xref: /openbmc/qemu/target/cris/helper.c (revision f6a51c84)
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 
28 
29 //#define CRIS_HELPER_DEBUG
30 
31 
32 #ifdef CRIS_HELPER_DEBUG
33 #define D(x) x
34 #define D_LOG(...) qemu_log(__VA_ARGS__)
35 #else
36 #define D(x)
37 #define D_LOG(...) do { } while (0)
38 #endif
39 
40 #if defined(CONFIG_USER_ONLY)
41 
42 void cris_cpu_do_interrupt(CPUState *cs)
43 {
44     CRISCPU *cpu = CRIS_CPU(cs);
45     CPUCRISState *env = &cpu->env;
46 
47     cs->exception_index = -1;
48     env->pregs[PR_ERP] = env->pc;
49 }
50 
51 void crisv10_cpu_do_interrupt(CPUState *cs)
52 {
53     cris_cpu_do_interrupt(cs);
54 }
55 
56 int cris_cpu_handle_mmu_fault(CPUState *cs, vaddr address, int rw,
57                               int mmu_idx)
58 {
59     CRISCPU *cpu = CRIS_CPU(cs);
60 
61     cs->exception_index = 0xaa;
62     cpu->env.pregs[PR_EDA] = address;
63     cpu_dump_state(cs, stderr, fprintf, 0);
64     return 1;
65 }
66 
67 #else /* !CONFIG_USER_ONLY */
68 
69 
70 static void cris_shift_ccs(CPUCRISState *env)
71 {
72     uint32_t ccs;
73     /* Apply the ccs shift.  */
74     ccs = env->pregs[PR_CCS];
75     ccs = ((ccs & 0xc0000000) | ((ccs << 12) >> 2)) & ~0x3ff;
76     env->pregs[PR_CCS] = ccs;
77 }
78 
79 int cris_cpu_handle_mmu_fault(CPUState *cs, vaddr address, int rw,
80                               int mmu_idx)
81 {
82     CRISCPU *cpu = CRIS_CPU(cs);
83     CPUCRISState *env = &cpu->env;
84     struct cris_mmu_result res;
85     int prot, miss;
86     int r = -1;
87     target_ulong phy;
88 
89     qemu_log_mask(CPU_LOG_MMU, "%s addr=%" VADDR_PRIx " pc=%x rw=%x\n",
90             __func__, address, env->pc, rw);
91     miss = cris_mmu_translate(&res, env, address & TARGET_PAGE_MASK,
92                               rw, mmu_idx, 0);
93     if (miss) {
94         if (cs->exception_index == EXCP_BUSFAULT) {
95             cpu_abort(cs,
96                       "CRIS: Illegal recursive bus fault."
97                       "addr=%" VADDR_PRIx " rw=%d\n",
98                       address, rw);
99         }
100 
101         env->pregs[PR_EDA] = address;
102         cs->exception_index = EXCP_BUSFAULT;
103         env->fault_vector = res.bf_vec;
104         r = 1;
105     } else {
106         /*
107          * Mask off the cache selection bit. The ETRAX busses do not
108          * see the top bit.
109          */
110         phy = res.phy & ~0x80000000;
111         prot = res.prot;
112         tlb_set_page(cs, address & TARGET_PAGE_MASK, phy,
113                      prot, mmu_idx, TARGET_PAGE_SIZE);
114         r = 0;
115     }
116     if (r > 0) {
117         qemu_log_mask(CPU_LOG_MMU,
118                 "%s returns %d irqreq=%x addr=%" VADDR_PRIx " phy=%x vec=%x"
119                 " pc=%x\n", __func__, r, cs->interrupt_request, address,
120                 res.phy, res.bf_vec, env->pc);
121     }
122     return r;
123 }
124 
125 void crisv10_cpu_do_interrupt(CPUState *cs)
126 {
127     CRISCPU *cpu = CRIS_CPU(cs);
128     CPUCRISState *env = &cpu->env;
129     int ex_vec = -1;
130 
131     D_LOG("exception index=%d interrupt_req=%d\n",
132           cs->exception_index,
133           cs->interrupt_request);
134 
135     if (env->dslot) {
136         /* CRISv10 never takes interrupts while in a delay-slot.  */
137         cpu_abort(cs, "CRIS: Interrupt on delay-slot\n");
138     }
139 
140     assert(!(env->pregs[PR_CCS] & PFIX_FLAG));
141     switch (cs->exception_index) {
142     case EXCP_BREAK:
143         /* These exceptions are genereated by the core itself.
144            ERP should point to the insn following the brk.  */
145         ex_vec = env->trap_vector;
146         env->pregs[PRV10_BRP] = env->pc;
147         break;
148 
149     case EXCP_NMI:
150         /* NMI is hardwired to vector zero.  */
151         ex_vec = 0;
152         env->pregs[PR_CCS] &= ~M_FLAG_V10;
153         env->pregs[PRV10_BRP] = env->pc;
154         break;
155 
156     case EXCP_BUSFAULT:
157         cpu_abort(cs, "Unhandled busfault");
158         break;
159 
160     default:
161         /* The interrupt controller gives us the vector.  */
162         ex_vec = env->interrupt_vector;
163         /* Normal interrupts are taken between
164            TB's.  env->pc is valid here.  */
165         env->pregs[PR_ERP] = env->pc;
166         break;
167     }
168 
169     if (env->pregs[PR_CCS] & U_FLAG) {
170         /* Swap stack pointers.  */
171         env->pregs[PR_USP] = env->regs[R_SP];
172         env->regs[R_SP] = env->ksp;
173     }
174 
175     /* Now that we are in kernel mode, load the handlers address.  */
176     env->pc = cpu_ldl_code(env, env->pregs[PR_EBP] + ex_vec * 4);
177     env->locked_irq = 1;
178     env->pregs[PR_CCS] |= F_FLAG_V10; /* set F.  */
179 
180     qemu_log_mask(CPU_LOG_INT, "%s isr=%x vec=%x ccs=%x pid=%d erp=%x\n",
181                   __func__, env->pc, ex_vec,
182                   env->pregs[PR_CCS],
183                   env->pregs[PR_PID],
184                   env->pregs[PR_ERP]);
185 }
186 
187 void cris_cpu_do_interrupt(CPUState *cs)
188 {
189     CRISCPU *cpu = CRIS_CPU(cs);
190     CPUCRISState *env = &cpu->env;
191     int ex_vec = -1;
192 
193     D_LOG("exception index=%d interrupt_req=%d\n",
194           cs->exception_index,
195           cs->interrupt_request);
196 
197     switch (cs->exception_index) {
198     case EXCP_BREAK:
199         /* These exceptions are genereated by the core itself.
200            ERP should point to the insn following the brk.  */
201         ex_vec = env->trap_vector;
202         env->pregs[PR_ERP] = env->pc;
203         break;
204 
205     case EXCP_NMI:
206         /* NMI is hardwired to vector zero.  */
207         ex_vec = 0;
208         env->pregs[PR_CCS] &= ~M_FLAG_V32;
209         env->pregs[PR_NRP] = env->pc;
210         break;
211 
212     case EXCP_BUSFAULT:
213         ex_vec = env->fault_vector;
214         env->pregs[PR_ERP] = env->pc;
215         break;
216 
217     default:
218         /* The interrupt controller gives us the vector.  */
219         ex_vec = env->interrupt_vector;
220         /* Normal interrupts are taken between
221            TB's.  env->pc is valid here.  */
222         env->pregs[PR_ERP] = env->pc;
223         break;
224     }
225 
226     /* Fill in the IDX field.  */
227     env->pregs[PR_EXS] = (ex_vec & 0xff) << 8;
228 
229     if (env->dslot) {
230         D_LOG("excp isr=%x PC=%x ds=%d SP=%x"
231               " ERP=%x pid=%x ccs=%x cc=%d %x\n",
232               ex_vec, env->pc, env->dslot,
233               env->regs[R_SP],
234               env->pregs[PR_ERP], env->pregs[PR_PID],
235               env->pregs[PR_CCS],
236               env->cc_op, env->cc_mask);
237         /* We loose the btarget, btaken state here so rexec the
238            branch.  */
239         env->pregs[PR_ERP] -= env->dslot;
240         /* Exception starts with dslot cleared.  */
241         env->dslot = 0;
242     }
243 
244     if (env->pregs[PR_CCS] & U_FLAG) {
245         /* Swap stack pointers.  */
246         env->pregs[PR_USP] = env->regs[R_SP];
247         env->regs[R_SP] = env->ksp;
248     }
249 
250     /* Apply the CRIS CCS shift. Clears U if set.  */
251     cris_shift_ccs(env);
252 
253     /* Now that we are in kernel mode, load the handlers address.
254        This load may not fault, real hw leaves that behaviour as
255        undefined.  */
256     env->pc = cpu_ldl_code(env, env->pregs[PR_EBP] + ex_vec * 4);
257 
258     /* Clear the excption_index to avoid spurios hw_aborts for recursive
259        bus faults.  */
260     cs->exception_index = -1;
261 
262     D_LOG("%s isr=%x vec=%x ccs=%x pid=%d erp=%x\n",
263           __func__, env->pc, ex_vec,
264           env->pregs[PR_CCS],
265           env->pregs[PR_PID],
266           env->pregs[PR_ERP]);
267 }
268 
269 hwaddr cris_cpu_get_phys_page_debug(CPUState *cs, vaddr addr)
270 {
271     CRISCPU *cpu = CRIS_CPU(cs);
272     uint32_t phy = addr;
273     struct cris_mmu_result res;
274     int miss;
275 
276     miss = cris_mmu_translate(&res, &cpu->env, addr, 0, 0, 1);
277     /* If D TLB misses, try I TLB.  */
278     if (miss) {
279         miss = cris_mmu_translate(&res, &cpu->env, addr, 2, 0, 1);
280     }
281 
282     if (!miss) {
283         phy = res.phy;
284     }
285     D(fprintf(stderr, "%s %x -> %x\n", __func__, addr, phy));
286     return phy;
287 }
288 #endif
289 
290 bool cris_cpu_exec_interrupt(CPUState *cs, int interrupt_request)
291 {
292     CPUClass *cc = CPU_GET_CLASS(cs);
293     CRISCPU *cpu = CRIS_CPU(cs);
294     CPUCRISState *env = &cpu->env;
295     bool ret = false;
296 
297     if (interrupt_request & CPU_INTERRUPT_HARD
298         && (env->pregs[PR_CCS] & I_FLAG)
299         && !env->locked_irq) {
300         cs->exception_index = EXCP_IRQ;
301         cc->do_interrupt(cs);
302         ret = true;
303     }
304     if (interrupt_request & CPU_INTERRUPT_NMI) {
305         unsigned int m_flag_archval;
306         if (env->pregs[PR_VR] < 32) {
307             m_flag_archval = M_FLAG_V10;
308         } else {
309             m_flag_archval = M_FLAG_V32;
310         }
311         if ((env->pregs[PR_CCS] & m_flag_archval)) {
312             cs->exception_index = EXCP_NMI;
313             cc->do_interrupt(cs);
314             ret = true;
315         }
316     }
317 
318     return ret;
319 }
320