lib/crypto: arm64/gf128hash: Remove obsolete chunking logic

Since commit aefbab8 ("arm64: fpsimd: Preserve/restore kernel mode
NEON at context switch"), kernel-mode NEON sections have been
preemptible on arm64.  And since commit 7dadeaa ("sched: Further
restrict the preemption modes"), voluntary preemption is no longer
supported on arm64 either.  Therefore, there's no longer any need to
limit the length of kernel-mode NEON sections on arm64.

Simplify the GHASH and POLYVAL code accordingly.

Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20260401000548.133151-4-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@kernel.org>

Author: Eric Biggers

lib/crypto/arm64/gf128hash.h

@@ -89,16 +89,8 @@ static void ghash_blocks_arch(struct polyval_elem *acc,
 			      const u8 *data, size_t nblocks)
 {
 	if (static_branch_likely(&have_asimd) && may_use_simd()) {
-		do {
-			/* Allow rescheduling every 4 KiB. */
-			size_t n = min_t(size_t, nblocks,
-					 4096 / GHASH_BLOCK_SIZE);
-
-			scoped_ksimd()
-				pmull_ghash_update_p8(n, acc, data, &key->h);
-			data += n * GHASH_BLOCK_SIZE;
-			nblocks -= n;
-		} while (nblocks);
+		scoped_ksimd()
+			pmull_ghash_update_p8(nblocks, acc, data, &key->h);
 	} else {
 		ghash_blocks_generic(acc, &key->h, data, nblocks);
 	}
@@ -110,16 +102,8 @@ static void polyval_blocks_arch(struct polyval_elem *acc,
 				const u8 *data, size_t nblocks)
 {
 	if (static_branch_likely(&have_pmull) && may_use_simd()) {
-		do {
-			/* Allow rescheduling every 4 KiB. */
-			size_t n = min_t(size_t, nblocks,
-					 4096 / POLYVAL_BLOCK_SIZE);
-
-			scoped_ksimd()
-				polyval_blocks_pmull(acc, key, data, n);
-			data += n * POLYVAL_BLOCK_SIZE;
-			nblocks -= n;
-		} while (nblocks);
+		scoped_ksimd()
+			polyval_blocks_pmull(acc, key, data, nblocks);
 	} else {
 		polyval_blocks_generic(acc, &key->h_powers[NUM_H_POWERS - 1],
 				       data, nblocks);