Nouveau - Sep 2025 - [PATCH 2/2] rust: pci: display symbolic PCI vendor names

Hi,

This applies to:

  https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core.git

It's a small follow up to these commits in that same branch:

commit 5e20962a9fc8 ("rust: pci: provide access to PCI Vendor values")
commit ed78a01887e2 ("rust: pci: provide access to PCI Class and
Class-related items")

Danilo, I've added your Suggested-by to these.

John Hubbard (2):
  rust: pci: display symbolic PCI class names
  rust: pci: display symbolic PCI vendor names

 rust/kernel/pci/id.rs | 36 +++++++++++++++++++++++-------------
 1 file changed, 23 insertions(+), 13 deletions(-)


base-commit: d4a5d397c7fb1ca967e0da202cac196e7324f4ea
-- 
2.51.0

The Display implementation for Class was forwarding directly to Debug
printing, resulting in raw hex values instead of PCI Class strings.

Improve things by doing a stringify!() call for each PCI Class item.
This now prints symbolic names such as "DISPLAY_VGA", instead of
"Class(0x030000)". It still falls back to Debug formatting for unknown
class values.

Suggested-by: Danilo Krummrich <dakr at kernel.org>
Signed-off-by: John Hubbard <jhubbard at nvidia.com>
---
 rust/kernel/pci/id.rs | 17 +++++++++++------
 1 file changed, 11 insertions(+), 6 deletions(-)

diff --git a/rust/kernel/pci/id.rs b/rust/kernel/pci/id.rs
index 8ee1dc5c3057..6e081de30faf 100644
--- a/rust/kernel/pci/id.rs
+++ b/rust/kernel/pci/id.rs
@@ -50,6 +50,17 @@ impl Class {
                 pub const $variant: Self =
Self(Self::to_24bit_class($binding));
             )+
         }
+
+        impl fmt::Display for Class {
+            fn fmt(&self, f: &mut fmt::Formatter<'_>) ->
fmt::Result {
+                match self {
+                    $(
+                        &Self::$variant => write!(f,
stringify!($variant)),
+                    )+
+                    _ => <Self as fmt::Debug>::fmt(self, f),
+                }
+            }
+        }
     };
 }
 
@@ -87,12 +98,6 @@ fn fmt(&self, f: &mut fmt::Formatter<'_>)
-> fmt::Result {
     }
 }
 
-impl fmt::Display for Class {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) ->
fmt::Result {
-        <Self as fmt::Debug>::fmt(self, f)
-    }
-}
-
 impl ClassMask {
     /// Get the raw mask value.
     #[inline]
-- 
2.51.0

The Display implementation for Vendor was forwarding directly to Debug
printing, resulting in raw hex values instead of PCI Vendor strings.

Improve things by doing a stringify!() call for each PCI Vendor item.
This now prints symbolic names such as "NVIDIA", instead of
"Vendor(0x10de)". It still falls back to Debug formatting for unknown
class values.

Suggested-by: Danilo Krummrich <dakr at kernel.org>
Signed-off-by: John Hubbard <jhubbard at nvidia.com>
---
 rust/kernel/pci/id.rs | 19 ++++++++++++-------
 1 file changed, 12 insertions(+), 7 deletions(-)

diff --git a/rust/kernel/pci/id.rs b/rust/kernel/pci/id.rs
index 6e081de30faf..63db4d5f5617 100644
--- a/rust/kernel/pci/id.rs
+++ b/rust/kernel/pci/id.rs
@@ -135,6 +135,18 @@ impl Vendor {
                 pub const $variant: Self = Self($binding as u16);
             )+
         }
+
+        impl fmt::Display for Vendor {
+            #[inline]
+            fn fmt(&self, f: &mut fmt::Formatter<'_>) ->
fmt::Result {
+                match self {
+                    $(
+                        &Self::$variant => write!(f,
stringify!($variant)),
+                    )+
+                    _ => <Self as fmt::Debug>::fmt(self, f),
+                }
+            }
+        }
     };
 }
 
@@ -160,13 +172,6 @@ fn fmt(&self, f: &mut fmt::Formatter<'_>)
-> fmt::Result {
     }
 }
 
-impl fmt::Display for Vendor {
-    #[inline]
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) ->
fmt::Result {
-        <Self as fmt::Debug>::fmt(self, f)
-    }
-}
-
 define_all_pci_classes! {
     NOT_DEFINED                = bindings::PCI_CLASS_NOT_DEFINED,              
// 0x000000
     NOT_DEFINED_VGA            = bindings::PCI_CLASS_NOT_DEFINED_VGA,          
// 0x000100
-- 
2.51.0

On Thu Sep 25, 2025 at 10:33 AM JST, John Hubbard wrote:
> Hi,
>
> This applies to:
>
>   https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core.git
>
> It's a small follow up to these commits in that same branch:
>
> commit 5e20962a9fc8 ("rust: pci: provide access to PCI Vendor
values")
> commit ed78a01887e2 ("rust: pci: provide access to PCI Class and
Class-related items")
>
> Danilo, I've added your Suggested-by to these.
>
> John Hubbard (2):
>   rust: pci: display symbolic PCI class names
>   rust: pci: display symbolic PCI vendor names
>
>  rust/kernel/pci/id.rs | 36 +++++++++++++++++++++++-------------
>  1 file changed, 23 insertions(+), 13 deletions(-)
The series,

Reviewed-by: Alexandre Courbot <acourbot at nvidia.com>

On Thu Sep 25, 2025 at 3:33 AM CEST, John Hubbard wrote:
> This applies to:
>
>   https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core.git
This is an old tree, the new one is:

https://git.kernel.org/pub/scm/linux/kernel/git/driver-core/driver-core.git/
> John Hubbard (2):
Applied to driver-core-testing, thanks!
>   rust: pci: display symbolic PCI class names
>   rust: pci: display symbolic PCI vendor names
    [ Remove #[inline] for Vendor::fmt(). - Danilo ]