i386/pc: factor out above-4g end to an helper

There's a couple of places that seem to duplicate this calculation
of RAM size above the 4G boundary. Move all those to a helper function.

Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Message-Id: <20220719170014.27028-5-joao.m.martins@oracle.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

hw/i386/pc.c

@@ -814,6 +814,17 @@ void xen_load_linux(PCMachineState *pcms)
 #define PC_ROM_ALIGN       0x800
 #define PC_ROM_SIZE        (PC_ROM_MAX - PC_ROM_MIN_VGA)
 
+static hwaddr pc_above_4g_end(PCMachineState *pcms)
+{
+    X86MachineState *x86ms = X86_MACHINE(pcms);
+
+    if (pcms->sgx_epc.size != 0) {
+        return sgx_epc_above_4g_end(&pcms->sgx_epc);
+    }
+
+    return x86ms->above_4g_mem_start + x86ms->above_4g_mem_size;
+}
+
 void pc_memory_init(PCMachineState *pcms,
                     MemoryRegion *system_memory,
                     MemoryRegion *rom_memory,
@@ -891,15 +902,8 @@ void pc_memory_init(PCMachineState *pcms,
             exit(EXIT_FAILURE);
         }
 
-        if (pcms->sgx_epc.size != 0) {
-            machine->device_memory->base = sgx_epc_above_4g_end(&pcms->sgx_epc);
-        } else {
-            machine->device_memory->base =
-                x86ms->above_4g_mem_start + x86ms->above_4g_mem_size;
-        }
-
         machine->device_memory->base =
-            ROUND_UP(machine->device_memory->base, 1 * GiB);
+            ROUND_UP(pc_above_4g_end(pcms), 1 * GiB);
 
         if (pcmc->enforce_aligned_dimm) {
             /* size device region assuming 1G page max alignment per slot */
@@ -926,10 +930,8 @@ void pc_memory_init(PCMachineState *pcms,
         if (pcmc->has_reserved_memory && machine->device_memory->base) {
             cxl_base = machine->device_memory->base
                 + memory_region_size(&machine->device_memory->mr);
-        } else if (pcms->sgx_epc.size != 0) {
-            cxl_base = sgx_epc_above_4g_end(&pcms->sgx_epc);
         } else {
-            cxl_base = x86ms->above_4g_mem_start + x86ms->above_4g_mem_size;
+            cxl_base = pc_above_4g_end(pcms);
         }
 
         e820_add_entry(cxl_base, cxl_size, E820_RESERVED);
@@ -1016,7 +1018,6 @@ uint64_t pc_pci_hole64_start(void)
     PCMachineState *pcms = PC_MACHINE(qdev_get_machine());
     PCMachineClass *pcmc = PC_MACHINE_GET_CLASS(pcms);
     MachineState *ms = MACHINE(pcms);
-    X86MachineState *x86ms = X86_MACHINE(pcms);
     uint64_t hole64_start = 0;
 
     if (pcms->cxl_devices_state.host_mr.addr) {
@@ -1034,10 +1035,8 @@ uint64_t pc_pci_hole64_start(void)
         if (!pcmc->broken_reserved_end) {
             hole64_start += memory_region_size(&ms->device_memory->mr);
         }
-    } else if (pcms->sgx_epc.size != 0) {
-            hole64_start = sgx_epc_above_4g_end(&pcms->sgx_epc);
     } else {
-        hole64_start = x86ms->above_4g_mem_start + x86ms->above_4g_mem_size;
+        hole64_start = pc_above_4g_end(pcms);
     }
 
     return ROUND_UP(hole64_start, 1 * GiB);