Hi Fellows,
I want to switch stack pointer to SP0 from SP1 every time an exception is taken to EL1 on armv8. I execute MSR SPSel, #0 to do this. My question is that is it necessary to use an ISB intruction etc. after it? If yes, what are the performance overheads if any? The reference manual does say the following:
"Changing PSTATE.SPSel to use EL0 synchronizes any updates to SP_EL0 that have been written by an MSR to SP_EL0, without the need for additional synchronization."
But I am not sure it concerns my question. Thanks.
Best Regards,
Mughees