xref: /openbmc/qemu/target/openrisc/interrupt.c (revision c2b38b27)
1 /*
2  * OpenRISC interrupt.
3  *
4  * Copyright (c) 2011-2012 Jia Liu <proljc@gmail.com>
5  *
6  * This library is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2 of the License, or (at your option) any later version.
10  *
11  * This library 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 GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
18  */
19 
20 #include "qemu/osdep.h"
21 #include "cpu.h"
22 #include "exec/exec-all.h"
23 #include "qemu-common.h"
24 #include "exec/gdbstub.h"
25 #include "qemu/host-utils.h"
26 #ifndef CONFIG_USER_ONLY
27 #include "hw/loader.h"
28 #endif
29 
30 void openrisc_cpu_do_interrupt(CPUState *cs)
31 {
32 #ifndef CONFIG_USER_ONLY
33     OpenRISCCPU *cpu = OPENRISC_CPU(cs);
34     CPUOpenRISCState *env = &cpu->env;
35 
36     env->epcr = env->pc;
37     if (env->dflag) {
38         env->dflag = 0;
39         env->sr |= SR_DSX;
40         env->epcr -= 4;
41     } else {
42         env->sr &= ~SR_DSX;
43     }
44     if (cs->exception_index == EXCP_SYSCALL) {
45         env->epcr += 4;
46     }
47     /* When we have an illegal instruction the error effective address
48        shall be set to the illegal instruction address.  */
49     if (cs->exception_index == EXCP_ILLEGAL) {
50         env->eear = env->pc;
51     }
52 
53     /* For machine-state changed between user-mode and supervisor mode,
54        we need flush TLB when we enter&exit EXCP.  */
55     tlb_flush(cs);
56 
57     env->esr = cpu_get_sr(env);
58     env->sr &= ~SR_DME;
59     env->sr &= ~SR_IME;
60     env->sr |= SR_SM;
61     env->sr &= ~SR_IEE;
62     env->sr &= ~SR_TEE;
63     env->tlb->cpu_openrisc_map_address_data = &cpu_openrisc_get_phys_nommu;
64     env->tlb->cpu_openrisc_map_address_code = &cpu_openrisc_get_phys_nommu;
65     env->lock_addr = -1;
66 
67     if (cs->exception_index > 0 && cs->exception_index < EXCP_NR) {
68         env->pc = (cs->exception_index << 8);
69     } else {
70         cpu_abort(cs, "Unhandled exception 0x%x\n", cs->exception_index);
71     }
72 #endif
73 
74     cs->exception_index = -1;
75 }
76 
77 bool openrisc_cpu_exec_interrupt(CPUState *cs, int interrupt_request)
78 {
79     OpenRISCCPU *cpu = OPENRISC_CPU(cs);
80     CPUOpenRISCState *env = &cpu->env;
81     int idx = -1;
82 
83     if ((interrupt_request & CPU_INTERRUPT_HARD) && (env->sr & SR_IEE)) {
84         idx = EXCP_INT;
85     }
86     if ((interrupt_request & CPU_INTERRUPT_TIMER) && (env->sr & SR_TEE)) {
87         idx = EXCP_TICK;
88     }
89     if (idx >= 0) {
90         cs->exception_index = idx;
91         openrisc_cpu_do_interrupt(cs);
92         return true;
93     }
94     return false;
95 }
96