Re: [PATCH -mm 01/11] add device_dma_parameters structure

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FUJITA Tomonori wrote:
iommu code merges scatter/gather segments without considering a low
level driver's restrictions. The problem is that iommu code can't
access to the limitations because they are in request_queue.

This patch adds a new structure, device_dma_parameters, including dma
information. A pointer to device_dma_parameters is added to struct
device.

- there are only max_segment_size and segment_boundary_mask there but
we'll move more dma stuff in struct device (like dma_mask) to struct
device_dma_parameters later. segment_boundary_mask is not supported
yet.

- new accessors for the dma parameters are added. So we can easily
change where to place struct device_dma_parameters in the future.

- dma_get_max_seg_size returns 64K if dma_parms in struct device isn't
set up properly. 64K is the default max_segment_size in the block
layer.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@xxxxxxxxxxxxx>
---
 include/linux/device.h      |   11 +++++++++++
 include/linux/dma-mapping.h |   15 +++++++++++++++
 2 files changed, 26 insertions(+), 0 deletions(-)

ACK


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