1/*
2 * Copyright (c) 2016 RISC-V Foundation
3 * Copyright (c) 2016 The University of Virginia
4 * Copyright (c) 2018 TU Dresden
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions are
9 * met: redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer;
11 * redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution;
14 * neither the name of the copyright holders nor the names of its
15 * contributors may be used to endorse or promote products derived from
16 * this software without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
21 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
22 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
23 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
24 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
28 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 *
30 * Authors: Alec Roelke
31 * Robert Scheffel
32 */
33
34#ifndef __ARCH_RISCV_FAULTS_HH__
35#define __ARCH_RISCV_FAULTS_HH__
36
37#include <string>
38
39#include "arch/riscv/isa.hh"
40#include "arch/riscv/registers.hh"
41#include "cpu/thread_context.hh"
42#include "sim/faults.hh"
43
44namespace RiscvISA
45{
46
47enum FloatException : MiscReg {
48 FloatInexact = 0x1,
49 FloatUnderflow = 0x2,
50 FloatOverflow = 0x4,
51 FloatDivZero = 0x8,
52 FloatInvalid = 0x10
53};
54
55/*
56 * In RISC-V, exception and interrupt codes share some values. They can be
57 * differentiated by an 'Interrupt' flag that is enabled for interrupt faults
58 * but not exceptions. The full fault cause can be computed by placing the
59 * exception (or interrupt) code in the least significant bits of the CAUSE
60 * CSR and then setting the highest bit of CAUSE with the 'Interrupt' flag.
61 * For more details on exception causes, see Chapter 3.1.20 of the RISC-V
62 * privileged specification v 1.10. Codes are enumerated in Table 3.6.
63 */
64enum ExceptionCode : MiscReg {
65 INST_ADDR_MISALIGNED = 0,
66 INST_ACCESS = 1,
67 INST_ILLEGAL = 2,
68 BREAKPOINT = 3,
69 LOAD_ADDR_MISALIGNED = 4,
70 LOAD_ACCESS = 5,
71 STORE_ADDR_MISALIGNED = 6,
72 AMO_ADDR_MISALIGNED = 6,
73 STORE_ACCESS = 7,
74 AMO_ACCESS = 7,
75 ECALL_USER = 8,
76 ECALL_SUPER = 9,
77 ECALL_MACHINE = 11,
78 INST_PAGE = 12,
79 LOAD_PAGE = 13,
80 STORE_PAGE = 15,
81 AMO_PAGE = 15,
82
83 INT_SOFTWARE_USER = 0,
84 INT_SOFTWARE_SUPER = 1,
85 INT_SOFTWARE_MACHINE = 3,
86 INT_TIMER_USER = 4,
87 INT_TIMER_SUPER = 5,
88 INT_TIMER_MACHINE = 7,
89 INT_EXT_USER = 8,
90 INT_EXT_SUPER = 9,
91 INT_EXT_MACHINE = 11,
92 NumInterruptTypes
93};
94
95class RiscvFault : public FaultBase
96{
97 protected:
98 const FaultName _name;
99 const bool _interrupt;
100 ExceptionCode _code;
101
102 RiscvFault(FaultName n, bool i, ExceptionCode c)
103 : _name(n), _interrupt(i), _code(c)
104 {}
105
106 FaultName name() const override { return _name; }
107 bool isInterrupt() const { return _interrupt; }
108 ExceptionCode exception() const { return _code; }
109 virtual MiscReg trap_value() const { return 0; }
110
111 virtual void invokeSE(ThreadContext *tc, const StaticInstPtr &inst);
112 void invoke(ThreadContext *tc, const StaticInstPtr &inst) override;
113};
114
115class Reset : public FaultBase
116{
117 private:
118 const FaultName _name;
119
120 public:
121 Reset() : _name("reset") {}
122 FaultName name() const override { return _name; }
123
124 void invoke(ThreadContext *tc, const StaticInstPtr &inst =
125 StaticInst::nullStaticInstPtr) override;
126};
127
128class InterruptFault : public RiscvFault
129{
130 public:
131 InterruptFault(ExceptionCode c) : RiscvFault("interrupt", true, c) {}
132 InterruptFault(int c) : InterruptFault(static_cast<ExceptionCode>(c)) {}
133};
134
135class InstFault : public RiscvFault
136{
137 protected:
138 const ExtMachInst _inst;
139
140 public:
141 InstFault(FaultName n, const ExtMachInst inst)
142 : RiscvFault(n, false, INST_ILLEGAL), _inst(inst)
143 {}
144
145 MiscReg trap_value() const override { return _inst; }
146};
147
148class UnknownInstFault : public InstFault
149{
150 public:
151 UnknownInstFault(const ExtMachInst inst)
152 : InstFault("Unknown instruction", inst)
153 {}
154
155 void invokeSE(ThreadContext *tc, const StaticInstPtr &inst) override;
156};
157
158class IllegalInstFault : public InstFault
159{
160 private:
161 const std::string reason;
162
163 public:
164 IllegalInstFault(std::string r, const ExtMachInst inst)
165 : InstFault("Illegal instruction", inst)
166 {}
167
168 void invokeSE(ThreadContext *tc, const StaticInstPtr &inst) override;
169};
170
171class UnimplementedFault : public InstFault
172{
173 private:
174 const std::string instName;
175
176 public:
177 UnimplementedFault(std::string name, const ExtMachInst inst)
178 : InstFault("Unimplemented instruction", inst),
179 instName(name)
180 {}
181
182 void invokeSE(ThreadContext *tc, const StaticInstPtr &inst) override;
183};
184
185class IllegalFrmFault: public InstFault
186{
187 private:
188 const uint8_t frm;
189
190 public:
191 IllegalFrmFault(uint8_t r, const ExtMachInst inst)
192 : InstFault("Illegal floating-point rounding mode", inst),
193 frm(r)
194 {}
195
196 void invokeSE(ThreadContext *tc, const StaticInstPtr &inst) override;
197};
198
199class AddressFault : public RiscvFault
200{
201 private:
202 const Addr _addr;
203
204 public:
205 AddressFault(const Addr addr, ExceptionCode code)
206 : RiscvFault("Address", false, code), _addr(addr)
207 {}
208
209 MiscReg trap_value() const override { return _addr; }
210};
211
212class BreakpointFault : public RiscvFault
213{
214 private:
215 const PCState pcState;
216
217 public:
218 BreakpointFault(const PCState &pc)
219 : RiscvFault("Breakpoint", false, BREAKPOINT), pcState(pc)
220 {}
221
222 MiscReg trap_value() const override { return pcState.pc(); }
223 void invokeSE(ThreadContext *tc, const StaticInstPtr &inst) override;
224};
225
226class SyscallFault : public RiscvFault
227{
228 public:
229 SyscallFault(PrivilegeMode prv)
230 : RiscvFault("System call", false, ECALL_USER)
231 {
232 switch (prv) {
233 case PRV_U:
234 _code = ECALL_USER;
235 break;
236 case PRV_S:
237 _code = ECALL_SUPER;
238 break;
239 case PRV_M:
240 _code = ECALL_MACHINE;
241 break;
242 default:
243 panic("Unknown privilege mode %d.", prv);
244 break;
245 }
246 }
247
248 void invokeSE(ThreadContext *tc, const StaticInstPtr &inst) override;
249};
250
251} // namespace RiscvISA
252
253#endif // __ARCH_RISCV_FAULTS_HH__