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

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

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

Approved by: re (implicit)

According to the OpenSolaris source the PCI latency and the cache line size
should be set for Sun ERI.
Tested by: yongari

- Initialize the ifnet structure, especially if_dname, before probing
the PHYs as some PHY drivers use it (but probably shouldn't). How
gem(4) has worked with brgphy(4) on powerpc without this so far is
unclear to me.
- Introduce a dying flag which is set during detach and checked in
gem_ioctl() in order to prevent active BPF listeners to clear
promiscuous mode which may lead to the tick callout being restarted
which will trigger a panic once it's actually gone.
- In gem_stop() reset rather than just disable the transmitter and
receiver in order to ensure we're not unloading DMA maps still in
use by the hardware. [1]
- The blanking time is specified in PCI clocks so we should use twice
the value when operating at 66MHz.
- Spell some 2 as ETHER_ALIGN and a 19 as GEM_STATUS_TX_COMPLETION_SHFT
to make the actual intentions clear.
- As we don't unload the peak attempts counter ignore its overflow
interrupts.
- Remove a stale setting of a variable to GEM_TD_INTERRUPT_ME which
isn't used afterwards.
- For optimum performance increment the TX kick register in multiples
of 4 if possible as suggested by the documentation.
- Partially revert r164931; drivers should only clear the watchdog
timer if all outstanding TX descriptors are done.
- Fix some debugging strings.
- Add a missing BUS_DMASYNC_POSTWRITE in gem_rint().
- As the error paths in the interrupt handler are generally unlikely
predict them as false.
- Add support for the SBus version of the GEM controller. [2]
- Add some lock assertions.
- Improve some comments.
- Fix some more or less cosmetic issues in the code of the PCI front-end.
- Change some softc members to be unsigned where more appropriate and
remove unused ones.

Approved by: re (kib)
Obtained from: NetBSD (partially) [2], OpenBSD [1]
MFC after: 2 weeks

Split the registers into two halves in preparation for SBus support.

Obtained from: NetBSD (loosely)
MFC after: 2 weeks

o In preparation for basing a new driver on this one:
- ANSIfy
- try to bring closer to style(9)
- remove banal comments.
o Add my copyright for having done lots of fixes and improvements.

o Revert the part of if_gem.c rev. 1.35 which added a call to gem_stop()
to gem_attach() as the former access softc members not yet initialized
at that time and gem_reset() actually is enough to stop the chip. [1]
o Revise the use of gem_bitwait(); add bus_barrier() calls before calling
gem_bitwait() to ensure the respective bit has been written before we
starting polling on it and poll for the right bits to change, f.e. even
though we only reset RX we have to actually wait for both GEM_RESET_RX
and GEM_RESET_TX to clear. Add some additional gem_bitwait() calls in
places we've been missing them according to the GEM documentation.
Along with this some excessive DELAYs, which probably only were added
because of bugs in gem_bitwait() and its use in the first place, as
well as as have of an gem_bitwait() reimplementation in gem_reset_tx()
were removed.
o Add gem_reset_rxdma() and use it to deal with GEM_MAC_RX_OVERFLOW errors
more gracefully as unlike gem_init_locked() it resets the RX DMA engine
only, causing no link loss and the FIFOs not to be cleared. Also use it
deal with GEM_INTR_RX_TAG_ERR errors, with previously were unhandled.
This was based on information obtained from the Linux GEM and OpenSolaris
ERI drivers.
o Turn on workarounds for silicon bugs in the Apple GMAC variants.
This was based on information obtained from the Darwin GMAC and Linux GEM
drivers.
o Turn on "infinite" (i.e. maximum 31 * 64 bytes in length) DMA bursts.
This greatly improves especially RX performance.
o Optimize the RX path, this consists of:
- kicking the receiver as soon as we've a spare descriptor in gem_rint()
again instead of just once after all the ready ones have been handled;
- kicking the receiver the right way, i.e. as outlined in the GEM
documentation in batches of 4 and by pointing it to the descriptor
after the last valid one;
- calling gem_rint() before gem_tint() in gem_intr() as gem_tint() may
take quite a while;
- doubling the size of the RX ring to 256 descriptors.
Overall the RX performance of a GEM in a 1GHz Sun Fire V210 was improved
from ~100Mbit/s to ~850Mbit/s.
o In gem_add_rxbuf() don't assign the newly allocated mbuf to rxs_mbuf
before calling bus_dmamap_load_mbuf_sg(), if bus_dmamap_load_mbuf_sg()
fails we'll free the newly allocated mbuf, unable to recycle the
previous one but a NULL pointer dereference instead.
o In gem_init_locked() honor the return value of gem_meminit().
o Simplify gem_ringsize() and dont' return garbage in the default case.
Based on OpenBSD.
o Don't turn on MAC control, MIF and PCS interrupts unless GEM_DEBUG is
defined as we don't need/use these interrupts for operation.
o In gem_start_locked() sync the DMA maps of the descriptor rings before
every kick of the transmitter and not just once after enqueuing all
packets as the NIC might instantly start transmitting after we kicked
it the first time.
o Keep state of the link state and use it to enable or disable the MAC
in gem_mii_statchg() accordingly as well as to return early from
gem_start_locked() in case the link is down. [3]
o Initialize the maximum frame size to a sane value.
o In gem_mii_statchg() enable carrier extension if appropriate.
o Increment if_ierrors in case of an GEM_MAC_RX_OVERFLOW error and in
gem_eint(). [3]
o Handle IFF_ALLMULTI correctly; don't set it if we've turned promiscuous
group mode on and don't clear the flag if we've disabled promiscuous
group mode (these were mostly NOPs though). [2]
o Let gem_eint() also report GEM_INTR_PERR errors.
o Move setting sc_variant from gem_pci_probe() to gem_pci_attach() as
device probe methods are not supposed to touch the softc.
o Collapse sc_inited and sc_pci into bits for sc_flags.
o Add CTASSERTs ensuring that GEM_NRXDESC and GEM_NTXDESC are set to
legal values.
o Correctly set up for 802.3x flow control, though #ifdef out the code
that actually enables it as this needs more testing and mainly a proper
framework to support it.
o Correct and add some conversions from hard-coded functions names to
__func__ which were borked or forgotten in if_gem.c rev. 1.42.
o Use PCIR_BAR instead of a homegrown macro.
o Replace sc_enaddr[6] with sc_enaddr[ETHER_ADDR_LEN].
o In gem_pci_attach() in case attaching fails release the resources in
the opposite order they were allocated.
o Make gem_reset() static to if_gem.c as it's not needed outside that
module.
o Remove the GEM_GIGABIT flag and the associated code; GEM_GIGABIT was
never set and the associated code was in the wrong place.
o Remove sc_mif_config; it was only used to cache the contents of the
respective register within gem_attach().
o Remove the #ifdef'ed out NetBSD/OpenBSD code for establishing a suspend
hook as it will never be used on FreeBSD.
o Also probe Apple Intrepid 2 GMAC and Apple Shasta GMAC, add support for
Apple K2 GMAC. Based on OpenBSD.
o Add support for Sun GBE/P cards, or in other words actually add support
for cards based on GEM to gem(4). This mainly consists of adding support
for the TBI of these chips. Along with this the PHY selection code was
rewritten to hardcode the PHY number for certain configurations as for
example the PHY of the on-board ERI of Blade 1000 shows up twice causing
no link as the second incarnation is isolated.
These changes were ported from OpenBSD with some additional improvements
and modulo some bugs.
o Add code to if_gem_pci.c allowing to read the MAC-address from the VPD on
systems without Open Firmware.
This is an improved version of my variant of the respective code in
if_hme_pci.c
o Now that gem(4) is MI enable it for all archs.

Pointed out by: yongari [1]
Suggested by: rwatson [2], yongari [3]
Tested on: i386 (GEM), powerpc (GMACs by marcel and yongari),
sparc64 (ERI and GEM)
Reviewed by: yongari
Approved by: re (kensmith)

o Implemented Rx/Tx checksum offload. The simple checksum logic in
GEMs is unable to discriminate UDP from TCP packets such that
it can generate 0x0000 checksum value for the UDP datagram. So the
UDP checksum offload was disabled by default. You can enable it
by setting link0 flag with ifconfig(8).
o bus_dma(9) clean up. It now correctly set number of required DMA
segments/size and removed incorrect use of BUS_DMA_ALLOCNOW flag
in static allocations done via bus_dmamem_alloc(9).
o Implemented ALTQ(9) support.
o Implemented Tx side bus_dmamap_load_mbuf_sg(9) which can remove
several book keeping chores orginated from call-back mechanism.
Therefore gem_txdma_callback() was removed and its functionality
was reimplemented in gem_load_txmbuf().
o Don't set GEM_TD_START_OF_PACKET flag until all remaining mbuf
chains are set. I think it was a long standing bug and it caused
fluctuating interrupts/CPU usage patterns while netperf test
is in progress. Previously it seems that we race with the device.
Because I don't have a documentation for GEM I'm not sure this is
correct but almost all other documentations I have stated this
implications on setting SOP mark in descriptor ring(e.g. hme(4)).
o Borrowed gem_defrag() from ath(4) which is supposed to be much
faster than m_defrag(9) since it's not need to defrag all
mbuf chains.
o gem_load_txmbuf() was changed to allow passed mbuf chains to free.
Caller of gem_load_txmbuf() correctly handles freed mbuf chains.
o In gem_start_locked(), added checks for availability of Tx
descriptors before trying to load DMA maps which could save CPU
cycles when number of available descriptors are low. Also, simplyfy
IFF_DRV_OACTIVE detection logic.
o Removed hard-coded function names in CTR macros and replaced it
with __func__.
o Moved statistics counter register access to gem_tick() to reduce
number of PCI bus accesses. There is no reason to update statistics
counters in interrupt handler.
o Removed unnecessary call of gem_start_locked() in gem_ioctl().

Reviewed by: grehan (initial version), marius (with improvements and suggestions)
Tested by: grehan (ppc), marius(sparc64)

Start each of the license/copyright comments with /*-, minor shuffle of lines

Incorporate changes made to the NetBSD version of this driver.

- Remove some obsolete code (NetBSD gem.c r1.12)
- Clean up how the local MAC address is programmed (NetBSD gem.c r1.13)
- Make the driver work on PowerMacs with gigabit interfaces
(NetBSD gem.c r1.14 and r1.15, gemreg.h r1.3 and r1.4, gemvar.h r1.6 and 1.7)
- Suppress RX_MAC interrutps regarding the FRAME_COUNT register.
(NetBSD gem.c r1.16 and r1.17)
- Fix receiver lockups. (NetBSD gem.c r1.18, gemvar.h r1.8)
- Distinguish between Apple and Sun variants (NetBSD if_gem_pci.c r1.9)

Reviewed by: tmm
Obtained from: NetBSD

Add a driver for the Sun GEM (Gigabit) and ERI (100 Mb/s) PCI ethernet
adaptors, ported from NetBSD.