xref: /openbmc/qemu/linux-user/riscv/cpu_loop.c (revision b097ba37)
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/error-report.h"
22 #include "qemu.h"
23 #include "cpu_loop-common.h"
24 #include "elf.h"
25 
26 void cpu_loop(CPURISCVState *env)
27 {
28     CPUState *cs = CPU(riscv_env_get_cpu(env));
29     int trapnr, signum, sigcode;
30     target_ulong sigaddr;
31     target_ulong ret;
32 
33     for (;;) {
34         cpu_exec_start(cs);
35         trapnr = cpu_exec(cs);
36         cpu_exec_end(cs);
37         process_queued_cpu_work(cs);
38 
39         signum = 0;
40         sigcode = 0;
41         sigaddr = 0;
42 
43         switch (trapnr) {
44         case EXCP_INTERRUPT:
45             /* just indicate that signals should be handled asap */
46             break;
47         case EXCP_ATOMIC:
48             cpu_exec_step_atomic(cs);
49             break;
50         case RISCV_EXCP_U_ECALL:
51             env->pc += 4;
52             if (env->gpr[xA7] == TARGET_NR_arch_specific_syscall + 15) {
53                 /* riscv_flush_icache_syscall is a no-op in QEMU as
54                    self-modifying code is automatically detected */
55                 ret = 0;
56             } else {
57                 ret = do_syscall(env,
58                                  env->gpr[(env->elf_flags & EF_RISCV_RVE)
59                                     ? xT0 : xA7],
60                                  env->gpr[xA0],
61                                  env->gpr[xA1],
62                                  env->gpr[xA2],
63                                  env->gpr[xA3],
64                                  env->gpr[xA4],
65                                  env->gpr[xA5],
66                                  0, 0);
67             }
68             if (ret == -TARGET_ERESTARTSYS) {
69                 env->pc -= 4;
70             } else if (ret != -TARGET_QEMU_ESIGRETURN) {
71                 env->gpr[xA0] = ret;
72             }
73             if (cs->singlestep_enabled) {
74                 goto gdbstep;
75             }
76             break;
77         case RISCV_EXCP_ILLEGAL_INST:
78             signum = TARGET_SIGILL;
79             sigcode = TARGET_ILL_ILLOPC;
80             break;
81         case RISCV_EXCP_BREAKPOINT:
82             signum = TARGET_SIGTRAP;
83             sigcode = TARGET_TRAP_BRKPT;
84             sigaddr = env->pc;
85             break;
86         case RISCV_EXCP_INST_PAGE_FAULT:
87         case RISCV_EXCP_LOAD_PAGE_FAULT:
88         case RISCV_EXCP_STORE_PAGE_FAULT:
89             signum = TARGET_SIGSEGV;
90             sigcode = TARGET_SEGV_MAPERR;
91             break;
92         case EXCP_DEBUG:
93         gdbstep:
94             signum = TARGET_SIGTRAP;
95             sigcode = TARGET_TRAP_BRKPT;
96             break;
97         default:
98             EXCP_DUMP(env, "\nqemu: unhandled CPU exception %#x - aborting\n",
99                      trapnr);
100             exit(EXIT_FAILURE);
101         }
102 
103         if (signum) {
104             target_siginfo_t info = {
105                 .si_signo = signum,
106                 .si_errno = 0,
107                 .si_code = sigcode,
108                 ._sifields._sigfault._addr = sigaddr
109             };
110             queue_signal(env, info.si_signo, QEMU_SI_KILL, &info);
111         }
112 
113         process_pending_signals(env);
114     }
115 }
116 
117 void target_cpu_copy_regs(CPUArchState *env, struct target_pt_regs *regs)
118 {
119     CPUState *cpu = ENV_GET_CPU(env);
120     TaskState *ts = cpu->opaque;
121     struct image_info *info = ts->info;
122 
123     env->pc = regs->sepc;
124     env->gpr[xSP] = regs->sp;
125     env->elf_flags = info->elf_flags;
126 
127     if ((env->misa & RVE) && !(env->elf_flags & EF_RISCV_RVE)) {
128         error_report("Incompatible ELF: RVE cpu requires RVE ABI binary");
129         exit(EXIT_FAILURE);
130     }
131 }
132