1/*
2 * Copyright (c) 1997, 2019, 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 *
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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.
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23 */
24
25#ifndef SHARE_RUNTIME_ICACHE_HPP
26#define SHARE_RUNTIME_ICACHE_HPP
27
28#include "memory/allocation.hpp"
29#include "runtime/stubCodeGenerator.hpp"
30#include "utilities/macros.hpp"
31
32// Interface for updating the instruction cache. Whenever the VM modifies
33// code, part of the processor instruction cache potentially has to be flushed.
34
35// Default implementation is in icache.cpp, and can be hidden per-platform.
36// Most platforms must provide only ICacheStubGenerator::generate_icache_flush().
37// Platforms that don't require icache flushing can just nullify the public
38// members of AbstractICache in their ICache class. AbstractICache should never
39// be referenced other than by deriving the ICache class from it.
40//
41// The code for the ICache class and for generate_icache_flush() must be in
42// architecture-specific files, i.e., icache_<arch>.hpp/.cpp
43
44class AbstractICache : AllStatic {
45 public:
46 // The flush stub signature
47 typedef int (*flush_icache_stub_t)(address addr, int lines, int magic);
48
49 protected:
50 // The flush stub function address
51 static flush_icache_stub_t _flush_icache_stub;
52
53 // Call the flush stub
54 static void call_flush_stub(address start, int lines);
55
56 public:
57 enum {
58 stub_size = 0, // Size of the icache flush stub in bytes
59 line_size = 0, // Icache line size in bytes
60 log2_line_size = 0 // log2(line_size)
61 };
62
63 static void initialize();
64 static void invalidate_word(address addr);
65 static void invalidate_range(address start, int nbytes);
66};
67
68
69// Must be included before the definition of ICacheStubGenerator
70// because ICacheStubGenerator uses ICache definitions.
71
72#include CPU_HEADER(icache)
73
74class ICacheStubGenerator : public StubCodeGenerator {
75 public:
76 ICacheStubGenerator(CodeBuffer *c) : StubCodeGenerator(c) {}
77
78 // Generate the icache flush stub.
79 //
80 // Since we cannot flush the cache when this stub is generated,
81 // it must be generated first, and just to be sure, we do extra
82 // work to allow a check that these instructions got executed.
83 //
84 // The flush stub has three parameters (see flush_icache_stub_t).
85 //
86 // addr - Start address, must be aligned at log2_line_size
87 // lines - Number of line_size icache lines to flush
88 // magic - Magic number copied to result register to make sure
89 // the stub executed properly
90 //
91 // A template for generate_icache_flush is
92 //
93 // #define __ _masm->
94 //
95 // void ICacheStubGenerator::generate_icache_flush(
96 // ICache::flush_icache_stub_t* flush_icache_stub
97 // ) {
98 // StubCodeMark mark(this, "ICache", "flush_icache_stub");
99 //
100 // address start = __ pc();
101 //
102 // // emit flush stub asm code
103 //
104 // // Must be set here so StubCodeMark destructor can call the flush stub.
105 // *flush_icache_stub = (ICache::flush_icache_stub_t)start;
106 // };
107 //
108 // #undef __
109 //
110 // The first use of flush_icache_stub must apply it to itself. The
111 // StubCodeMark destructor in generate_icache_flush will call Assembler::flush,
112 // which in turn will call invalidate_range (see asm/assembler.cpp), which
113 // in turn will call the flush stub *before* generate_icache_flush returns.
114 // The usual method of having generate_icache_flush return the address of the
115 // stub to its caller, which would then, e.g., store that address in
116 // flush_icache_stub, won't work. generate_icache_flush must itself set
117 // flush_icache_stub to the address of the stub it generates before
118 // the StubCodeMark destructor is invoked.
119
120 void generate_icache_flush(ICache::flush_icache_stub_t* flush_icache_stub);
121};
122
123#endif // SHARE_RUNTIME_ICACHE_HPP
124