target-cris/helper.c

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