From 362108b5adddac6f496acc40696e499defd56d62 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Thu, 2 Feb 2017 10:50:48 -0800 Subject: [PATCH] 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 Signed-off-by: David S. Miller --- .../net/ethernet/myricom/myri10ge/myri10ge.c | 197 +----------------- 1 file changed, 4 insertions(+), 193 deletions(-) diff --git a/drivers/net/ethernet/myricom/myri10ge/myri10ge.c b/drivers/net/ethernet/myricom/myri10ge/myri10ge.c index 3d881176a353..1139d1803e7e 100644 --- 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) -- 2.30.2