xref: /openbmc/qemu/linux-user/alpha/cpu_loop.c (revision 7851f1a7)
1 /*
2  *  qemu user cpu loop
3  *
4  *  Copyright (c) 2003-2008 Fabrice Bellard
5  *
6  *  This program is free software; you can redistribute it and/or modify
7  *  it under the terms of the GNU General Public License as published by
8  *  the Free Software Foundation; either version 2 of the License, or
9  *  (at your option) any later version.
10  *
11  *  This program is distributed in the hope that it will be useful,
12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  *  GNU General Public License for more details.
15  *
16  *  You should have received a copy of the GNU General Public License
17  *  along with this program; if not, see <http://www.gnu.org/licenses/>.
18  */
19 
20 #include "qemu/osdep.h"
21 #include "qemu.h"
22 #include "cpu_loop-common.h"
23 
24 void cpu_loop(CPUAlphaState *env)
25 {
26     CPUState *cs = CPU(alpha_env_get_cpu(env));
27     int trapnr;
28     target_siginfo_t info;
29     abi_long sysret;
30 
31     while (1) {
32         bool arch_interrupt = true;
33 
34         cpu_exec_start(cs);
35         trapnr = cpu_exec(cs);
36         cpu_exec_end(cs);
37         process_queued_cpu_work(cs);
38 
39         switch (trapnr) {
40         case EXCP_RESET:
41             fprintf(stderr, "Reset requested. Exit\n");
42             exit(EXIT_FAILURE);
43             break;
44         case EXCP_MCHK:
45             fprintf(stderr, "Machine check exception. Exit\n");
46             exit(EXIT_FAILURE);
47             break;
48         case EXCP_SMP_INTERRUPT:
49         case EXCP_CLK_INTERRUPT:
50         case EXCP_DEV_INTERRUPT:
51             fprintf(stderr, "External interrupt. Exit\n");
52             exit(EXIT_FAILURE);
53             break;
54         case EXCP_MMFAULT:
55             info.si_signo = TARGET_SIGSEGV;
56             info.si_errno = 0;
57             info.si_code = (page_get_flags(env->trap_arg0) & PAGE_VALID
58                             ? TARGET_SEGV_ACCERR : TARGET_SEGV_MAPERR);
59             info._sifields._sigfault._addr = env->trap_arg0;
60             queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
61             break;
62         case EXCP_UNALIGN:
63             info.si_signo = TARGET_SIGBUS;
64             info.si_errno = 0;
65             info.si_code = TARGET_BUS_ADRALN;
66             info._sifields._sigfault._addr = env->trap_arg0;
67             queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
68             break;
69         case EXCP_OPCDEC:
70         do_sigill:
71             info.si_signo = TARGET_SIGILL;
72             info.si_errno = 0;
73             info.si_code = TARGET_ILL_ILLOPC;
74             info._sifields._sigfault._addr = env->pc;
75             queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
76             break;
77         case EXCP_ARITH:
78             info.si_signo = TARGET_SIGFPE;
79             info.si_errno = 0;
80             info.si_code = TARGET_FPE_FLTINV;
81             info._sifields._sigfault._addr = env->pc;
82             queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
83             break;
84         case EXCP_FEN:
85             /* No-op.  Linux simply re-enables the FPU.  */
86             break;
87         case EXCP_CALL_PAL:
88             switch (env->error_code) {
89             case 0x80:
90                 /* BPT */
91                 info.si_signo = TARGET_SIGTRAP;
92                 info.si_errno = 0;
93                 info.si_code = TARGET_TRAP_BRKPT;
94                 info._sifields._sigfault._addr = env->pc;
95                 queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
96                 break;
97             case 0x81:
98                 /* BUGCHK */
99                 info.si_signo = TARGET_SIGTRAP;
100                 info.si_errno = 0;
101                 info.si_code = 0;
102                 info._sifields._sigfault._addr = env->pc;
103                 queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
104                 break;
105             case 0x83:
106                 /* CALLSYS */
107                 trapnr = env->ir[IR_V0];
108                 sysret = do_syscall(env, trapnr,
109                                     env->ir[IR_A0], env->ir[IR_A1],
110                                     env->ir[IR_A2], env->ir[IR_A3],
111                                     env->ir[IR_A4], env->ir[IR_A5],
112                                     0, 0);
113                 if (sysret == -TARGET_ERESTARTSYS) {
114                     env->pc -= 4;
115                     break;
116                 }
117                 if (sysret == -TARGET_QEMU_ESIGRETURN) {
118                     break;
119                 }
120                 /* Syscall writes 0 to V0 to bypass error check, similar
121                    to how this is handled internal to Linux kernel.
122                    (Ab)use trapnr temporarily as boolean indicating error.  */
123                 trapnr = (env->ir[IR_V0] != 0 && sysret < 0);
124                 env->ir[IR_V0] = (trapnr ? -sysret : sysret);
125                 env->ir[IR_A3] = trapnr;
126                 break;
127             case 0x86:
128                 /* IMB */
129                 /* ??? We can probably elide the code using page_unprotect
130                    that is checking for self-modifying code.  Instead we
131                    could simply call tb_flush here.  Until we work out the
132                    changes required to turn off the extra write protection,
133                    this can be a no-op.  */
134                 break;
135             case 0x9E:
136                 /* RDUNIQUE */
137                 /* Handled in the translator for usermode.  */
138                 abort();
139             case 0x9F:
140                 /* WRUNIQUE */
141                 /* Handled in the translator for usermode.  */
142                 abort();
143             case 0xAA:
144                 /* GENTRAP */
145                 info.si_signo = TARGET_SIGFPE;
146                 switch (env->ir[IR_A0]) {
147                 case TARGET_GEN_INTOVF:
148                     info.si_code = TARGET_FPE_INTOVF;
149                     break;
150                 case TARGET_GEN_INTDIV:
151                     info.si_code = TARGET_FPE_INTDIV;
152                     break;
153                 case TARGET_GEN_FLTOVF:
154                     info.si_code = TARGET_FPE_FLTOVF;
155                     break;
156                 case TARGET_GEN_FLTUND:
157                     info.si_code = TARGET_FPE_FLTUND;
158                     break;
159                 case TARGET_GEN_FLTINV:
160                     info.si_code = TARGET_FPE_FLTINV;
161                     break;
162                 case TARGET_GEN_FLTINE:
163                     info.si_code = TARGET_FPE_FLTRES;
164                     break;
165                 case TARGET_GEN_ROPRAND:
166                     info.si_code = 0;
167                     break;
168                 default:
169                     info.si_signo = TARGET_SIGTRAP;
170                     info.si_code = 0;
171                     break;
172                 }
173                 info.si_errno = 0;
174                 info._sifields._sigfault._addr = env->pc;
175                 queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
176                 break;
177             default:
178                 goto do_sigill;
179             }
180             break;
181         case EXCP_DEBUG:
182             info.si_signo = gdb_handlesig(cs, TARGET_SIGTRAP);
183             if (info.si_signo) {
184                 info.si_errno = 0;
185                 info.si_code = TARGET_TRAP_BRKPT;
186                 queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
187             } else {
188                 arch_interrupt = false;
189             }
190             break;
191         case EXCP_INTERRUPT:
192             /* Just indicate that signals should be handled asap.  */
193             break;
194         case EXCP_ATOMIC:
195             cpu_exec_step_atomic(cs);
196             arch_interrupt = false;
197             break;
198         default:
199             fprintf(stderr, "Unhandled trap: 0x%x\n", trapnr);
200             cpu_dump_state(cs, stderr, fprintf, 0);
201             exit(EXIT_FAILURE);
202         }
203         process_pending_signals (env);
204 
205         /* Most of the traps imply a transition through PALcode, which
206            implies an REI instruction has been executed.  Which means
207            that RX and LOCK_ADDR should be cleared.  But there are a
208            few exceptions for traps internal to QEMU.  */
209         if (arch_interrupt) {
210             env->flags &= ~ENV_FLAG_RX_FLAG;
211             env->lock_addr = -1;
212         }
213     }
214 }
215 
216 void target_cpu_copy_regs(CPUArchState *env, struct target_pt_regs *regs)
217 {
218     int i;
219 
220     for(i = 0; i < 28; i++) {
221         env->ir[i] = ((abi_ulong *)regs)[i];
222     }
223     env->ir[IR_SP] = regs->usp;
224     env->pc = regs->pc;
225 }
226