crypto: arm64/aes-blk - yield NEON after every block of input

Avoid excessive scheduling delays under a preemptible kernel by
yielding the NEON after every block of input.

Signed-off-by: Ard Biesheuvel <[email protected]>
Signed-off-by: Herbert Xu <[email protected]>

Author: Ard Biesheuvel

arch/arm64/crypto/aes-ce.S

@@ -30,18 +30,21 @@
 	.endm
 
 	/* prepare for encryption with key in rk[] */
-	.macro		enc_prepare, rounds, rk, ignore
-	load_round_keys	\rounds, \rk
+	.macro		enc_prepare, rounds, rk, temp
+	mov		\temp, \rk
+	load_round_keys	\rounds, \temp
 	.endm
 
 	/* prepare for encryption (again) but with new key in rk[] */
-	.macro		enc_switch_key, rounds, rk, ignore
-	load_round_keys	\rounds, \rk
+	.macro		enc_switch_key, rounds, rk, temp
+	mov		\temp, \rk
+	load_round_keys	\rounds, \temp
 	.endm
 
 	/* prepare for decryption with key in rk[] */
-	.macro		dec_prepare, rounds, rk, ignore
-	load_round_keys	\rounds, \rk
+	.macro		dec_prepare, rounds, rk, temp
+	mov		\temp, \rk
+	load_round_keys	\rounds, \temp
 	.endm
 
 	.macro		do_enc_Nx, de, mc, k, i0, i1, i2, i3