arm/integratorcp: use memdev for RAM

memory_region_allocate_system_memory() API is going away, so
replace it with memdev allocated MemoryRegion. The later is
initialized by generic code, so board only needs to opt in
to memdev scheme by providing
  MachineClass::default_ram_id
and using MachineState::ram instead of manually initializing
RAM memory region.

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20200219160953.13771-18-imammedo@redhat.com>

hw/arm/integratorcp.c

@@ -585,7 +585,6 @@ static void integratorcp_init(MachineState *machine)
     Object *cpuobj;
     ARMCPU *cpu;
     MemoryRegion *address_space_mem = get_system_memory();
-    MemoryRegion *ram = g_new(MemoryRegion, 1);
     MemoryRegion *ram_alias = g_new(MemoryRegion, 1);
     qemu_irq pic[32];
     DeviceState *dev, *sic, *icp;
@@ -605,14 +604,13 @@ static void integratorcp_init(MachineState *machine)
 
     cpu = ARM_CPU(cpuobj);
 
-    memory_region_allocate_system_memory(ram, NULL, "integrator.ram",
-                                         ram_size);
     /* ??? On a real system the first 1Mb is mapped as SSRAM or boot flash.  */
     /* ??? RAM should repeat to fill physical memory space.  */
     /* SDRAM at address zero*/
-    memory_region_add_subregion(address_space_mem, 0, ram);
+    memory_region_add_subregion(address_space_mem, 0, machine->ram);
     /* And again at address 0x80000000 */
-    memory_region_init_alias(ram_alias, NULL, "ram.alias", ram, 0, ram_size);
+    memory_region_init_alias(ram_alias, NULL, "ram.alias", machine->ram,
+                             0, ram_size);
     memory_region_add_subregion(address_space_mem, 0x80000000, ram_alias);
 
     dev = qdev_create(NULL, TYPE_INTEGRATOR_CM);
@@ -660,6 +658,7 @@ static void integratorcp_machine_init(MachineClass *mc)
     mc->init = integratorcp_init;
     mc->ignore_memory_transaction_failures = true;
     mc->default_cpu_type = ARM_CPU_TYPE_NAME("arm926");
+    mc->default_ram_id = "integrator.ram";
 }
 
 DEFINE_MACHINE("integratorcp", integratorcp_machine_init)