1 /* 2 * Copyright (c) 1997, 2010, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 #include "precompiled.hpp" 26 #include "memory/resourceArea.hpp" 27 #include "runtime/icache.hpp" 28 29 // The flush stub function address 30 AbstractICache::flush_icache_stub_t AbstractICache::_flush_icache_stub = NULL; 31 32 void AbstractICache::initialize() { 33 // Making this stub must be FIRST use of assembler 34 ResourceMark rm; 35 36 BufferBlob* b = BufferBlob::create("flush_icache_stub", ICache::stub_size); 37 CodeBuffer c(b); 38 39 ICacheStubGenerator g(&c); 40 g.generate_icache_flush(&_flush_icache_stub); 41 42 // The first use of flush_icache_stub must apply it to itself. 43 // The StubCodeMark destructor in generate_icache_flush will 44 // call Assembler::flush, which in turn will call invalidate_range, 45 // which will in turn call the flush stub. Thus we don't need an 46 // explicit call to invalidate_range here. This assumption is 47 // checked in invalidate_range. 48 } 49 50 void AbstractICache::call_flush_stub(address start, int lines) { 51 // The business with the magic number is just a little security. 52 // We cannot call the flush stub when generating the flush stub 53 // because it isn't there yet. So, the stub also returns its third 54 // parameter. This is a cheap check that the stub was really executed. 55 static int magic = 0xbaadbabe; 56 57 int auto_magic = magic; // Make a local copy to avoid race condition 58 int r = (*_flush_icache_stub)(start, lines, auto_magic); 59 guarantee(r == auto_magic, "flush stub routine did not execute"); 60 ++magic; 61 } 62 63 void AbstractICache::invalidate_word(address addr) { 64 // Because this is called for instruction patching on the fly, long after 65 // bootstrapping, we execute the stub directly. Account for a 4-byte word 66 // spanning two cache lines by computing a start line address by rounding 67 // addr down to a line_size boundary, and an end line address by adding 68 // the word size - 1 and rounding the result down to a line_size boundary. 69 // If we just added word size, we'd mistakenly flush the next cache line 70 // if the word to be flushed started in the last 4 bytes of the line. 71 // Doing that would segv if the next line weren't mapped. 72 73 const int word_size_in_bytes = 4; // Always, regardless of platform 74 75 intptr_t start_line = ((intptr_t)addr + 0) & ~(ICache::line_size - 1); 76 intptr_t end_line = ((intptr_t)addr + word_size_in_bytes - 1) 77 & ~(ICache::line_size - 1); 78 (*_flush_icache_stub)((address)start_line, start_line == end_line ? 1 : 2, 0); 79 } 80 81 void AbstractICache::invalidate_range(address start, int nbytes) { 82 static bool firstTime = true; 83 if (firstTime) { 84 guarantee(start == CAST_FROM_FN_PTR(address, _flush_icache_stub), 85 "first flush should be for flush stub"); 86 firstTime = false; 87 return; 88 } 89 if (nbytes == 0) { 90 return; 91 } 92 // Align start address to an icache line boundary and transform 93 // nbytes to an icache line count. 94 const uint line_offset = mask_address_bits(start, ICache::line_size-1); 95 if (line_offset != 0) { 96 start -= line_offset; 97 nbytes += line_offset; 98 } 99 call_flush_stub(start, round_to(nbytes, ICache::line_size) >> 100 ICache::log2_line_size); 101 } 102 103 // For init.cpp 104 void icache_init() { 105 ICache::initialize(); 106 }