Copy stable/9 to releng/9.3 as part of the 9.3-RELEASE cycle.

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

MFC: sync the version of netmap with the one in HEAD, including device
drivers (mostly simplifying the code in the interrupt handlers).

On passing, also merge r250414, which is related to netmap
and the use of lem/em in virtual machines.

MFC of the e1000 drivers: revisions include
227309,228281,228386,228387,228393,228405,
228415,228788,228803,229606,229767,229939,
230023,230024,230742,231796,232238,233708,
234154,234665,235256

Copy head to stable/9 as part of 9.0-RELEASE release cycle.

Approved by: re (implicit)

Change the refresh_mbuf logic slightly, add an inline
to calculate the outstanding descriptors that need to be
refreshed at any time, and use THAT in rxeof to determine
if refreshing needs to be done. Also change the local_timer
to simply fire off the appropriate interrupt rather than
schedule a tasklet, its simpler.

MFC in two weeks

Correct broken define

This delta updates the em driver to version 7.2.2 which has
been undergoing test for some weeks. This improves the RX
mbuf handling to avoid system hang due to depletion. Thanks
to all those who have been testing the code, and to Beezar
Liu for the design changes.

Next the igb driver is updated for similar RX changes, but
also to add new features support for our upcoming i350 family
of adapters.

MFC after a week

Bug fix delta to the em driver:
- Chasin down bogus watchdogs has led to an improved
design to this handling, the hang decision takes
place in the tx cleanup, with only a simple report
check in local_timer. Our tests have shown no false
watchdogs with this code.
- VLAN fixes from jhb, the shadow vfta should be per
interface, but as global it was not. Thanks John.
- Bug fixes in the support for new PCH2 hardware.
- Thanks for all the help and feedback on the driver,
changes to lem with be coming shortly as well.

Update code from Intel:
- Sync shared code with Intel internal
- New client chipset support added
- em driver - fixes to 82574, limit queues to 1 but use MSIX
- em driver - large changes in TX checksum offload and tso
code, thanks to yongari.
- some small changes for watchdog issues.
- igb driver - local timer watchdog code was missing locking
this and a couple other watchdog related fixes.
- bug in rx discard found by Andrew Boyer, check for null pointer

MFC: a week

Tighten up the rx mbuf refresh code, there were some
discrepencies from the igb version which was the target.

Change the message when neither MSI or MSIX are enabled
and a fallback to Legacy interrupts happen, the existing
message was confusing.

Do not allocate multicast array memory in multicast filter
configuration function. For failed memory allocations, em(4)/lem(4)
called panic(9) which is not acceptable on production box.
igb(4)/ixgb(4)/ix(4) allocated the required memory in stack which
consumed 768 bytes of stack memory which looks too big.

To address these issues, allocate multicast array memory in device
attach time and make multicast configuration success under any
conditions. This change also removes the excessive use of memory in
stack.

Reviewed by: jfv

A few more changes from yongari:
- code flow in handler could let interrupt be
reenabled when not wanted.
- change where the RX lock is taken to improve
performance.
- adapter->msix is true for MSI systems also,
it needs to explicitly test for 82574, good one :)

Incorporate suggested improvements from yongari.

Also, from feedback, make the multiqueue code an
option (EM_MULTIQUEUE) that is off by default.
Problems have been seen with UDP when its on.

Hook the identification LEDs of igb(4), lem(4) and em(4) devices up with
led(4) so they can be lit or f.e. made blink via `echo f2 > /dev/led/em0`
for localization purposes.

Approved by: jfv
MFC afer: 1 week (after r205869)

Fix lint build problem.

Update to igb and em:

em revision 7.0.0:
- Using driver devclass, seperate legacy (pre-pcie) code
into a seperate source file. This will at least help
protect against regression issues. It compiles along
with em, and is transparent to end use, devices in each
appear to be 'emX'. When using em in a modular form this
also allows the legacy stuff to be defined out.
- Add tx and rx rings as in igb, in the 82574 this becomes
actual multiqueue for the first time (2 queues) while in
other PCIE adapters its just make code cleaner.
- Add RX mbuf handling logic that matches igb, this will
eliminate packet drops due to temporary mbuf shortage.

igb revision 1.9.3:
- Following the ixgbe code, use a new approach in what
was called 'get_buf', the routine now has been made
independent of rxeof, it now does the update to the
engine TDT register, this design allows temporary
mbuf resources to become non-critical, not requiring
a packet to be discarded, instead it just returns and
does not increment the tail pointer.
- With the above change it was also unnecessary to keep
'spare' maps around, since we do not have the discard
issue.
- Performance tweaks and improvements to the code also.

MFC in a week

Two more build problems, missing includes and semicolon.

Opps, completely wrong version of if_em.h got into
the checkin, sorry all :(

Update the 1G drivers, shared code sync with Intel,
igb now has a queue notion that has a single interrupt
with an RX/TX pair, this will reduce the total interrupts
seen on a system. Both em and igb have a new watchdog
method. igb has fixes from Pyun Yong-Hyeon that have
improved stability, thank you :)

I wish to MFC this for 7.3 asap, please test if able.

Resync with Intel versions of both the em and igb
drivers. These add new hardware support, most importantly
the pch (i5 chipset) in the em driver. Also, both drivers
now have the simplified (and I hope improved) watchdog
code. The igb driver uses the new RX cleanup that I
first implemented in ixgbe.

em - version 6.9.24
igb - version 1.8.4

Updates for both the em and igb drivers, add support
for multiqueue tx, shared code updates, new device
support, and some bug fixes.

collapse the two em_start_locked routines in to one

- define em_transmit and em_qflush
- make buF_ring usage conditional but enabled by default

Reviewed by: jfv

This delta is primarily a fix for es2lan devices that
will sometimes fail to initialize problem due to a lock
contention with management hardware. However, in order to
deliver that fix it was necessary to take a shared code
update as a whole, and this required scattered changes in
the core code to be compatible.

The em driver now has VLAN HW support added as the igb
driver had previously.

MFC after: ASAP - in time for 7.1 RELEASE

Merge of the source for igb and em into dev/e1000, this
proved to be necessary to make the static drivers work
in EITHER/OR or BOTH configurations. Modules will still
build in sys/modules/igb or em as before.

This also updates the igb driver for support for the 82576
adapter, adds shared code fixes, and etc....

MFC after: ASAP

This delta has a few important items:

PR 122839 is fixed in both em and in igb

Second, the issue on building modules since the static kernel
build changes is now resolved. I was not able to get the fancier
directory hierarchy working, but this works, both em and igb
build as modules now.

Third, there is now support in em for two new NICs, Hartwell
(or 82574) is a low cost PCIE dual port adapter that has MSIX,
for this release it uses 3 vectors only, RX, TX, and LINK. In
the next release I will add a second TX and RX queue. Also, there
is support here for ICH10, the followon to ICH9. Both of these are
early releases, general availability will follow soon.

Fourth: On Hartwell and ICH10 we now have IEEE 1588 PTP support,
I have implemented this in a provisional way so that early adopters
may try and comment on the functionality. The IOCTL structure may
change. This feature is off by default, you need to edit the Makefile
and add the EM_TIMESYNC define to get the code.

Enjoy all!!

This update primarily addresses the ability to have both the em
and the igb driver static in the kernel. But it also reflects
some other bug fixes in my development stream at Intel.
PR 122373 is also fixed in this code.

Need to add define of FAST interrupts as default

This change introduces a split to the Intel E1000 driver, now rather than
just em, there is an igb driver (this follows behavior with our Linux drivers).
All adapters up to the 82575 are supported in em, and new client/desktop support
will continue to be in that adapter.

The igb driver is for new server NICs like the 82575 and its followons.
Advanced features for virtualization and performance will be in this driver.

Also, both drivers now have shared code that is up to the latest we have
released. Some stylistic changes as well.

Enjoy :)

A minor issue with lock names, WITNESS complains
when the two locks are the same...

One nit, FAST handling is now in #ifdef's for compatibility
between RELEASES, but we want it on by default in 7 and later,
add that define, and take out a fragment left from a workaround
being removed.

Driver version 6.7.3
- Bring HEAD up to the latest shared code
- Fix TSO problem using limited MSS and forwarding
- Dual lock implementation
- New device support
- For my ease, this code can compile in either 6.x or later
- brings this driver in sync with the 6.3

A number of small fixes:
- duplicate #define in header, thanks to Kevin Lo for pointing out.
- incorrect BUSMASTER enable logic, thanks Patrick Oeschger
- 82543 fails due to bogus IO BAR logic
- Allow 82571 to use MSI interrupts
- Checksum Offload for UDP not working on 82575

Approved by:re

Couple of changes, back down on last TSO change, instead make old
adapter list still capable, but only PCI-E adapters are now enabled.
The user can enable older PCI-X or PCI adapters using ifconfig.
Secondly, Arthur Hartwig pointed out my MSI change was not working
correctly, changed to something that now does. Thanks Arthur.
There was also a fundamental bug in the 82575 MSIX code, the MSIX
registers had to be mapped, opps :)

Rubber-stamped by: Pdeuskar

This delta adds two bug fixes: one that makes HW Offload logic in
legacy codepath match the 82575, without this we were seeing bridging
fail on 82546 adapters. Secondly, I have limited TSO to PCI Express
adapters, I meant to do this and it got dropped in the earlier delta.
Next, I am dropping in the latest shared code from our development
team, consensus was that this should be done frequently, so I am :)

Approved by: pdeuskar

$FreeBSD$ tags are not compilable C code; wrap in either __FBSDID() or
in comments for .c and .h files respectively. Jack may want to clean up
style or other aspects once he's up and about again, but this gets the
kernel compiling.

Merge in the new driver (6.5.0) of Intel. This has a new
shared code infrastructure that is family specific and
modular. There is also support for our latest gigabit
nic, the 82575 that is MSI/X and multiqueue capable.

The new shared code changes some interfaces to the core
code but testing at Intel has been going on for months,
it is fairly stable.

I have attempted to be careful in retaining any fixes that
CURRENT had and we did not, I apologize in advance if any
thing gets clobbered, I'm sure I'll hear about it :)

Approved by pdeuskar

Move magic PCIe workaround constant to header - add appropriate comment

Suggested by: jfvogel

Add MSI support to em(4), bce(4), and mpt(4). For now, we only support
devices that support a maximum of 1 message, and we use that 1 message
instead of the INTx rid 0 IRQ with the same interrupt handler, etc.

Instead of using the legacy if_timer/if_watchdog interface create
our own watchdog that piggybacks on the em_local_timer() routine.

We suppose that the if_timer/if_watchdog interface should be
obsoleted, since it doesn't fit the modern SMP network stack.
NIC drivers should create their own watchdogs, that check and
clear the timers always holding driver's lock.

In collaboration with: jfv, scottl

Rework the transmit register handling. In em_encap() store index of
the EOP descriptor in the first descriptor of the packet. And then
in em_txeof() search for DD bits set only in the EOP descriptors,
embedding the cleanup of all packet's descriptors into inner loop.

This change is important for future chips, where DD bit is going
to be set only on the EOP descriptors.

Submitted by: jfv

Merge new vendor release - 6.2.9.

Details:
o if_em.c changes:
- Added several new PCI ids.
- Check em_check_phy_reset_block() before doing SIOCSIFMEDIA ioctl.
- Don't touch TARC registers, they are now handled in shared
code in if_em_hw.c.
- Move RDH and RDT setting to the end of
em_initialize_receive_unit().
- Declare em_read_pcie_cap_reg(), now empty.
o if_em_hw.c dropped in from vendor, then restored rev. 1.15.
o if_em_hw.h dropped in from vendor, then modified:
- Added RX overrun interrupt flag to interrupt enable mask.
- Remove declarations of em_io_read(), em_io_write().

Approved by: jfv

Backout bogus checkin to HEAD
Approved by: scottl

This is the merge of the Intel 6.2.9 driver. It provides all new shared code,
new device support, and it is hoped a more stable driver for 6.2. RELEASE.
This checkin was discussed and approved today by RE, scottl, jhb, and pdeuskar

Add support for TSO. Thanks to Andre for adding support in the stack
and Jack Vogel for driver changes.

Submitted by: Jack Vogel

Just foward declare 'struct adapter' instead of declaring an actual
'adapter' structure.

Overhaul Rx path to recover from mbuf cluster allocation failure.
o Create one more spare DMA map for Rx handler to recover from
bus_dmamap_load_mbuf_sg(9) failure.
o Make sure to update status bit in Rx descriptors even if we failed
to allocate a new buffer. Previously it resulted in stuck condition
and em_handle_rxtx task took up all available CPU cycles.
o Don't blindly unload DMA map. Reuse loaded DMA map if received
packet has errors. This would speed up Rx processing a bit under
heavy load as it does not need to reload DMA map in case of error.
(bus_dmamap_load_mbuf_sg(9) is the most expensive call in driver
context.)
o Update if_iqdrops counter if it can't allocate a mbuf cluster.
With this change it's now possible to see queue dropped packets
with netstat(1).
o Update mbuf_cluster_failed counter if fixup code failed to
allocate mbuf header.
o Return ENOBUFS instead of ENOMEM in case of Rx fixup failure.
o Make adapter->lmp NULL in case of Rx fixup failure. Strictly
specking it's not necessary for correct operation but it makes
the intention clear.
o Remove now unused dropped_pkts member in softc.

With these changes em(4) should survive mbuf cluster allocation
failure on Rx path.

Reviewed by: pdeuskar, glebius (with improvements)

Revert back changes to made in rev 1.109 of if_em.c which were unnecessary.
This makes it easier for us to get the changes into -current and to -stable quickly.

Merge in new driver from Intel, version 6.0.5. It adds support for
80003 NICs and NICs found on ICH8 mobos, and improves support for
already known chips.

Details:
- if_em.c. Merged manually, viewing diff between new vendor
driver and previous one. This was an easy task, because
most changes between 5.1.5 and 6.0.5 are bugfixes taken
from FreeBSD.
- if_em_hw.h. Dropped in from vendor, and then restored
revisions 1.16, 1.17, 1.18.
- if_em_hw.c. Dropped in from vendor, and then restored
revision 1.15.
- if_em_osdep.h. Added new required macros from vendor file
and add a hack against define namespace mangling in
if_em_hw.h. Intel made another hack, but I prefer mine.

Since resetting hardware takes a very long time and results in link
renegotiation, we only initialize the hardware only when it is
absolutely required. Process SIOCGIFADDR ioctl in em(4) when we know
an IPv4 address is added. Handling SIOCGIFADDR in a driver is
layering violation but it seems that there is no easy way without
rewritting hardware initialization code to reduce settle time after
reset.

This should fix a long standing bug which didn't send ARP packet when
interface address is changed or an alias address is added. Another
effect of this fix is it doesn't need additional delays anymore when
adding an alias address to the interface.
While I'm here add a new if_flags into softc which remembers current
prgroammed interface flags and make use of it when we have to program
promiscuous mode.

Tested by: Atanas <atanas AT asd DOT aplus DOT net>
Analyzed by: rwatson
Discussed with: -stable

- Second style(9) megacleanup.
- Rename "adapter" to "sc"/"softc", to be like other drivers.

(-13 Kb less source code)

Move includes from if_em.h to if_em.c and sort them.

Now that the em driver no longer needs to directly touch the scheduler, remove some
unneeded headers.

Significant performance improvements for the if_em driver:

- Only update the rx ring consumer pointer after running through the rx loop,
not with each iteration through the loop.
- If possible, use a fast interupt handler instead of an ithread handler. Use
the interrupt handler to check and squelch the interrupt, then schedule a
taskqueue to do the actual work. This has three benefits:
- Eliminates the 'interrupt aliasing' problem found in many chipsets by
allowing the driver to mask the interrupt in the NIC instead of the
OS masking the interrupt in the APIC.
- Allows the driver to control the amount of work done in the interrupt
handler. This results in what I call 'adaptive polling', where you get
the latency benefits of a quick response to interrupts with the
interrupt mitigation and work partitioning of polling. Polling is still
an option in the driver, but I consider it orthogonal to this work.
- Don't hold the driver lock in the RX handler. The handler and all data
associated is effectively serialized already. This eliminates the cost of
dropping and reaquiring the lock for every receieved packet. The result
is much lower contention for the driver lock, resulting in lower CPU usage
and lower latency for interactive workloads.

The amount of work done in the taskqueue is controlled by the sysctl
dev.em.N.rx_processing_limit

and tunable
hw.em.rx_process_limit

Setting these to -1 effectively removes the limit.

The fast interrupt and taskqueue can be disabled by defining NO_EM_FASTINTR.
This work has been shown to increase fast-forwarding from ~570 kpps to
~750 kpps (note that the same NIC hardware seems unable to transmit more than
800 kpps, so this increase appears to be limited almost solely by the
hardware). Gains have been shown in other workloads, ranging from better
performance to elimination of over-saturation livelocks.

Thanks to Andre Opperman for his time and resources from his network
performance project in performing much of the testing. Thanks to Gleb
Smirnoff and Danny Braniss for their help in testing also.

busdma cleanup for em(4).
- don't force busdma to pre-allocate bounce pages for parent tag.
- use system supplied roundup2 macro instead of rolling its own version.
- TX/RX decriptor length should be multiple of 128. There is no
no need to expand the size with the multiple of 4096.
- don't create/destroy DMA maps in TX/RX handlers. Use pre-allocated
DMA maps. Since creating DMA maps on sparc64 is time consuming
operations(resource mananger overhead), this change should boost
performance on sparc64. I could get > 2x speedup on Ultra60.
- TX/RX descriptors could be aligned on 128 boundary. Aligning them
on PAGE_SIZE is waste of resource.
- don't blindly create TX DMA tag with size of MCLBYTES * 8. The size
is only valid under jumbo frame environments. Instead of using the
hardcoded value, re-compute necessary size on the fly.
- RX side bus_dmamap_load_mbuf_sg(9) support.
- remove unused macro EM_ROUNDUP and constant EM_MMBA.

Reviewed by: scottl
Tested by: glebius

- Backout last change, since it is memory overkill for a non busy host or
for a notebook with em(4) adapter.
- Introduce tunables em.hw.txd and em.hw.rxd, which allow administrator
to configure number of transmit and receive descriptors.
- Check em.hw.txd and em.hw.rxd against hardware limits [*] and require
them to be multiple of 128.

[*] According to comments in if_em.h the 82540EM/82541ER chips can handle
more than 256 descriptors. Since we don't have this hardware to test,
we decided to mimic NetBSD wm(4) driver, that limits these chips to
256 descriptors.

In collaboration with: yongari

Give a try to autoconfiguring the number of transmit and receive
descriptors depending on chip revision.

- Introduce two more stat counters, counting number of RX
overruns and number of watchdog timeouts.
- Do not log(9) RX overrun events, since this pessimizes
things under load [1].
- Do not increase if->if_oerrors in em_watchdog(), since
this leads to counter slipping back, when if->if_oerrors
is recalculated in em_update_stats_counters(). Instead
increase watchdog counter in em_watchdog() and take it
into account in em_update_stats_counters().

Submitted by: ade [1]

Make em(4) work on big-endian architectures.
- disable jumbo frame support on strict alignment architectures due
to the limitation of hardware. The driver needs a fix-up code for
RX side. The fix will show up in near future.
- fix endian issue for 82544 on PCI-X bus. I couldn't test this as
I don't have the NIC/hardware.
- prefer PCIR_BAR to hardcoded EM_MMBA.
- Properly checks for for 64bit BAR [1]
- replace inl/outl with bus_space(9) [1]
- fix endian issue on VLAN handling.
- reorder header files and remove unnecessary one.

Reviewed by: cognet
No response from: pdeuskar, tackerman
Obtained from: OpenBSD [1]

Some more minor cleanups of em(4) driver:
- Destroy mutex in case of attach failure. [1]
- Lock properly em_watchdog(). [1]
- Lock properly em_sysctl_int_delay(). [1]
- Remove unused global adapter linked list.
- Remove unused dma_size field from struct em_dma_alloc.
- Do not touch interface statistics, that must be edited
only by upper layers. [1]

Submitted by: yongari [1]

Revamp interrupt handling in em(4) driver:

o Do not mask the RX overrun interrupt.

o Rewrite em_intr():
- Axe EM_MAX_INTR.
- Cycle acknowledging interrupts and processing
packets until zero interrupt cause register is
read.
- If RX overrun comes in log this fact. [ NetBSD also
resets adapter in this case, but my tests showed that
this is not needed and only pessimizes behavior under
heavy load. ]
- Since almost all functions is rewritten, style the
remaining lines.

This fixes em(4) interfaces wedging under high load.

In collaboration with: wpaul, cognet
Obtained from: NetBSD

Remove bridge(4) from the tree. if_bridge(4) is a full functional
replacement and has additional features which make it superior.

Discussed on: -arch
Reviewed by: thompsa
X-MFC-after: never (RELENG_6 as transition period)

Stop embedding struct ifnet at the top of driver softcs. Instead the
struct ifnet or the layer 2 common structure it was embedded in have
been replaced with a struct ifnet pointer to be filled by a call to the
new function, if_alloc(). The layer 2 common structure is also allocated
via if_alloc() based on the interface type. It is hung off the new
struct ifnet member, if_l2com.

This change removes the size of these structures from the kernel ABI and
will allow us to better manage them as interfaces come and go.

Other changes of note:
- Struct arpcom is no longer referenced in normal interface code.
Instead the Ethernet address is accessed via the IFP2ENADDR() macro.
To enforce this ac_enaddr has been renamed to _ac_enaddr.
- The second argument to ether_ifattach is now always the mac address
from driver private storage rather than sometimes being ac_enaddr.

Reviewed by: sobomax, sam

Changes to update driver with latest Intel driver version 2.1.7
- Changed from using explicit devices id to using descriptive labels.
- Added support for 82573 and 82546 Quad adapters.
- Corrected support for 82547EI and 82541ER (mac_type was not assigned)
- Removed #ifdef DBG_STATS and extraneous code.

if_em_hw.c/if_em_hw.h
- Added support for 82573 and 82546 Quad adapters.
- Brought forward Intel's most current mac and phy changes.

Convert if_em to the new bus_dmamap_load_sg() interface. The old callback
was really just a waste of cycles, so this streamlines it considerably.

Correct a bug in the if_em driver relating to the use of vlans with
promiscuous mode introduced in 1.45, which programs the em card not
to strip or prepend tags when in promiscuous mode without also
modifying behavior to manually prepend a vlan header in the event
that the card isn't doing it on transmit. Due to a feature of card
operation, if the global VLAN prepend/strip register isn't set,
setting the VLAN tag flag on individual packet descriptors will
cause the packet to be transmitted using ISL encapsulation rather
than 802.1Q VLAN encapsulation.

This fix causes em_encap() to prepend the header by tracking whether
the card is configured to temporarily disable prepending/stripping
due to promiscuous mode. As a result, entering promiscuous mode on
the parent em interface no longer causes vlans to appear to "wedge"
or transmit ISL-encapsulated frames, which typically will not be
configured/spoken by the other endpoints on the VLAN trunk. This
bug may also exist in other drivers, and the additional vlan
encapsulation logic should be abstracted and centralized in
if_vlan.c if so.

RELENG_5_3 candidate.

MFC after: 1 week
Tested by: pjd, rwatson
Reported by: astesin at ukrtelecom dot net
Reported by: Mike Tancsa <mike at sentex dot net>
Reported by: Iasen Kostov <tbyte at OTEL dot net>

Unbreak the build.

Pointy hat to: bms

Remove now-unused sysctl members.

Added support for Intel PRO/1000 GT Desktop Adapter(Device ID 8086 107C)
Removed support for Intel 82541ER
Added fix for 82547 which corrects an issue with Jumbo frames larger than 10k.
Added fix for vlan tagged frames not being properly bridged.
Corrected TBI workaround.
Corrected incorrect LED operation issues

Submitted by: tackerman (Tony Ackerman)
MFC after: 2 weeks

Add missing <sys/module.h> includes

- Code cleanup
- In the receive routine handle the case where last descriptor could have
less than 4 bytes of data.
- Handle race between detach/ioctl routine.

MFC after: 3 days

locking fixups:

o correct recursive locking when polling and in em_82547_move_tail
o destroy mutex on detach
o add EM_LOCK_ASSERT and similar macros for creating+deleteing the mtx

Submitted by: Daniel Eischen <eischen@vigrid.com>

add locking

Reviewed by: Prafulla Deuskar <pdeuskar@FreeBSD.ORG>
Sponsored by: FreeBSD Foundation

Add support for new devices.
Bug Fixes:
- Allow users to use LAA
- Remember promiscuous mode settings while bridging
- Allow gratuitous arp's to be sent

PR: 52966/54488
MFC after: 1 week

Prefer new location of pci include files (which have only been in the
tree for two or more years now), except in a few places where there's
code to be compatible with older versions of FreeBSD.

Add facilities for tuning the "em" driver's interrupt delays without
recompiling the driver. See the comments near the top of "if_em.h"
for descriptions of these delays. Four new loader tunables control
the system-wide default values:

hw.em.tx_int_delay
hw.em.rx_int_delay
hw.em.tx_abs_int_delay
hw.em.rx_abs_int_delay

The tunables are specified in microseconds. The valid range is
0-67108 usec., and 0 means that the timer is disabled.

There are also four new sysctls (actually, a set of four for each
"em" device in the system) to query and change the interrupt delays
after the system is up:

hw.em0.tx_int_delay
hw.em0.rx_int_delay
hw.em0.tx_abs_int_delay (not present for 82542/3/4 adapters)
hw.em0.rx_abs_int_delay (not present for 82542/3/4 adapters)

It seems to be OK to change these values even while the adapter is
passing traffic.

Approved by: Prafulla Deuskar <pdeuskar@FreeBSD.ORG>
MFC after: 4 weeks

Correct comments to indicate that the EM_RADV and EM_TADV parameters
are not applicable to the 82544.

The em(4) driver has been converted to busdma and doesn't use
vtophys() anymore, so remove the alpha hack which defines
vtophys() to alpha_XXX_dmamap().

Add support for Quad port adapter
Add sysctl's to display statistics/debug_info
Set WAIT_FOR_AUTONEG_DEFAULT to zero by default
Increment packet in/out statistics inline instead of every two seconds.

MFC after: 3 days

- Fix breakage on PAE enabled kernel
- Don't use vtophys when you can get physical address using bus_dma API

Submitted by: jake (Jake Burkholder)

- Bus DMA'fy the driver
- Use htole* macros where appropriate so that the driver could work on non-x86 architectures
- Use m_getcl() instead of MGETHDR/MCLGET macros
Submitted by: sam (Sam Leffler)

Added support for 82541 and 82547 based adapters.
- These have Intel gigabit PHY
- 82547 uses CSA interface

MFC after: 1 week

- Move to array based indexing for TX/RX descriptor/buffer management
- Added support for ITR (interrupt throttle register). This feature is available on
adapters based on 82545 and above
- Fixed problem with vlan support when traffic has priority bits set. (kern/45907)

PR: kern/45907
MFC after: 1 week

network interface driver changes:

o don't strip the Ethernet header from inbound packets; pass packets
up the stack intact (required significant changes to some drivers)
o reference common definitions in net/ethernet.h (e.g. ETHER_ALIGN)
o track ether_ifattach/ether_ifdetach API changes
o track bpf changes (use BPF_TAP and BPF_MTAP)
o track vlan changes (ifnet capabilities, revised processing scheme, etc.)
o use if_input to pass packets "up"
o call ether_ioctl for default handling of ioctls

Reviewed by: many
Approved by: re

- Set RS (Report Status) bit on all descriptors of a packet instead of just the last one.
- Set RDTR to zero by default instead of 28.
- Fixed a problem with TX hangs with jumbo frames when number of fragments in the mbuf chain
is large.
- Added support for 82540EP based cards.

MFC after: 3 days

Corrected license in the source files. It should say "MUST" instead of "MAY".

MFC after: 2 days

Back out TX/RX descriptor/buffer management changes from earier commit.
We are having panics with the driver under stress with jumbo frames.
Unfortunately we didnot catch it during our regular test cycle.
I am going to MFC the backout immediately.

TX/RX descriptor/buffer management changes.
Use array based scheme instead of queueing macros.

Submitted by: Luigi Rizzo (rizzo@icir.org)
MFC after: 3 days

- Use IO mode to reset the controller (82544 and beyond)
- Read the Mac address only once during attach.
(This fixes the failover issue observed using the bonding driver)

MFC after: 3 days

Added support for 82545EM and 82546EB based adapters.
Added Vlan support.

MFC after: 1 week

Added support for 82540EM based cards.
Cosmetic changes to make code more unix-like.

MFC after: 1 week

- Added support for receive in multiple
descriptors. This simplifies code for jumbo frames.
- Cleaned up coding conventions to make code more unix-like.
- Cleaned up code in if_em_fxhw.c and if_em_phy.c.
Added relevant comments.

MFC after: 1 week

-Remove unneeded include stddef.h
-Modify modules Makefile so that em driver compiles only on
i386 platform. (Alpha not supported yet)

PR: kern/32993
MFC after: 1

This is the first commit of the Intel gigabit driver for
PRO/1000 cards.

Submitted by:Prafulla Deuskar
Reviewed by: Paul Saab
MFC after:1 week