xref: /openbmc/qemu/linux-user/alpha/cpu_loop.c (revision b91a0fa7)
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, si_code;
31     abi_long sysret;
32 
33     while (1) {
34         bool arch_interrupt = true;
35 
36         cpu_exec_start(cs);
37         trapnr = cpu_exec(cs);
38         cpu_exec_end(cs);
39         process_queued_cpu_work(cs);
40 
41         switch (trapnr) {
42         case EXCP_RESET:
43             fprintf(stderr, "Reset requested. Exit\n");
44             exit(EXIT_FAILURE);
45             break;
46         case EXCP_MCHK:
47             fprintf(stderr, "Machine check exception. Exit\n");
48             exit(EXIT_FAILURE);
49             break;
50         case EXCP_SMP_INTERRUPT:
51         case EXCP_CLK_INTERRUPT:
52         case EXCP_DEV_INTERRUPT:
53             fprintf(stderr, "External interrupt. Exit\n");
54             exit(EXIT_FAILURE);
55             break;
56         case EXCP_OPCDEC:
57         do_sigill:
58             force_sig_fault(TARGET_SIGILL, TARGET_ILL_ILLOPC, env->pc);
59             break;
60         case EXCP_ARITH:
61             force_sig_fault(TARGET_SIGFPE, TARGET_FPE_FLTINV, env->pc);
62             break;
63         case EXCP_FEN:
64             /* No-op.  Linux simply re-enables the FPU.  */
65             break;
66         case EXCP_CALL_PAL:
67             switch (env->error_code) {
68             case 0x80:
69                 /* BPT */
70                 goto do_sigtrap_brkpt;
71             case 0x81:
72                 /* BUGCHK */
73                 goto do_sigtrap_unk;
74             case 0x83:
75                 /* CALLSYS */
76                 trapnr = env->ir[IR_V0];
77                 sysret = do_syscall(env, trapnr,
78                                     env->ir[IR_A0], env->ir[IR_A1],
79                                     env->ir[IR_A2], env->ir[IR_A3],
80                                     env->ir[IR_A4], env->ir[IR_A5],
81                                     0, 0);
82                 if (sysret == -QEMU_ERESTARTSYS) {
83                     env->pc -= 4;
84                     break;
85                 }
86                 if (sysret == -QEMU_ESIGRETURN) {
87                     break;
88                 }
89                 /* Syscall writes 0 to V0 to bypass error check, similar
90                    to how this is handled internal to Linux kernel.
91                    (Ab)use trapnr temporarily as boolean indicating error.  */
92                 trapnr = (env->ir[IR_V0] != 0 && sysret < 0);
93                 env->ir[IR_V0] = (trapnr ? -sysret : sysret);
94                 env->ir[IR_A3] = trapnr;
95                 break;
96             case 0x86:
97                 /* IMB */
98                 /* ??? We can probably elide the code using page_unprotect
99                    that is checking for self-modifying code.  Instead we
100                    could simply call tb_flush here.  Until we work out the
101                    changes required to turn off the extra write protection,
102                    this can be a no-op.  */
103                 break;
104             case 0x9E:
105                 /* RDUNIQUE */
106                 /* Handled in the translator for usermode.  */
107                 abort();
108             case 0x9F:
109                 /* WRUNIQUE */
110                 /* Handled in the translator for usermode.  */
111                 abort();
112             case 0xAA:
113                 /* GENTRAP */
114                 switch (env->ir[IR_A0]) {
115                 case TARGET_GEN_INTOVF:
116                     si_code = TARGET_FPE_INTOVF;
117                     break;
118                 case TARGET_GEN_INTDIV:
119                     si_code = TARGET_FPE_INTDIV;
120                     break;
121                 case TARGET_GEN_FLTOVF:
122                     si_code = TARGET_FPE_FLTOVF;
123                     break;
124                 case TARGET_GEN_FLTUND:
125                     si_code = TARGET_FPE_FLTUND;
126                     break;
127                 case TARGET_GEN_FLTINV:
128                     si_code = TARGET_FPE_FLTINV;
129                     break;
130                 case TARGET_GEN_FLTINE:
131                     si_code = TARGET_FPE_FLTRES;
132                     break;
133                 case TARGET_GEN_ROPRAND:
134                     si_code = TARGET_FPE_FLTUNK;
135                     break;
136                 default:
137                     goto do_sigtrap_unk;
138                 }
139                 force_sig_fault(TARGET_SIGFPE, si_code, env->pc);
140                 break;
141             default:
142                 goto do_sigill;
143             }
144             break;
145         case EXCP_DEBUG:
146         do_sigtrap_brkpt:
147             force_sig_fault(TARGET_SIGTRAP, TARGET_TRAP_BRKPT, env->pc);
148             break;
149         do_sigtrap_unk:
150             force_sig_fault(TARGET_SIGTRAP, TARGET_TRAP_UNK, env->pc);
151             break;
152         case EXCP_INTERRUPT:
153             /* Just indicate that signals should be handled asap.  */
154             break;
155         case EXCP_ATOMIC:
156             cpu_exec_step_atomic(cs);
157             arch_interrupt = false;
158             break;
159         default:
160             fprintf(stderr, "Unhandled trap: 0x%x\n", trapnr);
161             cpu_dump_state(cs, stderr, 0);
162             exit(EXIT_FAILURE);
163         }
164         process_pending_signals (env);
165 
166         /* Most of the traps imply a transition through PALcode, which
167            implies an REI instruction has been executed.  Which means
168            that RX and LOCK_ADDR should be cleared.  But there are a
169            few exceptions for traps internal to QEMU.  */
170         if (arch_interrupt) {
171             env->flags &= ~ENV_FLAG_RX_FLAG;
172             env->lock_addr = -1;
173         }
174     }
175 }
176 
177 void target_cpu_copy_regs(CPUArchState *env, struct target_pt_regs *regs)
178 {
179     int i;
180 
181     for(i = 0; i < 28; i++) {
182         env->ir[i] = ((abi_ulong *)regs)[i];
183     }
184     env->ir[IR_SP] = regs->usp;
185     env->pc = regs->pc;
186 }
187