Skip to main content

Browse the archive

Revision 231c807a60715312e2a93a001cc9be9b888bc350 authored by Linus Torvalds on 24 March 2019, 18:42:10 UTC, committed by Linus Torvalds on 24 March 2019, 18:42:10 UTC 
Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
 
Pull scheduler updates from Thomas Gleixner:
 "Third more careful attempt for this set of fixes:

   - Prevent a 32bit math overflow in the cpufreq code

   - Fix a buffer overflow when scanning the cgroup2 cpu.max property

   - A set of fixes for the NOHZ scheduler logic to prevent waking up
     CPUs even if the capacity of the busy CPUs is sufficient along with
     other tweaks optimizing the behaviour for asymmetric systems
     (big/little)"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/fair: Skip LLC NOHZ logic for asymmetric systems
  sched/fair: Tune down misfit NOHZ kicks
  sched/fair: Comment some nohz_balancer_kick() kick conditions
  sched/core: Fix buffer overflow in cgroup2 property cpu.max
  sched/cpufreq: Fix 32-bit math overflow
2 parent s 49ef015 + b9a7b88
Raw File
6lowpan.txt 

Netdev private dataroom for 6lowpan interfaces:

All 6lowpan able net devices, means all interfaces with ARPHRD_6LOWPAN,
must have "struct lowpan_priv" placed at beginning of netdev_priv.

The priv_size of each interface should be calculate by:

 dev->priv_size = LOWPAN_PRIV_SIZE(LL_6LOWPAN_PRIV_DATA);

Where LL_PRIV_6LOWPAN_DATA is sizeof linklayer 6lowpan private data struct.
To access the LL_PRIV_6LOWPAN_DATA structure you can cast:

 lowpan_priv(dev)-priv;

to your LL_6LOWPAN_PRIV_DATA structure.

Before registering the lowpan netdev interface you must run:

 lowpan_netdev_setup(dev, LOWPAN_LLTYPE_FOOBAR);

wheres LOWPAN_LLTYPE_FOOBAR is a define for your 6LoWPAN linklayer type of
enum lowpan_lltypes.

Example to evaluate the private usually you can do:

static inline struct lowpan_priv_foobar *
lowpan_foobar_priv(struct net_device *dev)
{
	return (struct lowpan_priv_foobar *)lowpan_priv(dev)->priv;
}

switch (dev->type) {
case ARPHRD_6LOWPAN:
	lowpan_priv = lowpan_priv(dev);
	/* do great stuff which is ARPHRD_6LOWPAN related */
	switch (lowpan_priv->lltype) {
	case LOWPAN_LLTYPE_FOOBAR:
		/* do 802.15.4 6LoWPAN handling here */
		lowpan_foobar_priv(dev)->bar = foo;
		break;
	...
	}
	break;
...
}

In case of generic 6lowpan branch ("net/6lowpan") you can remove the check
on ARPHRD_6LOWPAN, because you can be sure that these function are called
by ARPHRD_6LOWPAN interfaces.
back to top