xref: /openbmc/qemu/target/xtensa/exc_helper.c (revision 654d6b04)
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     cpu_loop_exit(cs);
44 }
45 
46 void HELPER(exception_cause)(CPUXtensaState *env, uint32_t pc, uint32_t cause)
47 {
48     uint32_t vector;
49 
50     env->pc = pc;
51     if (env->sregs[PS] & PS_EXCM) {
52         if (env->config->ndepc) {
53             env->sregs[DEPC] = pc;
54         } else {
55             env->sregs[EPC1] = pc;
56         }
57         vector = EXC_DOUBLE;
58     } else {
59         env->sregs[EPC1] = pc;
60         vector = (env->sregs[PS] & PS_UM) ? EXC_USER : EXC_KERNEL;
61     }
62 
63     env->sregs[EXCCAUSE] = cause;
64     env->sregs[PS] |= PS_EXCM;
65 
66     HELPER(exception)(env, vector);
67 }
68 
69 void HELPER(exception_cause_vaddr)(CPUXtensaState *env,
70                                    uint32_t pc, uint32_t cause, uint32_t vaddr)
71 {
72     env->sregs[EXCVADDR] = vaddr;
73     HELPER(exception_cause)(env, pc, cause);
74 }
75 
76 void debug_exception_env(CPUXtensaState *env, uint32_t cause)
77 {
78     if (xtensa_get_cintlevel(env) < env->config->debug_level) {
79         HELPER(debug_exception)(env, env->pc, cause);
80     }
81 }
82 
83 void HELPER(debug_exception)(CPUXtensaState *env, uint32_t pc, uint32_t cause)
84 {
85     unsigned level = env->config->debug_level;
86 
87     env->pc = pc;
88     env->sregs[DEBUGCAUSE] = cause;
89     env->sregs[EPC1 + level - 1] = pc;
90     env->sregs[EPS2 + level - 2] = env->sregs[PS];
91     env->sregs[PS] = (env->sregs[PS] & ~PS_INTLEVEL) | PS_EXCM |
92         (level << PS_INTLEVEL_SHIFT);
93     HELPER(exception)(env, EXC_DEBUG);
94 }
95 
96 #ifndef CONFIG_USER_ONLY
97 
98 void HELPER(waiti)(CPUXtensaState *env, uint32_t pc, uint32_t intlevel)
99 {
100     CPUState *cpu = env_cpu(env);
101 
102     env->pc = pc;
103     env->sregs[PS] = (env->sregs[PS] & ~PS_INTLEVEL) |
104         (intlevel << PS_INTLEVEL_SHIFT);
105 
106     qemu_mutex_lock_iothread();
107     check_interrupts(env);
108     qemu_mutex_unlock_iothread();
109 
110     if (env->pending_irq_level) {
111         cpu_loop_exit(cpu);
112         return;
113     }
114 
115     cpu->halted = 1;
116     HELPER(exception)(env, EXCP_HLT);
117 }
118 
119 void HELPER(check_interrupts)(CPUXtensaState *env)
120 {
121     qemu_mutex_lock_iothread();
122     check_interrupts(env);
123     qemu_mutex_unlock_iothread();
124 }
125 
126 void HELPER(intset)(CPUXtensaState *env, uint32_t v)
127 {
128     qatomic_or(&env->sregs[INTSET],
129               v & env->config->inttype_mask[INTTYPE_SOFTWARE]);
130 }
131 
132 static void intclear(CPUXtensaState *env, uint32_t v)
133 {
134     qatomic_and(&env->sregs[INTSET], ~v);
135 }
136 
137 void HELPER(intclear)(CPUXtensaState *env, uint32_t v)
138 {
139     intclear(env, 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] & env->sregs[INTENABLE])) ||
167         level == env->config->nmi_level) {
168         CPUState *cs = env_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             if (level == env->config->nmi_level) {
178                 intclear(env, env->config->inttype_mask[INTTYPE_NMI]);
179             }
180         } else {
181             env->sregs[EXCCAUSE] = LEVEL1_INTERRUPT_CAUSE;
182 
183             if (env->sregs[PS] & PS_EXCM) {
184                 if (env->config->ndepc) {
185                     env->sregs[DEPC] = env->pc;
186                 } else {
187                     env->sregs[EPC1] = env->pc;
188                 }
189                 cs->exception_index = EXC_DOUBLE;
190             } else {
191                 env->sregs[EPC1] = env->pc;
192                 cs->exception_index =
193                     (env->sregs[PS] & PS_UM) ? EXC_USER : EXC_KERNEL;
194             }
195             env->sregs[PS] |= PS_EXCM;
196         }
197     }
198 }
199 
200 /* Called from cpu_handle_interrupt with BQL held */
201 void xtensa_cpu_do_interrupt(CPUState *cs)
202 {
203     XtensaCPU *cpu = XTENSA_CPU(cs);
204     CPUXtensaState *env = &cpu->env;
205 
206     if (cs->exception_index == EXC_IRQ) {
207         qemu_log_mask(CPU_LOG_INT,
208                       "%s(EXC_IRQ) level = %d, cintlevel = %d, "
209                       "pc = %08x, a0 = %08x, ps = %08x, "
210                       "intset = %08x, intenable = %08x, "
211                       "ccount = %08x\n",
212                       __func__, env->pending_irq_level,
213                       xtensa_get_cintlevel(env),
214                       env->pc, env->regs[0], env->sregs[PS],
215                       env->sregs[INTSET], env->sregs[INTENABLE],
216                       env->sregs[CCOUNT]);
217         handle_interrupt(env);
218     }
219 
220     switch (cs->exception_index) {
221     case EXC_WINDOW_OVERFLOW4:
222     case EXC_WINDOW_UNDERFLOW4:
223     case EXC_WINDOW_OVERFLOW8:
224     case EXC_WINDOW_UNDERFLOW8:
225     case EXC_WINDOW_OVERFLOW12:
226     case EXC_WINDOW_UNDERFLOW12:
227     case EXC_KERNEL:
228     case EXC_USER:
229     case EXC_DOUBLE:
230     case EXC_DEBUG:
231         qemu_log_mask(CPU_LOG_INT, "%s(%d) "
232                       "pc = %08x, a0 = %08x, ps = %08x, ccount = %08x\n",
233                       __func__, cs->exception_index,
234                       env->pc, env->regs[0], env->sregs[PS],
235                       env->sregs[CCOUNT]);
236         if (env->config->exception_vector[cs->exception_index]) {
237             uint32_t vector;
238 
239             vector = env->config->exception_vector[cs->exception_index];
240             env->pc = relocated_vector(env, vector);
241         } else {
242             qemu_log_mask(CPU_LOG_INT,
243                           "%s(pc = %08x) bad exception_index: %d\n",
244                           __func__, env->pc, cs->exception_index);
245         }
246         break;
247 
248     case EXC_IRQ:
249         break;
250 
251     default:
252         qemu_log("%s(pc = %08x) unknown exception_index: %d\n",
253                  __func__, env->pc, cs->exception_index);
254         break;
255     }
256     check_interrupts(env);
257 }
258 
259 bool xtensa_cpu_exec_interrupt(CPUState *cs, int interrupt_request)
260 {
261     if (interrupt_request & CPU_INTERRUPT_HARD) {
262         cs->exception_index = EXC_IRQ;
263         xtensa_cpu_do_interrupt(cs);
264         return true;
265     }
266     return false;
267 }
268 
269 #endif /* !CONFIG_USER_ONLY */
270