Re: [PATCH for-next 2/4] RDMA/hns: Add IOMMU enable support in hip08

Christoph Hellwig
2017-11-07T15:58:05Z

On Tue, Nov 07, 2017 at 08:48:38AM -0700, Jason Gunthorpe wrote:
> Can't you just use vmalloc and dma_map that? Other drivers follow that
> approach..

You can't easily due to the flushing requirements. We used to do that
in XFS and it led to problems. You need the page allocator + vmap +
invalidate_kernel_vmap_range + flush_kernel_vmap_range to get the
cache flushing right.
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