xref: /openbmc/qemu/target/openrisc/interrupt.c (revision 17b3c353)
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 
29 void openrisc_cpu_do_interrupt(CPUState *cs)
30 {
31     OpenRISCCPU *cpu = OPENRISC_CPU(cs);
32     CPUOpenRISCState *env = &cpu->env;
33     int exception = cs->exception_index;
34 
35     env->epcr = env->pc;
36     if (exception == EXCP_SYSCALL) {
37         env->epcr += 4;
38     }
39     /* When we have an illegal instruction the error effective address
40        shall be set to the illegal instruction address.  */
41     if (exception == EXCP_ILLEGAL) {
42         env->eear = env->pc;
43     }
44 
45     /* During exceptions esr is populared with the pre-exception sr.  */
46     env->esr = cpu_get_sr(env);
47     /* In parallel sr is updated to disable mmu, interrupts, timers and
48        set the delay slot exception flag.  */
49     env->sr &= ~SR_DME;
50     env->sr &= ~SR_IME;
51     env->sr |= SR_SM;
52     env->sr &= ~SR_IEE;
53     env->sr &= ~SR_TEE;
54     env->pmr &= ~PMR_DME;
55     env->pmr &= ~PMR_SME;
56     env->lock_addr = -1;
57 
58     /* Set/clear dsx to indicate if we are in a delay slot exception.  */
59     if (env->dflag) {
60         env->dflag = 0;
61         env->sr |= SR_DSX;
62         env->epcr -= 4;
63     } else {
64         env->sr &= ~SR_DSX;
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, "INT: %s\n", int_name[exception]);
86 
87         hwaddr vect_pc = exception << 8;
88         if (env->cpucfgr & CPUCFGR_EVBARP) {
89             vect_pc |= env->evbar;
90         }
91         if (env->sr & SR_EPH) {
92             vect_pc |= 0xf0000000;
93         }
94         env->pc = vect_pc;
95     } else {
96         cpu_abort(cs, "Unhandled exception 0x%x\n", exception);
97     }
98 
99     cs->exception_index = -1;
100 }
101 
102 bool openrisc_cpu_exec_interrupt(CPUState *cs, int interrupt_request)
103 {
104     OpenRISCCPU *cpu = OPENRISC_CPU(cs);
105     CPUOpenRISCState *env = &cpu->env;
106     int idx = -1;
107 
108     if ((interrupt_request & CPU_INTERRUPT_HARD) && (env->sr & SR_IEE)) {
109         idx = EXCP_INT;
110     }
111     if ((interrupt_request & CPU_INTERRUPT_TIMER) && (env->sr & SR_TEE)) {
112         idx = EXCP_TICK;
113     }
114     if (idx >= 0) {
115         cs->exception_index = idx;
116         openrisc_cpu_do_interrupt(cs);
117         return true;
118     }
119     return false;
120 }
121