mm, show_mem: suppress page counts in non-blockable contexts

On large systems with a lot of memory, walking all RAM to determine page
types may take a half second or even more.

In non-blockable contexts, the page allocator will emit a page allocation
failure warning unless __GFP_NOWARN is specified.  In such contexts, irqs
are typically disabled and such a lengthy delay may even result in NMI
watchdog timeouts.

To fix this, suppress the page walk in such contexts when printing the
page allocation failure warning.

Signed-off-by: David Rientjes <rientjes@google.com>
Cc: Mel Gorman <mgorman@suse.de>
Acked-by: Michal Hocko <mhocko@suse.cz>
Cc: Dave Hansen <dave@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
ARM: Allow arm_memblock_steal() to remove memory from any RAM region

Allow arm_memblock_steal() to remove memory from any RAM region,
including highmem areas.  This allows memory to be stolen from the
very top of declared memory, including highmem areas, rather than
our precious lowmem.

Change-Id: Ib4dbc4e7bc34d402134d96db5ed8118eaffa0245
Acked-by: Sascha Hauer <s.hauer@pengutronix.de>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Git-commit: 7ac68a4c1de6aac5b0bb231fe6d8505ebe5686d9
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Signed-off-by: Larry Bassel <lbassel@codeaurora.org>
Signed-off-by: Francisco Franco <franciscofranco.1990@gmail.com>
ARM: mm: fix type of the arm_dma_limit global variable

arm_dma_limit stores physical address of maximal address accessible by DMA,
so the phys_addr_t type makes much more sense for it instead of u32. This
patch fixes the following build warning:

arch/arm/mm/init.c:380: warning: comparison of distinct pointer types lacks a cast

Reported-by: Russell King <linux@arm.linux.org.uk>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>