Subject: Re: bzero
To: Martin J. Laubach <>
From: David Edelsohn <>
List: port-powerpc
Date: 11/03/2001 22:46:06
	PowerPC cache line size is not always 32 bytes.  On OpenFirmware
systems, the value is provided in the device-tree.  I think all 32-bit 6xx
and 7xx chips have used 32 bytes so far.  This is incorrect for embedded
(4xx, 5xx, 8xx) chips which have a cache line size of 16, I believe, and
64-bit chips with a cache line of 128 bytes.  Future chips may not use the
same values.

	PowerPC Linux is looking at passing the value in an aux entry on
program startup.  The problem is what to do with the information because 
looking up the value may eat the entire performance advantage.