PCI caching question related to mvme5500

Chris Caudle chris at chriscaudle.org
Tue Nov 1 16:19:50 UTC 2005


On Tuesday 01 November 2005 05:06 am, Peter Dufault wrote:
> This has to do with accessing a PCI  
> card's memory through a cached region.

I don't think I've ever seen anyone map a PCI card into cacheable memory 
space.
How does the cache know whether the data in the cache is out of date or not?  
Since it is a data acquisition card, presumably data could have been acquired 
since the last time the cache was filled, so how do you mark the data 
currently in the cache as invalid?  Does the driver issue a cache flush 
command every time it begins to read in the new data?

-- 
Chris Caudle



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