Copy head@r302406 to stable/11 as part of the 11.0-RELEASE cycle.
Prune svn:mergeinfo from the new branch, as nothing has been merged
here.

Additional commits post-branch will follow.

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

Fix style bug: rename the refcount field of m_ext to ext_cnt, to match
other members.

Sponsored by: Nginx, Inc.

All mbuf external free functions never fail, so let them be void.

Sponsored by: Nginx, Inc.

The r48589 promised to remove implicit inclusion of if_var.h soon. Prepare
to this event, adding if_var.h to files that do need it. Also, include
all includes that now are included due to implicit pollution via if_var.h

Sponsored by: Netflix
Sponsored by: Nginx, Inc.

Give (*ext_free) an int return value allowing for very sophisticated
external mbuf buffer management capabilities in the future.

For now only EXT_FREE_OK is defined with current legacy behavior.

Sponsored by: The FreeBSD Foundation

Add an mbuf pointer parameter to (*ext_free) to give the external
free function access to the mbuf the external memory was attached
to.

Mechanically adjust all users to include the mbuf parameter.

This fixes a long standing annoyance for external free functions.
Before one had to sacrifice one of the argument pointers for this.

Sponsored by: The FreeBSD Foundation

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

Give MEXTADD() another argument to make both void pointers to the
free function controlable, instead of passing the KVA of the buffer
storage as the first argument.

Fix all conventional users of the API to pass the KVA of the buffer
as the first argument, to make this a no-op commit.

Likely break the only non-convetional user of the API, after informing
the relevant committer.

Update the mbuf(9) manual page, which was already out of sync on
this point.

Bump __FreeBSD_version to 800016 as there is no way to tell how
many arguments a CPP macro needs any other way.

This paves the way for giving sendfile(9) a way to wait for the
passed storage to have been accessed before returning.

This does not affect the memory layout or size of mbufs.

Parental oversight by: sam and rwatson.

No MFC is anticipated.

Remove the __inline qualifier from a function which is in fact not an
inline but instead a module wide function, thus quieting a GCC 4.2 warning.

Replace m_extadd() with macro version MEXTADD().

Propagate rename of IFF_OACTIVE and IFF_RUNNING to IFF_DRV_OACTIVE and
IFF_DRV_RUNNING, as well as the move from ifnet.if_flags to
ifnet.if_drv_flags. Device drivers are now responsible for
synchronizing access to these flags, as they are in if_drv_flags. This
helps prevent races between the network stack and device driver in
maintaining the interface flags field.

Many __FreeBSD__ and __FreeBSD_version checks maintained and continued;
some less so.

Reviewed by: pjd, bz
MFC after: 7 days

Convert the atomic_ptr() operations over to operating on uintptr_t
variables rather than void * variables. This makes it easier and simpler
to get asm constraints and volatile keywords correct.

MFC after: 3 days
Tested on: i386, alpha, sparc64
Compiled on: ia64, powerpc, amd64
Kernel toolchain busted on: arm

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

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

change NULL to 0 to silence warning.

Initialize the USED flag in new external receive buffers to 0, not to 1.
We put them directly onto the free list instead of calling the
external mbuf free routine (that routine would have cleaned the flag).

This fixes a bug which manifests itself in falsely reporting a lot of used
buffers when configuring the interface down.

Explain why the lock-free allocation algorithm is safe in our case
while beeing not safe in the general case. Thanks to David Schultz
<das@freebsd.org> for help.

Reinvent the used-flag for external mbufs. This and the on-card flag
are now in the header of the external buffer itself which allows us
to manipulate them in the free routine without having to lock the softc
structure or the free list. To get space for these flags the chunk number
is reduced to 8 bit which amounts to a maximum of 256 chunks per allocated
page. This restriction is now enforced by a CTASSERT.

Remove a superfluous ) from the previous commit. This was obviously
a result of the current solar storm.

Make the maximum number of pages for external mbufs configurable in
the kernel environment and accessible as a RO sysctl.

Explain that the HE155 will not work in 64-bit/66MHz slots, but may work
in 64-bit/33MHz slots.

Inline a function that was called only in one place directly into that place.

Correct a bug when the number of pages for external mbufs was
very large. In this case the page number could overflow into the large
buffer flag. Make this more unlikley by move that flag further away.

We have some space in the external mbufs so use this space for
the external buffer reference count. This saves us a malloc() + free()
per small receive mbuf.

Defer allocation of the actual receive mbuf until the external buffer
is returned from the card to the driver. Add a counter that shows
how many times this allocation has failed. Note, that we could even
further delay the allocation of the mbuf until we know, that we need it
(there are no receive errors and the connection is open). This will be done
in a later commit.

Print the new statistics field in atmconfig.

Get rid of the mutexes for the exernal buffer free lists. Use
atomic instructions instead. Remove the stuff used to track
whether an external mbuf travels through the system. This is
temporary only and will come back soon.

When we cannot allocate an external buffer (bacause we've hit
the maximum number of pages for buffers) return -1 instead of 0.
This fixes a panic under conditions when many mbufs are needed.

Update the head pointer of the receive buffer pool queue even when
we could not supply a buffer to the chip. Otherwise the chip will
not re-interrupt us for another try. A better strategy would probably
be to remember this condition and to supply buffers without an interrupt
as soon as buffers get available.

Use __FBSDID().
Also some minor style cleanups.

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.

Use the default arguments for lockfunc and lockfuncarg in
bus_dma_tag_create. We need to be sure that our packets are
kept in-sequence (that's how ATM is supposed to work) and
therefor use BUS_DMA_NOWAIT in all calls to bus_dmamap_load.

For memory allocated with bus_dmamem_alloc the use of anything
other than NULL arguments for the locking is anyway bogus because
this memory never should need bouncing and hence the load should never
be defered.

Allow the receipt of OAM and RM cells on raw connections. Caveat: it seems
that RM cells are still processed by the hardware even when we open the
connection as UBR.

Style: __FBSDID().

This is a driver for Fore/Marconi HE155 and HE622 ATM cards. It is full
busdma and has extensively been tested on i386 and sparc64.