gpu: nova-core: fix layout of NV_PMC_BOOT_0

The layout of NV_PMC_BOOT_0 has two small issues:

- The "chipset" field, while useful to identify a chip, is actually an
  aggregate of two distinct fields named "architecture" and
  "implementation".
- The "architecture" field is split, with its MSB being at a different
  location than the rest of its bits.

Redefine the register layout to match its actual definition as provided
by OpenRM and expose the fully-constructed "architecture" field through
our own "Architecture" type. The "chipset" pseudo-field is also useful
to have, so keep providing it.

Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Link: https://lore.kernel.org/r/20250507-nova-frts-v3-6-fcb02749754d@nvidia.com
[ Use Result from kernel::prelude. - Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>

1 files changed, 16 insertions, 3 deletions

diff --git a/drivers/gpu/nova-core/gpu.rs b/drivers/gpu/nova-core/gpu.rs
index 43139b527fac..059462d7c82b 100644
--- a/drivers/gpu/nova-core/gpu.rs
+++ b/drivers/gpu/nova-core/gpu.rs
@@ -101,9 +101,22 @@ impl fmt::Display for Chipset {
 /// Enum representation of the GPU generation.
 #[derive(fmt::Debug)]
 pub(crate) enum Architecture {
-    Turing,
-    Ampere,
-    Ada,
+    Turing = 0x16,
+    Ampere = 0x17,
+    Ada = 0x19,
+}
+
+impl TryFrom<u8> for Architecture {
+    type Error = Error;
+
+    fn try_from(value: u8) -> Result<Self> {
+        match value {
+            0x16 => Ok(Self::Turing),
+            0x17 => Ok(Self::Ampere),
+            0x19 => Ok(Self::Ada),
+            _ => Err(ENODEV),
+        }
+    }
 }
 
 pub(crate) struct Revision {