Doing max(1, foo) where foo is u32 generates a warning, because 1 is a
signed constant.  Fix this by using 1U instead.
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

Cast the increment added to wq->tail when send completions are
processed to u16 to avoid using wrong values caused by standard
integer promotions.

The same bug was fixed in libmlx4 by Eli Cohen <eli@mellanox.co.il>.
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

QPs attached to an SRQ must never have their own RQ, and QPs not
attached to SRQs must have an RQ with at least 1 entry.  Enforce all
of this in set_rq_size().

Based on a patch by Eli Cohen <eli@mellanox.co.il>.
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

next_port should be between sysctl_local_port_range[0] and [1].
However, it is initially set to a random value with get_random_bytes().  
If the value is negative when treated as a signed integer, next_port
can end up outside the expected range because of the result of the % 
operator being negative.
Signed-off-by: NSean Hefty <sean.hefty@intel.com>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

The code in __mlx4_ib_modify_qp() overwrites context->params1 after
the RNR retry parameter is ORed in, which results in the RNR retry
parameter always being set to 0.  Fix this by moving where we OR in
the value to later in the function, after the initial assignment of
context->params1.

Found by the Mellanox firmware group.
Signed-off-by: NJack Morgenstein <jackm@dev.mellanox.co.il>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

This patch converts the ipv4_devconf config members (everything except
sysctl) to an array.  This allows easier manipulation which will be
needed later on to provide better management of default config values.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

s/signifant/significant/
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

The ib_cm can incorrectly detect a stale connection (a new connection
request for a QPN that is already connected) as a duplicate connection
request.  Separate the handling of potential duplicate REQs from stale
connections.
Signed-off-by: NSean Hefty <sean.hefty@intel.com>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

commit 518b1646 ("IPoIB/cm: Fix SRQ WR leak") introduced a severe
performance regression on Mellanox cards, because keeping a QP in the
error state for extended periods of time moves hardware to the slow
path (until the QP is destroyed).  For example, MPI latency goes from
~3 usecs to ~7 usecs.

Fix this by posting a send WR on one of the QPs that are being
flushed, instead of using a separate drain QP that is kept in the
error state.

This fixes bug <https://bugs.openfabrics.org/show_bug.cgi?id=636>,
reported and bisected by Scott Weitzenkamp at Cisco and debugged by
Sasha Mikheev at Voltaire.
Signed-off-by: NMichael S. Tsirkin <mst@dev.mellanox.co.il>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

mthca_free_err_wqe() currently treats both send and receive CQEs
identically if a QP is using an SRQ.  But for Tavor hardware, send
CQEs with error can be chained together even if the RQ is part of SRQ,
so we may miss some CQEs.

Fix by following the WQE chain for all send CQEs even for non-SRQ QPs.

This fixes crashes in IPoIB CM:
<https://bugs.openfabrics.org//show_bug.cgi?id=604>
Signed-off-by: NMichael S. Tsirkin <mst@dev.mellanox.co.il>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

Since NAPI polling is disabled while ipoib_cm_dev_stop() is running,
ipoib_cm_dev_stop() must poll the CQ itself in order to see the
packets draining.
Signed-off-by: NMichael S. Tsirkin <mst@dev.mellanox.co.il>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

time_after() was used backwards, so the timeout occurred immediately.
Signed-off-by: NMichael S. Tsirkin <mst@dev.mellanox.co.il>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

Due to a typo, the driver was reporting the wrong number of "actual send
WRs" after ehca_create_qp().
Signed-off-by: NJoachim Fenkes <fenkes@de.ibm.com>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

We need to initialize the owner bit of send queue WQEs to hardware 
ownership whenever the QP is modified from reset to init, not just 
when the QP is first allocated.  This avoids having the hardware 
process stale WQEs when the QP is moved to reset but not destroyed and 
then modified to init again. 
Signed-off-by: NEli Cohen <eli@mellanox.co.il>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

If a QP is attached to a shared receive queue (SRQ), then it doesn't
have a receive queue (RQ).  So don't allocate an RQ doorbell (or map a
doorbell from userspace for userspace QPs) for that QP.
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

The IB CM uses an idr for local id allocations, with a running counter
as start_id.  This fails to generate distinct ids if

1. An id is constantly created and destroyed
2. A chunk of ids just beyond the current next_id value is occupied

This in turn leads to an increased chance of connection request being
mis-detected as a duplicate, sometimes for several retries, until
next_id gets past the block of allocated ids. This has been observed
in practice.

As a fix, remember the last id allocated and start immediately above it.
This also fixes a problem with the old code, where next_id might
overflow and become negative.
Signed-off-by: NMichael S. Tsirkin <mst@dev.mellanox.co.il>
Acked-by: NSean Hefty <sean.hefty@intel.com>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

SRQ WR leakage has been observed with IPoIB/CM: e.g. flipping ports on
and off will, with time, leak out all WRs and then all connections
will start getting RNR NAKs.  Fix this in the way suggested by spec:
move the QP being destroyed to the error state, wait for "Last WQE
Reached" event and then post WR on a "drain QP" connected to the same
CQ.  Once we observe a completion on the drain QP, it's safe to call
ib_destroy_qp.
Signed-off-by: NMichael S. Tsirkin <mst@dev.mellanox.co.il>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

Trivial error message fixups.
Signed-off-by: NMichael S. Tsirkin <mst@dev.mellanox.co.il>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

First thing mm.h does is including sched.h solely for can_do_mlock() inline
function which has "current" dereference inside. By dealing with can_do_mlock()
mm.h can be detached from sched.h which is good. See below, why.

This patch
a) removes unconditional inclusion of sched.h from mm.h
b) makes can_do_mlock() normal function in mm/mlock.c
c) exports can_do_mlock() to not break compilation
d) adds sched.h inclusions back to files that were getting it indirectly.
e) adds less bloated headers to some files (asm/signal.h, jiffies.h) that were
   getting them indirectly

Net result is:
a) mm.h users would get less code to open, read, preprocess, parse, ... if
   they don't need sched.h
b) sched.h stops being dependency for significant number of files:
   on x86_64 allmodconfig touching sched.h results in recompile of 4083 files,
   after patch it's only 3744 (-8.3%).

Cross-compile tested on

	all arm defconfigs, all mips defconfigs, all powerpc defconfigs,
	alpha alpha-up
	arm
	i386 i386-up i386-defconfig i386-allnoconfig
	ia64 ia64-up
	m68k
	mips
	parisc parisc-up
	powerpc powerpc-up
	s390 s390-up
	sparc sparc-up
	sparc64 sparc64-up
	um-x86_64
	x86_64 x86_64-up x86_64-defconfig x86_64-allnoconfig

as well as my two usual configs.
Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Make mlx4_post_srq_recv() fail if the SRQ is full (head == tail).
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

Pass the number of WQEs for the send queue and their size from userspace
to the kernel to avoid having to keep the QP size calculations in sync 
between the kernel driver and libmlx4.  This fixes a bug seen with the 
current mlx4_ib driver and current libmlx4 caused by a difference in the 
calculated sizes for SQ WQEs.  Also, this gives more flexibility for 
userspace to experiment with using multiple WQE BBs for a single SQ WQE.
Signed-off-by: NEli Cohen <eli@mellanox.co.il>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

wr->opcode is invalid if it's >= ARRAY_SIZE(mlx4_ib_opcode), not just
strictly >.

This was spotted by the Coverity checker (CID 1643).
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

According to the IB spec, a QP can be moved from RESET back to RESET
or to the ERROR state, but mlx4 firmware does not support this and
returns an error if we try.  Fix the RESET to RESET transition by
just returning 0 without doing anything, and fix RESET to ERROR by
moving the QP from RESET to INIT with dummy parameters and then
transitioning from INIT to ERROR.
Signed-off-by: NMichael S. Tsirkin <mst@dev.mellanox.co.il>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

According to the IB spec, a QP can be moved from RESET to the ERROR 
state, but mthca firmware does not support this and returns an error if 
we try.  Work around this FW limitation by moving the QP from RESET to
INIT with dummy parameters and then transitioning from INIT to ERROR.
Signed-off-by: NMichael S. Tsirkin <mst@dev.mellanox.co.il>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

This is the same issue discovered in mthca by Rolf Manderscheid
<rvm@obsidianresearch.com>.
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

Global CM packets used by rmda_cm were being sent with a GRH:hopLimit
of zero, causing them to be dropped by the router.  The problem is a
missing initialization of the hop_limit field in mthca_read_ah(),
which was called by build_mlx_header() when sending a MAD on QP1.
Signed-off-by: NRolf Manderscheid <rvm@obsidianresearch.com>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

max_qp_dest_rdma is already in natural units - no need to shift.  This
was discovered by a test that deliberately requests more outstanding
atomic operation than the device supports.

Found by Sagi Rotem at Mellanox.
Signed-off-by: NEli Cohen <eli@mellanox.co.il>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

Signed-off-by: NMichael S. Tsirkin <mst@dev.mellanox.co.il>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

Set the return code of ehca_register_mr() to ENOMEM if the corresponding
firmware call fails due to out of resources.  Some other error codes
were explicitly mapped to EINVAL -- just remove those cases so they
get mapped to the default case, which already returns EINVAL anyway.
Signed-off-by: NHoang-Nam Nguyen <hnguyen@de.ibm.com>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

SM reconfiguration or failover possibly causes a shuffling of the values
in the P_Key table. Right now, IPoIB only queries for the P_Key index
once when it creates the device QP, and hence there are problems if the
index of a P_Key value changes.  Fix this by using the PKEY_CHANGE event
to trigger a recheck of the P_Key index.
Signed-off-by: NYosef Etigin <yosefe@voltaire.com>
Acked-by: NMichael S. Tsirkin <mst@dev.mellanox.co.il>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

Clean up ib_query_port() and ib_modify_port() slightly by using the 
just-added start_port() and end_port() helpers.
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

Add ib_find_gid() and ib_find_pkey() functions that use uncached device
queries.  The calls might block but the returns are always up-to-date.
Cache P_Key and GID table lengths in core to avoid extra port info queries.
Signed-off-by: NYosef Etigin <yosefe@voltaire.com>
Acked-by: NMichael S. Tsirkin <mst@dev.mellanox.co.il>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

Lockdep found the following potential deadlock between mcast_lock and
n_mcast_grps_lock: mcast_lock is taken from both interrupt context and
process context, so spin_lock_irqsave() must be used to take it.
n_mcast_grps_lock is only taken from process context, so at first it
seems safe to take it with plain spin_lock(); however, it also nests
inside mcast_lock, and hence we could deadlock:

  cpu A                                   cpu B
    ipath_mcast_add():
      spin_lock_irq(&mcast_lock);

                                            ipath_mcast_detach():
                                              spin_lock(&n_mcast_grps_lock);

                                            <enter interrupt>

                                            ipath_mcast_find():
                                              spin_lock_irqsave(&mcast_lock);

      spin_lock(&n_mcast_grps_lock);

Fix this by using spin_lock_irq() to take n_mcast_grps_lock.
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

Free umem when task's mm is already destroyed by the time
ib_umem_release gets called.

Found by Dotan Barak at Mellanox.
Signed-off-by: NEli Cohen <eli@mellanox.co.il>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

In the presence of some running RX connections, we repeat
queue_delayed_work calls each 4 RX WRs, which is a waste.  It's enough
to start stale task when a first passive connection is added, and
rerun it every IPOIB_CM_RX_DELAY as long as there are outstanding
passive connections.

This removes some code from RX data path.
Signed-off-by: NMichael S. Tsirkin <mst@dev.mellanox.co.il>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

mthca_cq_clean() updates the CQ consumer index without moving CQEs
back to HW ownership.  As a result, the same WRID might get reported
twice, resulting in a use-after-free.  This was observed in IPoIB CM.
Fix by moving all freed CQEs to HW ownership.

This fixes <https://bugs.openfabrics.org/show_bug.cgi?id=617>
Signed-off-by: NMichael S. Tsirkin <mst@dev.mellanox.co.il>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

Fix posting lists of > 255 receive WRs for Tavor: rq.next_ind must
be updated each doorbell, otherwise the next doorbell will use an
incorrect index.

Found by Ronni Zimmermann at Mellanox.
Signed-off-by: NMichael S. Tsirkin <mst@dev.mellanox.co.il>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

Several checks in the rdma_cm check against the state of the
cm_id, but only to validate that the cm_id is bound to an underlying
transport specific CM and an RDMA device.  Make the check explicit
in what we're trying to check for, since we're not synchronizing
against the cm_id state.

This will allow a user to disconnect a cm_id or reject a connection
after receiving a device removal event.
Signed-off-by: NSean Hefty <sean.hefty@intel.com>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

The cma_iw_handler needs to validate the state of the rdma_cm_id before
processing a new connection request to ensure that a device removal is
not already being processed for the same rdma_cm_id.  Without the state
check, the user can receive simultaneous callbacks for the same cm_id, or
a callback after they've destroyed the cm_id.
Signed-off-by: NSean Hefty <sean.hefty@intel.com>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

Add a new routine and rename another to encapsulate common code for
synchronizing with device removal.
Signed-off-by: NSean Hefty <sean.hefty@intel.com>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>