On some platforms where no separate I/O space exists, there are I/O
hosts which can not be accessed in MMIO mode. Using the logical PIO
mechanism, the host-local I/O resource can be mapped into system
- logic PIO space shared with MMIO hosts, such as PCI/PCIE, then the
- system can access the I/O devices with the mapped logic PIO through
+ logic PIO space shared with MMIO hosts, such as PCI/PCIe, then the
+ system can access the I/O devices with the mapped-logic PIO through
I/O accessors.
+
This way has relatively little I/O performance cost. Please make
sure your devices really need this configure item enabled.