[PATCH v2 1/6] crypto: arm64/crct10dif - Remove obsolete chunking logic

[Ard Biesheuvel <ardb+git@google.com>]

From: Ard Biesheuvel <ardb@kernel.org>

This is a partial revert of commit fc754c024a343b, which moved the logic
into C code which ensures that kernel mode NEON code does not hog the
CPU for too long.

This is no longer needed now that kernel mode NEON no longer disables
preemption, so we can drop this.

Reviewed-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
---
 arch/arm64/crypto/crct10dif-ce-glue.c | 30 ++++----------------
 1 file changed, 6 insertions(+), 24 deletions(-)

diff --git a/arch/arm64/crypto/crct10dif-ce-glue.c b/arch/arm64/crypto/crct10dif-ce-glue.c
index 606d25c559ed..7b05094a0480 100644
--- a/arch/arm64/crypto/crct10dif-ce-glue.c
+++ b/arch/arm64/crypto/crct10dif-ce-glue.c
@@ -37,18 +37,9 @@ static int crct10dif_update_pmull_p8(struct shash_desc *desc, const u8 *data,
 	u16 *crc = shash_desc_ctx(desc);
 
 	if (length >= CRC_T10DIF_PMULL_CHUNK_SIZE && crypto_simd_usable()) {
-		do {
-			unsigned int chunk = length;
-
-			if (chunk > SZ_4K + CRC_T10DIF_PMULL_CHUNK_SIZE)
-				chunk = SZ_4K;
-
-			kernel_neon_begin();
-			*crc = crc_t10dif_pmull_p8(*crc, data, chunk);
-			kernel_neon_end();
-			data += chunk;
-			length -= chunk;
-		} while (length);
+		kernel_neon_begin();
+		*crc = crc_t10dif_pmull_p8(*crc, data, length);
+		kernel_neon_end();
 	} else {
 		*crc = crc_t10dif_generic(*crc, data, length);
 	}
@@ -62,18 +53,9 @@ static int crct10dif_update_pmull_p64(struct shash_desc *desc, const u8 *data,
 	u16 *crc = shash_desc_ctx(desc);
 
 	if (length >= CRC_T10DIF_PMULL_CHUNK_SIZE && crypto_simd_usable()) {
-		do {
-			unsigned int chunk = length;
-
-			if (chunk > SZ_4K + CRC_T10DIF_PMULL_CHUNK_SIZE)
-				chunk = SZ_4K;
-
-			kernel_neon_begin();
-			*crc = crc_t10dif_pmull_p64(*crc, data, chunk);
-			kernel_neon_end();
-			data += chunk;
-			length -= chunk;
-		} while (length);
+		kernel_neon_begin();
+		*crc = crc_t10dif_pmull_p64(*crc, data, length);
+		kernel_neon_end();
 	} else {
 		*crc = crc_t10dif_generic(*crc, data, length);
 	}
-- 
2.47.0.199.ga7371fff76-goog