Baoquan He [off-list ref] writes:

ioremap_uc() is only meaningful on old x86-32 systems with the PAT
extension, and on ia64 with its slightly unconventional ioremap()
behavior. So remove the ioremap_uc() definition in architecutures
other than x86 and ia64. These architectures all have asm-generic/io.h
included and will have the default ioremap_uc() definition which
returns NULL.

This changes the existing behaviour, while no need to worry about
any breakage because in the only callsite of ioremap_uc(), code
has been adjusted to eliminate the impact. Please see
atyfb_setup_generic() of drivers/video/fbdev/aty/atyfb_base.c.

If any new invocation of ioremap_uc() need be added, please consider
using ioremap() intead or adding a ARCH specific version if necessary.

Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Baoquan He <redacted>
Cc: linux-alpha@vger.kernel.org
Cc: linux-hexagon@vger.kernel.org
Cc: linux-m68k@lists.linux-m68k.org
Cc: linux-mips@vger.kernel.org
Cc: linux-parisc@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-sh@vger.kernel.org
Cc: sparclinux@vger.kernel.org
---
 Documentation/driver-api/device-io.rst | 9 +++++----
 arch/alpha/include/asm/io.h            | 1 -
 arch/hexagon/include/asm/io.h          | 3 ---
 arch/m68k/include/asm/kmap.h           | 1 -
 arch/mips/include/asm/io.h             | 1 -
 arch/parisc/include/asm/io.h           | 2 --
 arch/powerpc/include/asm/io.h          | 1 -

Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)

cheers