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>

3 files changed, 9 insertions, 36 deletions

diff --git a/lib/crypto/powerpc/Kconfig b/lib/crypto/powerpc/Kconfig
index 2eaeb7665a6a..e41012a61876 100644
--- a/lib/crypto/powerpc/Kconfig
+++ b/lib/crypto/powerpc/Kconfig
@@ -6,11 +6,3 @@ config CRYPTO_CHACHA20_P10
 	default CRYPTO_LIB_CHACHA
 	select CRYPTO_LIB_CHACHA_GENERIC
 	select CRYPTO_ARCH_HAVE_LIB_CHACHA
-
-config CRYPTO_POLY1305_P10
-	tristate
-	depends on PPC64 && CPU_LITTLE_ENDIAN && VSX
-	depends on BROKEN # Needs to be fixed to work in softirq context
-	default CRYPTO_LIB_POLY1305
-	select CRYPTO_ARCH_HAVE_LIB_POLY1305
-	select CRYPTO_LIB_POLY1305_GENERIC
diff --git a/lib/crypto/powerpc/Makefile b/lib/crypto/powerpc/Makefile
index 5709ae14258a..778a04edd226 100644
--- a/lib/crypto/powerpc/Makefile
+++ b/lib/crypto/powerpc/Makefile
@@ -2,6 +2,3 @@
 
 obj-$(CONFIG_CRYPTO_CHACHA20_P10) += chacha-p10-crypto.o
 chacha-p10-crypto-y := chacha-p10-glue.o chacha-p10le-8x.o
-
-obj-$(CONFIG_CRYPTO_POLY1305_P10) += poly1305-p10-crypto.o
-poly1305-p10-crypto-y := poly1305-p10-glue.o poly1305-p10le_64.o
diff --git a/lib/crypto/powerpc/poly1305-p10-glue.c b/lib/crypto/powerpc/poly1305.h
index 184a71f9c1de..b8ed098a0e95 100644
--- a/lib/crypto/powerpc/poly1305-p10-glue.c
+++ b/lib/crypto/powerpc/poly1305.h
@@ -1,15 +1,13 @@
-// SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * Poly1305 authenticator algorithm, RFC7539.
  *
  * Copyright 2023- IBM Corp. All rights reserved.
  */
 #include <asm/switch_to.h>
-#include <crypto/internal/poly1305.h>
 #include <linux/cpufeature.h>
 #include <linux/jump_label.h>
 #include <linux/kernel.h>
-#include <linux/module.h>
 #include <linux/unaligned.h>
 
 asmlinkage void poly1305_p10le_4blocks(struct poly1305_block_state *state, const u8 *m, u32 mlen);
@@ -30,8 +28,8 @@ static void vsx_end(void)
 	preempt_enable();
 }
 
-void poly1305_block_init_arch(struct poly1305_block_state *dctx,
-			      const u8 raw_key[POLY1305_BLOCK_SIZE])
+static void poly1305_block_init(struct poly1305_block_state *dctx,
+				const u8 raw_key[POLY1305_BLOCK_SIZE])
 {
 	if (!static_key_enabled(&have_p10))
 		return poly1305_block_init_generic(dctx, raw_key);
@@ -40,10 +38,9 @@ void poly1305_block_init_arch(struct poly1305_block_state *dctx,
 	dctx->core_r.key.r64[0] = get_unaligned_le64(raw_key + 0);
 	dctx->core_r.key.r64[1] = get_unaligned_le64(raw_key + 8);
 }
-EXPORT_SYMBOL_GPL(poly1305_block_init_arch);
 
-void poly1305_blocks_arch(struct poly1305_block_state *state, const u8 *src,
-			  unsigned int len, u32 padbit)
+static void poly1305_blocks(struct poly1305_block_state *state, const u8 *src,
+			    unsigned int len, u32 padbit)
 {
 	if (!static_key_enabled(&have_p10))
 		return poly1305_blocks_generic(state, src, len, padbit);
@@ -60,31 +57,18 @@ void poly1305_blocks_arch(struct poly1305_block_state *state, const u8 *src,
 	}
 	vsx_end();
 }
-EXPORT_SYMBOL_GPL(poly1305_blocks_arch);
 
-void poly1305_emit_arch(const struct poly1305_state *state,
-			u8 digest[POLY1305_DIGEST_SIZE],
-			const u32 nonce[4])
+static void poly1305_emit(const struct poly1305_state *state,
+			  u8 digest[POLY1305_DIGEST_SIZE], const u32 nonce[4])
 {
 	if (!static_key_enabled(&have_p10))
 		return poly1305_emit_generic(state, digest, nonce);
 	poly1305_emit_64(state, nonce, digest);
 }
-EXPORT_SYMBOL_GPL(poly1305_emit_arch);
 
-static int __init poly1305_p10_init(void)
+#define poly1305_mod_init_arch poly1305_mod_init_arch
+static void poly1305_mod_init_arch(void)
 {
 	if (cpu_has_feature(CPU_FTR_ARCH_31))
 		static_branch_enable(&have_p10);
-	return 0;
 }
-subsys_initcall(poly1305_p10_init);
-
-static void __exit poly1305_p10_exit(void)
-{
-}
-module_exit(poly1305_p10_exit);
-
-MODULE_LICENSE("GPL");
-MODULE_AUTHOR("Danny Tsen <dtsen@linux.ibm.com>");
-MODULE_DESCRIPTION("Optimized Poly1305 for P10");