xref: /openbmc/qemu/target/openrisc/interrupt.c (revision d447a624)
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 "exec/exec-all.h"
24 #include "gdbstub/helpers.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     OpenRISCCPU *cpu = OPENRISC_CPU(cs);
33     CPUOpenRISCState *env = &cpu->env;
34     int exception = cs->exception_index;
35 
36     env->epcr = env->pc;
37 
38     /* When we have an illegal instruction the error effective address
39        shall be set to the illegal instruction address.  */
40     if (exception == EXCP_ILLEGAL) {
41         env->eear = env->pc;
42     }
43 
44     /* During exceptions esr is populared with the pre-exception sr.  */
45     env->esr = cpu_get_sr(env);
46     /* In parallel sr is updated to disable mmu, interrupts, timers and
47        set the delay slot exception flag.  */
48     env->sr &= ~SR_DME;
49     env->sr &= ~SR_IME;
50     env->sr |= SR_SM;
51     env->sr &= ~SR_IEE;
52     env->sr &= ~SR_TEE;
53     env->pmr &= ~PMR_DME;
54     env->pmr &= ~PMR_SME;
55     env->lock_addr = -1;
56 
57     /* Set/clear dsx to indicate if we are in a delay slot exception.  */
58     if (env->dflag) {
59         env->dflag = 0;
60         env->sr |= SR_DSX;
61         env->epcr -= 4;
62     } else {
63         env->sr &= ~SR_DSX;
64         if (exception == EXCP_SYSCALL || exception == EXCP_FPE) {
65             env->epcr += 4;
66         }
67     }
68 
69     if (exception > 0 && exception < EXCP_NR) {
70         static const char * const int_name[EXCP_NR] = {
71             [EXCP_RESET]    = "RESET",
72             [EXCP_BUSERR]   = "BUSERR (bus error)",
73             [EXCP_DPF]      = "DFP (data protection fault)",
74             [EXCP_IPF]      = "IPF (code protection fault)",
75             [EXCP_TICK]     = "TICK (timer interrupt)",
76             [EXCP_ALIGN]    = "ALIGN",
77             [EXCP_ILLEGAL]  = "ILLEGAL",
78             [EXCP_INT]      = "INT (device interrupt)",
79             [EXCP_DTLBMISS] = "DTLBMISS (data tlb miss)",
80             [EXCP_ITLBMISS] = "ITLBMISS (code tlb miss)",
81             [EXCP_RANGE]    = "RANGE",
82             [EXCP_SYSCALL]  = "SYSCALL",
83             [EXCP_FPE]      = "FPE",
84             [EXCP_TRAP]     = "TRAP",
85         };
86 
87         qemu_log_mask(CPU_LOG_INT, "CPU: %d INT: %s\n",
88                       cs->cpu_index,
89                       int_name[exception]);
90 
91         hwaddr vect_pc = exception << 8;
92         if (env->cpucfgr & CPUCFGR_EVBARP) {
93             vect_pc |= env->evbar;
94         }
95         if (env->sr & SR_EPH) {
96             vect_pc |= 0xf0000000;
97         }
98         env->pc = vect_pc;
99     } else {
100         cpu_abort(cs, "Unhandled exception 0x%x\n", exception);
101     }
102 
103     cs->exception_index = -1;
104 }
105 
106 bool openrisc_cpu_exec_interrupt(CPUState *cs, int interrupt_request)
107 {
108     OpenRISCCPU *cpu = OPENRISC_CPU(cs);
109     CPUOpenRISCState *env = &cpu->env;
110     int idx = -1;
111 
112     if ((interrupt_request & CPU_INTERRUPT_HARD) && (env->sr & SR_IEE)) {
113         idx = EXCP_INT;
114     }
115     if ((interrupt_request & CPU_INTERRUPT_TIMER) && (env->sr & SR_TEE)) {
116         idx = EXCP_TICK;
117     }
118     if (idx >= 0) {
119         cs->exception_index = idx;
120         openrisc_cpu_do_interrupt(cs);
121         return true;
122     }
123     return false;
124 }
125