1 /*
2 * Copyright (c) 2004, 2020, Oracle and/or its affiliates. All rights reserved.
3 * Copyright (c) 2014, 2020, Red Hat Inc. All rights reserved.
4 * Copyright (c) 2020, 2021, Huawei Technologies Co., Ltd. All rights reserved.
5 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
6 *
7 * This code is free software; you can redistribute it and/or modify it
8 * under the terms of the GNU General Public License version 2 only, as
9 * published by the Free Software Foundation.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 *
25 */
26
27 #include "precompiled.hpp"
28 #include "asm/macroAssembler.hpp"
29 #include "gc/shared/barrierSet.hpp"
30 #include "gc/shared/barrierSetAssembler.hpp"
31 #include "memory/resourceArea.hpp"
32 #include "prims/jniFastGetField.hpp"
33 #include "prims/jvm_misc.hpp"
34 #include "prims/jvmtiExport.hpp"
35 #include "runtime/safepoint.hpp"
36
37 #define __ masm->
38
39 #define BUFFER_SIZE 30*wordSize
40
41 // Instead of issuing a LoadLoad barrier we create an address
42 // dependency between loads; this might be more efficient.
43
44 // Common register usage:
45 // x10/f10: result
46 // c_rarg0: jni env
47 // c_rarg1: obj
48 // c_rarg2: jfield id
49
50 static const Register robj = x13;
51 static const Register rcounter = x14;
52 static const Register roffset = x15;
53 static const Register rcounter_addr = x16;
54 static const Register result = x17;
55
56 address JNI_FastGetField::generate_fast_get_int_field0(BasicType type) {
57 const char *name;
58 switch (type) {
59 case T_BOOLEAN: name = "jni_fast_GetBooleanField"; break;
60 case T_BYTE: name = "jni_fast_GetByteField"; break;
61 case T_CHAR: name = "jni_fast_GetCharField"; break;
62 case T_SHORT: name = "jni_fast_GetShortField"; break;
63 case T_INT: name = "jni_fast_GetIntField"; break;
64 case T_LONG: name = "jni_fast_GetLongField"; break;
65 case T_FLOAT: name = "jni_fast_GetFloatField"; break;
66 case T_DOUBLE: name = "jni_fast_GetDoubleField"; break;
67 default: ShouldNotReachHere();
68 name = NULL; // unreachable
69 }
70 ResourceMark rm;
71 BufferBlob* blob = BufferBlob::create(name, BUFFER_SIZE);
72 CodeBuffer cbuf(blob);
73 MacroAssembler* masm = new MacroAssembler(&cbuf);
74 address fast_entry = __ pc();
75
76 Label slow;
77 int32_t offset = 0;
78 __ la_patchable(rcounter_addr, SafepointSynchronize::safepoint_counter_addr(), offset);
79 __ addi(rcounter_addr, rcounter_addr, offset);
80
81 Address safepoint_counter_addr(rcounter_addr, 0);
82 __ lwu(rcounter, safepoint_counter_addr);
83 // An even value means there are no ongoing safepoint operations
84 __ andi(t0, rcounter, 1);
85 __ bnez(t0, slow);
86
87 if (JvmtiExport::can_post_field_access()) {
88 // Using barrier to order wrt. JVMTI check and load of result.
89 __ membar(MacroAssembler::LoadLoad);
90
91 // Check to see if a field access watch has been set before we
92 // take the fast path.
93 int32_t offset2;
94 __ la_patchable(result,
95 ExternalAddress((address) JvmtiExport::get_field_access_count_addr()),
96 offset2);
97 __ lwu(result, Address(result, offset2));
98 __ bnez(result, slow);
99
100 __ mv(robj, c_rarg1);
101 } else {
102 // Using address dependency to order wrt. load of result.
103 __ xorr(robj, c_rarg1, rcounter);
104 __ xorr(robj, robj, rcounter); // obj, since
105 // robj ^ rcounter ^ rcounter == robj
106 // robj is address dependent on rcounter.
107 }
108
109 // Both robj and t0 are clobbered by try_resolve_jobject_in_native.
110 BarrierSetAssembler* bs = BarrierSet::barrier_set()->barrier_set_assembler();
111 assert_cond(bs != NULL);
112 bs->try_resolve_jobject_in_native(masm, c_rarg0, robj, t0, slow);
113
114 __ srli(roffset, c_rarg2, 2); // offset
115
116 assert(count < LIST_CAPACITY, "LIST_CAPACITY too small");
117 speculative_load_pclist[count] = __ pc(); // Used by the segfault handler
118 __ add(roffset, robj, roffset);
119
120 switch (type) {
121 case T_BOOLEAN: __ lbu(result, Address(roffset, 0)); break;
122 case T_BYTE: __ lb(result, Address(roffset, 0)); break;
123 case T_CHAR: __ lhu(result, Address(roffset, 0)); break;
124 case T_SHORT: __ lh(result, Address(roffset, 0)); break;
125 case T_INT: __ lw(result, Address(roffset, 0)); break;
126 case T_LONG: __ ld(result, Address(roffset, 0)); break;
127 case T_FLOAT: {
128 __ flw(f28, Address(roffset, 0)); // f28 as temporaries
129 __ fmv_x_w(result, f28); // f{31--0}-->x
130 break;
131 }
132 case T_DOUBLE: {
133 __ fld(f28, Address(roffset, 0)); // f28 as temporaries
134 __ fmv_x_d(result, f28); // d{63--0}-->x
135 break;
136 }
137 default: ShouldNotReachHere();
138 }
139
140 // Using acquire: Order JVMTI check and load of result wrt. succeeding check
141 // (LoadStore for volatile field).
142 __ membar(MacroAssembler::LoadLoad | MacroAssembler::LoadStore);
143
144 __ lw(t0, safepoint_counter_addr);
145 __ bne(rcounter, t0, slow);
146
147 switch (type) {
148 case T_FLOAT: __ fmv_w_x(f10, result); break;
149 case T_DOUBLE: __ fmv_d_x(f10, result); break;
150 default: __ mv(x10, result); break;
151 }
152 __ ret();
153
154 slowcase_entry_pclist[count++] = __ pc();
155 __ bind(slow);
156 address slow_case_addr;
157 switch (type) {
158 case T_BOOLEAN: slow_case_addr = jni_GetBooleanField_addr(); break;
159 case T_BYTE: slow_case_addr = jni_GetByteField_addr(); break;
160 case T_CHAR: slow_case_addr = jni_GetCharField_addr(); break;
161 case T_SHORT: slow_case_addr = jni_GetShortField_addr(); break;
162 case T_INT: slow_case_addr = jni_GetIntField_addr(); break;
163 case T_LONG: slow_case_addr = jni_GetLongField_addr(); break;
164 case T_FLOAT: slow_case_addr = jni_GetFloatField_addr(); break;
165 case T_DOUBLE: slow_case_addr = jni_GetDoubleField_addr(); break;
166 default: ShouldNotReachHere();
167 slow_case_addr = NULL; // unreachable
168 }
169
170 {
171 __ enter();
172 int32_t tmp_offset = 0;
173 __ la_patchable(t0, ExternalAddress(slow_case_addr), tmp_offset);
174 __ jalr(x1, t0, tmp_offset);
175 __ leave();
176 __ ret();
177 }
178 __ flush();
179
180 return fast_entry;
181 }
182
183
184 address JNI_FastGetField::generate_fast_get_boolean_field() {
185 return generate_fast_get_int_field0(T_BOOLEAN);
186 }
187
188 address JNI_FastGetField::generate_fast_get_byte_field() {
189 return generate_fast_get_int_field0(T_BYTE);
190 }
191
192 address JNI_FastGetField::generate_fast_get_char_field() {
193 return generate_fast_get_int_field0(T_CHAR);
194 }
195
196 address JNI_FastGetField::generate_fast_get_short_field() {
197 return generate_fast_get_int_field0(T_SHORT);
198 }
199
200 address JNI_FastGetField::generate_fast_get_int_field() {
201 return generate_fast_get_int_field0(T_INT);
202 }
203
204 address JNI_FastGetField::generate_fast_get_long_field() {
205 return generate_fast_get_int_field0(T_LONG);
206 }
207
208 address JNI_FastGetField::generate_fast_get_float_field() {
209 return generate_fast_get_int_field0(T_FLOAT);
210 }
211
212 address JNI_FastGetField::generate_fast_get_double_field() {
213 return generate_fast_get_int_field0(T_DOUBLE);
214 }