On Wed, 06 Jan 1999 18:41:03 +0530 
 Esha <esha@sharada.ncore.soft.net> wrote:

 > Hi,
 > 
 > If  the bus_dmamap_load_uio() is not there in 1.3.3 then is the
 > following way correct ?
 > 
 > call bus_dmamem_alloc()
 > 
 > call bus_dmamem_map()
 > 
 > pass the dma-safe address to the user through mmap entry point.
 > 
 > 
 > Is the above idea correct ?

That is certainly one way you could do it, yes.  Note, memory mapped into
DMA space with bus_dmamap_load_uio() is not necessarily DMA-safe; it's
whatever random memory the application happened to have.  So, the operations
are not really equivalent, but the latter will work fine, but may just be
less convenient for you.

(DMA-mapping non-DMA-safe memory happens all the time, BTW; it just may need
special handling by the bus_dma backends...)

Jason R. Thorpe                                       thorpej@nas.nasa.gov
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