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-rw-r--r--lib/Kconfig16
1 files changed, 16 insertions, 0 deletions
diff --git a/lib/Kconfig b/lib/Kconfig
index e96089499371..5fe577673b98 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -55,6 +55,22 @@ config ARCH_USE_CMPXCHG_LOCKREF
config ARCH_HAS_FAST_MULTIPLIER
bool
+config INDIRECT_PIO
+ bool "Access I/O in non-MMIO mode"
+ depends on ARM64
+ help
+ 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
+ I/O accessors.
+
+ This way has relatively little I/O performance cost. Please make
+ sure your devices really need this configure item enabled.
+
+ When in doubt, say N.
+
config CRC_CCITT
tristate "CRC-CCITT functions"
help