From 23c6b4eaaeeb9a82992e19eb9ad511da9b8e0b56 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=C3=B6rg=20Thalheim?= <joerg@thalheim.io>
Date: Sun, 5 Mar 2023 10:02:39 +0100
Subject: [PATCH] nixos/hardware/intel: add opencl option

---
 .../manual/configuration/gpu-accel.chapter.md | 15 ++++-----
 nixos/modules/hardware/cpu/intel-opencl.nix   | 31 +++++++++++++++++++
 nixos/modules/module-list.nix                 |  1 +
 3 files changed, 40 insertions(+), 7 deletions(-)
 create mode 100644 nixos/modules/hardware/cpu/intel-opencl.nix

diff --git a/nixos/doc/manual/configuration/gpu-accel.chapter.md b/nixos/doc/manual/configuration/gpu-accel.chapter.md
index 8afa2807b7b60..ff562a24202ef 100644
--- a/nixos/doc/manual/configuration/gpu-accel.chapter.md
+++ b/nixos/doc/manual/configuration/gpu-accel.chapter.md
@@ -70,16 +70,17 @@ are supported by the Intel NEO OpenCL runtime that is provided by the
 intel-compute-runtime package. The proprietary Intel OpenCL runtime, in
 the intel-ocl package, is an alternative for Gen7 GPUs.
 
-The intel-compute-runtime or intel-ocl package can be added to
-[](#opt-hardware.graphics.extraPackages)
-to enable OpenCL support. For example, for Gen8 and later GPUs, the following
-configuration can be used:
+Choose your runtime based on your Intel CPU/GPU generation:
+
+- `intel-compute-runtime`: Since `Broadwell` 5th gen, open source, runs on GPU
+- `intel-ocl`: Since `Ivy Bridge` 3rd gen, closed source, deprecated, runs on CPU
+- `beignet`:  Since `Ivy Bridge` 3rd gen, open source, deprecated, runs on GPU
+
+i.e.
 
 ```nix
 {
-  hardware.graphics.extraPackages = [
-    intel-compute-runtime
-  ];
+  hardware.intel.opencl.runtime = "intel-compute-runtime";
 }
 ```
 
diff --git a/nixos/modules/hardware/cpu/intel-opencl.nix b/nixos/modules/hardware/cpu/intel-opencl.nix
new file mode 100644
index 0000000000000..73cbb70329d56
--- /dev/null
+++ b/nixos/modules/hardware/cpu/intel-opencl.nix
@@ -0,0 +1,31 @@
+{
+  config,
+  lib,
+  pkgs,
+  ...
+}:
+{
+  options.hardware.intel.opencl.runtime = lib.mkOption {
+    type = lib.types.nullOr (
+      lib.types.enum [
+        "intel-compute-runtime"
+        "intel-ocl"
+        "beignet"
+      ]
+    );
+    default = null;
+    description = ''
+      Select the Intel OpenCL runtime to use. Choose your runtime based on your Intel CPU/GPU generation.
+
+      - `intel-compute-runtime`: Since `Broadwell` 5th gen, open source, runs on GPU
+      - `intel-ocl`: Since `Ivy Bridge` 3rd gen, closed source, deprecated, runs on CPU
+      - `beignet`:  Since `Ivy Bridge` 3rd gen, open source, deprecated, runs on GPU
+    '';
+  };
+
+  config = {
+    hardware.opengl.extraPackages = lib.mkIf (config.hardware.intel.opencl.runtime != null) [
+      pkgs.${config.hardware.intel.opencl.runtime}
+    ];
+  };
+}
diff --git a/nixos/modules/module-list.nix b/nixos/modules/module-list.nix
index d412e414f68b5..3adcb714500de 100644
--- a/nixos/modules/module-list.nix
+++ b/nixos/modules/module-list.nix
@@ -56,6 +56,7 @@
   ./hardware/cpu/amd-microcode.nix
   ./hardware/cpu/amd-sev.nix
   ./hardware/cpu/amd-ryzen-smu.nix
+  ./hardware/cpu/intel-opencl.nix
   ./hardware/cpu/intel-microcode.nix
   ./hardware/cpu/intel-sgx.nix
   ./hardware/cpu/x86-msr.nix