that should be better.
The old code counted references to mbuf clusters by using the offset
of the cluster from the start of memory allocated for mbufs and
clusters as an index into an array of chars, which did the reference
counting. If the external storage was not a cluster then reference
counting had to be done by the code using that external storage.
NetBSD's system of linked lists of mbufs was cosidered, but Alfred
felt it would have locking issues when the kernel was made more
SMP friendly.
The system implimented uses a pool of unions to track external
storage. The union contains an int for counting the references and
a pointer for forming a free list. The reference counts are
incremented and decremented atomically and so should be SMP friendly.
This system can track reference counts for any sort of external
storage.
Access to the reference counting stuff is now through macros defined
in mbuf.h, so it should be easier to make changes to the system in
the future.
The possibility of storing the reference count in one of the
referencing mbufs was considered, but was rejected 'cos it would
often leave extra mbufs allocated. Storing the reference count in
the cluster was also considered, but because the external storage
may not be a cluster this isn't an option.
The size of the pool of reference counters is available in the
stats provided by "netstat -m".
PR: 19866
Submitted by: Bosko Milekic <bmilekic@dsuper.net>
Reviewed by: alfred (glanced at by others on -net)
ether_ifdetach().
The former consolidates the operations of if_attach(), ng_ether_attach(),
and bpfattach(). The latter consolidates the corresponding detach operations.
Reviewed by: julian, freebsd-net
of the individual drivers and into the common routine ether_input().
Also, remove the (incomplete) hack for matching ethernet headers
in the ip_fw code.
The good news: net result of 1016 lines removed, and this should make
bridging now work with *all* Ethernet drivers.
The bad news: it's nearly impossible to test every driver, especially
for bridging, and I was unable to get much testing help on the mailing
lists.
Reviewed by: freebsd-net
Note that if_aue doesn't strictly depend on usb because it uses the
method interface for calls rather than using internal symbols, and
because it's a child driver of usb and therefore will not try and do
anything unless the parent usb code is loaded at some point. if_aue does
strictly depend on miibus as it will fail to link if it is missing.
there are stubs compiled into the kernel if BPF support is not enabled,
there aren't any problems with unresolved symbols. The modules in /modules
are compiled with BPF support enabled anyway, so the most this will do is
bloat GENERIC a little.
declaration for the interface driver from "foo" to "if_foo" but leave the
declaration for the miibus attached to the interface driver alone. This
lets the internal module name be "if_foo" while still allowing the miibus
instances to attach to "foo."
This should allow ifconfig to autoload driver modules again without
breaking the miibus attach.
This whole idea isn't going to work until somebody makes the bus/kld
code smarter. The idea here is to change the module's internal name
from "foo" to "if_foo" so that ifconfig can tell a network driver from
a non-network one. However doing this doesn't work correctly no matter
how you slice it. For everything to work, you have to change the name
in both the driver_t struct and the DRIVER_MODULE() declaration. The
problems are:
- If you change the name in both places, then the kernel thinks that
the device's name is now "if_foo", so you get things like:
if_foo0: <FOO ethernet> irq foo at device foo on pcifoo
if_foo0: Ethernet address: foo:foo:foo:foo:foo:foo
This is bogus. Now the device name doesn't agree with the logical
interface name. There's no reason for this, and it violates the
principle of least astonishment.
- If you leave the name in the driver_t struct as "foo" and only
change the names in the DRIVER_MODULE() declaration to "if_foo" then
attaching drivers to child devices doesn't work because the names don't
agree. This breaks miibus: drivers that need to have miibuses and PHY
drivers attached never get them.
In other words: damned if you do, damned if you don't.
This needs to be thought through some more. Since the drivers that
use miibus are broken, I have to change these all back in order to
make them work again. Yes this will stop ifconfig from being able
to demand load driver modules. On the whole, I'd rather have that
than having the drivers not work at all.
compiles cleanly on the Alpha. (On the alpha, the port type is an int,
not a short).
Cast a couple of pointers to ints via 'uintptr_t' rather than 'unsigned
int' since uintptr_t is long (64 bit) on Alpha, as are pointers.
driver to use bus_space_read_foo()/bus_space_write_foo(). The line is not
visible unless you compile the driver to use PCI memory mapped mode, which
not done by default, but it should be fixed anyway.
#define COMPAT_PCI_DRIVER(name,data) DATA_SET(pcidevice_set,data)
.. to 2.2.x and 3.x if people think it's worth it. Driver writers can do
this if it's not defined. (The reason for this is that I'm trying to
progressively eliminate use of linker_sets where it hurts modularity and
runtime load capability, and these DATA_SET's keep getting in the way.)
- In wb_rxeof(), if the received packet is less than MINCLSIZE bytes,
copy it to an mbuf chain so as to be more frugal in our use of mbuf
clusters.
- The Winbond chip, like the ASIX, wants the 'TX interrupt request'
bit set in the _first_ fragment of a transmitted frame, not the
last. (At least the Winbond manual states this unambiguously; too
bad I wasn't paying attention when I read it the first time.)
- Turn off the transmit threshold mechanism (initialize the threshold
to 0). This effectively puts the chip in 'store and forward' mode
which seems to cut down on transmit errors a little. It may also
reduce transmit performace a bit, but I'm willing to do that if it
means better reliability.
The Winbond chip always includes the CRC with every received frame,
and I can't find anything in the Winbond manual that indicates you can
program it not to do this.
apparently possible) event that the transmit start routine is
called with and empty if_snd queue, bail out instead of dereferencing
unilitialized transmit list pointers and panicking.
PCI fast ethernet adapters, plus man pages.
if_pn.c: Netgear FA310TX model D1, LinkSys LNE100TX, Matrox FastNIC 10/100,
various other PNIC devices
if_mx.c: NDC Communications SOHOware SFA100 (Macronix 98713A), various
other boards based on the Macronix 98713, 98713A, 98715, 98715A
and 98725 chips
if_vr.c: D-Link DFE530-TX, other boards based on the VIA Rhine and
Rhine II chips (note: the D-Link and certain other cards
that actually use a Rhine II chip still return the PCI
device ID of the Rhine I. I don't know why, and it doesn't
really matter since the driver treats both chips the same
anyway.)
if_wb.c: Trendware TE100-PCIE and various other cards based on the
Winbond W89C840F chip (the Trendware card is identical to
the sample boards Winbond sent me, so who knows how many
clones there are running around)
All drivers include support for ifmedia, BPF and hardware multicast
filtering.
Also updated GENERIC, LINT, RELNOTES.TXT, userconfig and
sysinstall device list.
I also have a driver for the ASIX AX88140A in the works.
