target-s390: Reorg exception handling

Make the user path more like the system path.  Prepare for more kinds
of runtime exceptions.  Rename ILC to ILEN to make it clear that we
want to pass around a full instruction length, rather than a "code"
that happens to be stored one bit left in a larger field.

Signed-off-by: Richard Henderson <rth@twiddle.net>

1 files changed, 28 insertions, 30 deletions

diff --git a/target-s390x/helper.c b/target-s390x/helper.c
index 7dc4d46..9a132e6 100644
--- a/target-s390x/helper.c
+++ b/target-s390x/helper.c
@@ -99,10 +99,10 @@ void do_interrupt(CPUS390XState *env)
 int cpu_s390x_handle_mmu_fault(CPUS390XState *env, target_ulong address,
                                int rw, int mmu_idx)
 {
-    /* fprintf(stderr, "%s: address 0x%lx rw %d mmu_idx %d\n",
-       __func__, address, rw, mmu_idx); */
-    env->exception_index = EXCP_ADDR;
-    /* FIXME: find out how this works on a real machine */
+    env->exception_index = EXCP_PGM;
+    env->int_pgm_code = PGM_ADDRESSING;
+    /* On real machines this value is dropped into LowMem.  Since this
+       is userland, simply put this someplace that cpu_loop can find it.  */
     env->__excp_addr = address;
     return 1;
 }
@@ -111,11 +111,11 @@ int cpu_s390x_handle_mmu_fault(CPUS390XState *env, target_ulong address,
 
 /* Ensure to exit the TB after this call! */
 static void trigger_pgm_exception(CPUS390XState *env, uint32_t code,
-                                  uint32_t ilc)
+                                  uint32_t ilen)
 {
     env->exception_index = EXCP_PGM;
     env->int_pgm_code = code;
-    env->int_pgm_ilc = ilc;
+    env->int_pgm_ilen = ilen;
 }
 
 static int trans_bits(CPUS390XState *env, uint64_t mode)
@@ -143,30 +143,30 @@ static int trans_bits(CPUS390XState *env, uint64_t mode)
 static void trigger_prot_fault(CPUS390XState *env, target_ulong vaddr,
                                uint64_t mode)
 {
-    int ilc = ILC_LATER_INC_2;
+    int ilen = ILEN_LATER_INC;
     int bits = trans_bits(env, mode) | 4;
 
     DPRINTF("%s: vaddr=%016" PRIx64 " bits=%d\n", __func__, vaddr, bits);
 
     stq_phys(env->psa + offsetof(LowCore, trans_exc_code), vaddr | bits);
-    trigger_pgm_exception(env, PGM_PROTECTION, ilc);
+    trigger_pgm_exception(env, PGM_PROTECTION, ilen);
 }
 
 static void trigger_page_fault(CPUS390XState *env, target_ulong vaddr,
                                uint32_t type, uint64_t asc, int rw)
 {
-    int ilc = ILC_LATER;
+    int ilen = ILEN_LATER;
     int bits = trans_bits(env, asc);
 
+    /* Code accesses have an undefined ilc.  */
     if (rw == 2) {
-        /* code has is undefined ilc */
-        ilc = 2;
+        ilen = 2;
     }
 
     DPRINTF("%s: vaddr=%016" PRIx64 " bits=%d\n", __func__, vaddr, bits);
 
     stq_phys(env->psa + offsetof(LowCore, trans_exc_code), vaddr | bits);
-    trigger_pgm_exception(env, type, ilc);
+    trigger_pgm_exception(env, type, ilen);
 }
 
 static int mmu_translate_asce(CPUS390XState *env, target_ulong vaddr,
@@ -406,7 +406,7 @@ int cpu_s390x_handle_mmu_fault(CPUS390XState *env, target_ulong orig_vaddr,
     if (raddr > (ram_size + virtio_size)) {
         DPRINTF("%s: aaddr %" PRIx64 " > ram_size %" PRIx64 "\n", __func__,
                 (uint64_t)aaddr, (uint64_t)ram_size);
-        trigger_pgm_exception(env, PGM_ADDRESSING, ILC_LATER);
+        trigger_pgm_exception(env, PGM_ADDRESSING, ILEN_LATER);
         return 1;
     }
 
@@ -480,9 +480,9 @@ static void do_svc_interrupt(CPUS390XState *env)
     lowcore = cpu_physical_memory_map(env->psa, &len, 1);
 
     lowcore->svc_code = cpu_to_be16(env->int_svc_code);
-    lowcore->svc_ilc = cpu_to_be16(env->int_svc_ilc);
+    lowcore->svc_ilen = cpu_to_be16(env->int_svc_ilen);
     lowcore->svc_old_psw.mask = cpu_to_be64(get_psw_mask(env));
-    lowcore->svc_old_psw.addr = cpu_to_be64(env->psw.addr + (env->int_svc_ilc));
+    lowcore->svc_old_psw.addr = cpu_to_be64(env->psw.addr + env->int_svc_ilen);
     mask = be64_to_cpu(lowcore->svc_new_psw.mask);
     addr = be64_to_cpu(lowcore->svc_new_psw.addr);
 
@@ -496,28 +496,26 @@ static void do_program_interrupt(CPUS390XState *env)
     uint64_t mask, addr;
     LowCore *lowcore;
     hwaddr len = TARGET_PAGE_SIZE;
-    int ilc = env->int_pgm_ilc;
+    int ilen = env->int_pgm_ilen;
 
-    switch (ilc) {
-    case ILC_LATER:
-        ilc = get_ilc(cpu_ldub_code(env, env->psw.addr));
-        break;
-    case ILC_LATER_INC:
-        ilc = get_ilc(cpu_ldub_code(env, env->psw.addr));
-        env->psw.addr += ilc * 2;
+    switch (ilen) {
+    case ILEN_LATER:
+        ilen = get_ilen(cpu_ldub_code(env, env->psw.addr));
         break;
-    case ILC_LATER_INC_2:
-        ilc = get_ilc(cpu_ldub_code(env, env->psw.addr)) * 2;
-        env->psw.addr += ilc;
+    case ILEN_LATER_INC:
+        ilen = get_ilen(cpu_ldub_code(env, env->psw.addr));
+        env->psw.addr += ilen;
         break;
+    default:
+        assert(ilen == 2 || ilen == 4 || ilen == 6);
     }
 
-    qemu_log_mask(CPU_LOG_INT, "%s: code=0x%x ilc=%d\n",
-                  __func__, env->int_pgm_code, ilc);
+    qemu_log_mask(CPU_LOG_INT, "%s: code=0x%x ilen=%d\n",
+                  __func__, env->int_pgm_code, ilen);
 
     lowcore = cpu_physical_memory_map(env->psa, &len, 1);
 
-    lowcore->pgm_ilc = cpu_to_be16(ilc);
+    lowcore->pgm_ilen = cpu_to_be16(ilen);
     lowcore->pgm_code = cpu_to_be16(env->int_pgm_code);
     lowcore->program_old_psw.mask = cpu_to_be64(get_psw_mask(env));
     lowcore->program_old_psw.addr = cpu_to_be64(env->psw.addr);
@@ -527,7 +525,7 @@ static void do_program_interrupt(CPUS390XState *env)
     cpu_physical_memory_unmap(lowcore, len, 1, len);
 
     DPRINTF("%s: %x %x %" PRIx64 " %" PRIx64 "\n", __func__,
-            env->int_pgm_code, ilc, env->psw.mask,
+            env->int_pgm_code, ilen, env->psw.mask,
             env->psw.addr);
 
     load_psw(env, mask, addr);