The first switch statement in cm_destroy_id() tries to move the ID to
either IB_CM_IDLE or IB_CM_TIMEWAIT. Both states will block concurrent
MAD handlers from progressing.

Previous patches removed the unreliably lock/unlock sequences in this
flow, this patch removes the extra locking steps and adds the missing
parts to guarantee that destroy reaches IB_CM_IDLE. There is no point in
leaving the ID in the IB_CM_TIMEWAIT state the memory about to be kfreed.

Rework things to hold the lock across all the state transitions and
directly assert when done that it ended up in IB_CM_IDLE as expected.

This was accompanied by a careful audit of all the state transitions here,
which generally did end up in IDLE on their success and non-racy paths.

Link: https://lore.kernel.org/r/20200310092545.251365-16-leon@kernel.orgSigned-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

The first thing ib_send_cm_sidr_rep() does is obtain the lock, so use the
usual unlocked wrapper, locked actor pattern here.

Get rid of the cm_reject_sidr_req() wrapper so each call site can call the
locked or unlocked version as required.

This avoids a sketchy lock/unlock sequence (which could allow state to
change) during cm_destroy_id().

Link: https://lore.kernel.org/r/20200310092545.251365-15-leon@kernel.orgSigned-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

The first thing ib_send_cm_rej() does is obtain the lock, so use the usual
unlocked wrapper, locked actor pattern here.

This avoids a sketchy lock/unlock sequence (which could allow state to
change) during cm_destroy_id().

While here simplify some of the logic in the implementation.

Link: https://lore.kernel.org/r/20200310092545.251365-14-leon@kernel.orgSigned-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

The first thing ib_send_cm_drep() does is obtain the lock, so use the
usual unlocked wrapper, locked actor pattern here.

This avoids a sketchy lock/unlock sequence (which could allow state to
change) during cm_destroy_id().

Link: https://lore.kernel.org/r/20200310092545.251365-13-leon@kernel.orgSigned-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

The first thing ib_send_cm_dreq() does is obtain the lock, so use the
usual unlocked wrapper, locked actor pattern here.

This avoids a sketchy lock/unlock sequence (which could allow state to
change) during cm_destroy_id().

Link: https://lore.kernel.org/r/20200310092545.251365-12-leon@kernel.orgSigned-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

These functions all touch state, so must be called under the lock.
Inspection shows this is currently true.

Link: https://lore.kernel.org/r/20200310092545.251365-11-leon@kernel.orgSigned-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

All accesses to id.state must be done under the spinlock.

Fixes: a977049d ("[PATCH] IB: Add the kernel CM implementation")
Link: https://lore.kernel.org/r/20200310092545.251365-10-leon@kernel.orgSigned-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

ib_crate_cm_id() immediately places the id in the xarray, and publishes it
into the remote_id and remote_qpn rbtrees. This makes it visible to other
threads before it is fully set up.

It appears the thinking here was that the states IB_CM_IDLE and
IB_CM_REQ_RCVD do not allow any MAD handler or lookup in the remote_id and
remote_qpn rbtrees to advance.

However, cm_rej_handler() does take an action on IB_CM_REQ_RCVD, which is
not really expected by the design.

Make the whole thing clearer:
 - Keep the new cm_id out of the xarray until it is completely set up.
   This directly prevents MAD handlers and all rbtree lookups from seeing
   the pointer.
 - Move all the trivial setup right to the top so it is obviously done
   before any concurrency begins
 - Move the mutation of the cm_id_priv out of cm_match_id() and into the
   caller so the state transition is obvious
 - Place the manipulation of the work_list at the end, under lock, after
   the cm_id is placed in the xarray. The work_count cannot change on an
   ID outside the xarray.
 - Add some comments

Link: https://lore.kernel.org/r/20200310092545.251365-9-leon@kernel.orgSigned-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

ib_create_cm_id() immediately places the id in the xarray, so it is visible
to network traffic.

The state is initially set to IB_CM_IDLE and all the MAD handlers will
test this state under lock and refuse to advance from IDLE, so adding to
the xarray is harmless.

Further, the set to IB_CM_SIDR_REQ_RCVD also excludes all MAD handlers.

However, the local_id isn't even used for SIDR mode, and there will be no
input MADs related to the newly created ID.

So, make the whole flow simpler so it can be understood:
 - Do not put the SIDR cm_id in the xarray. This directly shows that there
   is no concurrency
 - Delete the confusing work_count and pending_list manipulations. This
   mechanism is only used by MAD handlers and timewait, neither of which
   apply to SIDR.
 - Add a few comments and rename 'cur_cm_id_priv' to 'listen_cm_id_priv'
 - Move other loose sets up to immediately after cm_id creation so that
   the cm_id is fully configured right away. This fixes an oversight where
   the service_id will not be returned back on a IB_SIDR_UNSUPPORTED
   reject.

Link: https://lore.kernel.org/r/20200310092545.251365-8-leon@kernel.orgSigned-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

The lock should not be dropped before doing the pr_debug() print as it is
accessing data protected by the lock, such as id.state.

Fixes: 119bf817 ("IB/cm: Add debug prints to ib_cm")
Link: https://lore.kernel.org/r/20200310092545.251365-7-leon@kernel.orgSigned-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

Any manipulation of cm_id->state must be done under the cm_id_priv->lock,
the two routines that added listens did not follow this rule, because they
never participate in any concurrent access around the state.

However, since this exception makes the code hard to understand, simplify
the flow so that it can be fully locked:
 - Move manipulation of listen_sharecount into cm_insert_listen() so it is
   trivially under the cm.lock without having to expose the cm.lock to the
   caller.
 - Push the cm.lock down into cm_insert_listen() and have the function
   increment the reference count before returning an existing pointer.
 - Split ib_cm_listen() into an cm_init_listen() and do not call
   ib_cm_listen() from ib_cm_insert_listen()
 - Make both ib_cm_listen() and ib_cm_insert_listen() directly call
   cm_insert_listen() under their cm_id_priv->lock which does both a
   collision detect and, if needed, the insert (atomically)
 - Enclose all state manipulation within the cm_id_priv->lock, notice this
   set can be done safely after cm_insert_listen() as no reader is allowed
   to read the state without holding the lock.
 - Do not set the listen cm_id in the xarray, as it is never correct to
   look it up. This makes the concurrency simpler to understand.

Many needless error unwinds are removed in the process.

Link: https://lore.kernel.org/r/20200310092545.251365-6-leon@kernel.orgSigned-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

Too much of the destruction is very carefully sensitive to the state
and various other things. Move more code to the unconditional path and
add several WARN_ONs to check consistency.

Link: https://lore.kernel.org/r/20200310092545.251365-5-leon@kernel.orgSigned-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

When creating a cm_id during REQ the id immediately becomes visible to the
other MAD handlers, and shortly after the state is moved to IB_CM_REQ_RCVD

This allows cm_rej_handler() to run concurrently and free the work:

        CPU 0                                CPU1
 cm_req_handler()
  ib_create_cm_id()
  cm_match_req()
    id_priv->state = IB_CM_REQ_RCVD
                                       cm_rej_handler()
                                         cm_acquire_id()
                                         spin_lock(&id_priv->lock)
                                         switch (id_priv->state)
  					   case IB_CM_REQ_RCVD:
                                            cm_reset_to_idle()
                                             kfree(id_priv->timewait_info);
   goto destroy
  destroy:
    kfree(id_priv->timewait_info);
                                             id_priv->timewait_info = NULL

Causing a double free or worse.

Do not free the timewait_info without also holding the
id_priv->lock. Simplify this entire flow by making the free unconditional
during cm_destroy_id() and removing the confusing special case error
unwind during creation of the timewait_info.

This also fixes a leak of the timewait if cm_destroy_id() is called in
IB_CM_ESTABLISHED with an XRC TGT QP. The state machine will be left in
ESTABLISHED while it needed to transition through IB_CM_TIMEWAIT to
release the timewait pointer.

Also fix a leak of the timewait_info if the caller mis-uses the API and
does ib_send_cm_reqs().

Fixes: a977049d ("[PATCH] IB: Add the kernel CM implementation")
Link: https://lore.kernel.org/r/20200310092545.251365-4-leon@kernel.orgSigned-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

The test here typod the cm_id_priv to use, it used the one that was
freshly allocated. By definition the allocated one has the matching
cm_handler and zero context, so the condition was always true.

Instead check that the existing listening ID is compatible with the
proposed handler so that it can be shared, as was originally intended.

Fixes: 067b171b ("IB/cm: Share listening CM IDs")
Link: https://lore.kernel.org/r/20200310092545.251365-3-leon@kernel.orgSigned-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

xa_alloc_cyclic() is a SMP release to be paired with some later acquire
during xa_load() as part of cm_acquire_id().

As such, xa_alloc_cyclic() must be done after the cm_id is fully
initialized, in particular, it absolutely must be after the
refcount_set(), otherwise the refcount_inc() in cm_acquire_id() may not
see the set.

As there are several cases where a reader will be able to use the
id.local_id after cm_acquire_id in the IB_CM_IDLE state there needs to be
an unfortunate split into a NULL allocate and a finalizing xa_store.

Fixes: a977049d ("[PATCH] IB: Add the kernel CM implementation")
Link: https://lore.kernel.org/r/20200310092545.251365-2-leon@kernel.orgSigned-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

These judgments were used to keep the compatibility with older versions of
userspace that don't have the field named "cap_flags" in structure
hns_roce_ib_create_cq_resp. But it will be wrong to compare outlen with
the size of resp if another new field were added in resp. oulen should be
compared with the end offset of cap_flags in resp.

Fixes: 4f8f0d5e ("RDMA/hns: Package the flow of creating cq")
Link: https://lore.kernel.org/r/1583845569-47257-1-git-send-email-liweihang@huawei.comSigned-off-by: Weihang Li <liweihang@huawei.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

Leon Romanovsky says:

====================
This series fixes various corner cases in the mlx5_ib MR cache
implementation, see specific commit messages for more information.
====================

Based on the mlx5-next branch at
 git://git.kernel.org/pub/scm/linux/kernel/git/mellanox/linux
Due to dependencies

* branch 'mlx5_mr-cache':
  RDMA/mlx5: Allow MRs to be created in the cache synchronously
  RDMA/mlx5: Revise how the hysteresis scheme works for cache filling
  RDMA/mlx5: Fix locking in MR cache work queue
  RDMA/mlx5: Lock access to ent->available_mrs/limit when doing queue_work
  RDMA/mlx5: Fix MR cache size and limit debugfs
  RDMA/mlx5: Always remove MRs from the cache before destroying them
  RDMA/mlx5: Simplify how the MR cache bucket is located
  RDMA/mlx5: Rename the tracking variables for the MR cache
  RDMA/mlx5: Replace spinlock protected write with atomic var
  {IB,net}/mlx5: Move asynchronous mkey creation to mlx5_ib
  {IB,net}/mlx5: Assign mkey variant in mlx5_ib only
  {IB,net}/mlx5: Setup mkey variant before mr create command invocation

If the cache is completely out of MRs, and we are running in cache mode,
then directly, and synchronously, create an MR that is compatible with the
cache bucket using a sleeping mailbox command. This ensures that the
thread that is waiting for the MR absolutely will get one.

When a MR allocated in this way becomes freed then it is compatible with
the cache bucket and will be recycled back into it.

Deletes the very buggy ent->compl scheme to create a synchronous MR
allocation.

Link: https://lore.kernel.org/r/20200310082238.239865-13-leon@kernel.orgSigned-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

Currently if the work queue is running then it is in 'hysteresis' mode and
will fill until the cache reaches the high water mark. This implicit state
is very tricky and doesn't interact with pending very well.

Instead of self re-scheduling the work queue after the add_keys() has
started to create the new MR, have the queue scheduled from
reg_mr_callback() only after the requested MR has been added.

This avoids the bad design of an in-rush of queue'd work doing back to
back add_keys() until EAGAIN then sleeping. The add_keys() will be paced
one at a time as they complete, slowly filling up the cache.

Also, fix pending to be only manipulated under lock.

Link: https://lore.kernel.org/r/20200310082238.239865-12-leon@kernel.orgSigned-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

All of the members of mlx5_cache_ent must be accessed while holding the
spinlock, add the missing spinlock in the __cache_work_func().

Using cache->stopped and flush_workqueue() is an inherently racy way to
shutdown self-scheduling work on a queue. Replace it with ent->disabled
under lock, and always check disabled before queuing any new work. Use
cancel_work_sync() to shutdown the queue.

Use READ_ONCE/WRITE_ONCE for dev->last_add to manage concurrency as
coherency is less important here.

Split fill_delay from the bitfield. C bitfield updates are not atomic and
this is just a mess. Use READ_ONCE/WRITE_ONCE, but this could also use
test_bit()/set_bit().

Link: https://lore.kernel.org/r/20200310082238.239865-11-leon@kernel.orgSigned-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

Accesses to these members needs to be locked. There is no reason not to
hold a spinlock while calling queue_work(), so move the tests into a
helper and always call it under lock.

The helper should be called when available_mrs is adjusted.

Link: https://lore.kernel.org/r/20200310082238.239865-10-leon@kernel.orgSigned-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

The size_write function is supposed to adjust the total_mr's to match the
user's request, but lacks locking and safety checking.

total_mrs can only be adjusted by at most available_mrs. mrs already
assigned to users cannot be revoked. Ensure that the user provides a
target value within the range of available_mrs and within the high/low
water mark.

limit_write has confusing and wrong sanity checking, and doesn't have the
ability to deallocate on limit reduction.

Since both functions use the same algorithm to adjust the available_mrs,
consolidate it into one function and write it correctly. Fix the locking
and by holding the spinlock for all accesses to ent->X.

Always fail if the user provides a malformed string.

Fixes: e126ba97 ("mlx5: Add driver for Mellanox Connect-IB adapters")
Link: https://lore.kernel.org/r/20200310082238.239865-9-leon@kernel.orgSigned-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

The cache bucket tracks the total number of MRs that exists, both inside
and outside of the cache. Removing a MR from the cache (by setting
cache_ent to NULL) without updating total_mrs will cause the tracking to
leak and be inflated.

Further fix the rereg_mr path to always destroy the MR. reg_create will
always overwrite all the MR data in mlx5_ib_mr, so the MR must be
completely destroyed, in all cases, before this function can be
called. Detach the MR from the cache and unconditionally destroy it to
avoid leaking HW mkeys.

Fixes: afd14174 ("IB/mlx5: Use direct mkey destroy command upon UMR unreg failure")
Fixes: 56e11d62 ("IB/mlx5: Added support for re-registration of MRs")
Link: https://lore.kernel.org/r/20200310082238.239865-8-leon@kernel.orgSigned-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

There are many bad APIs here that are accepting a cache bucket index
instead of a bucket pointer. Many of the callers already have a bucket
pointer, so this results in a lot of confusing uses of order2idx().

Pass the struct mlx5_cache_ent into add_keys(), remove_keys(), and
alloc_cached_mr().

Once the MR is in the cache, store the cache bucket pointer directly in
the MR, replacing the 'bool allocated_from cache'.

In the end there is only one place that needs to form index from order,
alloc_mr_from_cache(). Increase the safety of this function by disallowing
it from accessing cache entries in the ODP special area.

Link: https://lore.kernel.org/r/20200310082238.239865-7-leon@kernel.orgSigned-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

The old names do not clearly indicate the intent.

Link: https://lore.kernel.org/r/20200310082238.239865-6-leon@kernel.orgSigned-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

mkey variant calculation was spinlock protected to make it atomic, replace
that with one atomic variable.

Link: https://lore.kernel.org/r/20200310082238.239865-4-leon@kernel.orgSigned-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

As mlx5_ib is the only user of the mlx5_core_create_mkey_cb, move the
logic inside mlx5_ib and cleanup the code in mlx5_core.
Signed-off-by: Michael Guralnik <michaelgur@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>

mkey variant is not required for mlx5_core use, move the mkey variant
counter to mlx5_ib.
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>

On reg_mr_callback() mlx5_ib is recalculating the mkey variant which is
wrong and will lead to using a different key variant than the one
submitted to firmware on create mkey command invocation.

To fix this, we store the mkey variant before invoking the firmware
command and use it later on completion (reg_mr_callback).
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Reviewed-by: Eli Cohen <eli@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>

Peer to peer support was never implemented, so delete it to make code less
clutter.

Link: https://lore.kernel.org/r/20200310091438.248429-6-leon@kernel.orgSigned-off-by: Leon Romanovsky <leonro@mellanox.com>
Reviewed-by: Mark Zhang <markz@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

Convert mlx5 driver to use offsetofend() instead of its duplicated
variant.

Link: https://lore.kernel.org/r/20200310091438.248429-5-leon@kernel.orgSigned-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

Convert mlx4 to use in-kernel offsetofend() instead
of its duplicated implementation.

Link: https://lore.kernel.org/r/20200310091438.248429-3-leon@kernel.orgSigned-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

Until now the flex parser capability was used in ib_query_device() to
indicate tunnel_offloads_caps support for mpls_over_gre/mpls_over_udp.

Newer devices and firmware will have configurations with the flexparser
but without mpls support.

Testing for the flex parser capability was a mistake, the tunnel_stateless
capability was intended for detecting mpls and was introduced at the same
time as the flex parser capability.

Otherwise userspace will be incorrectly informed that a future device
supports MPLS when it does not.

Link: https://lore.kernel.org/r/20200305123841.196086-1-leon@kernel.org
Cc: <stable@vger.kernel.org> # 4.17
Fixes: e818e255 ("IB/mlx5: Expose MPLS related tunneling offloads")
Signed-off-by: Alex Vesker <valex@mellanox.com>
Reviewed-by: Ariel Levkovich <lariel@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

Those macros are already defined in include/linux/mlx5/driver.h, so delete
their duplicate variants.

Link: https://lore.kernel.org/r/20200310075706.238592-1-leon@kernel.orgSigned-off-by: Ariel Levkovich <lariel@mellanox.com>
Signed-off-by: Yevgeny Kliteynik <kliteyn@mellanox.com>
Signed-off-by: Erez Shitrit <erezsh@mellanox.com>
Reviewed-by: Alex Vesker <valex@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

The header file rdma_core.h is duplicate, so let's remove it.

Fixes: 622db5b6 ("RDMA/core: Add trace points to follow MR allocation")
Link: https://lore.kernel.org/r/20200310091656.249696-1-leon@kernel.orgSigned-off-by: Zhu Yanjun <yanjunz@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

'wqe' is already zeroed at the top of the 'while' loop, just a few lines
below, and is not used outside of the loop.

So there is no need to zero it again, or for the variable to be declared
outside the loop.

Link: https://lore.kernel.org/r/20200308065442.5415-1-christophe.jaillet@wanadoo.frSigned-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

This lock ordering only happens when bonding is enabled and a certain
bonding related event fires. However, since it can happen this is a global
restriction on lock ordering.

Teach lockdep about the order directly and unconditionally so bugs here
are found quickly.

See https://syzkaller.appspot.com/bug?extid=55de90ab5f44172b0c90

Link: https://lore.kernel.org/r/20200227203651.GA27185@ziepe.caSigned-off-by: Jason Gunthorpe <jgg@mellanox.com>

Since RDMA rw API support operations with P2P memory sg list, make sure to
map/unmap the scatter list for signature operation correctly.

Link: https://lore.kernel.org/r/20200220100819.41860-2-maxg@mellanox.comSigned-off-by: Max Gurtovoy <maxg@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

Required due to dependencies in following patches.
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

Yishai Hadas Says:

====================
Expose raw packet pacing APIs to be used by DEVX based applications.  The
existing code was refactored to have a single flow with the new raw APIs.
====================

Based on the mlx5-next branch at
 git://git.kernel.org/pub/scm/linux/kernel/git/mellanox/linux
Due to dependencies

* branch 'mlx5_packet_pacing':
  IB/mlx5: Introduce UAPIs to manage packet pacing
  net/mlx5: Expose raw packet pacing APIs