duke@435: /*
twisti@2103:  * Copyright (c) 1997, 2010, Oracle and/or its affiliates. All rights reserved.
duke@435:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
duke@435:  *
duke@435:  * This code is free software; you can redistribute it and/or modify it
duke@435:  * under the terms of the GNU General Public License version 2 only, as
duke@435:  * published by the Free Software Foundation.
duke@435:  *
duke@435:  * This code is distributed in the hope that it will be useful, but WITHOUT
duke@435:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
duke@435:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
duke@435:  * version 2 for more details (a copy is included in the LICENSE file that
duke@435:  * accompanied this code).
duke@435:  *
duke@435:  * You should have received a copy of the GNU General Public License version
duke@435:  * 2 along with this work; if not, write to the Free Software Foundation,
duke@435:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
duke@435:  *
trims@1907:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
trims@1907:  * or visit www.oracle.com if you need additional information or have any
trims@1907:  * questions.
duke@435:  *
duke@435:  */
duke@435: 
stefank@2314: #include "precompiled.hpp"
stefank@2314: #include "memory/resourceArea.hpp"
stefank@2314: #include "runtime/icache.hpp"
duke@435: 
duke@435: // The flush stub function address
duke@435: AbstractICache::flush_icache_stub_t AbstractICache::_flush_icache_stub = NULL;
duke@435: 
duke@435: void AbstractICache::initialize() {
duke@435:   // Making this stub must be FIRST use of assembler
duke@435:   ResourceMark rm;
duke@435: 
duke@435:   BufferBlob* b = BufferBlob::create("flush_icache_stub", ICache::stub_size);
twisti@2103:   CodeBuffer c(b);
duke@435: 
duke@435:   ICacheStubGenerator g(&c);
duke@435:   g.generate_icache_flush(&_flush_icache_stub);
duke@435: 
duke@435:   // The first use of flush_icache_stub must apply it to itself.
duke@435:   // The StubCodeMark destructor in generate_icache_flush will
duke@435:   // call Assembler::flush, which in turn will call invalidate_range,
duke@435:   // which will in turn call the flush stub.  Thus we don't need an
duke@435:   // explicit call to invalidate_range here.  This assumption is
duke@435:   // checked in invalidate_range.
duke@435: }
duke@435: 
duke@435: void AbstractICache::call_flush_stub(address start, int lines) {
duke@435:   // The business with the magic number is just a little security.
duke@435:   // We cannot call the flush stub when generating the flush stub
duke@435:   // because it isn't there yet.  So, the stub also returns its third
duke@435:   // parameter.  This is a cheap check that the stub was really executed.
duke@435:   static int magic = 0xbaadbabe;
duke@435: 
duke@435:   int auto_magic = magic; // Make a local copy to avoid race condition
duke@435:   int r = (*_flush_icache_stub)(start, lines, auto_magic);
duke@435:   guarantee(r == auto_magic, "flush stub routine did not execute");
duke@435:   ++magic;
duke@435: }
duke@435: 
duke@435: void AbstractICache::invalidate_word(address addr) {
duke@435:   // Because this is called for instruction patching on the fly, long after
duke@435:   // bootstrapping, we execute the stub directly.  Account for a 4-byte word
duke@435:   // spanning two cache lines by computing a start line address by rounding
duke@435:   // addr down to a line_size boundary, and an end line address by adding
duke@435:   // the word size - 1 and rounding the result down to a line_size boundary.
duke@435:   // If we just added word size, we'd mistakenly flush the next cache line
duke@435:   // if the word to be flushed started in the last 4 bytes of the line.
duke@435:   // Doing that would segv if the next line weren't mapped.
duke@435: 
duke@435:   const int word_size_in_bytes = 4; // Always, regardless of platform
duke@435: 
duke@435:   intptr_t start_line = ((intptr_t)addr + 0) & ~(ICache::line_size - 1);
duke@435:   intptr_t end_line   = ((intptr_t)addr + word_size_in_bytes - 1)
duke@435:                                              & ~(ICache::line_size - 1);
duke@435:   (*_flush_icache_stub)((address)start_line, start_line == end_line ? 1 : 2, 0);
duke@435: }
duke@435: 
duke@435: void AbstractICache::invalidate_range(address start, int nbytes) {
duke@435:   static bool firstTime = true;
duke@435:   if (firstTime) {
duke@435:     guarantee(start == CAST_FROM_FN_PTR(address, _flush_icache_stub),
duke@435:               "first flush should be for flush stub");
duke@435:     firstTime = false;
duke@435:     return;
duke@435:   }
duke@435:   if (nbytes == 0) {
duke@435:     return;
duke@435:   }
duke@435:   // Align start address to an icache line boundary and transform
duke@435:   // nbytes to an icache line count.
duke@435:   const uint line_offset = mask_address_bits(start, ICache::line_size-1);
duke@435:   if (line_offset != 0) {
duke@435:     start -= line_offset;
duke@435:     nbytes += line_offset;
duke@435:   }
duke@435:   call_flush_stub(start, round_to(nbytes, ICache::line_size) >>
duke@435:                          ICache::log2_line_size);
duke@435: }
duke@435: 
duke@435: // For init.cpp
duke@435: void icache_init() {
duke@435:   ICache::initialize();
duke@435: }