For our upstream brcm80211 drivers we build for a number of 
architectures including MIPS. In recent builds we get an error/warning:

   CC [M]  drivers/net/wireless/brcm80211/brcmfmac/cfg80211.o
In file included from ./arch/mips/include/asm/io.h:27:0,
                  from ./arch/mips/include/asm/page.h:176,
                  from include/linux/mm_types.h:15,
                  from include/linux/kmemcheck.h:4,
                  from include/linux/skbuff.h:18,
                  from include/linux/if_ether.h:23,
                  from include/linux/etherdevice.h:25,
                  from 
drivers/net/wireless/brcm80211/brcmfmac/cfg80211.c:20:
./arch/mips/include/asm/pgtable-bits.h:164:0: error: 
"_PAGE_GLOBAL_SHIFT" redefined [-Werror]
./arch/mips/include/asm/pgtable-bits.h:141:0: note: this is the location 
of the previous definition

As it is likely a Kconfig issue I have attached the config file that was 
used for the build. I started out with mips_config.old and ran 'make 
oldconfig' and just hit enter a couple of times selecting all defaults 
which ends up with the mips_config file having the issue. As I have no 
clue what Kconfig combinations are valid I am hoping anyone on the mips 
list can shed some light on this.

Regards,
Arend