xref: /openbmc/qemu/target/xtensa/exc_helper.c (revision dbdf841b)
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 "exec/exec-all.h"
35 
36 void HELPER(exception)(CPUXtensaState *env, uint32_t excp)
37 {
38     CPUState *cs = env_cpu(env);
39 
40     cs->exception_index = excp;
41     if (excp == EXCP_YIELD) {
42         env->yield_needed = 0;
43     }
44     cpu_loop_exit(cs);
45 }
46 
47 void HELPER(exception_cause)(CPUXtensaState *env, uint32_t pc, uint32_t cause)
48 {
49     uint32_t vector;
50 
51     env->pc = pc;
52     if (env->sregs[PS] & PS_EXCM) {
53         if (env->config->ndepc) {
54             env->sregs[DEPC] = pc;
55         } else {
56             env->sregs[EPC1] = pc;
57         }
58         vector = EXC_DOUBLE;
59     } else {
60         env->sregs[EPC1] = pc;
61         vector = (env->sregs[PS] & PS_UM) ? EXC_USER : EXC_KERNEL;
62     }
63 
64     env->sregs[EXCCAUSE] = cause;
65     env->sregs[PS] |= PS_EXCM;
66 
67     HELPER(exception)(env, vector);
68 }
69 
70 void HELPER(exception_cause_vaddr)(CPUXtensaState *env,
71                                    uint32_t pc, uint32_t cause, uint32_t vaddr)
72 {
73     env->sregs[EXCVADDR] = vaddr;
74     HELPER(exception_cause)(env, pc, cause);
75 }
76 
77 void debug_exception_env(CPUXtensaState *env, uint32_t cause)
78 {
79     if (xtensa_get_cintlevel(env) < env->config->debug_level) {
80         HELPER(debug_exception)(env, env->pc, cause);
81     }
82 }
83 
84 void HELPER(debug_exception)(CPUXtensaState *env, uint32_t pc, uint32_t cause)
85 {
86     unsigned level = env->config->debug_level;
87 
88     env->pc = pc;
89     env->sregs[DEBUGCAUSE] = cause;
90     env->sregs[EPC1 + level - 1] = pc;
91     env->sregs[EPS2 + level - 2] = env->sregs[PS];
92     env->sregs[PS] = (env->sregs[PS] & ~PS_INTLEVEL) | PS_EXCM |
93         (level << PS_INTLEVEL_SHIFT);
94     HELPER(exception)(env, EXC_DEBUG);
95 }
96 
97 #ifndef CONFIG_USER_ONLY
98 
99 void HELPER(waiti)(CPUXtensaState *env, uint32_t pc, uint32_t intlevel)
100 {
101     CPUState *cpu = env_cpu(env);
102 
103     env->pc = pc;
104     env->sregs[PS] = (env->sregs[PS] & ~PS_INTLEVEL) |
105         (intlevel << PS_INTLEVEL_SHIFT);
106 
107     qemu_mutex_lock_iothread();
108     check_interrupts(env);
109     qemu_mutex_unlock_iothread();
110 
111     if (env->pending_irq_level) {
112         cpu_loop_exit(cpu);
113         return;
114     }
115 
116     cpu->halted = 1;
117     HELPER(exception)(env, EXCP_HLT);
118 }
119 
120 void HELPER(check_interrupts)(CPUXtensaState *env)
121 {
122     qemu_mutex_lock_iothread();
123     check_interrupts(env);
124     qemu_mutex_unlock_iothread();
125 }
126 
127 void HELPER(intset)(CPUXtensaState *env, uint32_t v)
128 {
129     qatomic_or(&env->sregs[INTSET],
130               v & env->config->inttype_mask[INTTYPE_SOFTWARE]);
131 }
132 
133 static void intclear(CPUXtensaState *env, uint32_t v)
134 {
135     qatomic_and(&env->sregs[INTSET], ~v);
136 }
137 
138 void HELPER(intclear)(CPUXtensaState *env, uint32_t v)
139 {
140     intclear(env, v & (env->config->inttype_mask[INTTYPE_SOFTWARE] |
141                        env->config->inttype_mask[INTTYPE_EDGE]));
142 }
143 
144 static uint32_t relocated_vector(CPUXtensaState *env, uint32_t vector)
145 {
146     if (xtensa_option_enabled(env->config,
147                               XTENSA_OPTION_RELOCATABLE_VECTOR)) {
148         return vector - env->config->vecbase + env->sregs[VECBASE];
149     } else {
150         return vector;
151     }
152 }
153 
154 /*!
155  * Handle penging IRQ.
156  * For the high priority interrupt jump to the corresponding interrupt vector.
157  * For the level-1 interrupt convert it to either user, kernel or double
158  * exception with the 'level-1 interrupt' exception cause.
159  */
160 static void handle_interrupt(CPUXtensaState *env)
161 {
162     int level = env->pending_irq_level;
163 
164     if ((level > xtensa_get_cintlevel(env) &&
165          level <= env->config->nlevel &&
166          (env->config->level_mask[level] &
167           env->sregs[INTSET] & env->sregs[INTENABLE])) ||
168         level == env->config->nmi_level) {
169         CPUState *cs = env_cpu(env);
170 
171         if (level > 1) {
172             /* env->config->nlevel check should have ensured this */
173             assert(level < sizeof(env->config->interrupt_vector));
174 
175             env->sregs[EPC1 + level - 1] = env->pc;
176             env->sregs[EPS2 + level - 2] = env->sregs[PS];
177             env->sregs[PS] =
178                 (env->sregs[PS] & ~PS_INTLEVEL) | level | PS_EXCM;
179             env->pc = relocated_vector(env,
180                                        env->config->interrupt_vector[level]);
181             if (level == env->config->nmi_level) {
182                 intclear(env, env->config->inttype_mask[INTTYPE_NMI]);
183             }
184         } else {
185             env->sregs[EXCCAUSE] = LEVEL1_INTERRUPT_CAUSE;
186 
187             if (env->sregs[PS] & PS_EXCM) {
188                 if (env->config->ndepc) {
189                     env->sregs[DEPC] = env->pc;
190                 } else {
191                     env->sregs[EPC1] = env->pc;
192                 }
193                 cs->exception_index = EXC_DOUBLE;
194             } else {
195                 env->sregs[EPC1] = env->pc;
196                 cs->exception_index =
197                     (env->sregs[PS] & PS_UM) ? EXC_USER : EXC_KERNEL;
198             }
199             env->sregs[PS] |= PS_EXCM;
200         }
201     }
202 }
203 
204 /* Called from cpu_handle_interrupt with BQL held */
205 void xtensa_cpu_do_interrupt(CPUState *cs)
206 {
207     XtensaCPU *cpu = XTENSA_CPU(cs);
208     CPUXtensaState *env = &cpu->env;
209 
210     if (cs->exception_index == EXC_IRQ) {
211         qemu_log_mask(CPU_LOG_INT,
212                       "%s(EXC_IRQ) level = %d, cintlevel = %d, "
213                       "pc = %08x, a0 = %08x, ps = %08x, "
214                       "intset = %08x, intenable = %08x, "
215                       "ccount = %08x\n",
216                       __func__, env->pending_irq_level,
217                       xtensa_get_cintlevel(env),
218                       env->pc, env->regs[0], env->sregs[PS],
219                       env->sregs[INTSET], env->sregs[INTENABLE],
220                       env->sregs[CCOUNT]);
221         handle_interrupt(env);
222     }
223 
224     switch (cs->exception_index) {
225     case EXC_WINDOW_OVERFLOW4:
226     case EXC_WINDOW_UNDERFLOW4:
227     case EXC_WINDOW_OVERFLOW8:
228     case EXC_WINDOW_UNDERFLOW8:
229     case EXC_WINDOW_OVERFLOW12:
230     case EXC_WINDOW_UNDERFLOW12:
231     case EXC_KERNEL:
232     case EXC_USER:
233     case EXC_DOUBLE:
234     case EXC_DEBUG:
235         qemu_log_mask(CPU_LOG_INT, "%s(%d) "
236                       "pc = %08x, a0 = %08x, ps = %08x, ccount = %08x\n",
237                       __func__, cs->exception_index,
238                       env->pc, env->regs[0], env->sregs[PS],
239                       env->sregs[CCOUNT]);
240         if (env->config->exception_vector[cs->exception_index]) {
241             uint32_t vector;
242 
243             vector = env->config->exception_vector[cs->exception_index];
244             env->pc = relocated_vector(env, vector);
245         } else {
246             qemu_log_mask(CPU_LOG_INT,
247                           "%s(pc = %08x) bad exception_index: %d\n",
248                           __func__, env->pc, cs->exception_index);
249         }
250         break;
251 
252     case EXC_IRQ:
253         break;
254 
255     default:
256         qemu_log("%s(pc = %08x) unknown exception_index: %d\n",
257                  __func__, env->pc, cs->exception_index);
258         break;
259     }
260     check_interrupts(env);
261 }
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 
273 #endif /* !CONFIG_USER_ONLY */
274