On Fri, May 17, 2024 at 04:52:47PM +0200, Clément Léger wrote:
Since a few extensions (Zicbom/Zicboz) already needs validation and future ones will need it as well (Zc*) add a validate() callback to struct riscv_isa_ext_data. This require to rework the way extensions are parsed and split it in two phases. First phase is isa string or isa extension list parsing and consists in enabling all the extensions in a temporary bitmask (source isa) without any validation. The second step "resolves" the final isa bitmap, handling potential missing dependencies. The mechanism is quite simple and simply validate each extension described in the source bitmap before enabling it in the resolved isa bitmap. validate() callbacks can return either 0 for success, -EPROBEDEFER if extension needs to be validated again at next loop. A previous ISA bitmap is kept to avoid looping multiple times if an extension dependencies are never satisfied until we reach a stable state. In order to avoid any potential infinite looping, allow looping a maximum of the number of extension we handle. Zicboz and Zicbom extensions are modified to use this validation mechanism.
I wish we weren't doin' it at all, but since we have to, I think what you've got here is good. Reviewed-by: Conor Dooley conor.dooley@microchip.com
Do you want me to send some patches for the F/V stuff we discussed previously?
Cheers, Conor.