Various drivers use xmit_lock internally to synchronise with their
transmission routines. They do so without setting xmit_lock_owner.
This is fine as long as netpoll is not in use.
With netpoll it is possible for deadlocks to occur if xmit_lock_owner
isn't set. This is because if a printk occurs while xmit_lock is held
and xmit_lock_owner is not set can cause netpoll to attempt to take
xmit_lock recursively.
While it is possible to resolve this by getting netpoll to use
trylock, it is suboptimal because netpoll's sole objective is to
maximise the chance of getting the printk out on the wire. So
delaying or dropping the message is to be avoided as much as possible.
So the only alternative is to always set xmit_lock_owner. The
following patch does this by introducing the netif_tx_lock family of
functions that take care of setting/unsetting xmit_lock_owner.
I renamed xmit_lock to _xmit_lock to indicate that it should not be
used directly. I didn't provide irq versions of the netif_tx_lock
functions since xmit_lock is meant to be a BH-disabling lock.
This is pretty much a straight text substitution except for a small
bug fix in winbond. It currently uses
netif_stop_queue/spin_unlock_wait to stop transmission. This is
unsafe as an IRQ can potentially wake up the queue. So it is safer to
use netif_tx_disable.
The hamradio bits used spin_lock_irq but it is unnecessary as
xmit_lock must never be taken in an IRQ handler.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently, all userspace verbs operations that call into the kernel
are serialized by ib_uverbs_idr_mutex. This can be a scalability
issue for some workloads, especially for devices driven by the ipath
driver, which needs to call into the kernel even for datapath
operations.
Fix this by adding reference counts to the userspace objects, and then
converting ib_uverbs_idr_mutex into a spinlock that only protects the
idrs long enough to take a reference on the object being looked up.
Because remove operations may fail, we have to do a slightly funky
two-step deletion, which is described in the comments at the top of
uverbs_cmd.c.
This also still leaves ib_uverbs_idr_lock as a single lock that is
possibly subject to contention. However, the lock hold time will only
be a single idr operation, so multiple threads should still be able to
make progress, even if ib_uverbs_idr_lock is being ping-ponged.
Surprisingly, these changes even shrink the object code:
add/remove: 23/5 grow/shrink: 4/21 up/down: 633/-693 (-60)
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Documentation/infiniband/core_locking.txt says:
All of the methods in struct ib_device exported by a low-level
driver must be fully reentrant. The low-level driver is required to
perform all synchronization necessary to maintain consistency, even
if multiple function calls using the same object are run
simultaneously.
However, mthca's modify_qp, modify_srq and resize_cq methods are
currently not reentrant. Add a mutex to the QP, SRQ and CQ structures
so that these calls can be properly serialized.
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Some error paths after the mthca_alloc_mailbox() call in mthca_modify_qp()
just do a "return -EINVAL" without freeing the mailbox. Convert these
returns to "goto out" to avoid leaking the mailbox storage.
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Factor out common code for adding a userspace object to an idr into a
function idr_add_uobj(). This shrinks both the source and object code:
add/remove: 1/0 grow/shrink: 0/6 up/down: 57/-220 (-163)
function old new delta
idr_add_uobj - 57 +57
ib_uverbs_create_ah 543 512 -31
ib_uverbs_create_srq 662 630 -32
ib_uverbs_reg_mr 737 699 -38
ib_uverbs_create_cq 639 600 -39
ib_uverbs_alloc_pd 485 446 -39
ib_uverbs_create_qp 1020 979 -41
Signed-off-by: Roland Dreier <rolandd@cisco.com>
In error paths when destroying an object, uverbs should not decrement
associated objects' usecnt, since ib_dereg_mr(), ib_destroy_qp(),
etc. already do that.
Signed-off-by: Roland Dreier <rolandd@cisco.com>
If ibdev->alloc_ucontext() fails then ib_uverbs_get_context() does not
unlock file->mutex before returning error.
Signed-off by: Ganapathi CH <cganapathi@novell.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Use new ib_init_ah_from_wc() and ib_init_ah_from_path() helper
functions to clean up the IB CM.
Signed-off-by: Sean Hefty <sean.hefty@intel.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Add a call to initialize address handle attributes given a path record.
This is used by the CM, and would be useful for users of UD QPs.
Signed-off-by: Sean Hefty <sean.hefty@intel.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Add a function to initialize address handle attributes from a work
completion. This functionality is duplicated by both verbs and the CM.
Signed-off-by: Sean Hefty <sean.hefty@intel.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
The P_Key is provided into a SIDR REQ in two places, once as a
parameter, and again in the path record. Remove the P_Key as a
parameter and always use the one given in the path record.
This change has no practical effect on ABI functionality.
Signed-off-by: Sean Hefty <sean.hefty@intel.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Misc cleanups in ib_srp:
1) I think that it is more efficient to move the req entries from req_list
to free_list in srp_reconnect_target (rather than rebuild the free_list).
(In any case this code is shorter).
2) This allows us to reuse code in srp_reset_device and srp_reconnect_target
and call a new function srp_reset_req.
Signed-off-by: Ishai Rabinovitz <ishai@mellanox.co.il>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
There has been a change in the format of port identifiers between
revision 10 of the SRP specification and the current revision 16A.
Revision 10 specifies port identifier format as
lower 8 bytes : GUID upper 8 bytes : Extension
Whereas revision 16A specifies it as
lower 8 bytes : Extension upper 8 bytes : GUID
There are older targets (e.g. SilverStorm Virtual Fibre Channel
Bridge) which conform to revision 10 of the SRP specification.
The I/O class of revision 10 is 0xFF00 and the I/O class of revision
16A is 0x0100.
For supporting older targets, this patch:
1) Adds a new optional target creation parameter "io_class". Default
value of io_class is 0x0100 (i.e. revision 16A)
2) Uses the correct port identifier format for targets with IO class
of 0xFF00 (i.e. conforming to revision 10)
Signed-off-by: Ramachandra K <rkuchimanchi@silverstorm.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
When creating a FMR pool, query the IB device and use the returned
max_map_map_per_fmr attribute as for the max number of FMR remaps. If
the device does not suport querying this attribute, use the original
IB_FMR_MAX_REMAPS (32) default.
Signed-off-by: Or Gerlitz <ogerlitz@voltaire.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Report the true max_map_per_fmr value from mthca_query_device(),
taking into account the change in FMR remapping introduced by the
Sinai performance optimization.
Signed-off-by: Or Gerlitz <ogerlitz@voltaire.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Change the mthca snoop of MADs that set PortInfo to check if the SM
has set the client reregister bit, and if it has, generate a client
reregister event. If the bit is not set, just generate a LID change
event as usual.
Signed-off-by: Leonid Arsh <leonida@voltaire.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Move ipath's struct port_info into <rdma/ib_smi.h>, so that it can be
used by mthca to implement client reregister support.
Remove the __attribute__((packed)) because all the members of the struct
are naturally aligned anyway.
Signed-off-by: Leonid Arsh <leonida@voltaire.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Handle client reregister events by treating them just like LID or
SM changes -- flush all cached paths and rejoin multicast groups.
Signed-off-by: Leonid Arsh <leonida@voltaire.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Fix misaligned access faults on ia64: never cast a misaligned
neighbour->ha + 4 pointer to union ib_gid type; pass a void * pointer
instead. The memcpy was being optimized to use full word accesses
because the compiler thought that union ib_gid is always aligned.
The cast in IPOIB_GID_ARG is safe, since it is fixed to access each
byte separately.
Signed-off-by: Jack Morgenstein <jackm@mellanox.co.il>
Signed-off-by: Michael S. Tsirkin <mst@mellanox.co.il>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
The comparisons of priv->tx_tail to ah->last_send in ipoib_free_ah()
and ipoib_post_receive() are slightly unsafe, because priv->tx_lock is
not held and hence a stale value of ah->last_send might be used, which
would lead to freeing an AH before the driver was really done with it.
The simple way to fix this is to the optimization of early free from
ipoib_free_ah() and unconditionally queue AHs for reaping, and then
take priv->tx_lock in __ipoib_reap_ah().
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Check GID/LID for requester side when searching for request which
matches received response. This is in order to guarantee uniqueness
if the same TID is used when requesting via multiple source LIDs (when
LMC is not zero). Use ports' cached LMC to perform the check.
Further, do not perform LID check for direct-routed packets, since
the permissive LID makes a proper check impossible.
Signed-off-by: Jack Morgenstein <jackm@mellanox.co.il>
Signed-off-by: Sean Hefty <sean.hefty@intel.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Add an LMC cache to struct ib_device, and add a function
ib_get_cached_lmc() to query the cache.
Signed-off-by: Jack Morgenstein <jackm@mellanox.co.il>
Signed-off-by: Sean Hefty <sean.hefty@intel.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
destroy_workqueue() already does flush_workqueue().
Signed-off-by: Michael S. Tsirkin <mst@mellanox.co.il>
Signed-off-by: Sean Hefty <sean.hefty@intel.com>
