Consolidate the ChaCha code into a single module (excluding
chacha-block-generic.c which remains always built-in for random.c),
similar to various other algorithms:
- Each arch now provides a header file lib/crypto/$(SRCARCH)/chacha.h,
replacing lib/crypto/$(SRCARCH)/chacha*.c. The header defines
chacha_crypt_arch() and hchacha_block_arch(). It is included by
lib/crypto/chacha.c, and thus the code gets built into the single
libchacha module, with improved inlining in some cases.
- Whether arch-optimized ChaCha is buildable is now controlled centrally
by lib/crypto/Kconfig instead of by lib/crypto/$(SRCARCH)/Kconfig.
The conditions for enabling it remain the same as before, and it
remains enabled by default.
- Any additional arch-specific translation units for the optimized
ChaCha code, such as assembly files, are now compiled by
lib/crypto/Makefile instead of lib/crypto/$(SRCARCH)/Makefile.
This removes the last use for the Makefile and Kconfig files in the
arm64, mips, powerpc, riscv, and s390 subdirectories of lib/crypto/. So
also remove those files and the references to them.
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20250827151131.27733-7-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
13cecc526d