Aligned malloc for dma and mbufs for powerpc ppc405gp (was dma-vm-cache)

Smith, Gene gene.smith at siemens.com
Thu Nov 11 14:23:14 UTC 2004


Feng, Shuchen wrote, On 11/10/2004 11:51 PM:
> 
> How about the dma-vme-cache issue ?
> Did the hardware/firmware take care of the cache snoop ?
> Did you have to write the software snoop as what Joel suggested earlier ?
> If so, is it shareable ?
> 
>> Joel Sherrill wrote :
>> bus_dmamap_create();
>> bus_dmamem_alloc();
>> bus_dmamap_load();
>> bus_dmamap_sync();
>>THen it would be the BSPs responsibility to provide the implementation
>>of these routines with some shared code having default no-op versions.
>

Some of these calls got deep into BSD Virtual Memory calls which don't 
map to rtems. So I greatly simplified most of them. Only bus_dmamap_sync 
I pretty much left alone since it is called a lot during runtime.

Right now I have just moved the routines into my network.c so they are 
not "sharable" between BSPs right now. If you mean is the code itself 
sharable then I can email it to you if you would like to see it.
It is based on BSD routine:
\netbsd-src\sys\arch\powerpc\ibm4xx\dev\if_emac.c

-gene








> 
> 
> Thanks,
> Kate
> 



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