xref: /openbmc/qemu/linux-user/riscv/cpu_loop.c (revision 2038f8c8)
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/error-report.h"
23 #include "qemu.h"
24 #include "cpu_loop-common.h"
25 #include "elf.h"
26 
27 void cpu_loop(CPURISCVState *env)
28 {
29     CPUState *cs = env_cpu(env);
30     int trapnr, signum, sigcode;
31     target_ulong sigaddr;
32     target_ulong ret;
33 
34     for (;;) {
35         cpu_exec_start(cs);
36         trapnr = cpu_exec(cs);
37         cpu_exec_end(cs);
38         process_queued_cpu_work(cs);
39 
40         signum = 0;
41         sigcode = 0;
42         sigaddr = 0;
43 
44         switch (trapnr) {
45         case EXCP_INTERRUPT:
46             /* just indicate that signals should be handled asap */
47             break;
48         case EXCP_ATOMIC:
49             cpu_exec_step_atomic(cs);
50             break;
51         case RISCV_EXCP_U_ECALL:
52             env->pc += 4;
53             if (env->gpr[xA7] == TARGET_NR_arch_specific_syscall + 15) {
54                 /* riscv_flush_icache_syscall is a no-op in QEMU as
55                    self-modifying code is automatically detected */
56                 ret = 0;
57             } else {
58                 ret = do_syscall(env,
59                                  env->gpr[(env->elf_flags & EF_RISCV_RVE)
60                                     ? xT0 : xA7],
61                                  env->gpr[xA0],
62                                  env->gpr[xA1],
63                                  env->gpr[xA2],
64                                  env->gpr[xA3],
65                                  env->gpr[xA4],
66                                  env->gpr[xA5],
67                                  0, 0);
68             }
69             if (ret == -TARGET_ERESTARTSYS) {
70                 env->pc -= 4;
71             } else if (ret != -TARGET_QEMU_ESIGRETURN) {
72                 env->gpr[xA0] = ret;
73             }
74             if (cs->singlestep_enabled) {
75                 goto gdbstep;
76             }
77             break;
78         case RISCV_EXCP_ILLEGAL_INST:
79             signum = TARGET_SIGILL;
80             sigcode = TARGET_ILL_ILLOPC;
81             break;
82         case RISCV_EXCP_BREAKPOINT:
83             signum = TARGET_SIGTRAP;
84             sigcode = TARGET_TRAP_BRKPT;
85             sigaddr = env->pc;
86             break;
87         case RISCV_EXCP_INST_PAGE_FAULT:
88         case RISCV_EXCP_LOAD_PAGE_FAULT:
89         case RISCV_EXCP_STORE_PAGE_FAULT:
90             signum = TARGET_SIGSEGV;
91             sigcode = TARGET_SEGV_MAPERR;
92             break;
93         case EXCP_DEBUG:
94         gdbstep:
95             signum = TARGET_SIGTRAP;
96             sigcode = TARGET_TRAP_BRKPT;
97             break;
98         default:
99             EXCP_DUMP(env, "\nqemu: unhandled CPU exception %#x - aborting\n",
100                      trapnr);
101             exit(EXIT_FAILURE);
102         }
103 
104         if (signum) {
105             target_siginfo_t info = {
106                 .si_signo = signum,
107                 .si_errno = 0,
108                 .si_code = sigcode,
109                 ._sifields._sigfault._addr = sigaddr
110             };
111             queue_signal(env, info.si_signo, QEMU_SI_KILL, &info);
112         }
113 
114         process_pending_signals(env);
115     }
116 }
117 
118 void target_cpu_copy_regs(CPUArchState *env, struct target_pt_regs *regs)
119 {
120     CPUState *cpu = env_cpu(env);
121     TaskState *ts = cpu->opaque;
122     struct image_info *info = ts->info;
123 
124     env->pc = regs->sepc;
125     env->gpr[xSP] = regs->sp;
126     env->elf_flags = info->elf_flags;
127 
128     if ((env->misa & RVE) && !(env->elf_flags & EF_RISCV_RVE)) {
129         error_report("Incompatible ELF: RVE cpu requires RVE ABI binary");
130         exit(EXIT_FAILURE);
131     }
132 }
133