From 649274d993212e7c23c0cb734572c2311c200872 Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Sun, 11 Jan 2009 00:20:39 -0800 Subject: net_dma: acquire/release dma channels on ifup/ifdown The recent dmaengine rework removed the capability to remove dma device driver modules while net_dma is active. Rather than notify dmaengine-clients that channels are trying to be removed, we now rely on clients to notify dmaengine when they no longer have a need for channels. Teach net_dma to release channels by taking dmaengine references at netdevice open and dropping references at netdevice close. Acked-by: Maciej Sosnowski Signed-off-by: Dan Williams Signed-off-by: David S. Miller --- net/core/dev.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) (limited to 'net/core/dev.c') diff --git a/net/core/dev.c b/net/core/dev.c index 5f736f1ceeae..b715a55cccc4 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -1087,6 +1087,11 @@ int dev_open(struct net_device *dev) */ dev->flags |= IFF_UP; + /* + * Enable NET_DMA + */ + dmaengine_get(); + /* * Initialize multicasting status */ @@ -1164,6 +1169,11 @@ int dev_close(struct net_device *dev) */ call_netdevice_notifiers(NETDEV_DOWN, dev); + /* + * Shutdown NET_DMA + */ + dmaengine_put(); + return 0; } @@ -5151,9 +5161,6 @@ static int __init net_dev_init(void) hotcpu_notifier(dev_cpu_callback, 0); dst_init(); dev_mcast_init(); - #ifdef CONFIG_NET_DMA - dmaengine_get(); - #endif rc = 0; out: return rc; -- cgit From f17f5c91ae3bfeb5cfc37fa132a5fdfceb8927be Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Wed, 14 Jan 2009 14:36:12 -0800 Subject: gro: Check for GSO packets and packets with frag_list As GRO cannot be applied to packets with frag_list we need to make sure that we reject such packets if they are fed to us, e.g., through a tunnel device. Also there is no point in applying GRO on GSO packets so they too should be rejected. This allows GRO to be used in virtio-net which may produce GSO packets directly but may still benefit from GRO if the other end of it doesn't support GSO. Signed-off-by: Herbert Xu Signed-off-by: David S. Miller --- net/core/dev.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'net/core/dev.c') diff --git a/net/core/dev.c b/net/core/dev.c index b715a55cccc4..7dec715293b1 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -2392,6 +2392,9 @@ int dev_gro_receive(struct napi_struct *napi, struct sk_buff *skb) if (!(skb->dev->features & NETIF_F_GRO)) goto normal; + if (skb_is_gso(skb) || skb_shinfo(skb)->frag_list) + goto normal; + rcu_read_lock(); list_for_each_entry_rcu(ptype, head, list) { struct sk_buff *p; -- cgit From f557206800801410c30e53ce7a27219b2c4cf0ba Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Wed, 14 Jan 2009 20:40:03 -0800 Subject: gro: Fix page ref count for skbs freed normally When an skb with page frags is merged into an existing one, we cannibalise its reference count. This is OK when the skb is reused because we set nr_frags to zero in that case. However, for the case where the skb is freed through kfree_skb, we didn't clear nr_frags which causes the page to be freed prematurely. This is fixed by moving the skb resetting into skb_gro_receive. Reported-by: Jeff Kirsher Signed-off-by: Herbert Xu Signed-off-by: David S. Miller --- net/core/dev.c | 6 ------ 1 file changed, 6 deletions(-) (limited to 'net/core/dev.c') diff --git a/net/core/dev.c b/net/core/dev.c index 7dec715293b1..60377b6c0a80 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -2491,12 +2491,6 @@ EXPORT_SYMBOL(napi_gro_receive); void napi_reuse_skb(struct napi_struct *napi, struct sk_buff *skb) { - skb_shinfo(skb)->nr_frags = 0; - - skb->len -= skb->data_len; - skb->truesize -= skb->data_len; - skb->data_len = 0; - __skb_pull(skb, skb_headlen(skb)); skb_reserve(skb, NET_IP_ALIGN - skb_headroom(skb)); -- cgit From 937f1ba56b4be37d9e2ad77412f95048662058d2 Mon Sep 17 00:00:00 2001 From: Benjamin Herrenschmidt Date: Wed, 14 Jan 2009 21:05:05 -0800 Subject: net: Add init_dummy_netdev() and fix EMAC driver using it This adds an init_dummy_netdev() function that gets a network device structure (allocation and lifetime entirely under caller's control) and initialize the minimum amount of fields so it can be used to schedule NAPI polls without registering a full blown interface. This is to be used by drivers that need to tie several hardware interfaces to a single NAPI poll scheduler due to HW limitations. It also updates the ibm_newemac driver to use that, this fixing the oops on 2.6.29 due to passing NULL as "dev" to netif_napi_add() Symbol is exported GPL only a I don't think we want binary drivers doing that sort of acrobatics (if we want them at all). Signed-off-by: Benjamin Herrenschmidt Tested-by: Geert Uytterhoeven Signed-off-by: David S. Miller --- net/core/dev.c | 39 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 39 insertions(+) (limited to 'net/core/dev.c') diff --git a/net/core/dev.c b/net/core/dev.c index 60377b6c0a80..8d675975d85b 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -4430,6 +4430,45 @@ err_uninit: goto out; } +/** + * init_dummy_netdev - init a dummy network device for NAPI + * @dev: device to init + * + * This takes a network device structure and initialize the minimum + * amount of fields so it can be used to schedule NAPI polls without + * registering a full blown interface. This is to be used by drivers + * that need to tie several hardware interfaces to a single NAPI + * poll scheduler due to HW limitations. + */ +int init_dummy_netdev(struct net_device *dev) +{ + /* Clear everything. Note we don't initialize spinlocks + * are they aren't supposed to be taken by any of the + * NAPI code and this dummy netdev is supposed to be + * only ever used for NAPI polls + */ + memset(dev, 0, sizeof(struct net_device)); + + /* make sure we BUG if trying to hit standard + * register/unregister code path + */ + dev->reg_state = NETREG_DUMMY; + + /* initialize the ref count */ + atomic_set(&dev->refcnt, 1); + + /* NAPI wants this */ + INIT_LIST_HEAD(&dev->napi_list); + + /* a dummy interface is started by default */ + set_bit(__LINK_STATE_PRESENT, &dev->state); + set_bit(__LINK_STATE_START, &dev->state); + + return 0; +} +EXPORT_SYMBOL_GPL(init_dummy_netdev); + + /** * register_netdev - register a network device * @dev: device to register -- cgit