xref: /openbmc/qemu/target/xtensa/exc_helper.c (revision 322b038c)
1 /*
2  * Copyright (c) 2011 - 2019, Max Filippov, Open Source and Linux Lab.
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions are met:
7  *     * Redistributions of source code must retain the above copyright
8  *       notice, this list of conditions and the following disclaimer.
9  *     * Redistributions in binary form must reproduce the above copyright
10  *       notice, this list of conditions and the following disclaimer in the
11  *       documentation and/or other materials provided with the distribution.
12  *     * Neither the name of the Open Source and Linux Lab nor the
13  *       names of its contributors may be used to endorse or promote products
14  *       derived from this software without specific prior written permission.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
17  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
20  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
21  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
22  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
23  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
25  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26  */
27 
28 #include "qemu/osdep.h"
29 #include "qemu/log.h"
30 #include "qemu/main-loop.h"
31 #include "cpu.h"
32 #include "exec/helper-proto.h"
33 #include "qemu/host-utils.h"
34 #include "qemu/atomic.h"
35 #include "exec/exec-all.h"
36 
37 void HELPER(exception)(CPUXtensaState *env, uint32_t excp)
38 {
39     CPUState *cs = env_cpu(env);
40 
41     cs->exception_index = excp;
42     if (excp == EXCP_YIELD) {
43         env->yield_needed = 0;
44     }
45     cpu_loop_exit(cs);
46 }
47 
48 void HELPER(exception_cause)(CPUXtensaState *env, uint32_t pc, uint32_t cause)
49 {
50     uint32_t vector;
51 
52     env->pc = pc;
53     if (env->sregs[PS] & PS_EXCM) {
54         if (env->config->ndepc) {
55             env->sregs[DEPC] = pc;
56         } else {
57             env->sregs[EPC1] = pc;
58         }
59         vector = EXC_DOUBLE;
60     } else {
61         env->sregs[EPC1] = pc;
62         vector = (env->sregs[PS] & PS_UM) ? EXC_USER : EXC_KERNEL;
63     }
64 
65     env->sregs[EXCCAUSE] = cause;
66     env->sregs[PS] |= PS_EXCM;
67 
68     HELPER(exception)(env, vector);
69 }
70 
71 void HELPER(exception_cause_vaddr)(CPUXtensaState *env,
72                                    uint32_t pc, uint32_t cause, uint32_t vaddr)
73 {
74     env->sregs[EXCVADDR] = vaddr;
75     HELPER(exception_cause)(env, pc, cause);
76 }
77 
78 void debug_exception_env(CPUXtensaState *env, uint32_t cause)
79 {
80     if (xtensa_get_cintlevel(env) < env->config->debug_level) {
81         HELPER(debug_exception)(env, env->pc, cause);
82     }
83 }
84 
85 void HELPER(debug_exception)(CPUXtensaState *env, uint32_t pc, uint32_t cause)
86 {
87     unsigned level = env->config->debug_level;
88 
89     env->pc = pc;
90     env->sregs[DEBUGCAUSE] = cause;
91     env->sregs[EPC1 + level - 1] = pc;
92     env->sregs[EPS2 + level - 2] = env->sregs[PS];
93     env->sregs[PS] = (env->sregs[PS] & ~PS_INTLEVEL) | PS_EXCM |
94         (level << PS_INTLEVEL_SHIFT);
95     HELPER(exception)(env, EXC_DEBUG);
96 }
97 
98 #ifndef CONFIG_USER_ONLY
99 
100 void HELPER(waiti)(CPUXtensaState *env, uint32_t pc, uint32_t intlevel)
101 {
102     CPUState *cpu = env_cpu(env);
103 
104     env->pc = pc;
105     env->sregs[PS] = (env->sregs[PS] & ~PS_INTLEVEL) |
106         (intlevel << PS_INTLEVEL_SHIFT);
107 
108     bql_lock();
109     check_interrupts(env);
110     bql_unlock();
111 
112     if (env->pending_irq_level) {
113         cpu_loop_exit(cpu);
114         return;
115     }
116 
117     cpu->halted = 1;
118     HELPER(exception)(env, EXCP_HLT);
119 }
120 
121 void HELPER(check_interrupts)(CPUXtensaState *env)
122 {
123     bql_lock();
124     check_interrupts(env);
125     bql_unlock();
126 }
127 
128 void HELPER(intset)(CPUXtensaState *env, uint32_t v)
129 {
130     qatomic_or(&env->sregs[INTSET],
131               v & env->config->inttype_mask[INTTYPE_SOFTWARE]);
132 }
133 
134 static void intclear(CPUXtensaState *env, uint32_t v)
135 {
136     qatomic_and(&env->sregs[INTSET], ~v);
137 }
138 
139 void HELPER(intclear)(CPUXtensaState *env, uint32_t v)
140 {
141     intclear(env, v & (env->config->inttype_mask[INTTYPE_SOFTWARE] |
142                        env->config->inttype_mask[INTTYPE_EDGE]));
143 }
144 
145 static uint32_t relocated_vector(CPUXtensaState *env, uint32_t vector)
146 {
147     if (xtensa_option_enabled(env->config,
148                               XTENSA_OPTION_RELOCATABLE_VECTOR)) {
149         return vector - env->config->vecbase + env->sregs[VECBASE];
150     } else {
151         return vector;
152     }
153 }
154 
155 /*!
156  * Handle penging IRQ.
157  * For the high priority interrupt jump to the corresponding interrupt vector.
158  * For the level-1 interrupt convert it to either user, kernel or double
159  * exception with the 'level-1 interrupt' exception cause.
160  */
161 static void handle_interrupt(CPUXtensaState *env)
162 {
163     int level = env->pending_irq_level;
164 
165     if ((level > xtensa_get_cintlevel(env) &&
166          level <= env->config->nlevel &&
167          (env->config->level_mask[level] &
168           env->sregs[INTSET] & env->sregs[INTENABLE])) ||
169         level == env->config->nmi_level) {
170         CPUState *cs = env_cpu(env);
171 
172         if (level > 1) {
173             /* env->config->nlevel check should have ensured this */
174             assert(level < sizeof(env->config->interrupt_vector));
175 
176             env->sregs[EPC1 + level - 1] = env->pc;
177             env->sregs[EPS2 + level - 2] = env->sregs[PS];
178             env->sregs[PS] =
179                 (env->sregs[PS] & ~PS_INTLEVEL) | level | PS_EXCM;
180             env->pc = relocated_vector(env,
181                                        env->config->interrupt_vector[level]);
182             if (level == env->config->nmi_level) {
183                 intclear(env, env->config->inttype_mask[INTTYPE_NMI]);
184             }
185         } else {
186             env->sregs[EXCCAUSE] = LEVEL1_INTERRUPT_CAUSE;
187 
188             if (env->sregs[PS] & PS_EXCM) {
189                 if (env->config->ndepc) {
190                     env->sregs[DEPC] = env->pc;
191                 } else {
192                     env->sregs[EPC1] = env->pc;
193                 }
194                 cs->exception_index = EXC_DOUBLE;
195             } else {
196                 env->sregs[EPC1] = env->pc;
197                 cs->exception_index =
198                     (env->sregs[PS] & PS_UM) ? EXC_USER : EXC_KERNEL;
199             }
200             env->sregs[PS] |= PS_EXCM;
201         }
202     }
203 }
204 
205 /* Called from cpu_handle_interrupt with BQL held */
206 void xtensa_cpu_do_interrupt(CPUState *cs)
207 {
208     XtensaCPU *cpu = XTENSA_CPU(cs);
209     CPUXtensaState *env = &cpu->env;
210 
211     if (cs->exception_index == EXC_IRQ) {
212         qemu_log_mask(CPU_LOG_INT,
213                       "%s(EXC_IRQ) level = %d, cintlevel = %d, "
214                       "pc = %08x, a0 = %08x, ps = %08x, "
215                       "intset = %08x, intenable = %08x, "
216                       "ccount = %08x\n",
217                       __func__, env->pending_irq_level,
218                       xtensa_get_cintlevel(env),
219                       env->pc, env->regs[0], env->sregs[PS],
220                       env->sregs[INTSET], env->sregs[INTENABLE],
221                       env->sregs[CCOUNT]);
222         handle_interrupt(env);
223     }
224 
225     switch (cs->exception_index) {
226     case EXC_WINDOW_OVERFLOW4:
227     case EXC_WINDOW_UNDERFLOW4:
228     case EXC_WINDOW_OVERFLOW8:
229     case EXC_WINDOW_UNDERFLOW8:
230     case EXC_WINDOW_OVERFLOW12:
231     case EXC_WINDOW_UNDERFLOW12:
232     case EXC_KERNEL:
233     case EXC_USER:
234     case EXC_DOUBLE:
235     case EXC_DEBUG:
236         qemu_log_mask(CPU_LOG_INT, "%s(%d) "
237                       "pc = %08x, a0 = %08x, ps = %08x, ccount = %08x\n",
238                       __func__, cs->exception_index,
239                       env->pc, env->regs[0], env->sregs[PS],
240                       env->sregs[CCOUNT]);
241         if (env->config->exception_vector[cs->exception_index]) {
242             uint32_t vector;
243 
244             vector = env->config->exception_vector[cs->exception_index];
245             env->pc = relocated_vector(env, vector);
246         } else {
247             qemu_log_mask(CPU_LOG_INT,
248                           "%s(pc = %08x) bad exception_index: %d\n",
249                           __func__, env->pc, cs->exception_index);
250         }
251         break;
252 
253     case EXC_IRQ:
254         break;
255 
256     default:
257         qemu_log("%s(pc = %08x) unknown exception_index: %d\n",
258                  __func__, env->pc, cs->exception_index);
259         break;
260     }
261     check_interrupts(env);
262 }
263 
264 bool xtensa_cpu_exec_interrupt(CPUState *cs, int interrupt_request)
265 {
266     if (interrupt_request & CPU_INTERRUPT_HARD) {
267         cs->exception_index = EXC_IRQ;
268         xtensa_cpu_do_interrupt(cs);
269         return true;
270     }
271     return false;
272 }
273 
274 #endif /* !CONFIG_USER_ONLY */
275