How alloc non-cache type memory?

TAMURA Kent kent at
Thu Aug 4 09:02:04 GMT 2005

> > > > Is there any way to allocate Non-Cached type physical memory for dma
> > > > transfer in FreeBSD?
> > > BUS_DMA_NOCACHE flag for bus_dmamem_alloc(9) may perform it
> > > though FreeBSD/i386 does not support it.

> I'm sorry. I found BUS_DMA_NOCACHE flag in src/sys/sys/bus_dma.h,
> But it not implement in i386. It only used in sparc64/iommu.c

Right.  So you need to implement it in sys/i386/i386/busdma_machdep.c,
or call pmap functions directly in your driver.

TAMURA Kent <kent_2005 at> <kent at>

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