[PATCH 4/6] arm64: topology: add MPIDR-based detection

Mark Brown broonie at kernel.org
Mon May 19 05:14:33 PDT 2014

On Mon, May 19, 2014 at 10:57:40AM +0100, Sudeep Holla wrote:
> On 16/05/14 19:39, Mark Brown wrote:
> >On Fri, May 16, 2014 at 05:34:04PM +0100, Sudeep Holla wrote:

> >>Take a simple example of system with 2 Quad core clusters.
> >>The mpidr_hash.shift_aff[1] will be 6 as you need minimum 2 bits to represent
> >>aff[0]. So you will end up with second cluster with id = 4 instead of 1.

> >This isn't a problem, the clusters can have any numbers so long as they
> >are distinct.  There is no other requirement.

> IIUC these topology information is exposed via sysfs. So it's good to have
> uniformity though they can have any number. As mentioned in the example, if the
> linearisation depend on aff[0], then this factor will not be uniform.

So your concern is that the width of aff[0] will vary?  That's
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