1 /*
2 * Copyright (c) 1997, 2004, 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 // Interface for updating the instruction cache. Whenever the VM modifies
26 // code, part of the processor instruction cache potentially has to be flushed.
27
28 // Default implementation is in icache.cpp, and can be hidden per-platform.
29 // Most platforms must provide only ICacheStubGenerator::generate_icache_flush().
30 // Platforms that don't require icache flushing can just nullify the public
31 // members of AbstractICache in their ICache class. AbstractICache should never
32 // be referenced other than by deriving the ICache class from it.
33 //
34 // The code for the ICache class and for generate_icache_flush() must be in
35 // architecture-specific files, i.e., icache_<arch>.hpp/.cpp
36
37 class AbstractICache : AllStatic {
38 public:
39 // The flush stub signature
40 typedef int (*flush_icache_stub_t)(address addr, int lines, int magic);
41
42 protected:
43 // The flush stub function address
44 static flush_icache_stub_t _flush_icache_stub;
45
46 // Call the flush stub
47 static void call_flush_stub(address start, int lines);
48
49 public:
50 enum {
51 stub_size = 0, // Size of the icache flush stub in bytes
52 line_size = 0, // Icache line size in bytes
53 log2_line_size = 0 // log2(line_size)
54 };
55
56 static void initialize();
57 static void invalidate_word(address addr);
58 static void invalidate_range(address start, int nbytes);
59 };
60
61
62 // Must be included before the definition of ICacheStubGenerator
63 // because ICacheStubGenerator uses ICache definitions.
64
65 #include "incls/_icache_pd.hpp.incl"
66
67
68 class ICacheStubGenerator : public StubCodeGenerator {
69 public:
70 ICacheStubGenerator(CodeBuffer *c) : StubCodeGenerator(c) {}
71
72 // Generate the icache flush stub.
73 //
74 // Since we cannot flush the cache when this stub is generated,
75 // it must be generated first, and just to be sure, we do extra
76 // work to allow a check that these instructions got executed.
77 //
78 // The flush stub has three parameters (see flush_icache_stub_t).
79 //
80 // addr - Start address, must be aligned at log2_line_size
81 // lines - Number of line_size icache lines to flush
82 // magic - Magic number copied to result register to make sure
83 // the stub executed properly
84 //
85 // A template for generate_icache_flush is
86 //
87 // #define __ _masm->
88 //
89 // void ICacheStubGenerator::generate_icache_flush(
90 // ICache::flush_icache_stub_t* flush_icache_stub
91 // ) {
92 // StubCodeMark mark(this, "ICache", "flush_icache_stub");
93 //
94 // address start = __ pc();
95 //
96 // // emit flush stub asm code
97 //
98 // // Must be set here so StubCodeMark destructor can call the flush stub.
99 // *flush_icache_stub = (ICache::flush_icache_stub_t)start;
100 // };
101 //
102 // #undef __
103 //
104 // The first use of flush_icache_stub must apply it to itself. The
105 // StubCodeMark destructor in generate_icache_flush will call Assembler::flush,
106 // which in turn will call invalidate_range (see asm/assembler.cpp), which
107 // in turn will call the flush stub *before* generate_icache_flush returns.
108 // The usual method of having generate_icache_flush return the address of the
109 // stub to its caller, which would then, e.g., store that address in
110 // flush_icache_stub, won't work. generate_icache_flush must itself set
111 // flush_icache_stub to the address of the stub it generates before
112 // the StubCodeMark destructor is invoked.
113
114 void generate_icache_flush(ICache::flush_icache_stub_t* flush_icache_stub);
115 };