1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/src/share/vm/runtime/icache.cpp Wed Apr 27 01:25:04 2016 +0800
1.3 @@ -0,0 +1,106 @@
1.4 +/*
1.5 + * Copyright (c) 1997, 2010, Oracle and/or its affiliates. All rights reserved.
1.6 + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
1.7 + *
1.8 + * This code is free software; you can redistribute it and/or modify it
1.9 + * under the terms of the GNU General Public License version 2 only, as
1.10 + * published by the Free Software Foundation.
1.11 + *
1.12 + * This code is distributed in the hope that it will be useful, but WITHOUT
1.13 + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
1.14 + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
1.15 + * version 2 for more details (a copy is included in the LICENSE file that
1.16 + * accompanied this code).
1.17 + *
1.18 + * You should have received a copy of the GNU General Public License version
1.19 + * 2 along with this work; if not, write to the Free Software Foundation,
1.20 + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
1.21 + *
1.22 + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
1.23 + * or visit www.oracle.com if you need additional information or have any
1.24 + * questions.
1.25 + *
1.26 + */
1.27 +
1.28 +#include "precompiled.hpp"
1.29 +#include "memory/resourceArea.hpp"
1.30 +#include "runtime/icache.hpp"
1.31 +
1.32 +// The flush stub function address
1.33 +AbstractICache::flush_icache_stub_t AbstractICache::_flush_icache_stub = NULL;
1.34 +
1.35 +void AbstractICache::initialize() {
1.36 + // Making this stub must be FIRST use of assembler
1.37 + ResourceMark rm;
1.38 +
1.39 + BufferBlob* b = BufferBlob::create("flush_icache_stub", ICache::stub_size);
1.40 + CodeBuffer c(b);
1.41 +
1.42 + ICacheStubGenerator g(&c);
1.43 + g.generate_icache_flush(&_flush_icache_stub);
1.44 +
1.45 + // The first use of flush_icache_stub must apply it to itself.
1.46 + // The StubCodeMark destructor in generate_icache_flush will
1.47 + // call Assembler::flush, which in turn will call invalidate_range,
1.48 + // which will in turn call the flush stub. Thus we don't need an
1.49 + // explicit call to invalidate_range here. This assumption is
1.50 + // checked in invalidate_range.
1.51 +}
1.52 +
1.53 +void AbstractICache::call_flush_stub(address start, int lines) {
1.54 + // The business with the magic number is just a little security.
1.55 + // We cannot call the flush stub when generating the flush stub
1.56 + // because it isn't there yet. So, the stub also returns its third
1.57 + // parameter. This is a cheap check that the stub was really executed.
1.58 + static int magic = 0xbaadbabe;
1.59 +
1.60 + int auto_magic = magic; // Make a local copy to avoid race condition
1.61 + int r = (*_flush_icache_stub)(start, lines, auto_magic);
1.62 + guarantee(r == auto_magic, "flush stub routine did not execute");
1.63 + ++magic;
1.64 +}
1.65 +
1.66 +void AbstractICache::invalidate_word(address addr) {
1.67 + // Because this is called for instruction patching on the fly, long after
1.68 + // bootstrapping, we execute the stub directly. Account for a 4-byte word
1.69 + // spanning two cache lines by computing a start line address by rounding
1.70 + // addr down to a line_size boundary, and an end line address by adding
1.71 + // the word size - 1 and rounding the result down to a line_size boundary.
1.72 + // If we just added word size, we'd mistakenly flush the next cache line
1.73 + // if the word to be flushed started in the last 4 bytes of the line.
1.74 + // Doing that would segv if the next line weren't mapped.
1.75 +
1.76 + const int word_size_in_bytes = 4; // Always, regardless of platform
1.77 +
1.78 + intptr_t start_line = ((intptr_t)addr + 0) & ~(ICache::line_size - 1);
1.79 + intptr_t end_line = ((intptr_t)addr + word_size_in_bytes - 1)
1.80 + & ~(ICache::line_size - 1);
1.81 + (*_flush_icache_stub)((address)start_line, start_line == end_line ? 1 : 2, 0);
1.82 +}
1.83 +
1.84 +void AbstractICache::invalidate_range(address start, int nbytes) {
1.85 + static bool firstTime = true;
1.86 + if (firstTime) {
1.87 + guarantee(start == CAST_FROM_FN_PTR(address, _flush_icache_stub),
1.88 + "first flush should be for flush stub");
1.89 + firstTime = false;
1.90 + return;
1.91 + }
1.92 + if (nbytes == 0) {
1.93 + return;
1.94 + }
1.95 + // Align start address to an icache line boundary and transform
1.96 + // nbytes to an icache line count.
1.97 + const uint line_offset = mask_address_bits(start, ICache::line_size-1);
1.98 + if (line_offset != 0) {
1.99 + start -= line_offset;
1.100 + nbytes += line_offset;
1.101 + }
1.102 + call_flush_stub(start, round_to(nbytes, ICache::line_size) >>
1.103 + ICache::log2_line_size);
1.104 +}
1.105 +
1.106 +// For init.cpp
1.107 +void icache_init() {
1.108 + ICache::initialize();
1.109 +}
