xref: /openbmc/qemu/target/xtensa/exc_helper.c (revision 99d423e5)
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/main-loop.h"
30 #include "cpu.h"
31 #include "exec/helper-proto.h"
32 #include "qemu/host-utils.h"
33 #include "exec/exec-all.h"
34 
35 void HELPER(exception)(CPUXtensaState *env, uint32_t excp)
36 {
37     CPUState *cs = CPU(xtensa_env_get_cpu(env));
38 
39     cs->exception_index = excp;
40     if (excp == EXCP_YIELD) {
41         env->yield_needed = 0;
42     }
43     if (excp == EXCP_DEBUG) {
44         env->exception_taken = 0;
45     }
46     cpu_loop_exit(cs);
47 }
48 
49 void HELPER(exception_cause)(CPUXtensaState *env, uint32_t pc, uint32_t cause)
50 {
51     uint32_t vector;
52 
53     env->pc = pc;
54     if (env->sregs[PS] & PS_EXCM) {
55         if (env->config->ndepc) {
56             env->sregs[DEPC] = pc;
57         } else {
58             env->sregs[EPC1] = pc;
59         }
60         vector = EXC_DOUBLE;
61     } else {
62         env->sregs[EPC1] = pc;
63         vector = (env->sregs[PS] & PS_UM) ? EXC_USER : EXC_KERNEL;
64     }
65 
66     env->sregs[EXCCAUSE] = cause;
67     env->sregs[PS] |= PS_EXCM;
68 
69     HELPER(exception)(env, vector);
70 }
71 
72 void HELPER(exception_cause_vaddr)(CPUXtensaState *env,
73                                    uint32_t pc, uint32_t cause, uint32_t vaddr)
74 {
75     env->sregs[EXCVADDR] = vaddr;
76     HELPER(exception_cause)(env, pc, cause);
77 }
78 
79 void debug_exception_env(CPUXtensaState *env, uint32_t cause)
80 {
81     if (xtensa_get_cintlevel(env) < env->config->debug_level) {
82         HELPER(debug_exception)(env, env->pc, cause);
83     }
84 }
85 
86 void HELPER(debug_exception)(CPUXtensaState *env, uint32_t pc, uint32_t cause)
87 {
88     unsigned level = env->config->debug_level;
89 
90     env->pc = pc;
91     env->sregs[DEBUGCAUSE] = cause;
92     env->sregs[EPC1 + level - 1] = pc;
93     env->sregs[EPS2 + level - 2] = env->sregs[PS];
94     env->sregs[PS] = (env->sregs[PS] & ~PS_INTLEVEL) | PS_EXCM |
95         (level << PS_INTLEVEL_SHIFT);
96     HELPER(exception)(env, EXC_DEBUG);
97 }
98 
99 #ifndef CONFIG_USER_ONLY
100 
101 void HELPER(waiti)(CPUXtensaState *env, uint32_t pc, uint32_t intlevel)
102 {
103     CPUState *cpu;
104 
105     env->pc = pc;
106     env->sregs[PS] = (env->sregs[PS] & ~PS_INTLEVEL) |
107         (intlevel << PS_INTLEVEL_SHIFT);
108 
109     qemu_mutex_lock_iothread();
110     check_interrupts(env);
111     qemu_mutex_unlock_iothread();
112 
113     if (env->pending_irq_level) {
114         cpu_loop_exit(CPU(xtensa_env_get_cpu(env)));
115         return;
116     }
117 
118     cpu = CPU(xtensa_env_get_cpu(env));
119     cpu->halted = 1;
120     HELPER(exception)(env, EXCP_HLT);
121 }
122 
123 void HELPER(check_interrupts)(CPUXtensaState *env)
124 {
125     qemu_mutex_lock_iothread();
126     check_interrupts(env);
127     qemu_mutex_unlock_iothread();
128 }
129 
130 void HELPER(intset)(CPUXtensaState *env, uint32_t v)
131 {
132     atomic_or(&env->sregs[INTSET],
133               v & env->config->inttype_mask[INTTYPE_SOFTWARE]);
134 }
135 
136 void HELPER(intclear)(CPUXtensaState *env, uint32_t v)
137 {
138     atomic_and(&env->sregs[INTSET],
139                ~(v & (env->config->inttype_mask[INTTYPE_SOFTWARE] |
140                       env->config->inttype_mask[INTTYPE_EDGE])));
141 }
142 
143 static uint32_t relocated_vector(CPUXtensaState *env, uint32_t vector)
144 {
145     if (xtensa_option_enabled(env->config,
146                               XTENSA_OPTION_RELOCATABLE_VECTOR)) {
147         return vector - env->config->vecbase + env->sregs[VECBASE];
148     } else {
149         return vector;
150     }
151 }
152 
153 /*!
154  * Handle penging IRQ.
155  * For the high priority interrupt jump to the corresponding interrupt vector.
156  * For the level-1 interrupt convert it to either user, kernel or double
157  * exception with the 'level-1 interrupt' exception cause.
158  */
159 static void handle_interrupt(CPUXtensaState *env)
160 {
161     int level = env->pending_irq_level;
162 
163     if (level > xtensa_get_cintlevel(env) &&
164         level <= env->config->nlevel &&
165         (env->config->level_mask[level] &
166          env->sregs[INTSET] &
167          env->sregs[INTENABLE])) {
168         CPUState *cs = CPU(xtensa_env_get_cpu(env));
169 
170         if (level > 1) {
171             env->sregs[EPC1 + level - 1] = env->pc;
172             env->sregs[EPS2 + level - 2] = env->sregs[PS];
173             env->sregs[PS] =
174                 (env->sregs[PS] & ~PS_INTLEVEL) | level | PS_EXCM;
175             env->pc = relocated_vector(env,
176                                        env->config->interrupt_vector[level]);
177         } else {
178             env->sregs[EXCCAUSE] = LEVEL1_INTERRUPT_CAUSE;
179 
180             if (env->sregs[PS] & PS_EXCM) {
181                 if (env->config->ndepc) {
182                     env->sregs[DEPC] = env->pc;
183                 } else {
184                     env->sregs[EPC1] = env->pc;
185                 }
186                 cs->exception_index = EXC_DOUBLE;
187             } else {
188                 env->sregs[EPC1] = env->pc;
189                 cs->exception_index =
190                     (env->sregs[PS] & PS_UM) ? EXC_USER : EXC_KERNEL;
191             }
192             env->sregs[PS] |= PS_EXCM;
193         }
194         env->exception_taken = 1;
195     }
196 }
197 
198 /* Called from cpu_handle_interrupt with BQL held */
199 void xtensa_cpu_do_interrupt(CPUState *cs)
200 {
201     XtensaCPU *cpu = XTENSA_CPU(cs);
202     CPUXtensaState *env = &cpu->env;
203 
204     if (cs->exception_index == EXC_IRQ) {
205         qemu_log_mask(CPU_LOG_INT,
206                       "%s(EXC_IRQ) level = %d, cintlevel = %d, "
207                       "pc = %08x, a0 = %08x, ps = %08x, "
208                       "intset = %08x, intenable = %08x, "
209                       "ccount = %08x\n",
210                       __func__, env->pending_irq_level,
211                       xtensa_get_cintlevel(env),
212                       env->pc, env->regs[0], env->sregs[PS],
213                       env->sregs[INTSET], env->sregs[INTENABLE],
214                       env->sregs[CCOUNT]);
215         handle_interrupt(env);
216     }
217 
218     switch (cs->exception_index) {
219     case EXC_WINDOW_OVERFLOW4:
220     case EXC_WINDOW_UNDERFLOW4:
221     case EXC_WINDOW_OVERFLOW8:
222     case EXC_WINDOW_UNDERFLOW8:
223     case EXC_WINDOW_OVERFLOW12:
224     case EXC_WINDOW_UNDERFLOW12:
225     case EXC_KERNEL:
226     case EXC_USER:
227     case EXC_DOUBLE:
228     case EXC_DEBUG:
229         qemu_log_mask(CPU_LOG_INT, "%s(%d) "
230                       "pc = %08x, a0 = %08x, ps = %08x, ccount = %08x\n",
231                       __func__, cs->exception_index,
232                       env->pc, env->regs[0], env->sregs[PS],
233                       env->sregs[CCOUNT]);
234         if (env->config->exception_vector[cs->exception_index]) {
235             uint32_t vector;
236 
237             vector = env->config->exception_vector[cs->exception_index];
238             env->pc = relocated_vector(env, vector);
239             env->exception_taken = 1;
240         } else {
241             qemu_log_mask(CPU_LOG_INT,
242                           "%s(pc = %08x) bad exception_index: %d\n",
243                           __func__, env->pc, cs->exception_index);
244         }
245         break;
246 
247     case EXC_IRQ:
248         break;
249 
250     default:
251         qemu_log("%s(pc = %08x) unknown exception_index: %d\n",
252                  __func__, env->pc, cs->exception_index);
253         break;
254     }
255     check_interrupts(env);
256 }
257 #else
258 void xtensa_cpu_do_interrupt(CPUState *cs)
259 {
260 }
261 #endif
262 
263 bool xtensa_cpu_exec_interrupt(CPUState *cs, int interrupt_request)
264 {
265     if (interrupt_request & CPU_INTERRUPT_HARD) {
266         cs->exception_index = EXC_IRQ;
267         xtensa_cpu_do_interrupt(cs);
268         return true;
269     }
270     return false;
271 }
272