unicore32/mm/fault.c: Port OOM changes to do_pf

Commit d065bd810b6deb67d4897a14bfe21f8eb526ba99
(mm: retry page fault when blocking on disk transfer) and
commit 37b23e0525d393d48a7d59f870b3bc061a30ccdb
(x86,mm: make pagefault killable)

The above commits introduced changes into the x86 pagefault handler
for making the page fault handler retryable as well as killable.

These changes reduce the mmap_sem hold time, which is crucial
during OOM killer invocation.

Port these changes to unicore32.

Signed-off-by: Kautuk Consul <consul.kautuk@gmail.com>
Acked-by: Guan Xuetao <gxt@mprc.pku.edu.cn>
UniCore32 bugfix: add missed CONFIG_ZONE_DMA

Because our PCI-bus handler confines dma zone into 128M, we should add
CONFIG_ZONE_DMA for all boards. Otherwise, all memory bigger than 128M
will be pushed into ZONE_MOVABLE.

Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Liu Guoli <liuguoli@mprc.pku.edu.cn>
Signed-off-by: Guan Xuetao <gxt@mprc.pku.edu.cn>
UniCore32-bugfix: fix mismatch return value of __xchg_bad_pointer

When disintegrate system.h, I left an error in asm/cmpxchg.h, which
will result in following error:

arch/unicore32/include/asm/cmpxchg.h: In function '__xchg':
arch/unicore32/include/asm/cmpxchg.h:38: error: void value not ignored as it ought to be

Signed-off-by: Guan Xuetao <gxt@mprc.pku.edu.cn>
UniCore32-bugfix: Remove definitions in asm/bug.h to solve difference between native and cross compiler

For kernel/bound.c being compiled by native compiler, it will generate following errors in gcc 4.4.3:
  CC      kernel/bounds.s
In file included from include/linux/bug.h:4,
                 from include/linux/page-flags.h:9,
                 from kernel/bounds.c:9:
arch/unicore32/include/asm/bug.h:22: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'void'
arch/unicore32/include/asm/bug.h:23: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'void'

So, we moved definitions in asm/bug.h to arch/unicore32/kernel/setup.h to solve the problem.

Signed-off-by: Guan Xuetao <gxt@mprc.pku.edu.cn>
UAPI: (Scripted) Disintegrate arch/unicore32/include/asm

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Michael Kerrisk <mtk.manpages@gmail.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Dave Jones <davej@redhat.com>
unicore32: Use Kbuild infrastructure for kvm_para.h

All the headers but kvm_para.h use the Kbuild infrastructure to
get to the asm-generic headers.

Cc: linux-kbuild@vger.kernel.org
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Guan Xuetao <gxt@mprc.pku.edu.cn>
unicore32: switch to generic kernel_thread()/kernel_execve()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Acked-and-Tested-by: Guan Xuetao <gxt@mprc.pku.edu.cn>
unicore32: switch to generic sys_execve()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Acked-and-Tested-by: Guan Xuetao <gxt@mprc.pku.edu.cn>
arch/unicore32: remove CONFIG_EXPERIMENTAL

This config item has not carried much meaning for a while now and is
almost always enabled by default. As agreed during the Linux kernel
summit, remove it.

CC: Guan Xuetao <gxt@mprc.pku.edu.cn>
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Guan Xuetao <gxt@mprc.pku.edu.cn>