lib/crypto: blake2s: Drop excessive const & rename block => data

A couple more small cleanups to the BLAKE2s code before these things get
propagated into the BLAKE2b code:

- Drop 'const' from some non-pointer function parameters.  It was a bit
  excessive and not conventional.

- Rename 'block' argument of blake2s_compress*() to 'data'.  This is for
  consistency with the SHA-* code, and also to avoid the implication
  that it points to a singular "block".

No functional changes.

Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20251018043106.375964-4-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@kernel.org>

4 files changed, 18 insertions, 20 deletions

diff --git a/lib/crypto/arm/blake2s-core.S b/lib/crypto/arm/blake2s-core.S
index 78e758a7cb3e..14eb7c18a836 100644
--- a/lib/crypto/arm/blake2s-core.S
+++ b/lib/crypto/arm/blake2s-core.S
@@ -171,7 +171,7 @@
 
 //
 // void blake2s_compress(struct blake2s_ctx *ctx,
-//			 const u8 *block, size_t nblocks, u32 inc);
+//			 const u8 *data, size_t nblocks, u32 inc);
 //
 // Only the first three fields of struct blake2s_ctx are used:
 //	u32 h[8];	(inout)
@@ -184,7 +184,7 @@ ENTRY(blake2s_compress)
 
 .Lnext_block:
 	// r0 is 'ctx'
-	// r1 is 'block'
+	// r1 is 'data'
 	// r3 is 'inc'
 
 	// Load and increment the counter t[0..1].
@@ -275,7 +275,7 @@ ENTRY(blake2s_compress)
 	// Advance to the next block, if there is one.  Note that if there are
 	// multiple blocks, then 'inc' (the counter increment amount) must be
 	// 64.  So we can simply set it to 64 without re-loading it.
-	ldm		sp, {r0, r1, r2}	// load (ctx, block, nblocks)
+	ldm		sp, {r0, r1, r2}	// load (ctx, data, nblocks)
 	mov		r3, #64			// set 'inc'
 	subs		r2, r2, #1		// nblocks--
 	str		r2, [sp, #8]
diff --git a/lib/crypto/arm/blake2s.h b/lib/crypto/arm/blake2s.h
index ce009cd98de9..42c04440c191 100644
--- a/lib/crypto/arm/blake2s.h
+++ b/lib/crypto/arm/blake2s.h
@@ -2,4 +2,4 @@
 
 /* defined in blake2s-core.S */
 void blake2s_compress(struct blake2s_ctx *ctx,
-		      const u8 *block, size_t nblocks, u32 inc);
+		      const u8 *data, size_t nblocks, u32 inc);
diff --git a/lib/crypto/blake2s.c b/lib/crypto/blake2s.c
index 1ad36cb29835..6182c21ed943 100644
--- a/lib/crypto/blake2s.c
+++ b/lib/crypto/blake2s.c
@@ -29,16 +29,15 @@ static const u8 blake2s_sigma[10][16] = {
 	{ 10, 2, 8, 4, 7, 6, 1, 5, 15, 11, 9, 14, 3, 12, 13, 0 },
 };
 
-static inline void blake2s_increment_counter(struct blake2s_ctx *ctx,
-					     const u32 inc)
+static inline void blake2s_increment_counter(struct blake2s_ctx *ctx, u32 inc)
 {
 	ctx->t[0] += inc;
 	ctx->t[1] += (ctx->t[0] < inc);
 }
 
 static void __maybe_unused
-blake2s_compress_generic(struct blake2s_ctx *ctx, const u8 *block,
-			 size_t nblocks, const u32 inc)
+blake2s_compress_generic(struct blake2s_ctx *ctx,
+			 const u8 *data, size_t nblocks, u32 inc)
 {
 	u32 m[16];
 	u32 v[16];
@@ -49,7 +48,7 @@ blake2s_compress_generic(struct blake2s_ctx *ctx, const u8 *block,
 
 	while (nblocks > 0) {
 		blake2s_increment_counter(ctx, inc);
-		memcpy(m, block, BLAKE2S_BLOCK_SIZE);
+		memcpy(m, data, BLAKE2S_BLOCK_SIZE);
 		le32_to_cpu_array(m, ARRAY_SIZE(m));
 		memcpy(v, ctx->h, 32);
 		v[ 8] = BLAKE2S_IV0;
@@ -99,7 +98,7 @@ blake2s_compress_generic(struct blake2s_ctx *ctx, const u8 *block,
 		for (i = 0; i < 8; ++i)
 			ctx->h[i] ^= v[i] ^ v[i + 8];
 
-		block += BLAKE2S_BLOCK_SIZE;
+		data += BLAKE2S_BLOCK_SIZE;
 		--nblocks;
 	}
 }
@@ -130,6 +129,7 @@ void blake2s_update(struct blake2s_ctx *ctx, const u8 *in, size_t inlen)
 	}
 	if (inlen > BLAKE2S_BLOCK_SIZE) {
 		const size_t nblocks = DIV_ROUND_UP(inlen, BLAKE2S_BLOCK_SIZE);
+
 		blake2s_compress(ctx, in, nblocks - 1, BLAKE2S_BLOCK_SIZE);
 		in += BLAKE2S_BLOCK_SIZE * (nblocks - 1);
 		inlen -= BLAKE2S_BLOCK_SIZE * (nblocks - 1);
diff --git a/lib/crypto/x86/blake2s.h b/lib/crypto/x86/blake2s.h
index de360935b820..f8eed6cb042e 100644
--- a/lib/crypto/x86/blake2s.h
+++ b/lib/crypto/x86/blake2s.h
@@ -12,23 +12,21 @@
 #include <linux/sizes.h>
 
 asmlinkage void blake2s_compress_ssse3(struct blake2s_ctx *ctx,
-				       const u8 *block, const size_t nblocks,
-				       const u32 inc);
+				       const u8 *data, size_t nblocks, u32 inc);
 asmlinkage void blake2s_compress_avx512(struct blake2s_ctx *ctx,
-					const u8 *block, const size_t nblocks,
-					const u32 inc);
+					const u8 *data, size_t nblocks, u32 inc);
 
 static __ro_after_init DEFINE_STATIC_KEY_FALSE(blake2s_use_ssse3);
 static __ro_after_init DEFINE_STATIC_KEY_FALSE(blake2s_use_avx512);
 
-static void blake2s_compress(struct blake2s_ctx *ctx, const u8 *block,
-			     size_t nblocks, const u32 inc)
+static void blake2s_compress(struct blake2s_ctx *ctx,
+			     const u8 *data, size_t nblocks, u32 inc)
 {
 	/* SIMD disables preemption, so relax after processing each page. */
 	BUILD_BUG_ON(SZ_4K / BLAKE2S_BLOCK_SIZE < 8);
 
 	if (!static_branch_likely(&blake2s_use_ssse3) || !may_use_simd()) {
-		blake2s_compress_generic(ctx, block, nblocks, inc);
+		blake2s_compress_generic(ctx, data, nblocks, inc);
 		return;
 	}
 
@@ -38,13 +36,13 @@ static void blake2s_compress(struct blake2s_ctx *ctx, const u8 *block,
 
 		kernel_fpu_begin();
 		if (static_branch_likely(&blake2s_use_avx512))
-			blake2s_compress_avx512(ctx, block, blocks, inc);
+			blake2s_compress_avx512(ctx, data, blocks, inc);
 		else
-			blake2s_compress_ssse3(ctx, block, blocks, inc);
+			blake2s_compress_ssse3(ctx, data, blocks, inc);
 		kernel_fpu_end();
 
+		data += blocks * BLAKE2S_BLOCK_SIZE;
 		nblocks -= blocks;
-		block += blocks * BLAKE2S_BLOCK_SIZE;
 	} while (nblocks);
 }