RDMA/rdmavt: Decouple QP and SGE lists allocations

The rdmavt QP has fields that are both needed for the control and data
path. Such mixed declaration caused to the very specific allocation flow
wit

RDMA/rdmavt: Decouple QP and SGE lists allocations

The rdmavt QP has fields that are both needed for the control and data
path. Such mixed declaration caused to the very specific allocation flow
with kzalloc_node and SGE list embedded into the struct rvt_qp.

This patch separates QP creation to two: regular memory allocation for the
control path and specific code for the SGE list, while the access to the
later is performed through derefenced pointer.

Such pointer and its context are expected to be in the cache, so
performance difference is expected to be negligible, if any exists.

Link: https://lore.kernel.org/r/f66c1e20ccefba0db3c69c58ca9c897f062b4d1c.1627040189.git.leonro@nvidia.com
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

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IB/rdmavt: Fix RQ counting issues causing use of an invalid RWQE

The lookaside count is improperly initialized to the size of the
Receive Queue with the additional +1. In the traces below, the
RQ s

IB/rdmavt: Fix RQ counting issues causing use of an invalid RWQE

The lookaside count is improperly initialized to the size of the
Receive Queue with the additional +1. In the traces below, the
RQ size is 384, so the count was set to 385.

The lookaside count is then rarely refreshed. Note the high and
incorrect count in the trace below:

rvt_get_rwqe: [hfi1_0] wqe ffffc900078e9008 wr_id 55c7206d75a0 qpn c
qpt 2 pid 3018 num_sge 1 head 1 tail 0, count 385
rvt_get_rwqe: (hfi1_rc_rcv+0x4eb/0x1480 [hfi1] <- rvt_get_rwqe) ret=0x1

The head,tail indicate there is only one RWQE posted although the count
says 385 and we correctly return the element 0.

The next call to rvt_get_rwqe with the decremented count:

rvt_get_rwqe: [hfi1_0] wqe ffffc900078e9058 wr_id 0 qpn c
qpt 2 pid 3018 num_sge 0 head 1 tail 1, count 384
rvt_get_rwqe: (hfi1_rc_rcv+0x4eb/0x1480 [hfi1] <- rvt_get_rwqe) ret=0x1

Note that the RQ is empty (head == tail) yet we return the RWQE at tail 1,
which is not valid because of the bogus high count.

Best case, the RWQE has never been posted and the rc logic sees an RWQE
that is too small (all zeros) and puts the QP into an error state.

In the worst case, a server slow at posting receive buffers might fool
rvt_get_rwqe() into fetching an old RWQE and corrupt memory.

Fix by deleting the faulty initialization code and creating an
inline to fetch the posted count and convert all callers to use
new inline.

Fixes: f592ae3c999f ("IB/rdmavt: Fracture single lock used for posting and processing RWQEs")
Link: https://lore.kernel.org/r/20200728183848.22226.29132.stgit@awfm-01.aw.intel.com
Reported-by: Zhaojuan Guo <zguo@redhat.com>
Cc: <stable@vger.kernel.org> # 5.4.x
Reviewed-by: Kaike Wan <kaike.wan@intel.com>
Signed-off-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Tested-by: Honggang Li <honli@redhat.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

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RDMA/include: Replace license text with SPDX tags

The header files in RDMA subsystem are dual licensed and can be
described by simple SPDX tag, so replace all of them at once
together with making th

RDMA/include: Replace license text with SPDX tags

The header files in RDMA subsystem are dual licensed and can be
described by simple SPDX tag, so replace all of them at once
together with making them use the same coding style for header
guard defines.

Link: https://lore.kernel.org/r/20200719072521.135260-1-leon@kernel.org
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

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IB/hfi1: Remove module parameter for KDETH qpns

The module parameter for KDETH qpns is being removed in favor
of always using the default value of 0x80 as the qpn prefix.
Defines have been added for

IB/hfi1: Remove module parameter for KDETH qpns

The module parameter for KDETH qpns is being removed in favor
of always using the default value of 0x80 as the qpn prefix.
Defines have been added for various KDETH values including
the prefix of 0x80.
The reserved range now starts at the base value for KDETH
qpns (0x80) and extends up to and including the last qpn for
other reserved QP prefixed types.
Adjust other QP prefixed define names to match KDETH defined
names.

Link: https://lore.kernel.org/r/20200511160600.173205.27508.stgit@awfm-01.aw.intel.com
Reviewed-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Reviewed-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Gary Leshner <Gary.S.Leshner@intel.com>
Signed-off-by: Kaike Wan <kaike.wan@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

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IB/rdmavt: Replace zero-length array with flexible-array

The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variab

IB/rdmavt: Replace zero-length array with flexible-array

The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:

struct foo {
int stuff;
struct boo array[];
};

By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.

Also, notice that, dynamic memory allocations won't be affected by
this change:

"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]

sizeof(flexible-array-member) triggers a warning because flexible array
members have incomplete type[1]. There are some instances of code in
which the sizeof operator is being incorrectly/erroneously applied to
zero-length arrays and the result is zero. Such instances may be hiding
some bugs. So, this work (flexible-array member conversions) will also
help to get completely rid of those sorts of issues.

This issue was found with the help of Coccinelle.

[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour")

Link: https://lore.kernel.org/r/20200507185342.GA14476@embeddedor
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

show more ...

RDMA: Replace zero-length array with flexible-array member

The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
vari

RDMA: Replace zero-length array with flexible-array member

The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:

struct foo {
int stuff;
struct boo array[];
};

By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.

Also, notice that, dynamic memory allocations won't be affected by
this change:

"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]

This issue was found with the help of Coccinelle.

[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour")

Link: https://lore.kernel.org/r/20200213010425.GA13068@embeddedor.com
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com> # added a few more

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IB/rdmavt: Correct comments in rdmavt_qp.h header

Comments need to be with the definition of rvt_restart_sge().

Other comments were duplicated in sw/rdmavt/rc.c and were removed.

Fixes: 385156c5f2

IB/rdmavt: Correct comments in rdmavt_qp.h header

Comments need to be with the definition of rvt_restart_sge().

Other comments were duplicated in sw/rdmavt/rc.c and were removed.

Fixes: 385156c5f2a6 ("IB/hfi: Move RC functions into a header file")
Link: https://lore.kernel.org/r/20191219211934.58387.88014.stgit@awfm-01.aw.intel.com
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: Jason Gunthorpe <jgg@mellanox.com>

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IB/{rdmavt, hfi1, qib}: Add a counter for credit waits

This patch adds a counter for credit waits to assist field debugging.

Link: https://lore.kernel.org/r/20190911113047.126040.10857.stgit@awfm-0

IB/{rdmavt, hfi1, qib}: Add a counter for credit waits

This patch adds a counter for credit waits to assist field debugging.

Link: https://lore.kernel.org/r/20190911113047.126040.10857.stgit@awfm-01.aw.intel.com
Reviewed-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-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: Jason Gunthorpe <jgg@mellanox.com>

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IB/hfi1: Unreserve a flushed OPFN request

When an OPFN request is flushed, the request is completed without
unreserving itself from the send queue. Subsequently, when a new
request is post sent, the

IB/hfi1: Unreserve a flushed OPFN request

When an OPFN request is flushed, the request is completed without
unreserving itself from the send queue. Subsequently, when a new
request is post sent, the following warning will be triggered:

WARNING: CPU: 4 PID: 8130 at rdmavt/qp.c:1761 rvt_post_send+0x72a/0x880 [rdmavt]
Call Trace:
[<ffffffffbbb61e41>] dump_stack+0x19/0x1b
[<ffffffffbb497688>] __warn+0xd8/0x100
[<ffffffffbb4977cd>] warn_slowpath_null+0x1d/0x20
[<ffffffffc01c941a>] rvt_post_send+0x72a/0x880 [rdmavt]
[<ffffffffbb4dcabe>] ? account_entity_dequeue+0xae/0xd0
[<ffffffffbb61d645>] ? __kmalloc+0x55/0x230
[<ffffffffc04e1a4c>] ib_uverbs_post_send+0x37c/0x5d0 [ib_uverbs]
[<ffffffffc04e5e36>] ? rdma_lookup_put_uobject+0x26/0x60 [ib_uverbs]
[<ffffffffc04dbce6>] ib_uverbs_write+0x286/0x460 [ib_uverbs]
[<ffffffffbb6f9457>] ? security_file_permission+0x27/0xa0
[<ffffffffbb641650>] vfs_write+0xc0/0x1f0
[<ffffffffbb64246f>] SyS_write+0x7f/0xf0
[<ffffffffbbb74ddb>] system_call_fastpath+0x22/0x27

This patch fixes the problem by moving rvt_qp_wqe_unreserve() into
rvt_qp_complete_swqe() to simplify the code and make it less
error-prone.

Fixes: ca95f802ef51 ("IB/hfi1: Unreserve a reserved request when it is completed")
Link: https://lore.kernel.org/r/20190715164528.74174.31364.stgit@awfm-01.aw.intel.com
Cc: <stable@vger.kernel.org>
Reviewed-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Reviewed-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Kaike Wan <kaike.wan@intel.com>
Signed-off-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

show more ...

IB/{rdmavt, hfi1, qib}: Add helpers to hide SWQE WR details

Add some helper functions to hide struct rvt_swqe details.

Reviewed-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Mich

IB/{rdmavt, hfi1, qib}: Add helpers to hide SWQE WR details

Add some helper functions to hide struct rvt_swqe details.

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: Jason Gunthorpe <jgg@mellanox.com>

show more ...

IB/{rdmavt, hfi1, qib}: Remove AH refcount for UD QPs

Historically rdmavt destroy_ah() has returned an -EBUSY when the AH has a
non-zero reference count. IBTA 11.2.2 notes no such return value or e

IB/{rdmavt, hfi1, qib}: Remove AH refcount for UD QPs

Historically rdmavt destroy_ah() has returned an -EBUSY when the AH has a
non-zero reference count. IBTA 11.2.2 notes no such return value or error
case:

Output Modifiers:
- Verb results:
- Operation completed successfully.
- Invalid HCA handle.
- Invalid address handle.

ULPs never test for this error and this will leak memory.

The reference count exists to allow for driver independent progress
mechanisms to process UD SWQEs in parallel with post sends. The SWQE will
hold a reference count until the UD SWQE completes and then drops the
reference.

Fix by removing need to reference count the AH. Add a UD specific
allocation to each SWQE entry to cache the necessary information for
independent progress. Copy the information during the post send
processing.

Reviewed-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-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: Jason Gunthorpe <jgg@mellanox.com>

show more ...

IB/{hfi1, qib, rdmavt}: Put qp in error state when cq is full

When a completion queue is full, the associated queue pairs are not put
into the error state. According to the IBTA specification, this

IB/{hfi1, qib, rdmavt}: Put qp in error state when cq is full

When a completion queue is full, the associated queue pairs are not put
into the error state. According to the IBTA specification, this is a
violation.

Quote from IBTA spec:
C9-218: A Requester Class F error occurs when the CQ is inaccessible or
full and an attempt is made to complete a WQE. The Affected QP shall be
moved to the error state and affiliated asynchronous errors generated as
described in 11.6.3.1 Affiliated Asynchronous Events on page 678. The
current WQE and any subsequent WQEs are left in an unknown state.

C11-37: The CI shall generate a CQ Error when a CQ overrun is
detected. This condition will result in an Affiliated Asynchronous Error
for any associated Work Queues when they attempt to use that
CQ. Completions can no longer be added to the CQ. It is not guaranteed
that completions present in the CQ at the time the error occurred can be
retrieved. Possible causes include a CQ overrun or a CQ protection error.

Put the qp in error state when cq is full. Implement a state called full
to continue to put other associated QPs in error state.

Reviewed-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
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: Jason Gunthorpe <jgg@mellanox.com>

show more ...

IB/rdmavt: Fracture single lock used for posting and processing RWQEs

Usage of single lock prevents fetching posted and processing receive work
queue entries from progressing simultaneously and impa

IB/rdmavt: Fracture single lock used for posting and processing RWQEs

Usage of single lock prevents fetching posted and processing receive work
queue entries from progressing simultaneously and impacts overall
performance.

Fracture the single lock used for posting and processing Receive Work
Queue Entries (RWQEs) to allow the circular buffer to be filled and
emptied at the same time. Two new spinlocks - one for the producers and
one for the consumers used for posting and processing RWQEs simultaneously
and the two indices are define on two different cache lines. The threshold
count is used to avoid reading other index in different cache line every
time.

Signed-off-by: Harish Chegondi <harish.chegondi@intel.com>
Signed-off-by: Kamenee Arumugam <kamenee.arumugam@intel.com>
Reviewed-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

show more ...

IB/hfi1: Move receive work queue struct into uapi directory

The rvt_rwqe and rvt_rwq struct elements are shared between rdmavt and the
providers but are not in uapi directory. As per the comment in

IB/hfi1: Move receive work queue struct into uapi directory

The rvt_rwqe and rvt_rwq struct elements are shared between rdmavt and the
providers but are not in uapi directory. As per the comment in
https://marc.info/?l=linux-rdma&m=152296522708522&w=2, The hfi1 driver and
the rdma core driver are not using shared structures in the uapi
directory.

Move rvt_rwqe and rvt_rwq struct into rvt-abi.h header in uapi directory.

Reviewed-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
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: Jason Gunthorpe <jgg@mellanox.com>

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IB/hfi1: Move rvt_cq_wc struct into uapi directory

The rvt_cq_wc struct elements are shared between rdmavt and the providers
but not in uapi directory. As per the comment in
https://marc.info/?l=li

IB/hfi1: Move rvt_cq_wc struct into uapi directory

The rvt_cq_wc struct elements are shared between rdmavt and the providers
but not in uapi directory. As per the comment in
https://marc.info/?l=linux-rdma&m=152296522708522&w=2 The hfi1 driver and
the rdma core driver are not using shared structures in the uapi
directory.

In that case, move rvt_cq_wc struct into the rvt-abi.h header file and
create a rvt_k_cq_w for the kernel completion queue.

Signed-off-by: Kamenee Arumugam <kamenee.arumugam@intel.com>
Reviewed-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

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IB/{rdmavt, qib, hfi1}: Convert to new completion API

Convert all completions to use the new completion routine that
fixes a race between post send and completion where fields from
a SWQE can be rea

IB/{rdmavt, qib, hfi1}: Convert to new completion API

Convert all completions to use the new completion routine that
fixes a race between post send and completion where fields from
a SWQE can be read after SWQE has been freed.

This patch also addresses issues reported in
https://marc.info/?l=linux-kernel&m=155656897409107&w=2.

The reserved operation path has no need for any barrier.

The barrier for the other path is addressed by the
smp_load_acquire() barrier.

Cc: Andrea Parri <andrea.parri@amarulasolutions.com>
Reviewed-by: Michael J. Ruhl <michael.j.ruhl@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>

show more ...

IB/rdmavt: Add new completion inline

There is opencoded send completion logic all over all
the drivers.

We need to convert to this routine to enforce ordering
issues for completions. This routine

IB/rdmavt: Add new completion inline

There is opencoded send completion logic all over all
the drivers.

We need to convert to this routine to enforce ordering
issues for completions. This routine fixes an ordering
issue where the read of the SWQE fields necessary for creating
the completion can race with a post send if the post send catches
a send queue at the edge of being full. Is is possible in that situation
to read SWQE fields that are being written.

This new routine insures that SWQE fields are read prior to advancing
the index that post send uses to determine queue fullness.

Reviewed-by: Michael J. Ruhl <michael.j.ruhl@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>

show more ...

IB/{rdmavt, qib, hfi1}: Use new routine to release reference counts

The reference count adjustments on reference count completion
are open coded throughout.

Add a routine to do all reference count

IB/{rdmavt, qib, hfi1}: Use new routine to release reference counts

The reference count adjustments on reference count completion
are open coded throughout.

Add a routine to do all reference count adjustments and use.

Reviewed-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Signed-off-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

show more ...

IB/rdmavt: Fix ab/ba include issues

The currently include file ordering for rdmavt headers has an
ab/ba include issue the precludes using inlines from rdma_vt.h
in rdmavt_qp.h.

At the heart of the

IB/rdmavt: Fix ab/ba include issues

The currently include file ordering for rdmavt headers has an
ab/ba include issue the precludes using inlines from rdma_vt.h
in rdmavt_qp.h.

At the heart of the issue is that rdma_vt.h includes rdmavt_qp.h.

Fix the ordering issue by adjusting rdma_vt.h to not require rdmavt_qp.h
and move qp related inlines to rdmavt_qp.h.

Additionally, promote rvt_mmap_info to rdma_vt.h since it is shared
by rdmavt_cq.h and rdmavt_qp.h.

Reviewed-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Signed-off-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

show more ...

IB/{rdmavt, hfi1): Miscellaneous comment fixes

This patch fixes miscellaneous comment errors.

Reviewed-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Kaike Wan <kaike.wan@intel.co

IB/{rdmavt, hfi1): Miscellaneous comment fixes

This patch fixes miscellaneous comment errors.

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: Jason Gunthorpe <jgg@mellanox.com>

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IB/hfi1: Add TID RDMA WRITE functionality into RDMA verbs

This patch integrates TID RDMA WRITE protocol into normal RDMA verbs
framework. The TID RDMA WRITE protocol is an end-to-end protocol
betwee

IB/hfi1: Add TID RDMA WRITE functionality into RDMA verbs

This patch integrates TID RDMA WRITE protocol into normal RDMA verbs
framework. The TID RDMA WRITE protocol is an end-to-end protocol
between the hfi1 drivers on two OPA nodes that converts a qualified
RDMA WRITE request into a TID RDMA WRITE request to avoid data copying
on the responder side.

Reviewed-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Mitko Haralanov <mitko.haralanov@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>

show more ...

IB/hfi1: Add an s_acked_ack_queue pointer

The s_ack_queue is managed by two pointers into the ring:
r_head_ack_queue and s_tail_ack_queue. r_head_ack_queue is the index of
where the next received re

IB/hfi1: Add an s_acked_ack_queue pointer

The s_ack_queue is managed by two pointers into the ring:
r_head_ack_queue and s_tail_ack_queue. r_head_ack_queue is the index of
where the next received request is going to be placed and s_tail_ack_queue
is the entry of the request currently being processed. This works
perfectly fine for normal Verbs as the requests are processed one at a
time and the s_tail_ack_queue is not moved until the request that it
points to is fully completed.

In this fashion, s_tail_ack_queue constantly chases r_head_ack_queue and
the two pointers can easily be used to determine "queue full" and "queue
empty" conditions.

The detection of these two conditions are imported in determining when an
old entry can safely be overwritten with a new received request and the
resources associated with the old request be safely released.

When pipelined TID RDMA WRITE is introduced into this mix, things look
very different. r_head_ack_queue is still the point at which a newly
received request will be inserted, s_tail_ack_queue is still the
currently processed request. However, with pipelined TID RDMA WRITE
requests, s_tail_ack_queue moves to the next request once all TID RDMA
WRITE responses for that request have been sent. The rest of the protocol
for a particular request is managed by other pointers specific to TID RDMA
- r_tid_tail and r_tid_ack - which point to the entries for which the next
TID RDMA DATA packets are going to arrive and the request for which
the next TID RDMA ACK packets are to be generated, respectively.

What this means is that entries in the ring, which are "behind"
s_tail_ack_queue (entries which s_tail_ack_queue has gone past) are no
longer considered complete. This is where the problem is - a newly
received request could potentially overwrite a still active TID RDMA WRITE
request.

The reason why the TID RDMA pointers trail s_tail_ack_queue is that the
normal Verbs send engine uses s_tail_ack_queue as the pointer for the next
response. Since TID RDMA WRITE responses are processed by the normal Verbs
send engine, s_tail_ack_queue had to be moved to the next entry once all
TID RDMA WRITE response packets were sent to get the desired pipelining
between requests. Doing otherwise would mean that the normal Verbs send
engine would not be able to send the TID RDMA WRITE responses for the next
TID RDMA request until the current one is fully completed.

This patch introduces the s_acked_ack_queue index to point to the next
request to complete on the responder side. For requests other than TID
RDMA WRITE, s_acked_ack_queue should always be kept in sync with
s_tail_ack_queue. For TID RDMA WRITE request, it may fall behind
s_tail_ack_queue.

Reviewed-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Mitko Haralanov <mitko.haralanov@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>

show more ...

IB/hfi1: Increment the retry timeout value for TID RDMA READ request

The RC retry timeout value is based on the estimated time for the
response packet to come back. However, for TID RDMA READ reques

IB/hfi1: Increment the retry timeout value for TID RDMA READ request

The RC retry timeout value is based on the estimated time for the
response packet to come back. However, for TID RDMA READ request, due
to the use of header suppression, the driver is normally not notified
for each incoming response packet until the last TID RDMA READ response
packet. Consequently, the retry timeout value should be extended to
cover the transaction time for the entire length of a segment (default
256K) instead of that for a single packet. This patch addresses the
issue by introducing new retry timer functions to account for multiple
packets and wrapper functions for backward compatibility.

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>

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IB/hfi1: TID RDMA RcvArray programming and TID allocation

TID entries are used by hfi1 hardware to receive data payload from
incoming packets directly into a user buffer and thus avoid data copying

IB/hfi1: TID RDMA RcvArray programming and TID allocation

TID entries are used by hfi1 hardware to receive data payload from
incoming packets directly into a user buffer and thus avoid data copying
by software. This patch implements the functions for TID allocation,
freeing, and programming TID RcvArray entries in hardware for kernel
clients. TID entries are managed via lists of TID groups similar to PSM.
Furthermore, to track TID resource allocation for each request, software
flows are also allocated and freed as needed. Since software flows
consume large amount of memory for tracking TID allocation and freeing,
it is generally desirable to allocate them dynamically in the send queue
and only for TID RDMA requests, but pre-allocate them for receive queue
because the send queue could have thousands of entries while the receive
queue has only a limited number of entries.

Signed-off-by: Mitko Haralanov <mitko.haralanov@intel.com>
Signed-off-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
Signed-off-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>

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IB/hfi: Move RC functions into a header file

This patch moves some RC helper functions into a header file so that
they can be called from both RC and TID RDMA functions. In addition,
a common funct

IB/hfi: Move RC functions into a header file

This patch moves some RC helper functions into a header file so that
they can be called from both RC and TID RDMA functions. In addition,
a common function for rewinding a request is created in rdmavt so that
it can be shared between qib and hfi1 driver.

Reviewed-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Mitko Haralanov <mitko.haralanov@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>

show more ...