Re: Probing for native availability of isel from userspace
From: malc <hidden>
Date: 2012-09-22 20:17:38
On Sun, 23 Sep 2012, Benjamin Herrenschmidt wrote:
On Sat, 2012-09-22 at 21:08 +0200, Segher Boessenkool wrote:quoted
quoted
Thanks for suggestion, but i'd rather not play with heuristics.Have a look at /sys/kernel/debug/powerpc/emulated_instructions/ then?Userspace should *NEVER* rely on the content of debugfs, it will change with time, it is not a guaranteed ABI, it's purely for people to look at... for debugging.
Furthermore this box simply doesn't have it built-in...
Unfortunately we don't expose ISEL support via features (maybe we should, this is reasonably easy to fix, except that we are running short on feature bits and adding a new set of bits isn't totally trivial). At this stage I would recommend using arch 2.06 as your key/trigger and either add a handful of known PVR values (mfpvr is emulated) for other CPUs you know support it (there shouldn't be that many), or just do the heuristic :-(
Thank you. -- mailto:av1474@comtv.ru