Messages in this thread | | | From | akepner@sgi ... | Date | Mon, 27 Aug 2007 15:20:27 -0700 | Subject | Re: [PATCH 0/3] pci: let devices flush DMA to host memory |
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On Mon, Aug 27, 2007 at 04:05:48PM -0600, Grant Grundler wrote:
> ..... > After reading the thread, my take is we need a more elegant way for a > device driver to handle registration of DMA regions allocated by user > space. The API would "make this page/region act like dma_alloc_coherent()". > That implies strong ordering between CPU and DMA to/from the device. > Maybe the code is the right thing and I want a name that makes > sense in the context of current DMA API.
Need to think about this...
> > On IRC, willy suggested an mmap() flag and that sounds reasonable too > though I don't know if it's feasible. >
Yeah, we're doing something like this now as a band-aid solution. Not a flag to mmap(), but a magic offset value. But it wasn't acceptable to the maintainer of the mthca IB driver (Roland Dreier), hence the new proposal....
-- Arthur
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