On 19/09/2018 16:33, Peter Maydell wrote: > On 19 September 2018 at 07:47, Roman Kapl <roman.k...@sysgo.com> wrote: >> It seems that the `dcbz` instruction is not emulated correctly (which may >> lead to some garbage in inittab?). However, if I manualy inline the >> `helper_dcbz_common` code into `helper dcbz`, it starts to work. > > This is because helper_dcbz_common() uses GETPC() to get the > return address inside generated code which will be used when > an exception occurs. This only works from a function called > directly from generated code. If you want to abstract out > into a second function, then you need: > * the second function to take a retaddr argument, which it > can then pass to cpu_stq_data_ra() > * the top level helpers called from TCG to pass GETPC() as > that retaddr parameter > > Incidentally, calling your secondary helper function > "helper_dcbz_common" is not ideal -- the "helper_" prefix > is generally used to indicate functions which are directly > called from TCG generated code as helper functions (which > does matter for some purposes, like this one).
Brilliant! I had no idea about the restrictions on GETPC(). Thanks so much for helping here, Peter. ATB, Mark.
