In the MAD paravirtualization code, one of the checks performed when
forwarding QP1 (GSI) packets from wire to slave was a P_Key check: the
P_Key received in the MAD must be present in the guest's paravirtualized
P_Key table, and at least one of the (packet P_Key, guest P_Key) must
be a full-membership P_Key.
However, if everyone involved has only limited membership in the
default P_Key, then packets sent by full-member remote hosts arrive at
the PPF but are not passed on to the VFs with the current P_Key1 check.
Fix this as follows:
1. Don't care if P_Key received over wire is full or not. If it
successfully passed HW checks on the real QP1, then simply pass it
to guest regardless of whether the guest has full or limited
membership in its P_Key table.
2. If the guest (including paravirtualized master) has both full and
limited P_Key forms in its table, preferentially pass the
paravirtualized P_Key index of the full P_Key form in the tunnel
header.
3. In the multicast join flow (mlx4/mcg.c), use the index for the
default P_Key (wherever it is located) in replies generated from
within the mcg module (previously, P_Key index 0 was used in all
cases).
Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il>
Signed-off-by: Roland Dreier <roland@purestorage.com>
When we have VFs and PFs on same host, the VFs are activated within
the mlx4_core module before the mlx4_ib kernel module is loaded.
When the mlx4_ib module initializes the PF (master), it now creates
MAD paravirtualization contexts for any VFs that already active.
Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il>
Signed-off-by: Roland Dreier <roland@purestorage.com>
Previously, the structure of a guest's proxy QPs followed the
structure of the PPF special qps (qp0 port 1, qp0 port 2, qp1 port 1,
qp1 port 2, ...). The guest then did offset calculations on the
sqp_base qp number that the PPF passed to it in QUERY_FUNC_CAP().
This is now changed so that the guest does no offset calculations
regarding proxy or tunnel QPs to use. This change frees the PPF from
needing to adhere to a specific order in allocating proxy and tunnel
QPs.
Now QUERY_FUNC_CAP provides each port individually with its proxy
qp0, proxy qp1, tunnel qp0, and tunnel qp1 QP numbers, and these are
used directly where required (with no offset calculations).
To accomplish this change, several fields were added to the phys_caps
structure for use by the PPF and by non-SR-IOV mode:
base_sqpn -- in non-sriov mode, this was formerly sqp_start.
base_proxy_sqpn -- the first physical proxy qp number -- used by PPF
base_tunnel_sqpn -- the first physical tunnel qp number -- used by PPF.
The current code in the PPF still adheres to the previous layout of
sqps, proxy-sqps and tunnel-sqps. However, the PPF can change this
layout without affecting VF or (paravirtualized) PF code.
Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il>
Signed-off-by: Roland Dreier <roland@purestorage.com>
This is necessary in order to support > 1 VF/PF in a VM for software
that uses the node guid as a discriminator, such as librdmacm.
Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il>
Signed-off-by: Roland Dreier <roland@purestorage.com>
1. Allow only master to change node description.
2. Prevent AH leakage in send mads.
3. Take device part number from PCI structure, so that guests see the
VF part number (and not the PF part number).
4. Place the device revision ID into caps structure at startup.
5. SET_PORT in update_gids_task needs to go through wrapper on master.
6. In mlx4_ib_event(), PORT_MGMT_EVENT needs be handled in a work
queue on the master, since it propagates events to slaves using
GEN_EQE.
7. Do not support FMR on slaves.
8. Add spinlock to slave_event(), since it is called both in interrupt
context and in process context (due to 6 above, and also if
smp_snoop is used). This fix was found and implemented by Saeed
Mahameed <saeedm@mellanox.com>
Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il>
Signed-off-by: Roland Dreier <roland@purestorage.com>
This directory is added only for the master -- slaves do not have it.
The sysfs iov directory is used to manage and examine the port P_Key
and guid paravirtualization.
Under iov/ports, the administrator may examine the gid and P_Key tables
as they are present in the device (and as are seen in the "network
view" presented to the SM).
Under the iov/<pci slot number> directories, the admin may map the
index numbers in the physical tables (as under iov/ports) to the
paravirtualized index numbers that guests see.
For example, if the administrator, for port 1 on guest 2 maps physical
pkey index 10 to virtual index 1, then that guest, whenever it uses
its pkey index 1, will actually be using the real pkey index 10.
Based on patch from Erez Shitrit <erezsh@mellanox.com>
Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il>
Signed-off-by: Roland Dreier <roland@purestorage.com>
P_Key change and guid change events are not of interest to all slaves,
but only to those slaves which "see" the table slots whose contents
have change.
For example, if the guid at port 1, index 5 has changed in the PPF, we
wish to propagate the gid-change event only to the function which has
that guid index mapped to its port/guid table (in this case it is
slave #5). Other functions should not get the event, since the event
does not affect them.
Similarly with P_Keys -- P_Key change events are forwarded only to
slaves which have that P_Key index mapped to their virtual P_Key table.
Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il>
Signed-off-by: Roland Dreier <roland@purestorage.com>
For IB ports, we paravirtualize the GUID at index 0 on slaves. The
GUID at index 0 seen by a slave is the actual GUID occupying the GUID
table at the slave-id index.
The driver, by default, requests at startup time that subnet manager
populate its entire guid table with GUIDs. These guids are then mapped
(paravirtualized) to the slaves, and appear for each slave as its GUID
at index 0.
Until each slave has such a guid, its port status is DOWN.
The guid table is cached to support special QP paravirtualization, and
event propagation to slaves on guid change (we test to see if the guid
really changed before propagating an event to the slave).
To support this caching, add capability to __mlx4_ib_query_gid() to
obtain the network view (i.e., physical view) gid at index X, not just
the host (paravirtualized) view.
Based on a patch from Erez Shitrit <erezsh@mellanox.com>
Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il>
Signed-off-by: Roland Dreier <roland@purestorage.com>
In CM para-virtualization:
1. Incoming requests are steered to the correct vHCA according to the
embedded GID.
2. Communication IDs on outgoing requests are replaced by a globally
unique ID, generated by the PPF, since there is no synchronization
of ID generation between guests (and so these IDs are not
guaranteed to be globally unique). The guest's comm ID is stored,
and is returned to the response MAD when it arrives.
Signed-off-by: Amir Vadai <amirv@mellanox.co.il>
Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il>
Signed-off-by: Roland Dreier <roland@purestorage.com>
MCG paravirtualization support includes:
- Creating multicast groups by VFs, and keeping accounting of them
- Leaving multicast groups by VFs
- Updating SM only with real changes in the overall picture of MCGs status
- Creation of MGID=0 groups (let SM choose MGID)
Note that the MCG module maintains its own internal MCG object
reference counts. The reason for this is that the IB core is used to
track only the multicast groups joins generated by the PF it runs
over. The PF IB core layer is unaware of slaves, so it cannot be used
to keep track of MCG joins they generate.
Signed-off-by: Oren Duer <oren@mellanox.co.il>
Signed-off-by: Eli Cohen <eli@mellanox.com>
Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il>
Signed-off-by: Roland Dreier <roland@purestorage.com>
The MAD_IFC firmware command fulfills two functions.
First, it is used in the QP0/QP1 MAD-handling flow to obtain
information from the FW (for answering queries), and for setting
variables in the HCA (MAD SET packets).
For this, MAD_IFC should provide the FW (physical) view of the data.
This is the view that OpenSM needs. We call this the "network view".
In the second case, MAD_IFC is used by various verbs to obtain data
regarding the local HCA (e.g., ib_query_device()). We call this the
"host view".
This data needs to be paravirtualized.
MAD_IFC therefore needs a wrapper function, and also needs another
flag indicating whether it should provide the network view (when it is
called by ib_process_mad in special-qp packet handling), or the host
view (when it is called while implementing a verb).
There are currently 2 flag parameters in mlx4_MAD_IFC already:
ignore_bkey and ignore_mkey. These two parameters are replaced by a
single "mad_ifc_flags" parameter, with different bits set for each
flag. A third flag is added: "network-view/host-view".
Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il>
Signed-off-by: Roland Dreier <roland@purestorage.com>
Special QPs are paravirtualized.
vHCAs are not given direct access to QP0/1. Rather, these QPs are
operated by a special context hosted by the PF, which mediates access
to/from vHCAs. This is done by opening a "tunnel" per vHCA port per
QP0/1. A tunnel comprises a pair of UD QPs: a "Tunnel QP" in the
PF-context and a "Proxy QP" in the vHCA. All vHCA MAD traffic must
pass through the corresponding tunnel. vHCA QPs cannot be assigned to
VL15 and are denied of the well-known QKey.
Outgoing messages are "de-multiplexed" (i.e., directed to the wire via
the real special QP).
Incoming messages are "multiplexed" (i.e. steered by the PPF to the
correct VF or to the PF)
QP0 access is restricted to the PF vHCA. VF vHCAs also have (virtual)
QP0s, but they never receive any SMPs and all SMPs sent are discarded.
QP1 traffic is allowed for all vHCAs, but special care is required to
bridge the gap between the host and network views.
Specifically:
- Transaction IDs are mapped to guarantee uniqueness among vHCAs
- CM para-virtualization
o Incoming requests are steered to the correct vHCA according to the embedded GID
o Local communication IDs are mapped to ensure uniqueness among vHCAs
(see the patch that adds CM paravirtualization.)
- Multicast para-virtualization
o The PF context aggregates membership state from all vHCAs
o The SA is contacted only when the aggregate membership changes
o If the aggregate does not change, the PF context will provide the
requesting vHCA with the proper response.
(see the patch that adds multicast group paravirtualization)
Incoming MADs are steered according to:
- the DGID If a GRH is present
- the mapped transaction ID for response MADs
- the embedded GID in CM requests
- the remote communication ID in other CM messages
Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il>
Signed-off-by: Roland Dreier <roland@purestorage.com>
This requires:
1. Replacing the paravirtualized P_Key index (inserted by the guest)
with the real P_Key index.
2. For UD QPs, placing the guest's true source GID index in the
address path structure mgid field, and setting the ud_force_mgid
bit so that the mgid is taken from the QP context and not from the
WQE when posting sends.
3. For UC and RC QPs, placing the guest's true source GID index in the
address path structure mgid field.
4. For tunnel and proxy QPs, setting the Q_Key value reserved for that
proxy/tunnel pair.
Since not all the above adjustments occur in all the QP transitions,
the QP transitions require separate wrapper functions.
Secondly, initialize the P_Key virtualization table to its default
values: Master virtualized table is 1-1 with the real P_Key table,
guest virtualized table has P_Key index 0 mapped to the real P_Key
index 0, and all the other P_Key indices mapped to the reserved
(invalid) P_Key at index 127.
Finally, add logic in smp_snoop for maintaining the phys_P_Key_cache.
and generating events on the master only if a P_Key actually changed.
Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il>
Signed-off-by: Roland Dreier <roland@purestorage.com>
Allocate SR-IOV paravirtualization resources and MAD demuxing contexts
on the master.
This has two parts. The first part is to initialize the structures to
contain the contexts. This is done at master startup time in
mlx4_ib_init_sriov().
The second part is to actually create the tunneling resources required
on the master to support a slave. This is performed the master
detects that a slave has started up (MLX4_DEV_EVENT_SLAVE_INIT event
generated when a slave initializes its comm channel).
For the master, there is no such startup event, so it creates its own
tunneling resources when it starts up. In addition, the master also
creates the real special QPs. The ib_core layer on the master causes
creation of proxy special QPs, since the master is also
paravirtualized at the ib_core layer.
Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il>
Signed-off-by: Roland Dreier <roland@purestorage.com>
To allow easy paravirtualization of P_Key and GID table sizes, keep
paravirtualized sizes in mlx4_dev->caps, but save the actual physical
sizes from FW in struct: mlx4_dev->phys_cap.
In addition, in SR-IOV mode, do the following:
1. Reduce reported P_Key table size by 1.
This is done to reserve the highest P_Key index for internal use,
for declaring an invalid P_Key in P_Key paravirtualization.
We require a P_Key index which always contain an invalid P_Key
value for this purpose (i.e., one which cannot be modified by
the subnet manager). The way to do this is to reduce the
P_Key table size reported to the subnet manager by 1, so that
it will not attempt to access the P_Key at index #127.
2. Paravirtualize the GID table size to 1. Thus, each guest sees
only a single GID (at its paravirtualized index 0).
In addition, since we are paravirtualizing the GID table size to 1, we
add paravirtualization of the master GID event here (i.e., we do not
do ib_dispatch_event() for the GUID change event on the master, since
its (only) GUID never changes).
Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il>
Signed-off-by: Roland Dreier <roland@purestorage.com>
The port management change event can replace smp_snoop. If the
capability bit for this event is set in dev-caps, the event is used
(by the driver setting the PORT_MNG_CHG_EVENT bit in the async event
mask in the MAP_EQ fw command). In this case, when the driver passes
incoming SMP PORT_INFO SET mads to the FW, the FW generates port
management change events to signal any changes to the driver.
If the FW generates these events, smp_snoop shouldn't be invoked in
ib_process_mad(), or duplicate events will occur (once from the
FW-generated event, and once from smp_snoop).
In the case where the FW does not generate port management change
events smp_snoop needs to be invoked to create these events. The flow
in smp_snoop has been modified to make use of the same procedures as
in the fw-generated-event event case to generate the port management
events (LID change, Client-rereg, Pkey change, and/or GID change).
Port management change event handling required changing the
mlx4_ib_event and mlx4_dispatch_event prototypes; the "param" argument
(last argument) had to be changed to unsigned long in order to
accomodate passing the EQE pointer.
We also needed to move the definition of struct mlx4_eqe from
net/mlx4.h to file device.h -- to make it available to the IB driver,
to handle port management change events.
Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
Define pr_fmt and add some pr_debug prints.
Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il>
Signed-off-by: Roland Dreier <roland@purestorage.com>
In the current code, vendor-specific MADs (e.g with the FDR-10
attribute) are silently dropped by the driver, resulting in timeouts
at the sending side and inability to query/configure the relevant
feature. However, the ConnectX firmware is able to handle such MADs.
For unsupported attributes, the firmware returns a GET_RESPONSE MAD
containing an error status.
For example, for a FDR-10 node with LID 11:
# ibstat mlx4_0 1
CA: 'mlx4_0'
Port 1:
State: Active
Physical state: LinkUp
Rate: 40 (FDR10)
Base lid: 11
LMC: 0
SM lid: 24
Capability mask: 0x02514868
Port GUID: 0x0002c903002e65d1
Link layer: InfiniBand
Extended Port Query (EPI) vendor mad timeouts before the patch:
# smpquery MEPI 11 -d
ibwarn: [4196] smp_query_via: attr 0xff90 mod 0x0 route Lid 11
ibwarn: [4196] _do_madrpc: retry 1 (timeout 1000 ms)
ibwarn: [4196] _do_madrpc: retry 2 (timeout 1000 ms)
ibwarn: [4196] _do_madrpc: timeout after 3 retries, 3000 ms
ibwarn: [4196] mad_rpc: _do_madrpc failed; dport (Lid 11)
smpquery: iberror: [pid 4196] main: failed: operation EPI: ext port info query failed
EPI query works OK with the patch:
# smpquery MEPI 11 -d
ibwarn: [6548] smp_query_via: attr 0xff90 mod 0x0 route Lid 11
ibwarn: [6548] mad_rpc: data offs 64 sz 64
mad data
0000 0000 0000 0001 0000 0001 0000 0001
0000 0000 0000 0000 0000 0000 0000 0000
0000 0000 0000 0000 0000 0000 0000 0000
0000 0000 0000 0000 0000 0000 0000 0000
# Ext Port info: Lid 11 port 0
StateChangeEnable:...............0x00
LinkSpeedSupported:..............0x01
LinkSpeedEnabled:................0x01
LinkSpeedActive:.................0x01
Signed-off-by: Jack Morgenstein <jackm@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Acked-by: Ira Weiny <weiny2@llnl.gov>
Cc: <stable@vger.kernel.org>
Signed-off-by: Roland Dreier <roland@purestorage.com>
For SRIOV, some Hypervisor commands can be executed directly (native = 1).
Others should go through the command wrapper flow (for tracking resource
usage, for example, or for changing some HCA configurations that slaves
need to be notified of).
This patch sets the groundwork for this capability -- adding the correct
value of "native" in each case.
Note that if SRIOV is not activated, this parameter has no effect.
Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il>
Signed-off-by: David S. Miller <davem@davemloft.net>
Use the per port counter attached to all QPs created on that port to
implement port level packets/bytes performance counters a la IB.
Derived from a patch by Eli Cohen <eli@mellanox.co.il>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.co.il>
Signed-off-by: Roland Dreier <roland@purestorage.com>
ib_create_send_mad() can return ERR_PTR(-ENOMEM) here.
Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Add support for IBoE to mlx4_ib. The bulk of the code is handling the
new address vector fields; mlx4 needs the MAC address of a remote node
to include it in a WQE (for datagrams) or in the QP context (for
connected QPs). Address resolution is done by assuming all unicast
GIDs are either link-local IPv6 addresses.
Multicast group attach/detach needs to update the NIC's multicast
filters; but since attaching a QP to a multicast group can be done
before the QP is bound to a port, for IBoE we need to keep track of
all multicast groups that a QP is attached too before it transitions
from INIT to RTR (since it does not have a port in the INIT state).
Signed-off-by: Eli Cohen <eli@mellanox.co.il>
[ Many things cleaned up and otherwise monkeyed with; hope I didn't
introduce too many bugs. - Roland ]
Signed-off-by: Roland Dreier <rolandd@cisco.com>
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.
percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.
http://userweb.kernel.org/~tj/misc/slabh-sweep.py
The script does the followings.
* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.
* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.
* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.
The conversion was done in the following steps.
1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.
2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.
3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.
4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.
5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.
6. percpu.h was updated not to include slab.h.
7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).
* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig
8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.
Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.
Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
When snooping a PortInfo MAD, its client_reregister bit is checked.
If the bit is ON then a CLIENT_REREGISTER event is dispatched,
otherwise a LID_CHANGE event is dispatched. This way of decision
ignores the cases where the MAD changes the LID along with an
instruction to reregister (so a necessary LID_CHANGE event won't be
dispatched) or the MAD is neither of these (and an unnecessary
LID_CHANGE event will be dispatched).
This causes problems at least with IPoIB, which will do a "light"
flush on reregister, rather than the "heavy" flush required due to a
LID change.
Fix this by dispatching a CLIENT_REREGISTER event if the
client_reregister bit is set, but also compare the LID in the MAD to
the current LID. If and only if they are not identical then a
LID_CHANGE event is dispatched.
Signed-off-by: Moni Shoua <monis@voltaire.com>
Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il>
Signed-off-by: Yossi Etigin <yosefe@voltaire.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Multi-protocol adapters support different port types. Each consumer
of mlx4_core queries for supported port types; in particular mlx4_ib
can no longer assume that all physical ports belong to it. Port type
is configured through a sysfs interface. When the type of a port is
changed, all mlx4 interfaces are unregistered, and then registered
again with the new port types.
Signed-off-by: Yevgeny Petrilin <yevgenyp@mellanox.co.il>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
ConnectX HCAs support the IB_MGMT_CLASS_CONG_MGMT management class, so
process MADs of this class through the MAD_IFC firmware command.
Signed-off-by: Eli Cohen <eli@mellanox.co.il>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
A stray semicolon makes us inadvertently ignore the value of err.
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Add an InfiniBand driver for Mellanox ConnectX adapters. Because
these adapters can also be used as ethernet NICs and Fibre Channel
HBAs, the driver is split into two modules:
mlx4_core: Handles low-level things like device initialization and
processing firmware commands. Also controls resource allocation
so that the InfiniBand, ethernet and FC functions can share a
device without stepping on each other.
mlx4_ib: Handles InfiniBand-specific things; plugs into the
InfiniBand midlayer.
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Jack Morgenstein