Hi, We'd like to be able to pass algorithm-specific parameters to comp backends. As of this moment, crypto usees hard-coded default values and does not permit any run-time algorithm configuration, which in some cases simply disables the most interesting functionality. E.g. zstd can be configured to use a pre-trained (in the user-space) compression dictionary, which significantly changes algorithms characteristics. Another, obvious and trivial example, is algorithms compression level. The problem is that we need to pass params to cra_init() function, because for some algorithms that's the only place where configuration can take place (e.g. zstd). Changing cra_init() to accept additional `struct crypto_comp_params` looks to be a little intrusive so before I write any patches I'd like to hear your thoughts.
