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: NRoland 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: NRoland Dreier <rolandd@cisco.com>

If we post a list of length 256 exactly, nreq in doorbell gets set to
256 which is wrong: it should be encoded by 0.  This is because we
only zero it out on the next WR, which may not be there.  The solution
is to ring the doorbell after posting a WQE, not before posting the
next one.
Signed-off-by: NMichael S. Tsirkin <mst@mellanox.co.il>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

Fix races in in destroying various objects.  If a destroy routine
waits for an object to become free by doing

	wait_event(&obj->wait, !atomic_read(&obj->refcount));
	/* now clean up and destroy the object */

and another place drops a reference to the object by doing

	if (atomic_dec_and_test(&obj->refcount))
		wake_up(&obj->wait);

then this is susceptible to a race where the wait_event() and final
freeing of the object occur between the atomic_dec_and_test() and the
wake_up().  And this is a use-after-free, since wake_up() will be
called on part of the already-freed object.

Fix this in mthca by replacing the atomic_t refcounts with plain old
integers protected by a spinlock.  This makes it possible to do the
decrement of the reference count and the wake_up() so that it appears
as a single atomic operation to the code waiting on the wait queue.

While touching this code, also simplify mthca_cq_clean(): the CQ being
cleaned cannot go away, because it still has a QP attached to it.  So
there's no reason to be paranoid and look up the CQ by number; it's
perfectly safe to use the pointer that the callers already have.
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

Push translation of static rate to HCA format into low-level drivers,
where it belongs.  For static rate encoding, use encoding of rate
field from IB standard PathRecord, with addition of value 0, for
backwards compatibility with current usage.  The changes are:

 - Add enum ib_rate to midlayer includes.
 - Get rid of static rate translation in IPoIB; just use static rate
   directly from Path and MulticastGroup records.
 - Update mthca driver to translate absolute static rate into the
   format used by hardware.  This also fixes mthca's static rate
   handling for HCAs that are capable of 4X DDR.
Signed-off-by: NJack Morgenstein <jackm@mellanox.co.il>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

Quite a few cleanup functions in mthca were marked as __devexit.
However, they could also be called from error paths during
initialization, so they cannot be marked that way.  Just delete all of
the incorrect annotations.
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

If the call to mthca_MODIFY_QP() failed, then mthca_modify_qp() would
still do some things it shouldn't, such as store away attributes for
special QPs.  Fix this, and simplify the code, by simply jumping to
the exit path if mthca_MODIFY_QP() fails.
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

Fix some whitespace damage (indenting with spaces) that snuck in.
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

mthca_alloc_sqp() by mthca_set_qp_size() need to set qp->transport
before calling mthca_set_qp_size(), since the value is used there.
Signed-off-by: NJack Morgenstein <jackm@mellanox.co.il>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

Add a check that the modify QP parameters sgid_index and path_mtu are
valid, since they might come from userspace.
Signed-off-by: NDotan Barak <dotanb@mellanox.co.il>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

Check that the alternate P_Key index is in range when setting the
alternate path for a QP.  Also make a cosmetic touch up to the debug
message printed when the main P_Key index is out of range.
Signed-off-by: NDotan Barak <dotanb@mellanox.co.il>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

Add support for IB_SEND_FENCE flag in post_send methods.
Signed-off-by: NDotan Barak <dotanb@mellanox.co.il>
Signed-off-by: NMichael S. Tsirkin <mst@mellanox.co.il>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

Implement the query_qp and query_srq methods in mthca.
Signed-off-by: NEli Cohen <eli@mellanox.co.il>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

Use ib_modify_qp_is_ok() in mthca, and delete the big table of
attributes for queue pair state transitions.
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

Add low-level driver support to ib_mthca so that consumers can request
a "send queue drained" event be generated when a transiton to the SQD
state completes.
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

Remove trailing whitespace and fix indentation that with spaces
instead of tabs.
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

The function mthca_free_err_wqe() can never fail, so get rid of its
return value.  That means handle_error_cqe() doesn't have to check
what mthca_free_err_wqe() returns, which means it can't fail either
and doesn't have to return anything either.  All this results in
simpler source code and a slight object code improvement:

add/remove: 0/0 grow/shrink: 0/2 up/down: 0/-10 (-10)
function                                     old     new   delta
mthca_free_err_wqe                            83      81      -2
mthca_poll_cq                               1758    1750      -8
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

build_mlx_header() was using sqp->ud_header.grh_present before it was
initialized by mthca_read_ah().  Furthermore, header->grh_present is
set by ib_ud_header_init, so there's no need to set it again in
mthca_read_ah().
Signed-off-by: NMichael S. Tsirkin <mst@mellanox.co.il>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

Add code to modify QP operation to handle setting alternate paths for
connected QPs.
Signed-off-by: NDotan Barak <dotanb@mellanox.co.il>
Signed-off-by: NMichael S. Tsirkin <mst@mellanox.co.il>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

PKEY_INDEX is not a legal parameter in the RTR->RTS transition.
Signed-off-by: NJack Morgenstein <jackm@mellanox.co.il>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

Fixes to SQEr->RTS transition in modify_qp:
1. The flag IB_QP_ACCESS_FLAGS is optional for UC qps
2. The SQEr state is not supported for RC qps
Signed-off-by: NJack Morgenstein <jackm@mellanox.co.il>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

Fix a case where copying max_inline_data from a successful create_qp
capabilities output to create_qp input could cause EINVAL error:

mthca_set_qp_size must check max_inline_data directly against
max_desc_sz; checking qp->sq.max_gs is wrong since max_inline_data
depends on the qp type and does not involve max_sg.
Signed-off-by: NJack Morgenstein <jackm@mellanox.co.il>
Signed-off-by: NMichael S. Tsirkin <mst@mellanox.co.il>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

Modify_qp should check that the physical port number provided
is a legal value.
Signed-off-by: NJack Morgenstein <jackm@mellanox.co.il>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

sae and sre bits should only be set when setting sra_max.  Further, in
the old code, if the caller specifies max_rd_atomic = 0, the sre and
sae bits are still set, with the result that the QP ends up with
max_rd_atomic = 1 in effect.
Signed-off-by: NJack Morgenstein <jackm@mellanox.co.il>
Signed-off-by: NMichael S. Tsirkin <mst@mellanox.co.il>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

This patch corrects some corner cases in managing the RAE/RRE bits in
the mthca qp context.  These bits need to be zero if the user requests
max_dest_rd_atomic of zero.  The bits need to be restored to the value
implied by the qp access flags attribute in a previous (or the
current) modify-qp command if the dest_rd_atomic variable is changed
to non-zero.

In the current implementation, the following scenario will not work:
RESET-to-INIT 	set QP access flags to all disabled (zeroes)
INIT-to-RTR     set max_dest_rd_atomic=10, AND
		set qp_access_flags = IB_ACCESS_REMOTE_READ | IB_ACCESS_REMOTE_ATOMIC

The current code will incorrectly take the access-flags value set in
the RESET-to-INIT transition.

We can simplify, and correct, this IB_QP_ACCESS_FLAGS handling: it is
always safe to set qp access flags in the firmware command if either
of IB_QP_MAX_DEST_RD_ATOMIC or IB_QP_ACCESS_FLAGS is set, so let's
just set it to the correct value, always.
Signed-off-by: NJack Morgenstein <jackm@mellanox.co.il>
Signed-off-by: NMichael S. Tsirkin <mst@mellanox.co.il>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

Only change the driver's copy of the QP attributes in modify QP after
checking the modify QP command completed successfully.
Signed-off-by: NJack Morgenstein <jackm@mellanox.co.il>
Signed-off-by: NMichael S. Tsirkin <mst@mellanox.co.il>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

Fix thinko in rd_atomic calculation: ffs(x) - 1 does not find the next
power of 2 -- it should be fls(x - 1).
Signed-off-by: NJack Morgenstein <jackm@mellanox.co.il>
Signed-off-by: NMichael S. Tsirkin <mst@mellanox.co.il>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

Add limit checking on rd_atomic and dest_rd_atomic attributes:
especially for max_dest_rd_atomic, a value that is larger than HCA
capability can cause RDB overflow and corruption of another QP.
Signed-off-by: NJack Morgenstein <jackm@mellanox.co.il>
Signed-off-by: NMichael S. Tsirkin <mst@mellanox.co.il>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

On mem-free HCAs, when posting a long list of send requests, a
doorbell must be rung every 255 requests.  Add code to handle this.
Signed-off-by: NMichael S. Tsirkin <mst@mellanox.co.il>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

last pointer is not updated when QP is modified to reset state.  This
causes data corruption if WQEs are already posted on the queue.
Signed-off-by: NMichael S. Tsirkin <mst@mellanox.co.il>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

Calculation of QP capabilities still isn't exactly right in mthca:
max_send_sge/max_recv_sge fields returned in create_qp can exceed the
handware supported limits.
Signed-off-by: NMichael S. Tsirkin <mst@mellanox.co.il>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

Responder resources are only required to handle RDMA reads and atomic
operations, not RDMA writes.  So the driver should allow RDMA writes
even if responder resources are set to 0.  This is especially
important for the UC transport -- with the old code, it was impossible
to enable RDMA writes for UC QPs.
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

In Tavor mode, when posting a long list of receive work requests, a
doorbell must be rung every 256 requests.  Add code to do this when
required.
Signed-off-by: NMichael S. Tsirkin <mst@mellanox.co.il>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

The size of work requests for atomic operations was computed
incorrectly in mthca: all sizeofs need to be divided by 16.
Signed-off-by: NMichael S. Tsirkin <mst@mellanox.co.il>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

Move the computation of QP capabilities (max scatter/gather entries,
max inline data, etc) into the kernel, and have the uverbs module
return the values as part of the create QP response.  This keeps
precise knowledge of device limits in the low-level kernel driver.

This requires an ABI bump, so while we're making changes, get rid of
the max_sge parameter for the modify SRQ command -- it's not used and
shouldn't be there.
Signed-off-by: NJack Morgenstein <jackm@mellanox.co.il>
Signed-off-by: NMichael S. Tsirkin <mst@mellanox.co.il>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

Make sure that the P_Key index passed into mthca_modify_qp() is
within the device's P_Key table.
Signed-off-by: NJack Morgenstein <jackm@mellanox.co.il>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

I recently picked up my older work to remove unnecessary #includes of
sched.h, starting from a patch by Dave Jones to not include sched.h
from module.h. This reduces the number of indirect includes of sched.h
by ~300. Another ~400 pointless direct includes can be removed after
this disentangling (patch to follow later).
However, quite a few indirect includes need to be fixed up for this.

In order to feed the patches through -mm with as little disturbance as
possible, I've split out the fixes I accumulated up to now (complete for
i386 and x86_64, more archs to follow later) and post them before the real
patch.  This way this large part of the patch is kept simple with only
adding #includes, and all hunks are independent of each other.  So if any
hunk rejects or gets in the way of other patches, just drop it.  My scripts
will pick it up again in the next round.
Signed-off-by: NTim Schmielau <tim@physik3.uni-rostock.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The UC transport does not support RDMA reads or atomic operations, so
we shouldn't require or even allow the consumer to set attributes
relating to these operations for UC QPs.
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

Check the sizes of CQs, QPs and SRQs when creating objects, and fail
instead of creating too-big queues.  Also return real limits instead
of just plausible-sounding values from mthca_query_device().
Signed-off-by: NJack Morgenstein <jackm@mellanox.co.il>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

Clean up QP table array on device removal.
Signed-off-by: NMichael S. Tsirkin <mst@mellanox.co.il>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>