Revert "net: macsec: preserve ingress frame ordering"

This reverts commit ab046a5.

It was trying to work around an issue at the crypto layer by excluding
ASYNC implementations of gcm(aes), because a bug in the AESNI version
caused reordering when some requests bypassed the cryptd queue while
older requests were still pending on the queue.

This was fixed by commit 38b2f68 ("crypto: aesni - Fix cryptd
reordering problem on gcm"), which pre-dates ab046a5.

Herbert Xu confirmed that all ASYNC implementations are expected to
maintain the ordering of completions wrt requests, so we can use them
in MACsec.

On my test machine, this restores the performance of a single netperf
instance, from 1.4Gbps to 4.4Gbps.

Link: https://lore.kernel.org/netdev/9328d206c5d9f9239cae27e62e74de40b258471d.1692279161.git.sd@queasysnail.net/T/
Link: https://lore.kernel.org/netdev/1b0cec71-d084-8153-2ba4-72ce71abeb65@byu.edu/
Link: https://lore.kernel.org/netdev/d335ddaa-18dc-f9f0-17ee-9783d3b2ca29@mailbox.tu-dresden.de/
Fixes: ab046a5 ("net: macsec: preserve ingress frame ordering")
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Link: https://lore.kernel.org/r/11c952469d114db6fb29242e1d9545e61f52f512.1693757159.git.sd@queasysnail.net
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

drivers/net/macsec.c

@@ -1330,8 +1330,7 @@ static struct crypto_aead *macsec_alloc_tfm(char *key, int key_len, int icv_len)
 	struct crypto_aead *tfm;
 	int ret;
 
-	/* Pick a sync gcm(aes) cipher to ensure order is preserved. */
-	tfm = crypto_alloc_aead("gcm(aes)", 0, CRYPTO_ALG_ASYNC);
+	tfm = crypto_alloc_aead("gcm(aes)", 0, 0);
 
 	if (IS_ERR(tfm))
 		return tfm;