Merge branch 'napi_budget_zero'

Eric W. Biederman says:

====================
Don't receive packets when the napi budget == 0

After reading through all 120 drivers supporting netpoll I have found 16
more that process at least received packet when the napi budget == 0.

Processing more packets than your budget has always been a bug but
we haven't cared before so it looks like these drivers slipped through,
and need fixes.

As netpoll will shortly be using a budget of 0 to get the tx queue
processing with the rx queue processing we now care.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/amd/amd8111e.c

@@ -720,6 +720,9 @@ static int amd8111e_rx_poll(struct napi_struct *napi, int budget)
 	int rx_pkt_limit = budget;
 	unsigned long flags;
 
+	if (rx_pkt_limit <= 0)
+		goto rx_not_empty;
+
 	do{
 		/* process receive packets until we use the quota*/
 		/* If we own the next entry, it's a new packet. Send it up. */

drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c

@@ -872,6 +872,8 @@ static int bnx2x_rx_int(struct bnx2x_fastpath *fp, int budget)
 	if (unlikely(bp->panic))
 		return 0;
 #endif
+	if (budget <= 0)
+		return rx_pkt;
 
 	bd_cons = fp->rx_bd_cons;
 	bd_prod = fp->rx_bd_prod;

drivers/net/ethernet/cisco/enic/enic_main.c

@@ -1086,14 +1086,15 @@ static int enic_poll(struct napi_struct *napi, int budget)
 	unsigned int intr = enic_legacy_io_intr();
 	unsigned int rq_work_to_do = budget;
 	unsigned int wq_work_to_do = -1; /* no limit */
-	unsigned int  work_done, rq_work_done, wq_work_done;
+	unsigned int  work_done, rq_work_done = 0, wq_work_done;
 	int err;
 
 	/* Service RQ (first) and WQ
 	 */
 
-	rq_work_done = vnic_cq_service(&enic->cq[cq_rq],
-		rq_work_to_do, enic_rq_service, NULL);
+	if (budget > 0)
+		rq_work_done = vnic_cq_service(&enic->cq[cq_rq],
+			rq_work_to_do, enic_rq_service, NULL);
 
 	wq_work_done = vnic_cq_service(&enic->cq[cq_wq],
 		wq_work_to_do, enic_wq_service, NULL);
@@ -1141,14 +1142,15 @@ static int enic_poll_msix(struct napi_struct *napi, int budget)
 	unsigned int cq = enic_cq_rq(enic, rq);
 	unsigned int intr = enic_msix_rq_intr(enic, rq);
 	unsigned int work_to_do = budget;
-	unsigned int work_done;
+	unsigned int work_done = 0;
 	int err;
 
 	/* Service RQ
 	 */
 
-	work_done = vnic_cq_service(&enic->cq[cq],
-		work_to_do, enic_rq_service, NULL);
+	if (budget > 0)
+		work_done = vnic_cq_service(&enic->cq[cq],
+			work_to_do, enic_rq_service, NULL);
 
 	/* Return intr event credits for this polling
 	 * cycle.  An intr event is the completion of a

drivers/net/ethernet/freescale/fs_enet/fs_enet-main.c

@@ -91,6 +91,9 @@ static int fs_enet_rx_napi(struct napi_struct *napi, int budget)
 	u16 pkt_len, sc;
 	int curidx;
 
+	if (budget <= 0)
+		return received;
+
 	/*
 	 * First, grab all of the stats for the incoming packet.
 	 * These get messed up if we get called due to a busy condition.

drivers/net/ethernet/ibm/ibmveth.c

@@ -1072,7 +1072,7 @@ static int ibmveth_poll(struct napi_struct *napi, int budget)
 	unsigned long lpar_rc;
 
 restart_poll:
-	do {
+	while (frames_processed < budget) {
 		if (!ibmveth_rxq_pending_buffer(adapter))
 			break;
 
@@ -1121,7 +1121,7 @@ static int ibmveth_poll(struct napi_struct *napi, int budget)
 			netdev->stats.rx_bytes += length;
 			frames_processed++;
 		}
-	} while (frames_processed < budget);
+	}
 
 	ibmveth_replenish_task(adapter);
 

drivers/net/ethernet/intel/i40e/i40e_txrx.c

@@ -1302,6 +1302,9 @@ static int i40e_clean_rx_irq(struct i40e_ring *rx_ring, int budget)
 	u8 rx_ptype;
 	u64 qword;
 
+	if (budget <= 0)
+		return 0;
+
 	rx_desc = I40E_RX_DESC(rx_ring, i);
 	qword = le64_to_cpu(rx_desc->wb.qword1.status_error_len);
 	rx_status = (qword & I40E_RXD_QW1_STATUS_MASK) >>

drivers/net/ethernet/intel/igb/igb_main.c

@@ -6946,7 +6946,7 @@ static bool igb_clean_rx_irq(struct igb_q_vector *q_vector, const int budget)
 	unsigned int total_bytes = 0, total_packets = 0;
 	u16 cleaned_count = igb_desc_unused(rx_ring);
 
-	do {
+	while (likely(total_packets < budget)) {
 		union e1000_adv_rx_desc *rx_desc;
 
 		/* return some buffers to hardware, one at a time is too slow */
@@ -6998,7 +6998,7 @@ static bool igb_clean_rx_irq(struct igb_q_vector *q_vector, const int budget)
 
 		/* update budget accounting */
 		total_packets++;
-	} while (likely(total_packets < budget));
+	}
 
 	/* place incomplete frames back on ring for completion */
 	rx_ring->skb = skb;

drivers/net/ethernet/intel/ixgbe/ixgbe_main.c

@@ -2076,7 +2076,7 @@ static int ixgbe_clean_rx_irq(struct ixgbe_q_vector *q_vector,
 #endif /* IXGBE_FCOE */
 	u16 cleaned_count = ixgbe_desc_unused(rx_ring);
 
-	do {
+	while (likely(total_rx_packets < budget)) {
 		union ixgbe_adv_rx_desc *rx_desc;
 		struct sk_buff *skb;
 
@@ -2151,7 +2151,7 @@ static int ixgbe_clean_rx_irq(struct ixgbe_q_vector *q_vector,
 
 		/* update budget accounting */
 		total_rx_packets++;
-	} while (likely(total_rx_packets < budget));
+	}
 
 	u64_stats_update_begin(&rx_ring->syncp);
 	rx_ring->stats.packets += total_rx_packets;

drivers/net/ethernet/marvell/sky2.c

@@ -2735,6 +2735,9 @@ static int sky2_status_intr(struct sky2_hw *hw, int to_do, u16 idx)
 	unsigned int total_bytes[2] = { 0 };
 	unsigned int total_packets[2] = { 0 };
 
+	if (to_do <= 0)
+		return work_done;
+
 	rmb();
 	do {
 		struct sky2_port *sky2;

drivers/net/ethernet/mellanox/mlx4/en_rx.c

@@ -661,6 +661,9 @@ int mlx4_en_process_rx_cq(struct net_device *dev, struct mlx4_en_cq *cq, int bud
 	if (!priv->port_up)
 		return 0;
 
+	if (budget <= 0)
+		return polled;
+
 	/* We assume a 1:1 mapping between CQEs and Rx descriptors, so Rx
 	 * descriptor offset can be deduced from the CQE index instead of
 	 * reading 'cqe->index' */

drivers/net/ethernet/neterion/s2io.c

@@ -2914,6 +2914,9 @@ static int rx_intr_handler(struct ring_info *ring_data, int budget)
 	struct RxD1 *rxdp1;
 	struct RxD3 *rxdp3;
 
+	if (budget <= 0)
+		return napi_pkts;
+
 	get_info = ring_data->rx_curr_get_info;
 	get_block = get_info.block_index;
 	memcpy(&put_info, &ring_data->rx_curr_put_info, sizeof(put_info));

drivers/net/ethernet/neterion/vxge/vxge-main.c

@@ -368,6 +368,9 @@ vxge_rx_1b_compl(struct __vxge_hw_ring *ringh, void *dtr,
 	vxge_debug_entryexit(VXGE_TRACE, "%s: %s:%d",
 		ring->ndev->name, __func__, __LINE__);
 
+	if (ring->budget <= 0)
+		goto out;
+
 	do {
 		prefetch((char *)dtr + L1_CACHE_BYTES);
 		rx_priv = vxge_hw_ring_rxd_private_get(dtr);
@@ -525,6 +528,7 @@ vxge_rx_1b_compl(struct __vxge_hw_ring *ringh, void *dtr,
 	if (first_dtr)
 		vxge_hw_ring_rxd_post_post_wmb(ringh, first_dtr);
 
+out:
 	vxge_debug_entryexit(VXGE_TRACE,
 				"%s:%d  Exiting...",
 				__func__, __LINE__);

drivers/net/ethernet/sfc/ef10.c

@@ -1955,6 +1955,9 @@ static int efx_ef10_ev_process(struct efx_channel *channel, int quota)
 	int tx_descs = 0;
 	int spent = 0;
 
+	if (quota <= 0)
+		return spent;
+
 	read_ptr = channel->eventq_read_ptr;
 
 	for (;;) {

drivers/net/ethernet/sfc/farch.c

@@ -1248,6 +1248,9 @@ int efx_farch_ev_process(struct efx_channel *channel, int budget)
 	int tx_packets = 0;
 	int spent = 0;
 
+	if (budget <= 0)
+		return spent;
+
 	read_ptr = channel->eventq_read_ptr;
 
 	for (;;) {

drivers/net/ethernet/tile/tilegx.c

@@ -659,6 +659,9 @@ static int tile_net_poll(struct napi_struct *napi, int budget)
 	struct info_mpipe *info_mpipe =
 		container_of(napi, struct info_mpipe, napi);
 
+	if (budget <= 0)
+		goto done;
+
 	instance = info_mpipe->instance;
 	while ((n = gxio_mpipe_iqueue_try_peek(
 			&info_mpipe->iqueue,

drivers/net/ethernet/tile/tilepro.c

@@ -831,6 +831,9 @@ static int tile_net_poll(struct napi_struct *napi, int budget)
 
 	unsigned int work = 0;
 
+	if (budget <= 0)
+		goto done;
+
 	while (priv->active) {
 		int index = qup->__packet_receive_read;
 		if (index == qsp->__packet_receive_queue.__packet_write)

drivers/net/ethernet/toshiba/tc35815.c

@@ -1645,6 +1645,9 @@ static int tc35815_poll(struct napi_struct *napi, int budget)
 	int received = 0, handled;
 	u32 status;
 
+	if (budget <= 0)
+		return received;
+
 	spin_lock(&lp->rx_lock);
 	status = tc_readl(&tr->Int_Src);
 	do {