hotspot/src/share/vm/runtime/icache.hpp
changeset 1 489c9b5090e2
child 5547 f4b087cbb361
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/share/vm/runtime/icache.hpp	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,115 @@
+/*
+ * Copyright 1997-2004 Sun Microsystems, Inc.  All Rights Reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ *
+ */
+
+// Interface for updating the instruction cache.  Whenever the VM modifies
+// code, part of the processor instruction cache potentially has to be flushed.
+
+// Default implementation is in icache.cpp, and can be hidden per-platform.
+// Most platforms must provide only ICacheStubGenerator::generate_icache_flush().
+// Platforms that don't require icache flushing can just nullify the public
+// members of AbstractICache in their ICache class.  AbstractICache should never
+// be referenced other than by deriving the ICache class from it.
+//
+// The code for the ICache class and for generate_icache_flush() must be in
+// architecture-specific files, i.e., icache_<arch>.hpp/.cpp
+
+class AbstractICache : AllStatic {
+ public:
+  // The flush stub signature
+  typedef int (*flush_icache_stub_t)(address addr, int lines, int magic);
+
+ protected:
+  // The flush stub function address
+  static flush_icache_stub_t _flush_icache_stub;
+
+  // Call the flush stub
+  static void call_flush_stub(address start, int lines);
+
+ public:
+  enum {
+    stub_size      = 0, // Size of the icache flush stub in bytes
+    line_size      = 0, // Icache line size in bytes
+    log2_line_size = 0  // log2(line_size)
+  };
+
+  static void initialize();
+  static void invalidate_word(address addr);
+  static void invalidate_range(address start, int nbytes);
+};
+
+
+// Must be included before the definition of ICacheStubGenerator
+// because ICacheStubGenerator uses ICache definitions.
+
+#include "incls/_icache_pd.hpp.incl"
+
+
+class ICacheStubGenerator : public StubCodeGenerator {
+ public:
+  ICacheStubGenerator(CodeBuffer *c) : StubCodeGenerator(c) {}
+
+  // Generate the icache flush stub.
+  //
+  // Since we cannot flush the cache when this stub is generated,
+  // it must be generated first, and just to be sure, we do extra
+  // work to allow a check that these instructions got executed.
+  //
+  // The flush stub has three parameters (see flush_icache_stub_t).
+  //
+  //   addr  - Start address, must be aligned at log2_line_size
+  //   lines - Number of line_size icache lines to flush
+  //   magic - Magic number copied to result register to make sure
+  //           the stub executed properly
+  //
+  // A template for generate_icache_flush is
+  //
+  //    #define __ _masm->
+  //
+  //    void ICacheStubGenerator::generate_icache_flush(
+  //      ICache::flush_icache_stub_t* flush_icache_stub
+  //    ) {
+  //      StubCodeMark mark(this, "ICache", "flush_icache_stub");
+  //
+  //      address start = __ pc();
+  //
+  //      // emit flush stub asm code
+  //
+  //      // Must be set here so StubCodeMark destructor can call the flush stub.
+  //      *flush_icache_stub = (ICache::flush_icache_stub_t)start;
+  //    };
+  //
+  //    #undef __
+  //
+  // The first use of flush_icache_stub must apply it to itself.  The
+  // StubCodeMark destructor in generate_icache_flush will call Assembler::flush,
+  // which in turn will call invalidate_range (see asm/assembler.cpp), which
+  // in turn will call the flush stub *before* generate_icache_flush returns.
+  // The usual method of having generate_icache_flush return the address of the
+  // stub to its caller, which would then, e.g., store that address in
+  // flush_icache_stub, won't work.  generate_icache_flush must itself set
+  // flush_icache_stub to the address of the stub it generates before
+  // the StubCodeMark destructor is invoked.
+
+  void generate_icache_flush(ICache::flush_icache_stub_t* flush_icache_stub);
+};