[PATCH 0/4] allow drivers to flush in-flight DMA

From: akepner
Date: Tue Sep 25 2007 - 19:59:55 EST

This is a followup to http://lkml.org/lkml/2007/8/24/280

Despite Grant's desire for a more elegant solution, there's
not much new here. I moved the API change from pci.h to
dma-mapping.h and removed the pci_ prefix from the name.

Problem Description
On Altix, DMA may be reordered within the NUMA interconnect.
This can be a problem with Infiniband, where DMA to Completion Queues
allocated in user-space can race with data DMA. This patchset allows
a driver to associate a user-space memory region with a "dmaflush"
attribute, so that writes to the memory region flush in-flight DMA,
preventing the CQ/data race.

There are four patches in this set:

[1/4] dma: add dma_flags_set_dmaflush() to dma interface
[2/4] dma: redefine dma_flags_set_dmaflush() for sn-ia64
[3/4] dma: document dma_flags_set_dmaflush()
[4/4] mthca: allow setting "dmaflush" attribute on user-allocated memory

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