This adds the DEVICE object. This object supports creating the context
that all objects are created from. Moreover, it supports executing
methods which are related to the device itself, such as QUERY_DEVICE.
This is a singleton object (per file instance).
All standard objects are put in the root structure. This root will later
on be used in drivers as the source for their whole parsing tree.
Later on, when new features are added, these drivers could mix this root
with other customized objects.
Signed-off-by: Matan Barak <matanb@mellanox.com>
Reviewed-by: Yishai Hadas <yishaih@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Switch all uverbs_type_attrs_xxxx with DECLARE_UVERBS_OBJECT
macros. This will be later used in order to embed the object
specific methods in the objects as well.
Signed-off-by: Matan Barak <matanb@mellanox.com>
Reviewed-by: Yishai Hadas <yishaih@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
In this ioctl interface, processing the command starts from
properties of the command and fetching the appropriate user objects
before calling the handler.
Parsing and validation is done according to a specifier declared by
the driver's code. In the driver, all supported objects are declared.
These objects are separated to different object namepsaces. Dividing
objects to namespaces is done at initialization by using the higher
bits of the object ids. This initialization can mix objects declared
in different places to one parsing tree using in this ioctl interface.
For each object we list all supported methods. Similarly to objects,
methods are separated to method namespaces too. Namespacing is done
similarly to the objects case. This could be used in order to add
methods to an existing object.
Each method has a specific handler, which could be either a default
handler or a driver specific handler.
Along with the handler, a bunch of attributes are specified as well.
Similarly to objects and method, attributes are namespaced and hashed
by their ids at initialization too. All supported attributes are
subject to automatic fetching and validation. These attributes include
the command, response and the method's related objects' ids.
When these entities (objects, methods and attributes) are used, the
high bits of the entities ids are used in order to calculate the hash
bucket index. Then, these high bits are masked out in order to have a
zero based index. Since we use these high bits for both bucketing and
namespacing, we get a compact representation and O(1) array access.
This is mandatory for efficient dispatching.
Each attribute has a type (PTR_IN, PTR_OUT, IDR and FD) and a length.
Attributes could be validated through some attributes, like:
(*) Minimum size / Exact size
(*) Fops for FD
(*) Object type for IDR
If an IDR/fd attribute is specified, the kernel also states the object
type and the required access (NEW, WRITE, READ or DESTROY).
All uobject/fd management is done automatically by the infrastructure,
meaning - the infrastructure will fail concurrent commands that at
least one of them requires concurrent access (WRITE/DESTROY),
synchronize actions with device removals (dissociate context events)
and take care of reference counting (increase/decrease) for concurrent
actions invocation. The reference counts on the actual kernel objects
shall be handled by the handlers.
objects
+--------+
| |
| | methods +--------+
| | ns method method_spec +-----+ |len |
+--------+ +------+[d]+-------+ +----------------+[d]+------------+ |attr1+-> |type |
| object +> |method+-> | spec +-> + attr_buckets +-> |default_chain+--> +-----+ |idr_type|
+--------+ +------+ |handler| | | +------------+ |attr2| |access |
| | | | +-------+ +----------------+ |driver chain| +-----+ +--------+
| | | | +------------+
| | +------+
| |
| |
| |
| |
| |
| |
| |
| |
| |
| |
+--------+
[d] = Hash ids to groups using the high order bits
The right types table is also chosen by using the high bits from
the ids. Currently we have either default or driver specific groups.
Once validation and object fetching (or creation) completed, we call
the handler:
int (*handler)(struct ib_device *ib_dev, struct ib_uverbs_file *ufile,
struct uverbs_attr_bundle *ctx);
ctx bundles attributes of different namespaces. Each element there
is an array of attributes which corresponds to one namespaces of
attributes. For example, in the usually used case:
ctx core
+----------------------------+ +------------+
| core: +---> | valid |
+----------------------------+ | cmd_attr |
| driver: | +------------+
|----------------------------+--+ | valid |
| | cmd_attr |
| +------------+
| | valid |
| | obj_attr |
| +------------+
|
| drivers
| +------------+
+> | valid |
| cmd_attr |
+------------+
| valid |
| cmd_attr |
+------------+
| valid |
| obj_attr |
+------------+
Signed-off-by: Matan Barak <matanb@mellanox.com>
Reviewed-by: Yishai Hadas <yishaih@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
We should report the network header type in the work completion so that
the kernel can infer the right RoCE type headers.
Reviewed-by: Bryan Tan <bryantan@vmware.com>
Signed-off-by: Aditya Sarwade <asarwade@vmware.com>
Signed-off-by: Adit Ranadive <aditr@vmware.com>
Reviewed-by: Yuval Shaia <yuval.shaia@oracle.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
For RoCE, ib_init_ah_from_wc() can follow the path
ib_init_ah_from_wc() ->
rdma_addr_find_l2_eth_by_grh() ->
rdma_resolve_ip()
and rdma_resolve_ip() will sleep in kzalloc() and wait_for_completion().
However, developers will not see any warnings if they use ib_init_ah_from_wc()
in an atomic context and test only on IB, because the function doesn't
sleep in that case.
Add a might_sleep() so that lockdep will catch bugs no matter what hardware is
used to test.
Signed-off-by: Roland Dreier <roland@purestorage.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
A couple of places in the CM do
spin_lock_irq(&cm_id_priv->lock);
...
if (cm_alloc_response_msg(work->port, work->mad_recv_wc, &msg))
However when the underlying transport is RoCE, this leads to a sleeping function
being called with the lock held - the callchain is
cm_alloc_response_msg() ->
ib_create_ah_from_wc() ->
ib_init_ah_from_wc() ->
rdma_addr_find_l2_eth_by_grh() ->
rdma_resolve_ip()
and rdma_resolve_ip() starts out by doing
req = kzalloc(sizeof *req, GFP_KERNEL);
not to mention rdma_addr_find_l2_eth_by_grh() doing
wait_for_completion(&ctx.comp);
to wait for the task that rdma_resolve_ip() queues up.
Fix this by moving the AH creation out of the lock.
Signed-off-by: Roland Dreier <roland@purestorage.com>
Reviewed-by: Sean Hefty <sean.hefty@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
The new ioctl based infrastructure either commits or rollbacks
all objects of the method as one transaction. In order to do
that, we introduce a notion of dealing with a collection of
objects that are related to a specific method.
This also requires adding a notion of a method and attribute.
A method contains a hash of attributes, where each bucket
contains several attributes. The attributes are hashed according
to their namespace which resides in the four upper bits of the id.
For example, an object could be a CQ, which has an action of CREATE_CQ.
This action has multiple attributes. For example, the CQ's new handle
and the comp_channel. Each layer in this hierarchy - objects, methods
and attributes is split into namespaces. The basic example for that is
one namespace representing the default entities and another one
representing the driver specific entities.
When declaring these methods and attributes, we actually declare
their specifications. When a method is executed, we actually
allocates some space to hold auxiliary information. This auxiliary
information contains meta-data about the required objects, such
as pointers to their type information, pointers to the uobjects
themselves (if exist), etc.
The specification, along with the auxiliary information we allocated
and filled is given to the finalize_objects function.
Signed-off-by: Matan Barak <matanb@mellanox.com>
Reviewed-by: Yishai Hadas <yishaih@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
The ioctl infrastructure treats all user-objects in the same manner.
It gets objects ids from the user-space and by using the object type
and type attributes mentioned in the object specification, it executes
this required method. Passing an object id from the user-space as
an attribute is carried out in three stages. The first is carried out
before the actual handler and the last is carried out afterwards.
The different supported operations are read, write, destroy and create.
In the first stage, the former three actions just fetches the object
from the repository (by using its id) and locks it. The last action
allocates a new uobject. Afterwards, the second stage is carried out
when the handler itself carries out the required modification of the
object. The last stage is carried out after the handler finishes and
commits the result. The former two operations just unlock the object.
Destroy calls the "free object" operation, taking into account the
object's type and releases the uobject as well. Creation just adds the
new uobject to the repository, making the object visible to the
application.
In order to abstract these details from the ioctl infrastructure
layer, we add uverbs_get_uobject_from_context and
uverbs_finalize_object functions which corresponds to the first
and last stages respectively.
Signed-off-by: Matan Barak <matanb@mellanox.com>
Reviewed-by: Yishai Hadas <yishaih@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Add document providing definitions of terms and core explanations
for tag matching (TM) protocols, eager and rendezvous,
TM application header, tag list manipulations and matching process.
Signed-off-by: Artemy Kovalyov <artemyko@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Pass to mlx5_core flag to enable rendezvous offload, list_size and CQ
when SRQ created with IB_SRQT_TM.
Signed-off-by: Artemy Kovalyov <artemyko@mellanox.com>
Reviewed-by: Yossi Itigin <yosefe@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Add support to new XRQ(eXtended shared Receive Queue)
hardware object. It supports SRQ semantics with addition
of extended receive buffers topologies and offloads.
Currently supports tag matching topology and rendezvouz offload.
Signed-off-by: Artemy Kovalyov <artemyko@mellanox.com>
Reviewed-by: Yossi Itigin <yosefe@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Add new SRQ type capable of new tag matching feature.
When SRQ receives a message it will search through the matching list
for the corresponding posted receive buffer. The process of searching
the matching list is called tag matching.
In case the tag matching results in a match, the received message will
be placed in the address specified by the receive buffer. In case no
match was found the message will be placed in a generic buffer until the
corresponding receive buffer will be posted. These messages are called
unexpected and their set is called an unexpected list.
Signed-off-by: Artemy Kovalyov <artemyko@mellanox.com>
Reviewed-by: Yossi Itigin <yosefe@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Add tm_list_size parameter to struct ib_uverbs_create_xsrq.
If SRQ type is tag-matching this field defines maximum size
of tag matching list. Otherwise, it is expected to be zero.
Signed-off-by: Artemy Kovalyov <artemyko@mellanox.com>
Reviewed-by: Yossi Itigin <yosefe@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Doug Ledford <dledford@redhat.com>
This patch adds new SRQ type - IB_SRQT_TM. The new SRQ type supports tag
matching and rendezvous offloads for MPI applications.
When SRQ receives a message it will search through the matching list
for the corresponding posted receive buffer. The process of searching
the matching list is called tag matching.
In case the tag matching results in a match, the received message will
be placed in the address specified by the receive buffer. In case no
match was found the message will be placed in a generic buffer until the
corresponding receive buffer will be posted. These messages are called
unexpected and their set is called an unexpected list.
Signed-off-by: Artemy Kovalyov <artemyko@mellanox.com>
Reviewed-by: Yossi Itigin <yosefe@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Before this change CQ attached to SRQ was part of XRC specific extension.
Moving CQ handle out makes it available to other types extending SRQ
functionality.
Signed-off-by: Artemy Kovalyov <artemyko@mellanox.com>
Reviewed-by: Yossi Itigin <yosefe@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Doug Ledford <dledford@redhat.com>
This patch adds following TM XRQ capabilities:
* max_rndv_hdr_size - Max size of rendezvous request message
* max_num_tags - Max number of entries in tag matching list
* max_ops - Max number of outstanding list operations
* max_sge - Max number of SGE in tag matching entry
* flags - the following flags are currently defined:
- IB_TM_CAP_RC - Support tag matching on RC transport
Signed-off-by: Artemy Kovalyov <artemyko@mellanox.com>
Reviewed-by: Yossi Itigin <yosefe@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Without this fix, ports configured on top of ixgbe miss link up
notifications. ibv_query_port() will continue to return IBV_PORT_DOWN even
though the port is up and working.
Fixes: 8700e3e7c4 ("Soft RoCE driver")
Signed-off-by: Andrew Boyer <andrew.boyer@dell.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
The current process is to first calculate the CRC and then copy the client
data into the packet. This leaves a window in which the packet contents and
CRC can get out of sync, if the client changes the data after the CRC is
calculated but before the data is copied.
By copying the data into the packet and then calculating the CRC directly
from the packet contents we eliminate the window.
This can be seen with qperf's ud_bi_bw test. This seems like very
strange/reckless client behavior, but whether the client has mangled its
data or not RXE should be able to transfer it reliably.
Fixes: 8700e3e7c4 ("Soft RoCE driver")
Signed-off-by: Andrew Boyer <andrew.boyer@dell.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
This fixes another path in rxe_requester() that might overlook stale SKBs,
preventing cleanup.
Fixes: 1217197142 ("rxe: fix broken receive queue draining")
Signed-off-by: Andrew Boyer <andrew.boyer@dell.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Replace sk_dst_get()/dst_release() in rxe_qp_cleanup() with sk_dst_reset().
sk_dst_get() takes a new reference on dst, so the dst_release() doesn't
actually release the original reference, which was the design intent.
Fixes: 4ed6ad1eb3 ("IB/rxe: Cache dst in QP instead of getting it...")
Signed-off-by: Andrew Boyer <andrew.boyer@dell.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
To successfully match an IPv6 path, the path cookie must match. Store it
in the QP so that the IPv6 path can be reused.
Replace open-coded version of dst_check() with the actual call, fixing the
logic. The open-coded version skips the check call if dst->obsolete is 0
(DST_OBSOLETE_NONE), proceeding to replace the route. DST_OBSOLETE_NONE
means that the route may continue to be used, though.
Fixes: 4ed6ad1eb3 ("IB/rxe: Cache dst in QP instead of getting it...")
Signed-off-by: Andrew Boyer <andrew.boyer@dell.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
The resource array is sized by max_dest_rd_atomic, not max_rd_atomic.
Iterating over max_rd_atomic entries of qp->resp.resources[] will cause
incorrect behavior when the two attributes are different (or even
crash if max_rd_atomic is larger).
Fixes: 8700e3e7c4 ("Soft RoCE driver")
Signed-off-by: Andrew Boyer <andrew.boyer@dell.com>
Reviewed-by: Yuval Shaia <yuval.shaia@oracle.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
This prevents the stack from accessing userspace objects while they
are being torn down.
One possible sequence of events:
- Userspace program exits
- ib_uverbs_cleanup_ucontext() runs, calling ib_destroy_qp(),
ib_destroy_cq(), etc. and releasing/freeing the UCQ
- The QP still has tasklets running, so it isn't destroyed yet
- The CQ is referenced by the QP, so the CQ isn't destroyed yet
- The UCQ is kfree()'d anyway
- A send work request completes
- rxe_send_complete() calls cq->ibcq.comp_handler()
- ib_uverbs_comp_handler() runs and crashes; the event queue is checked
for is_closed, but it has no way to check the ib_ucq_object before
accessing it
The reference counting on the CQ doesn't protect against this since the CQ
hasn't been destroyed yet.
There's no available interface to deregister the UCQ from the CQ, and it
didn't appear that attempting to add reference counting to the UCQ was
going to be a good way to go since this solution is much simpler.
Fixes: 8700e3e7c4 ("Soft RoCE driver")
Signed-off-by: Andrew Boyer <andrew.boyer@dell.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
The network stack will call nskb's destructor, rxe_skb_tx_dtor(), if the
packet gets dropped by ip_local_out()/ip6_local_out(). Thus we need to add
the QP ref before output to avoid extra dereferences during network
congestion. This could lead to unwanted destruction of the QP.
Fix up the skb_out accounting, too.
Fixes: fda85ce912 ("IB/rxe: Fix kernel panic from skb destructor")
Signed-off-by: Andrew Boyer <andrew.boyer@dell.com>
Acked-by: Moni Shoua <monis@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
A destroy of an MR prior to destroying the QP can cause the following
diagnostic if the QP is referencing the MR being de-registered:
hfi1 0000:05:00.0: hfi1_0: rvt_dereg_mr timeout mr ffff8808562108
00 pd ffff880859b20b00
The solution is to when the a non-zero refcount is encountered when
the MR is destroyed the QPs needs to be iterated looking for QPs in
the same PD as the MR. If rvt_qp_mr_clean() detects any such QP
references the rkey/lkey, the QP needs to be put into an error state
via a call to rvt_qp_error() which will trigger the clean up of any
stuck references.
This solution is as specified in IBTA 1.3 Volume 1 11.2.10.5.
[This is reproduced with the 0.4.9 version of qperf and the rc_bw test]
Reviewed-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Continue porting copy/paste code into rdmavt from qib.
Reviewed-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Change hfi1_error_port_qps() to use the new rvt_qp_iter() in its QP
scanning.
Reviewed-by: Kaike Wan <kaike.wan@intel.com>
Signed-off-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
There are currently 3 spots in the qib and hfi1 driver that have
knowledge of the internal QP hash list that should only be in
scope to rdmavt QP code.
Add an iterator API for processing all QPs to hide the
nature of the RCU hashlist.
The API consists of:
- rvt_qp_iter_init()
* For iterating QPs one at a time for seq_file semantics
- rvt_qp_iter_next()
* For iterating QPs one at a time for seq_file semantics
- rvt_qp_iter()
* For iterating all QPs
The first two are used for things like seq_file prints.
The last is for code that just needs to iterate all QPs
in the system.
Reviewed-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
The qp_stats print will soon be moving to rdmavt, so use the proper
accessor to get the ring size rather than a driver supplied constant.
Fixes: Commit ff8d836efe ("IB/hfi1: Add receiving queue info to qp_stats")
Reviewed-by: Kaike Wan <kaike.wan@intel.com>
Signed-off-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Replace 'strcpy' with 'strncpy' to restrict the number
of bytes copied to the buffer.
Reviewed-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Signed-off-by: Kamenee Arumugam <kamenee.arumugam@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
The hfi1_cdbg() macro can be instantiated in the hot path even when it
is not in use. This shows up on perf profiles.
Rework the macros (for SDMA and MMU), to use the trace interface directly
to eliminate this performance hit.
Reviewed-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Currently, QSFP information is not queried
in cases where loopback was set up and QSFP module is
present.
Acquire QSFP information in case of loopback.
Reviewed-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Jan Sokolowski <jan.sokolowski@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Make some structures const as they are only used during a copy
operation.
Signed-off-by: Bhumika Goyal <bhumirks@gmail.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
vm_operations_struct are not supposed to change at runtime.
vm_area_struct structure working with const vm_operations_struct.
So mark the non-const vm_operations_struct structs as const.
Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
call to memset to assign 0 value immediately after allocating
memory with kzalloc is unnecesaary as kzalloc allocates the memory
filled with 0 value.
Signed-off-by: Himanshu Jha <himanshujha199640@gmail.com>
Reviewed-by: Yuval Shaia <yuval.shaia@oracle.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
These fields allow for debugging send engine processing.
Reviewed-by: Kaike Wan <kaike.wan@intel.com>
Signed-off-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
The rvt_ack_entry pointed to by s_tail_ack_queue provides important
info about the request that has just been processed or is being processed
on the responder side of a RC connection. This patch adds this info to
the qp_stats to assist debugging.
Reviewed-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Kaike Wan <kaike.wan@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Clean up user_sdma.c by moving the structure and MACRO definitions into
the header file user_sdma.h
Reviewed-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Harish Chegondi <harish.chegondi@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Clean up user_exp_rcv.c file by moving structure definitions into header
file user_exp_rcv.h. Since these structure definitions depend on the
structure definitions in mmu_rb.h, move #include "mmu_rb.h" above
the include "user_exp_rcv.h" or include of header files that include
user_exp_rcv.h
Reviewed-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Harish Chegondi <harish.chegondi@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
num_user_pages() function has been defined in both user_exp_rcv.c file
and user_sdma.c file. Move the function definition to a header file so
there is only one definition in the source repo.
Reviewed-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Harish Chegondi <harish.chegondi@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
