xref: /openbmc/qemu/target/cris/helper.c (revision 6f03770d)
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 2.1 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 "hw/core/tcg-cpu-ops.h"
24 #include "mmu.h"
25 #include "qemu/host-utils.h"
26 #include "exec/exec-all.h"
27 #include "exec/cpu_ldst.h"
28 #include "exec/helper-proto.h"
29 
30 
31 //#define CRIS_HELPER_DEBUG
32 
33 
34 #ifdef CRIS_HELPER_DEBUG
35 #define D(x) x
36 #define D_LOG(...) qemu_log(__VA_ARGS__)
37 #else
38 #define D(x)
39 #define D_LOG(...) do { } while (0)
40 #endif
41 
42 #if defined(CONFIG_USER_ONLY)
43 
44 void cris_cpu_do_interrupt(CPUState *cs)
45 {
46     CRISCPU *cpu = CRIS_CPU(cs);
47     CPUCRISState *env = &cpu->env;
48 
49     cs->exception_index = -1;
50     env->pregs[PR_ERP] = env->pc;
51 }
52 
53 void crisv10_cpu_do_interrupt(CPUState *cs)
54 {
55     cris_cpu_do_interrupt(cs);
56 }
57 
58 bool cris_cpu_tlb_fill(CPUState *cs, vaddr address, int size,
59                        MMUAccessType access_type, int mmu_idx,
60                        bool probe, uintptr_t retaddr)
61 {
62     CRISCPU *cpu = CRIS_CPU(cs);
63 
64     cs->exception_index = 0xaa;
65     cpu->env.pregs[PR_EDA] = address;
66     cpu_loop_exit_restore(cs, retaddr);
67 }
68 
69 #else /* !CONFIG_USER_ONLY */
70 
71 
72 static void cris_shift_ccs(CPUCRISState *env)
73 {
74     uint32_t ccs;
75     /* Apply the ccs shift.  */
76     ccs = env->pregs[PR_CCS];
77     ccs = ((ccs & 0xc0000000) | ((ccs << 12) >> 2)) & ~0x3ff;
78     env->pregs[PR_CCS] = ccs;
79 }
80 
81 bool cris_cpu_tlb_fill(CPUState *cs, vaddr address, int size,
82                        MMUAccessType access_type, int mmu_idx,
83                        bool probe, uintptr_t retaddr)
84 {
85     CRISCPU *cpu = CRIS_CPU(cs);
86     CPUCRISState *env = &cpu->env;
87     struct cris_mmu_result res;
88     int prot, miss;
89     target_ulong phy;
90 
91     miss = cris_mmu_translate(&res, env, address & TARGET_PAGE_MASK,
92                               access_type, mmu_idx, 0);
93     if (likely(!miss)) {
94         /*
95          * Mask off the cache selection bit. The ETRAX busses do not
96          * see the top bit.
97          */
98         phy = res.phy & ~0x80000000;
99         prot = res.prot;
100         tlb_set_page(cs, address & TARGET_PAGE_MASK, phy,
101                      prot, mmu_idx, TARGET_PAGE_SIZE);
102         return true;
103     }
104 
105     if (probe) {
106         return false;
107     }
108 
109     if (cs->exception_index == EXCP_BUSFAULT) {
110         cpu_abort(cs, "CRIS: Illegal recursive bus fault."
111                       "addr=%" VADDR_PRIx " access_type=%d\n",
112                       address, access_type);
113     }
114 
115     env->pregs[PR_EDA] = address;
116     cs->exception_index = EXCP_BUSFAULT;
117     env->fault_vector = res.bf_vec;
118     if (retaddr) {
119         if (cpu_restore_state(cs, retaddr, true)) {
120             /* Evaluate flags after retranslation. */
121             helper_top_evaluate_flags(env);
122         }
123     }
124     cpu_loop_exit(cs);
125 }
126 
127 void crisv10_cpu_do_interrupt(CPUState *cs)
128 {
129     CRISCPU *cpu = CRIS_CPU(cs);
130     CPUCRISState *env = &cpu->env;
131     int ex_vec = -1;
132 
133     D_LOG("exception index=%d interrupt_req=%d\n",
134           cs->exception_index,
135           cs->interrupt_request);
136 
137     if (env->dslot) {
138         /* CRISv10 never takes interrupts while in a delay-slot.  */
139         cpu_abort(cs, "CRIS: Interrupt on delay-slot\n");
140     }
141 
142     assert(!(env->pregs[PR_CCS] & PFIX_FLAG));
143     switch (cs->exception_index) {
144     case EXCP_BREAK:
145         /* These exceptions are genereated by the core itself.
146            ERP should point to the insn following the brk.  */
147         ex_vec = env->trap_vector;
148         env->pregs[PRV10_BRP] = env->pc;
149         break;
150 
151     case EXCP_NMI:
152         /* NMI is hardwired to vector zero.  */
153         ex_vec = 0;
154         env->pregs[PR_CCS] &= ~M_FLAG_V10;
155         env->pregs[PRV10_BRP] = env->pc;
156         break;
157 
158     case EXCP_BUSFAULT:
159         cpu_abort(cs, "Unhandled busfault");
160         break;
161 
162     default:
163         /* The interrupt controller gives us the vector.  */
164         ex_vec = env->interrupt_vector;
165         /* Normal interrupts are taken between
166            TB's.  env->pc is valid here.  */
167         env->pregs[PR_ERP] = env->pc;
168         break;
169     }
170 
171     if (env->pregs[PR_CCS] & U_FLAG) {
172         /* Swap stack pointers.  */
173         env->pregs[PR_USP] = env->regs[R_SP];
174         env->regs[R_SP] = env->ksp;
175     }
176 
177     /* Now that we are in kernel mode, load the handlers address.  */
178     env->pc = cpu_ldl_code(env, env->pregs[PR_EBP] + ex_vec * 4);
179     env->locked_irq = 1;
180     env->pregs[PR_CCS] |= F_FLAG_V10; /* set F.  */
181 
182     qemu_log_mask(CPU_LOG_INT, "%s isr=%x vec=%x ccs=%x pid=%d erp=%x\n",
183                   __func__, env->pc, ex_vec,
184                   env->pregs[PR_CCS],
185                   env->pregs[PR_PID],
186                   env->pregs[PR_ERP]);
187 }
188 
189 void cris_cpu_do_interrupt(CPUState *cs)
190 {
191     CRISCPU *cpu = CRIS_CPU(cs);
192     CPUCRISState *env = &cpu->env;
193     int ex_vec = -1;
194 
195     D_LOG("exception index=%d interrupt_req=%d\n",
196           cs->exception_index,
197           cs->interrupt_request);
198 
199     switch (cs->exception_index) {
200     case EXCP_BREAK:
201         /* These exceptions are genereated by the core itself.
202            ERP should point to the insn following the brk.  */
203         ex_vec = env->trap_vector;
204         env->pregs[PR_ERP] = env->pc;
205         break;
206 
207     case EXCP_NMI:
208         /* NMI is hardwired to vector zero.  */
209         ex_vec = 0;
210         env->pregs[PR_CCS] &= ~M_FLAG_V32;
211         env->pregs[PR_NRP] = env->pc;
212         break;
213 
214     case EXCP_BUSFAULT:
215         ex_vec = env->fault_vector;
216         env->pregs[PR_ERP] = env->pc;
217         break;
218 
219     default:
220         /* The interrupt controller gives us the vector.  */
221         ex_vec = env->interrupt_vector;
222         /* Normal interrupts are taken between
223            TB's.  env->pc is valid here.  */
224         env->pregs[PR_ERP] = env->pc;
225         break;
226     }
227 
228     /* Fill in the IDX field.  */
229     env->pregs[PR_EXS] = (ex_vec & 0xff) << 8;
230 
231     if (env->dslot) {
232         D_LOG("excp isr=%x PC=%x ds=%d SP=%x"
233               " ERP=%x pid=%x ccs=%x cc=%d %x\n",
234               ex_vec, env->pc, env->dslot,
235               env->regs[R_SP],
236               env->pregs[PR_ERP], env->pregs[PR_PID],
237               env->pregs[PR_CCS],
238               env->cc_op, env->cc_mask);
239         /* We loose the btarget, btaken state here so rexec the
240            branch.  */
241         env->pregs[PR_ERP] -= env->dslot;
242         /* Exception starts with dslot cleared.  */
243         env->dslot = 0;
244     }
245 
246     if (env->pregs[PR_CCS] & U_FLAG) {
247         /* Swap stack pointers.  */
248         env->pregs[PR_USP] = env->regs[R_SP];
249         env->regs[R_SP] = env->ksp;
250     }
251 
252     /* Apply the CRIS CCS shift. Clears U if set.  */
253     cris_shift_ccs(env);
254 
255     /* Now that we are in kernel mode, load the handlers address.
256        This load may not fault, real hw leaves that behaviour as
257        undefined.  */
258     env->pc = cpu_ldl_code(env, env->pregs[PR_EBP] + ex_vec * 4);
259 
260     /* Clear the excption_index to avoid spurios hw_aborts for recursive
261        bus faults.  */
262     cs->exception_index = -1;
263 
264     D_LOG("%s isr=%x vec=%x ccs=%x pid=%d erp=%x\n",
265           __func__, env->pc, ex_vec,
266           env->pregs[PR_CCS],
267           env->pregs[PR_PID],
268           env->pregs[PR_ERP]);
269 }
270 
271 hwaddr cris_cpu_get_phys_page_debug(CPUState *cs, vaddr addr)
272 {
273     CRISCPU *cpu = CRIS_CPU(cs);
274     uint32_t phy = addr;
275     struct cris_mmu_result res;
276     int miss;
277 
278     miss = cris_mmu_translate(&res, &cpu->env, addr, MMU_DATA_LOAD, 0, 1);
279     /* If D TLB misses, try I TLB.  */
280     if (miss) {
281         miss = cris_mmu_translate(&res, &cpu->env, addr, MMU_INST_FETCH, 0, 1);
282     }
283 
284     if (!miss) {
285         phy = res.phy;
286     }
287     D(fprintf(stderr, "%s %x -> %x\n", __func__, addr, phy));
288     return phy;
289 }
290 #endif
291 
292 bool cris_cpu_exec_interrupt(CPUState *cs, int interrupt_request)
293 {
294     CPUClass *cc = CPU_GET_CLASS(cs);
295     CRISCPU *cpu = CRIS_CPU(cs);
296     CPUCRISState *env = &cpu->env;
297     bool ret = false;
298 
299     if (interrupt_request & CPU_INTERRUPT_HARD
300         && (env->pregs[PR_CCS] & I_FLAG)
301         && !env->locked_irq) {
302         cs->exception_index = EXCP_IRQ;
303         cc->tcg_ops->do_interrupt(cs);
304         ret = true;
305     }
306     if (interrupt_request & CPU_INTERRUPT_NMI) {
307         unsigned int m_flag_archval;
308         if (env->pregs[PR_VR] < 32) {
309             m_flag_archval = M_FLAG_V10;
310         } else {
311             m_flag_archval = M_FLAG_V32;
312         }
313         if ((env->pregs[PR_CCS] & m_flag_archval)) {
314             cs->exception_index = EXCP_NMI;
315             cc->tcg_ops->do_interrupt(cs);
316             ret = true;
317         }
318     }
319 
320     return ret;
321 }
322