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