Re: [RFC] RNG rewrite...

[Deepak Saxena <dsaxena@plexity.net>]

On Oct 17 2005, at 19:31, Jeff Garzik was caught saying:
> >PCI devices, but I don't know enough about x86 to say whether msr 
> >instructions can execute out of userspace (or if we want them to...).
> 
> All of the hot path RNG stuff can and should be moved to userspace.
> 
> Right now the path is
> 
> 	kernel /dev/hwrandom -> rngd -> add /dev/random entropy
> 
> All three current vendors shown in hw_random.c are doable in userspace. 
>  Intel uses MMIO, AMD uses PIO, and VIA uses a specialized CPU 
> instruction.  As HPA mentioned, you can use the MSR driver for control.
> 
> Patches welcome!  http://sf.net/projects/gkernel/

OK...I already did most of a rewrite keeping the driver in user space
and added support for IXP4xx and OMAP but will look at the msr driver. 
However, looking at the MPC85xx and the Alchemy MIPs parts with RNGs, 
they have interrupt sources for error conditions so those need to be 
in kernel...

~Deepak

-- 
Deepak Saxena - dsaxena@plexity.net - http://www.plexity.net

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