arm: drop intermediate cpu_model -> cpu type parsing and use cpu type directly

there are 2 use cases to deal with:
  1: fixed CPU models per board/soc
  2: boards with user configurable cpu_model and fallback to
     default cpu_model if user hasn't specified one explicitly

For the 1st
  drop intermediate cpu_model parsing and use const cpu type
  directly, which replaces:
     typename = object_class_get_name(
           cpu_class_by_name(TYPE_ARM_CPU, cpu_model))
     object_new(typename)
  with
     object_new(FOO_CPU_TYPE_NAME)
  or
     cpu_generic_init(BASE_CPU_TYPE, "my cpu model")
  with
     cpu_create(FOO_CPU_TYPE_NAME)

as result 1st use case doesn't have to invoke not necessary
translation and not needed code is removed.

For the 2nd
 1: set default cpu type with MachineClass::default_cpu_type and
 2: use generic cpu_model parsing that done before machine_init()
    is run and:
    2.1: drop custom cpu_model parsing where pattern is:
       typename = object_class_get_name(
           cpu_class_by_name(TYPE_ARM_CPU, cpu_model))
       [parse_features(typename, cpu_model, &err) ]

    2.2: or replace cpu_generic_init() which does what
         2.1 does + create_cpu(typename) with just
         create_cpu(machine->cpu_type)
as result cpu_name -> cpu_type translation is done using
generic machine code one including parsing optional features
if supported/present (removes a bunch of duplicated cpu_model
parsing code) and default cpu type is defined in an uniform way
within machine_class_init callbacks instead of adhoc places
in boadr's machine_init code.

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
Message-Id: <1505318697-77161-6-git-send-email-imammedo@redhat.com>
Reviewed-by: Alistair Francis <alistair.francis@xilinx.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
diff --git a/hw/arm/realview.c b/hw/arm/realview.c
index f3a49b6..87cd1e5 100644
--- a/hw/arm/realview.c
+++ b/hw/arm/realview.c
@@ -57,7 +57,6 @@
 {
     ARMCPU *cpu = NULL;
     CPUARMState *env;
-    ObjectClass *cpu_oc;
     MemoryRegion *sysmem = get_system_memory();
     MemoryRegion *ram_lo;
     MemoryRegion *ram_hi = g_new(MemoryRegion, 1);
@@ -98,14 +97,8 @@
         break;
     }
 
-    cpu_oc = cpu_class_by_name(TYPE_ARM_CPU, machine->cpu_model);
-    if (!cpu_oc) {
-        fprintf(stderr, "Unable to find CPU definition\n");
-        exit(1);
-    }
-
     for (n = 0; n < smp_cpus; n++) {
-        Object *cpuobj = object_new(object_class_get_name(cpu_oc));
+        Object *cpuobj = object_new(machine->cpu_type);
 
         /* By default A9,A15 and ARM1176 CPUs have EL3 enabled.  This board
          * does not currently support EL3 so the CPU EL3 property is disabled
@@ -361,33 +354,21 @@
 
 static void realview_eb_init(MachineState *machine)
 {
-    if (!machine->cpu_model) {
-        machine->cpu_model = "arm926";
-    }
     realview_init(machine, BOARD_EB);
 }
 
 static void realview_eb_mpcore_init(MachineState *machine)
 {
-    if (!machine->cpu_model) {
-        machine->cpu_model = "arm11mpcore";
-    }
     realview_init(machine, BOARD_EB_MPCORE);
 }
 
 static void realview_pb_a8_init(MachineState *machine)
 {
-    if (!machine->cpu_model) {
-        machine->cpu_model = "cortex-a8";
-    }
     realview_init(machine, BOARD_PB_A8);
 }
 
 static void realview_pbx_a9_init(MachineState *machine)
 {
-    if (!machine->cpu_model) {
-        machine->cpu_model = "cortex-a9";
-    }
     realview_init(machine, BOARD_PBX_A9);
 }
 
@@ -399,6 +380,7 @@
     mc->init = realview_eb_init;
     mc->block_default_type = IF_SCSI;
     mc->ignore_memory_transaction_failures = true;
+    mc->default_cpu_type = ARM_CPU_TYPE_NAME("arm926");
 }
 
 static const TypeInfo realview_eb_type = {
@@ -416,6 +398,7 @@
     mc->block_default_type = IF_SCSI;
     mc->max_cpus = 4;
     mc->ignore_memory_transaction_failures = true;
+    mc->default_cpu_type = ARM_CPU_TYPE_NAME("arm11mpcore");
 }
 
 static const TypeInfo realview_eb_mpcore_type = {
@@ -431,6 +414,7 @@
     mc->desc = "ARM RealView Platform Baseboard for Cortex-A8";
     mc->init = realview_pb_a8_init;
     mc->ignore_memory_transaction_failures = true;
+    mc->default_cpu_type = ARM_CPU_TYPE_NAME("cortex-a8");
 }
 
 static const TypeInfo realview_pb_a8_type = {
@@ -447,6 +431,7 @@
     mc->init = realview_pbx_a9_init;
     mc->max_cpus = 4;
     mc->ignore_memory_transaction_failures = true;
+    mc->default_cpu_type = ARM_CPU_TYPE_NAME("cortex-a9");
 }
 
 static const TypeInfo realview_pbx_a9_type = {