src/hotspot/cpu/aarch64/stubGenerator_aarch64.cpp

@@ -2363,10 +2363,48 @@
     __ leave();
     __ ret(lr);
     return start;
   }
 
+  address generate_data_cache_writeback() {
+    const Register line        = c_rarg0;  // address of line to write back
+
+    __ align(CodeEntryAlignment);
+
+    StubCodeMark mark(this, "StubRoutines", "_data_cache_writeback");
+
+    address start = __ pc();
+    __ enter();
+    __ cache_wb(Address(line, 0));
+    __ leave();
+    __ ret(lr);
+
+    return start;
+  }
+
+  address generate_data_cache_writeback_sync() {
+    const Register is_pre     = c_rarg0;  // pre or post sync
+
+    __ align(CodeEntryAlignment);
+
+    StubCodeMark mark(this, "StubRoutines", "_data_cache_writeback_sync");
+
+    // pre wbsync is a no-op
+    // post wbsync translates to an sfence
+
+    Label skip;
+    address start = __ pc();
+    __ enter();
+    __ cbnz(is_pre, skip);
+    __ cache_wbsync(false);
+    __ bind(skip);
+    __ leave();
+    __ ret(lr);
+
+    return start;
+  }
+
   void generate_arraycopy_stubs() {
     address entry;
     address entry_jbyte_arraycopy;
     address entry_jshort_arraycopy;
     address entry_jint_arraycopy;

@@ -5822,10 +5860,14 @@
     // generate GHASH intrinsics code
     if (UseGHASHIntrinsics) {
       StubRoutines::_ghash_processBlocks = generate_ghash_processBlocks();
     }
 
+    // data cache line writeback
+    StubRoutines::_data_cache_writeback = generate_data_cache_writeback();
+    StubRoutines::_data_cache_writeback_sync = generate_data_cache_writeback_sync();
+    
     if (UseAESIntrinsics) {
       StubRoutines::_aescrypt_encryptBlock = generate_aescrypt_encryptBlock();
       StubRoutines::_aescrypt_decryptBlock = generate_aescrypt_decryptBlock();
       StubRoutines::_cipherBlockChaining_encryptAESCrypt = generate_cipherBlockChaining_encryptAESCrypt();
       StubRoutines::_cipherBlockChaining_decryptAESCrypt = generate_cipherBlockChaining_decryptAESCrypt();