[PATCH v4 0/6] Initial Nova Core series

[PATCH v4 0/6] Initial Nova Core series

[Danilo Krummrich]

This is the initial series for the nova-core stub driver.

nova-core is intended to serve as a common base for nova-drm (the
corresponding DRM driver) and the vGPU manager VFIO driver, serving as a
hard- and firmware abstraction layer for GSP-based NVIDIA GPUs.

The Nova project, including nova-core and nova-drm, in the long term,
is intended to serve as the successor of Nouveau for all GSP-based GPUs.

The motivation for both, starting a successor project for Nouveau and
doing so using the Rust programming language, is documented in detail
through a previous post on the mailing list [1], an LWN article [2] and a
talk from LPC '24.

In order to avoid the chicken and egg problem to require a user to
upstream Rust abstractions, but at the same time require the Rust
abstractions to implement the driver, nova-core kicks off as a driver
stub and is subsequently developed upstream.

Besides the driver itself and the corresponding documentation, i.e. guidelines,
task list, etc., this series also carries a few more patches to more flexibly
compose firmware path strings for the .modinfo section.

Link: https://lore.kernel.org/dri-devel/Zfsj0_tb-0-tNrJy@cassiopeiae/T/#u [1]
Link: https://lwn.net/Articles/990736/ [2]
Link: https://youtu.be/3Igmx28B3BQ?si=sBdSEer4tAPKGpOs [3]

Changes in v4:
  - in `regs::Boot0` take a `&Bar0` and let deref coercion do its thing
    (Alexandre)
  - add missing firmware path string to the .modinfo section (Greg)
  - add some infrastructure to compose firmware path strings more flexibly

Changes in v3:
  - impl TryFrom<u32> for Chipset
  - add Chipset::arch()
  - initialize revision from Boot0
  - in Firmware, eliminate repeating code pattern using a closure (thanks to
    Alexandre)
  - use #[expect(dead_code)] for Firmware
  - Replace some Rust specific rules with links to existing R4L documentation.
  - Link in R4L submit checklist.
  - Update task entry "Page abstraction for foreign pages" with Lina's work.

Changes in v2:
  - Fix module name in Kconfig description. (John)
  - Expand Kconfig description a bit. (John)
  - Expand name for PCI BAR0 region.
  - Do not store / print boot0 raw register value. (John)
  - Rename CardType to Architecture, rename enum names to represent the
    architecture name and adjust enum values according to the register
    definition. (John)
  - Add an abstraction for register accesses.
  - Print chipset, architecture and revision.
  - Load bootloader firmware. (Timur)
  - Add task "Generic register abstraction".
  - Change complexity of "Debugfs abstractions".

Danilo Krummrich (6):
  rust: module: add type `LocalModule`
  rust: str: provide const fn as_bytes() for BStr
  rust: firmware: introduce `firmware::ModInfoBuilder`
  rust: firmware: add `module_firmware!` macro
  gpu: nova-core: add initial driver stub
  gpu: nova-core: add initial documentation

 Documentation/gpu/drivers.rst              |   1 +
 Documentation/gpu/nova/core/guidelines.rst |  24 ++
 Documentation/gpu/nova/core/todo.rst       | 446 +++++++++++++++++++++
 Documentation/gpu/nova/guidelines.rst      |  69 ++++
 Documentation/gpu/nova/index.rst           |  30 ++
 MAINTAINERS                                |  11 +
 drivers/gpu/Makefile                       |   1 +
 drivers/gpu/nova-core/Kconfig              |  14 +
 drivers/gpu/nova-core/Makefile             |   3 +
 drivers/gpu/nova-core/driver.rs            |  47 +++
 drivers/gpu/nova-core/firmware.rs          |  45 +++
 drivers/gpu/nova-core/gpu.rs               | 225 +++++++++++
 drivers/gpu/nova-core/nova_core.rs         |  19 +
 drivers/gpu/nova-core/regs.rs              |  55 +++
 drivers/video/Kconfig                      |   1 +
 rust/kernel/firmware.rs                    | 177 ++++++++
 rust/kernel/str.rs                         |   6 +
 rust/macros/module.rs                      |   2 +
 18 files changed, 1176 insertions(+)
 create mode 100644 Documentation/gpu/nova/core/guidelines.rst
 create mode 100644 Documentation/gpu/nova/core/todo.rst
 create mode 100644 Documentation/gpu/nova/guidelines.rst
 create mode 100644 Documentation/gpu/nova/index.rst
 create mode 100644 drivers/gpu/nova-core/Kconfig
 create mode 100644 drivers/gpu/nova-core/Makefile
 create mode 100644 drivers/gpu/nova-core/driver.rs
 create mode 100644 drivers/gpu/nova-core/firmware.rs
 create mode 100644 drivers/gpu/nova-core/gpu.rs
 create mode 100644 drivers/gpu/nova-core/nova_core.rs
 create mode 100644 drivers/gpu/nova-core/regs.rs


base-commit: ac9c34d1e45a4c25174ced4fc0cfc33ff3ed08c7
-- 
2.48.1

[PATCH v4 1/6] rust: module: add type `LocalModule`

[Danilo Krummrich]

The `LocalModule` type is the type of the module created by `module!`,
`module_pci_driver!`, `module_platform_driver!`, etc.

Since the exact type of the module is sometimes generated on the fly by
the listed macros, provide an alias.

This is first used by the `module_firmware!` macro introduced in a
subsequent patch.

Suggested-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
---
 rust/macros/module.rs | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/rust/macros/module.rs b/rust/macros/module.rs
index cdf94f4982df..6ba9210677c5 100644
--- a/rust/macros/module.rs
+++ b/rust/macros/module.rs
@@ -228,6 +228,8 @@ pub(crate) fn module(ts: TokenStream) -> TokenStream {
                 kernel::ThisModule::from_ptr(core::ptr::null_mut())
             }};
 
+            type LocalModule = {type_};
+
             impl kernel::ModuleMetadata for {type_} {{
                 const NAME: &'static kernel::str::CStr = kernel::c_str!(\"{name}\");
             }}
-- 
2.48.1

[PATCH v4 2/6] rust: str: provide const fn as_bytes() for BStr

[Danilo Krummrich]

`BStr` already dereference to `&[u8]` through the `Deref` trait,
however, this can't be called from const context.

Hence, provide a separate const function for this.

This is used in subsequent nova-core patches.

Signed-off-by: Danilo Krummrich <dakr@kernel.org>
---
 rust/kernel/str.rs | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/rust/kernel/str.rs b/rust/kernel/str.rs
index 28e2201604d6..71e8a819016d 100644
--- a/rust/kernel/str.rs
+++ b/rust/kernel/str.rs
@@ -31,6 +31,12 @@ pub const fn from_bytes(bytes: &[u8]) -> &Self {
         // SAFETY: `BStr` is transparent to `[u8]`.
         unsafe { &*(bytes as *const [u8] as *const BStr) }
     }
+
+    /// Same as `self.deref()`, but works in const context.
+    #[inline]
+    pub const fn as_bytes(&self) -> &[u8] {
+        &self.0
+    }
 }
 
 impl fmt::Display for BStr {
-- 
2.48.1

[PATCH v4 3/6] rust: firmware: introduce `firmware::ModInfoBuilder`

[Danilo Krummrich]

The `firmware` field of the `module!` only accepts literal strings,
which is due to the fact that it is implemented as a proc macro.

Some drivers require a lot of firmware files (such as nova-core) and
hence benefit from more flexibility composing firmware path strings.

The `firmware::ModInfoBuilder` is a helper component to flexibly compose
firmware path strings for the .modinfo section in const context.

It is meant to be used in combination with `kernel::module_firmware!`,
which is introduced in a subsequent patch.

Co-developed-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
---
 rust/kernel/firmware.rs | 98 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 98 insertions(+)

diff --git a/rust/kernel/firmware.rs b/rust/kernel/firmware.rs
index c5162fdc95ff..0f27dc212d6e 100644
--- a/rust/kernel/firmware.rs
+++ b/rust/kernel/firmware.rs
@@ -115,3 +115,101 @@ unsafe impl Send for Firmware {}
 // SAFETY: `Firmware` only holds a pointer to a C `struct firmware`, references to which are safe to
 // be used from any thread.
 unsafe impl Sync for Firmware {}
+
+/// Builder for firmware module info.
+///
+/// [`ModInfoBuilder`] is a helper component to flexibly compose firmware paths strings for the
+/// .modinfo section in const context.
+///
+/// It is meant to be used in combination with [`kernel::module_firmware!`].
+///
+/// For more details and an example, see [`kernel::module_firmware!`].
+pub struct ModInfoBuilder<const N: usize> {
+    buf: [u8; N],
+    n: usize,
+    module_name: &'static CStr,
+}
+
+impl<const N: usize> ModInfoBuilder<N> {
+    /// Create an empty builder instance.
+    pub const fn new(module_name: &'static CStr) -> Self {
+        Self {
+            buf: [0; N],
+            n: 0,
+            module_name,
+        }
+    }
+
+    const fn push_internal(mut self, bytes: &[u8]) -> Self {
+        let mut j = 0;
+
+        if N == 0 {
+            self.n += bytes.len();
+            return self;
+        }
+
+        while j < bytes.len() {
+            if self.n < N {
+                self.buf[self.n] = bytes[j];
+            }
+            self.n += 1;
+            j += 1;
+        }
+        self
+    }
+
+    /// Push an additional path component.
+    ///
+    /// After a new [`ModInfoBuilder`] instance has been created, [`ModInfoBuilder::prepare`] must
+    /// be called before adding path components.
+    pub const fn push(self, bytes: &[u8]) -> Self {
+        if N != 0 && self.n == 0 {
+            crate::build_error!("Must call prepare() before push().");
+        }
+
+        self.push_internal(bytes)
+    }
+
+    const fn prepare_module_name(self) -> Self {
+        let mut this = self;
+        let module_name = this.module_name;
+
+        if !this.module_name.is_empty() {
+            this = this.push_internal(module_name.as_bytes_with_nul());
+
+            if N != 0 {
+                // Re-use the space taken by the NULL terminator and swap it with the '.' separator.
+                this.buf[this.n - 1] = b'.';
+            }
+        }
+
+        this.push_internal(b"firmware=")
+    }
+
+    /// Prepare for the next module info entry.
+    ///
+    /// Must be called before [`ModInfoBuilder::push`] can be called.
+    pub const fn prepare(self) -> Self {
+        self.push_internal(b"\0").prepare_module_name()
+    }
+
+    /// Build the byte array.
+    pub const fn build(self) -> [u8; N] {
+        // Add the final NULL terminator.
+        let this = self.push_internal(b"\0");
+
+        if this.n == N {
+            this.buf
+        } else {
+            crate::build_error!("Length mismatch.");
+        }
+    }
+}
+
+impl ModInfoBuilder<0> {
+    /// Return the length of the byte array to build.
+    pub const fn build_length(self) -> usize {
+        // Compensate for the NULL terminator added by `build`.
+        self.n + 1
+    }
+}
-- 
2.48.1

[PATCH v4 4/6] rust: firmware: add `module_firmware!` macro

[Danilo Krummrich]

Analogous to the `module!` macro `module_firmware!` adds additional
firmware path strings to the .modinfo section.

In contrast to `module!`, where path strings need to be string literals,
path strings can be composed with the `firmware::ModInfoBuilder`.

Some drivers require a lot of firmware files (such as nova-core) and
hence benefit from more flexibility composing firmware path strings.

Signed-off-by: Danilo Krummrich <dakr@kernel.org>
---
 rust/kernel/firmware.rs | 79 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 79 insertions(+)

diff --git a/rust/kernel/firmware.rs b/rust/kernel/firmware.rs
index 0f27dc212d6e..5cabbbc9aeb8 100644
--- a/rust/kernel/firmware.rs
+++ b/rust/kernel/firmware.rs
@@ -116,6 +116,85 @@ unsafe impl Send for Firmware {}
 // be used from any thread.
 unsafe impl Sync for Firmware {}
 
+/// Create firmware .modinfo entries.
+///
+/// This macro is the counterpart of the C macro `MODULE_FIRMWARE()`, but instead of taking a
+/// simple string literals, which is already covered by the `firmware` field of
+/// [`crate::prelude::module!`], it allows the caller to pass a builder type (e.g.
+/// [`ModInfoBuilder`]) which can create the firmware modinfo strings in a more flexible way.
+///
+/// Drivers should extend the [`ModInfoBuilder`] with their own driver specific builder type.
+///
+/// The `builder` argument must be a type which implements the following function.
+///
+/// `const fn create(module_name: &'static CStr) -> ModInfoBuilder`
+///
+/// `create` should pass the `module_name` to the [`ModInfoBuilder`] and, with the help of
+/// it construct the corresponding firmware modinfo.
+///
+/// Typically, such contracts would be enforced by a trait, however traits do not (yet) support
+/// const functions.
+///
+/// # Example
+///
+/// ```
+/// # mod module_firmware_test {
+/// # use kernel::firmware;
+/// # use kernel::prelude::*;
+/// #
+/// # struct MyModule;
+/// #
+/// # impl kernel::Module for MyModule {
+/// #     fn init(_module: &'static ThisModule) -> Result<Self> {
+/// #         Ok(Self)
+/// #     }
+/// # }
+/// #
+/// #
+/// struct Builder<const N: usize>;
+///
+/// impl<const N: usize> Builder<N> {
+///     const fn create(module_name: &'static kernel::str::CStr) -> firmware::ModInfoBuilder<N> {
+///         firmware::ModInfoBuilder::new(module_name)
+///             .prepare()
+///             .push(b"vendor/foo.bin")
+///             .prepare()
+///             .push(b"vendor/bar.bin")
+///     }
+/// }
+///
+/// module! {
+///    type: MyModule,
+///    name: "module_firmware_test",
+///    author: "Rust for Linux",
+///    description: "module_firmware! test module",
+///    license: "GPL",
+/// }
+///
+/// kernel::module_firmware!(Builder);
+/// # }
+/// ```
+#[macro_export]
+macro_rules! module_firmware {
+    ($($builder:tt)*) => {
+
+        #[cfg(not(MODULE))]
+        const fn __module_name() -> &'static kernel::str::CStr {
+            <LocalModule as kernel::ModuleMetadata>::NAME
+        }
+
+        #[cfg(MODULE)]
+        const fn __module_name() -> &'static kernel::str::CStr {
+            kernel::c_str!("")
+        }
+
+        #[link_section = ".modinfo"]
+        #[used]
+        static __MODULE_FIRMWARE: [u8; $($builder)*::create(__module_name()).build_length()] =
+            $($builder)*::create(__module_name()).build();
+    };
+}
+
 /// Builder for firmware module info.
 ///
 /// [`ModInfoBuilder`] is a helper component to flexibly compose firmware paths strings for the
-- 
2.48.1

[PATCH v4 5/6] gpu: nova-core: add initial driver stub

[Danilo Krummrich]

Add the initial nova-core driver stub.

nova-core is intended to serve as a common base for nova-drm (the
corresponding DRM driver) and the vGPU manager VFIO driver, serving as a
hard- and firmware abstraction layer for GSP-based NVIDIA GPUs.

The Nova project, including nova-core and nova-drm, in the long term,
is intended to serve as the successor of Nouveau for all GSP-based GPUs.

The motivation for both, starting a successor project for Nouveau and
doing so using the Rust programming language, is documented in detail
through a previous post on the mailing list [1], an LWN article [2] and a
talk from LPC '24.

In order to avoid the chicken and egg problem to require a user to
upstream Rust abstractions, but at the same time require the Rust
abstractions to implement the driver, nova-core kicks off as a driver
stub and is subsequently developed upstream.

Link: https://lore.kernel.org/dri-devel/Zfsj0_tb-0-tNrJy@cassiopeiae/T/#u [1]
Link: https://lwn.net/Articles/990736/ [2]
Link: https://youtu.be/3Igmx28B3BQ?si=sBdSEer4tAPKGpOs [3]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
---
 MAINTAINERS                        |  10 ++
 drivers/gpu/Makefile               |   1 +
 drivers/gpu/nova-core/Kconfig      |  14 ++
 drivers/gpu/nova-core/Makefile     |   3 +
 drivers/gpu/nova-core/driver.rs    |  47 ++++++
 drivers/gpu/nova-core/firmware.rs  |  45 ++++++
 drivers/gpu/nova-core/gpu.rs       | 225 +++++++++++++++++++++++++++++
 drivers/gpu/nova-core/nova_core.rs |  19 +++
 drivers/gpu/nova-core/regs.rs      |  55 +++++++
 drivers/video/Kconfig              |   1 +
 10 files changed, 420 insertions(+)
 create mode 100644 drivers/gpu/nova-core/Kconfig
 create mode 100644 drivers/gpu/nova-core/Makefile
 create mode 100644 drivers/gpu/nova-core/driver.rs
 create mode 100644 drivers/gpu/nova-core/firmware.rs
 create mode 100644 drivers/gpu/nova-core/gpu.rs
 create mode 100644 drivers/gpu/nova-core/nova_core.rs
 create mode 100644 drivers/gpu/nova-core/regs.rs

diff --git a/MAINTAINERS b/MAINTAINERS
index 1b0cc181db74..3c8a3b61af38 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -7438,6 +7438,16 @@ T:	git https://gitlab.freedesktop.org/drm/nouveau.git
 F:	drivers/gpu/drm/nouveau/
 F:	include/uapi/drm/nouveau_drm.h
 
+CORE DRIVER FOR NVIDIA GPUS [RUST]
+M:	Danilo Krummrich <dakr@kernel.org>
+L:	nouveau@lists.freedesktop.org
+S:	Supported
+Q:	https://patchwork.freedesktop.org/project/nouveau/
+B:	https://gitlab.freedesktop.org/drm/nova/-/issues
+C:	irc://irc.oftc.net/nouveau
+T:	git https://gitlab.freedesktop.org/drm/nova.git nova-next
+F:	drivers/gpu/nova-core/
+
 DRM DRIVER FOR OLIMEX LCD-OLINUXINO PANELS
 M:	Stefan Mavrodiev <stefan@olimex.com>
 S:	Maintained
diff --git a/drivers/gpu/Makefile b/drivers/gpu/Makefile
index 8997f0096545..36a54d456630 100644
--- a/drivers/gpu/Makefile
+++ b/drivers/gpu/Makefile
@@ -5,3 +5,4 @@
 obj-y			+= host1x/ drm/ vga/
 obj-$(CONFIG_IMX_IPUV3_CORE)	+= ipu-v3/
 obj-$(CONFIG_TRACE_GPU_MEM)		+= trace/
+obj-$(CONFIG_NOVA_CORE)		+= nova-core/
diff --git a/drivers/gpu/nova-core/Kconfig b/drivers/gpu/nova-core/Kconfig
new file mode 100644
index 000000000000..ad0c06756516
--- /dev/null
+++ b/drivers/gpu/nova-core/Kconfig
@@ -0,0 +1,14 @@
+config NOVA_CORE
+	tristate "Nova Core GPU driver"
+	depends on PCI
+	depends on RUST
+	depends on RUST_FW_LOADER_ABSTRACTIONS
+	default n
+	help
+	  Choose this if you want to build the Nova Core driver for Nvidia
+	  GPUs based on the GPU System Processor (GSP). This is true for Turing
+	  and later GPUs.
+
+	  This driver is work in progress and may not be functional.
+
+	  If M is selected, the module will be called nova_core.
diff --git a/drivers/gpu/nova-core/Makefile b/drivers/gpu/nova-core/Makefile
new file mode 100644
index 000000000000..2d78c50126e1
--- /dev/null
+++ b/drivers/gpu/nova-core/Makefile
@@ -0,0 +1,3 @@
+# SPDX-License-Identifier: GPL-2.0
+
+obj-$(CONFIG_NOVA_CORE) += nova_core.o
diff --git a/drivers/gpu/nova-core/driver.rs b/drivers/gpu/nova-core/driver.rs
new file mode 100644
index 000000000000..63c19f140fbd
--- /dev/null
+++ b/drivers/gpu/nova-core/driver.rs
@@ -0,0 +1,47 @@
+// SPDX-License-Identifier: GPL-2.0
+
+use kernel::{bindings, c_str, pci, prelude::*};
+
+use crate::gpu::Gpu;
+
+#[pin_data]
+pub(crate) struct NovaCore {
+    #[pin]
+    pub(crate) gpu: Gpu,
+}
+
+const BAR0_SIZE: usize = 8;
+pub(crate) type Bar0 = pci::Bar<BAR0_SIZE>;
+
+kernel::pci_device_table!(
+    PCI_TABLE,
+    MODULE_PCI_TABLE,
+    <NovaCore as pci::Driver>::IdInfo,
+    [(
+        pci::DeviceId::from_id(bindings::PCI_VENDOR_ID_NVIDIA, bindings::PCI_ANY_ID as _),
+        ()
+    )]
+);
+
+impl pci::Driver for NovaCore {
+    type IdInfo = ();
+    const ID_TABLE: pci::IdTable<Self::IdInfo> = &PCI_TABLE;
+
+    fn probe(pdev: &mut pci::Device, _info: &Self::IdInfo) -> Result<Pin<KBox<Self>>> {
+        dev_dbg!(pdev.as_ref(), "Probe Nova Core GPU driver.\n");
+
+        pdev.enable_device_mem()?;
+        pdev.set_master();
+
+        let bar = pdev.iomap_region_sized::<BAR0_SIZE>(0, c_str!("nova-core/bar0"))?;
+
+        let this = KBox::pin_init(
+            try_pin_init!(Self {
+                gpu <- Gpu::new(pdev, bar)?,
+            }),
+            GFP_KERNEL,
+        )?;
+
+        Ok(this)
+    }
+}
diff --git a/drivers/gpu/nova-core/firmware.rs b/drivers/gpu/nova-core/firmware.rs
new file mode 100644
index 000000000000..a94caa7cf8d3
--- /dev/null
+++ b/drivers/gpu/nova-core/firmware.rs
@@ -0,0 +1,45 @@
+// SPDX-License-Identifier: GPL-2.0
+
+use crate::gpu;
+use kernel::firmware;
+
+pub(crate) struct ModInfoBuilder<const N: usize>(firmware::ModInfoBuilder<N>);
+
+impl<const N: usize> ModInfoBuilder<N> {
+    const fn make_entry_file(self, chipset: &[u8], fw: &[u8]) -> Self {
+        let version = b"535.113.01";
+
+        ModInfoBuilder(
+            self.0
+                .prepare()
+                .push(b"nvidia/")
+                .push(chipset)
+                .push(b"/gsp/")
+                .push(fw)
+                .push(b"-")
+                .push(version)
+                .push(b".bin"),
+        )
+    }
+
+    const fn make_entry_chipset(self, chipset: &[u8]) -> Self {
+        self.make_entry_file(chipset, b"booter_load")
+            .make_entry_file(chipset, b"booter_unload")
+            .make_entry_file(chipset, b"bootloader")
+            .make_entry_file(chipset, b"gsp")
+    }
+
+    pub(crate) const fn create(
+        module_name: &'static kernel::str::CStr,
+    ) -> firmware::ModInfoBuilder<N> {
+        let mut this = Self(firmware::ModInfoBuilder::new(module_name));
+        let mut i = 0;
+
+        while i < gpu::Chipset::NAMES.len() {
+            this = this.make_entry_chipset(gpu::Chipset::NAMES[i].as_bytes());
+            i += 1;
+        }
+
+        this.0
+    }
+}
diff --git a/drivers/gpu/nova-core/gpu.rs b/drivers/gpu/nova-core/gpu.rs
new file mode 100644
index 000000000000..7693a5df0dc1
--- /dev/null
+++ b/drivers/gpu/nova-core/gpu.rs
@@ -0,0 +1,225 @@
+// SPDX-License-Identifier: GPL-2.0
+
+use kernel::{
+    device, devres::Devres, error::code::*, firmware, fmt, pci, prelude::*, str::BStr, str::CString,
+};
+
+use crate::driver::Bar0;
+use crate::regs;
+use core::fmt;
+
+const fn to_lowercase_bytes<const N: usize>(s: &str) -> [u8; N] {
+    let src = s.as_bytes();
+    let mut dst = [0; N];
+    let mut i = 0;
+
+    while i < src.len() && i < N {
+        dst[i] = (src[i] as char).to_ascii_lowercase() as u8;
+        i += 1;
+    }
+
+    dst
+}
+
+macro_rules! define_chipset {
+    ({ $($variant:ident = $value:expr),* $(,)* }) =>
+    {
+        /// Enum representation of the GPU chipset.
+        #[derive(fmt::Debug)]
+        pub(crate) enum Chipset {
+            $($variant = $value),*,
+        }
+
+        impl Chipset {
+            pub(crate) const ALL: &'static [Chipset] = &[
+                $( Chipset::$variant, )*
+            ];
+
+            pub(crate) const NAMES: [&BStr; Self::ALL.len()] = [
+                $( BStr::from_bytes(
+                        to_lowercase_bytes::<{ stringify!($variant).len() }>(
+                            stringify!($variant)
+                        ).as_slice()
+                ), )*
+            ];
+        }
+    }
+}
+
+define_chipset!({
+    // Turing
+    TU102 = 0x162,
+    TU104 = 0x164,
+    TU106 = 0x166,
+    TU117 = 0x167,
+    TU116 = 0x168,
+    // Ampere
+    GA102 = 0x172,
+    GA103 = 0x173,
+    GA104 = 0x174,
+    GA106 = 0x176,
+    GA107 = 0x177,
+    // Ada
+    AD102 = 0x192,
+    AD103 = 0x193,
+    AD104 = 0x194,
+    AD106 = 0x196,
+    AD107 = 0x197,
+});
+
+impl Chipset {
+    pub(crate) fn arch(&self) -> Architecture {
+        match self {
+            Self::TU102 | Self::TU104 | Self::TU106 | Self::TU117 | Self::TU116 => {
+                Architecture::Turing
+            }
+            Self::GA102 | Self::GA103 | Self::GA104 | Self::GA106 | Self::GA107 => {
+                Architecture::Ampere
+            }
+            Self::AD102 | Self::AD103 | Self::AD104 | Self::AD106 | Self::AD107 => {
+                Architecture::Ada
+            }
+        }
+    }
+}
+
+// TODO
+//
+// The resulting strings are used to generate firmware paths, hence the
+// generated strings have to be stable.
+//
+// Hence, replace with something like strum_macros derive(Display).
+//
+// For now, redirect to fmt::Debug for convenience.
+impl fmt::Display for Chipset {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "{:?}", self)
+    }
+}
+
+// TODO replace with something like derive(FromPrimitive)
+impl TryFrom<u32> for Chipset {
+    type Error = kernel::error::Error;
+
+    fn try_from(value: u32) -> Result<Self, Self::Error> {
+        match value {
+            0x162 => Ok(Chipset::TU102),
+            0x164 => Ok(Chipset::TU104),
+            0x166 => Ok(Chipset::TU106),
+            0x167 => Ok(Chipset::TU117),
+            0x168 => Ok(Chipset::TU116),
+            0x172 => Ok(Chipset::GA102),
+            0x173 => Ok(Chipset::GA103),
+            0x174 => Ok(Chipset::GA104),
+            0x176 => Ok(Chipset::GA106),
+            0x177 => Ok(Chipset::GA107),
+            0x192 => Ok(Chipset::AD102),
+            0x193 => Ok(Chipset::AD103),
+            0x194 => Ok(Chipset::AD104),
+            0x196 => Ok(Chipset::AD106),
+            0x197 => Ok(Chipset::AD107),
+            _ => Err(ENODEV),
+        }
+    }
+}
+
+/// Enum representation of the GPU generation.
+#[derive(fmt::Debug)]
+pub(crate) enum Architecture {
+    Turing,
+    Ampere,
+    Ada,
+}
+
+pub(crate) struct Revision {
+    major: u8,
+    minor: u8,
+}
+
+impl Revision {
+    fn from_boot0(boot0: regs::Boot0) -> Self {
+        Self {
+            major: boot0.major_rev(),
+            minor: boot0.minor_rev(),
+        }
+    }
+}
+
+impl fmt::Display for Revision {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "{:x}.{:x}", self.major, self.minor)
+    }
+}
+
+/// Structure holding the metadata of the GPU.
+pub(crate) struct Spec {
+    chipset: Chipset,
+    /// The revision of the chipset.
+    revision: Revision,
+}
+
+impl Spec {
+    fn new(bar: &Devres<Bar0>) -> Result<Spec> {
+        let bar = bar.try_access().ok_or(ENXIO)?;
+        let boot0 = regs::Boot0::read(&bar);
+
+        Ok(Self {
+            chipset: boot0.chipset().try_into()?,
+            revision: Revision::from_boot0(boot0),
+        })
+    }
+}
+
+/// Structure encapsulating the firmware blobs required for the GPU to operate.
+#[expect(dead_code)]
+pub(crate) struct Firmware {
+    booter_load: firmware::Firmware,
+    booter_unload: firmware::Firmware,
+    bootloader: firmware::Firmware,
+    gsp: firmware::Firmware,
+}
+
+impl Firmware {
+    fn new(dev: &device::Device, spec: &Spec, ver: &str) -> Result<Firmware> {
+        let mut chip_name = CString::try_from_fmt(fmt!("{}", spec.chipset))?;
+        chip_name.make_ascii_lowercase();
+
+        let request = |name_| {
+            CString::try_from_fmt(fmt!("nvidia/{}/gsp/{}-{}.bin", &*chip_name, name_, ver))
+                .and_then(|path| firmware::Firmware::request(&path, dev))
+        };
+
+        Ok(Firmware {
+            booter_load: request("booter_load")?,
+            booter_unload: request("booter_unload")?,
+            bootloader: request("bootloader")?,
+            gsp: request("gsp")?,
+        })
+    }
+}
+
+/// Structure holding the resources required to operate the GPU.
+#[pin_data]
+pub(crate) struct Gpu {
+    spec: Spec,
+    /// MMIO mapping of PCI BAR 0
+    bar: Devres<Bar0>,
+    fw: Firmware,
+}
+
+impl Gpu {
+    pub(crate) fn new(pdev: &pci::Device, bar: Devres<Bar0>) -> Result<impl PinInit<Self>> {
+        let spec = Spec::new(&bar)?;
+        let fw = Firmware::new(pdev.as_ref(), &spec, "535.113.01")?;
+
+        dev_info!(
+            pdev.as_ref(),
+            "NVIDIA (Chipset: {}, Architecture: {:?}, Revision: {})\n",
+            spec.chipset,
+            spec.chipset.arch(),
+            spec.revision
+        );
+
+        Ok(pin_init!(Self { spec, bar, fw }))
+    }
+}
diff --git a/drivers/gpu/nova-core/nova_core.rs b/drivers/gpu/nova-core/nova_core.rs
new file mode 100644
index 000000000000..8479be2a3f31
--- /dev/null
+++ b/drivers/gpu/nova-core/nova_core.rs
@@ -0,0 +1,19 @@
+// SPDX-License-Identifier: GPL-2.0
+
+//! Nova Core GPU Driver
+
+mod driver;
+mod firmware;
+mod gpu;
+mod regs;
+
+kernel::module_pci_driver! {
+    type: driver::NovaCore,
+    name: "NovaCore",
+    author: "Danilo Krummrich",
+    description: "Nova Core GPU driver",
+    license: "GPL v2",
+    firmware: [],
+}
+
+kernel::module_firmware!(firmware::ModInfoBuilder);
diff --git a/drivers/gpu/nova-core/regs.rs b/drivers/gpu/nova-core/regs.rs
new file mode 100644
index 000000000000..50aefb150b0b
--- /dev/null
+++ b/drivers/gpu/nova-core/regs.rs
@@ -0,0 +1,55 @@
+// SPDX-License-Identifier: GPL-2.0
+
+use crate::driver::Bar0;
+
+// TODO
+//
+// Create register definitions via generic macros. See task "Generic register
+// abstraction" in Documentation/gpu/nova/core/todo.rst.
+
+const BOOT0_OFFSET: usize = 0x00000000;
+
+// 3:0 - chipset minor revision
+const BOOT0_MINOR_REV_SHIFT: u8 = 0;
+const BOOT0_MINOR_REV_MASK: u32 = 0x0000000f;
+
+// 7:4 - chipset major revision
+const BOOT0_MAJOR_REV_SHIFT: u8 = 4;
+const BOOT0_MAJOR_REV_MASK: u32 = 0x000000f0;
+
+// 23:20 - chipset implementation Identifier (depends on architecture)
+const BOOT0_IMPL_SHIFT: u8 = 20;
+const BOOT0_IMPL_MASK: u32 = 0x00f00000;
+
+// 28:24 - chipset architecture identifier
+const BOOT0_ARCH_MASK: u32 = 0x1f000000;
+
+// 28:20 - chipset identifier (virtual register field combining BOOT0_IMPL and
+//         BOOT0_ARCH)
+const BOOT0_CHIPSET_SHIFT: u8 = BOOT0_IMPL_SHIFT;
+const BOOT0_CHIPSET_MASK: u32 = BOOT0_IMPL_MASK | BOOT0_ARCH_MASK;
+
+#[derive(Copy, Clone)]
+pub(crate) struct Boot0(u32);
+
+impl Boot0 {
+    #[inline]
+    pub(crate) fn read(bar: &Bar0) -> Self {
+        Self(bar.readl(BOOT0_OFFSET))
+    }
+
+    #[inline]
+    pub(crate) fn chipset(&self) -> u32 {
+        (self.0 & BOOT0_CHIPSET_MASK) >> BOOT0_CHIPSET_SHIFT
+    }
+
+    #[inline]
+    pub(crate) fn minor_rev(&self) -> u8 {
+        ((self.0 & BOOT0_MINOR_REV_MASK) >> BOOT0_MINOR_REV_SHIFT) as u8
+    }
+
+    #[inline]
+    pub(crate) fn major_rev(&self) -> u8 {
+        ((self.0 & BOOT0_MAJOR_REV_MASK) >> BOOT0_MAJOR_REV_SHIFT) as u8
+    }
+}
diff --git a/drivers/video/Kconfig b/drivers/video/Kconfig
index 44c9ef1435a2..5df981920a94 100644
--- a/drivers/video/Kconfig
+++ b/drivers/video/Kconfig
@@ -39,6 +39,7 @@ source "drivers/gpu/vga/Kconfig"
 
 source "drivers/gpu/host1x/Kconfig"
 source "drivers/gpu/ipu-v3/Kconfig"
+source "drivers/gpu/nova-core/Kconfig"
 
 source "drivers/gpu/drm/Kconfig"
 
-- 
2.48.1

[PATCH v4 6/6] gpu: nova-core: add initial documentation

[Danilo Krummrich]

Add the initial documentation of the Nova project.

The initial project documentation consists out of a brief introduction
of the project, as well as project guidelines both general and nova-core
specific and a task list for nova-core specifically.

The task list is divided into tasks for general Rust infrastructure
required by the project, tasks regarding GSP enablement and firmware
abstraction, general GPU driver tasks as well as tasks related to
external API design and test infrastructure.

Signed-off-by: Danilo Krummrich <dakr@kernel.org>
---
 Documentation/gpu/drivers.rst              |   1 +
 Documentation/gpu/nova/core/guidelines.rst |  24 ++
 Documentation/gpu/nova/core/todo.rst       | 446 +++++++++++++++++++++
 Documentation/gpu/nova/guidelines.rst      |  69 ++++
 Documentation/gpu/nova/index.rst           |  30 ++
 MAINTAINERS                                |   1 +
 6 files changed, 571 insertions(+)
 create mode 100644 Documentation/gpu/nova/core/guidelines.rst
 create mode 100644 Documentation/gpu/nova/core/todo.rst
 create mode 100644 Documentation/gpu/nova/guidelines.rst
 create mode 100644 Documentation/gpu/nova/index.rst

diff --git a/Documentation/gpu/drivers.rst b/Documentation/gpu/drivers.rst
index 1f17ad0790d7..7c2c5dcb5fd4 100644
--- a/Documentation/gpu/drivers.rst
+++ b/Documentation/gpu/drivers.rst
@@ -24,6 +24,7 @@ GPU Driver Documentation
    panfrost
    panthor
    zynqmp
+   nova/index
 
 .. only::  subproject and html
 
diff --git a/Documentation/gpu/nova/core/guidelines.rst b/Documentation/gpu/nova/core/guidelines.rst
new file mode 100644
index 000000000000..a389d65d7982
--- /dev/null
+++ b/Documentation/gpu/nova/core/guidelines.rst
@@ -0,0 +1,24 @@
+.. SPDX-License-Identifier: (GPL-2.0+ OR MIT)
+
+==========
+Guidelines
+==========
+
+This documents contains the guidelines for nova-core. Additionally, all common
+guidelines of the Nova project do apply.
+
+Driver API
+==========
+
+One main purpose of nova-core is to implement the abstraction around the
+firmware interface of GSP and provide a firmware (version) independent API for
+2nd level drivers, such as nova-drm or the vGPU manager VFIO driver.
+
+Therefore, it is not permitted to leak firmware (version) specifics, through the
+driver API, to 2nd level drivers.
+
+Acceptance Criteria
+===================
+
+- To the extend possible, patches submitted to nova-core must be tested for
+  regressions with all 2nd level drivers.
diff --git a/Documentation/gpu/nova/core/todo.rst b/Documentation/gpu/nova/core/todo.rst
new file mode 100644
index 000000000000..3e8d2125da9d
--- /dev/null
+++ b/Documentation/gpu/nova/core/todo.rst
@@ -0,0 +1,446 @@
+.. SPDX-License-Identifier: (GPL-2.0+ OR MIT)
+
+=========
+Task List
+=========
+
+Tasks may have the following fields:
+
+- ``Complexity``: Describes the required familiarity with Rust and / or the
+  corresponding kernel APIs or subsystems. There are four different complexities,
+  ``Beginner``, ``Intermediate``, ``Advanced`` and ``Expert``.
+- ``Reference``: References to other tasks.
+- ``Link``: Links to external resources.
+- ``Contact``: The person that can be contacted for further information about
+  the task.
+
+Enablement (Rust)
+=================
+
+Tasks that are not directly related to nova-core, but are preconditions in terms
+of required APIs.
+
+FromPrimitive API
+-----------------
+
+Sometimes the need arises to convert a number to a value of an enum or a
+structure.
+
+A good example from nova-core would be the ``Chipset`` enum type, which defines
+the value ``AD102``. When probing the GPU the value ``0x192`` can be read from a
+certain register indication the chipset AD102. Hence, the enum value ``AD102``
+should be derived from the number ``0x192``. Currently, nova-core uses a custom
+implementation (``Chipset::from_u32`` for this.
+
+Instead, it would be desirable to have something like the ``FromPrimitive``
+trait [1] from the num crate.
+
+Having this generalization also helps with implementing a generic macro that
+automatically generates the corresponding mappings between a value and a number.
+
+| Complexity: Beginner
+| Link: https://docs.rs/num/latest/num/trait.FromPrimitive.html
+
+Generic register abstraction
+----------------------------
+
+Work out how register constants and structures can be automatically generated
+through generalized macros.
+
+Example:
+
+.. code-block:: rust
+
+	register!(BOOT0, 0x0, u32, pci::Bar<SIZE>, Fields [
+	   MINOR_REVISION(3:0, RO),
+	   MAJOR_REVISION(7:4, RO),
+	   REVISION(7:0, RO), // Virtual register combining major and minor rev.
+	])
+
+This could expand to something like:
+
+.. code-block:: rust
+
+	const BOOT0_OFFSET: usize = 0x00000000;
+	const BOOT0_MINOR_REVISION_SHIFT: u8 = 0;
+	const BOOT0_MINOR_REVISION_MASK: u32 = 0x0000000f;
+	const BOOT0_MAJOR_REVISION_SHIFT: u8 = 4;
+	const BOOT0_MAJOR_REVISION_MASK: u32 = 0x000000f0;
+	const BOOT0_REVISION_SHIFT: u8 = BOOT0_MINOR_REVISION_SHIFT;
+	const BOOT0_REVISION_MASK: u32 = BOOT0_MINOR_REVISION_MASK | BOOT0_MAJOR_REVISION_MASK;
+
+	struct Boot0(u32);
+
+	impl Boot0 {
+	   #[inline]
+	   fn read(bar: &RevocableGuard<'_, pci::Bar<SIZE>>) -> Self {
+	      Self(bar.readl(BOOT0_OFFSET))
+	   }
+
+	   #[inline]
+	   fn minor_revision(&self) -> u32 {
+	      (self.0 & BOOT0_MINOR_REVISION_MASK) >> BOOT0_MINOR_REVISION_SHIFT
+	   }
+
+	   #[inline]
+	   fn major_revision(&self) -> u32 {
+	      (self.0 & BOOT0_MAJOR_REVISION_MASK) >> BOOT0_MAJOR_REVISION_SHIFT
+	   }
+
+	   #[inline]
+	   fn revision(&self) -> u32 {
+	      (self.0 & BOOT0_REVISION_MASK) >> BOOT0_REVISION_SHIFT
+	   }
+	}
+
+Usage:
+
+.. code-block:: rust
+
+	let bar = bar.try_access().ok_or(ENXIO)?;
+
+	let boot0 = Boot0::read(&bar);
+	pr_info!("Revision: {}\n", boot0.revision());
+
+| Complexity: Advanced
+
+Delay / Sleep abstractions
+--------------------------
+
+Rust abstractions for the kernel's delay() and sleep() functions.
+
+There is some ongoing work from FUJITA Tomonori [1], which has not seen any updates
+since Oct. 24.
+
+| Complexity: Beginner
+| Link: https://lore.kernel.org/netdev/20241001112512.4861-2-fujita.tomonori@gmail.com/ [1]
+
+IRQ abstractions
+----------------
+
+Rust abstractions for IRQ handling.
+
+There is active ongoing work from Daniel Almeida [1] for the "core" abstractions
+to request IRQs.
+
+Besides optional review and testing work, the required ``pci::Device`` code
+around those core abstractions needs to be worked out.
+
+| Complexity: Intermediate
+| Link: https://lore.kernel.org/lkml/20250122163932.46697-1-daniel.almeida@collabora.com/ [1]
+| Contact: Daniel Almeida
+
+Page abstraction for foreign pages
+----------------------------------
+
+Rust abstractions for pages not created by the Rust page abstraction without
+direct ownership.
+
+There is active onging work from Abdiel Janulgue [1] and Lina [2].
+
+| Complexity: Advanced
+| Link: https://lore.kernel.org/linux-mm/20241119112408.779243-1-abdiel.janulgue@gmail.com/ [1]
+| Link: https://lore.kernel.org/rust-for-linux/20250202-rust-page-v1-0-e3170d7fe55e@asahilina.net/ [2]
+
+Scatterlist / sg_table abstractions
+-----------------------------------
+
+Rust abstractions for scatterlist / sg_table.
+
+There is preceding work from Abdiel Janulgue, which hasn't made it to the
+mailing list yet.
+
+| Complexity: Intermediate
+| Contact: Abdiel Janulgue
+
+ELF utils
+---------
+
+Rust implementation of ELF header representation to retrieve section header
+tables, names, and data from an ELF-formatted images.
+
+There is preceding work from Abdiel Janulgue, which hasn't made it to the
+mailing list yet.
+
+| Complexity: Beginner
+| Contact: Abdiel Janulgue
+
+PCI MISC APIs
+-------------
+
+Extend the existing PCI device / driver abstractions by SR-IOV, config space,
+capability, MSI API abstractions.
+
+| Complexity: Beginner
+
+Auxiliary bus abstractions
+--------------------------
+
+Rust abstraction for the auxiliary bus APIs.
+
+This is needed to connect nova-core to the nova-drm driver.
+
+| Complexity: Intermediate
+
+Debugfs abstractions
+--------------------
+
+Rust abstraction for debugfs APIs.
+
+| Reference: Export GSP log buffers
+| Complexity: Intermediate
+
+Vec extensions
+--------------
+
+Implement ``Vec::truncate`` and ``Vec::resize``.
+
+Currently this is used for some experimental code to parse the vBIOS.
+
+| Reference vBIOS support
+| Complexity: Beginner
+
+GPU (general)
+=============
+
+Parse firmware headers
+----------------------
+
+Parse ELF headers from the firmware files loaded from the filesystem.
+
+| Reference: ELF utils
+| Complexity: Beginner
+| Contact: Abdiel Janulgue
+
+Build radix3 page table
+-----------------------
+
+Build the radix3 page table to map the firmware.
+
+| Complexity: Intermediate
+| Contact: Abdiel Janulgue
+
+vBIOS support
+-------------
+
+Parse the vBIOS and probe the structures required for driver initialization.
+
+| Contact: Dave Airlie
+| Reference: Vec extensions
+| Complexity: Intermediate
+
+Initial Devinit support
+-----------------------
+
+Implement BIOS Device Initialization, i.e. memory sizing, waiting, PLL
+configuration.
+
+| Contact: Dave Airlie
+| Complexity: Beginner
+
+Boot Falcon controller
+----------------------
+
+Infrastructure to load and execute falcon (sec2) firmware images; handle the
+GSP falcon processor and fwsec loading.
+
+| Complexity: Advanced
+| Contact: Dave Airlie
+
+GPU Timer support
+-----------------
+
+Support for the GPU's internal timer peripheral.
+
+| Complexity: Beginner
+| Contact: Dave Airlie
+
+MMU / PT management
+-------------------
+
+Work out the architecture for MMU / page table management.
+
+We need to consider that nova-drm will need rather fine-grained control,
+especially in terms of locking, in order to be able to implement asynchronous
+Vulkan queues.
+
+While generally sharing the corresponding code is desirable, it needs to be
+evaluated how (and if at all) sharing the corresponding code is expedient.
+
+| Complexity: Expert
+
+VRAM memory allocator
+---------------------
+
+Investigate options for a VRAM memory allocator.
+
+Some possible options:
+  - Rust abstractions for
+    - RB tree (interval tree) / drm_mm
+    - maple_tree
+  - native Rust collections
+
+| Complexity: Advanced
+
+Instance Memory
+---------------
+
+Implement support for instmem (bar2) used to store page tables.
+
+| Complexity: Intermediate
+| Contact: Dave Airlie
+
+GPU System Processor (GSP)
+==========================
+
+Export GSP log buffers
+----------------------
+
+Recent patches from Timur Tabi [1] added support to expose GSP-RM log buffers
+(even after failure to probe the driver) through debugfs.
+
+This is also an interesting feature for nova-core, especially in the early days.
+
+| Link: https://lore.kernel.org/nouveau/20241030202952.694055-2-ttabi@nvidia.com/ [1]
+| Reference: Debugfs abstractions
+| Complexity: Intermediate
+
+GSP firmware abstraction
+------------------------
+
+The GSP-RM firmware API is unstable and may incompatibly change from version to
+version, in terms of data structures and semantics.
+
+This problem is one of the big motivations for using Rust for nova-core, since
+it turns out that Rust's procedural macro feature provides a rather elegant way
+to address this issue:
+
+1. generate Rust structures from the C headers in a separate namespace per version
+2. build abstraction structures (within a generic namespace) that implement the
+   firmware interfaces; annotate the differences in implementation with version
+   identifiers
+3. use a procedural macro to generate the actual per version implementation out
+   of this abstraction
+4. instantiate the correct version type one on runtime (can be sure that all
+   have the same interface because it's defined by a common trait)
+
+There is a PoC implementation of this pattern, in the context of the nova-core
+PoC driver.
+
+This task aims at refining the feature and ideally generalize it, to be usable
+by other drivers as well.
+
+| Complexity: Expert
+
+GSP message queue
+-----------------
+
+Implement low level GSP message queue (command, status) for communication
+between the kernel driver and GSP.
+
+| Complexity: Advanced
+| Contact: Dave Airlie
+
+Bootstrap GSP
+-------------
+
+Call the boot firmware to boot the GSP processor; execute initial control
+messages.
+
+| Complexity: Intermediate
+| Contact: Dave Airlie
+
+Client / Device APIs
+--------------------
+
+Implement the GSP message interface for client / device allocation and the
+corresponding client and device allocation APIs.
+
+| Complexity: Intermediate
+| Contact: Dave Airlie
+
+Bar PDE handling
+----------------
+
+Synchronize page table handling for BARs between the kernel driver and GSP.
+
+| Complexity: Beginner
+| Contact: Dave Airlie
+
+FIFO engine
+-----------
+
+Implement support for the FIFO engine, i.e. the corresponding GSP message
+interface and provide an API for chid allocation and channel handling.
+
+| Complexity: Advanced
+| Contact: Dave Airlie
+
+GR engine
+---------
+
+Implement support for the graphics engine, i.e. the corresponding GSP message
+interface and provide an API for (golden) context creation and promotion.
+
+| Complexity: Advanced
+| Contact: Dave Airlie
+
+CE engine
+---------
+
+Implement support for the copy engine, i.e. the corresponding GSP message
+interface.
+
+| Complexity: Intermediate
+| Contact: Dave Airlie
+
+VFN IRQ controller
+------------------
+
+Support for the VFN interrupt controller.
+
+| Complexity: Intermediate
+| Contact: Dave Airlie
+
+External APIs
+=============
+
+nova-core base API
+------------------
+
+Work out the common pieces of the API to connect 2nd level drivers, i.e. vGPU
+manager and nova-drm.
+
+| Complexity: Advanced
+
+vGPU manager API
+----------------
+
+Work out the API parts required by the vGPU manager, which are not covered by
+the base API.
+
+| Complexity: Advanced
+
+nova-core C API
+---------------
+
+Implement a C wrapper for the APIs required by the vGPU manager driver.
+
+| Complexity: Intermediate
+
+Testing
+=======
+
+CI pipeline
+-----------
+
+Investigate option for continuous integration testing.
+
+This can go from as simple as running KUnit tests over running (graphics) CTS to
+booting up (multiple) guest VMs to test VFIO use-cases.
+
+It might also be worth to consider the introduction of a new test suite directly
+sitting on top of the uAPI for more targeted testing and debugging. There may be
+options for collaboration / shared code with the Mesa project.
+
+| Complexity: Advanced
diff --git a/Documentation/gpu/nova/guidelines.rst b/Documentation/gpu/nova/guidelines.rst
new file mode 100644
index 000000000000..13ab13984a18
--- /dev/null
+++ b/Documentation/gpu/nova/guidelines.rst
@@ -0,0 +1,69 @@
+.. SPDX-License-Identifier: (GPL-2.0+ OR MIT)
+
+==========
+Guidelines
+==========
+
+This document describes the general project guidelines that apply to nova-core
+and nova-drm.
+
+Language
+========
+
+The Nova project uses the Rust programming language. In this context, all rules
+of the Rust for Linux project as documented in
+:doc:`../../rust/general-information` apply. Additionally, the following rules
+apply.
+
+- Unless technically necessary otherwise (e.g. uAPI), any driver code is written
+  in Rust.
+
+- Unless technically necessary, unsafe Rust code must be avoided. In case of
+  technical necessity, unsafe code should be isolated in a separate component
+  providing a safe API for other driver code to use.
+
+Style
+-----
+
+All rules of the Rust for Linux project as documented in
+:doc:`../../rust/coding-guidelines` apply.
+
+For a submit checklist, please also see the `Rust for Linux Submit checklist
+addendum <https://rust-for-linux.com/contributing#submit-checklist-addendum>`_.
+
+Documentation
+=============
+
+The availability of proper documentation is essential in terms of scalability,
+accessibility for new contributors and maintainability of a project in general,
+but especially for a driver running as complex hardware as Nova is targeting.
+
+Hence, adding documentation of any kind is very much encouraged by the project.
+
+Besides that, there are some minimum requirements.
+
+- Every non-private structure needs at least a brief doc comment explaining the
+  semantical sense of the structure, as well as potential locking and lifetime
+  requirements. It is encouraged to have the same minimum documentation for
+  non-trivial private structures.
+
+- uAPIs must be fully documented with kernel-doc comments; additionally, the
+  semantical behavior must be explained including potential special or corner
+  cases.
+
+- The APIs connecting the 1st level driver (nova-core) with 2nd level drivers
+  must be fully documented. This includes doc comments, potential locking and
+  lifetime requirements, as well as example code if applicable.
+
+- Abbreviations must be explained when introduced; terminology must be uniquely
+  defined.
+
+- Register addresses, layouts, shift values and masks must be defined properly;
+  unless obvious, the semantical sense must be documented. This only applies if
+  the author is able to obtain the corresponding information.
+
+Acceptance Criteria
+===================
+
+- Patches must only be applied if reviewed by at least one other person on the
+  mailing list; this also applies for maintainers.
diff --git a/Documentation/gpu/nova/index.rst b/Documentation/gpu/nova/index.rst
new file mode 100644
index 000000000000..2701b3f4af35
--- /dev/null
+++ b/Documentation/gpu/nova/index.rst
@@ -0,0 +1,30 @@
+.. SPDX-License-Identifier: (GPL-2.0+ OR MIT)
+
+=======================
+nova NVIDIA GPU drivers
+=======================
+
+The nova driver project consists out of two separate drivers nova-core and
+nova-drm and intends to supersede the nouveau driver for NVIDIA GPUs based on
+the GPU System Processor (GSP).
+
+The following documents apply to both nova-core and nova-drm.
+
+.. toctree::
+   :titlesonly:
+
+   guidelines
+
+nova-core
+=========
+
+The nova-core driver is the core driver for NVIDIA GPUs based on GSP. nova-core,
+as the 1st level driver, provides an abstraction around the GPUs hard- and
+firmware interfaces providing a common base for 2nd level drivers, such as the
+vGPU manager VFIO driver and the nova-drm driver.
+
+.. toctree::
+   :titlesonly:
+
+   core/guidelines
+   core/todo
diff --git a/MAINTAINERS b/MAINTAINERS
index 3c8a3b61af38..32300118b9a3 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -7446,6 +7446,7 @@ Q:	https://patchwork.freedesktop.org/project/nouveau/
 B:	https://gitlab.freedesktop.org/drm/nova/-/issues
 C:	irc://irc.oftc.net/nouveau
 T:	git https://gitlab.freedesktop.org/drm/nova.git nova-next
+F:	Documentation/gpu/nova/
 F:	drivers/gpu/nova-core/
 
 DRM DRIVER FOR OLIMEX LCD-OLINUXINO PANELS
-- 
2.48.1

Re: [PATCH v4 5/6] gpu: nova-core: add initial driver stub

[Alexandre Courbot]

Hi Danilo,

On Thu Feb 27, 2025 at 2:55 AM JST, Danilo Krummrich wrote:
> Add the initial nova-core driver stub.
>
> nova-core is intended to serve as a common base for nova-drm (the
> corresponding DRM driver) and the vGPU manager VFIO driver, serving as a
> hard- and firmware abstraction layer for GSP-based NVIDIA GPUs.
>
> The Nova project, including nova-core and nova-drm, in the long term,
> is intended to serve as the successor of Nouveau for all GSP-based GPUs.
>
> The motivation for both, starting a successor project for Nouveau and
> doing so using the Rust programming language, is documented in detail
> through a previous post on the mailing list [1], an LWN article [2] and a
> talk from LPC '24.
>
> In order to avoid the chicken and egg problem to require a user to
> upstream Rust abstractions, but at the same time require the Rust
> abstractions to implement the driver, nova-core kicks off as a driver
> stub and is subsequently developed upstream.
>
> Link: https://lore.kernel.org/dri-devel/Zfsj0_tb-0-tNrJy@cassiopeiae/T/#u [1]
> Link: https://lwn.net/Articles/990736/ [2]
> Link: https://youtu.be/3Igmx28B3BQ?si=sBdSEer4tAPKGpOs [3]
> Signed-off-by: Danilo Krummrich <dakr@kernel.org>
> ---
>  MAINTAINERS                        |  10 ++
>  drivers/gpu/Makefile               |   1 +
>  drivers/gpu/nova-core/Kconfig      |  14 ++
>  drivers/gpu/nova-core/Makefile     |   3 +
>  drivers/gpu/nova-core/driver.rs    |  47 ++++++
>  drivers/gpu/nova-core/firmware.rs  |  45 ++++++
>  drivers/gpu/nova-core/gpu.rs       | 225 +++++++++++++++++++++++++++++
>  drivers/gpu/nova-core/nova_core.rs |  19 +++
>  drivers/gpu/nova-core/regs.rs      |  55 +++++++
>  drivers/video/Kconfig              |   1 +
>  10 files changed, 420 insertions(+)
>  create mode 100644 drivers/gpu/nova-core/Kconfig
>  create mode 100644 drivers/gpu/nova-core/Makefile
>  create mode 100644 drivers/gpu/nova-core/driver.rs
>  create mode 100644 drivers/gpu/nova-core/firmware.rs
>  create mode 100644 drivers/gpu/nova-core/gpu.rs
>  create mode 100644 drivers/gpu/nova-core/nova_core.rs
>  create mode 100644 drivers/gpu/nova-core/regs.rs
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 1b0cc181db74..3c8a3b61af38 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -7438,6 +7438,16 @@ T:	git https://gitlab.freedesktop.org/drm/nouveau.git
>  F:	drivers/gpu/drm/nouveau/
>  F:	include/uapi/drm/nouveau_drm.h
>  
> +CORE DRIVER FOR NVIDIA GPUS [RUST]
> +M:	Danilo Krummrich <dakr@kernel.org>
> +L:	nouveau@lists.freedesktop.org
> +S:	Supported
> +Q:	https://patchwork.freedesktop.org/project/nouveau/
> +B:	https://gitlab.freedesktop.org/drm/nova/-/issues
> +C:	irc://irc.oftc.net/nouveau
> +T:	git https://gitlab.freedesktop.org/drm/nova.git nova-next
> +F:	drivers/gpu/nova-core/
> +
>  DRM DRIVER FOR OLIMEX LCD-OLINUXINO PANELS
>  M:	Stefan Mavrodiev <stefan@olimex.com>
>  S:	Maintained
> diff --git a/drivers/gpu/Makefile b/drivers/gpu/Makefile
> index 8997f0096545..36a54d456630 100644
> --- a/drivers/gpu/Makefile
> +++ b/drivers/gpu/Makefile
> @@ -5,3 +5,4 @@
>  obj-y			+= host1x/ drm/ vga/
>  obj-$(CONFIG_IMX_IPUV3_CORE)	+= ipu-v3/
>  obj-$(CONFIG_TRACE_GPU_MEM)		+= trace/
> +obj-$(CONFIG_NOVA_CORE)		+= nova-core/
> diff --git a/drivers/gpu/nova-core/Kconfig b/drivers/gpu/nova-core/Kconfig
> new file mode 100644
> index 000000000000..ad0c06756516
> --- /dev/null
> +++ b/drivers/gpu/nova-core/Kconfig
> @@ -0,0 +1,14 @@
> +config NOVA_CORE
> +	tristate "Nova Core GPU driver"
> +	depends on PCI
> +	depends on RUST
> +	depends on RUST_FW_LOADER_ABSTRACTIONS
> +	default n
> +	help
> +	  Choose this if you want to build the Nova Core driver for Nvidia
> +	  GPUs based on the GPU System Processor (GSP). This is true for Turing
> +	  and later GPUs.
> +
> +	  This driver is work in progress and may not be functional.
> +
> +	  If M is selected, the module will be called nova_core.
> diff --git a/drivers/gpu/nova-core/Makefile b/drivers/gpu/nova-core/Makefile
> new file mode 100644
> index 000000000000..2d78c50126e1
> --- /dev/null
> +++ b/drivers/gpu/nova-core/Makefile
> @@ -0,0 +1,3 @@
> +# SPDX-License-Identifier: GPL-2.0
> +
> +obj-$(CONFIG_NOVA_CORE) += nova_core.o
> diff --git a/drivers/gpu/nova-core/driver.rs b/drivers/gpu/nova-core/driver.rs
> new file mode 100644
> index 000000000000..63c19f140fbd
> --- /dev/null
> +++ b/drivers/gpu/nova-core/driver.rs
> @@ -0,0 +1,47 @@
> +// SPDX-License-Identifier: GPL-2.0
> +
> +use kernel::{bindings, c_str, pci, prelude::*};
> +
> +use crate::gpu::Gpu;
> +
> +#[pin_data]
> +pub(crate) struct NovaCore {
> +    #[pin]
> +    pub(crate) gpu: Gpu,
> +}
> +
> +const BAR0_SIZE: usize = 8;
> +pub(crate) type Bar0 = pci::Bar<BAR0_SIZE>;
> +
> +kernel::pci_device_table!(
> +    PCI_TABLE,
> +    MODULE_PCI_TABLE,
> +    <NovaCore as pci::Driver>::IdInfo,
> +    [(
> +        pci::DeviceId::from_id(bindings::PCI_VENDOR_ID_NVIDIA, bindings::PCI_ANY_ID as _),
> +        ()
> +    )]
> +);
> +
> +impl pci::Driver for NovaCore {
> +    type IdInfo = ();
> +    const ID_TABLE: pci::IdTable<Self::IdInfo> = &PCI_TABLE;
> +
> +    fn probe(pdev: &mut pci::Device, _info: &Self::IdInfo) -> Result<Pin<KBox<Self>>> {
> +        dev_dbg!(pdev.as_ref(), "Probe Nova Core GPU driver.\n");
> +
> +        pdev.enable_device_mem()?;
> +        pdev.set_master();
> +
> +        let bar = pdev.iomap_region_sized::<BAR0_SIZE>(0, c_str!("nova-core/bar0"))?;
> +
> +        let this = KBox::pin_init(
> +            try_pin_init!(Self {
> +                gpu <- Gpu::new(pdev, bar)?,
> +            }),
> +            GFP_KERNEL,
> +        )?;
> +
> +        Ok(this)
> +    }
> +}
> diff --git a/drivers/gpu/nova-core/firmware.rs b/drivers/gpu/nova-core/firmware.rs
> new file mode 100644
> index 000000000000..a94caa7cf8d3
> --- /dev/null
> +++ b/drivers/gpu/nova-core/firmware.rs
> @@ -0,0 +1,45 @@
> +// SPDX-License-Identifier: GPL-2.0
> +
> +use crate::gpu;
> +use kernel::firmware;
> +
> +pub(crate) struct ModInfoBuilder<const N: usize>(firmware::ModInfoBuilder<N>);
> +
> +impl<const N: usize> ModInfoBuilder<N> {
> +    const fn make_entry_file(self, chipset: &[u8], fw: &[u8]) -> Self {
> +        let version = b"535.113.01";
> +
> +        ModInfoBuilder(
> +            self.0
> +                .prepare()
> +                .push(b"nvidia/")
> +                .push(chipset)
> +                .push(b"/gsp/")
> +                .push(fw)
> +                .push(b"-")
> +                .push(version)
> +                .push(b".bin"),
> +        )
> +    }
> +
> +    const fn make_entry_chipset(self, chipset: &[u8]) -> Self {
> +        self.make_entry_file(chipset, b"booter_load")
> +            .make_entry_file(chipset, b"booter_unload")
> +            .make_entry_file(chipset, b"bootloader")
> +            .make_entry_file(chipset, b"gsp")
> +    }
> +
> +    pub(crate) const fn create(
> +        module_name: &'static kernel::str::CStr,
> +    ) -> firmware::ModInfoBuilder<N> {
> +        let mut this = Self(firmware::ModInfoBuilder::new(module_name));
> +        let mut i = 0;
> +
> +        while i < gpu::Chipset::NAMES.len() {
> +            this = this.make_entry_chipset(gpu::Chipset::NAMES[i].as_bytes());
> +            i += 1;
> +        }
> +
> +        this.0
> +    }
> +}
> diff --git a/drivers/gpu/nova-core/gpu.rs b/drivers/gpu/nova-core/gpu.rs
> new file mode 100644
> index 000000000000..7693a5df0dc1
> --- /dev/null
> +++ b/drivers/gpu/nova-core/gpu.rs
> @@ -0,0 +1,225 @@
> +// SPDX-License-Identifier: GPL-2.0
> +
> +use kernel::{
> +    device, devres::Devres, error::code::*, firmware, fmt, pci, prelude::*, str::BStr, str::CString,
> +};
> +
> +use crate::driver::Bar0;
> +use crate::regs;
> +use core::fmt;
> +
> +const fn to_lowercase_bytes<const N: usize>(s: &str) -> [u8; N] {
> +    let src = s.as_bytes();
> +    let mut dst = [0; N];
> +    let mut i = 0;
> +
> +    while i < src.len() && i < N {
> +        dst[i] = (src[i] as char).to_ascii_lowercase() as u8;
> +        i += 1;
> +    }
> +
> +    dst
> +}
> +
> +macro_rules! define_chipset {
> +    ({ $($variant:ident = $value:expr),* $(,)* }) =>
> +    {
> +        /// Enum representation of the GPU chipset.
> +        #[derive(fmt::Debug)]
> +        pub(crate) enum Chipset {
> +            $($variant = $value),*,
> +        }
> +
> +        impl Chipset {
> +            pub(crate) const ALL: &'static [Chipset] = &[
> +                $( Chipset::$variant, )*
> +            ];
> +
> +            pub(crate) const NAMES: [&BStr; Self::ALL.len()] = [
> +                $( BStr::from_bytes(
> +                        to_lowercase_bytes::<{ stringify!($variant).len() }>(
> +                            stringify!($variant)
> +                        ).as_slice()
> +                ), )*
> +            ];
> +        }
> +    }
> +}
> +
> +define_chipset!({
> +    // Turing
> +    TU102 = 0x162,
> +    TU104 = 0x164,
> +    TU106 = 0x166,
> +    TU117 = 0x167,
> +    TU116 = 0x168,
> +    // Ampere
> +    GA102 = 0x172,
> +    GA103 = 0x173,
> +    GA104 = 0x174,
> +    GA106 = 0x176,
> +    GA107 = 0x177,
> +    // Ada
> +    AD102 = 0x192,
> +    AD103 = 0x193,
> +    AD104 = 0x194,
> +    AD106 = 0x196,
> +    AD107 = 0x197,
> +});
> +
> +impl Chipset {
> +    pub(crate) fn arch(&self) -> Architecture {
> +        match self {
> +            Self::TU102 | Self::TU104 | Self::TU106 | Self::TU117 | Self::TU116 => {
> +                Architecture::Turing
> +            }
> +            Self::GA102 | Self::GA103 | Self::GA104 | Self::GA106 | Self::GA107 => {
> +                Architecture::Ampere
> +            }
> +            Self::AD102 | Self::AD103 | Self::AD104 | Self::AD106 | Self::AD107 => {
> +                Architecture::Ada
> +            }
> +        }
> +    }
> +}
> +
> +// TODO
> +//
> +// The resulting strings are used to generate firmware paths, hence the
> +// generated strings have to be stable.
> +//
> +// Hence, replace with something like strum_macros derive(Display).
> +//
> +// For now, redirect to fmt::Debug for convenience.
> +impl fmt::Display for Chipset {
> +    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
> +        write!(f, "{:?}", self)
> +    }
> +}
> +
> +// TODO replace with something like derive(FromPrimitive)
> +impl TryFrom<u32> for Chipset {
> +    type Error = kernel::error::Error;
> +
> +    fn try_from(value: u32) -> Result<Self, Self::Error> {
> +        match value {
> +            0x162 => Ok(Chipset::TU102),
> +            0x164 => Ok(Chipset::TU104),
> +            0x166 => Ok(Chipset::TU106),
> +            0x167 => Ok(Chipset::TU117),
> +            0x168 => Ok(Chipset::TU116),
> +            0x172 => Ok(Chipset::GA102),
> +            0x173 => Ok(Chipset::GA103),
> +            0x174 => Ok(Chipset::GA104),
> +            0x176 => Ok(Chipset::GA106),
> +            0x177 => Ok(Chipset::GA107),
> +            0x192 => Ok(Chipset::AD102),
> +            0x193 => Ok(Chipset::AD103),
> +            0x194 => Ok(Chipset::AD104),
> +            0x196 => Ok(Chipset::AD106),
> +            0x197 => Ok(Chipset::AD107),
> +            _ => Err(ENODEV),
> +        }
> +    }
> +}

I know this is probably temporary anyway, but since there is a macro now you can simplify this implementation by making part of it:

		impl TryFrom<u32> for Chipset {
				type Error = kernel::error::Error;

				fn try_from(value: u32) -> Result<Self, Self::Error> {
						match value {
								$( $value => Ok(Chipset::$variant), )*
								_ => Err(ENODEV),
						}
				}
		}

Re: [PATCH v4 5/6] gpu: nova-core: add initial driver stub

[Danilo Krummrich]

On Tue, Mar 04, 2025 at 11:19:49PM +0900, Alexandre Courbot wrote:
> On Thu Feb 27, 2025 at 2:55 AM JST, Danilo Krummrich wrote:
> 
> > +// TODO replace with something like derive(FromPrimitive)
> > +impl TryFrom<u32> for Chipset {
> > +    type Error = kernel::error::Error;
> > +
> > +    fn try_from(value: u32) -> Result<Self, Self::Error> {
> > +        match value {
> > +            0x162 => Ok(Chipset::TU102),
> > +            0x164 => Ok(Chipset::TU104),
> > +            0x166 => Ok(Chipset::TU106),
> > +            0x167 => Ok(Chipset::TU117),
> > +            0x168 => Ok(Chipset::TU116),
> > +            0x172 => Ok(Chipset::GA102),
> > +            0x173 => Ok(Chipset::GA103),
> > +            0x174 => Ok(Chipset::GA104),
> > +            0x176 => Ok(Chipset::GA106),
> > +            0x177 => Ok(Chipset::GA107),
> > +            0x192 => Ok(Chipset::AD102),
> > +            0x193 => Ok(Chipset::AD103),
> > +            0x194 => Ok(Chipset::AD104),
> > +            0x196 => Ok(Chipset::AD106),
> > +            0x197 => Ok(Chipset::AD107),
> > +            _ => Err(ENODEV),
> > +        }
> > +    }
> > +}
> 
> I know this is probably temporary anyway, but since there is a macro now you can simplify this implementation by making part of it:
> 
> 		impl TryFrom<u32> for Chipset {
> 				type Error = kernel::error::Error;
> 
> 				fn try_from(value: u32) -> Result<Self, Self::Error> {
> 						match value {
> 								$( $value => Ok(Chipset::$variant), )*
> 								_ => Err(ENODEV),
> 						}
> 				}
> 		}
> 

Sure, that's a good suggestion, will do.

With that changed, may I add your RB? I'd like to land this series in the next
merge window.