[PATCH v2 0/5] Cavium ThunderX uncore PMU support
jan.glauber at caviumnetworks.com
Wed Apr 27 03:51:56 PDT 2016
On Tue, Apr 26, 2016 at 02:53:54PM +0100, Will Deacon wrote:
> > That sounds like a good compromise.
> > So I could do the following:
> > 1) In the uncore setup check for CONFIG_NUMA, if set use the NUMA
> > information to determine the device node
> > 2) If CONFIG_NUMA is not set we check if we run on a socketed system
> > a) In that case we return an error and give a message that CONFIG_NUMA needs
> > to be enabled
> > b) Otherwise we have a single node system and use node_id = 0
> That sounds sensible to me. How do you "check if we run on a socketed
> system"? My assumption would be that you could figure this out from the
> firmware tables?
There are probably multiple ways to detect a socketed system, with some quite
hardware specific. I would like to avoid parsing DT (and ACPI) though,
A generic approach would be to do a query of the multiprocessor affinity
register (MPIDR_EL1) on all CPUs. The AFF2 part (bits 23:16) contains the
socket number on ThunderX. If this is non-zero on any CPU I would assume a
Would that be feasible?
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