Re: [PATCH -mm 0/11] fix iommu sg merging problem

Jens Axboe
2007-10-24T13:24:50Z

On Wed, Oct 24 2007, FUJITA Tomonori wrote:
> IOMMUs merges scatter/gather segments without considering a low level
> driver's restrictions. The problem is that IOMMUs can't access to the
> limitations because they are in request_queue.
>
> This patchset introduces a new structure, device_dma_parameters,
> including dma information. A pointer to device_dma_parameters is added
> to struct device. The bus specific structures (like pci_dev) includes
> device_dma_parameters. Low level drivers can use dma_set_max_seg_size
> to tell IOMMUs about the restrictions.
>
> We can move more dma stuff in struct device (like dma_mask) to struct
> device_dma_parameters later (needs some cleanups before that).
>
> This includes patches for all the IOMMUs that could merge sg (x86_64,
> ppc, IA64, alpha, sparc64, and parisc) though only the ppc patch was
> tested. The patches for other IOMMUs are only compile tested.
>
> Thanks to everyone for the comments on the previous submission
> to linux-scsi.
>
> This is against 2.6.24-rc1. The same patchset is also available:

Looks good to me, I think we should get this included sooner rather than
later.

--
Jens Axboe