Add linux-loongarch64 CI leg

eng/Subsets.props

@@ -121,9 +121,10 @@
 
   <PropertyGroup>
     <!-- CLR NativeAot only builds in a subset of the matrix -->
+    <_IsCommunityCrossArchitecture Condition="'$(CrossBuild)' == 'true' and ('$(TargetArchitecture)' == 'loongarch64' or '$(TargetArchitecture)' == 'riscv64')">true</_IsCommunityCrossArchitecture>
     <_NativeAotSupportedOS Condition="'$(TargetOS)' == 'windows' or '$(TargetOS)' == 'linux' or '$(TargetOS)' == 'osx' or '$(TargetOS)' == 'maccatalyst' or '$(TargetOS)' == 'iossimulator' or '$(TargetOS)' == 'ios' or '$(TargetOS)' == 'tvossimulator' or '$(TargetOS)' == 'tvos' or '$(TargetOS)' == 'freebsd'">true</_NativeAotSupportedOS>
     <_NativeAotSupportedArch Condition="'$(TargetArchitecture)' == 'x64' or '$(TargetArchitecture)' == 'arm64' or '$(TargetArchitecture)' == 'arm' or '$(TargetArchitecture)' == 'loongarch64' or ('$(TargetOS)' == 'windows' and '$(TargetArchitecture)' == 'x86')">true</_NativeAotSupportedArch>
-    <NativeAotSupported Condition="'$(_NativeAotSupportedOS)' == 'true' and '$(_NativeAotSupportedArch)' == 'true'">true</NativeAotSupported>
+    <NativeAotSupported Condition="'$(_NativeAotSupportedOS)' == 'true' and '$(_NativeAotSupportedArch)' == 'true' and '$(_IsCommunityCrossArchitecture)' != 'true'">true</NativeAotSupported>
     <UseNativeAotForComponents Condition="'$(NativeAotSupported)' == 'true' and '$(TargetOS)' == '$(HostOS)' and '$(TargetsLinuxBionic)' != 'true'">true</UseNativeAotForComponents>
 
     <!-- If we're building clr.nativeaotlibs and not building the CLR runtime, compile libraries against NativeAOT CoreLib -->

eng/pipelines/common/platform-matrix.yml

@@ -438,6 +438,27 @@ jobs:
         crossBuild: true
         ${{ insert }}: ${{ parameters.jobParameters }}
 
+# Linux LoongArch64
+
+- ${{ if containsValue(parameters.platforms, 'linux_loongarch64') }}:
+  - template: xplat-setup.yml
+    parameters:
+      jobTemplate: ${{ parameters.jobTemplate }}
+      helixQueuesTemplate: ${{ parameters.helixQueuesTemplate }}
+      variables: ${{ parameters.variables }}
+      osGroup: linux
+      archType: loongarch64
+      targetRid: linux-loongarch64
+      platform: linux_loongarch64
+      shouldContinueOnError: ${{ parameters.shouldContinueOnError }}
+      container: linux_loongarch64
+      jobParameters:
+        runtimeFlavor: ${{ parameters.runtimeFlavor }}
+        buildConfig: ${{ parameters.buildConfig }}
+        helixQueueGroup: ${{ parameters.helixQueueGroup }}
+        crossBuild: true
+        ${{ insert }}: ${{ parameters.jobParameters }}
+
 # WASI WebAssembly
 
 - ${{ if containsValue(parameters.platforms, 'wasi_wasm') }}:

eng/pipelines/common/templates/pipeline-with-resources.yml

@@ -102,6 +102,11 @@ extends:
         env:
           ROOTFS_DIR: /crossrootfs/riscv64
 
+      linux_loongarch64:
+        image: mcr.microsoft.com/dotnet-buildtools/prereqs:azurelinux-3.0-net10.0-cross-loongarch64
+        env:
+          ROOTFS_DIR: /crossrootfs/loongarch64
+
       debian-12-gcc14-amd64:
         image: mcr.microsoft.com/dotnet-buildtools/prereqs:debian-12-gcc14-amd64
 

eng/pipelines/runtime.yml

@@ -478,28 +478,7 @@ extends:
                 eq(variables['isRollingBuild'], true))
 
       #
-      # Build CoreCLR without building test assets
-      #
-      - template: /eng/pipelines/common/platform-matrix.yml
-        parameters:
-          jobTemplate: /eng/pipelines/common/global-build-job.yml
-          helixQueuesTemplate: /eng/pipelines/libraries/helix-queues-setup.yml
-          buildConfig: checked
-          runtimeFlavor: coreclr
-          platforms:
-          - linux_riscv64
-          jobParameters:
-            testScope: innerloop
-            nameSuffix: CoreCLR
-            buildArgs: -s clr.native+clr.tools+clr.corelib+clr.nativecorelib+clr.aot+clr.packages -c $(_BuildConfig)
-            timeoutInMinutes: 120
-            condition: >-
-              or(
-                eq(stageDependencies.EvaluatePaths.evaluate_paths.outputs['SetPathVars_coreclr.containsChange'], true),
-                eq(variables['isRollingBuild'], true))
-
-      #
-      # Build CoreCLR + Libs + Host + Packs
+      # Build CoreCLR + Libs + Host
       #
       - template: /eng/pipelines/common/platform-matrix.yml
         parameters:
@@ -509,10 +488,12 @@ extends:
           runtimeFlavor: coreclr
           platforms:
           - freebsd_x64
+          - linux_riscv64
+          - linux_loongarch64
           jobParameters:
             testScope: innerloop
             nameSuffix: CoreCLR
-            buildArgs: -s clr+libs+host+packs -c $(_BuildConfig) -rc Checked
+            buildArgs: -s clr+libs+host -c $(_BuildConfig) -rc Checked
             timeoutInMinutes: 120
             condition: >-
               or(
@@ -793,7 +774,6 @@ extends:
           runtimeFlavor: mono
           platforms:
           - linux_musl_x64
-          - linux_riscv64
           - osx_x64
           jobParameters:
             testGroup: innerloop

src/coreclr/nativeaot/Runtime/loongarch64/GcProbe.S

@@ -134,8 +134,8 @@ NESTED_ENTRY RhpGcProbeHijack, _TEXT, NoHandler
     jirl  $r0, $ra, 0
 
 LOCAL_LABEL(WaitForGC):
-    lu12i.w  $t3, ((DEFAULT_FRAME_SAVE_FLAGS + PTFF_SAVE_R4 + PTFF_SAVE_R5 + PTFF_THREAD_HIJACK) >> 12) & 0xfffff
-    ori  $t3, $t3, (DEFAULT_FRAME_SAVE_FLAGS + PTFF_SAVE_R4 + PTFF_SAVE_R5 + PTFF_THREAD_HIJACK) & 0xfff
+    lu12i.w  $t3, ((DEFAULT_FRAME_SAVE_FLAGS + PTFF_SAVE_R4 + PTFF_SAVE_R5 + PTFF_THREAD_HIJACK_HI) >> 12) & 0xfffff
+    ori  $t3, $t3, (DEFAULT_FRAME_SAVE_FLAGS + PTFF_SAVE_R4 + PTFF_SAVE_R5 + PTFF_THREAD_HIJACK_HI) & 0xfff
     b  C_FUNC(RhpWaitForGC)
 NESTED_END RhpGcProbeHijack
 

src/coreclr/nativeaot/Runtime/regdisplay.h

@@ -119,6 +119,8 @@ struct REGDISPLAY
     inline PCODE GetIP() { return IP; }
     inline uintptr_t GetSP() { return SP; }
     inline uintptr_t GetFP() { return *pR11; }
+    inline PTR_uintptr_t GetReturnAddressRegisterLocation() { return pLR; }
+
     inline void SetIP(PCODE IP) { this->IP = IP; }
     inline void SetSP(uintptr_t SP) { this->SP = SP; }
 };
@@ -171,6 +173,7 @@ struct REGDISPLAY
     inline PCODE GetIP() { return IP; }
     inline uintptr_t GetSP() { return SP; }
     inline uintptr_t GetFP() { return *pFP; }
+    inline PTR_uintptr_t GetReturnAddressRegisterLocation() { return pLR; }
 
     inline void SetIP(PCODE IP) { this->IP = IP; }
     inline void SetSP(uintptr_t SP) { this->SP = SP; }
@@ -226,6 +229,7 @@ struct REGDISPLAY
     inline PCODE GetIP() { return IP; }
     inline uintptr_t GetSP() { return SP; }
     inline uintptr_t GetFP() { return *pFP; }
+    inline PTR_uintptr_t GetReturnAddressRegisterLocation() { return pRA; }
 
     inline void SetIP(PCODE IP) { this->IP = IP; }
     inline void SetSP(uintptr_t SP) { this->SP = SP; }

src/coreclr/nativeaot/Runtime/unix/PalRedhawkInline.h

@@ -94,16 +94,21 @@ FORCEINLINE int64_t PalInterlockedCompareExchange64(_Inout_ int64_t volatile *pD
     return result;
 }
 
-#if defined(HOST_AMD64) || defined(HOST_ARM64)
+#if defined(HOST_AMD64) || defined(HOST_ARM64) || defined(HOST_LOONGARCH64)
 FORCEINLINE uint8_t PalInterlockedCompareExchange128(_Inout_ int64_t volatile *pDst, int64_t iValueHigh, int64_t iValueLow, int64_t *pComparandAndResult)
 {
     __int128_t iComparand = ((__int128_t)pComparandAndResult[1] << 64) + (uint64_t)pComparandAndResult[0];
+    // TODO-LOONGARCH64: for LoongArch64, it supports 128bits atomic from 3A6000-CPU which is ISA1.1's version.
+    // The LA64's compiler will translate the `__sync_val_compare_and_swap` into calling the libatomic's library interface to emulate
+    // the 128-bit CAS by mutex_lock if the target processor doesn't support the ISA1.1.
+    // But this emulation by libatomic doesn't satisfy requirements here which it must update two adjacent pointers atomically.
+    // this is being discussed in https://github.com/dotnet/runtime/issues/109276.
     __int128_t iResult = __sync_val_compare_and_swap((__int128_t volatile*)pDst, iComparand, ((__int128_t)iValueHigh << 64) + (uint64_t)iValueLow);
     PalInterlockedOperationBarrier();
     pComparandAndResult[0] = (int64_t)iResult; pComparandAndResult[1] = (int64_t)(iResult >> 64);
     return iComparand == iResult;
 }
-#endif // HOST_AMD64
+#endif // HOST_AMD64 || HOST_ARM64 || HOST_LOONGARCH64
 
 #ifdef HOST_64BIT
 

src/coreclr/nativeaot/Runtime/unix/UnixNativeCodeManager.cpp

@@ -1230,43 +1230,23 @@ bool UnixNativeCodeManager::GetReturnAddressHijackInfo(MethodInfo *    pMethodIn
         return false;
     }
 
-#ifndef TARGET_LOONGARCH64
-    PTR_uintptr_t pLR = pRegisterSet->pLR;
+    PTR_uintptr_t oldLocation = pRegisterSet->GetReturnAddressRegisterLocation();
     if (!VirtualUnwind(pMethodInfo, pRegisterSet))
     {
         return false;
     }
 
-    if (pRegisterSet->pLR == pLR)
+    if (pRegisterSet->GetReturnAddressRegisterLocation() == oldLocation)
     {
         // This is the case when we are either:
         //
-        // 1) In a leaf method that does not push LR on stack, OR
-        // 2) In the prolog/epilog of a non-leaf method that has not yet pushed LR on stack
-        //    or has LR already popped off.
+        // 1) In a leaf method that does not push ReturnAddressRegisterLocation on stack, OR
+        // 2) In the prolog/epilog of a non-leaf method that has not yet pushed ReturnAddressRegisterLocation on stack
+        //    or has ReturnAddressRegisterLocation already popped off.
         return false;
     }
 
-    *ppvRetAddrLocation = (PTR_PTR_VOID)pRegisterSet->pLR;
-#elif
-    PTR_uintptr_t pRA = pRegisterSet->pRA;
-    if (!VirtualUnwind(pMethodInfo, pRegisterSet))
-    {
-        return false;
-    }
-
-    if (pRegisterSet->pRA == pRA)
-    {
-        // This is the case when we are either:
-        //
-        // 1) In a leaf method that does not push RA on stack, OR
-        // 2) In the prolog/epilog of a non-leaf method that has not yet pushed RA on stack
-        //    or has RA already popped off.
-        return false;
-    }
-
-    *ppvRetAddrLocation = (PTR_PTR_VOID)pRegisterSet->pRA;
-#endif     // TARGET_LOONGARCH64
+    *ppvRetAddrLocation = (PTR_PTR_VOID)pRegisterSet->GetReturnAddressRegisterLocation();
 
     return true;
 #else

src/coreclr/nativeaot/Runtime/unix/unixasmmacrosloongarch64.inc

@@ -269,6 +269,7 @@ C_FUNC(\Name):
 #define PTFF_SAVE_R4            0x00000800
 #define PTFF_SAVE_R5            0x00001000
 #define PTFF_SAVE_ALL_PRESERVED 0x000001FF // NOTE: r23-r31
+#define PTFF_THREAD_HIJACK_HI   0x00000002 // upper 32 bits of the PTFF_THREAD_HIJACK
 
 #define DEFAULT_FRAME_SAVE_FLAGS (PTFF_SAVE_ALL_PRESERVED + PTFF_SAVE_SP)
 

src/mono/System.Private.CoreLib/System.Private.CoreLib.csproj

@@ -10,7 +10,7 @@
     <!-- Force System.Private.CoreLib.dll into a special IL output directory -->
     <OutputPath>$(RuntimeBinDir)IL/</OutputPath>
     <Configurations>Debug;Release;Checked</Configurations>
-    <Platforms>x64;x86;arm;armv6;arm64;riscv64;s390x;wasm;ppc64le</Platforms>
+    <Platforms>x64;x86;arm;arm64</Platforms>
 
     <EmitCompilerGeneratedFiles>true</EmitCompilerGeneratedFiles>
   </PropertyGroup>
@@ -57,6 +57,9 @@
   <PropertyGroup Condition="'$(Platform)' == 'arm64'">
     <DefineConstants>$(DefineConstants);TARGET_ARM64</DefineConstants>
   </PropertyGroup>
+  <PropertyGroup Condition="'$(Platform)' == 'loongarch64'">
+    <DefineConstants>$(DefineConstants);TARGET_LOONGARCH64</DefineConstants>
+  </PropertyGroup>
   <PropertyGroup Condition="'$(Platform)' == 'riscv64'">
     <DefineConstants>$(DefineConstants);TARGET_RISCV64</DefineConstants>
   </PropertyGroup>