myri10ge: get rid of custom busy poll code

Compared to custom busy_poll, the generic NAPI one is simpler and
removes a lot of code. It removes one atomic in the fast path (when
busy poll is not in action) since we do not have to use an extra
spinlock.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/myricom/myri10ge/myri10ge.c b/drivers/net/ethernet/myricom/myri10ge/myri10ge.c
index 3d881176a35392cdac0567f6dbdeb3d6b8835a81..1139d1803e7e483a72e4cc225207e68a5d61924a 100644 (file)
--- a/drivers/net/ethernet/myricom/myri10ge/myri10ge.c
+++ b/drivers/net/ethernet/myricom/myri10ge/myri10ge.c
@@ -191,21 +191,6 @@ struct myri10ge_slice_state {
        int cpu;
        __be32 __iomem *dca_tag;
 #endif
-#ifdef CONFIG_NET_RX_BUSY_POLL
-       unsigned int state;
-#define SLICE_STATE_IDLE       0
-#define SLICE_STATE_NAPI       1       /* NAPI owns this slice */
-#define SLICE_STATE_POLL       2       /* poll owns this slice */
-#define SLICE_LOCKED (SLICE_STATE_NAPI | SLICE_STATE_POLL)
-#define SLICE_STATE_NAPI_YIELD 4       /* NAPI yielded this slice */
-#define SLICE_STATE_POLL_YIELD 8       /* poll yielded this slice */
-#define SLICE_USER_PEND (SLICE_STATE_POLL | SLICE_STATE_POLL_YIELD)
-       spinlock_t lock;
-       unsigned long lock_napi_yield;
-       unsigned long lock_poll_yield;
-       unsigned long busy_poll_miss;
-       unsigned long busy_poll_cnt;
-#endif /* CONFIG_NET_RX_BUSY_POLL */
        char irq_desc[32];
 };
 
@@ -925,92 +910,6 @@ abort:
        return status;
 }
 
-#ifdef CONFIG_NET_RX_BUSY_POLL
-static inline void myri10ge_ss_init_lock(struct myri10ge_slice_state *ss)
-{
-       spin_lock_init(&ss->lock);
-       ss->state = SLICE_STATE_IDLE;
-}
-
-static inline bool myri10ge_ss_lock_napi(struct myri10ge_slice_state *ss)
-{
-       bool rc = true;
-       spin_lock(&ss->lock);
-       if ((ss->state & SLICE_LOCKED)) {
-               WARN_ON((ss->state & SLICE_STATE_NAPI));
-               ss->state |= SLICE_STATE_NAPI_YIELD;
-               rc = false;
-               ss->lock_napi_yield++;
-       } else
-               ss->state = SLICE_STATE_NAPI;
-       spin_unlock(&ss->lock);
-       return rc;
-}
-
-static inline void myri10ge_ss_unlock_napi(struct myri10ge_slice_state *ss)
-{
-       spin_lock(&ss->lock);
-       WARN_ON((ss->state & (SLICE_STATE_POLL | SLICE_STATE_NAPI_YIELD)));
-       ss->state = SLICE_STATE_IDLE;
-       spin_unlock(&ss->lock);
-}
-
-static inline bool myri10ge_ss_lock_poll(struct myri10ge_slice_state *ss)
-{
-       bool rc = true;
-       spin_lock_bh(&ss->lock);
-       if ((ss->state & SLICE_LOCKED)) {
-               ss->state |= SLICE_STATE_POLL_YIELD;
-               rc = false;
-               ss->lock_poll_yield++;
-       } else
-               ss->state |= SLICE_STATE_POLL;
-       spin_unlock_bh(&ss->lock);
-       return rc;
-}
-
-static inline void myri10ge_ss_unlock_poll(struct myri10ge_slice_state *ss)
-{
-       spin_lock_bh(&ss->lock);
-       WARN_ON((ss->state & SLICE_STATE_NAPI));
-       ss->state = SLICE_STATE_IDLE;
-       spin_unlock_bh(&ss->lock);
-}
-
-static inline bool myri10ge_ss_busy_polling(struct myri10ge_slice_state *ss)
-{
-       WARN_ON(!(ss->state & SLICE_LOCKED));
-       return (ss->state & SLICE_USER_PEND);
-}
-#else /* CONFIG_NET_RX_BUSY_POLL */
-static inline void myri10ge_ss_init_lock(struct myri10ge_slice_state *ss)
-{
-}
-
-static inline bool myri10ge_ss_lock_napi(struct myri10ge_slice_state *ss)
-{
-       return false;
-}
-
-static inline void myri10ge_ss_unlock_napi(struct myri10ge_slice_state *ss)
-{
-}
-
-static inline bool myri10ge_ss_lock_poll(struct myri10ge_slice_state *ss)
-{
-       return false;
-}
-
-static inline void myri10ge_ss_unlock_poll(struct myri10ge_slice_state *ss)
-{
-}
-
-static inline bool myri10ge_ss_busy_polling(struct myri10ge_slice_state *ss)
-{
-       return false;
-}
-#endif
-
 static int myri10ge_reset(struct myri10ge_priv *mgp)
 {
        struct myri10ge_cmd cmd;
@@ -1426,7 +1325,6 @@ myri10ge_rx_done(struct myri10ge_slice_state *ss, int len, __wsum csum)
        struct pci_dev *pdev = mgp->pdev;
        struct net_device *dev = mgp->dev;
        u8 *va;
-       bool polling;
 
        if (len <= mgp->small_bytes) {
                rx = &ss->rx_small;
@@ -1441,15 +1339,7 @@ myri10ge_rx_done(struct myri10ge_slice_state *ss, int len, __wsum csum)
        va = page_address(rx->info[idx].page) + rx->info[idx].page_offset;
        prefetch(va);
 
-       /* When busy polling in user context, allocate skb and copy headers to
-        * skb's linear memory ourselves.  When not busy polling, use the napi
-        * gro api.
-        */
-       polling = myri10ge_ss_busy_polling(ss);
-       if (polling)
-               skb = netdev_alloc_skb(dev, MYRI10GE_HLEN + 16);
-       else
-               skb = napi_get_frags(&ss->napi);
+       skb = napi_get_frags(&ss->napi);
        if (unlikely(skb == NULL)) {
                ss->stats.rx_dropped++;
                for (i = 0, remainder = len; remainder > 0; i++) {
@@ -1489,27 +1379,7 @@ myri10ge_rx_done(struct myri10ge_slice_state *ss, int len, __wsum csum)
        myri10ge_vlan_rx(mgp->dev, va, skb);
        skb_record_rx_queue(skb, ss - &mgp->ss[0]);
 
-       if (polling) {
-               int hlen;
-
-               /* myri10ge_vlan_rx might have moved the header, so compute
-                * length and address again.
-                */
-               hlen = MYRI10GE_HLEN > skb->len ? skb->len : MYRI10GE_HLEN;
-               va = page_address(skb_frag_page(&rx_frags[0])) +
-                       rx_frags[0].page_offset;
-               /* Copy header into the skb linear memory */
-               skb_copy_to_linear_data(skb, va, hlen);
-               rx_frags[0].page_offset += hlen;
-               rx_frags[0].size -= hlen;
-               skb->data_len -= hlen;
-               skb->tail += hlen;
-               skb->protocol = eth_type_trans(skb, dev);
-               skb_mark_napi_id(skb, &ss->napi);
-               netif_receive_skb(skb);
-       }
-       else
-               napi_gro_frags(&ss->napi);
+       napi_gro_frags(&ss->napi);
 
        return 1;
 }
@@ -1669,14 +1539,9 @@ static int myri10ge_poll(struct napi_struct *napi, int budget)
        if (ss->mgp->dca_enabled)
                myri10ge_update_dca(ss);
 #endif
-       /* Try later if the busy_poll handler is running. */
-       if (!myri10ge_ss_lock_napi(ss))
-               return budget;
-
        /* process as many rx events as NAPI will allow */
        work_done = myri10ge_clean_rx_done(ss, budget);
 
-       myri10ge_ss_unlock_napi(ss);
        if (work_done < budget) {
                napi_complete_done(napi, work_done);
                put_be32(htonl(3), ss->irq_claim);
@@ -1684,34 +1549,6 @@ static int myri10ge_poll(struct napi_struct *napi, int budget)
        return work_done;
 }
 
-#ifdef CONFIG_NET_RX_BUSY_POLL
-static int myri10ge_busy_poll(struct napi_struct *napi)
-{
-       struct myri10ge_slice_state *ss =
-           container_of(napi, struct myri10ge_slice_state, napi);
-       struct myri10ge_priv *mgp = ss->mgp;
-       int work_done;
-
-       /* Poll only when the link is up */
-       if (mgp->link_state != MXGEFW_LINK_UP)
-               return LL_FLUSH_FAILED;
-
-       if (!myri10ge_ss_lock_poll(ss))
-               return LL_FLUSH_BUSY;
-
-       /* Process a small number of packets */
-       work_done = myri10ge_clean_rx_done(ss, 4);
-       if (work_done)
-               ss->busy_poll_cnt += work_done;
-       else
-               ss->busy_poll_miss++;
-
-       myri10ge_ss_unlock_poll(ss);
-
-       return work_done;
-}
-#endif /* CONFIG_NET_RX_BUSY_POLL */
-
 static irqreturn_t myri10ge_intr(int irq, void *arg)
 {
        struct myri10ge_slice_state *ss = arg;
@@ -1919,10 +1756,6 @@ static const char myri10ge_gstrings_slice_stats[][ETH_GSTRING_LEN] = {
        "tx_pkt_start", "tx_pkt_done", "tx_req", "tx_done",
        "rx_small_cnt", "rx_big_cnt",
        "wake_queue", "stop_queue", "tx_linearized",
-#ifdef CONFIG_NET_RX_BUSY_POLL
-       "rx_lock_napi_yield", "rx_lock_poll_yield", "rx_busy_poll_miss",
-       "rx_busy_poll_cnt",
-#endif
 };
 
 #define MYRI10GE_NET_STATS_LEN      21
@@ -2022,12 +1855,6 @@ myri10ge_get_ethtool_stats(struct net_device *netdev,
                data[i++] = (unsigned int)ss->tx.wake_queue;
                data[i++] = (unsigned int)ss->tx.stop_queue;
                data[i++] = (unsigned int)ss->tx.linearized;
-#ifdef CONFIG_NET_RX_BUSY_POLL
-               data[i++] = ss->lock_napi_yield;
-               data[i++] = ss->lock_poll_yield;
-               data[i++] = ss->busy_poll_miss;
-               data[i++] = ss->busy_poll_cnt;
-#endif
        }
 }
 
@@ -2589,9 +2416,6 @@ static int myri10ge_open(struct net_device *dev)
                        goto abort_with_rings;
                }
 
-               /* Initialize the slice spinlock and state used for polling */
-               myri10ge_ss_init_lock(ss);
-
                /* must happen prior to any irq */
                napi_enable(&(ss)->napi);
        }
@@ -2668,19 +2492,9 @@ static int myri10ge_close(struct net_device *dev)
 
        del_timer_sync(&mgp->watchdog_timer);
        mgp->running = MYRI10GE_ETH_STOPPING;
-       for (i = 0; i < mgp->num_slices; i++) {
+       for (i = 0; i < mgp->num_slices; i++)
                napi_disable(&mgp->ss[i].napi);
-               local_bh_disable(); /* myri10ge_ss_lock_napi needs this */
-               /* Lock the slice to prevent the busy_poll handler from
-                * accessing it.  Later when we bring the NIC up, myri10ge_open
-                * resets the slice including this lock.
-                */
-               while (!myri10ge_ss_lock_napi(&mgp->ss[i])) {
-                       pr_info("Slice %d locked\n", i);
-                       mdelay(1);
-               }
-               local_bh_enable();
-       }
+
        netif_carrier_off(dev);
 
        netif_tx_stop_all_queues(dev);
@@ -3953,9 +3767,6 @@ static const struct net_device_ops myri10ge_netdev_ops = {
        .ndo_change_mtu         = myri10ge_change_mtu,
        .ndo_set_rx_mode        = myri10ge_set_multicast_list,
        .ndo_set_mac_address    = myri10ge_set_mac_address,
-#ifdef CONFIG_NET_RX_BUSY_POLL
-       .ndo_busy_poll          = myri10ge_busy_poll,
-#endif
 };
 
 static int myri10ge_probe(struct pci_dev *pdev, const struct pci_device_id *ent)