dma-mapping: consolidate dma_{alloc,free}_{attrs,coherent}

Since 2009 we have a nice asm-generic header implementing lots of DMA API
functions for architectures using struct dma_map_ops, but unfortunately
it's still missing a lot of APIs that all architectures still have to
duplicate.

This series consolidates the remaining functions, although we still need
arch opt outs for two of them as a few architectures have very
non-standard implementations.

This patch (of 5):

The coherent DMA allocator works the same over all architectures supporting
dma_map operations.

This patch consolidates them and converges the minor differences:

 - the debug_dma helpers are now called from all architectures, including
   those that were previously missing them
 - dma_alloc_from_coherent and dma_release_from_coherent are now always
   called from the generic alloc/free routines instead of the ops
   dma-mapping-common.h always includes dma-coherent.h to get the defintions
   for them, or the stubs if the architecture doesn't support this feature
 - checks for ->alloc / ->free presence are removed.  There is only one
   magic instead of dma_map_ops without them (mic_dma_ops) and that one
   is x86 only anyway.

Besides that only x86 needs special treatment to replace a default devices
if none is passed and tweak the gfp_flags.  An optional arch hook is provided
for that.

[linux@roeck-us.net: fix build]
[jcmvbkbc@gmail.com: fix xtensa]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --cc arch/alpha/include/asm/dma-mapping.h
Simple merge

diff --cc arch/arm/include/asm/dma-mapping.h
Simple merge

diff --cc arch/arm/mm/dma-mapping.c
Simple merge

diff --cc arch/arm64/include/asm/dma-mapping.h
Simple merge

diff --cc arch/h8300/include/asm/dma-mapping.h
Simple merge

diff --cc arch/hexagon/include/asm/dma-mapping.h
Simple merge

diff --cc arch/ia64/include/asm/dma-mapping.h
Simple merge

diff --cc arch/microblaze/include/asm/dma-mapping.h
Simple merge

diff --cc arch/mips/cavium-octeon/dma-octeon.c
Simple merge

diff --cc arch/mips/include/asm/dma-mapping.h
Simple merge

diff --cc arch/mips/loongson64/common/dma-swiotlb.c
Simple merge

diff --cc arch/mips/mm/dma-default.c
Simple merge

diff --cc arch/mips/netlogic/common/nlm-dma.c
Simple merge

diff --cc arch/openrisc/include/asm/dma-mapping.h
Simple merge

diff --cc arch/powerpc/include/asm/dma-mapping.h
Simple merge

diff --cc arch/s390/include/asm/dma-mapping.h
Simple merge

diff --cc arch/sh/include/asm/dma-mapping.h
Simple merge

diff --cc arch/sparc/include/asm/dma-mapping.h
Simple merge

diff --cc arch/tile/include/asm/dma-mapping.h
Simple merge

diff --cc arch/unicore32/include/asm/dma-mapping.h
Simple merge

diff --cc arch/x86/include/asm/dma-mapping.h
Simple merge

diff --cc arch/x86/kernel/pci-dma.c
Simple merge

diff --cc arch/xtensa/include/asm/dma-mapping.h
Simple merge

diff --cc drivers/xen/swiotlb-xen.c
Simple merge

diff --cc include/asm-generic/dma-mapping-common.h
Simple merge