xref: /openbmc/qemu/target/cris/helper.c (revision 34cc54fb)
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 "qemu/log.h"
23 #include "cpu.h"
24 #include "hw/core/tcg-cpu-ops.h"
25 #include "mmu.h"
26 #include "qemu/host-utils.h"
27 #include "exec/exec-all.h"
28 #include "exec/cpu_ldst.h"
29 #include "exec/helper-proto.h"
30 
31 
32 //#define CRIS_HELPER_DEBUG
33 
34 
35 #ifdef CRIS_HELPER_DEBUG
36 #define D(x) x
37 #define D_LOG(...) qemu_log(__VA_ARGS__)
38 #else
39 #define D(x)
40 #define D_LOG(...) do { } while (0)
41 #endif
42 
43 static void cris_shift_ccs(CPUCRISState *env)
44 {
45     uint32_t ccs;
46     /* Apply the ccs shift.  */
47     ccs = env->pregs[PR_CCS];
48     ccs = ((ccs & 0xc0000000) | ((ccs << 12) >> 2)) & ~0x3ff;
49     env->pregs[PR_CCS] = ccs;
50 }
51 
52 bool cris_cpu_tlb_fill(CPUState *cs, vaddr address, int size,
53                        MMUAccessType access_type, int mmu_idx,
54                        bool probe, uintptr_t retaddr)
55 {
56     CPUCRISState *env = cpu_env(cs);
57     struct cris_mmu_result res;
58     int prot, miss;
59     target_ulong phy;
60 
61     miss = cris_mmu_translate(&res, env, address & TARGET_PAGE_MASK,
62                               access_type, mmu_idx, 0);
63     if (likely(!miss)) {
64         /*
65          * Mask off the cache selection bit. The ETRAX busses do not
66          * see the top bit.
67          */
68         phy = res.phy & ~0x80000000;
69         prot = res.prot;
70         tlb_set_page(cs, address & TARGET_PAGE_MASK, phy,
71                      prot, mmu_idx, TARGET_PAGE_SIZE);
72         return true;
73     }
74 
75     if (probe) {
76         return false;
77     }
78 
79     if (cs->exception_index == EXCP_BUSFAULT) {
80         cpu_abort(cs, "CRIS: Illegal recursive bus fault."
81                       "addr=%" VADDR_PRIx " access_type=%d\n",
82                       address, access_type);
83     }
84 
85     env->pregs[PR_EDA] = address;
86     cs->exception_index = EXCP_BUSFAULT;
87     env->fault_vector = res.bf_vec;
88     if (retaddr) {
89         if (cpu_restore_state(cs, retaddr)) {
90             /* Evaluate flags after retranslation. */
91             helper_top_evaluate_flags(env);
92         }
93     }
94     cpu_loop_exit(cs);
95 }
96 
97 void crisv10_cpu_do_interrupt(CPUState *cs)
98 {
99     CPUCRISState *env = cpu_env(cs);
100     int ex_vec = -1;
101 
102     D_LOG("exception index=%d interrupt_req=%d\n",
103           cs->exception_index,
104           cs->interrupt_request);
105 
106     if (env->dslot) {
107         /* CRISv10 never takes interrupts while in a delay-slot.  */
108         cpu_abort(cs, "CRIS: Interrupt on delay-slot\n");
109     }
110 
111     assert(!(env->pregs[PR_CCS] & PFIX_FLAG));
112     switch (cs->exception_index) {
113     case EXCP_BREAK:
114         /* These exceptions are generated by the core itself.
115            ERP should point to the insn following the brk.  */
116         ex_vec = env->trap_vector;
117         env->pregs[PRV10_BRP] = env->pc;
118         break;
119 
120     case EXCP_NMI:
121         /* NMI is hardwired to vector zero.  */
122         ex_vec = 0;
123         env->pregs[PR_CCS] &= ~M_FLAG_V10;
124         env->pregs[PRV10_BRP] = env->pc;
125         break;
126 
127     case EXCP_BUSFAULT:
128         cpu_abort(cs, "Unhandled busfault");
129         break;
130 
131     default:
132         /* The interrupt controller gives us the vector.  */
133         ex_vec = env->interrupt_vector;
134         /* Normal interrupts are taken between
135            TB's.  env->pc is valid here.  */
136         env->pregs[PR_ERP] = env->pc;
137         break;
138     }
139 
140     if (env->pregs[PR_CCS] & U_FLAG) {
141         /* Swap stack pointers.  */
142         env->pregs[PR_USP] = env->regs[R_SP];
143         env->regs[R_SP] = env->ksp;
144     }
145 
146     /* Now that we are in kernel mode, load the handlers address.  */
147     env->pc = cpu_ldl_code(env, env->pregs[PR_EBP] + ex_vec * 4);
148     env->locked_irq = 1;
149     env->pregs[PR_CCS] |= F_FLAG_V10; /* set F.  */
150 
151     qemu_log_mask(CPU_LOG_INT, "%s isr=%x vec=%x ccs=%x pid=%d erp=%x\n",
152                   __func__, env->pc, ex_vec,
153                   env->pregs[PR_CCS],
154                   env->pregs[PR_PID],
155                   env->pregs[PR_ERP]);
156 }
157 
158 void cris_cpu_do_interrupt(CPUState *cs)
159 {
160     CPUCRISState *env = cpu_env(cs);
161     int ex_vec = -1;
162 
163     D_LOG("exception index=%d interrupt_req=%d\n",
164           cs->exception_index,
165           cs->interrupt_request);
166 
167     switch (cs->exception_index) {
168     case EXCP_BREAK:
169         /* These exceptions are generated by the core itself.
170            ERP should point to the insn following the brk.  */
171         ex_vec = env->trap_vector;
172         env->pregs[PR_ERP] = env->pc;
173         break;
174 
175     case EXCP_NMI:
176         /* NMI is hardwired to vector zero.  */
177         ex_vec = 0;
178         env->pregs[PR_CCS] &= ~M_FLAG_V32;
179         env->pregs[PR_NRP] = env->pc;
180         break;
181 
182     case EXCP_BUSFAULT:
183         ex_vec = env->fault_vector;
184         env->pregs[PR_ERP] = env->pc;
185         break;
186 
187     default:
188         /* The interrupt controller gives us the vector.  */
189         ex_vec = env->interrupt_vector;
190         /* Normal interrupts are taken between
191            TB's.  env->pc is valid here.  */
192         env->pregs[PR_ERP] = env->pc;
193         break;
194     }
195 
196     /* Fill in the IDX field.  */
197     env->pregs[PR_EXS] = (ex_vec & 0xff) << 8;
198 
199     if (env->dslot) {
200         D_LOG("excp isr=%x PC=%x ds=%d SP=%x"
201               " ERP=%x pid=%x ccs=%x cc=%d %x\n",
202               ex_vec, env->pc, env->dslot,
203               env->regs[R_SP],
204               env->pregs[PR_ERP], env->pregs[PR_PID],
205               env->pregs[PR_CCS],
206               env->cc_op, env->cc_mask);
207         /* We loose the btarget, btaken state here so rexec the
208            branch.  */
209         env->pregs[PR_ERP] -= env->dslot;
210         /* Exception starts with dslot cleared.  */
211         env->dslot = 0;
212     }
213 
214     if (env->pregs[PR_CCS] & U_FLAG) {
215         /* Swap stack pointers.  */
216         env->pregs[PR_USP] = env->regs[R_SP];
217         env->regs[R_SP] = env->ksp;
218     }
219 
220     /* Apply the CRIS CCS shift. Clears U if set.  */
221     cris_shift_ccs(env);
222 
223     /* Now that we are in kernel mode, load the handlers address.
224        This load may not fault, real hw leaves that behaviour as
225        undefined.  */
226     env->pc = cpu_ldl_code(env, env->pregs[PR_EBP] + ex_vec * 4);
227 
228     /* Clear the excption_index to avoid spurious hw_aborts for recursive
229        bus faults.  */
230     cs->exception_index = -1;
231 
232     D_LOG("%s isr=%x vec=%x ccs=%x pid=%d erp=%x\n",
233           __func__, env->pc, ex_vec,
234           env->pregs[PR_CCS],
235           env->pregs[PR_PID],
236           env->pregs[PR_ERP]);
237 }
238 
239 hwaddr cris_cpu_get_phys_page_debug(CPUState *cs, vaddr addr)
240 {
241     CRISCPU *cpu = CRIS_CPU(cs);
242     uint32_t phy = addr;
243     struct cris_mmu_result res;
244     int miss;
245 
246     miss = cris_mmu_translate(&res, &cpu->env, addr, MMU_DATA_LOAD, 0, 1);
247     /* If D TLB misses, try I TLB.  */
248     if (miss) {
249         miss = cris_mmu_translate(&res, &cpu->env, addr, MMU_INST_FETCH, 0, 1);
250     }
251 
252     if (!miss) {
253         phy = res.phy;
254     }
255     D(fprintf(stderr, "%s %x -> %x\n", __func__, addr, phy));
256     return phy;
257 }
258 
259 bool cris_cpu_exec_interrupt(CPUState *cs, int interrupt_request)
260 {
261     CPUClass *cc = CPU_GET_CLASS(cs);
262     CPUCRISState *env = cpu_env(cs);
263     bool ret = false;
264 
265     if (interrupt_request & CPU_INTERRUPT_HARD
266         && (env->pregs[PR_CCS] & I_FLAG)
267         && !env->locked_irq) {
268         cs->exception_index = EXCP_IRQ;
269         cc->tcg_ops->do_interrupt(cs);
270         ret = true;
271     }
272     if (interrupt_request & CPU_INTERRUPT_NMI) {
273         unsigned int m_flag_archval;
274         if (env->pregs[PR_VR] < 32) {
275             m_flag_archval = M_FLAG_V10;
276         } else {
277             m_flag_archval = M_FLAG_V32;
278         }
279         if ((env->pregs[PR_CCS] & m_flag_archval)) {
280             cs->exception_index = EXCP_NMI;
281             cc->tcg_ops->do_interrupt(cs);
282             ret = true;
283         }
284     }
285 
286     return ret;
287 }
288