Hello Paul, thanks for the reply! On Thu, 2020-04-09 at 10:27 +1000, Paul Mackerras wrote: > On Wed, Apr 08, 2020 at 10:21:29PM +1000, Michael Ellerman wrote: > > We should be able to just allocate the rtas_args on the stack, it's only > > ~80 odd bytes. And then we can use rtas_call_unlocked() which doesn't > > take the global lock. > > Do we instantiate a 64-bit RTAS these days, or is it still 32-bit?
According to LoPAR, we can use instantiate-rtas or instantiate-rtas-64. It looks like we do instantiate-rtas today (grep pointed only to prom_instantiate_rtas()). > In the old days we had to make sure the RTAS argument buffer was > below the 4GB point. If that's still necessary then perhaps putting > rtas_args inside the PACA would be the way to go. Yes, we still need to make sure of this. I will study more about PACA and try to implement that way. Best regards, Leonardo Bras
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