xref: /openbmc/qemu/target/xtensa/exc_helper.c (revision 5e140196)
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 = env_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 = env_cpu(env);
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);
115         return;
116     }
117 
118     cpu->halted = 1;
119     HELPER(exception)(env, EXCP_HLT);
120 }
121 
122 void HELPER(check_interrupts)(CPUXtensaState *env)
123 {
124     qemu_mutex_lock_iothread();
125     check_interrupts(env);
126     qemu_mutex_unlock_iothread();
127 }
128 
129 void HELPER(intset)(CPUXtensaState *env, uint32_t v)
130 {
131     atomic_or(&env->sregs[INTSET],
132               v & env->config->inttype_mask[INTTYPE_SOFTWARE]);
133 }
134 
135 void HELPER(intclear)(CPUXtensaState *env, uint32_t v)
136 {
137     atomic_and(&env->sregs[INTSET],
138                ~(v & (env->config->inttype_mask[INTTYPE_SOFTWARE] |
139                       env->config->inttype_mask[INTTYPE_EDGE])));
140 }
141 
142 static uint32_t relocated_vector(CPUXtensaState *env, uint32_t vector)
143 {
144     if (xtensa_option_enabled(env->config,
145                               XTENSA_OPTION_RELOCATABLE_VECTOR)) {
146         return vector - env->config->vecbase + env->sregs[VECBASE];
147     } else {
148         return vector;
149     }
150 }
151 
152 /*!
153  * Handle penging IRQ.
154  * For the high priority interrupt jump to the corresponding interrupt vector.
155  * For the level-1 interrupt convert it to either user, kernel or double
156  * exception with the 'level-1 interrupt' exception cause.
157  */
158 static void handle_interrupt(CPUXtensaState *env)
159 {
160     int level = env->pending_irq_level;
161 
162     if (level > xtensa_get_cintlevel(env) &&
163         level <= env->config->nlevel &&
164         (env->config->level_mask[level] &
165          env->sregs[INTSET] &
166          env->sregs[INTENABLE])) {
167         CPUState *cs = env_cpu(env);
168 
169         if (level > 1) {
170             env->sregs[EPC1 + level - 1] = env->pc;
171             env->sregs[EPS2 + level - 2] = env->sregs[PS];
172             env->sregs[PS] =
173                 (env->sregs[PS] & ~PS_INTLEVEL) | level | PS_EXCM;
174             env->pc = relocated_vector(env,
175                                        env->config->interrupt_vector[level]);
176         } else {
177             env->sregs[EXCCAUSE] = LEVEL1_INTERRUPT_CAUSE;
178 
179             if (env->sregs[PS] & PS_EXCM) {
180                 if (env->config->ndepc) {
181                     env->sregs[DEPC] = env->pc;
182                 } else {
183                     env->sregs[EPC1] = env->pc;
184                 }
185                 cs->exception_index = EXC_DOUBLE;
186             } else {
187                 env->sregs[EPC1] = env->pc;
188                 cs->exception_index =
189                     (env->sregs[PS] & PS_UM) ? EXC_USER : EXC_KERNEL;
190             }
191             env->sregs[PS] |= PS_EXCM;
192         }
193         env->exception_taken = 1;
194     }
195 }
196 
197 /* Called from cpu_handle_interrupt with BQL held */
198 void xtensa_cpu_do_interrupt(CPUState *cs)
199 {
200     XtensaCPU *cpu = XTENSA_CPU(cs);
201     CPUXtensaState *env = &cpu->env;
202 
203     if (cs->exception_index == EXC_IRQ) {
204         qemu_log_mask(CPU_LOG_INT,
205                       "%s(EXC_IRQ) level = %d, cintlevel = %d, "
206                       "pc = %08x, a0 = %08x, ps = %08x, "
207                       "intset = %08x, intenable = %08x, "
208                       "ccount = %08x\n",
209                       __func__, env->pending_irq_level,
210                       xtensa_get_cintlevel(env),
211                       env->pc, env->regs[0], env->sregs[PS],
212                       env->sregs[INTSET], env->sregs[INTENABLE],
213                       env->sregs[CCOUNT]);
214         handle_interrupt(env);
215     }
216 
217     switch (cs->exception_index) {
218     case EXC_WINDOW_OVERFLOW4:
219     case EXC_WINDOW_UNDERFLOW4:
220     case EXC_WINDOW_OVERFLOW8:
221     case EXC_WINDOW_UNDERFLOW8:
222     case EXC_WINDOW_OVERFLOW12:
223     case EXC_WINDOW_UNDERFLOW12:
224     case EXC_KERNEL:
225     case EXC_USER:
226     case EXC_DOUBLE:
227     case EXC_DEBUG:
228         qemu_log_mask(CPU_LOG_INT, "%s(%d) "
229                       "pc = %08x, a0 = %08x, ps = %08x, ccount = %08x\n",
230                       __func__, cs->exception_index,
231                       env->pc, env->regs[0], env->sregs[PS],
232                       env->sregs[CCOUNT]);
233         if (env->config->exception_vector[cs->exception_index]) {
234             uint32_t vector;
235 
236             vector = env->config->exception_vector[cs->exception_index];
237             env->pc = relocated_vector(env, vector);
238             env->exception_taken = 1;
239         } else {
240             qemu_log_mask(CPU_LOG_INT,
241                           "%s(pc = %08x) bad exception_index: %d\n",
242                           __func__, env->pc, cs->exception_index);
243         }
244         break;
245 
246     case EXC_IRQ:
247         break;
248 
249     default:
250         qemu_log("%s(pc = %08x) unknown exception_index: %d\n",
251                  __func__, env->pc, cs->exception_index);
252         break;
253     }
254     check_interrupts(env);
255 }
256 #else
257 void xtensa_cpu_do_interrupt(CPUState *cs)
258 {
259 }
260 #endif
261 
262 bool xtensa_cpu_exec_interrupt(CPUState *cs, int interrupt_request)
263 {
264     if (interrupt_request & CPU_INTERRUPT_HARD) {
265         cs->exception_index = EXC_IRQ;
266         xtensa_cpu_do_interrupt(cs);
267         return true;
268     }
269     return false;
270 }
271