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 2.1 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 "exec/gdbstub.h"
24#include "qemu/host-utils.h"
25#ifndef CONFIG_USER_ONLY
26#include "hw/loader.h"
27#endif
28
29void openrisc_cpu_do_interrupt(CPUState *cs)
30{
31#ifndef CONFIG_USER_ONLY
32 OpenRISCCPU *cpu = OPENRISC_CPU(cs);
33 CPUOpenRISCState *env = &cpu->env;
34 int exception = cs->exception_index;
35
36 env->epcr = env->pc;
37 if (exception == EXCP_SYSCALL) {
38 env->epcr += 4;
39 }
40 /* When we have an illegal instruction the error effective address
41 shall be set to the illegal instruction address. */
42 if (exception == EXCP_ILLEGAL) {
43 env->eear = env->pc;
44 }
45
46 /* During exceptions esr is populared with the pre-exception sr. */
47 env->esr = cpu_get_sr(env);
48 /* In parallel sr is updated to disable mmu, interrupts, timers and
49 set the delay slot exception flag. */
50 env->sr &= ~SR_DME;
51 env->sr &= ~SR_IME;
52 env->sr |= SR_SM;
53 env->sr &= ~SR_IEE;
54 env->sr &= ~SR_TEE;
55 env->pmr &= ~PMR_DME;
56 env->pmr &= ~PMR_SME;
57 env->lock_addr = -1;
58
59 /* Set/clear dsx to indicate if we are in a delay slot exception. */
60 if (env->dflag) {
61 env->dflag = 0;
62 env->sr |= SR_DSX;
63 env->epcr -= 4;
64 } else {
65 env->sr &= ~SR_DSX;
66 }
67
68 if (exception > 0 && exception < EXCP_NR) {
69 static const char * const int_name[EXCP_NR] = {
70 [EXCP_RESET] = "RESET",
71 [EXCP_BUSERR] = "BUSERR (bus error)",
72 [EXCP_DPF] = "DFP (data protection fault)",
73 [EXCP_IPF] = "IPF (code protection fault)",
74 [EXCP_TICK] = "TICK (timer interrupt)",
75 [EXCP_ALIGN] = "ALIGN",
76 [EXCP_ILLEGAL] = "ILLEGAL",
77 [EXCP_INT] = "INT (device interrupt)",
78 [EXCP_DTLBMISS] = "DTLBMISS (data tlb miss)",
79 [EXCP_ITLBMISS] = "ITLBMISS (code tlb miss)",
80 [EXCP_RANGE] = "RANGE",
81 [EXCP_SYSCALL] = "SYSCALL",
82 [EXCP_FPE] = "FPE",
83 [EXCP_TRAP] = "TRAP",
84 };
85
86 qemu_log_mask(CPU_LOG_INT, "INT: %s\n", int_name[exception]);
87
88 hwaddr vect_pc = exception << 8;
89 if (env->cpucfgr & CPUCFGR_EVBARP) {
90 vect_pc |= env->evbar;
91 }
92 if (env->sr & SR_EPH) {
93 vect_pc |= 0xf0000000;
94 }
95 env->pc = vect_pc;
96 } else {
97 cpu_abort(cs, "Unhandled exception 0x%x\n", exception);
98 }
99#endif
100
101 cs->exception_index = -1;
102}
103
104bool openrisc_cpu_exec_interrupt(CPUState *cs, int interrupt_request)
105{
106 OpenRISCCPU *cpu = OPENRISC_CPU(cs);
107 CPUOpenRISCState *env = &cpu->env;
108 int idx = -1;
109
110 if ((interrupt_request & CPU_INTERRUPT_HARD) && (env->sr & SR_IEE)) {
111 idx = EXCP_INT;
112 }
113 if ((interrupt_request & CPU_INTERRUPT_TIMER) && (env->sr & SR_TEE)) {
114 idx = EXCP_TICK;
115 }
116 if (idx >= 0) {
117 cs->exception_index = idx;
118 openrisc_cpu_do_interrupt(cs);
119 return true;
120 }
121 return false;
122}
123