- Copy stable/10 (r259064) to releng/10.0 as part of the
10.0-RELEASE cycle.
- Update __FreeBSD_version [1]
- Set branch name to -RC1

[1] 10.0-CURRENT __FreeBSD_version value ended at '55', so
start releng/10.0 at '100' so the branch is started with
a value ending in zero.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Disable interrupts in filter in order to avoid interrupt storm and
CPU starvation

Mechanically substitute flags from historic mbuf allocator with
malloc(9) flags in sys/dev.

- Do not reinitialize the card if it is already running.
This fixes bootp on if_smc, as bootp code perform SIOCSIFADDR
ioctl call immediately after sending the request (which causes
if_init being called) which causes the adapter to drop all the
packets received in the meantime.

- Import the common MII bitbang'ing code from NetBSD and convert drivers to
take advantage of it instead of duplicating it. This reduces the size of
the i386 GENERIC kernel by about 4k. The only potential in-tree user left
unconverted is xe(4), which generally should be changed to use miibus(4)
instead of implementing PHY handling on its own, as otherwise it makes not
much sense to add a dependency on miibus(4)/mii_bitbang(4) to xe(4) just
for the MII bitbang'ing code. The common MII bitbang'ing code also is
useful in the embedded space for using GPIO pins to implement MII access.
- Based on lessons learnt with dc(4) (see r185750), add bus barriers to the
MII bitbang read and write functions of the other drivers converted in
order to ensure the intended ordering. Given that register access via an
index register as well as register bank/window switching is subject to the
same problem, also add bus barriers to the respective functions of smc(4),
tl(4) and xl(4).
- Sprinkle some const.

Thanks to the following testers:
Andrew Bliznak (nge(4)), nwhitehorn@ (bm(4)), yongari@ (sis(4) and ste(4))
Thanks to Hans-Joerg Sirtl for supplying hardware to test stge(4).

Reviewed by: yongari (subset of drivers)
Obtained from: NetBSD (partially)

- Fix NULL pointer dereference when a packet of uneven size is being
transmitted.

Approved by: re (kib)
MFC after: 3 days

Converted the remainder of the NIC drivers to use the mii_attach()
introduced in r213878 instead of mii_phy_probe(). Unlike r213893 these
are only straight forward conversions though.

Reviewed by: yongari

Add new tunable 'net.link.ifqmaxlen' to set default send interface
queue length. The default value for this parameter is 50, which is
quite low for many of today's uses and the only way to modify this
parameter right now is to edit if_var.h file. Also add read-only
sysctl with the same name, so that it's possible to retrieve the
current value.

MFC after: 1 month

strict kobj signatures: fix assortment of miibus_writereg impls

return type should be int, not void

Reviewed by: imp, current@
Approved by: jhb (mentor)

When user_frac in the polling subsystem is low it is going to busy the
CPU for too long period than necessary. Additively, interfaces are kept
polled (in the tick) even if no more packets are available.
In order to avoid such situations a new generic mechanism can be
implemented in proactive way, keeping track of the time spent on any
packet and fragmenting the time for any tick, stopping the processing
as soon as possible.

In order to implement such mechanism, the polling handler needs to
change, returning the number of packets processed.
While the intended logic is not part of this patch, the polling KPI is
broken by this commit, adding an int return value and the new flag
IFCAP_POLLING_NOCOUNT (which will signal that the return value is
meaningless for the installed handler and checking should be skipped).

Bump __FreeBSD_version in order to signal such situation.

Reviewed by: emaste
Sponsored by: Sandvine Incorporated

- Move ether_ifdetach earlier.
- Drain callouts after ether_ifdetach.

Suggested by: jhb

Use callout_init_mtx to simplify locking somewhat. While we're here, rearrange
some operations in smc_detach to remove the need for the smc_shutdown variable.

Suggested by: jhb

Make sure we drain our taskqueues and stop our callouts in detach.

Switch to using a normal mutex instead of a spin mutex.

We still use the interrupt filter due to performance problems that show up if
we don't. The main problem seen is that, due to the interrupt being edge
triggered, we occasionally miss interrupts which leads us to not notice that
we can transmit more packets. Using the new approach, which just schedules
a task on a taskqueue, we are guaranteed to have the task run even if the
interrupt arrived while we were already executing. If we were to use an
ithread the system would mask the interrupt while the handler is run and we'd
miss interrupts.

Convert bus_space_{read,write}_* calls to bus_{read,write}_* calls.

Suggested by: jhb

This is a rewritten driver for the SMSC LAN91C111. It's based in part on the
sn(4) driver and also looking at newer drivers. The reason for the rewrite is
to support MII and to try and resolve some performance issues found when trying
to use the sn(4) driver on the Gumstix network boards.

For reference, the SMSC LAN91C111 is a non-PCI ethernet part whose lineage
dates back to Ye Olde Days of ISA. It seems to get some use in the embedded
space these days on parts lacking on-board MACs or on-board PCI controllers,
such as the XScale PXA line of ARM CPUs.

This also includes a driver for the SMSC LAN83C183 10/100 PHY.

Man page to follow.