| Message ID | 1231906495.22571.79.camel@pasglop (mailing list archive) |
|---|---|
| State | Not Applicable, archived |
| Headers | show |
On Wed, 14 Jan 2009, Benjamin Herrenschmidt wrote: > 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 <benh@kernel.crashing.org> Thanks, this fixed my Sequoia! Tested-by: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com> > --- linux-work.orig/include/linux/netdevice.h 2009-01-13 16:13:41.000000000 +1100 > +++ linux-work/include/linux/netdevice.h 2009-01-14 14:13:24.000000000 +1100 > @@ -4434,6 +4434,45 @@ err_uninit: > } > > /** > + * init_dummy_netdev - init a dummy network device for NAPI > + * @dev: device to init > + * > + * This takes a network device structure and initialize the minimum ^^^^^^^^^^ initializes > + * 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 ^^^ as > + * NAPI code and this dummy netdev is supposed to be > + * only ever used for NAPI polls > + */ With kind regards, Geert Uytterhoeven Software Architect Sony Techsoft Centre Europe The Corporate Village · Da Vincilaan 7-D1 · B-1935 Zaventem · Belgium Phone: +32 (0)2 700 8453 Fax: +32 (0)2 700 8622 E-mail: Geert.Uytterhoeven@sonycom.com Internet: http://www.sony-europe.com/ A division of Sony Europe (Belgium) N.V. VAT BE 0413.825.160 · RPR Brussels Fortis · BIC GEBABEBB · IBAN BE41293037680010
From: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com> Date: Wed, 14 Jan 2009 11:00:05 +0100 (CET) > On Wed, 14 Jan 2009, Benjamin Herrenschmidt wrote: > > 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 <benh@kernel.crashing.org> > > Thanks, this fixed my Sequoia! > > Tested-by: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com> Applied, thanks everyone.
Index: linux-work/include/linux/netdevice.h =================================================================== --- linux-work.orig/include/linux/netdevice.h 2009-01-13 16:13:41.000000000 +1100 +++ linux-work/include/linux/netdevice.h 2009-01-14 14:13:24.000000000 +1100 @@ -795,6 +795,7 @@ struct net_device NETREG_UNREGISTERING, /* called unregister_netdevice */ NETREG_UNREGISTERED, /* completed unregister todo */ NETREG_RELEASED, /* called free_netdev */ + NETREG_DUMMY, /* dummy device for NAPI poll */ } reg_state; /* Called from unregister, can be used to call free_netdev */ @@ -1077,6 +1078,8 @@ extern void free_netdev(struct net_devi extern void synchronize_net(void); extern int register_netdevice_notifier(struct notifier_block *nb); extern int unregister_netdevice_notifier(struct notifier_block *nb); +extern int init_dummy_netdev(struct net_device *dev); + extern int call_netdevice_notifiers(unsigned long val, struct net_device *dev); extern struct net_device *dev_get_by_index(struct net *net, int ifindex); extern struct net_device *__dev_get_by_index(struct net *net, int ifindex); Index: linux-work/net/core/dev.c =================================================================== --- linux-work.orig/net/core/dev.c 2009-01-13 16:17:52.000000000 +1100 +++ linux-work/net/core/dev.c 2009-01-14 14:24:03.000000000 +1100 @@ -4434,6 +4434,45 @@ err_uninit: } /** + * 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 * Index: linux-work/drivers/net/ibm_newemac/mal.c =================================================================== --- linux-work.orig/drivers/net/ibm_newemac/mal.c 2009-01-14 14:25:10.000000000 +1100 +++ linux-work/drivers/net/ibm_newemac/mal.c 2009-01-14 14:25:30.000000000 +1100 @@ -613,7 +613,9 @@ static int __devinit mal_probe(struct of INIT_LIST_HEAD(&mal->list); spin_lock_init(&mal->lock); - netif_napi_add(NULL, &mal->napi, mal_poll, + init_dummy_netdev(&mal->dummy_dev); + + netif_napi_add(&mal->dummy_dev, &mal->napi, mal_poll, CONFIG_IBM_NEW_EMAC_POLL_WEIGHT); /* Load power-on reset defaults */ Index: linux-work/drivers/net/ibm_newemac/mal.h =================================================================== --- linux-work.orig/drivers/net/ibm_newemac/mal.h 2009-01-14 14:24:40.000000000 +1100 +++ linux-work/drivers/net/ibm_newemac/mal.h 2009-01-14 14:24:58.000000000 +1100 @@ -214,6 +214,8 @@ struct mal_instance { int index; spinlock_t lock; + struct net_device dummy_dev; + unsigned int features; };
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 <benh@kernel.crashing.org> ---