xref: /openbmc/qemu/target/cris/helper.c (revision 6016b7b4)
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 static void cris_shift_ccs(CPUCRISState *env)
43 {
44     uint32_t ccs;
45     /* Apply the ccs shift.  */
46     ccs = env->pregs[PR_CCS];
47     ccs = ((ccs & 0xc0000000) | ((ccs << 12) >> 2)) & ~0x3ff;
48     env->pregs[PR_CCS] = ccs;
49 }
50 
51 bool cris_cpu_tlb_fill(CPUState *cs, vaddr address, int size,
52                        MMUAccessType access_type, int mmu_idx,
53                        bool probe, uintptr_t retaddr)
54 {
55     CRISCPU *cpu = CRIS_CPU(cs);
56     CPUCRISState *env = &cpu->env;
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, true)) {
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     CRISCPU *cpu = CRIS_CPU(cs);
100     CPUCRISState *env = &cpu->env;
101     int ex_vec = -1;
102 
103     D_LOG("exception index=%d interrupt_req=%d\n",
104           cs->exception_index,
105           cs->interrupt_request);
106 
107     if (env->dslot) {
108         /* CRISv10 never takes interrupts while in a delay-slot.  */
109         cpu_abort(cs, "CRIS: Interrupt on delay-slot\n");
110     }
111 
112     assert(!(env->pregs[PR_CCS] & PFIX_FLAG));
113     switch (cs->exception_index) {
114     case EXCP_BREAK:
115         /* These exceptions are genereated by the core itself.
116            ERP should point to the insn following the brk.  */
117         ex_vec = env->trap_vector;
118         env->pregs[PRV10_BRP] = env->pc;
119         break;
120 
121     case EXCP_NMI:
122         /* NMI is hardwired to vector zero.  */
123         ex_vec = 0;
124         env->pregs[PR_CCS] &= ~M_FLAG_V10;
125         env->pregs[PRV10_BRP] = env->pc;
126         break;
127 
128     case EXCP_BUSFAULT:
129         cpu_abort(cs, "Unhandled busfault");
130         break;
131 
132     default:
133         /* The interrupt controller gives us the vector.  */
134         ex_vec = env->interrupt_vector;
135         /* Normal interrupts are taken between
136            TB's.  env->pc is valid here.  */
137         env->pregs[PR_ERP] = env->pc;
138         break;
139     }
140 
141     if (env->pregs[PR_CCS] & U_FLAG) {
142         /* Swap stack pointers.  */
143         env->pregs[PR_USP] = env->regs[R_SP];
144         env->regs[R_SP] = env->ksp;
145     }
146 
147     /* Now that we are in kernel mode, load the handlers address.  */
148     env->pc = cpu_ldl_code(env, env->pregs[PR_EBP] + ex_vec * 4);
149     env->locked_irq = 1;
150     env->pregs[PR_CCS] |= F_FLAG_V10; /* set F.  */
151 
152     qemu_log_mask(CPU_LOG_INT, "%s isr=%x vec=%x ccs=%x pid=%d erp=%x\n",
153                   __func__, env->pc, ex_vec,
154                   env->pregs[PR_CCS],
155                   env->pregs[PR_PID],
156                   env->pregs[PR_ERP]);
157 }
158 
159 void cris_cpu_do_interrupt(CPUState *cs)
160 {
161     CRISCPU *cpu = CRIS_CPU(cs);
162     CPUCRISState *env = &cpu->env;
163     int ex_vec = -1;
164 
165     D_LOG("exception index=%d interrupt_req=%d\n",
166           cs->exception_index,
167           cs->interrupt_request);
168 
169     switch (cs->exception_index) {
170     case EXCP_BREAK:
171         /* These exceptions are genereated by the core itself.
172            ERP should point to the insn following the brk.  */
173         ex_vec = env->trap_vector;
174         env->pregs[PR_ERP] = env->pc;
175         break;
176 
177     case EXCP_NMI:
178         /* NMI is hardwired to vector zero.  */
179         ex_vec = 0;
180         env->pregs[PR_CCS] &= ~M_FLAG_V32;
181         env->pregs[PR_NRP] = env->pc;
182         break;
183 
184     case EXCP_BUSFAULT:
185         ex_vec = env->fault_vector;
186         env->pregs[PR_ERP] = env->pc;
187         break;
188 
189     default:
190         /* The interrupt controller gives us the vector.  */
191         ex_vec = env->interrupt_vector;
192         /* Normal interrupts are taken between
193            TB's.  env->pc is valid here.  */
194         env->pregs[PR_ERP] = env->pc;
195         break;
196     }
197 
198     /* Fill in the IDX field.  */
199     env->pregs[PR_EXS] = (ex_vec & 0xff) << 8;
200 
201     if (env->dslot) {
202         D_LOG("excp isr=%x PC=%x ds=%d SP=%x"
203               " ERP=%x pid=%x ccs=%x cc=%d %x\n",
204               ex_vec, env->pc, env->dslot,
205               env->regs[R_SP],
206               env->pregs[PR_ERP], env->pregs[PR_PID],
207               env->pregs[PR_CCS],
208               env->cc_op, env->cc_mask);
209         /* We loose the btarget, btaken state here so rexec the
210            branch.  */
211         env->pregs[PR_ERP] -= env->dslot;
212         /* Exception starts with dslot cleared.  */
213         env->dslot = 0;
214     }
215 
216     if (env->pregs[PR_CCS] & U_FLAG) {
217         /* Swap stack pointers.  */
218         env->pregs[PR_USP] = env->regs[R_SP];
219         env->regs[R_SP] = env->ksp;
220     }
221 
222     /* Apply the CRIS CCS shift. Clears U if set.  */
223     cris_shift_ccs(env);
224 
225     /* Now that we are in kernel mode, load the handlers address.
226        This load may not fault, real hw leaves that behaviour as
227        undefined.  */
228     env->pc = cpu_ldl_code(env, env->pregs[PR_EBP] + ex_vec * 4);
229 
230     /* Clear the excption_index to avoid spurios hw_aborts for recursive
231        bus faults.  */
232     cs->exception_index = -1;
233 
234     D_LOG("%s isr=%x vec=%x ccs=%x pid=%d erp=%x\n",
235           __func__, env->pc, ex_vec,
236           env->pregs[PR_CCS],
237           env->pregs[PR_PID],
238           env->pregs[PR_ERP]);
239 }
240 
241 hwaddr cris_cpu_get_phys_page_debug(CPUState *cs, vaddr addr)
242 {
243     CRISCPU *cpu = CRIS_CPU(cs);
244     uint32_t phy = addr;
245     struct cris_mmu_result res;
246     int miss;
247 
248     miss = cris_mmu_translate(&res, &cpu->env, addr, MMU_DATA_LOAD, 0, 1);
249     /* If D TLB misses, try I TLB.  */
250     if (miss) {
251         miss = cris_mmu_translate(&res, &cpu->env, addr, MMU_INST_FETCH, 0, 1);
252     }
253 
254     if (!miss) {
255         phy = res.phy;
256     }
257     D(fprintf(stderr, "%s %x -> %x\n", __func__, addr, phy));
258     return phy;
259 }
260 
261 bool cris_cpu_exec_interrupt(CPUState *cs, int interrupt_request)
262 {
263     CPUClass *cc = CPU_GET_CLASS(cs);
264     CRISCPU *cpu = CRIS_CPU(cs);
265     CPUCRISState *env = &cpu->env;
266     bool ret = false;
267 
268     if (interrupt_request & CPU_INTERRUPT_HARD
269         && (env->pregs[PR_CCS] & I_FLAG)
270         && !env->locked_irq) {
271         cs->exception_index = EXCP_IRQ;
272         cc->tcg_ops->do_interrupt(cs);
273         ret = true;
274     }
275     if (interrupt_request & CPU_INTERRUPT_NMI) {
276         unsigned int m_flag_archval;
277         if (env->pregs[PR_VR] < 32) {
278             m_flag_archval = M_FLAG_V10;
279         } else {
280             m_flag_archval = M_FLAG_V32;
281         }
282         if ((env->pregs[PR_CCS] & m_flag_archval)) {
283             cs->exception_index = EXCP_NMI;
284             cc->tcg_ops->do_interrupt(cs);
285             ret = true;
286         }
287     }
288 
289     return ret;
290 }
291