xref: /openbmc/qemu/linux-user/alpha/cpu_loop.c (revision a093a655)
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-common.h"
22 #include "qemu.h"
23 #include "user-internals.h"
24 #include "cpu_loop-common.h"
25 #include "signal-common.h"
26 
27 void cpu_loop(CPUAlphaState *env)
28 {
29     CPUState *cs = env_cpu(env);
30     int trapnr;
31     target_siginfo_t info;
32     abi_long sysret;
33 
34     while (1) {
35         bool arch_interrupt = true;
36 
37         cpu_exec_start(cs);
38         trapnr = cpu_exec(cs);
39         cpu_exec_end(cs);
40         process_queued_cpu_work(cs);
41 
42         switch (trapnr) {
43         case EXCP_RESET:
44             fprintf(stderr, "Reset requested. Exit\n");
45             exit(EXIT_FAILURE);
46             break;
47         case EXCP_MCHK:
48             fprintf(stderr, "Machine check exception. Exit\n");
49             exit(EXIT_FAILURE);
50             break;
51         case EXCP_SMP_INTERRUPT:
52         case EXCP_CLK_INTERRUPT:
53         case EXCP_DEV_INTERRUPT:
54             fprintf(stderr, "External interrupt. Exit\n");
55             exit(EXIT_FAILURE);
56             break;
57         case EXCP_MMFAULT:
58             info.si_signo = TARGET_SIGSEGV;
59             info.si_errno = 0;
60             info.si_code = (page_get_flags(env->trap_arg0) & PAGE_VALID
61                             ? TARGET_SEGV_ACCERR : TARGET_SEGV_MAPERR);
62             info._sifields._sigfault._addr = env->trap_arg0;
63             queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
64             break;
65         case EXCP_UNALIGN:
66             info.si_signo = TARGET_SIGBUS;
67             info.si_errno = 0;
68             info.si_code = TARGET_BUS_ADRALN;
69             info._sifields._sigfault._addr = env->trap_arg0;
70             queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
71             break;
72         case EXCP_OPCDEC:
73         do_sigill:
74             info.si_signo = TARGET_SIGILL;
75             info.si_errno = 0;
76             info.si_code = TARGET_ILL_ILLOPC;
77             info._sifields._sigfault._addr = env->pc;
78             queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
79             break;
80         case EXCP_ARITH:
81             info.si_signo = TARGET_SIGFPE;
82             info.si_errno = 0;
83             info.si_code = TARGET_FPE_FLTINV;
84             info._sifields._sigfault._addr = env->pc;
85             queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
86             break;
87         case EXCP_FEN:
88             /* No-op.  Linux simply re-enables the FPU.  */
89             break;
90         case EXCP_CALL_PAL:
91             switch (env->error_code) {
92             case 0x80:
93                 /* BPT */
94                 info.si_signo = TARGET_SIGTRAP;
95                 info.si_errno = 0;
96                 info.si_code = TARGET_TRAP_BRKPT;
97                 info._sifields._sigfault._addr = env->pc;
98                 queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
99                 break;
100             case 0x81:
101                 /* BUGCHK */
102                 info.si_signo = TARGET_SIGTRAP;
103                 info.si_errno = 0;
104                 info.si_code = 0;
105                 info._sifields._sigfault._addr = env->pc;
106                 queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
107                 break;
108             case 0x83:
109                 /* CALLSYS */
110                 trapnr = env->ir[IR_V0];
111                 sysret = do_syscall(env, trapnr,
112                                     env->ir[IR_A0], env->ir[IR_A1],
113                                     env->ir[IR_A2], env->ir[IR_A3],
114                                     env->ir[IR_A4], env->ir[IR_A5],
115                                     0, 0);
116                 if (sysret == -TARGET_ERESTARTSYS) {
117                     env->pc -= 4;
118                     break;
119                 }
120                 if (sysret == -TARGET_QEMU_ESIGRETURN) {
121                     break;
122                 }
123                 /* Syscall writes 0 to V0 to bypass error check, similar
124                    to how this is handled internal to Linux kernel.
125                    (Ab)use trapnr temporarily as boolean indicating error.  */
126                 trapnr = (env->ir[IR_V0] != 0 && sysret < 0);
127                 env->ir[IR_V0] = (trapnr ? -sysret : sysret);
128                 env->ir[IR_A3] = trapnr;
129                 break;
130             case 0x86:
131                 /* IMB */
132                 /* ??? We can probably elide the code using page_unprotect
133                    that is checking for self-modifying code.  Instead we
134                    could simply call tb_flush here.  Until we work out the
135                    changes required to turn off the extra write protection,
136                    this can be a no-op.  */
137                 break;
138             case 0x9E:
139                 /* RDUNIQUE */
140                 /* Handled in the translator for usermode.  */
141                 abort();
142             case 0x9F:
143                 /* WRUNIQUE */
144                 /* Handled in the translator for usermode.  */
145                 abort();
146             case 0xAA:
147                 /* GENTRAP */
148                 info.si_signo = TARGET_SIGFPE;
149                 switch (env->ir[IR_A0]) {
150                 case TARGET_GEN_INTOVF:
151                     info.si_code = TARGET_FPE_INTOVF;
152                     break;
153                 case TARGET_GEN_INTDIV:
154                     info.si_code = TARGET_FPE_INTDIV;
155                     break;
156                 case TARGET_GEN_FLTOVF:
157                     info.si_code = TARGET_FPE_FLTOVF;
158                     break;
159                 case TARGET_GEN_FLTUND:
160                     info.si_code = TARGET_FPE_FLTUND;
161                     break;
162                 case TARGET_GEN_FLTINV:
163                     info.si_code = TARGET_FPE_FLTINV;
164                     break;
165                 case TARGET_GEN_FLTINE:
166                     info.si_code = TARGET_FPE_FLTRES;
167                     break;
168                 case TARGET_GEN_ROPRAND:
169                     info.si_code = 0;
170                     break;
171                 default:
172                     info.si_signo = TARGET_SIGTRAP;
173                     info.si_code = 0;
174                     break;
175                 }
176                 info.si_errno = 0;
177                 info._sifields._sigfault._addr = env->pc;
178                 queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
179                 break;
180             default:
181                 goto do_sigill;
182             }
183             break;
184         case EXCP_DEBUG:
185             info.si_signo = TARGET_SIGTRAP;
186             info.si_errno = 0;
187             info.si_code = TARGET_TRAP_BRKPT;
188             queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
189             break;
190         case EXCP_INTERRUPT:
191             /* Just indicate that signals should be handled asap.  */
192             break;
193         case EXCP_ATOMIC:
194             cpu_exec_step_atomic(cs);
195             arch_interrupt = false;
196             break;
197         default:
198             fprintf(stderr, "Unhandled trap: 0x%x\n", trapnr);
199             cpu_dump_state(cs, stderr, 0);
200             exit(EXIT_FAILURE);
201         }
202         process_pending_signals (env);
203 
204         /* Most of the traps imply a transition through PALcode, which
205            implies an REI instruction has been executed.  Which means
206            that RX and LOCK_ADDR should be cleared.  But there are a
207            few exceptions for traps internal to QEMU.  */
208         if (arch_interrupt) {
209             env->flags &= ~ENV_FLAG_RX_FLAG;
210             env->lock_addr = -1;
211         }
212     }
213 }
214 
215 void target_cpu_copy_regs(CPUArchState *env, struct target_pt_regs *regs)
216 {
217     int i;
218 
219     for(i = 0; i < 28; i++) {
220         env->ir[i] = ((abi_ulong *)regs)[i];
221     }
222     env->ir[IR_SP] = regs->usp;
223     env->pc = regs->pc;
224 }
225