On Nov 29, 2023, at 04:12, Eric Biggers <ebiggers@xxxxxxxxxx> wrote: > On Tue, Nov 28, 2023 at 05:54:49PM +0000, Conor Dooley wrote: >>> +static inline bool check_aes_ext(void) >>> +{ >>> + return riscv_isa_extension_available(NULL, ZVKNED) && >>> + riscv_vector_vlen() >= 128; >>> +} >> >> I'm not keen on this construct, where you are checking vlen greater than >> 128 and the presence of Zvkned without checking for the presence of V >> itself. Can you use "has_vector()" in any places where you depend on the >> presence of vector please? > > Shouldn't both of those things imply vector support already? The vector crypto extensions imply `V` extension. Should we still need to check the `V` explicitly? https://github.com/riscv/riscv-crypto/blob/main/doc/vector/riscv-crypto-spec-vector.adoc#1-extensions-overview >> Also, there are potentially a lot of places in this drivers where you >> can replace "riscv_isa_extension_available()" with >> "riscv_has_extension_likely()". The latter is optimised with >> alternatives, so in places that are going to be evaluated frequently it >> may be beneficial for you. > > These extension checks are only executed in module_init functions, so they're > not performance critical. All `riscv_isa_extension_available()` calls in crypto drivers are called once in the module init calls. Should we still need that `riscv_has_extension_likely()` with a little more code size? > - Eric