From: Alistair Popple <apopple@nvidia.com>
Date: Wed, 30 Jul 2025 01:34:17 +0000 (+1000)
Subject: rust: Add several miscellaneous PCI helpers
X-Git-Tag: v6.18-rc1~172^2~33
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=b6a37d1d4694111895248b771513153ccace606a;p=thirdparty%2Fkernel%2Flinux.git

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>
---

diff --git a/rust/helpers/pci.c b/rust/helpers/pci.c
index 5bf56004478c6..fb814572b2363 100644
--- a/rust/helpers/pci.c
+++ b/rust/helpers/pci.c
@@ -2,6 +2,16 @@
 
 #include <linux/pci.h>
 
+u16 rust_helper_pci_dev_id(struct pci_dev *dev)
+{
+	return PCI_DEVID(dev->bus->number, dev->devfn);
+}
+
+resource_size_t rust_helper_pci_resource_start(struct pci_dev *pdev, int bar)
+{
+	return pci_resource_start(pdev, bar);
+}
+
 resource_size_t rust_helper_pci_resource_len(struct pci_dev *pdev, int bar)
 {
 	return pci_resource_len(pdev, bar);
diff --git a/rust/kernel/pci.rs b/rust/kernel/pci.rs
index 5fa74d6277304..08fb69e5eb975 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) {