text: /*
   * Copyright (c) 1997, 2011, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
   * or visit www.oracle.com if you need additional information or have any
   * questions.
   *
   */
  
  #ifndef SHARE_VM_RUNTIME_ICACHE_HPP
  #define SHARE_VM_RUNTIME_ICACHE_HPP
  
  #include "memory/allocation.hpp"
  #include "runtime/stubCodeGenerator.hpp"
  
  // 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.
  
  #ifdef TARGET_ARCH_x86
  # include "icache_x86.hpp"
  #endif
  #ifdef TARGET_ARCH_sparc
  # include "icache_sparc.hpp"
  #endif
  #ifdef TARGET_ARCH_zero
  # include "icache_zero.hpp"
  #endif
  #ifdef TARGET_ARCH_arm
  # include "icache_arm.hpp"
  #endif
  #ifdef TARGET_ARCH_ppc
  # include "icache_ppc.hpp"
  #endif
  
  
  
  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);
  };
  
  #endif // SHARE_VM_RUNTIME_ICACHE_HPP
  