.
+///
+/// Once the `Registration` structure is dropped, the device is unregistered.
+pub struct Registration<T:
Driver>(ARef<drm::device::Device<T>>);
+
+impl<T: Driver> Registration<T> {
+    /// Creates a new [`Registration`] and registers it.
+    pub fn new(drm: ARef<drm::device::Device<T>>, flags: usize)
-> Result<Self> {
+        // SAFETY: Safe by the invariants of `drm::device::Device`.
+        let ret = unsafe { bindings::drm_dev_register(drm.as_raw(), flags as
u64) };
+        if ret < 0 {
+            return Err(Error::from_errno(ret));
+        }
+
+        Ok(Self(drm))
+    }
+
+    /// Same as [`Registration::new`}, but transfers ownership of the
[`Registration`] to `Devres`.
+    pub fn new_foreign_owned(drm: ARef<drm::device::Device<T>>,
flags: usize) -> Result {
+        let reg = Registration::<T>::new(drm.clone(), flags)?;
+
+        Devres::new_foreign_owned(drm.as_ref(), reg, GFP_KERNEL)
+    }
+
+    /// Returns a reference to the `Device` instance for this registration.
+    pub fn device(&self) -> &drm::device::Device<T> {
+        &self.0
+    }
+}
+
+// SAFETY: `Registration` doesn't offer any methods or access to fields
when shared between
+// threads, hence it's safe to share it.
+unsafe impl<T: Driver> Sync for Registration<T> {}
+
+// SAFETY: Registration with and unregistration from the DRM subsystem can
happen from any thread.
+unsafe impl<T: Driver> Send for Registration<T> {}
+
+impl<T: Driver> Drop for Registration<T> {
+    /// Removes the registration from the kernel if it has completed
successfully before.
+    fn drop(&mut self) {
+        // SAFETY: Safe by the invariant of
`ARef<drm::device::Device<T>>`. The existance of this
+        // `Registration` also guarantees the this `drm::device::Device` is
actually registered.
+        unsafe { bindings::drm_dev_unregister(self.0.as_raw()) };
+    }
+}
-- 
2.45.1

Danilo Krummrich

2024-Jun-18 23:31 UTC

head link

[PATCH v2 6/8] rust: drm: file: Add File abstraction

From: Asahi Lina <lina at asahilina.net>

A DRM File is the DRM counterpart to a kernel file structure,
representing an open DRM file descriptor. Add a Rust abstraction to
allow drivers to implement their own File types that implement the
DriverFile trait.

Signed-off-by: Asahi Lina <lina at asahilina.net>
Signed-off-by: Danilo Krummrich <dakr at redhat.com>
---
 rust/bindings/bindings_helper.h |   1 +
 rust/kernel/drm/device.rs       |   4 +-
 rust/kernel/drm/drv.rs          |   3 +
 rust/kernel/drm/file.rs         | 116 ++++++++++++++++++++++++++++++++
 rust/kernel/drm/mod.rs          |   1 +
 5 files changed, 123 insertions(+), 2 deletions(-)
 create mode 100644 rust/kernel/drm/file.rs

diff --git a/rust/bindings/bindings_helper.h b/rust/bindings/bindings_helper.h
index 1d12ee7d3c97..3f17961b4c3b 100644
--- a/rust/bindings/bindings_helper.h
+++ b/rust/bindings/bindings_helper.h
@@ -8,6 +8,7 @@
 
 #include <drm/drm_device.h>
 #include <drm/drm_drv.h>
+#include <drm/drm_file.h>
 #include <drm/drm_ioctl.h>
 #include <kunit/test.h>
 #include <linux/errname.h>
diff --git a/rust/kernel/drm/device.rs b/rust/kernel/drm/device.rs
index c62516f79221..c6ed8d86700b 100644
--- a/rust/kernel/drm/device.rs
+++ b/rust/kernel/drm/device.rs
@@ -57,8 +57,8 @@ macro_rules! drm_legacy_fields {
 impl<T: drm::drv::Driver> Device<T> {
     const VTABLE: bindings::drm_driver = drm_legacy_fields! {
         load: None,
-        open: None, // TODO: File abstraction
-        postclose: None, // TODO: File abstraction
+        open: Some(drm::file::open_callback::<T::File>),
+        postclose: Some(drm::file::postclose_callback::<T::File>),
         lastclose: None,
         unload: None,
         release: Some(Self::release),
diff --git a/rust/kernel/drm/drv.rs b/rust/kernel/drm/drv.rs
index ebb79a8c90ee..895409f04664 100644
--- a/rust/kernel/drm/drv.rs
+++ b/rust/kernel/drm/drv.rs
@@ -139,6 +139,9 @@ pub trait Driver {
     /// Should be either `drm::gem::Object<T>` or
`drm::gem::shmem::Object<T>`.
     type Object: AllocImpl;
 
+    /// The type used to represent a DRM File (client)
+    type File: drm::file::DriverFile;
+
     /// Driver metadata
     const INFO: DriverInfo;
 
diff --git a/rust/kernel/drm/file.rs b/rust/kernel/drm/file.rs
new file mode 100644
index 000000000000..0b6366734c61
--- /dev/null
+++ b/rust/kernel/drm/file.rs
@@ -0,0 +1,116 @@
+// SPDX-License-Identifier: GPL-2.0 OR MIT
+
+//! DRM File objects.
+//!
+//! C header:
[`include/linux/drm/drm_file.h`](srctree/include/linux/drm/drm_file.h)
+
+use crate::{bindings, drm, error::Result};
+use alloc::boxed::Box;
+use core::marker::PhantomData;
+use core::pin::Pin;
+
+/// Trait that must be implemented by DRM drivers to represent a DRM File (a
client instance).
+pub trait DriverFile {
+    /// The parent `Driver` implementation for this `DriverFile`.
+    type Driver: drm::drv::Driver;
+
+    /// Open a new file (called when a client opens the DRM device).
+    fn open(device: &drm::device::Device<Self::Driver>) ->
Result<Pin<Box<Self>>>;
+}
+
+/// An open DRM File.
+///
+/// # Invariants
+/// `raw` is a valid pointer to a `drm_file` struct.
+#[repr(transparent)]
+pub struct File<T: DriverFile> {
+    raw: *mut bindings::drm_file,
+    _p: PhantomData<T>,
+}
+
+/// The open callback of a `struct drm_file`.
+pub(super) unsafe extern "C" fn open_callback<T: DriverFile>(
+    raw_dev: *mut bindings::drm_device,
+    raw_file: *mut bindings::drm_file,
+) -> core::ffi::c_int {
+    let drm = unsafe { drm::device::Device::borrow(raw_dev) };
+    // SAFETY: This reference won't escape this function
+    let file = unsafe { &mut *raw_file };
+
+    let inner = match T::open(drm) {
+        Err(e) => {
+            return e.to_errno();
+        }
+        Ok(i) => i,
+    };
+
+    // SAFETY: This pointer is treated as pinned, and the Drop guarantee is
upheld below.
+    file.driver_priv = Box::into_raw(unsafe { Pin::into_inner_unchecked(inner)
}) as *mut _;
+
+    0
+}
+
+/// The postclose callback of a `struct drm_file`.
+pub(super) unsafe extern "C" fn postclose_callback<T:
DriverFile>(
+    _raw_dev: *mut bindings::drm_device,
+    raw_file: *mut bindings::drm_file,
+) {
+    // SAFETY: This reference won't escape this function
+    let file = unsafe { &*raw_file };
+
+    // Drop the DriverFile
+    unsafe {
+        let _ = Box::from_raw(file.driver_priv as *mut T);
+    };
+}
+
+impl<T: DriverFile> File<T> {
+    // Not intended to be called externally, except via declare_drm_ioctls!()
+    #[doc(hidden)]
+    pub unsafe fn from_raw(raw_file: *mut bindings::drm_file) ->
File<T> {
+        File {
+            raw: raw_file,
+            _p: PhantomData,
+        }
+    }
+
+    #[allow(dead_code)]
+    /// Return the raw pointer to the underlying `drm_file`.
+    pub(super) fn raw(&self) -> *const bindings::drm_file {
+        self.raw
+    }
+
+    /// Return an immutable reference to the raw `drm_file` structure.
+    pub(super) fn file(&self) -> &bindings::drm_file {
+        unsafe { &*self.raw }
+    }
+
+    /// Return a pinned reference to the driver file structure.
+    pub fn inner(&self) -> Pin<&T> {
+        unsafe { Pin::new_unchecked(&*(self.file().driver_priv as *const
T)) }
+    }
+}
+
+impl<T: DriverFile> crate::private::Sealed for File<T> {}
+
+/// Generic trait to allow users that don't care about driver specifics to
accept any `File<T>`.
+///
+/// # Safety
+///
+/// Must only be implemented for `File<T>` and return the pointer,
following the normal invariants
+/// of that type.
+pub unsafe trait GenericFile: crate::private::Sealed {
+    /// Returns the raw const pointer to the `struct drm_file`
+    fn raw(&self) -> *const bindings::drm_file;
+    /// Returns the raw mut pointer to the `struct drm_file`
+    fn raw_mut(&mut self) -> *mut bindings::drm_file;
+}
+
+unsafe impl<T: DriverFile> GenericFile for File<T> {
+    fn raw(&self) -> *const bindings::drm_file {
+        self.raw
+    }
+    fn raw_mut(&mut self) -> *mut bindings::drm_file {
+        self.raw
+    }
+}
diff --git a/rust/kernel/drm/mod.rs b/rust/kernel/drm/mod.rs
index 69376b3c6db9..a767942d0b52 100644
--- a/rust/kernel/drm/mod.rs
+++ b/rust/kernel/drm/mod.rs
@@ -4,4 +4,5 @@
 
 pub mod device;
 pub mod drv;
+pub mod file;
 pub mod ioctl;
-- 
2.45.1

Danilo Krummrich

2024-Jun-18 23:31 UTC

head link

[PATCH v2 7/8] rust: drm: gem: Add GEM object abstraction

From: Asahi Lina <lina at asahilina.net>

The DRM GEM subsystem is the DRM memory management subsystem used by
most modern drivers. Add a Rust abstraction to allow Rust DRM driver
implementations to use it.

Signed-off-by: Asahi Lina <lina at asahilina.net>
Co-developed-by: Danilo Krummrich <dakr at redhat.com>
Signed-off-by: Danilo Krummrich <dakr at redhat.com>
---
 rust/bindings/bindings_helper.h |   1 +
 rust/helpers.c                  |  23 ++
 rust/kernel/drm/device.rs       |   4 +-
 rust/kernel/drm/drv.rs          |   2 +-
 rust/kernel/drm/gem/mod.rs      | 409 ++++++++++++++++++++++++++++++++
 rust/kernel/drm/mod.rs          |   1 +
 6 files changed, 438 insertions(+), 2 deletions(-)
 create mode 100644 rust/kernel/drm/gem/mod.rs

diff --git a/rust/bindings/bindings_helper.h b/rust/bindings/bindings_helper.h
index 3f17961b4c3b..e4ffc47da5ec 100644
--- a/rust/bindings/bindings_helper.h
+++ b/rust/bindings/bindings_helper.h
@@ -9,6 +9,7 @@
 #include <drm/drm_device.h>
 #include <drm/drm_drv.h>
 #include <drm/drm_file.h>
+#include <drm/drm_gem.h>
 #include <drm/drm_ioctl.h>
 #include <kunit/test.h>
 #include <linux/errname.h>
diff --git a/rust/helpers.c b/rust/helpers.c
index c7f90b457af5..5d138eb53fc6 100644
--- a/rust/helpers.c
+++ b/rust/helpers.c
@@ -20,6 +20,7 @@
  * Sorted alphabetically.
  */
 
+#include <drm/drm_gem.h>
 #include <kunit/test-bug.h>
 #include <linux/bug.h>
 #include <linux/build_bug.h>
@@ -311,6 +312,28 @@ u64 rust_helper_pci_resource_len(struct pci_dev *pdev, int
barnr)
 	return pci_resource_len(pdev, barnr);
 }
 
+#ifdef CONFIG_DRM
+
+void rust_helper_drm_gem_object_get(struct drm_gem_object *obj)
+{
+	drm_gem_object_get(obj);
+}
+EXPORT_SYMBOL_GPL(rust_helper_drm_gem_object_get);
+
+void rust_helper_drm_gem_object_put(struct drm_gem_object *obj)
+{
+	drm_gem_object_put(obj);
+}
+EXPORT_SYMBOL_GPL(rust_helper_drm_gem_object_put);
+
+__u64 rust_helper_drm_vma_node_offset_addr(struct drm_vma_offset_node *node)
+{
+	return drm_vma_node_offset_addr(node);
+}
+EXPORT_SYMBOL_GPL(rust_helper_drm_vma_node_offset_addr);
+
+#endif
+
 /*
  * `bindgen` binds the C `size_t` type as the Rust `usize` type, so we can
  * use it in contexts where Rust expects a `usize` like slice (array) indices.
diff --git a/rust/kernel/drm/device.rs b/rust/kernel/drm/device.rs
index c6ed8d86700b..2b687033caa2 100644
--- a/rust/kernel/drm/device.rs
+++ b/rust/kernel/drm/device.rs
@@ -84,9 +84,11 @@ impl<T: drm::drv::Driver> Device<T> {
         driver_features: T::FEATURES,
         ioctls: T::IOCTLS.as_ptr(),
         num_ioctls: T::IOCTLS.len() as i32,
-        fops: core::ptr::null_mut() as _,
+        fops: &Self::GEM_FOPS as _,
     };
 
+    const GEM_FOPS: bindings::file_operations = drm::gem::create_fops();
+
     /// Create a new `drm::device::Device` for a `drm::drv::Driver`.
     pub fn new(dev: &device::Device, data: T::Data) ->
Result<ARef<Self>> {
         // SAFETY: `dev` is valid by its type invarants; `VTABLE`, as a `const`
is pinned to the
diff --git a/rust/kernel/drm/drv.rs b/rust/kernel/drm/drv.rs
index 895409f04664..0cf3fb1cea53 100644
--- a/rust/kernel/drm/drv.rs
+++ b/rust/kernel/drm/drv.rs
@@ -118,7 +118,7 @@ pub struct AllocOps {
 }
 
 /// Trait for memory manager implementations. Implemented internally.
-pub trait AllocImpl: Sealed {
+pub trait AllocImpl: Sealed + drm::gem::IntoGEMObject {
     /// The C callback operations for this memory manager.
     const ALLOC_OPS: AllocOps;
 }
diff --git a/rust/kernel/drm/gem/mod.rs b/rust/kernel/drm/gem/mod.rs
new file mode 100644
index 000000000000..b5208fdf66c2
--- /dev/null
+++ b/rust/kernel/drm/gem/mod.rs
@@ -0,0 +1,409 @@
+// SPDX-License-Identifier: GPL-2.0 OR MIT
+
+//! DRM GEM API
+//!
+//! C header:
[`include/linux/drm/drm_gem.h`](srctree/include/linux/drm/drm_gem.h)
+
+use alloc::boxed::Box;
+
+use crate::{
+    alloc::flags::*,
+    bindings,
+    drm::{device, drv, file},
+    error::{to_result, Result},
+    prelude::*,
+};
+use core::{marker::PhantomPinned, mem, ops::Deref, ops::DerefMut};
+
+/// GEM object functions, which must be implemented by drivers.
+pub trait BaseDriverObject<T: BaseObject>: Sync + Send + Sized {
+    /// Create a new driver data object for a GEM object of a given size.
+    fn new(dev: &device::Device<T::Driver>, size: usize) -> impl
PinInit<Self, Error>;
+
+    /// Open a new handle to an existing object, associated with a File.
+    fn open(
+        _obj: &<<T as IntoGEMObject>::Driver as
drv::Driver>::Object,
+        _file: &file::File<<<T as IntoGEMObject>::Driver as
drv::Driver>::File>,
+    ) -> Result {
+        Ok(())
+    }
+
+    /// Close a handle to an existing object, associated with a File.
+    fn close(
+        _obj: &<<T as IntoGEMObject>::Driver as
drv::Driver>::Object,
+        _file: &file::File<<<T as IntoGEMObject>::Driver as
drv::Driver>::File>,
+    ) {
+    }
+}
+
+/// Trait that represents a GEM object subtype
+pub trait IntoGEMObject: Sized + crate::private::Sealed {
+    /// Owning driver for this type
+    type Driver: drv::Driver;
+
+    /// Returns a reference to the raw `drm_gem_object` structure, which must
be valid as long as
+    /// this owning object is valid.
+    fn gem_obj(&self) -> &bindings::drm_gem_object;
+
+    /// Converts a pointer to a `drm_gem_object` into a pointer to this type.
+    fn from_gem_obj(obj: *mut bindings::drm_gem_object) -> *mut Self;
+}
+
+/// Trait which must be implemented by drivers using base GEM objects.
+pub trait DriverObject: BaseDriverObject<Object<Self>> {
+    /// Parent `Driver` for this object.
+    type Driver: drv::Driver;
+}
+
+unsafe extern "C" fn free_callback<T: DriverObject>(obj: *mut
bindings::drm_gem_object) {
+    // SAFETY: All of our objects are Object<T>.
+    let this = unsafe { crate::container_of!(obj, Object<T>, obj) } as
*mut Object<T>;
+
+    // SAFETY: The pointer we got has to be valid
+    unsafe { bindings::drm_gem_object_release(obj) };
+
+    // SAFETY: All of our objects are allocated via Box<>, and we're
in the
+    // free callback which guarantees this object has zero remaining
references,
+    // so we can drop it
+    unsafe {
+        let _ = Box::from_raw(this);
+    };
+}
+
+unsafe extern "C" fn open_callback<T: BaseDriverObject<U>,
U: BaseObject>(
+    raw_obj: *mut bindings::drm_gem_object,
+    raw_file: *mut bindings::drm_file,
+) -> core::ffi::c_int {
+    // SAFETY: The pointer we got has to be valid.
+    let file = unsafe {
+        file::File::<<<U as IntoGEMObject>::Driver as
drv::Driver>::File>::from_raw(raw_file)
+    };
+    let obj +        <<<U as IntoGEMObject>::Driver as
drv::Driver>::Object as IntoGEMObject>::from_gem_obj(
+            raw_obj,
+        );
+
+    // SAFETY: from_gem_obj() returns a valid pointer as long as the type is
+    // correct and the raw_obj we got is valid.
+    match T::open(unsafe { &*obj }, &file) {
+        Err(e) => e.to_errno(),
+        Ok(()) => 0,
+    }
+}
+
+unsafe extern "C" fn close_callback<T: BaseDriverObject<U>,
U: BaseObject>(
+    raw_obj: *mut bindings::drm_gem_object,
+    raw_file: *mut bindings::drm_file,
+) {
+    // SAFETY: The pointer we got has to be valid.
+    let file = unsafe {
+        file::File::<<<U as IntoGEMObject>::Driver as
drv::Driver>::File>::from_raw(raw_file)
+    };
+    let obj +        <<<U as IntoGEMObject>::Driver as
drv::Driver>::Object as IntoGEMObject>::from_gem_obj(
+            raw_obj,
+        );
+
+    // SAFETY: from_gem_obj() returns a valid pointer as long as the type is
+    // correct and the raw_obj we got is valid.
+    T::close(unsafe { &*obj }, &file);
+}
+
+impl<T: DriverObject> IntoGEMObject for Object<T> {
+    type Driver = T::Driver;
+
+    fn gem_obj(&self) -> &bindings::drm_gem_object {
+        &self.obj
+    }
+
+    fn from_gem_obj(obj: *mut bindings::drm_gem_object) -> *mut
Object<T> {
+        unsafe { crate::container_of!(obj, Object<T>, obj) as *mut
Object<T> }
+    }
+}
+
+/// Base operations shared by all GEM object classes
+pub trait BaseObject: IntoGEMObject {
+    /// Returns the size of the object in bytes.
+    fn size(&self) -> usize {
+        self.gem_obj().size
+    }
+
+    /// Creates a new reference to the object.
+    fn reference(&self) -> ObjectRef<Self> {
+        // SAFETY: Having a reference to an Object implies holding a GEM
reference
+        unsafe {
+            bindings::drm_gem_object_get(self.gem_obj() as *const _ as *mut _);
+        }
+        ObjectRef {
+            ptr: self as *const _,
+        }
+    }
+
+    /// Creates a new handle for the object associated with a given `File`
+    /// (or returns an existing one).
+    fn create_handle(
+        &self,
+        file: &file::File<<<Self as IntoGEMObject>::Driver as
drv::Driver>::File>,
+    ) -> Result<u32> {
+        let mut handle: u32 = 0;
+        // SAFETY: The arguments are all valid per the type invariants.
+        to_result(unsafe {
+            bindings::drm_gem_handle_create(
+                file.raw() as *mut _,
+                self.gem_obj() as *const _ as *mut _,
+                &mut handle,
+            )
+        })?;
+        Ok(handle)
+    }
+
+    /// Looks up an object by its handle for a given `File`.
+    fn lookup_handle(
+        file: &file::File<<<Self as IntoGEMObject>::Driver as
drv::Driver>::File>,
+        handle: u32,
+    ) -> Result<ObjectRef<Self>> {
+        // SAFETY: The arguments are all valid per the type invariants.
+        let ptr = unsafe { bindings::drm_gem_object_lookup(file.raw() as *mut
_, handle) };
+
+        if ptr.is_null() {
+            Err(ENOENT)
+        } else {
+            Ok(ObjectRef {
+                ptr: ptr as *const _,
+            })
+        }
+    }
+
+    /// Creates an mmap offset to map the object from userspace.
+    fn create_mmap_offset(&self) -> Result<u64> {
+        // SAFETY: The arguments are valid per the type invariant.
+        to_result(unsafe {
+            bindings::drm_gem_create_mmap_offset(self.gem_obj() as *const _ as
*mut _)
+        })?;
+        Ok(unsafe {
+            bindings::drm_vma_node_offset_addr(&self.gem_obj().vma_node as
*const _ as *mut _)
+        })
+    }
+}
+
+impl<T: IntoGEMObject> BaseObject for T {}
+
+/// A base GEM object.
+#[repr(C)]
+#[pin_data]
+pub struct Object<T: DriverObject> {
+    obj: bindings::drm_gem_object,
+    // The DRM core ensures the Device exists as long as its objects exist, so
we don't need to
+    // manage the reference count here.
+    dev: *const bindings::drm_device,
+    #[pin]
+    inner: T,
+    #[pin]
+    _p: PhantomPinned,
+}
+
+// SAFETY: This struct is safe to zero-initialize
+unsafe impl init::Zeroable for bindings::drm_gem_object {}
+
+impl<T: DriverObject> Object<T> {
+    /// The size of this object's structure.
+    pub const SIZE: usize = mem::size_of::<Self>();
+
+    const OBJECT_FUNCS: bindings::drm_gem_object_funcs =
bindings::drm_gem_object_funcs {
+        free: Some(free_callback::<T>),
+        open: Some(open_callback::<T, Object<T>>),
+        close: Some(close_callback::<T, Object<T>>),
+        print_info: None,
+        export: None,
+        pin: None,
+        unpin: None,
+        get_sg_table: None,
+        vmap: None,
+        vunmap: None,
+        mmap: None,
+        status: None,
+        vm_ops: core::ptr::null_mut(),
+        evict: None,
+        rss: None,
+    };
+
+    /// Create a new GEM object.
+    pub fn new(dev: &device::Device<T::Driver>, size: usize) ->
Result<Pin<UniqueObjectRef<Self>>> {
+        let obj: Pin<Box<Self>> = Box::pin_init(
+            try_pin_init!(Self {
+                // SAFETY: This struct is expected to be zero-initialized
+                obj: bindings::drm_gem_object {
+                    funcs: &Self::OBJECT_FUNCS,
+                    ..Default::default()
+                },
+                inner <- T::new(dev, size),
+                // SAFETY: The drm subsystem guarantees that the drm_device
will live as long as
+                // the GEM object lives, so we can conjure a reference out of
thin air.
+                dev: dev.as_raw(),
+                _p: PhantomPinned
+            }),
+            GFP_KERNEL,
+        )?;
+
+        to_result(unsafe {
+            bindings::drm_gem_object_init(dev.as_raw(), &obj.obj as *const
_ as *mut _, size)
+        })?;
+
+        // SAFETY: We never move out of self
+        let obj_ref = unsafe {
+            Pin::new_unchecked(UniqueObjectRef {
+                // SAFETY: We never move out of the Box
+                ptr: Box::leak(Pin::into_inner_unchecked(obj)),
+                _p: PhantomPinned,
+            })
+        };
+
+        Ok(obj_ref)
+    }
+
+    /// Returns the `Device` that owns this GEM object.
+    pub fn dev(&self) -> &device::Device<T::Driver> {
+        // SAFETY: The drm subsystem guarantees that the drm_device will live
as long as
+        // the GEM object lives, so we can just borrow from the raw pointer.
+        unsafe { device::Device::borrow(self.dev) }
+    }
+}
+
+impl<T: DriverObject> crate::private::Sealed for Object<T> {}
+
+impl<T: DriverObject> Deref for Object<T> {
+    type Target = T;
+
+    fn deref(&self) -> &Self::Target {
+        &self.inner
+    }
+}
+
+impl<T: DriverObject> DerefMut for Object<T> {
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        &mut self.inner
+    }
+}
+
+impl<T: DriverObject> drv::AllocImpl for Object<T> {
+    const ALLOC_OPS: drv::AllocOps = drv::AllocOps {
+        gem_create_object: None,
+        prime_handle_to_fd: None,
+        prime_fd_to_handle: None,
+        gem_prime_import: None,
+        gem_prime_import_sg_table: None,
+        dumb_create: None,
+        dumb_map_offset: None,
+    };
+}
+
+/// A reference-counted shared reference to a base GEM object.
+pub struct ObjectRef<T: IntoGEMObject> {
+    // Invariant: the pointer is valid and initialized, and this ObjectRef owns
a reference to it.
+    ptr: *const T,
+}
+
+impl<T: IntoGEMObject> ObjectRef<T> {
+    /// Downgrade this reference to a shared reference.
+    pub fn from_pinned_unique(pin: Pin<UniqueObjectRef<T>>) ->
Self {
+        // SAFETY: A (shared) `ObjectRef` doesn't need to be pinned, since
it doesn't allow us to
+        // optain a mutable reference.
+        let uq = unsafe { Pin::into_inner_unchecked(pin) };
+
+        uq.into_ref()
+    }
+}
+
+/// SAFETY: GEM object references are safe to share between threads.
+unsafe impl<T: IntoGEMObject> Send for ObjectRef<T> {}
+unsafe impl<T: IntoGEMObject> Sync for ObjectRef<T> {}
+
+impl<T: IntoGEMObject> Clone for ObjectRef<T> {
+    fn clone(&self) -> Self {
+        self.reference()
+    }
+}
+
+impl<T: IntoGEMObject> Drop for ObjectRef<T> {
+    fn drop(&mut self) {
+        // SAFETY: Having an ObjectRef implies holding a GEM reference.
+        // The free callback will take care of deallocation.
+        unsafe {
+            bindings::drm_gem_object_put((*self.ptr).gem_obj() as *const _ as
*mut _);
+        }
+    }
+}
+
+impl<T: IntoGEMObject> Deref for ObjectRef<T> {
+    type Target = T;
+
+    fn deref(&self) -> &Self::Target {
+        // SAFETY: The pointer is valid per the invariant
+        unsafe { &*self.ptr }
+    }
+}
+
+/// A unique reference to a base GEM object.
+pub struct UniqueObjectRef<T: IntoGEMObject> {
+    // Invariant: the pointer is valid and initialized, and this ObjectRef owns
the only reference
+    // to it.
+    ptr: *mut T,
+    _p: PhantomPinned,
+}
+
+impl<T: IntoGEMObject> UniqueObjectRef<T> {
+    /// Downgrade this reference to a shared reference.
+    pub fn into_ref(self) -> ObjectRef<T> {
+        let ptr = self.ptr as *const _;
+        core::mem::forget(self);
+
+        ObjectRef { ptr }
+    }
+}
+
+impl<T: IntoGEMObject> Drop for UniqueObjectRef<T> {
+    fn drop(&mut self) {
+        // SAFETY: Having a UniqueObjectRef implies holding a GEM
+        // reference. The free callback will take care of deallocation.
+        unsafe {
+            bindings::drm_gem_object_put((*self.ptr).gem_obj() as *const _ as
*mut _);
+        }
+    }
+}
+
+impl<T: IntoGEMObject> Deref for UniqueObjectRef<T> {
+    type Target = T;
+
+    fn deref(&self) -> &Self::Target {
+        // SAFETY: The pointer is valid per the invariant
+        unsafe { &*self.ptr }
+    }
+}
+
+impl<T: IntoGEMObject> DerefMut for UniqueObjectRef<T> {
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        // SAFETY: The pointer is valid per the invariant
+        unsafe { &mut *self.ptr }
+    }
+}
+
+pub(super) const fn create_fops() -> bindings::file_operations {
+    // SAFETY: As by the type invariant, it is safe to initialize
`bindings::file_operations`
+    // zeroed.
+    let mut fops: bindings::file_operations = unsafe { core::mem::zeroed() };
+
+    fops.owner = core::ptr::null_mut();
+    fops.open = Some(bindings::drm_open);
+    fops.release = Some(bindings::drm_release);
+    fops.unlocked_ioctl = Some(bindings::drm_ioctl);
+    #[cfg(CONFIG_COMPAT)]
+    {
+        fops.compat_ioctl = Some(bindings::drm_compat_ioctl);
+    }
+    fops.poll = Some(bindings::drm_poll);
+    fops.read = Some(bindings::drm_read);
+    fops.llseek = Some(bindings::noop_llseek);
+    fops.mmap = Some(bindings::drm_gem_mmap);
+
+    fops
+}
diff --git a/rust/kernel/drm/mod.rs b/rust/kernel/drm/mod.rs
index a767942d0b52..c44760a1332f 100644
--- a/rust/kernel/drm/mod.rs
+++ b/rust/kernel/drm/mod.rs
@@ -5,4 +5,5 @@
 pub mod device;
 pub mod drv;
 pub mod file;
+pub mod gem;
 pub mod ioctl;
-- 
2.45.1

Danilo Krummrich

2024-Jun-18 23:31 UTC

head link

[PATCH v2 8/8] nova: add initial driver stub

Add the initial driver stub of Nova, a Rust-based GSP-only driver for
Nvidia GPUs. Nova, in the long term, is intended to serve as the
successor of Nouveau for GSP-firmware-based GPUs. [1]

As a stub driver Nova's focus is to make use of the most basic device /
driver infrastructure required to build a DRM driver on the PCI bus and
serve as demonstration example and justification for this
infrastructure.

In further consequence, the idea is to develop Nova continuously
upstream, using those increments to lift further Rust abstractions and
infrastructure upstream.

Link: https://lore.kernel.org/dri-devel/Zfsj0_tb-0-tNrJy at cassiopeiae/T/#u [1]
Signed-off-by: Danilo Krummrich <dakr at redhat.com>
---
 MAINTAINERS                    |  10 ++
 drivers/gpu/drm/Kconfig        |   2 +
 drivers/gpu/drm/Makefile       |   1 +
 drivers/gpu/drm/nova/Kconfig   |  12 +++
 drivers/gpu/drm/nova/Makefile  |   3 +
 drivers/gpu/drm/nova/driver.rs |  85 ++++++++++++++++
 drivers/gpu/drm/nova/file.rs   |  70 +++++++++++++
 drivers/gpu/drm/nova/gem.rs    |  50 ++++++++++
 drivers/gpu/drm/nova/gpu.rs    | 173 +++++++++++++++++++++++++++++++++
 drivers/gpu/drm/nova/nova.rs   |  18 ++++
 include/uapi/drm/nova_drm.h    | 101 +++++++++++++++++++
 rust/uapi/uapi_helper.h        |   1 +
 12 files changed, 526 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/gpu.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 d6c90161c7bf..1f08bdb2d5c2 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -7039,6 +7039,16 @@ T:	git https://gitlab.freedesktop.org/drm/nouveau.git
 F:	drivers/gpu/drm/nouveau/
 F:	include/uapi/drm/nouveau_drm.h
 
+DRM DRIVER (STUB) FOR NVIDIA GSP GPUS [RUST]
+M:	Danilo Krummrich <dakr at redhat.com>
+L:	dri-devel at lists.freedesktop.org
+L:	nouveau at lists.freedesktop.org
+S:	Supported
+C:	irc://irc.oftc.net/nouveau
+T:	git https://gitlab.freedesktop.org/drm/nova.git
+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 026444eeb5c6..4123f0eccff2 100644
--- a/drivers/gpu/drm/Kconfig
+++ b/drivers/gpu/drm/Kconfig
@@ -308,6 +308,8 @@ 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 f9ca4f8fa6c5..cec017f4925a 100644
--- a/drivers/gpu/drm/Makefile
+++ b/drivers/gpu/drm/Makefile
@@ -172,6 +172,7 @@ obj-$(CONFIG_DRM_VMWGFX)+= vmwgfx/
 obj-$(CONFIG_DRM_VGEM)	+= vgem/
 obj-$(CONFIG_DRM_VKMS)	+= vkms/
 obj-$(CONFIG_DRM_NOUVEAU) +=nouveau/
+obj-$(CONFIG_DRM_NOVA_STUB) += nova/
 obj-$(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..3c15593e054b
--- /dev/null
+++ b/drivers/gpu/drm/nova/Kconfig
@@ -0,0 +1,12 @@
+config DRM_NOVA_STUB
+	tristate "Nova GPU driver stub"
+	depends on DRM
+	depends on PCI
+	depends on RUST
+	depends on RUST_FW_LOADER_ABSTRACTIONS
+	default n
+	help
+	  Choose this if you want to build the Nova stub driver for Nvidia
+	  GSP-based GPUs.
+
+	  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..733ac5fb9f4f
--- /dev/null
+++ b/drivers/gpu/drm/nova/Makefile
@@ -0,0 +1,3 @@
+# SPDX-License-Identifier: GPL-2.0
+
+obj-$(CONFIG_DRM_NOVA_STUB) += nova.o
diff --git a/drivers/gpu/drm/nova/driver.rs b/drivers/gpu/drm/nova/driver.rs
new file mode 100644
index 000000000000..69d0efeb125e
--- /dev/null
+++ b/drivers/gpu/drm/nova/driver.rs
@@ -0,0 +1,85 @@
+// SPDX-License-Identifier: GPL-2.0
+
+use kernel::{
+    bindings, c_str, drm,
+    drm::{drv, ioctl},
+    pci,
+    pci::define_pci_id_table,
+    prelude::*,
+    sync::Arc,
+};
+
+use crate::{file::File, gpu::Gpu};
+
+pub(crate) struct NovaDriver;
+
+/// Convienence type alias for the DRM device type for this driver
+pub(crate) type NovaDevice = drm::device::Device<NovaDriver>;
+
+#[allow(dead_code)]
+pub(crate) struct NovaData {
+    pub(crate) gpu: Arc<Gpu>,
+    pub(crate) pdev: pci::Device,
+}
+
+const BAR0_SIZE: usize = 8;
+pub(crate) type Bar0 = pci::Bar<BAR0_SIZE>;
+
+const INFO: drm::drv::DriverInfo = drm::drv::DriverInfo {
+    major: 0,
+    minor: 0,
+    patchlevel: 0,
+    name: c_str!("nova"),
+    desc: c_str!("Nvidia Graphics"),
+    date: c_str!("20240227"),
+};
+
+impl pci::Driver for NovaDriver {
+    type Data = Arc<NovaData>;
+
+    define_pci_id_table! {
+        (),
+        [ (pci::DeviceId::new(bindings::PCI_VENDOR_ID_NVIDIA,
bindings::PCI_ANY_ID as u32), None) ]
+    }
+
+    fn probe(pdev: &mut pci::Device, _id_info:
Option<&Self::IdInfo>) -> Result<Self::Data> {
+        dev_dbg!(pdev.as_ref(), "Probe Nova GPU driver.\n");
+
+        pdev.enable_device_mem()?;
+        pdev.set_master();
+
+        let bar = pdev.iomap_region_sized::<BAR0_SIZE>(0,
c_str!("nova"))?;
+        let data = Arc::new(
+            NovaData {
+                gpu: Gpu::new(pdev, bar)?,
+                pdev: pdev.clone(),
+            },
+            GFP_KERNEL,
+        )?;
+
+        let drm = drm::device::Device::<NovaDriver>::new(pdev.as_ref(),
data.clone())?;
+        drm::drv::Registration::new_foreign_owned(drm, 0)?;
+
+        Ok(data)
+    }
+
+    fn remove(data: &Self::Data) {
+        dev_dbg!(data.pdev.as_ref(), "Remove Nova GPU driver.\n");
+    }
+}
+
+#[vtable]
+impl drm::drv::Driver for NovaDriver {
+    type Data = Arc<NovaData>;
+    type File = File;
+    type Object = crate::gem::Object;
+
+    const INFO: drm::drv::DriverInfo = INFO;
+    const FEATURES: u32 = drv::FEAT_GEM;
+
+    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..4fa9df536f78
--- /dev/null
+++ b/drivers/gpu/drm/nova/file.rs
@@ -0,0 +1,70 @@
+// SPDX-License-Identifier: GPL-2.0
+
+use crate::driver::{NovaDevice, NovaDriver};
+use crate::gem;
+use kernel::{
+    alloc::flags::*,
+    drm::{self, device::Device as DrmDevice, gem::BaseObject},
+    prelude::*,
+    uapi,
+};
+
+pub(crate) struct File();
+
+/// Convenience type alias for our DRM `File` type
+pub(crate) type DrmFile = drm::file::File<File>;
+
+impl drm::file::DriverFile for File {
+    type Driver = NovaDriver;
+
+    fn open(dev: &DrmDevice<Self::Driver>) ->
Result<Pin<Box<Self>>> {
+        dev_dbg!(dev.as_ref(), "drm::device::Device::open\n");
+
+        Ok(Box::into_pin(Box::new(Self(), GFP_KERNEL)?))
+    }
+}
+
+impl File {
+    /// IOCTL: get_param: Query GPU / driver metadata.
+    pub(crate) fn get_param(
+        dev: &NovaDevice,
+        getparam: &mut uapi::drm_nova_getparam,
+        _file: &DrmFile,
+    ) -> Result<u32> {
+        let pdev = &dev.data().pdev;
+
+        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: &DrmFile,
+    ) -> Result<u32> {
+        let obj = gem::object_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: &DrmFile,
+    ) -> Result<u32> {
+        let bo = gem::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..51bc30c226e2
--- /dev/null
+++ b/drivers/gpu/drm/nova/gem.rs
@@ -0,0 +1,50 @@
+// SPDX-License-Identifier: GPL-2.0
+
+use kernel::{
+    drm::{
+        gem,
+        gem::{BaseObject, ObjectRef},
+    },
+    prelude::*,
+};
+
+use crate::{
+    driver::{NovaDevice, NovaDriver},
+    file::DrmFile,
+};
+
+/// GEM Object inner driver data
+#[pin_data]
+pub(crate) struct DriverObject {}
+
+/// Type alias for the GEM object tyoe for this driver.
+pub(crate) type Object = gem::Object<DriverObject>;
+
+impl gem::BaseDriverObject<Object> for DriverObject {
+    fn new(dev: &NovaDevice, _size: usize) -> impl PinInit<Self,
Error> {
+        dev_dbg!(dev.as_ref(), "DriverObject::new\n");
+        DriverObject {}
+    }
+}
+
+impl gem::DriverObject for DriverObject {
+    type Driver = NovaDriver;
+}
+
+/// Create a new DRM GEM object.
+pub(crate) fn object_new(dev: &NovaDevice, size: usize) ->
Result<ObjectRef<Object>> {
+    let aligned_size = size.next_multiple_of(1 << 12);
+
+    if size == 0 || size > aligned_size {
+        return Err(EINVAL);
+    }
+
+    let gem = Object::new(dev, aligned_size)?;
+
+    Ok(ObjectRef::from_pinned_unique(gem))
+}
+
+/// Look up a GEM object handle for a `File` and return an `ObjectRef` for it.
+pub(crate) fn lookup_handle(file: &DrmFile, handle: u32) ->
Result<ObjectRef<Object>> {
+    Object::lookup_handle(file, handle)
+}
diff --git a/drivers/gpu/drm/nova/gpu.rs b/drivers/gpu/drm/nova/gpu.rs
new file mode 100644
index 000000000000..d2cc45b6b636
--- /dev/null
+++ b/drivers/gpu/drm/nova/gpu.rs
@@ -0,0 +1,173 @@
+// SPDX-License-Identifier: GPL-2.0
+
+use kernel::{
+    device, devres::Devres, error::code::*, firmware, fmt, pci, prelude::*,
str::CString, sync::Arc,
+};
+
+use crate::driver::Bar0;
+use core::fmt::Debug;
+
+/// Enum representing the GPU chipset.
+#[derive(Debug)]
+pub(crate) enum Chipset {
+    TU102 = 0x162,
+    TU104 = 0x164,
+    TU106 = 0x166,
+    TU117 = 0x167,
+    TU116 = 0x168,
+    GA102 = 0x172,
+    GA103 = 0x173,
+    GA104 = 0x174,
+    GA106 = 0x176,
+    GA107 = 0x177,
+    AD102 = 0x192,
+    AD103 = 0x193,
+    AD104 = 0x194,
+    AD106 = 0x196,
+    AD107 = 0x197,
+}
+
+/// Enum representing the GPU generation.
+#[derive(Debug)]
+pub(crate) enum CardType {
+    /// Turing
+    TU100 = 0x160,
+    /// Ampere
+    GA100 = 0x170,
+    /// Ada Lovelace
+    AD100 = 0x190,
+}
+
+/// Structure holding the metadata of the GPU.
+#[allow(dead_code)]
+pub(crate) struct GpuSpec {
+    /// Contents of the boot0 register.
+    boot0: u64,
+    card_type: CardType,
+    chipset: Chipset,
+    /// The revision of the chipset.
+    chiprev: u8,
+}
+
+/// Structure encapsulating the firmware blobs required for the GPU to operate.
+#[allow(dead_code)]
+pub(crate) struct Firmware {
+    booter_load: firmware::Firmware,
+    booter_unload: firmware::Firmware,
+    gsp: firmware::Firmware,
+}
+
+/// Structure holding the resources required to operate the GPU.
+#[allow(dead_code)]
+#[pin_data]
+pub(crate) struct Gpu {
+    spec: GpuSpec,
+    /// MMIO mapping of PCI BAR 0
+    bar: Devres<Bar0>,
+    fw: Firmware,
+}
+
+// TODO replace with something like derive(FromPrimitive)
+impl Chipset {
+    fn from_u32(value: u32) -> Option<Chipset> {
+        match value {
+            0x162 => Some(Chipset::TU102),
+            0x164 => Some(Chipset::TU104),
+            0x166 => Some(Chipset::TU106),
+            0x167 => Some(Chipset::TU117),
+            0x168 => Some(Chipset::TU116),
+            0x172 => Some(Chipset::GA102),
+            0x173 => Some(Chipset::GA103),
+            0x174 => Some(Chipset::GA104),
+            0x176 => Some(Chipset::GA106),
+            0x177 => Some(Chipset::GA107),
+            0x192 => Some(Chipset::AD102),
+            0x193 => Some(Chipset::AD103),
+            0x194 => Some(Chipset::AD104),
+            0x196 => Some(Chipset::AD106),
+            0x197 => Some(Chipset::AD107),
+            _ => None,
+        }
+    }
+}
+
+// TODO replace with something like derive(FromPrimitive)
+impl CardType {
+    fn from_u32(value: u32) -> Option<CardType> {
+        match value {
+            0x160 => Some(CardType::TU100),
+            0x170 => Some(CardType::GA100),
+            0x190 => Some(CardType::AD100),
+            _ => None,
+        }
+    }
+}
+
+impl GpuSpec {
+    fn new(bar: &Devres<Bar0>) -> Result<GpuSpec> {
+        let bar = bar.try_access().ok_or(ENXIO)?;
+        let boot0 = u64::from_le(bar.readq(0));
+        let chip = ((boot0 & 0x1ff00000) >> 20) as u32;
+
+        if boot0 & 0x1f000000 == 0 {
+            return Err(ENODEV);
+        }
+
+        let chipset = match Chipset::from_u32(chip) {
+            Some(x) => x,
+            None => return Err(ENODEV),
+        };
+
+        let card_type = match CardType::from_u32(chip & 0x1f0) {
+            Some(x) => x,
+            None => return Err(ENODEV),
+        };
+
+        Ok(Self {
+            boot0,
+            card_type,
+            chipset,
+            chiprev: (boot0 & 0xff) as u8,
+        })
+    }
+}
+
+impl Firmware {
+    fn new(dev: &device::Device, spec: &GpuSpec, ver: &str) ->
Result<Firmware> {
+        let mut chip_name = CString::try_from_fmt(fmt!("{:?}",
spec.chipset))?;
+        chip_name.make_ascii_lowercase();
+
+        let fw_booter_load_path +           
CString::try_from_fmt(fmt!("nvidia/{}/gsp/booter_load-{}.bin",
&*chip_name, ver,))?;
+        let fw_booter_unload_path +           
CString::try_from_fmt(fmt!("nvidia/{}/gsp/booter_unload-{}.bin",
&*chip_name, ver))?;
+        let fw_gsp_path +           
CString::try_from_fmt(fmt!("nvidia/{}/gsp/gsp-{}.bin",
&*chip_name, ver))?;
+
+        let booter_load = firmware::Firmware::request(&fw_booter_load_path,
dev)?;
+        let booter_unload =
firmware::Firmware::request(&fw_booter_unload_path, dev)?;
+        let gsp = firmware::Firmware::request(&fw_gsp_path, dev)?;
+
+        Ok(Firmware {
+            booter_load,
+            booter_unload,
+            gsp,
+        })
+    }
+}
+
+impl Gpu {
+    pub(crate) fn new(pdev: &pci::Device, bar: Devres<Bar0>) ->
Result<Arc<Gpu>> {
+        let spec = GpuSpec::new(&bar)?;
+        let fw = Firmware::new(pdev.as_ref(), &spec,
"535.113.01")?;
+
+        dev_info!(
+            pdev.as_ref(),
+            "NVIDIA {:?} ({:#x})",
+            spec.chipset,
+            spec.boot0
+        );
+
+        Arc::pin_init(try_pin_init!(Self { spec, bar, fw }), GFP_KERNEL)
+    }
+}
diff --git a/drivers/gpu/drm/nova/nova.rs b/drivers/gpu/drm/nova/nova.rs
new file mode 100644
index 000000000000..c675be404d9b
--- /dev/null
+++ b/drivers/gpu/drm/nova/nova.rs
@@ -0,0 +1,18 @@
+// SPDX-License-Identifier: GPL-2.0
+
+//! Nova GPU Driver
+
+mod driver;
+mod file;
+mod gem;
+mod gpu;
+
+use crate::driver::NovaDriver;
+
+kernel::module_pci_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 ed42a456da2e..b9ab3406b2ce 100644
--- a/rust/uapi/uapi_helper.h
+++ b/rust/uapi/uapi_helper.h
@@ -8,5 +8,6 @@
 
 #include <uapi/asm-generic/ioctl.h>
 #include <uapi/drm/drm.h>
+#include <uapi/drm/nova_drm.h>
 #include <uapi/linux/mii.h>
 #include <uapi/linux/ethtool.h>
-- 
2.45.1

Danilo Krummrich

2024-Jun-18 23:31 UTC

head link

[PATCH v2 10/10] nova: add initial driver stub

Add the initial driver stub of Nova, a Rust-based GSP-only driver for
Nvidia GPUs. Nova, in the long term, is intended to serve as the
successor of Nouveau for GSP-firmware-based GPUs. [1]

As a stub driver Nova's focus is to make use of the most basic device /
driver infrastructure required to build a DRM driver on the PCI bus and
serve as demonstration example and justification for this
infrastructure.

In further consequence, the idea is to develop Nova continuously
upstream, using those increments to lift further Rust abstractions and
infrastructure upstream.

Link: https://lore.kernel.org/dri-devel/Zfsj0_tb-0-tNrJy at cassiopeiae/T/#u [1]
Signed-off-by: Danilo Krummrich <dakr at redhat.com>
---
 MAINTAINERS                    |  10 ++
 drivers/gpu/drm/Kconfig        |   2 +
 drivers/gpu/drm/Makefile       |   1 +
 drivers/gpu/drm/nova/Kconfig   |  12 +++
 drivers/gpu/drm/nova/Makefile  |   3 +
 drivers/gpu/drm/nova/driver.rs |  85 ++++++++++++++++
 drivers/gpu/drm/nova/file.rs   |  70 +++++++++++++
 drivers/gpu/drm/nova/gem.rs    |  50 ++++++++++
 drivers/gpu/drm/nova/gpu.rs    | 173 +++++++++++++++++++++++++++++++++
 drivers/gpu/drm/nova/nova.rs   |  18 ++++
 include/uapi/drm/nova_drm.h    | 101 +++++++++++++++++++
 rust/uapi/uapi_helper.h        |   1 +
 12 files changed, 526 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/gpu.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 d6c90161c7bf..1f08bdb2d5c2 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -7039,6 +7039,16 @@ T:	git https://gitlab.freedesktop.org/drm/nouveau.git
 F:	drivers/gpu/drm/nouveau/
 F:	include/uapi/drm/nouveau_drm.h
 
+DRM DRIVER (STUB) FOR NVIDIA GSP GPUS [RUST]
+M:	Danilo Krummrich <dakr at redhat.com>
+L:	dri-devel at lists.freedesktop.org
+L:	nouveau at lists.freedesktop.org
+S:	Supported
+C:	irc://irc.oftc.net/nouveau
+T:	git https://gitlab.freedesktop.org/drm/nova.git
+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 026444eeb5c6..4123f0eccff2 100644
--- a/drivers/gpu/drm/Kconfig
+++ b/drivers/gpu/drm/Kconfig
@@ -308,6 +308,8 @@ 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 f9ca4f8fa6c5..cec017f4925a 100644
--- a/drivers/gpu/drm/Makefile
+++ b/drivers/gpu/drm/Makefile
@@ -172,6 +172,7 @@ obj-$(CONFIG_DRM_VMWGFX)+= vmwgfx/
 obj-$(CONFIG_DRM_VGEM)	+= vgem/
 obj-$(CONFIG_DRM_VKMS)	+= vkms/
 obj-$(CONFIG_DRM_NOUVEAU) +=nouveau/
+obj-$(CONFIG_DRM_NOVA_STUB) += nova/
 obj-$(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..3c15593e054b
--- /dev/null
+++ b/drivers/gpu/drm/nova/Kconfig
@@ -0,0 +1,12 @@
+config DRM_NOVA_STUB
+	tristate "Nova GPU driver stub"
+	depends on DRM
+	depends on PCI
+	depends on RUST
+	depends on RUST_FW_LOADER_ABSTRACTIONS
+	default n
+	help
+	  Choose this if you want to build the Nova stub driver for Nvidia
+	  GSP-based GPUs.
+
+	  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..733ac5fb9f4f
--- /dev/null
+++ b/drivers/gpu/drm/nova/Makefile
@@ -0,0 +1,3 @@
+# SPDX-License-Identifier: GPL-2.0
+
+obj-$(CONFIG_DRM_NOVA_STUB) += nova.o
diff --git a/drivers/gpu/drm/nova/driver.rs b/drivers/gpu/drm/nova/driver.rs
new file mode 100644
index 000000000000..69d0efeb125e
--- /dev/null
+++ b/drivers/gpu/drm/nova/driver.rs
@@ -0,0 +1,85 @@
+// SPDX-License-Identifier: GPL-2.0
+
+use kernel::{
+    bindings, c_str, drm,
+    drm::{drv, ioctl},
+    pci,
+    pci::define_pci_id_table,
+    prelude::*,
+    sync::Arc,
+};
+
+use crate::{file::File, gpu::Gpu};
+
+pub(crate) struct NovaDriver;
+
+/// Convienence type alias for the DRM device type for this driver
+pub(crate) type NovaDevice = drm::device::Device<NovaDriver>;
+
+#[allow(dead_code)]
+pub(crate) struct NovaData {
+    pub(crate) gpu: Arc<Gpu>,
+    pub(crate) pdev: pci::Device,
+}
+
+const BAR0_SIZE: usize = 8;
+pub(crate) type Bar0 = pci::Bar<BAR0_SIZE>;
+
+const INFO: drm::drv::DriverInfo = drm::drv::DriverInfo {
+    major: 0,
+    minor: 0,
+    patchlevel: 0,
+    name: c_str!("nova"),
+    desc: c_str!("Nvidia Graphics"),
+    date: c_str!("20240227"),
+};
+
+impl pci::Driver for NovaDriver {
+    type Data = Arc<NovaData>;
+
+    define_pci_id_table! {
+        (),
+        [ (pci::DeviceId::new(bindings::PCI_VENDOR_ID_NVIDIA,
bindings::PCI_ANY_ID as u32), None) ]
+    }
+
+    fn probe(pdev: &mut pci::Device, _id_info:
Option<&Self::IdInfo>) -> Result<Self::Data> {
+        dev_dbg!(pdev.as_ref(), "Probe Nova GPU driver.\n");
+
+        pdev.enable_device_mem()?;
+        pdev.set_master();
+
+        let bar = pdev.iomap_region_sized::<BAR0_SIZE>(0,
c_str!("nova"))?;
+        let data = Arc::new(
+            NovaData {
+                gpu: Gpu::new(pdev, bar)?,
+                pdev: pdev.clone(),
+            },
+            GFP_KERNEL,
+        )?;
+
+        let drm = drm::device::Device::<NovaDriver>::new(pdev.as_ref(),
data.clone())?;
+        drm::drv::Registration::new_foreign_owned(drm, 0)?;
+
+        Ok(data)
+    }
+
+    fn remove(data: &Self::Data) {
+        dev_dbg!(data.pdev.as_ref(), "Remove Nova GPU driver.\n");
+    }
+}
+
+#[vtable]
+impl drm::drv::Driver for NovaDriver {
+    type Data = Arc<NovaData>;
+    type File = File;
+    type Object = crate::gem::Object;
+
+    const INFO: drm::drv::DriverInfo = INFO;
+    const FEATURES: u32 = drv::FEAT_GEM;
+
+    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..4fa9df536f78
--- /dev/null
+++ b/drivers/gpu/drm/nova/file.rs
@@ -0,0 +1,70 @@
+// SPDX-License-Identifier: GPL-2.0
+
+use crate::driver::{NovaDevice, NovaDriver};
+use crate::gem;
+use kernel::{
+    alloc::flags::*,
+    drm::{self, device::Device as DrmDevice, gem::BaseObject},
+    prelude::*,
+    uapi,
+};
+
+pub(crate) struct File();
+
+/// Convenience type alias for our DRM `File` type
+pub(crate) type DrmFile = drm::file::File<File>;
+
+impl drm::file::DriverFile for File {
+    type Driver = NovaDriver;
+
+    fn open(dev: &DrmDevice<Self::Driver>) ->
Result<Pin<Box<Self>>> {
+        dev_dbg!(dev.as_ref(), "drm::device::Device::open\n");
+
+        Ok(Box::into_pin(Box::new(Self(), GFP_KERNEL)?))
+    }
+}
+
+impl File {
+    /// IOCTL: get_param: Query GPU / driver metadata.
+    pub(crate) fn get_param(
+        dev: &NovaDevice,
+        getparam: &mut uapi::drm_nova_getparam,
+        _file: &DrmFile,
+    ) -> Result<u32> {
+        let pdev = &dev.data().pdev;
+
+        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: &DrmFile,
+    ) -> Result<u32> {
+        let obj = gem::object_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: &DrmFile,
+    ) -> Result<u32> {
+        let bo = gem::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..51bc30c226e2
--- /dev/null
+++ b/drivers/gpu/drm/nova/gem.rs
@@ -0,0 +1,50 @@
+// SPDX-License-Identifier: GPL-2.0
+
+use kernel::{
+    drm::{
+        gem,
+        gem::{BaseObject, ObjectRef},
+    },
+    prelude::*,
+};
+
+use crate::{
+    driver::{NovaDevice, NovaDriver},
+    file::DrmFile,
+};
+
+/// GEM Object inner driver data
+#[pin_data]
+pub(crate) struct DriverObject {}
+
+/// Type alias for the GEM object tyoe for this driver.
+pub(crate) type Object = gem::Object<DriverObject>;
+
+impl gem::BaseDriverObject<Object> for DriverObject {
+    fn new(dev: &NovaDevice, _size: usize) -> impl PinInit<Self,
Error> {
+        dev_dbg!(dev.as_ref(), "DriverObject::new\n");
+        DriverObject {}
+    }
+}
+
+impl gem::DriverObject for DriverObject {
+    type Driver = NovaDriver;
+}
+
+/// Create a new DRM GEM object.
+pub(crate) fn object_new(dev: &NovaDevice, size: usize) ->
Result<ObjectRef<Object>> {
+    let aligned_size = size.next_multiple_of(1 << 12);
+
+    if size == 0 || size > aligned_size {
+        return Err(EINVAL);
+    }
+
+    let gem = Object::new(dev, aligned_size)?;
+
+    Ok(ObjectRef::from_pinned_unique(gem))
+}
+
+/// Look up a GEM object handle for a `File` and return an `ObjectRef` for it.
+pub(crate) fn lookup_handle(file: &DrmFile, handle: u32) ->
Result<ObjectRef<Object>> {
+    Object::lookup_handle(file, handle)
+}
diff --git a/drivers/gpu/drm/nova/gpu.rs b/drivers/gpu/drm/nova/gpu.rs
new file mode 100644
index 000000000000..d2cc45b6b636
--- /dev/null
+++ b/drivers/gpu/drm/nova/gpu.rs
@@ -0,0 +1,173 @@
+// SPDX-License-Identifier: GPL-2.0
+
+use kernel::{
+    device, devres::Devres, error::code::*, firmware, fmt, pci, prelude::*,
str::CString, sync::Arc,
+};
+
+use crate::driver::Bar0;
+use core::fmt::Debug;
+
+/// Enum representing the GPU chipset.
+#[derive(Debug)]
+pub(crate) enum Chipset {
+    TU102 = 0x162,
+    TU104 = 0x164,
+    TU106 = 0x166,
+    TU117 = 0x167,
+    TU116 = 0x168,
+    GA102 = 0x172,
+    GA103 = 0x173,
+    GA104 = 0x174,
+    GA106 = 0x176,
+    GA107 = 0x177,
+    AD102 = 0x192,
+    AD103 = 0x193,
+    AD104 = 0x194,
+    AD106 = 0x196,
+    AD107 = 0x197,
+}
+
+/// Enum representing the GPU generation.
+#[derive(Debug)]
+pub(crate) enum CardType {
+    /// Turing
+    TU100 = 0x160,
+    /// Ampere
+    GA100 = 0x170,
+    /// Ada Lovelace
+    AD100 = 0x190,
+}
+
+/// Structure holding the metadata of the GPU.
+#[allow(dead_code)]
+pub(crate) struct GpuSpec {
+    /// Contents of the boot0 register.
+    boot0: u64,
+    card_type: CardType,
+    chipset: Chipset,
+    /// The revision of the chipset.
+    chiprev: u8,
+}
+
+/// Structure encapsulating the firmware blobs required for the GPU to operate.
+#[allow(dead_code)]
+pub(crate) struct Firmware {
+    booter_load: firmware::Firmware,
+    booter_unload: firmware::Firmware,
+    gsp: firmware::Firmware,
+}
+
+/// Structure holding the resources required to operate the GPU.
+#[allow(dead_code)]
+#[pin_data]
+pub(crate) struct Gpu {
+    spec: GpuSpec,
+    /// MMIO mapping of PCI BAR 0
+    bar: Devres<Bar0>,
+    fw: Firmware,
+}
+
+// TODO replace with something like derive(FromPrimitive)
+impl Chipset {
+    fn from_u32(value: u32) -> Option<Chipset> {
+        match value {
+            0x162 => Some(Chipset::TU102),
+            0x164 => Some(Chipset::TU104),
+            0x166 => Some(Chipset::TU106),
+            0x167 => Some(Chipset::TU117),
+            0x168 => Some(Chipset::TU116),
+            0x172 => Some(Chipset::GA102),
+            0x173 => Some(Chipset::GA103),
+            0x174 => Some(Chipset::GA104),
+            0x176 => Some(Chipset::GA106),
+            0x177 => Some(Chipset::GA107),
+            0x192 => Some(Chipset::AD102),
+            0x193 => Some(Chipset::AD103),
+            0x194 => Some(Chipset::AD104),
+            0x196 => Some(Chipset::AD106),
+            0x197 => Some(Chipset::AD107),
+            _ => None,
+        }
+    }
+}
+
+// TODO replace with something like derive(FromPrimitive)
+impl CardType {
+    fn from_u32(value: u32) -> Option<CardType> {
+        match value {
+            0x160 => Some(CardType::TU100),
+            0x170 => Some(CardType::GA100),
+            0x190 => Some(CardType::AD100),
+            _ => None,
+        }
+    }
+}
+
+impl GpuSpec {
+    fn new(bar: &Devres<Bar0>) -> Result<GpuSpec> {
+        let bar = bar.try_access().ok_or(ENXIO)?;
+        let boot0 = u64::from_le(bar.readq(0));
+        let chip = ((boot0 & 0x1ff00000) >> 20) as u32;
+
+        if boot0 & 0x1f000000 == 0 {
+            return Err(ENODEV);
+        }
+
+        let chipset = match Chipset::from_u32(chip) {
+            Some(x) => x,
+            None => return Err(ENODEV),
+        };
+
+        let card_type = match CardType::from_u32(chip & 0x1f0) {
+            Some(x) => x,
+            None => return Err(ENODEV),
+        };
+
+        Ok(Self {
+            boot0,
+            card_type,
+            chipset,
+            chiprev: (boot0 & 0xff) as u8,
+        })
+    }
+}
+
+impl Firmware {
+    fn new(dev: &device::Device, spec: &GpuSpec, ver: &str) ->
Result<Firmware> {
+        let mut chip_name = CString::try_from_fmt(fmt!("{:?}",
spec.chipset))?;
+        chip_name.make_ascii_lowercase();
+
+        let fw_booter_load_path +           
CString::try_from_fmt(fmt!("nvidia/{}/gsp/booter_load-{}.bin",
&*chip_name, ver,))?;
+        let fw_booter_unload_path +           
CString::try_from_fmt(fmt!("nvidia/{}/gsp/booter_unload-{}.bin",
&*chip_name, ver))?;
+        let fw_gsp_path +           
CString::try_from_fmt(fmt!("nvidia/{}/gsp/gsp-{}.bin",
&*chip_name, ver))?;
+
+        let booter_load = firmware::Firmware::request(&fw_booter_load_path,
dev)?;
+        let booter_unload =
firmware::Firmware::request(&fw_booter_unload_path, dev)?;
+        let gsp = firmware::Firmware::request(&fw_gsp_path, dev)?;
+
+        Ok(Firmware {
+            booter_load,
+            booter_unload,
+            gsp,
+        })
+    }
+}
+
+impl Gpu {
+    pub(crate) fn new(pdev: &pci::Device, bar: Devres<Bar0>) ->
Result<Arc<Gpu>> {
+        let spec = GpuSpec::new(&bar)?;
+        let fw = Firmware::new(pdev.as_ref(), &spec,
"535.113.01")?;
+
+        dev_info!(
+            pdev.as_ref(),
+            "NVIDIA {:?} ({:#x})",
+            spec.chipset,
+            spec.boot0
+        );
+
+        Arc::pin_init(try_pin_init!(Self { spec, bar, fw }), GFP_KERNEL)
+    }
+}
diff --git a/drivers/gpu/drm/nova/nova.rs b/drivers/gpu/drm/nova/nova.rs
new file mode 100644
index 000000000000..c675be404d9b
--- /dev/null
+++ b/drivers/gpu/drm/nova/nova.rs
@@ -0,0 +1,18 @@
+// SPDX-License-Identifier: GPL-2.0
+
+//! Nova GPU Driver
+
+mod driver;
+mod file;
+mod gem;
+mod gpu;
+
+use crate::driver::NovaDriver;
+
+kernel::module_pci_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 ed42a456da2e..b9ab3406b2ce 100644
--- a/rust/uapi/uapi_helper.h
+++ b/rust/uapi/uapi_helper.h
@@ -8,5 +8,6 @@
 
 #include <uapi/asm-generic/ioctl.h>
 #include <uapi/drm/drm.h>
+#include <uapi/drm/nova_drm.h>
 #include <uapi/linux/mii.h>
 #include <uapi/linux/ethtool.h>
-- 
2.45.1

Danilo Krummrich

2024-Jun-18 23:42 UTC

head link

Device / Driver and PCI Rust abstractions

https://lore.kernel.org/lkml/20240618234025.15036-1-dakr at redhat.com/

Daniel Vetter

2024-Sep-02 16:40 UTC

head link

[PATCH v2 0/8] DRM Rust abstractions and Nova

On Wed, Jun 19, 2024 at 01:31:36AM +0200, Danilo Krummrich
wrote:> This patch series implements some basic DRM Rust abstractions and a stub
> implementation of the Nova GPU driver.
> 
> Nova is intended to be developed upstream, starting out with just a stub
driver
> to lift some initial required infrastructure upstream. A more detailed
> explanation can be found in [1].
> 
> This patch series is based on the "Device / Driver and PCI Rust
abstractions"
> series [2].
> 
> The DRM bits can also be found in [3] and the Nova bits in [4].
> 
> Changes in v2:
> =============> - split up the DRM device / driver abstractions in three
separate commits
> - separate `struct drm_device` abstraction in a separte source file more
>   cleanly
> - switch `struct drm_driver` and `struct file_operations` to 'static
const'
>   allocations
> - implement `Registration::new_foreign_owned` (using `Devres`), such that
we
>   don't need to keep the `Registration` alive on the Rust side, but
>   automatically revoke it on device unbind
> - add missing DRM driver features (Rob)
> - use `module_pci_driver!` macro in Nova
> - use a const sized `pci::Bar` in Nova
> - increase the total amount of Documentation, rephrase some safety comments
and
>   commit messages for less ambiguity
> - fix compilation issues with some documentation example
> 
> [1] https://lore.kernel.org/dri-devel/Zfsj0_tb-0-tNrJy at cassiopeiae/T/#u
> [2] Reply to this mail titled "Device / Driver and PCI Rust
abstractions".
> [3] https://gitlab.freedesktop.org/drm/misc/kernel/-/tree/topic/rust-drm
> [4] https://gitlab.freedesktop.org/drm/nova/-/tree/nova-next
Ok finally stopped dragging my feet on this, went through my old comments,
looked at stuff again, and wrote some replies.

I think all but the question around type safety for drm_driver->features
can be sorted out post-merge, when we have a driver that needs it. The
feature flags stuff I think essentially makes the current abstraction
unsafe, and you can blow up when constructing a new drm::Device instance
if you're creative enough I think.

Cheers, Sima
> 
> Asahi Lina (4):
>   rust: drm: ioctl: Add DRM ioctl abstraction
>   rust: Add a Sealed trait
>   rust: drm: file: Add File abstraction
>   rust: drm: gem: Add GEM object abstraction
> 
> Danilo Krummrich (4):
>   rust: drm: add driver abstractions
>   rust: drm: add device abstraction
>   rust: drm: add DRM driver registration
>   nova: add initial driver stub
> 
>  MAINTAINERS                     |  10 +
>  drivers/gpu/drm/Kconfig         |   2 +
>  drivers/gpu/drm/Makefile        |   1 +
>  drivers/gpu/drm/nova/Kconfig    |  12 +
>  drivers/gpu/drm/nova/Makefile   |   3 +
>  drivers/gpu/drm/nova/driver.rs  |  85 +++++++
>  drivers/gpu/drm/nova/file.rs    |  70 ++++++
>  drivers/gpu/drm/nova/gem.rs     |  50 ++++
>  drivers/gpu/drm/nova/gpu.rs     | 173 ++++++++++++++
>  drivers/gpu/drm/nova/nova.rs    |  18 ++
>  include/uapi/drm/nova_drm.h     | 101 ++++++++
>  rust/bindings/bindings_helper.h |   5 +
>  rust/helpers.c                  |  23 ++
>  rust/kernel/drm/device.rs       | 182 ++++++++++++++
>  rust/kernel/drm/drv.rs          | 199 ++++++++++++++++
>  rust/kernel/drm/file.rs         | 116 +++++++++
>  rust/kernel/drm/gem/mod.rs      | 409 ++++++++++++++++++++++++++++++++
>  rust/kernel/drm/ioctl.rs        | 153 ++++++++++++
>  rust/kernel/drm/mod.rs          |   9 +
>  rust/kernel/lib.rs              |   7 +
>  rust/uapi/uapi_helper.h         |   2 +
>  21 files changed, 1630 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/gpu.rs
>  create mode 100644 drivers/gpu/drm/nova/nova.rs
>  create mode 100644 include/uapi/drm/nova_drm.h
>  create mode 100644 rust/kernel/drm/device.rs
>  create mode 100644 rust/kernel/drm/drv.rs
>  create mode 100644 rust/kernel/drm/file.rs
>  create mode 100644 rust/kernel/drm/gem/mod.rs
>  create mode 100644 rust/kernel/drm/ioctl.rs
>  create mode 100644 rust/kernel/drm/mod.rs
> 
> 
> base-commit: 6646240d29b11de3177f71ff777d0ae683c32623
> -- 
> 2.45.1
> 
-- 
Simona Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch

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