xref: /openbmc/qemu/target/cris/helper.c (revision 37677d7d)
1 /*
2  *  CRIS helper routines.
3  *
4  *  Copyright (c) 2007 AXIS Communications AB
5  *  Written by Edgar E. Iglesias.
6  *
7  * This library is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2 of the License, or (at your option) any later version.
11  *
12  * This library is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
19  */
20 
21 #include "qemu/osdep.h"
22 #include "cpu.h"
23 #include "mmu.h"
24 #include "qemu/host-utils.h"
25 #include "exec/exec-all.h"
26 #include "exec/cpu_ldst.h"
27 #include "exec/helper-proto.h"
28 
29 
30 //#define CRIS_HELPER_DEBUG
31 
32 
33 #ifdef CRIS_HELPER_DEBUG
34 #define D(x) x
35 #define D_LOG(...) qemu_log(__VA_ARGS__)
36 #else
37 #define D(x)
38 #define D_LOG(...) do { } while (0)
39 #endif
40 
41 #if defined(CONFIG_USER_ONLY)
42 
43 void cris_cpu_do_interrupt(CPUState *cs)
44 {
45     CRISCPU *cpu = CRIS_CPU(cs);
46     CPUCRISState *env = &cpu->env;
47 
48     cs->exception_index = -1;
49     env->pregs[PR_ERP] = env->pc;
50 }
51 
52 void crisv10_cpu_do_interrupt(CPUState *cs)
53 {
54     cris_cpu_do_interrupt(cs);
55 }
56 
57 bool cris_cpu_tlb_fill(CPUState *cs, vaddr address, int size,
58                        MMUAccessType access_type, int mmu_idx,
59                        bool probe, uintptr_t retaddr)
60 {
61     CRISCPU *cpu = CRIS_CPU(cs);
62 
63     cs->exception_index = 0xaa;
64     cpu->env.pregs[PR_EDA] = address;
65     cpu_loop_exit_restore(cs, retaddr);
66 }
67 
68 #else /* !CONFIG_USER_ONLY */
69 
70 
71 static void cris_shift_ccs(CPUCRISState *env)
72 {
73     uint32_t ccs;
74     /* Apply the ccs shift.  */
75     ccs = env->pregs[PR_CCS];
76     ccs = ((ccs & 0xc0000000) | ((ccs << 12) >> 2)) & ~0x3ff;
77     env->pregs[PR_CCS] = ccs;
78 }
79 
80 bool cris_cpu_tlb_fill(CPUState *cs, vaddr address, int size,
81                        MMUAccessType access_type, int mmu_idx,
82                        bool probe, uintptr_t retaddr)
83 {
84     CRISCPU *cpu = CRIS_CPU(cs);
85     CPUCRISState *env = &cpu->env;
86     struct cris_mmu_result res;
87     int prot, miss;
88     target_ulong phy;
89 
90     miss = cris_mmu_translate(&res, env, address & TARGET_PAGE_MASK,
91                               access_type, mmu_idx, 0);
92     if (likely(!miss)) {
93         /*
94          * Mask off the cache selection bit. The ETRAX busses do not
95          * see the top bit.
96          */
97         phy = res.phy & ~0x80000000;
98         prot = res.prot;
99         tlb_set_page(cs, address & TARGET_PAGE_MASK, phy,
100                      prot, mmu_idx, TARGET_PAGE_SIZE);
101         return true;
102     }
103 
104     if (probe) {
105         return false;
106     }
107 
108     if (cs->exception_index == EXCP_BUSFAULT) {
109         cpu_abort(cs, "CRIS: Illegal recursive bus fault."
110                       "addr=%" VADDR_PRIx " access_type=%d\n",
111                       address, access_type);
112     }
113 
114     env->pregs[PR_EDA] = address;
115     cs->exception_index = EXCP_BUSFAULT;
116     env->fault_vector = res.bf_vec;
117     if (retaddr) {
118         if (cpu_restore_state(cs, retaddr, true)) {
119             /* Evaluate flags after retranslation. */
120             helper_top_evaluate_flags(env);
121         }
122     }
123     cpu_loop_exit(cs);
124 }
125 
126 void crisv10_cpu_do_interrupt(CPUState *cs)
127 {
128     CRISCPU *cpu = CRIS_CPU(cs);
129     CPUCRISState *env = &cpu->env;
130     int ex_vec = -1;
131 
132     D_LOG("exception index=%d interrupt_req=%d\n",
133           cs->exception_index,
134           cs->interrupt_request);
135 
136     if (env->dslot) {
137         /* CRISv10 never takes interrupts while in a delay-slot.  */
138         cpu_abort(cs, "CRIS: Interrupt on delay-slot\n");
139     }
140 
141     assert(!(env->pregs[PR_CCS] & PFIX_FLAG));
142     switch (cs->exception_index) {
143     case EXCP_BREAK:
144         /* These exceptions are genereated by the core itself.
145            ERP should point to the insn following the brk.  */
146         ex_vec = env->trap_vector;
147         env->pregs[PRV10_BRP] = env->pc;
148         break;
149 
150     case EXCP_NMI:
151         /* NMI is hardwired to vector zero.  */
152         ex_vec = 0;
153         env->pregs[PR_CCS] &= ~M_FLAG_V10;
154         env->pregs[PRV10_BRP] = env->pc;
155         break;
156 
157     case EXCP_BUSFAULT:
158         cpu_abort(cs, "Unhandled busfault");
159         break;
160 
161     default:
162         /* The interrupt controller gives us the vector.  */
163         ex_vec = env->interrupt_vector;
164         /* Normal interrupts are taken between
165            TB's.  env->pc is valid here.  */
166         env->pregs[PR_ERP] = env->pc;
167         break;
168     }
169 
170     if (env->pregs[PR_CCS] & U_FLAG) {
171         /* Swap stack pointers.  */
172         env->pregs[PR_USP] = env->regs[R_SP];
173         env->regs[R_SP] = env->ksp;
174     }
175 
176     /* Now that we are in kernel mode, load the handlers address.  */
177     env->pc = cpu_ldl_code(env, env->pregs[PR_EBP] + ex_vec * 4);
178     env->locked_irq = 1;
179     env->pregs[PR_CCS] |= F_FLAG_V10; /* set F.  */
180 
181     qemu_log_mask(CPU_LOG_INT, "%s isr=%x vec=%x ccs=%x pid=%d erp=%x\n",
182                   __func__, env->pc, ex_vec,
183                   env->pregs[PR_CCS],
184                   env->pregs[PR_PID],
185                   env->pregs[PR_ERP]);
186 }
187 
188 void cris_cpu_do_interrupt(CPUState *cs)
189 {
190     CRISCPU *cpu = CRIS_CPU(cs);
191     CPUCRISState *env = &cpu->env;
192     int ex_vec = -1;
193 
194     D_LOG("exception index=%d interrupt_req=%d\n",
195           cs->exception_index,
196           cs->interrupt_request);
197 
198     switch (cs->exception_index) {
199     case EXCP_BREAK:
200         /* These exceptions are genereated by the core itself.
201            ERP should point to the insn following the brk.  */
202         ex_vec = env->trap_vector;
203         env->pregs[PR_ERP] = env->pc;
204         break;
205 
206     case EXCP_NMI:
207         /* NMI is hardwired to vector zero.  */
208         ex_vec = 0;
209         env->pregs[PR_CCS] &= ~M_FLAG_V32;
210         env->pregs[PR_NRP] = env->pc;
211         break;
212 
213     case EXCP_BUSFAULT:
214         ex_vec = env->fault_vector;
215         env->pregs[PR_ERP] = env->pc;
216         break;
217 
218     default:
219         /* The interrupt controller gives us the vector.  */
220         ex_vec = env->interrupt_vector;
221         /* Normal interrupts are taken between
222            TB's.  env->pc is valid here.  */
223         env->pregs[PR_ERP] = env->pc;
224         break;
225     }
226 
227     /* Fill in the IDX field.  */
228     env->pregs[PR_EXS] = (ex_vec & 0xff) << 8;
229 
230     if (env->dslot) {
231         D_LOG("excp isr=%x PC=%x ds=%d SP=%x"
232               " ERP=%x pid=%x ccs=%x cc=%d %x\n",
233               ex_vec, env->pc, env->dslot,
234               env->regs[R_SP],
235               env->pregs[PR_ERP], env->pregs[PR_PID],
236               env->pregs[PR_CCS],
237               env->cc_op, env->cc_mask);
238         /* We loose the btarget, btaken state here so rexec the
239            branch.  */
240         env->pregs[PR_ERP] -= env->dslot;
241         /* Exception starts with dslot cleared.  */
242         env->dslot = 0;
243     }
244 
245     if (env->pregs[PR_CCS] & U_FLAG) {
246         /* Swap stack pointers.  */
247         env->pregs[PR_USP] = env->regs[R_SP];
248         env->regs[R_SP] = env->ksp;
249     }
250 
251     /* Apply the CRIS CCS shift. Clears U if set.  */
252     cris_shift_ccs(env);
253 
254     /* Now that we are in kernel mode, load the handlers address.
255        This load may not fault, real hw leaves that behaviour as
256        undefined.  */
257     env->pc = cpu_ldl_code(env, env->pregs[PR_EBP] + ex_vec * 4);
258 
259     /* Clear the excption_index to avoid spurios hw_aborts for recursive
260        bus faults.  */
261     cs->exception_index = -1;
262 
263     D_LOG("%s isr=%x vec=%x ccs=%x pid=%d erp=%x\n",
264           __func__, env->pc, ex_vec,
265           env->pregs[PR_CCS],
266           env->pregs[PR_PID],
267           env->pregs[PR_ERP]);
268 }
269 
270 hwaddr cris_cpu_get_phys_page_debug(CPUState *cs, vaddr addr)
271 {
272     CRISCPU *cpu = CRIS_CPU(cs);
273     uint32_t phy = addr;
274     struct cris_mmu_result res;
275     int miss;
276 
277     miss = cris_mmu_translate(&res, &cpu->env, addr, 0, 0, 1);
278     /* If D TLB misses, try I TLB.  */
279     if (miss) {
280         miss = cris_mmu_translate(&res, &cpu->env, addr, 2, 0, 1);
281     }
282 
283     if (!miss) {
284         phy = res.phy;
285     }
286     D(fprintf(stderr, "%s %x -> %x\n", __func__, addr, phy));
287     return phy;
288 }
289 #endif
290 
291 bool cris_cpu_exec_interrupt(CPUState *cs, int interrupt_request)
292 {
293     CPUClass *cc = CPU_GET_CLASS(cs);
294     CRISCPU *cpu = CRIS_CPU(cs);
295     CPUCRISState *env = &cpu->env;
296     bool ret = false;
297 
298     if (interrupt_request & CPU_INTERRUPT_HARD
299         && (env->pregs[PR_CCS] & I_FLAG)
300         && !env->locked_irq) {
301         cs->exception_index = EXCP_IRQ;
302         cc->do_interrupt(cs);
303         ret = true;
304     }
305     if (interrupt_request & CPU_INTERRUPT_NMI) {
306         unsigned int m_flag_archval;
307         if (env->pregs[PR_VR] < 32) {
308             m_flag_archval = M_FLAG_V10;
309         } else {
310             m_flag_archval = M_FLAG_V32;
311         }
312         if ((env->pregs[PR_CCS] & m_flag_archval)) {
313             cs->exception_index = EXCP_NMI;
314             cc->do_interrupt(cs);
315             ret = true;
316         }
317     }
318 
319     return ret;
320 }
321