lib/crypto: chacha: Consolidate into single module

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>

1 files changed, 4 insertions, 24 deletions

diff --git a/include/crypto/chacha.h b/include/crypto/chacha.h
index be25a0b65a05..38e26dff27b0 100644
--- a/include/crypto/chacha.h
+++ b/include/crypto/chacha.h
@@ -45,19 +45,11 @@ static inline void chacha20_block(struct chacha_state *state,
 	chacha_block_generic(state, out, 20);
 }
 
-void hchacha_block_arch(const struct chacha_state *state,
-			u32 out[HCHACHA_OUT_WORDS], int nrounds);
 void hchacha_block_generic(const struct chacha_state *state,
 			   u32 out[HCHACHA_OUT_WORDS], int nrounds);
 
-static inline void hchacha_block(const struct chacha_state *state,
-				 u32 out[HCHACHA_OUT_WORDS], int nrounds)
-{
-	if (IS_ENABLED(CONFIG_CRYPTO_ARCH_HAVE_LIB_CHACHA))
-		hchacha_block_arch(state, out, nrounds);
-	else
-		hchacha_block_generic(state, out, nrounds);
-}
+void hchacha_block(const struct chacha_state *state,
+		   u32 out[HCHACHA_OUT_WORDS], int nrounds);
 
 enum chacha_constants { /* expand 32-byte k */
 	CHACHA_CONSTANT_EXPA = 0x61707865U,
@@ -93,20 +85,8 @@ static inline void chacha_init(struct chacha_state *state,
 	state->x[15] = get_unaligned_le32(iv + 12);
 }
 
-void chacha_crypt_arch(struct chacha_state *state, u8 *dst, const u8 *src,
-		       unsigned int bytes, int nrounds);
-void chacha_crypt_generic(struct chacha_state *state, u8 *dst, const u8 *src,
-			  unsigned int bytes, int nrounds);
-
-static inline void chacha_crypt(struct chacha_state *state,
-				u8 *dst, const u8 *src,
-				unsigned int bytes, int nrounds)
-{
-	if (IS_ENABLED(CONFIG_CRYPTO_ARCH_HAVE_LIB_CHACHA))
-		chacha_crypt_arch(state, dst, src, bytes, nrounds);
-	else
-		chacha_crypt_generic(state, dst, src, bytes, nrounds);
-}
+void chacha_crypt(struct chacha_state *state, u8 *dst, const u8 *src,
+		  unsigned int bytes, int nrounds);
 
 static inline void chacha20_crypt(struct chacha_state *state,
 				  u8 *dst, const u8 *src, unsigned int bytes)