rust: Add several miscellaneous PCI helpers

Add bindings to obtain a PCI device's resource start address, bus/
device function, revision ID and subsystem device and vendor IDs.

These will be used by the nova-core GPU driver which is currently in
development.

Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Cc: Danilo Krummrich <dakr@kernel.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Krzysztof Wilczyński <kwilczynski@kernel.org>
Cc: Miguel Ojeda <ojeda@kernel.org>
Cc: Alex Gaynor <alex.gaynor@gmail.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Gary Guo <gary@garyguo.net>
Cc: Björn Roy Baron <bjorn3_gh@protonmail.com>
Cc: Benno Lossin <lossin@kernel.org>
Cc: Andreas Hindborg <a.hindborg@kernel.org>
Cc: Alice Ryhl <aliceryhl@google.com>
Cc: Trevor Gross <tmgross@umich.edu>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Rafael J. Wysocki <rafael@kernel.org>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Alexandre Courbot <acourbot@nvidia.com>
Cc: linux-pci@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Alistair Popple <apopple@nvidia.com>
Link: https://lore.kernel.org/r/20250730013417.640593-2-apopple@nvidia.com
Signed-off-by: Danilo Krummrich <dakr@kernel.org>

1 files changed, 44 insertions, 0 deletions

diff --git a/rust/kernel/pci.rs b/rust/kernel/pci.rs
index 5fa74d627730..08fb69e5eb97 100644
--- a/rust/kernel/pci.rs
+++ b/rust/kernel/pci.rs
@@ -403,6 +403,50 @@ impl Device {
         unsafe { (*self.as_raw()).device }
     }
 
+    /// Returns the PCI revision ID.
+    #[inline]
+    pub fn revision_id(&self) -> u8 {
+        // SAFETY: By its type invariant `self.as_raw` is always a valid pointer to a
+        // `struct pci_dev`.
+        unsafe { (*self.as_raw()).revision }
+    }
+
+    /// Returns the PCI bus device/function.
+    #[inline]
+    pub fn dev_id(&self) -> u16 {
+        // SAFETY: By its type invariant `self.as_raw` is always a valid pointer to a
+        // `struct pci_dev`.
+        unsafe { bindings::pci_dev_id(self.as_raw()) }
+    }
+
+    /// Returns the PCI subsystem vendor ID.
+    #[inline]
+    pub fn subsystem_vendor_id(&self) -> u16 {
+        // SAFETY: By its type invariant `self.as_raw` is always a valid pointer to a
+        // `struct pci_dev`.
+        unsafe { (*self.as_raw()).subsystem_vendor }
+    }
+
+    /// Returns the PCI subsystem device ID.
+    #[inline]
+    pub fn subsystem_device_id(&self) -> u16 {
+        // SAFETY: By its type invariant `self.as_raw` is always a valid pointer to a
+        // `struct pci_dev`.
+        unsafe { (*self.as_raw()).subsystem_device }
+    }
+
+    /// Returns the start of the given PCI bar resource.
+    pub fn resource_start(&self, bar: u32) -> Result<bindings::resource_size_t> {
+        if !Bar::index_is_valid(bar) {
+            return Err(EINVAL);
+        }
+
+        // SAFETY:
+        // - `bar` is a valid bar number, as guaranteed by the above call to `Bar::index_is_valid`,
+        // - by its type invariant `self.as_raw` is always a valid pointer to a `struct pci_dev`.
+        Ok(unsafe { bindings::pci_resource_start(self.as_raw(), bar.try_into()?) })
+    }
+
     /// Returns the size of the given PCI bar resource.
     pub fn resource_len(&self, bar: u32) -> Result<bindings::resource_size_t> {
         if !Bar::index_is_valid(bar) {