CONFIG_ARM64 is not available for thedefaultarchitecture x86.
Result is shown for architecture arm64

CONFIG_ARM64 (not configurable)

modulename: pci-thunder-ecam.ko

and/or

pci-thunder-pem.ko

and/or

pci-xgene.ko

and/or

pcie-hisi.ko

configname: CONFIG_ARM64

Linux Kernel Configuration
└─>ARM64
In linux kernel since version 3.1 (release Date: 2011-10-24)  
ARM 64-bit (AArch64) Linux support.

source code:
drivers/pci/host/pci-thunder-ecam.c
selects
CONFIG_ACPI_CCA_REQUIRED
CONFIG_ACPI_GENERIC_GSI
CONFIG_ACPI_GTDT
CONFIG_ACPI_IORT
CONFIG_ACPI_REDUCED_HARDWARE_ONLY
CONFIG_ACPI_MCFG
CONFIG_ACPI_SPCR_TABLE
CONFIG_ARCH_CLOCKSOURCE_DATA
CONFIG_ARCH_HAS_DEBUG_VIRTUAL
CONFIG_ARCH_HAS_DEVMEM_IS_ALLOWED
CONFIG_ARCH_HAS_ACPI_TABLE_UPGRADE
CONFIG_ARCH_HAS_ELF_RANDOMIZE
CONFIG_ARCH_HAS_FORTIFY_SOURCE
CONFIG_ARCH_HAS_GCOV_PROFILE_ALL
CONFIG_ARCH_HAS_GIGANTIC_PAGE
CONFIG_ARCH_HAS_KCOV
CONFIG_ARCH_HAS_SET_MEMORY
CONFIG_ARCH_HAS_SG_CHAIN
CONFIG_ARCH_HAS_STRICT_KERNEL_RWX
CONFIG_ARCH_HAS_STRICT_MODULE_RWX
CONFIG_ARCH_HAS_TICK_BROADCAST
CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG
CONFIG_ARCH_USE_CMPXCHG_LOCKREF
CONFIG_ARCH_SUPPORTS_MEMORY_FAILURE
CONFIG_ARCH_SUPPORTS_ATOMIC_RMW
CONFIG_ARCH_SUPPORTS_NUMA_BALANCING
CONFIG_ARCH_WANT_COMPAT_IPC_PARSE_VERSION
CONFIG_ARCH_WANT_FRAME_POINTERS
CONFIG_ARCH_HAS_UBSAN_SANITIZE_ALL
CONFIG_ARM_AMBA
CONFIG_ARM_ARCH_TIMER
CONFIG_ARM_GIC
CONFIG_AUDIT_ARCH_COMPAT_GENERIC
CONFIG_ARM_GIC_V2M
CONFIG_ARM_GIC_V3
CONFIG_ARM_GIC_V3_ITS
CONFIG_ARM_PSCI_FW
CONFIG_BUILDTIME_EXTABLE_SORT
CONFIG_CLONE_BACKWARDS
CONFIG_COMMON_CLK
CONFIG_CPU_PM
CONFIG_DCACHE_WORD_ACCESS
CONFIG_EDAC_SUPPORT
CONFIG_FRAME_POINTER
CONFIG_GENERIC_ALLOCATOR
CONFIG_GENERIC_ARCH_TOPOLOGY
CONFIG_GENERIC_CLOCKEVENTS
CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
CONFIG_GENERIC_CPU_AUTOPROBE
CONFIG_GENERIC_EARLY_IOREMAP
CONFIG_GENERIC_IDLE_POLL_SETUP
CONFIG_GENERIC_IRQ_PROBE
CONFIG_GENERIC_IRQ_SHOW
CONFIG_GENERIC_IRQ_SHOW_LEVEL
CONFIG_GENERIC_PCI_IOMAP
CONFIG_GENERIC_SCHED_CLOCK
CONFIG_GENERIC_SMP_IDLE_THREAD
CONFIG_GENERIC_STRNCPY_FROM_USER
CONFIG_GENERIC_STRNLEN_USER
CONFIG_GENERIC_TIME_VSYSCALL
CONFIG_HANDLE_DOMAIN_IRQ
CONFIG_HARDIRQS_SW_RESEND
CONFIG_HAVE_ACPI_APEI
CONFIG_HAVE_ALIGNED_STRUCT_PAGE
CONFIG_HAVE_ARCH_AUDITSYSCALL
CONFIG_HAVE_ARCH_BITREVERSE
CONFIG_HAVE_ARCH_HUGE_VMAP
CONFIG_HAVE_ARCH_JUMP_LABEL
CONFIG_HAVE_ARCH_KASAN
CONFIG_HAVE_ARCH_KGDB
CONFIG_HAVE_ARCH_MMAP_RND_BITS
CONFIG_HAVE_ARCH_MMAP_RND_COMPAT_BITS
CONFIG_HAVE_ARCH_SECCOMP_FILTER
CONFIG_HAVE_ARCH_TRACEHOOK
CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE
CONFIG_HAVE_ARCH_VMAP_STACK
CONFIG_HAVE_ARM_SMCCC
CONFIG_HAVE_EBPF_JIT
CONFIG_HAVE_C_RECORDMCOUNT
CONFIG_HAVE_CC_STACKPROTECTOR
CONFIG_HAVE_CMPXCHG_DOUBLE
CONFIG_HAVE_CMPXCHG_LOCAL
CONFIG_HAVE_CONTEXT_TRACKING
CONFIG_HAVE_DEBUG_BUGVERBOSE
CONFIG_HAVE_DEBUG_KMEMLEAK
CONFIG_HAVE_DMA_API_DEBUG
CONFIG_HAVE_DMA_CONTIGUOUS
CONFIG_HAVE_DYNAMIC_FTRACE
CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
CONFIG_HAVE_FTRACE_MCOUNT_RECORD
CONFIG_HAVE_FUNCTION_TRACER
CONFIG_HAVE_FUNCTION_GRAPH_TRACER
CONFIG_HAVE_GCC_PLUGINS
CONFIG_HAVE_GENERIC_DMA_COHERENT
CONFIG_HAVE_HW_BREAKPOINT
CONFIG_HAVE_IRQ_TIME_ACCOUNTING
CONFIG_HAVE_MEMBLOCK
CONFIG_HAVE_MEMBLOCK_NODE_MAP
CONFIG_HAVE_NMI
CONFIG_HAVE_PATA_PLATFORM
CONFIG_HAVE_PERF_EVENTS
CONFIG_HAVE_PERF_REGS
CONFIG_HAVE_PERF_USER_STACK_DUMP
CONFIG_HAVE_REGS_AND_STACK_ACCESS_API
CONFIG_HAVE_RCU_TABLE_FREE
CONFIG_HAVE_SYSCALL_TRACEPOINTS
CONFIG_HAVE_KPROBES
CONFIG_HAVE_KRETPROBES
CONFIG_IOMMU_DMA
CONFIG_IRQ_DOMAIN
CONFIG_IRQ_FORCED_THREADING
CONFIG_MODULES_USE_ELF_RELA
CONFIG_NO_BOOTMEM
CONFIG_OF
CONFIG_OF_EARLY_FLATTREE
CONFIG_OF_RESERVED_MEM
CONFIG_PCI_ECAM
CONFIG_POWER_RESET
CONFIG_POWER_SUPPLY
CONFIG_SPARSE_IRQ
CONFIG_SYSCTL_EXCEPTION_TRACE
CONFIG_THREAD_INFO_IN_TASK