On some MIPS systems, a subset of devices may have DMA coherent with CPU
caches. For example in systems including a MIPS I/O Coherence Unit
(IOCU), some devices may be connected to that IOCU whilst others are
not.

Prior to this patch, we have a plat_device_is_coherent() function but no
implementation which does anything besides return a global true or
false, optionally chosen at runtime. For devices such as those described
above this is insufficient.

Fix this by tracking DMA coherence on a per-device basis with a
dma_coherent field in struct dev_archdata. Setting this from
arch_setup_dma_ops() takes care of devices which set the dma-coherent
property via device tree, and any PCI devices beneath a bridge described
in DT, automatically.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14349/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Use asm-generic/dma-mapping-common.h to handle all DMA mapping operations
and establish a default get_dma_ops() that forwards all operations to the
existing code.

Augment dev_archdata to carry a pointer to the struct dma_map_ops, allowing
DMA operations to be overridden on a per device basis.  Currently this is
never filled in, so the default dma_map_ops are used.  A follow-on patch
sets this for Octeon PCI devices.

Also initialize the dma_debug system as it is now used if it is configured.

Includes fixes by Kevin Cernekee <cernekee@gmail.com>.
Signed-off-by: NDavid Daney <ddaney@caviumnetworks.com>
Patchwork: http://patchwork.linux-mips.org/patch/1637/
Patchwork: http://patchwork.linux-mips.org/patch/1678/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Recent git versions now warn about those and they've always been a bit of
an annoyance.
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Add arch specific dev_archdata to struct device

Adds an arch specific struct dev_arch to struct device. This enables
architecture to add specific fields to every device in the system, like
DMA operation pointers, NUMA node ID, firmware specific data, etc...
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: NAndi Kleen <ak@suse.de>
Acked-By: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>