net/af_iucv: remove GFP_DMA restriction for HiperTransport

commit fdbf6326 upstream.

af_iucv sockets over z/VM IUCV require that their skbs are allocated
in DMA memory. This restriction doesn't apply to connections over
HiperSockets. So only set this limit for z/VM IUCV sockets, thereby
increasing the likelihood that the large (and linear!) allocations for
HiperTransport messages succeed.

Fixes: 3881ac44 ("af_iucv: add HiperSockets transport")
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Reviewed-by: Hendrik Brueckner <brueckner@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

net/iucv/af_iucv.c

@@ -568,7 +568,6 @@ static struct sock *iucv_sock_alloc(struct socket *sock, int proto, gfp_t prio)
 
 	sk->sk_destruct = iucv_sock_destruct;
 	sk->sk_sndtimeo = IUCV_CONN_TIMEOUT;
-	sk->sk_allocation = GFP_DMA;
 
 	sock_reset_flag(sk, SOCK_ZAPPED);
 
@@ -762,6 +761,7 @@ static int iucv_sock_bind(struct socket *sock, struct sockaddr *addr,
 		memcpy(iucv->src_user_id, iucv_userid, 8);
 		sk->sk_state = IUCV_BOUND;
 		iucv->transport = AF_IUCV_TRANS_IUCV;
+		sk->sk_allocation |= GFP_DMA;
 		if (!iucv->msglimit)
 			iucv->msglimit = IUCV_QUEUELEN_DEFAULT;
 		goto done_unlock;
@@ -786,6 +786,8 @@ static int iucv_sock_autobind(struct sock *sk)
 		return -EPROTO;
 
 	memcpy(iucv->src_user_id, iucv_userid, 8);
+	iucv->transport = AF_IUCV_TRANS_IUCV;
+	sk->sk_allocation |= GFP_DMA;
 
 	write_lock_bh(&iucv_sk_list.lock);
 	__iucv_auto_name(iucv);
@@ -1737,6 +1739,8 @@ static int iucv_callback_connreq(struct iucv_path *path,
 
 	niucv = iucv_sk(nsk);
 	iucv_sock_init(nsk, sk);
+	niucv->transport = AF_IUCV_TRANS_IUCV;
+	nsk->sk_allocation |= GFP_DMA;
 
 	/* Set the new iucv_sock */
 	memcpy(niucv->dst_name, ipuser + 8, 8);