lib/crypto: poly1305: Consolidate into single module

Consolidate the Poly1305 code into a single module, similar to various
other algorithms (SHA-1, SHA-256, SHA-512, etc.):

- Each arch now provides a header file lib/crypto/$(SRCARCH)/poly1305.h,
  replacing lib/crypto/$(SRCARCH)/poly1305*.c.  The header defines
  poly1305_block_init(), poly1305_blocks(), poly1305_emit(), and
  optionally poly1305_mod_init_arch().  It is included by
  lib/crypto/poly1305.c, and thus the code gets built into the single
  libpoly1305 module, with improved inlining in some cases.

- Whether arch-optimized Poly1305 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.  (The PPC64 one
  remains unconditionally disabled due to 'depends on BROKEN'.)

- Any additional arch-specific translation units for the optimized
  Poly1305 code, such as assembly files, are now compiled by
  lib/crypto/Makefile instead of lib/crypto/$(SRCARCH)/Makefile.

A special consideration is needed because the Adiantum code uses the
poly1305_core_*() functions directly.  For now, just carry forward that
approach.  This means retaining the CRYPTO_LIB_POLY1305_GENERIC kconfig
symbol, and keeping the poly1305_core_*() functions in separate
translation units.  So it's not quite as streamlined I've done with the
other hash functions, but we still get a single libpoly1305 module.

Note: to see the diff from the arm, arm64, and x86 .c files to the new
.h files, view this commit with 'git show -M10'.

Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20250829152513.92459-3-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@kernel.org>

1 files changed, 7 insertions, 9 deletions

diff --git a/include/crypto/internal/poly1305.h b/include/crypto/internal/poly1305.h
index c60315f47562..a72fff409ab8 100644
--- a/include/crypto/internal/poly1305.h
+++ b/include/crypto/internal/poly1305.h
@@ -30,12 +30,13 @@ void poly1305_core_blocks(struct poly1305_state *state,
 void poly1305_core_emit(const struct poly1305_state *state, const u32 nonce[4],
 			void *dst);
 
-void poly1305_block_init_arch(struct poly1305_block_state *state,
-			      const u8 raw_key[POLY1305_BLOCK_SIZE]);
-void poly1305_block_init_generic(struct poly1305_block_state *state,
-				 const u8 raw_key[POLY1305_BLOCK_SIZE]);
-void poly1305_blocks_arch(struct poly1305_block_state *state, const u8 *src,
-			  unsigned int len, u32 padbit);
+static inline void
+poly1305_block_init_generic(struct poly1305_block_state *desc,
+			    const u8 raw_key[POLY1305_BLOCK_SIZE])
+{
+	poly1305_core_init(&desc->h);
+	poly1305_core_setkey(&desc->core_r, raw_key);
+}
 
 static inline void poly1305_blocks_generic(struct poly1305_block_state *state,
 					   const u8 *src, unsigned int len,
@@ -45,9 +46,6 @@ static inline void poly1305_blocks_generic(struct poly1305_block_state *state,
 			     len / POLY1305_BLOCK_SIZE, padbit);
 }
 
-void poly1305_emit_arch(const struct poly1305_state *state,
-			u8 digest[POLY1305_DIGEST_SIZE], const u32 nonce[4]);
-
 static inline void poly1305_emit_generic(const struct poly1305_state *state,
 					 u8 digest[POLY1305_DIGEST_SIZE],
 					 const u32 nonce[4])