[ofa-general] [PATCH RFC] RDMA/cxgb3: Fixes for zero-stag.
swise at opengridcomputing.com
Sun Jun 29 09:04:29 PDT 2008
Or Gerlitz wrote:
> Steve Wise wrote:
>> Note: we need to place a few restrictions on zero-stag usage:
> Hi Steve,
> Can you spare few words on zero-stags? is it the chelsio way to
> implement dma_mr - that is an stag that tells the HW "don't do any
> address translation as the VA in the work-request is dma address", etc.
Sort of. It is not exactly a dma_mr. dma_mrs allow remote IO. The
zero-stag is an iWARP verbs concept. zero-stag can be used by kernel
users as the lkey in any SGE that requires only local access rights. If
the lkey is zero, then the rnic interprets the addr field in the SGE as
a bus address.
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