target/ppc: Simplify ppc_booke_xlate() part 1

Move setting error_code that appears in every case out in front and
hoist the common fall through case for BOOKE206 as well which allows
removing the nested switches.

Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: BALATON Zoltan <balaton@eik.bme.hu>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
diff --git a/target/ppc/mmu_common.c b/target/ppc/mmu_common.c
index 09a780b..6110929 100644
--- a/target/ppc/mmu_common.c
+++ b/target/ppc/mmu_common.c
@@ -1220,58 +1220,41 @@
     }
 
     log_cpu_state_mask(CPU_LOG_MMU, cs, 0);
+    env->error_code = 0;
+    if (ret == -1) {
+        if (env->mmu_model == POWERPC_MMU_BOOKE206) {
+            booke206_update_mas_tlb_miss(env, eaddr, access_type, mmu_idx);
+        }
+    }
     if (access_type == MMU_INST_FETCH) {
         switch (ret) {
         case -1:
             /* No matches in page tables or TLB */
-            switch (env->mmu_model) {
-            case POWERPC_MMU_BOOKE206:
-                booke206_update_mas_tlb_miss(env, eaddr, access_type, mmu_idx);
-                /* fall through */
-            case POWERPC_MMU_BOOKE:
-                cs->exception_index = POWERPC_EXCP_ITLB;
-                env->error_code = 0;
-                env->spr[SPR_BOOKE_DEAR] = eaddr;
-                env->spr[SPR_BOOKE_ESR] = mmubooke206_esr(mmu_idx, access_type);
-                break;
-            default:
-                g_assert_not_reached();
-            }
+            cs->exception_index = POWERPC_EXCP_ITLB;
+            env->spr[SPR_BOOKE_DEAR] = eaddr;
+            env->spr[SPR_BOOKE_ESR] = mmubooke206_esr(mmu_idx, access_type);
             break;
         case -2:
             /* Access rights violation */
             cs->exception_index = POWERPC_EXCP_ISI;
-            env->error_code = 0;
             break;
         case -3:
             /* No execute protection violation */
             cs->exception_index = POWERPC_EXCP_ISI;
             env->spr[SPR_BOOKE_ESR] = 0;
-            env->error_code = 0;
             break;
         }
     } else {
         switch (ret) {
         case -1:
             /* No matches in page tables or TLB */
-            switch (env->mmu_model) {
-            case POWERPC_MMU_BOOKE206:
-                booke206_update_mas_tlb_miss(env, eaddr, access_type, mmu_idx);
-                /* fall through */
-            case POWERPC_MMU_BOOKE:
-                cs->exception_index = POWERPC_EXCP_DTLB;
-                env->error_code = 0;
-                env->spr[SPR_BOOKE_DEAR] = eaddr;
-                env->spr[SPR_BOOKE_ESR] = mmubooke206_esr(mmu_idx, access_type);
-                break;
-            default:
-                g_assert_not_reached();
-            }
+            cs->exception_index = POWERPC_EXCP_DTLB;
+            env->spr[SPR_BOOKE_DEAR] = eaddr;
+            env->spr[SPR_BOOKE_ESR] = mmubooke206_esr(mmu_idx, access_type);
             break;
         case -2:
             /* Access rights violation */
             cs->exception_index = POWERPC_EXCP_DSI;
-            env->error_code = 0;
             env->spr[SPR_BOOKE_DEAR] = eaddr;
             env->spr[SPR_BOOKE_ESR] = mmubooke206_esr(mmu_idx, access_type);
             break;