target-alpha: Move alarm to vm_clock

Basing the alarm off the rtc_clock was silly.  It leads to horrible
spinning in the guest after being suspended and resumed, as it tries
to catch up with lost ticks.

This requires adding an accessor for reading the vm_clock too.
Signed-off-by: NRichard Henderson <rth@twiddle.net>

hw/alpha/typhoon.c

@@ -693,7 +693,7 @@ PCIBus *typhoon_init(ram_addr_t ram_size, ISABus **isa_bus,
         AlphaCPU *cpu = cpus[i];
         s->cchip.cpu[i] = cpu;
         if (cpu != NULL) {
-            cpu->alarm_timer = qemu_new_timer_ns(rtc_clock,
+            cpu->alarm_timer = qemu_new_timer_ns(vm_clock,
                                                  typhoon_alarm_timer,
                                                  (void *)((uintptr_t)s + i));
         }

target-alpha/helper.h

@@ -114,7 +114,8 @@ DEF_HELPER_FLAGS_2(tbis, TCG_CALL_NO_RWG, void, env, i64)
 
 DEF_HELPER_1(halt, void, i64);
 
-DEF_HELPER_FLAGS_0(get_time, TCG_CALL_NO_RWG, i64)
+DEF_HELPER_FLAGS_0(get_vmtime, TCG_CALL_NO_RWG, i64)
+DEF_HELPER_FLAGS_0(get_walltime, TCG_CALL_NO_RWG, i64)
 DEF_HELPER_FLAGS_2(set_alarm, TCG_CALL_NO_RWG, void, env, i64)
 #endif
 

target-alpha/sys_helper.c

@@ -70,7 +70,12 @@ void helper_halt(uint64_t restart)
     }
 }
 
-uint64_t helper_get_time(void)
+uint64_t helper_get_vmtime(void)
+{
+    return qemu_get_clock_ns(vm_clock);
+}
+
+uint64_t helper_get_walltime(void)
 {
     return qemu_get_clock_ns(rtc_clock);
 }

target-alpha/translate.c

@@ -1634,15 +1634,19 @@ static ExitStatus gen_mfpr(int ra, int regno)
         return NO_EXIT;
     }
 
-    if (regno == 250) {
-        /* WALL_TIME */
+    /* Special help for VMTIME and WALLTIME.  */
+    if (regno == 250 || regno == 249) {
+	void (*helper)(TCGv) = gen_helper_get_walltime;
+	if (regno == 249) {
+		helper = gen_helper_get_vmtime;
+	}
         if (use_icount) {
             gen_io_start();
-            gen_helper_get_time(cpu_ir[ra]);
+            helper(cpu_ir[ra]);
             gen_io_end();
             return EXIT_PC_STALE;
         } else {
-            gen_helper_get_time(cpu_ir[ra]);
+            helper(cpu_ir[ra]);
             return NO_EXIT;
         }
     }