diff --git a/Kernel/Library/IOWindow.cpp b/Kernel/Library/IOWindow.cpp
index b89b94148a..de6d5beddf 100644
--- a/Kernel/Library/IOWindow.cpp
+++ b/Kernel/Library/IOWindow.cpp
@@ -5,6 +5,7 @@
  */
 
 #include <Kernel/Bus/PCI/API.h>
+#include <Kernel/Bus/PCI/BarMapping.h>
 #include <Kernel/Bus/PCI/Definitions.h>
 #include <Kernel/Library/IOWindow.h>
 
@@ -68,24 +69,18 @@ ErrorOr<NonnullOwnPtr<IOWindow>> IOWindow::create_for_pci_device_bar(PCI::Device
 {
     u64 pci_bar_value = PCI::get_BAR(pci_device_identifier, pci_bar);
     auto pci_bar_space_type = PCI::get_BAR_space_type(pci_bar_value);
-    if (pci_bar_space_type == PCI::BARSpaceType::Memory64BitSpace) {
-        // FIXME: In theory, BAR5 cannot be assigned to 64 bit as it is the last one...
-        // however, there might be 64 bit BAR5 for real bare metal hardware, so remove this
-        // if it makes a problem.
-        if (pci_bar == PCI::HeaderType0BaseRegister::BAR5) {
-            return Error::from_errno(EINVAL);
-        }
-        u64 next_pci_bar_value = PCI::get_BAR(pci_device_identifier, static_cast<PCI::HeaderType0BaseRegister>(to_underlying(pci_bar) + 1));
-        pci_bar_value |= next_pci_bar_value << 32;
-    }
-
-    auto pci_bar_space_size = PCI::get_BAR_space_size(pci_device_identifier, pci_bar);
-    if (pci_bar_space_size < space_length)
-        return Error::from_errno(EIO);
 
     if (pci_bar_space_type == PCI::BARSpaceType::IOSpace) {
 #if ARCH(X86_64)
-        if (Checked<u64>::addition_would_overflow(pci_bar_value, space_length))
+        auto pci_bar_space_size = PCI::get_BAR_space_size(pci_device_identifier, pci_bar);
+        if (pci_bar_space_size < space_length)
+            return Error::from_errno(EIO);
+
+        // X86 IO instructions use DX -a 16 bit register- as the "address"
+        // So we need to check against u16's
+        if (pci_bar_value > AK::NumericLimits<u16>::max())
+            return Error::from_errno(EOVERFLOW);
+        if (Checked<u16>::addition_would_overflow(static_cast<u16>(pci_bar_value), static_cast<u16>(space_length)))
             return Error::from_errno(EOVERFLOW);
         auto io_address_range = TRY(adopt_nonnull_own_or_enomem(new (nothrow) IOAddressData((pci_bar_value & 0xfffffffc), space_length)));
         return TRY(adopt_nonnull_own_or_enomem(new (nothrow) IOWindow(move(io_address_range))));
@@ -95,13 +90,7 @@ ErrorOr<NonnullOwnPtr<IOWindow>> IOWindow::create_for_pci_device_bar(PCI::Device
 #endif
     }
 
-    if (pci_bar_space_type == PCI::BARSpaceType::Memory32BitSpace && Checked<u32>::addition_would_overflow(pci_bar_value, space_length))
-        return Error::from_errno(EOVERFLOW);
-    if (pci_bar_space_type == PCI::BARSpaceType::Memory16BitSpace && Checked<u16>::addition_would_overflow(pci_bar_value, space_length))
-        return Error::from_errno(EOVERFLOW);
-    if (pci_bar_space_type == PCI::BARSpaceType::Memory64BitSpace && Checked<u64>::addition_would_overflow(pci_bar_value, space_length))
-        return Error::from_errno(EOVERFLOW);
-    auto memory_mapped_range = TRY(Memory::adopt_new_nonnull_own_typed_mapping<u8 volatile>(PhysicalAddress(pci_bar_value & PCI::bar_address_mask), space_length, Memory::Region::Access::ReadWrite));
+    auto memory_mapped_range = TRY(PCI::adopt_new_nonnull_own_bar_mapping<u8 volatile>(pci_device_identifier, pci_bar, space_length));
     return TRY(adopt_nonnull_own_or_enomem(new (nothrow) IOWindow(move(memory_mapped_range))));
 }