On Tue Jun 6, 2023 at 11:59 PM AEST, Cédric Le Goater wrote: > On 6/4/23 01:36, Nicholas Piggin wrote: > > This adds support for chiptod and core timebase state machine models in > > the powernv POWER9 and POWER10 models. > > > > This does not actually change the time or the value in TB registers > > (because they are alrady synced in QEMU), but it does go through the > > motions. It is enough to be able to run skiboot's chiptod initialisation > > code that synchronises core timebases (after a patch to prevent skiboot > > skipping chiptod for QEMU, posted to skiboot mailing list). > > > > Sorry there was some delay since the last posting. There is a bit more > > interest in this recently but feedback and comments from RFC was not > > forgotten and is much appreciated. > > > > https://lists.gnu.org/archive/html/qemu-ppc/2022-08/msg00324.html > > > > I think I accounted for everything except moving register defines to the > > .h file. I'm on the fence about that but if they are only used in the .c > > file I think it's okay to keep them there for now. I cut out a lot of > > unused ones so it's not so cluttered now. > > > > Lots of other changes and fixes since that RFC. Notably: > > - Register names changed to match the workbook names instead of skiboot. > > - TFMR moved to timebase_helper.c from misc_helper.c > > - More comprehensive model and error checking, particularly of TFMR. > > - POWER10 with multi-chip support. > > - chiptod and core timebase linked via specific state instead of TFMR. > > > The chiptod units are not exposed to the OS, it is all handled at FW > level AFAIK. Could the OPAL people provide some feedback on the low level > models ?
Well, no takers so far. I guess I'm a OPAL people :) I did some of the P10 chiptod addressing in skiboot, at least. This patch does work with the skiboot chiptod driver at least. I would eventually like to add in the ability to actually change the TB with it, and inject errors and generate HMIs because that's an area that seem to be a bit lacking (most of such testing seemed to be done on real hardware using special time facility corruption injection). But yes for now it is a bit difficult to verify it does much useful aside from booting skiboot (+ patch to enable chiptod on QEMU I posted recently). Thanks, Nick
