From db21733488f84a596faaad0d05430b3f51804692 Mon Sep 17 00:00:00 2001 From: Chris Leech Date: Sat, 17 Jun 2006 21:24:58 -0700 Subject: [I/OAT]: Setup the networking subsystem as a DMA client Attempts to allocate per-CPU DMA channels Signed-off-by: Chris Leech Signed-off-by: David S. Miller --- include/linux/netdevice.h | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'include/linux/netdevice.h') diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index f4169bbb60eb..b5760c67af9c 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -37,6 +37,7 @@ #include #include #include +#include struct divert_blk; struct vlan_group; @@ -593,6 +594,9 @@ struct softnet_data struct sk_buff *completion_queue; struct net_device backlog_dev; /* Sorry. 8) */ +#ifdef CONFIG_NET_DMA + struct dma_chan *net_dma; +#endif }; DECLARE_PER_CPU(struct softnet_data,softnet_data); -- cgit v1.2.3 From 932ff279a43ab7257942cddff2595acd541cc49b Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Fri, 9 Jun 2006 12:20:56 -0700 Subject: [NET]: Add netif_tx_lock Various drivers use xmit_lock internally to synchronise with their transmission routines. They do so without setting xmit_lock_owner. This is fine as long as netpoll is not in use. With netpoll it is possible for deadlocks to occur if xmit_lock_owner isn't set. This is because if a printk occurs while xmit_lock is held and xmit_lock_owner is not set can cause netpoll to attempt to take xmit_lock recursively. While it is possible to resolve this by getting netpoll to use trylock, it is suboptimal because netpoll's sole objective is to maximise the chance of getting the printk out on the wire. So delaying or dropping the message is to be avoided as much as possible. So the only alternative is to always set xmit_lock_owner. The following patch does this by introducing the netif_tx_lock family of functions that take care of setting/unsetting xmit_lock_owner. I renamed xmit_lock to _xmit_lock to indicate that it should not be used directly. I didn't provide irq versions of the netif_tx_lock functions since xmit_lock is meant to be a BH-disabling lock. This is pretty much a straight text substitution except for a small bug fix in winbond. It currently uses netif_stop_queue/spin_unlock_wait to stop transmission. This is unsafe as an IRQ can potentially wake up the queue. So it is safer to use netif_tx_disable. The hamradio bits used spin_lock_irq but it is unnecessary as xmit_lock must never be taken in an IRQ handler. Signed-off-by: Herbert Xu Signed-off-by: David S. Miller --- include/linux/netdevice.h | 38 +++++++++++++++++++++++++++++++++++--- 1 file changed, 35 insertions(+), 3 deletions(-) (limited to 'include/linux/netdevice.h') diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index b5760c67af9c..067b9ccafd87 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -407,7 +407,7 @@ struct net_device * One part is mostly used on xmit path (device) */ /* hard_start_xmit synchronizer */ - spinlock_t xmit_lock ____cacheline_aligned_in_smp; + spinlock_t _xmit_lock ____cacheline_aligned_in_smp; /* cpu id of processor entered to hard_start_xmit or -1, if nobody entered there. */ @@ -893,11 +893,43 @@ static inline void __netif_rx_complete(struct net_device *dev) clear_bit(__LINK_STATE_RX_SCHED, &dev->state); } +static inline void netif_tx_lock(struct net_device *dev) +{ + spin_lock(&dev->_xmit_lock); + dev->xmit_lock_owner = smp_processor_id(); +} + +static inline void netif_tx_lock_bh(struct net_device *dev) +{ + spin_lock_bh(&dev->_xmit_lock); + dev->xmit_lock_owner = smp_processor_id(); +} + +static inline int netif_tx_trylock(struct net_device *dev) +{ + int err = spin_trylock(&dev->_xmit_lock); + if (!err) + dev->xmit_lock_owner = smp_processor_id(); + return err; +} + +static inline void netif_tx_unlock(struct net_device *dev) +{ + dev->xmit_lock_owner = -1; + spin_unlock(&dev->_xmit_lock); +} + +static inline void netif_tx_unlock_bh(struct net_device *dev) +{ + dev->xmit_lock_owner = -1; + spin_unlock_bh(&dev->_xmit_lock); +} + static inline void netif_tx_disable(struct net_device *dev) { - spin_lock_bh(&dev->xmit_lock); + netif_tx_lock_bh(dev); netif_stop_queue(dev); - spin_unlock_bh(&dev->xmit_lock); + netif_tx_unlock_bh(dev); } /* These functions live elsewhere (drivers/net/net_init.c, but related) */ -- cgit v1.2.3 From 8648b3053bff39a7ee4c711d74268079c928a657 Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Sat, 17 Jun 2006 22:06:05 -0700 Subject: [NET]: Add NETIF_F_GEN_CSUM and NETIF_F_ALL_CSUM The current stack treats NETIF_F_HW_CSUM and NETIF_F_NO_CSUM identically so we test for them in quite a few places. For the sake of brevity, I'm adding the macro NETIF_F_GEN_CSUM for these two. We also test the disjunct of NETIF_F_IP_CSUM and the other two in various places, for that purpose I've added NETIF_F_ALL_CSUM. Signed-off-by: Herbert Xu Signed-off-by: David S. Miller --- include/linux/netdevice.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'include/linux/netdevice.h') diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 067b9ccafd87..e432b743dda2 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -312,6 +312,9 @@ struct net_device #define NETIF_F_LLTX 4096 /* LockLess TX */ #define NETIF_F_UFO 8192 /* Can offload UDP Large Send*/ +#define NETIF_F_GEN_CSUM (NETIF_F_NO_CSUM | NETIF_F_HW_CSUM) +#define NETIF_F_ALL_CSUM (NETIF_F_IP_CSUM | NETIF_F_GEN_CSUM) + struct net_device *next_sched; /* Interface index. Unique device identifier */ -- cgit v1.2.3