On Mon, 2016-04-18 at 15:05 +0200, Christophe Lombard wrote: > In the POWERVM environement, the PHYP CoherentAccel component manages
PowerVM is correct I think. > the state of the Coherant Accelerator Processor Interface adapter and ^ (CAPI) > virtualizes CAPI resources, handles CAPP, PSL, PSL Slice errors - and > interrupts - and provides a new set of HCALLs for the OS APIs to utilize ^ hcall (as below?) > AFUs. AFUs ? (you define it below) > During the course of operation, a coherent platform function can > encounter errors. Some possible reason for errors are: > • Hardware recoverable and unrecoverable errors > • Transient and over-threshold correctable errors > > PHYP implements its own state model for the coherent platform function. > The current state of this Acclerator Fonction Unit (AFU) is available > through a hcall. > > In case of low-level troubles (or error injection), The PHYP component > may reset the card and change the AFU state. The PHYP interface doesn't > provide any way to be notified when that happens. Ugh. > The current implementation of the cxl driver, for the POWERVM > environment, follows the general error recovery procedures required to What are "the general error recovery procedures" ? > reset operation of the coherent platform function. The platform firmware > resets and reconfigures hardware when an external action is required - > attach/detach a process, link ok, .... Platform firmware does that at our request or by itself? > The purpose of this patch is to interact with the external driver What's an external driver? > (where the AFU is shown) even if no action is required. A kernel thread But no action is required, so why do we need to do anything? > is needed to check every x seconds the current state of the AFU to see > if we need to enter an error recovery path. I don't really understand what this is doing and why we want it. It sounds like we're waking the cpu up every 3 seconds and having it poll the hypervisor, for each AFU? As far as the implementation, I can't see any reason why you need your own kthreads, can't you just use queue_work() ? cheers _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev