1 files changed, 21 insertions, 1 deletions
diff --git a/rust/kernel/pci.rs b/rust/kernel/pci.rs
index 3664d35b8e79..38fc8d5ffbf9 100644
--- a/rust/kernel/pci.rs
+++ b/rust/kernel/pci.rs
@@ -6,7 +6,7 @@
 
 use crate::{
     alloc::flags::*,
-    bindings, device,
+    bindings, container_of, device,
     device_id::RawDeviceId,
     devres::Devres,
     driver,
@@ -455,6 +455,26 @@ impl<Ctx: device::DeviceContext> AsRef<device::Device<Ctx>> for Device<Ctx> {
     }
 }
 
+impl<Ctx: device::DeviceContext> TryFrom<&device::Device<Ctx>> for &Device<Ctx> {
+    type Error = kernel::error::Error;
+
+    fn try_from(dev: &device::Device<Ctx>) -> Result<Self, Self::Error> {
+        // SAFETY: By the type invariant of `Device`, `dev.as_raw()` is a valid pointer to a
+        // `struct device`.
+        if !unsafe { bindings::dev_is_pci(dev.as_raw()) } {
+            return Err(EINVAL);
+        }
+
+        // SAFETY: We've just verified that the bus type of `dev` equals `bindings::pci_bus_type`,
+        // hence `dev` must be embedded in a valid `struct pci_dev` as guaranteed by the
+        // corresponding C code.
+        let pdev = unsafe { container_of!(dev.as_raw(), bindings::pci_dev, dev) };
+
+        // SAFETY: `pdev` is a valid pointer to a `struct pci_dev`.
+        Ok(unsafe { &*pdev.cast() })
+    }
+}
+
 // SAFETY: A `Device` is always reference-counted and can be released from any thread.
 unsafe impl Send for Device {}