Hi guys, On 05/07/18 10:50, Rafael J. Wysocki wrote: > On Tuesday, June 26, 2018 7:00:56 PM CEST James Morse wrote: >> The aim of this series is to wire arm64's SDEI into APEI. >> >> On arm64 we have three APEI notifications that are NMI-like, and >> in the unlikely event that all three are supported by a platform, >> they can interrupt each other. >> The GHES driver shouldn't have to deal with this, so this series aims >> to make it re-entrant. >> >> To do that, we refactor the estatus queue to allow multiple notifications >> to use it, then convert NOTIFY_SEA to always be described as NMI-like, >> and to use the estatus queue. >> >> From here we push the locking and fixmap choices out to the notification >> functions, and remove the use of per-ghes estatus and flags. This removes >> the in_nmi() 'timebomb' in ghes_copy_tofrom_phys(). >> >> Things get sticky when an NMI notification needs to know how big the >> CPER records might be, before reading it. This series splits >> ghes_estatus_read() to let us peek at the buffer. A side effect of this >> is the 20byte header will get read twice. (how does it work today? it >> reads the records into a per-ghes worst-case sized buffer, allocates >> the correct size and copies the records. in_nmi() use of this per-ghes >> buffer needs eliminating). >> >> One alternative was to trust firmware's 'max raw data length' and use >> that to allocate 'enough' memory. We don't use this value today, so its >> probably wrong on some sytem somewhere. >> >> Since v4 patches 5,8-15 are new, otherwise changes are noted in the patch. > Tony, I need your help with reviewing the APEI-related material here. > Can you please have a look at this series and let me know if there are > any concerns regarding it? Thanks. I think the only context from earlier versions is where Borislav spotted some issues with the ghes_proc() call at probe time and NMI-like notifications. >From https://www.spinics.net/lists/arm-kernel/msg653332.html : | Which means, that this code is not really reentrant and if should be | fixed to be callable from different contexts, then it should use private | buffers and be careful about locking. ... the patches for which have bloated this series. Thanks, James
