target/m68k: use EXCP_ILLEGAL instead of EXCP_UNSUPPORTED

Coldfire defines an "Unsupported instruction" exception if execution
of a valid instruction is attempted but the required hardware is not
present in the processor.

We use it with instructions that are in fact undefined or illegal,
and the exception expected in this case by the kernel is the
illegal exception, so this patch fixes that.

Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20181030165554.5761-1-laurent@vivier.eu>

linux-user/m68k/cpu_loop.c

@@ -55,7 +55,6 @@ void cpu_loop(CPUM68KState *env)
             break;
         case EXCP_LINEA:
         case EXCP_LINEF:
-        case EXCP_UNSUPPORTED:
         do_sigill:
             info.si_signo = TARGET_SIGILL;
             info.si_errno = 0;

target/m68k/cpu.h

@@ -70,7 +70,6 @@
 #define EXCP_MMU_CONF       56  /* MMU Configuration Error */
 #define EXCP_MMU_ILLEGAL    57  /* MMU Illegal Operation Error */
 #define EXCP_MMU_ACCESS     58  /* MMU Access Level Violation Error */
-#define EXCP_UNSUPPORTED    61
 
 #define EXCP_RTE            0x100
 #define EXCP_HALT_INSN      0x101

target/m68k/translate.c

@@ -1553,7 +1553,7 @@ DISAS_INSN(undef)
        but actually illegal for CPU32 or pre-68020.  */
     qemu_log_mask(LOG_UNIMP, "Illegal instruction: %04x @ %08x\n",
                   insn, s->base.pc_next);
-    gen_exception(s, s->base.pc_next, EXCP_UNSUPPORTED);
+    gen_exception(s, s->base.pc_next, EXCP_ILLEGAL);
 }
 
 DISAS_INSN(mulw)
@@ -2800,7 +2800,7 @@ DISAS_INSN(mull)
 
     if (ext & 0x400) {
         if (!m68k_feature(s->env, M68K_FEATURE_QUAD_MULDIV)) {
-            gen_exception(s, s->base.pc_next, EXCP_UNSUPPORTED);
+            gen_exception(s, s->base.pc_next, EXCP_ILLEGAL);
             return;
         }
 
@@ -4510,7 +4510,7 @@ DISAS_INSN(strldsr)
     addr = s->pc - 2;
     ext = read_im16(env, s);
     if (ext != 0x46FC) {
-        gen_exception(s, addr, EXCP_UNSUPPORTED);
+        gen_exception(s, addr, EXCP_ILLEGAL);
         return;
     }
     ext = read_im16(env, s);