Signed-off-by: Michael Opdenacker <michael@free-electrons.com>
Signed-off-by: Adrian Bunk <bunk@stusta.de>

We don't currently support the noncoherent DMA API, but it needs to
be provided for kernels with devres to link.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

The DMA cache handling functions take virtual addresses, but in the
form of unsigned long arguments.  This leads to a little confusion
about what exactly they take.  So, convert them to take const void *
instead.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

dma_is_consistent() is ill-designed in that it does not have a struct
device pointer argument which makes proper support for systems that consist
of a mix of coherent and non-coherent DMA devices hard.  Change
dma_is_consistent to take a struct device pointer as first argument and fix
the sole caller to pass it.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Cc: James Bottomley <James.Bottomley@steeleye.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

/*
 * Note: Drivers should NOT use this function directly, as it will break
 * platforms with CONFIG_DMABOUNCE.
 * Use the driver DMA support - see dma-mapping.h (dma_sync_*)
 */

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Signed-off-by: David Woodhouse <dwmw2@infradead.org>

Patch from Lennert Buytenhek

This patch adds support for the I/O coherent cache available on the
xsc3.  The approach is to provide a simple API to determine whether the
chipset supports coherency by calling arch_is_coherent() and then
setting the appropriate system memory PTE and PMD bits.  In addition,
we call this API on dma_alloc_coherent() and dma_map_single() calls.
A generic version exists that will compile out all the coherency-related
code that is not needed on the majority of ARM systems.

Note that we do not check for coherency in the dma_alloc_writecombine()
function as that still requires a special PTE setting.  We also don't
touch dma_mmap_coherent() as that is a special ARM-only API that is by
definition only used on non-coherent system.

Signed-off-by: Deepak Saxena <dsaxena@plexity.net>
Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

)


From: Russell King <rmk+lkml@arm.linux.org.uk>

The ARM dma_supported() is rather basic, and I don't think it takes into
account everything that it should do (eg, whether the mask agrees with what
we'd return for GFP_DMA allocations).  Note this.

Signed-off-by: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>