Use DEFINE_SHOW_ATTRIBUTE helper macro to simplify the code.

Signed-off-by: Liu Shixin <liushixin2@huawei.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

When calling debugfs functions, there is no need to ever check the
return value.  The function can work or not, but the code logic should
never do something different based on this.

Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Burton <paul.burton@mips.com>
Cc: James Hogan <jhogan@kernel.org>
Cc: Yangtao Li <tiny.windzz@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Mathieu Malaterre <malat@debian.org>
Cc: Huacai Chen <chenhc@lemote.com>
Cc: Marcin Nowakowski <marcin.nowakowski@mips.com>
Cc: Yasha Cherikovsky <yasha.che3@gmail.com>
Cc: linux-mips@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Paul Burton <paul.burton@mips.com>

Currently the debugfs interface to print the segment configuration
refuses to print the physical address of mapped segments. However if the
EU bit is set these become unmapped at error level (when
CP0_Status.ERL=1), so the physical address is still relevant.

Update the logic to print the physical address of mapped segments when
the EU bit is set, while still hiding the Cache Coherency Attribute
(since EU overrides that to uncached when ERL=1 too).

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13833/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

We have many extern declarations of mips_debugfs_dir through arch/mips/
in various C files. Unify them by declaring mips_debugfs_dir in a
header, including it in each affected C file & removing the duplicate
declarations.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: Steven J. Hill <Steven.Hill@imgtec.com>
Cc: Alexander Sverdlin <alexander.sverdlin@nokia.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Cc: Maciej W. Rozycki <macro@linux-mips.org>
Cc: linux-kernel@vger.kernel.org
Cc: Joe Perches <joe@perches.com>
Cc: Jaedon Shin <jaedon.shin@gmail.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: David Daney <david.daney@cavium.com>
Cc: Zubair Lutfullah Kakakhel <Zubair.Kakakhel@imgtec.com>
Cc: Markos Chandras <markos.chandras@imgtec.com>
Cc: James Cowgill <James.Cowgill@imgtec.com>
Patchwork: https://patchwork.linux-mips.org/patch/11181/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

Add a new mips/segments debugfs file to print the 6 segmentation
control registers for supported cores. A sample from a proAptiv core
is given below:

Signed-off-by: John Crispin <blogic@openwrt.org>
Patchwork: http://patchwork.linux-mips.org/patch/6137/
Segment   Virtual    Size   Access Mode   Physical   Caching   EU
-------   -------    ----   -----------   --------   -------   --
   0      e0000000   512M      MK           UND         U       0
   1      c0000000   512M      MSK          UND         U       0
   2      a0000000   512M      UK           000         2       0
   3      80000000   512M      UK           000         3       0
   4      40000000    1G       MUSK         UND         U       1
   5      00000000    1G       MUSK         UND         U       1

Reviewed-by: James Hogan <james.hogan@imgtec.com>
Signed-off-by: Steven J. Hill <Steven.Hill@imgtec.com>
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>