__subn_get_opa_portinfo stores value returned by hfi1_get_ib_cfg() as
operational vls. hfi1_get_ib_cfg() returns vls_operational field in
hfi1_pportdata. The problem with this is that the value is always equal
to vls_supported field in hfi1_pportdata.
The logic to calculate operational_vls is to set value passed by FM
(in __subn_set_opa_portinfo routine). If no value is passed then
default value is stored in operational_vls.
Field actual_vls_operational is calculated on the basis of buffer
control table. Hence, modifying hfi1_get_ib_cfg() to return
actual_operational_vls when used with HFI1_IB_CFG_OP_VLS parameter
Reviewed-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Reviewed-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Patel Jay P <jay.p.patel@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
The handler for link init state (HLS_UP_INIT) notifies userspace
(update_statusp()) before enabling the device
(RCV_CTRL_RCV_PORT_ENABLE_SMASK) or setting the device state
(ppd->host_link_state). This causes a race condition where the
userspace thinks the interface is in the INIT state before the driver
has set that state.
Rework the code path to eliminate the race.
Delay setting the init state until after a HW settling period.
Reviewed-by: Sebastian Sanchez <sebastian.sanchez@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>
When host is shutting down, it invokes the shutdown hook of the
L2 driver where it would attempt to free the MSI-X vectors, but would fail
because some vectors are held by the RoCE driver.
Implement the new hook in the L2 -> RoCE interface which will be invoked so that
the RoCE driver can unregister the device and free up the MSI-X vectors it had
claimed so that L2 can proceed with it's shutdown without failure.
Signed-off-by: Somnath Kotur <somnath.kotur@broadcom.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
The scqe.stag is actually __b32, fix it.
drivers/infiniband/hw/cxgb4/cq.c:754:52: warning: cast to restricted __be32
Cc: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Reviewed-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
In preparation for unconditionally passing the struct timer_list pointer to
all timer callbacks, switch to using the new timer_setup() and from_timer()
to pass the timer pointer explicitly.
Cc: Moni Shoua <monis@mellanox.com>
Cc: Doug Ledford <dledford@redhat.com>
Cc: Sean Hefty <sean.hefty@intel.com>
Cc: Hal Rosenstock <hal.rosenstock@gmail.com>
Cc: linux-rdma@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Doug Ledford <dledford@redhat.com>
In recent code, two path record entries are alwasy cleared while
allocated could be either one or two path record entries.
This leads to zero out of unallocated memory.
This fix initializes alternative path record only when alternative path
is set.
While we are at it, path record allocation doesn't check for OPA
alternative path, but rest of the code checks for OPA alternative path.
Path record allocation code doesn't check for OPA alternative LID.
This can further lead to memory corruption when only one path record is
allocated, but there is actually alternative OPA path record present in CM
request.
Cc: <stable@vger.kernel.org> # v4.12+
Fixes: 9fdca4da4d ("IB/SA: Split struct sa_path_rec based on IB and ROCE specific fields")
Signed-off-by: Parav Pandit <parav@mellanox.com>
Reviewed-by: Moni Shoua <monis@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Some user space application would like to do RSS on the inner
packet fields instead on the outer.
When MLX5_RX_HASH_INNER is set with one or more of the other
hash fields, then the RSS will be done using the inner packet.
Signed-off-by: Maor Gottlieb <maorg@mellanox.com>
Reviewed-by: Mark Bloch <markb@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Doug Ledford <dledford@redhat.com>
The device can support receive Stateless Offloads for the inner
packet's fields only when the packet is processed by TIR which is
enabled to support tunneling. Otherwise, the device treats the
packet as an ordinary non-tunneling packet and receive offloads
can be done only for the outer packet's field.
In order to enable receive Stateless Offloading support for incoming
tunneling traffic the TIR should be created with tunneled_offload_en.
Tunneling offloads is supported only be raw ethernet QP.
This patch includes:
* New QP creation flag for tunneling offloads.
* Reports device capabilities.
Signed-off-by: Maor Gottlieb <maorg@mellanox.com>
Reviewed-by: Mark Bloch <markb@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Doug Ledford <dledford@redhat.com>
In some benchmarks and some CPU architectures, writing the CQE on a full
cache line size improves performance by saving memory access operations
(read-modify-write) relative to partial cache line change. This patch
lets the user to configure the device to pad the CQE up to 128B in case
its content is less than 128B. Currently the driver supports only padding
for a CQE size of 128B.
Signed-off-by: Guy Levi <guyle@mellanox.com>
Reviewed-by: Mark Bloch <markb@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Doug Ledford <dledford@redhat.com>
In commit 1cbe6fc86c ("IB/mlx5: Add support for CQE compressing") the
concept of CQE compression was introduced and added a support for 64B
CQE size. This change update the code to support 128B CQE size as well.
Signed-off-by: Guy Levi <guyle@mellanox.com>
Reviewed-by: Mark Bloch <markb@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Allow creation of a multi-packet receive queue.
In order to create a multi-packet RQ, the following fields in
the mlx5_ib_rwq should be set:
- log_num_strides: Log of number of strides per WQE
- single_stride_log_num_of_bytes: Log of a single stride size
- two_byte_shift_en: When enabled, hardware pads 2 bytes of zeros
before writing the message to memory (e.g. for the IP alignment).
Signed-off-by: Noa Osherovich <noaos@mellanox.com>
Reviewed-by: Majd Dibbiny <majd@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Doug Ledford <dledford@redhat.com>
This patch reports the device's striding RQ capabilities to
the user-space:
- min/max_single_stride_log_num_of_bytes: Log of min/max number of
bytes in a single stride.
- min/max_single_wqe_log_num_of_strides: Log of min/max number of
strides in a single WQE.
- supported_qpts: A bit mask to know which QP types support multi-
packet RQ, for now only Raw Packet QPs.
Signed-off-by: Noa Osherovich <noaos@mellanox.com>
Reviewed-by: Majd Dibbiny <majd@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Doug Ledford <dledford@redhat.com>
It is needed to call modify cq API for modifying cq
context fields for controlling event generation
moderations. This patch mainly adds it.
Signed-off-by: Lijun Ou <oulijun@huawei.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
This patch updates the PD specification to 16M for hip08. And it
updates the numbers of mtt and cqe segments for the buddy.
As the CQE supports hop num 1 addressing, the CQE specification is
64k. This patch updates to set the CQE specification to 64k.
Signed-off-by: Shaobo Xu <xushaobo2@huawei.com>
Signed-off-by: Wei Hu (Xavier) <xavier.huwei@huawei.com>
Signed-off-by: Lijun Ou <oulijun@huawei.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
As the increase of the IRRL specification in hip08, the IRRL table
chunk size needs to be updated.
This patch updates the IRRL table chunk size to 256k for hip08.
Signed-off-by: Wei Hu (Xavier) <xavier.huwei@huawei.com>
Signed-off-by: Shaobo Xu <xushaobo2@huawei.com>
Signed-off-by: Lijun Ou <oulijun@huawei.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
This patch updates to support WQE, CQE and PBL page size configurable
feature, which includes base address page size and buffer page size.
Signed-off-by: Shaobo Xu <xushaobo2@huawei.com>
Signed-off-by: Wei Hu (Xavier) <xavier.huwei@huawei.com>
Signed-off-by: Lijun Ou <oulijun@huawei.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
NAPI budget is 64 packets, while maximum polling size for
the send CQ is 16. Let's bring them in sync, so the NAPI
budget will be reused completely.
Cc: Kamal Heib <kamalh@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: Doug Ledford <dledford@redhat.com>
Instead of explicit call to poll_cq of the tx ring, use the NAPI mechanism
to handle the completions of each packet that has been sent to the HW.
The next major changes were taken:
* The driver init completion function in the creation of the send CQ,
that function triggers the napi scheduling.
* The driver uses CQ for RX for both modes UD and CM, and CQ for TX
for CM and UD.
Cc: Kamal Heib <kamalh@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: Doug Ledford <dledford@redhat.com>
The first step toward using NAPI in the UD/TX flow is to separate
between two flows, the NAPI and the xmit, meaning no use of shared
variables between both flows.
This patch takes out the tx_outstanding variable that was used in both
flows and instead the driver uses the 2 cyclic ring variables: tx_head
and tx_tail, tx_head used in the xmit flow and tx_tail in the NAPI flow.
Cc: Kamal Heib <kamalh@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: Doug Ledford <dledford@redhat.com>
Control QP (CQP) command backlog list is initialized at
device initialization time. It is not reinitialized in
the reset flow. Move the initialization to CQP creation
time so the list can be initialized correctly for reset as well.
Fixes: 86dbcd0f12 ("i40iw: add file to handle cqp calls")
Signed-off-by: Bob Sharp <Robert.O.Sharp@intel.com>
Signed-off-by: Shiraz Saleem <shiraz.saleem@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
If User-space Direct Access (UDA) QP creation fails,
the QP entry is not removed from QoS list. Fix this
by removing QP from QoS list if create QP fails.
Fixes: 0fc2dc5889 ("i40iw: Add Quality of Service support")
Signed-off-by: Ivan Barrera <ivan.d.barrera@intel.com>
Signed-off-by: Shiraz Saleem <shiraz.saleem@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Clear Control Queue Pair (CQP) Head/Tail on CQP
initialization as during an adapter reset, these
values are not reinitialized. Tail is cleared by
writing 0 to CQP's tail register. Head is cleared
by writing 0 to CQP's doorbell register.
Fixes: 86dbcd0f12 ("i40iw: add file to handle cqp calls")
Signed-off-by: Christopher Bednarz <christopher.n.bednarz@intel.com>
Signed-off-by: Shiraz Saleem <shiraz.saleem@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Queue depth calculations use a mix of work requests
and actual number of bytes. Consolidate all calculations
using minimum WQE size to avoid confusion.
Signed-off-by: Shiraz Saleem <shiraz.saleem@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
On a netdev MTU change event, the iWARP
Exception Queue (IEQ) buffers may not be
sized properly to handle the new MTU.
Reinitialize the IEQ with new MTU size on MTU
change event.
Also, add define for the max ethernet frame size
field in IEQ QP context instead of the snd_mss
define which is for iWARP QPs' MSS field.
Signed-off-by: Shiraz Saleem <shiraz.saleem@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Completion Event Queues are created and destroyed on
a per device basis as opposed to per User-space Direct
Access resource.
Move ceq_valid to the correct place in i40iw_sc_dev
from i40iw_puda_rsrc.
Signed-off-by: Shiraz Saleem <shiraz.saleem@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
The IPv6 header size is not subtracted from MTU when MSS is
set for QPs.
Save MTU opposed to MSS in the vsi struct during
initialization and calculate the MSS based on IPv4 vs
IPv6 connection.
Fixes: f27b4746f3 ("i40iw: add connection management code")
Signed-off-by: Shiraz Saleem <shiraz.saleem@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Some structures for post SQ operation are not used.
Remove the following:
i40iw_post_send_w_inv
i40iw_post_inline_send_w_inv
send_w_sol
send_w_inv
send_w_sol_inv
inline_send_w_sol
inline_send_w_inv
inline_send_w_sol_inv
Signed-off-by: Mustafa Ismail <mustafa.ismail@intel.com>
Signed-off-by: Shiraz Saleem <shiraz.saleem@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Consolidate exception_lan_queue under VSI structure
where it belongs. Remove it from device and QP structures.
Signed-off-by: Mustafa Ismail <mustafa.ismail@intel.com>
Signed-off-by: Shiraz Saleem <shiraz.saleem@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
The field static_rsrc in i40iw_create_qp_info is unused
and not needed. Remove it.
Signed-off-by: Mustafa Ismail <mustafa.ismail@intel.com>
Signed-off-by: Shiraz Saleem <shiraz.saleem@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
The AE source field in Asynchronous Event Queue Entry (AEQE) is
not set by the hardware for some AEs, but the code assumes it does.
This results in incorrect processing of some AEs.
Fix this by setting ae_src to I40IW_AE_SOURCE_RSVD for those AEs.
Fixes: 86dbcd0f12 ("i40iw: add file to handle cqp calls")
Signed-off-by: Mustafa Ismail <mustafa.ismail@intel.com>
Signed-off-by: Shiraz Saleem <shiraz.saleem@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Conflicts:
drivers/infiniband/hw/cxgb4/cm.c
drivers/infiniband/hw/qib/qib_driver.c
drivers/infiniband/hw/qib/qib_mad.c
There were minor fixups needed in these files. Just minor context diffs
due to patches from independent sources touching the same basic area.
Signed-off-by: Doug Ledford <dledford@redhat.com>
The early for-next branch was based on v4.14-rc2, while the shared pull
request I got from Mellanox used a v4.14-rc4 base. I'm making the
branch that was the shared Mellanox pull request the new for-next branch
and merging the early for-next branch into it.
Signed-off-by: Doug Ledford <dledford@redhat.com>
Using the ARRAY_SIZE macro improves the readability of the code.
Found with Coccinelle with the following semantic patch:
@r depends on (org || report)@
type T;
T[] E;
position p;
@@
(
(sizeof(E)@p /sizeof(*E))
|
(sizeof(E)@p /sizeof(E[...]))
|
(sizeof(E)@p /sizeof(T))
)
Signed-off-by: Jérémy Lefaure <jeremy.lefaure@lse.epita.fr>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Doug Ledford <dledford@redhat.com>
The IB/core provides address resolution service and invokes callback
handler when address resolve request completes of requester in worker
thread context.
Such caller might allocate or free memory in callback handler
depending on the completion status to make further progress or to
terminate a connection. Most ULPs resolve route which involves
allocating route entry and path record elements in callback event handler.
It has been noticed that WQ_MEM_RECLAIM flag should not be used for
workers that tend to allocate memory in this [1] thread discussion.
In order to mitigate this situation, WQ_MEM_RECLAIM flag was dropped for
other such WQs in this [2] patch.
Similar problem might arise with address resolution path, though its not
yet noticed. The ib_addr workqueue is not memory reclaim path due to its
nature of invoking callback that might allocate memory or don't free any
memory under memory pressure.
[1] https://www.spinics.net/lists/linux-rdma/msg53239.html
[2] https://www.spinics.net/lists/linux-rdma/msg53416.html
Fixes: f54816261c ("IB/addr: Remove deprecated create_singlethread_workqueue")
Fixes: 5fff41e1f8 ("IB/core: Fix race condition in resolving IP to MAC")
Signed-off-by: Parav Pandit <parav@mellanox.com>
Reviewed-by: Daniel Jurgens <danielj@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Doug Ledford <dledford@redhat.com>
This patch fixes the case where 'lifespan' entry of the hw_counters
is not writable. Currently write callback is not exposed for for
the hw_counters sysfs operation. Due to this, modifying lifespan
value results into permission denied error in below example.
echo 10 > /sys/class/infiniband/mlx5_0/ports/1/hw_counters/lifespan
-bash: /sys/class/infiniband/mlx5_0/ports/1/hw_counters/lifespan:
Permission denied
This patch adds the hook to modify any attribute which implements
store() operation.
Fixes: b40f4757da ("IB/core: Make device counter infrastructure dynamic")
Signed-off-by: Parav Pandit <parav@mellanox.com>
Reviewed-by: Mark Bloch <markb@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Since IB/core resolves the destination mac address for user and kernel
consumers, avoid resolving in multiple provider drivers.
Only ib_core resolves DMAC now, therefore resolve_eth_dmac is removed as
exported symbol.
Signed-off-by: Parav Pandit <parav@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Introduce rdma_create_user_ah API which allows passing udata to
provider driver and additionally which resolves DMAC for RoCE.
ib_resolve_eth_dmac() resolves destination mac address for unicast,
multicast, link local ipv4 mapped ipv6 and ipv6 destination gid entry.
This allows all RoCE provider drivers to avoid duplicating such code.
Such change brings consistency where IB core always resolves dmac and pass
it to RoCE provider drivers for user and kernel consumers, with this
ah_attr->roce.dmac is always an input field for provider drivers.
This uniformity avoids exporting ib_resolve_eth_dmac symbol to providers
or other modules. Therefore its removed as exported symbol at later in
the patch series.
Now uverbs and umad both makes use of rdma_create_user_ah API which
fixes the issue where umad has invalid DMAC for address.
Signed-off-by: Parav Pandit <parav@mellanox.com>
Reviewed-by: Daniel Jurgens <danielj@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Doug Ledford <dledford@redhat.com>
In preparation for unconditionally passing the struct timer_list pointer to
all timer callbacks, switch to using the new timer_setup() and from_timer()
to pass the timer pointer explicitly. Also removes an unused timer and
drops a redundant initialization.
Cc: Steve Wise <swise@chelsio.com>
Cc: Doug Ledford <dledford@redhat.com>
Cc: Sean Hefty <sean.hefty@intel.com>
Cc: Hal Rosenstock <hal.rosenstock@gmail.com>
Cc: linux-rdma@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
In preparation for unconditionally passing the struct timer_list pointer to
all timer callbacks, switch to using the new timer_setup() and from_timer()
to pass the timer pointer explicitly.
This includes the remaining timers missed in the earlier i40iw patch.
Cc: Faisal Latif <faisal.latif@intel.com>
Cc: Shiraz Saleem <shiraz.saleem@intel.com>
Cc: Doug Ledford <dledford@redhat.com>
Cc: Sean Hefty <sean.hefty@intel.com>
Cc: Hal Rosenstock <hal.rosenstock@gmail.com>
Cc: linux-rdma@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Doug Ledford <dledford@redhat.com>
In preparation for unconditionally passing the struct timer_list pointer to
all timer callbacks, switch to using the new timer_setup() and from_timer()
to pass the timer pointer explicitly. Also removes an unused timer.
Cc: Steve Wise <swise@chelsio.com>
Cc: Doug Ledford <dledford@redhat.com>
Cc: Sean Hefty <sean.hefty@intel.com>
Cc: Hal Rosenstock <hal.rosenstock@gmail.com>
Cc: linux-rdma@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
In preparation for unconditionally passing the struct timer_list pointer to
all timer callbacks, switch to using the new timer_setup() and from_timer()
to pass the timer pointer explicitly. Switches test of .data field to
.function, since .data will be going away.
Cc: Mike Marciniszyn <mike.marciniszyn@intel.com>
Cc: Dennis Dalessandro <dennis.dalessandro@intel.com>
Cc: Doug Ledford <dledford@redhat.com>
Cc: Sean Hefty <sean.hefty@intel.com>
Cc: Hal Rosenstock <hal.rosenstock@gmail.com>
Cc: linux-rdma@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Doug Ledford <dledford@redhat.com>
In preparation for unconditionally passing the struct timer_list pointer to
all timer callbacks, switch to using the new timer_setup() and from_timer()
to pass the timer pointer explicitly.
setup_timer() was already being called before the open-coded init_timer()
and .data assignment. These are removed as well.
Cc: Dennis Dalessandro <dennis.dalessandro@intel.com>
Cc: Doug Ledford <dledford@redhat.com>
Cc: Sean Hefty <sean.hefty@intel.com>
Cc: Hal Rosenstock <hal.rosenstock@gmail.com>
Cc: linux-rdma@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Doug Ledford <dledford@redhat.com>
For small networks it is safe to reduce the subnet timeout from
its default value (18 for opensm) to 16. Make the SRP CM timeout
dependent on the subnet timeout such that decreasing the subnet
timeout also causes SRP failover and failback to occur faster.
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Doug Ledford <dledford@redhat.com>
This is a micro-optimization for the hot path.
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
This patch does not change any functionality.
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Although in the RC mode more resources are needed that mode has three
advantages over SRQ:
- It works with all RDMA adapters, even those that do not support
SRQ.
- Posting WRs and polling WCs does not trigger lock contention
because only one thread at a time accesses a WR or WC queue in
non-SRQ mode.
- The end-to-end flow control mechanism is used.
>From the IB spec:
C9-150.2.1: For QPs that are not associated with an SRQ, each HCA
receive queue shall generate end-to-end flow control credits. If
a QP is associated with an SRQ, the HCA receive queue shall not
generate end-to-end flow control credits.
Add new configfs attributes that allow to configure which mode to use
(/sys/kernel/config/target/srpt/$GUID/$GUID/attrib/use_srq). Note:
only the attribute for port 1 is relevant on multi-port adapters.
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
This patch is a micro-optimization for the hot path.
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
