fix CI

.github/workflows/validate_operations.yml

@@ -9,7 +9,23 @@ on:
   pull_request:
 
 jobs:
+  # Expose env vars as outputs so they can be passed to reusable workflows
+  config:
+    runs-on: ubuntu-latest
+    outputs:
+      llvm-commit: ${{ steps.set-vars.outputs.llvm-commit }}
+    steps:
+      - id: set-vars
+        run: echo "llvm-commit=$LLVM_COMMIT" >> "$GITHUB_OUTPUT"
+
+  build-mlir-cache:
+    needs: config
+    uses: ./.github/workflows/build_mlir_cache.yml
+    with:
+      llvm-commit: ${{ needs.config.outputs.llvm-commit }}
+
   validate:
+    needs: build-mlir-cache
     runs-on: ubuntu-latest
 
     steps:
@@ -27,7 +43,9 @@ jobs:
         id: cache-protobuf
         uses: actions/cache@v4
         with:
-          path: /usr/local
+          path: |
+            /usr/local/lib/libproto*
+            /usr/local/include/google/protobuf
           key: protobuf-${{ runner.os }}-${{ env.PROTOBUF_COMMIT }}
 
       - name: Install protobuf
@@ -57,36 +75,12 @@ jobs:
       - name: Install Python dependencies
         run: pip install numpy onnx colorama
 
-      - name: Cache MLIR build
-        id: cache-mlir
-        uses: actions/cache@v4
+      - name: Restore MLIR cache
+        uses: actions/cache/restore@v4
         with:
           path: onnx-mlir/llvm-project/build
           key: mlir-${{ runner.os }}-${{ env.LLVM_COMMIT }}
-
-      - name: Clone LLVM
-        if: steps.cache-mlir.outputs.cache-hit != 'true'
-        run: |
-          git clone --filter=blob:none --no-checkout https://github.com/llvm/llvm-project.git onnx-mlir/llvm-project
-          cd onnx-mlir/llvm-project
-          git fetch --depth 1 origin ${{ env.LLVM_COMMIT }}
-          git checkout FETCH_HEAD
-
-      - name: Build MLIR
-        if: steps.cache-mlir.outputs.cache-hit != 'true'
-        run: |
-          mkdir -p onnx-mlir/llvm-project/build
-          cd onnx-mlir/llvm-project/build
-          cmake -G Ninja ../llvm \
-            -DLLVM_ENABLE_PROJECTS="mlir;clang" \
-            -DLLVM_ENABLE_RUNTIMES="openmp" \
-            -DLLVM_TARGETS_TO_BUILD="host" \
-            -DCMAKE_BUILD_TYPE=Release \
-            -DLLVM_ENABLE_ASSERTIONS=ON \
-            -DLLVM_ENABLE_RTTI=ON \
-            -DENABLE_LIBOMPTARGET=OFF \
-            -DLLVM_ENABLE_LIBEDIT=OFF
-          cmake --build .
+          fail-on-cache-miss: true
 
       - name: Build Raptor
         run: |