On Tue, Mar 21, 2017 at 11:48:02AM +0800, Fu Wei wrote: > Hi Mark, Lurndal, > > >> The base server system implements _a_ Generic Watchdog as > >> specified in APPENDIX A: Generic Watchdog. > > > > It is a requirement of a conforming implementation that there > > be a generic watchdog (impl as per the appendix). That doesn't preclude > > an implmentation from providing additional watchdogs (for example, if > > the processor implements EL3, it is likely that an implementation > > will include a secure watchdog as well as a non-secure watchdog). > > > > The SBSA describes the minimal hardware requirements for a > > compliant server. > > So I think, for the SBSA watchdog: > > (1) there maybe more then one non-secure watchdog in GTDT I suppose a firmware vendor could chose to expose more than the platform minimum to linux. Not quite sure what linux would do with it :-) > > (2) we may also need to skip secure watchdogs in GTDT, > and only register non-secure watchdogs into platform resources. The secure watchdog will, be definition, never be accessible to non-secure EL2 or non-secure EL1, so only in the case of a secure EL1 operating system would the secure watchdog ever be conveyed through ACPI. I don't think secure EL1 is in the scope of the SBSA, or something that needs to be accomodated in the GTDT at this time. scott -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
