target-alpha: Implement HALT IPR.

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

target-alpha/helper.h

@@ -113,6 +113,7 @@ DEF_HELPER_2(stq_c_phys, i64, i64, i64)
 
 DEF_HELPER_FLAGS_0(tbia, TCG_CALL_CONST, void)
 DEF_HELPER_FLAGS_1(tbis, TCG_CALL_CONST, void, i64)
+DEF_HELPER_1(halt, void, i64);
 #endif
 
 #include "def-helper.h"

target-alpha/op_helper.c

@@ -22,6 +22,7 @@
 #include "host-utils.h"
 #include "softfloat.h"
 #include "helper.h"
+#include "sysemu.h"
 #include "qemu-timer.h"
 
 #define FP_STATUS (env->fp_status)
@@ -1218,6 +1219,15 @@ void helper_tbis(uint64_t p)
 {
     tlb_flush_page(env, p);
 }
+
+void helper_halt(uint64_t restart)
+{
+    if (restart) {
+        qemu_system_reset_request();
+    } else {
+        qemu_system_shutdown_request();
+    }
+}
 #endif
 
 /*****************************************************************************/

target-alpha/translate.c

@@ -1645,6 +1645,11 @@ static ExitStatus gen_mtpr(DisasContext *ctx, int rb, int regno)
         tcg_gen_st32_i64(tmp, cpu_env, offsetof(CPUState, halted));
         return gen_excp(ctx, EXCP_HLT, 0);
 
+    case 252:
+        /* HALT */
+        gen_helper_halt(tmp);
+        return EXIT_PC_STALE;
+
     default:
         /* The basic registers are data only, and unknown registers
            are read-zero, write-ignore.  */