When we compare the devices DMA mask to the amount of memory we need to
make sure we treat the DMA mask as an address boundary.  For example if
the DMA_MASK(32) and we have 4G of memory we'd incorrectly set the dma
ops to swiotlb.  We need to add one to the dma mask when we convert it.
Signed-off-by: NKumar Gala <galak@kernel.crashing.org>

We can kill unused swiotlb variable.
Signed-off-by: NFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Signed-off-by: NFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

This converts uses dma_map_ops struct (in include/linux/dma-mapping.h)
instead of POWERPC homegrown dma_mapping_ops.
Signed-off-by: NFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: NBecky Bruce <beckyb@kernel.crashing.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Now swiotlb_pci_dma_ops is identical to swiotlb_dma_ops; we can use
swiotlb_dma_ops with any devices. This removes swiotlb_pci_dma_ops.
Signed-off-by: NFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: NBecky Bruce <beckyb@kernel.crashing.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

This patch adds max_direct_dma_addr to struct dev_archdata to remove
addr_needs_map in struct dma_mapping_ops. It also converts
dma_capable() to use max_direct_dma_addr.

max_direct_dma_addr is initialized in pci_dma_dev_setup_swiotlb(),
called via ppc_md.pci_dma_dev_setup hook.

For further information:
http://marc.info/?t=124719060200001&r=1&w=2Signed-off-by: NFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: NBecky Bruce <beckyb@kernel.crashing.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

phys_to_dma() and dma_to_phys() are used instead of
swiotlb_phys_to_bus() and swiotlb_bus_to_phys().
Signed-off-by: NFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: NBecky Bruce <beckyb@kernel.crashing.org>

swiotlb doesn't use swiotlb_arch_address_needs_mapping(); it uses
dma_capalbe(). We can remove unnecessary
swiotlb_arch_address_needs_mapping().

We can remove swiotlb_addr_needs_map() and is_buffer_dma_capable() in
swiotlb_pci_addr_needs_map() too; dma_capable() handles the features
that both provide.
Signed-off-by: NFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: NBecky Bruce <beckyb@kernel.crashing.org>

swiotlb_bus_to_virt is unncessary; we can use swiotlb_bus_to_phys and
phys_to_virt instead.
Signed-off-by: NFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: NBecky Bruce <beckyb@kernel.crashing.org>

This patch includes the basic infrastructure to use swiotlb
bounce buffering on 32-bit powerpc.  It is not yet enabled on
any platforms.  Probably the most interesting bit is the
addition of addr_needs_map to dma_ops - we need this as
a dma_op because the decision of whether or not an addr
can be mapped by a device is device-specific.
Signed-off-by: NBecky Bruce <beckyb@kernel.crashing.org>
Acked-by: NKumar Gala <galak@kernel.crashing.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>