On Wed, Nov 8, 2017 at 11:16 AM, Arnd Bergmann [off-list ref] wrote:

On Wed, Nov 8, 2017 at 6:55 AM, Greentime Hu [off-list ref] wrote:

quoted

--- /dev/null
+++ b/arch/nds32/Kconfig

@@ -0,0 +1,107 @@
+#
+# For a description of the syntax of this configuration file,
+# see Documentation/kbuild/kconfig-language.txt.
+#
+
+config NDS32
+        def_bool y
+       select ARCH_HAS_RAW_COPY_USER
+       select ARCH_WANT_FRAME_POINTERS if FTRACE
+       select ARCH_WANT_IPC_PARSE_VERSION
+       select CLKSRC_MMIO
+       select CLONE_BACKWARDS
+       select TIMER_OF
+       select FRAME_POINTER
+       select GENERIC_ATOMIC64
+       select GENERIC_CPU_DEVICES
+       select GENERIC_CLOCKEVENTS
+       select GENERIC_IOMAP
+       select GENERIC_IRQ_CHIP
+       select GENERIC_IRQ_PROBE
+       select GENERIC_IRQ_SHOW
+       select GENERIC_STRNCPY_FROM_USER
+       select GENERIC_STRNLEN_USER
+       select GENERIC_TIME_VSYSCALL
+       select HAVE_ARCH_TRACEHOOK
+       select HAVE_GENERIC_IOMAP

You normally don't want HAVE_GENERIC_IOMAP, at least unless the CPU
has special instructions to trigger PCI I/O port access.

GENERIC_IOMAP or HAVE_GENERIC_IOMAP?

The latter doesn't even exist, except in
Documentation/kbuild/kconfig-language.txt, so it cannot be selected.

Given the checks for __NDS32_EB__, NDS32 can be either big or little endian,
so you should have (excatly one of) CPU_BIG_ENDIAN or CPU_LITTLE_ENDIAN set.

Gr{oetje,eeting}s,

                        Geert