[PATCH v6 04/13] drm: nova: Add GPU architecture enum to nova-drm UAPI

[Alistair Popple <apopple@nvidia.com>]

The GPU architecture to be exposed to user-space. This adds a public
enum to the userspace headers for each chip architecture. Nova-core can
then use this enum to define its architectures.

This does create a coupling between nova-drm and nova-core whereby
nova-core depends on the values defined by the user-space API for
nova-drm. However this is entirely appropriate as nova-core must be
bound by the UAPI headers as the enum values are read by nova-core and
passed through to user-space.

It also requires a minor change to the bounded_enum! macro to match the
architecture values in an expression context.

Signed-off-by: Alistair Popple <apopple@nvidia.com>

---

Changes since v4:

 - Rewritten for v5 as exposing chip-id was dropped.

Changes since v3:

 - New for v4, split out from "drm: nova: Add GETPARAM parameter to read
   the GPU chipset"
---
 drivers/gpu/nova-core/gpu.rs | 28 +++++++++++++++++-----------
 drivers/gpu/nova-core/num.rs |  2 +-
 include/uapi/drm/nova_drm.h  | 12 ++++++++++++
 3 files changed, 30 insertions(+), 12 deletions(-)

diff --git a/drivers/gpu/nova-core/gpu.rs b/drivers/gpu/nova-core/gpu.rs
index e1ac8ee9ba4d..8726beb4f693 100644
--- a/drivers/gpu/nova-core/gpu.rs
+++ b/drivers/gpu/nova-core/gpu.rs
@@ -10,7 +10,8 @@
     num::Bounded,
     pci,
     prelude::*,
-    sizes::SizeConstants, //
+    sizes::SizeConstants,
+    uapi, //
 };
 
 use crate::{
@@ -36,8 +37,9 @@
 mod regs;
 
 macro_rules! define_chipset {
-    ({ $($variant:ident = $value:expr),* $(,)* }) =>
+    ({ $($variant:ident = $value:literal),* $(,)* }) =>
     {
+        ::kernel::macros::paste!(
         /// Enum representation of the GPU chipset.
         #[derive(fmt::Debug, Copy, Clone, PartialOrd, Ord, PartialEq, Eq)]
         pub(crate) enum Chipset {
@@ -49,7 +51,6 @@ impl Chipset {
                 $( Chipset::$variant, )*
             ];
 
-            ::kernel::macros::paste!(
             /// Returns the name of this chipset, in lowercase.
             ///
             /// # Examples
@@ -65,7 +66,6 @@ pub(crate) const fn name(&self) -> &'static str {
                 )*
                 }
             }
-            );
         }
 
         // TODO[FPRI]: replace with something like derive(FromPrimitive)
@@ -74,11 +74,14 @@ impl TryFrom<u32> for Chipset {
 
             fn try_from(value: u32) -> Result<Self, Self::Error> {
                 match value {
-                    $( $value => Ok(Chipset::$variant), )*
+                    $(
+                        $value => Ok(Chipset::$variant),
+                    )*
                     _ => Err(ENODEV),
                 }
             }
         }
+    );
     }
 }
 
@@ -158,13 +161,16 @@ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
 bounded_enum! {
     /// Enum representation of the GPU generation.
     #[derive(fmt::Debug, Copy, Clone)]
+    #[repr(u32)]
     pub(crate) enum Architecture with TryFrom<Bounded<u32, 6>> {
-        Turing = 0x16,
-        Ampere = 0x17,
-        Hopper = 0x18,
-        Ada = 0x19,
-        BlackwellGB10x = 0x1a,
-        BlackwellGB20x = 0x1b,
+        Turing = uapi::drm_nova_architecture_NOVA_DRM_ARCHITECTURE_TURING,
+        Ampere = uapi::drm_nova_architecture_NOVA_DRM_ARCHITECTURE_AMPERE,
+        Hopper = uapi::drm_nova_architecture_NOVA_DRM_ARCHITECTURE_HOPPER,
+        Ada = uapi::drm_nova_architecture_NOVA_DRM_ARCHITECTURE_ADA,
+        BlackwellGB10x =
+            uapi::drm_nova_architecture_NOVA_DRM_ARCHITECTURE_BLACKWELL_GB10X,
+        BlackwellGB20x =
+            uapi::drm_nova_architecture_NOVA_DRM_ARCHITECTURE_BLACKWELL_GB20X,
     }
 }
 
diff --git a/drivers/gpu/nova-core/num.rs b/drivers/gpu/nova-core/num.rs
index 6eb174d136ab..f4169235bc24 100644
--- a/drivers/gpu/nova-core/num.rs
+++ b/drivers/gpu/nova-core/num.rs
@@ -263,7 +263,7 @@ fn try_from(
             ) -> kernel::error::Result<Self> {
                 match value.get() {
                     $(
-                        $value => Ok($enum_type::$variant),
+                        value if value == $value => Ok($enum_type::$variant),
                     )*
                     _ => Err(kernel::error::code::EINVAL),
                 }
diff --git a/include/uapi/drm/nova_drm.h b/include/uapi/drm/nova_drm.h
index 3ca90ed9d2bb..f0dcbca1908d 100644
--- a/include/uapi/drm/nova_drm.h
+++ b/include/uapi/drm/nova_drm.h
@@ -25,6 +25,18 @@ extern "C" {
  */
 #define NOVA_GETPARAM_VRAM_BAR_SIZE	0x1
 
+/**
+ * enum drm_nova_architecture - GPU architecture identifier
+ */
+enum drm_nova_architecture {
+	NOVA_DRM_ARCHITECTURE_TURING		= 0x16,
+	NOVA_DRM_ARCHITECTURE_AMPERE		= 0x17,
+	NOVA_DRM_ARCHITECTURE_HOPPER		= 0x18,
+	NOVA_DRM_ARCHITECTURE_ADA		= 0x19,
+	NOVA_DRM_ARCHITECTURE_BLACKWELL_GB10X	= 0x1a,
+	NOVA_DRM_ARCHITECTURE_BLACKWELL_GB20X	= 0x1b,
+};
+
 /**
  * struct drm_nova_getparam - query GPU and driver metadata
  */
-- 
2.54.0