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)
cards. This basically involves switching to the 12.4.13 firmware, plus
a couple of minor tweaks to the driver.
Also changed the jumbo buffer allocation scheme just a little to avoid
'failed to allocate jumbo buffer' conditions in certain cases.
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
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.
length for mini receive ring. The max length was MHLEN, however the mbufs
are actually shortened to MHLEN - ETHER_ALIGN to force payload alignment.
PR: 13793
This fixes, at least, panics in ncr_attach() on i386's with about 5MB
of memory. The restriction was a hack to leave some low memory for ISA
DMA, but on i386's we now allocate pages from the top down, so all the
restriction did was cause our allocations to fail when there is no free
memory above 1MB.
critical mbuf fields to sane values. Simplify the use of ETHER_ALIGN to
enforce payload alignment, and turn it on on the x86 as well as alpha
since it helps with NFS which wants the payload to be longword aligned
even though the hardware doesn't require it.
This fixes a problem with the ti driver causing an unaligned access trap
on the Alpha due to m_adj() sometimes not setting the alignment correctly
because of incomplete mbuf initialization.
in ti_rxeof() instead. This doesn't really seem to provide much in the
way of a performance boost, and I'm pretty sure it can cause mbuf leakage
in some extreme cases.
positively not let ti_encap() fill up the TX ring all the way and wrap
around. This fixes a potential transmit lockup where a really fast
machine (or particular TX traffic pattern) can overrun the end of the
ring.
Reported by: John Plevyak <jplevyak@inktomi.com>
in the transmit code: the TX descriptor ring, and a 'shadow' ring of mbuf
pointers, one for each TX descriptor. When transmitting a packet that
consists of several fragments in an mbuf chain, we link each fragment
to a descriptor in the TX ring, but we only save a pointer to the mbuf
chain. This pointer is saved in the shadow ring entry which corresponds
to the first fragment in the packet. Later, ti_txeof() can release the
whole chain with a single m_freem() call. (We need the second ring to
keep track of the virtual addresses of the mbuf chains.)
The problem with this is that the Tigon isn't actually through with the
mbuf chain until it reaches the last fragment (which has the TI_BDFLAG_END
bit set), however the current scheme releases the mbuf chain as soon as
the first fragment is consumed. This is wrong, since the mbufs can then
be yanked out from under the Tigon and modified before the other fragments
can be transmitted.
The fix is to make a one line change to ti_encap() so that it saves the
mbuf chain pointer in the shadow ring entry that corresponds to the last
fragment in TX ring instead of the first. This prevents the mbufs from
being released until the last fragment is transmitted.
Painstakingly diagnosed and fixed by: Robert Picco <picco@mail.wevinc.com>
Brought to my attention by: dg
#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.)
from ever catching up to the transmit consumer index. We can't let this
happen because ti_txeof() depends on the assumption that producer == consumer
means the ring is empty, and producer != consumer means the ring has some
number of active descriptors in it.
Oh, I forgot to mention: this driver also works on FreeBSD/alpha (big
thanks to Andrew Gallatin). And there is a 2.2.x version available for
those who stubbornly refuse to upgrade.
Networks Tigon 1 and Tigon 2 chipsets. There are a _lot_ of OEM'ed
gigabit ethernet adapters out there which use the Alteon chipset so
this driver covers a fair amount of hardware. I know that it works with
the Alteon AceNIC, 3Com 3c985 and Netgear GA620, however it should also
work with the DEC/Compaq EtherWORKS 1000, Silicon Graphics Gigabit
ethernet board, NEC Gigabit Ethernet board and maybe even the IBM and
and Sun boards. The Netgear board is the cheapest (~$350US) but still
yields fairly good performance.
Support is provided for jumbo frames with all adapters (just set the
MTU to something larger than 1500 bytes), as well as hardware multicast
filtering and vlan tagging (in conjunction with the vlan support in
-current, which I should merge into -stable soon). There are some hooks
for checksum offload support, but they're turned off for now since
FreeBSD doesn't have an officially sanctioned way to support checksum
offloading (yet).
I have not added the 'device ti0' entry to GENERIC since the driver
with all the firmware compiled in is quite large, and it doesn't really
fit into the category of generic hardware.
