Subject: Re: 2.5 or 2.4 kernel profiling

From: Dan Malek <[email-masked]>
Date: Tue, 12 Dec 2000 16:03:19 -0500

Brian Ford wrote:

> Does your statement mean that 60x bus memory is mapped
> _PAGE_COHERENT?  What is the exact meaning of the GBL bit in the FCRx
> register?

The GBL flag in the FCRx is orthogonal to the PAGE_COHERENT (M in WIMG)
of the processor.  Since the CPM is a bus master, the GBL flag is used
to indicate whether it should announce memory updates in the cache
protocol.  The CPM shared memory is mapped uncached to the processor,
and I don't see any reason to do that differently.  For some reason,
I believe the GBL flag also ensures the CPM DMA will snoop the processor
cache, and setting PAGE_COHERENT isn't necessary.  I don't know why
I think this, except it appears to work that way :-).  Logically, we
should be required to set PAGE_COHERENT......It's a note on my board,
I'll keep looking at it.

Thanks.

	-- Dan

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