xref: /openbmc/qemu/linux-user/alpha/cpu_loop.c (revision 7c08eefc)
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 "user-internals.h"
23 #include "cpu_loop-common.h"
24 #include "signal-common.h"
25 
26 void cpu_loop(CPUAlphaState *env)
27 {
28     CPUState *cs = env_cpu(env);
29     int trapnr, si_code;
30     abi_long sysret;
31 
32     while (1) {
33         bool arch_interrupt = true;
34 
35         cpu_exec_start(cs);
36         trapnr = cpu_exec(cs);
37         cpu_exec_end(cs);
38         process_queued_cpu_work(cs);
39 
40         switch (trapnr) {
41         case EXCP_RESET:
42             fprintf(stderr, "Reset requested. Exit\n");
43             exit(EXIT_FAILURE);
44             break;
45         case EXCP_MCHK:
46             fprintf(stderr, "Machine check exception. Exit\n");
47             exit(EXIT_FAILURE);
48             break;
49         case EXCP_SMP_INTERRUPT:
50         case EXCP_CLK_INTERRUPT:
51         case EXCP_DEV_INTERRUPT:
52             fprintf(stderr, "External interrupt. Exit\n");
53             exit(EXIT_FAILURE);
54             break;
55         case EXCP_OPCDEC:
56         do_sigill:
57             force_sig_fault(TARGET_SIGILL, TARGET_ILL_ILLOPC, env->pc);
58             break;
59         case EXCP_ARITH:
60             force_sig_fault(TARGET_SIGFPE, TARGET_FPE_FLTINV, env->pc);
61             break;
62         case EXCP_FEN:
63             /* No-op.  Linux simply re-enables the FPU.  */
64             break;
65         case EXCP_CALL_PAL:
66             switch (env->error_code) {
67             case 0x80:
68                 /* BPT */
69                 goto do_sigtrap_brkpt;
70             case 0x81:
71                 /* BUGCHK */
72                 goto do_sigtrap_unk;
73             case 0x83:
74                 /* CALLSYS */
75                 trapnr = env->ir[IR_V0];
76                 sysret = do_syscall(env, trapnr,
77                                     env->ir[IR_A0], env->ir[IR_A1],
78                                     env->ir[IR_A2], env->ir[IR_A3],
79                                     env->ir[IR_A4], env->ir[IR_A5],
80                                     0, 0);
81                 if (sysret == -QEMU_ERESTARTSYS) {
82                     env->pc -= 4;
83                     break;
84                 }
85                 if (sysret == -QEMU_ESIGRETURN) {
86                     break;
87                 }
88                 /* Syscall writes 0 to V0 to bypass error check, similar
89                    to how this is handled internal to Linux kernel.
90                    (Ab)use trapnr temporarily as boolean indicating error.  */
91                 trapnr = (env->ir[IR_V0] != 0 && sysret < 0);
92                 env->ir[IR_V0] = (trapnr ? -sysret : sysret);
93                 env->ir[IR_A3] = trapnr;
94                 break;
95             case 0x86:
96                 /* IMB */
97                 /* ??? We can probably elide the code using page_unprotect
98                    that is checking for self-modifying code.  Instead we
99                    could simply call tb_flush here.  Until we work out the
100                    changes required to turn off the extra write protection,
101                    this can be a no-op.  */
102                 break;
103             case 0x9E:
104                 /* RDUNIQUE */
105                 /* Handled in the translator for usermode.  */
106                 abort();
107             case 0x9F:
108                 /* WRUNIQUE */
109                 /* Handled in the translator for usermode.  */
110                 abort();
111             case 0xAA:
112                 /* GENTRAP */
113                 switch (env->ir[IR_A0]) {
114                 case TARGET_GEN_INTOVF:
115                     si_code = TARGET_FPE_INTOVF;
116                     break;
117                 case TARGET_GEN_INTDIV:
118                     si_code = TARGET_FPE_INTDIV;
119                     break;
120                 case TARGET_GEN_FLTOVF:
121                     si_code = TARGET_FPE_FLTOVF;
122                     break;
123                 case TARGET_GEN_FLTUND:
124                     si_code = TARGET_FPE_FLTUND;
125                     break;
126                 case TARGET_GEN_FLTINV:
127                     si_code = TARGET_FPE_FLTINV;
128                     break;
129                 case TARGET_GEN_FLTINE:
130                     si_code = TARGET_FPE_FLTRES;
131                     break;
132                 case TARGET_GEN_ROPRAND:
133                     si_code = TARGET_FPE_FLTUNK;
134                     break;
135                 default:
136                     goto do_sigtrap_unk;
137                 }
138                 force_sig_fault(TARGET_SIGFPE, si_code, env->pc);
139                 break;
140             default:
141                 goto do_sigill;
142             }
143             break;
144         case EXCP_DEBUG:
145         do_sigtrap_brkpt:
146             force_sig_fault(TARGET_SIGTRAP, TARGET_TRAP_BRKPT, env->pc);
147             break;
148         do_sigtrap_unk:
149             force_sig_fault(TARGET_SIGTRAP, TARGET_TRAP_UNK, env->pc);
150             break;
151         case EXCP_INTERRUPT:
152             /* Just indicate that signals should be handled asap.  */
153             break;
154         case EXCP_ATOMIC:
155             cpu_exec_step_atomic(cs);
156             arch_interrupt = false;
157             break;
158         default:
159             fprintf(stderr, "Unhandled trap: 0x%x\n", trapnr);
160             cpu_dump_state(cs, stderr, 0);
161             exit(EXIT_FAILURE);
162         }
163         process_pending_signals (env);
164 
165         /* Most of the traps imply a transition through PALcode, which
166            implies an REI instruction has been executed.  Which means
167            that RX and LOCK_ADDR should be cleared.  But there are a
168            few exceptions for traps internal to QEMU.  */
169         if (arch_interrupt) {
170             env->flags &= ~ENV_FLAG_RX_FLAG;
171             env->lock_addr = -1;
172         }
173     }
174 }
175 
176 void target_cpu_copy_regs(CPUArchState *env, struct target_pt_regs *regs)
177 {
178     int i;
179 
180     for(i = 0; i < 28; i++) {
181         env->ir[i] = ((abi_ulong *)regs)[i];
182     }
183     env->ir[IR_SP] = regs->usp;
184     env->pc = regs->pc;
185 }
186