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>

17 files changed, 53 insertions, 12 deletions

diff --git a/drivers/net/ethernet/amd/amd8111e.c b/drivers/net/ethernet/amd/amd8111e.c
index 2061b471fd16..26efaaa5e73f 100644
--- a/drivers/net/ethernet/amd/amd8111e.c
+++ b/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. */
diff --git a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c
index 117b5c7f8ac9..acd494647f25 100644
--- a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c
+++ b/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;
diff --git a/drivers/net/ethernet/cisco/enic/enic_main.c b/drivers/net/ethernet/cisco/enic/enic_main.c
index dcd58f23834a..4c35fc8fad99 100644
--- a/drivers/net/ethernet/cisco/enic/enic_main.c
+++ b/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
diff --git a/drivers/net/ethernet/freescale/fs_enet/fs_enet-main.c b/drivers/net/ethernet/freescale/fs_enet/fs_enet-main.c
index 62f042d4aaa9..dc80db41d6b3 100644
--- a/drivers/net/ethernet/freescale/fs_enet/fs_enet-main.c
+++ b/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.
diff --git a/drivers/net/ethernet/ibm/ibmveth.c b/drivers/net/ethernet/ibm/ibmveth.c
index 1fc8334fc181..e75bdfcd1374 100644
--- a/drivers/net/ethernet/ibm/ibmveth.c
+++ b/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 @@ restart_poll:
                         netdev->stats.rx_bytes += length;
                         frames_processed++;
                 }
-        } while (frames_processed < budget);
+        }
 
         ibmveth_replenish_task(adapter);
 
diff --git a/drivers/net/ethernet/intel/i40e/i40e_txrx.c b/drivers/net/ethernet/intel/i40e/i40e_txrx.c
index daa3b295ff3d..88666adb0743 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_txrx.c
+++ b/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) >>
diff --git a/drivers/net/ethernet/intel/igb/igb_main.c b/drivers/net/ethernet/intel/igb/igb_main.c
index f81d87cfcc8d..d6b11522fed7 100644
--- a/drivers/net/ethernet/intel/igb/igb_main.c
+++ b/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;
diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
index 5d314fe873bb..18cd8ca319ea 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
+++ b/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;
diff --git a/drivers/net/ethernet/marvell/sky2.c b/drivers/net/ethernet/marvell/sky2.c
index 5a5b23741179..d524676fdff4 100644
--- a/drivers/net/ethernet/marvell/sky2.c
+++ b/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;
diff --git a/drivers/net/ethernet/mellanox/mlx4/en_rx.c b/drivers/net/ethernet/mellanox/mlx4/en_rx.c
index 8afb72ec957d..ba049ae88749 100644
--- a/drivers/net/ethernet/mellanox/mlx4/en_rx.c
+++ b/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' */
diff --git a/drivers/net/ethernet/neterion/s2io.c b/drivers/net/ethernet/neterion/s2io.c
index 56e3a9d42bb2..d44fdb91808e 100644
--- a/drivers/net/ethernet/neterion/s2io.c
+++ b/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));
diff --git a/drivers/net/ethernet/neterion/vxge/vxge-main.c b/drivers/net/ethernet/neterion/vxge/vxge-main.c
index c5bb1ace4a74..11adc89959c1 100644
--- a/drivers/net/ethernet/neterion/vxge/vxge-main.c
+++ b/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__);
diff --git a/drivers/net/ethernet/sfc/ef10.c b/drivers/net/ethernet/sfc/ef10.c
index eb75675f6e32..651626e133f9 100644
--- a/drivers/net/ethernet/sfc/ef10.c
+++ b/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 (;;) {
diff --git a/drivers/net/ethernet/sfc/farch.c b/drivers/net/ethernet/sfc/farch.c
index aa1b169f45ec..a08761360cdf 100644
--- a/drivers/net/ethernet/sfc/farch.c
+++ b/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 (;;) {
diff --git a/drivers/net/ethernet/tile/tilegx.c b/drivers/net/ethernet/tile/tilegx.c
index 17503da9f7a5..b43f1b3b9632 100644
--- a/drivers/net/ethernet/tile/tilegx.c
+++ b/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,
diff --git a/drivers/net/ethernet/tile/tilepro.c b/drivers/net/ethernet/tile/tilepro.c
index 7e33973487ee..b94449b4bd34 100644
--- a/drivers/net/ethernet/tile/tilepro.c
+++ b/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)
diff --git a/drivers/net/ethernet/toshiba/tc35815.c b/drivers/net/ethernet/toshiba/tc35815.c
index 88e9c73cebc0..fef5573dbfca 100644
--- a/drivers/net/ethernet/toshiba/tc35815.c
+++ b/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 {