linux-toradex.git/include/linux/netpoll.h, branch v2.6.27.50

[NETPOLL]: Revert two bogus cleanups that broke netconsole.

2008-03-04T20:28:49+00:00

Based upon a report by Andrew Morton and code analysis done
by Jarek Poplawski.

This reverts 33f807ba0d9259e7c75c7a2ce8bd2787e5b540c7 ("[NETPOLL]:
Kill NETPOLL_RX_DROP, set but never tested.")  and
c7b6ea24b43afb5749cb704e143df19d70e23dea ("[NETPOLL]: Don't need
rx_flags.").

The rx_flags did get tested for zero vs. non-zero and therefore we do
need those tests and that code which sets NETPOLL_RX_DROP et al.

Signed-off-by: David S. Miller

[NETPOLL]: Don't need rx_flags.

2008-01-28T22:54:18+00:00

The rx_flags variable is redundant. Turning rx on/off is done
via setting the rx_np pointer.

Signed-off-by: Stephen Hemminger 
Signed-off-by: David S. Miller

[NETPOLL]: no need to store local_mac

2008-01-28T22:54:17+00:00

The local_mac is managed by the network device, no need to keep a
spare copy and all the management problems that could cause.

Signed-off-by: Stephen Hemminger 
Signed-off-by: David S. Miller

[NET] netconsole: Support dynamic reconfiguration using configfs

2007-10-10T23:48:06+00:00

Based upon initial work by Keiichi Kii .

This patch introduces support for dynamic reconfiguration (adding, removing
and/or modifying parameters of netconsole targets at runtime) using a
userspace interface exported via configfs.  Documentation is also updated
accordingly.

Issues and brief design overview:

(1) Kernel-initiated creation / destruction of kernel objects is not
    possible with configfs -- the lifetimes of the "config items" is managed
    exclusively from userspace.  But netconsole must support boot/module
    params too, and these are parsed in kernel and hence netpolls must be
    setup from the kernel.  Joel Becker suggested to separately manage the
    lifetimes of the two kinds of netconsole_target objects -- those created
    via configfs mkdir(2) from userspace and those specified from the
    boot/module option string.  This adds complexity and some redundancy here
    and also means that boot/module param-created targets are not exposed
    through the configfs namespace (and hence cannot be updated / destroyed
    dynamically).  However, this saves us from locking / refcounting
    complexities that would need to be introduced in configfs to support
    kernel-initiated item creation / destroy there.

(2) In configfs, item creation takes place in the call chain of the
    mkdir(2) syscall in the driver subsystem.  If we used an ioctl(2) to
    create / destroy objects from userspace, the special userspace program is
    able to fill out the structure to be passed into the ioctl and hence
    specify attributes such as local interface that are required at the time
    we set up the netpoll.  For configfs, this information is not available at
    the time of mkdir(2).  So, we keep all newly-created targets (via
    configfs) disabled by default.  The user is expected to set various
    attributes appropriately (including the local network interface if
    required) and then write(2) "1" to the "enabled" attribute.  Thus,
    netpoll_setup() is then called on the set parameters in the context of
    _this_ write(2) on the "enabled" attribute itself.  This design enables
    the user to reconfigure existing netconsole targets at runtime to be
    attached to newly-come-up interfaces that may not have existed when
    netconsole was loaded or when the targets were actually created.  All this
    effectively enables us to get rid of custom ioctls.

(3) Ultra-paranoid configfs attribute show() and store() operations, with
    sanity and input range checking, using only safe string primitives, and
    compliant with the recommendations in Documentation/filesystems/sysfs.txt.

(4) A new function netpoll_print_options() is created in the netpoll API,
    that just prints out the configured parameters for a netpoll structure.
    netpoll_parse_options() is modified to use that and it is also exported to
    be used from netconsole.

Signed-off-by: Satyam Sharma 
Acked-by: Keiichi Kii 
Signed-off-by: Andrew Morton 
Signed-off-by: David S. Miller

[NET]: Make NAPI polling independent of struct net_device objects.

2007-10-10T23:47:45+00:00

Several devices have multiple independant RX queues per net
device, and some have a single interrupt doorbell for several
queues.

In either case, it's easier to support layouts like that if the
structure representing the poll is independant from the net
device itself.

The signature of the ->poll() call back goes from:

	int foo_poll(struct net_device *dev, int *budget)

to

	int foo_poll(struct napi_struct *napi, int budget)

The caller is returned the number of RX packets processed (or
the number of "NAPI credits" consumed if you want to get
abstract).  The callee no longer messes around bumping
dev->quota, *budget, etc. because that is all handled in the
caller upon return.

The napi_struct is to be embedded in the device driver private data
structures.

Furthermore, it is the driver's responsibility to disable all NAPI
instances in it's ->stop() device close handler.  Since the
napi_struct is privatized into the driver's private data structures,
only the driver knows how to get at all of the napi_struct instances
it may have per-device.

With lots of help and suggestions from Rusty Russell, Roland Dreier,
Michael Chan, Jeff Garzik, and Jamal Hadi Salim.

Bug fixes from Thomas Graf, Roland Dreier, Peter Zijlstra,
Joseph Fannin, Scott Wood, Hans J. Koch, and Michael Chan.

[ Ported to current tree and all drivers converted.  Integrated
  Stephen's follow-on kerneldoc additions, and restored poll_list
  handling to the old style to fix mutual exclusion issues.  -DaveM ]

Signed-off-by: Stephen Hemminger 
Signed-off-by: David S. Miller

WorkQueue: Fix up arch-specific work items where possible

2006-12-05T19:36:26+00:00

Fix up arch-specific work items where possible to use the new work_struct and
delayed_work structs.

Three places that enqueue bits of their stack and then return have been marked
with #error as this is not permitted.

Signed-Off-By: David Howells

netpoll header cleanup

2006-12-03T05:22:38+00:00

As Steve left netpoll beast, hopefully not to return soon.
He noticed that the header was messy. He straightened it
up and polished it a little, then waved goodbye.

Signed-off-by: Stephen Hemminger

netpoll queue cleanup

2006-12-03T05:22:37+00:00

The beast had a long and not very happy history. At one
point, a friend (netdump) had asked that he open up a little.
Well, the friend was long gone now, and the beast had
this dangling piece hanging (netpoll_queue).

It wasn't hard to stitch the netpoll_queue back in
where it belonged and make everything tidy.

Signed-off-by: Stephen Hemminger

netpoll retry cleanup

2006-12-03T05:22:36+00:00

The netpoll beast was still not happy. If the beast got
clogged pipes, it tended to stare blankly off in space
for a long time.

The problem couldn't be completely fixed because the
beast talked with irq's disabled. But it could be made
less painful and shorter.

Signed-off-by: Stephen Hemminger

netpoll per device txq

2006-12-03T05:22:33+00:00

When the netpoll beast got really busy, it tended to clog
things, so it stored them for later. But the beast was putting
all it's skb's in one basket. This was bad because maybe some
pipes were clogged and others were not.

Signed-off-by: Stephen Hemminger