ntb: no sleep in ntb_async_tx_submit

Do not sleep in ntb_async_tx_submit, which could deadlock.
This reverts commit "8c874cc140d667f84ae4642bb5b5e0d6396d2ca4"

Fixes: 8c874cc140d6 ("NTB: Address out

ntb: no sleep in ntb_async_tx_submit

Do not sleep in ntb_async_tx_submit, which could deadlock.
This reverts commit "8c874cc140d667f84ae4642bb5b5e0d6396d2ca4"

Fixes: 8c874cc140d6 ("NTB: Address out of DMA descriptor issue with NTB")
Reported-by: Jia-Ju Bai <baijiaju1990@163.com>
Signed-off-by: Allen Hubbe <Allen.Hubbe@dell.com>
Acked-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

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ntb_transport: fix bug calculating num_qps_mw

A divide by zero error occurs if qp_count is less than mw_count because
num_qps_mw is calculated to be zero. The calculation appears to be
incorrect.

T

ntb_transport: fix bug calculating num_qps_mw

A divide by zero error occurs if qp_count is less than mw_count because
num_qps_mw is calculated to be zero. The calculation appears to be
incorrect.

The requirement is for num_qps_mw to be set to qp_count / mw_count
with any remainder divided among the earlier mws.

For example, if mw_count is 5 and qp_count is 12 then mws 0 and 1
will have 3 qps per window and mws 2 through 4 will have 2 qps per window.
Thus, when mw_num < qp_count % mw_count, num_qps_mw is 1 higher
than when mw_num >= qp_count.

Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Fixes: e26a5843f7f5 ("NTB: Split ntb_hw_intel and ntb_transport drivers")
Acked-by: Allen Hubbe <Allen.Hubbe@dell.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

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ntb_transport: fix qp count bug

In cases where there are more mw's than spads/2-2, the mw count gets
reduced to match the limitation. ntb_transport also tries to ensure that
there are fewer qps than

ntb_transport: fix qp count bug

In cases where there are more mw's than spads/2-2, the mw count gets
reduced to match the limitation. ntb_transport also tries to ensure that
there are fewer qps than mws but uses the full mw count instead of
the reduced one. When this happens, the math in
'ntb_transport_setup_qp_mw' will get confused and result in a kernel
paging request bug.

This patch fixes the bug by reducing qp_count to the reduced mw count
instead of the full mw count.

Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Fixes: e26a5843f7f5 ("NTB: Split ntb_hw_intel and ntb_transport drivers")
Acked-by: Allen Hubbe <Allen.Hubbe@dell.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

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ntb_transport: Pick an unused queue

Fix typo causing ntb_transport_create_queue to select the first
queue every time, instead of using the next free queue.

Signed-off-by: Thomas VanSelus <tvanselus

ntb_transport: Pick an unused queue

Fix typo causing ntb_transport_create_queue to select the first
queue every time, instead of using the next free queue.

Signed-off-by: Thomas VanSelus <tvanselus@xes-inc.com>
Signed-off-by: Aaron Sierra <asierra@xes-inc.com>
Acked-by: Allen Hubbe <Allen.Hubbe@dell.com>
Fixes: fce8a7bb5 ("PCI-Express Non-Transparent Bridge Support")
Signed-off-by: Jon Mason <jdmason@kudzu.us>

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NTB: ntb_transport: fix debugfs_remove_recursive

The call to debugfs_remove_recursive(qp->debugfs_dir) of the sub-level
directory must not be later than
debugfs_remove_recursive(nt_debugfs_dir) of t

NTB: ntb_transport: fix debugfs_remove_recursive

The call to debugfs_remove_recursive(qp->debugfs_dir) of the sub-level
directory must not be later than
debugfs_remove_recursive(nt_debugfs_dir) of the top-level directory.
Otherwise, the sub-level directory will not exist, and it would be
invalid (panic) to attempt to remove it. This removes the top-level
directory last, after sub-level directories have been cleaned up.

Signed-off-by: Allen Hubbe <Allen.Hubbe@dell.com>
Fixes: e26a5843f ("NTB: Split ntb_hw_intel and ntb_transport drivers")
Signed-off-by: Jon Mason <jdmason@kudzu.us>

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ntb_transport: Remove unnecessary call to ntb_peer_spad_read

The results were previously ignored, anyway.

Signed-off-by: Steve Wahl <Steve.Wahl@dell.com>
Fixes: e26a5843f7f5014ae4460030ca4de029a3ac

ntb_transport: Remove unnecessary call to ntb_peer_spad_read

The results were previously ignored, anyway.

Signed-off-by: Steve Wahl <Steve.Wahl@dell.com>
Fixes: e26a5843f7f5014ae4460030ca4de029a3ac35d3
Acked-by: Allen Hubbe <Allen.Hubbe@dell.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

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ntb_transport: Limit memory windows based on available, scratchpads

When the underlying NTB H/W driver advertises more memory windows
than the number of scratchpads available to setup MW's, it is li

ntb_transport: Limit memory windows based on available, scratchpads

When the underlying NTB H/W driver advertises more memory windows
than the number of scratchpads available to setup MW's, it is likely
that we may end up filling the remaining memory windows with garbage.
So to avoid that, lets limit the memory windows that transport driver
can setup based on the available scratchpads.

Signed-off-by: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
Acked-by: Allen Hubbe <Allen.Hubbe@dell.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

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ntb_transport: make DMA_OUT_RESOURCE_TO HZ independent

schedule_timeout_* takes a timeout in jiffies but the code currently is
passing in a constant which makes this timeout HZ dependent, so pass it

ntb_transport: make DMA_OUT_RESOURCE_TO HZ independent

schedule_timeout_* takes a timeout in jiffies but the code currently is
passing in a constant which makes this timeout HZ dependent, so pass it
through msecs_to_jiffies() to fix this up.

Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

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ntb: add DMA error handling for RX DMA

Adding support on the rx DMA path to allow recovery of errors when
DMA responds with error status and abort all the subsequent ops.

Signed-off-by: Dave Jiang

ntb: add DMA error handling for RX DMA

Adding support on the rx DMA path to allow recovery of errors when
DMA responds with error status and abort all the subsequent ops.

Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Acked-by: Allen Hubbe <Allen.Hubbe@emc.com>
Cc: Jon Mason <jdmason@kudzu.us>
Cc: linux-ntb@googlegroups.com
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

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ntb: add DMA error handling for TX DMA

Adding support on the tx DMA path to allow recovery of errors when
DMA responds with error status and abort all the subsequent ops.

Signed-off-by: Dave Jiang

ntb: add DMA error handling for TX DMA

Adding support on the tx DMA path to allow recovery of errors when
DMA responds with error status and abort all the subsequent ops.

Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Acked-by: Allen Hubbe <Allen.Hubbe@emc.com>
Cc: Jon Mason <jdmason@kudzu.us>
Cc: linux-ntb@googlegroups.com
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

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ntb_transport: Check the number of spads the hardware supports

I'm working on hardware that currently has a limited number of
scratchpad registers and ntb_ndev fails with no clue as to why. I
feel i

ntb_transport: Check the number of spads the hardware supports

I'm working on hardware that currently has a limited number of
scratchpad registers and ntb_ndev fails with no clue as to why. I
feel it is better to fail early and provide a reasonable error message
then to fail later on.

The same is done to ntb_perf, but it doesn't currently require enough
spads to actually fail. I've also removed the unused SPAD_MSG and
SPAD_ACK enums so that MAX_SPAD accurately reflects the number of
spads used.

Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Acked-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

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NTB: allocate number transport entries depending on size of ring size

Currently we only allocate a fixed default number of descriptors for the tx
and rx side. We should dynamically resize it to the

NTB: allocate number transport entries depending on size of ring size

Currently we only allocate a fixed default number of descriptors for the tx
and rx side. We should dynamically resize it to the number of descriptors
resides in the transport rings. We should know the number of transmit
descriptors at initializaiton. We will allocate the default number of
descriptors for receive side and allocate additional ones when we know the
actual max entries for receive.

Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Acked-by: Allen Hubbe <allen.hubbe@emc.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

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ntb: stop link work when we do not have memory

Instead of keep trying to go through the init routine when we aren't able
to allocate memory, we should just stop and go down.

Signed-off-by: Dave Jia

ntb: stop link work when we do not have memory

Instead of keep trying to go through the init routine when we aren't able
to allocate memory, we should just stop and go down.

Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

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ntb: stop tasklet from spinning forever during shutdown.

We can leave tasklet spinning forever if we disable the tasklet during
qp shutdown and the tasklets are still being kicked off. This hopefull

ntb: stop tasklet from spinning forever during shutdown.

We can leave tasklet spinning forever if we disable the tasklet during
qp shutdown and the tasklets are still being kicked off. This hopefully
should avoid that race condition.

Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Reported-by: Alex Depoutovitch <alex@pernixdata.com>
Tested-by: Alex Depoutovitch <alex@pernixdata.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

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NTB: Address out of DMA descriptor issue with NTB

The transport right now does not handle the case where we run out of DMA
descriptors. We just fail when we do not succeed. Adding code to retry for

NTB: Address out of DMA descriptor issue with NTB

The transport right now does not handle the case where we run out of DMA
descriptors. We just fail when we do not succeed. Adding code to retry for
a bit attempting to use the DMA engine instead of instantly fail to CPU
copy.

Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Allen Hubbe <Allen.Hubbe@emc.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

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NTB: ntb_process_tx error path bug

The transmit overrun avoidance error path in ntb_process_tx accidentally
swapped the first two values being passed to the tx_handler client.
This could result in c

NTB: ntb_process_tx error path bug

The transmit overrun avoidance error path in ntb_process_tx accidentally
swapped the first two values being passed to the tx_handler client.
This could result in crashes in the ntb_netdev (or other out-of-tree NTB
clients).

Reported-by: Alex Depoutovitch <alex@pernixdata.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

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NTB: fix 32-bit compiler warning

resource_size_t may be 32-bit wide on some architectures, which causes
this warning when building the NTB code:

drivers/ntb/ntb_transport.c: In function 'ntb_transp

NTB: fix 32-bit compiler warning

resource_size_t may be 32-bit wide on some architectures, which causes
this warning when building the NTB code:

drivers/ntb/ntb_transport.c: In function 'ntb_transport_link_work':
drivers/ntb/ntb_transport.c:828:46: warning: right shift count >= width of type [-Wshift-count-overflow]

The warning is harmless but can be avoided by using the upper_32_bits()
macro.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: e26a5843f7f5 ("NTB: Split ntb_hw_intel and ntb_transport drivers")
Signed-off-by: Jon Mason <jdmason@kudzu.us>

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NTB: invalid buf pointer in multi-MW setups

Order of operations issue with the QP Num and MW count, which would
result in the receive buffer pointer being invalid if there are more
than 1 MW. Corre

NTB: invalid buf pointer in multi-MW setups

Order of operations issue with the QP Num and MW count, which would
result in the receive buffer pointer being invalid if there are more
than 1 MW. Corrected with parenthesis to enforce the proper order of
operations.

Reported-by: John I. Kading <John.Kading@gd-ms.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

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NTB: remove unused variable

These variables were not used anywhere. So remove them.

Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

NTB: fix access of free-ed pointer

We were accessing nt->mw_vec after freeing it. Fix the error path so
that we free nt->mw_vec after we have finished using it.

Signed-off-by: Sudip Mukherjee <sudi

NTB: fix access of free-ed pointer

We were accessing nt->mw_vec after freeing it. Fix the error path so
that we free nt->mw_vec after we have finished using it.

Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

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NTB: Fix issue where we may be accessing NULL ptr

smatch detected an issue in the function ntb_transport_max_size() where
we could be dereferencing a dma channel pointer when it is NULL.

Reported-b

NTB: Fix issue where we may be accessing NULL ptr

smatch detected an issue in the function ntb_transport_max_size() where
we could be dereferencing a dma channel pointer when it is NULL.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

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NTB: Use unique DMA channels for TX and RX

Allocate two DMA channels, one for TX operation and one for RX
operation, instead of having one DMA channel for everything. This
provides slightly better p

NTB: Use unique DMA channels for TX and RX

Allocate two DMA channels, one for TX operation and one for RX
operation, instead of having one DMA channel for everything. This
provides slightly better performance, and also will make error handling
cleaner later on.

Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

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NTB: Remove dma_sync_wait from ntb_async_rx

The dma_sync_wait can hurt the performance of workloads mixed with both
large and small frames. Large frames will be copied using the dma
engine. Small

NTB: Remove dma_sync_wait from ntb_async_rx

The dma_sync_wait can hurt the performance of workloads mixed with both
large and small frames. Large frames will be copied using the dma
engine. Small frames will be copied by the cpu. The dma_sync_wait
prevents the cpu and dma engine copying in parallel.

In the period where the cpu is copying, the dma engine is stopped. The
dma engine is not doing any useful work to copy large frames during that
time, and the additional time to restart the dma engine for the next
large frame. This will decrease the throughput for the portion of a
workload with large frames.

In the period where the dma engine is copying, the cpu is held up
waiting for dma to complete. The small frames processing will be
delayed until the dma is complete. The RX frames are completed
in-order, and the processing of small frames takes very little time, so
dma_sync_wait may have an insignificant impact on the respose time of
frames. The more significant impact is to the system, because the delay
in dma_sync_wait is implemented as busy non-blocking wait. This can
prevent the delayed core from doing any useful work, even if it could be
processing work for other drivers, unrelated to transport RX processing.

After applying the earlier patch to fix out-of-order RX acknoledgement,
the dma_sync_wait is no longer necessary. Remove it, so that cpu memcpy
will proceed immediately for small frames, in parallel with ongoing dma
for large frames. Do not hold up the cpu from doing work while dma is
in progress. The prior fix will continue to ensure in-order completion
of the RX frames to the upper layer, and in-order delivery of the RX
acknoledgement.

Signed-off-by: Allen Hubbe <Allen.Hubbe@emc.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

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NTB: Clean up QP stats info

Make QP stats info more readable for debugging purposes. Also add an
entry to indicate whether DMA is being used.

Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Signe

NTB: Clean up QP stats info

Make QP stats info more readable for debugging purposes. Also add an
entry to indicate whether DMA is being used.

Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

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NTB: Make the transport list in order of discovery

The list should be added from the bottom and not the top in order to
ensure the transport is provided in the same order to clients as ntb
devices a

NTB: Make the transport list in order of discovery

The list should be added from the bottom and not the top in order to
ensure the transport is provided in the same order to clients as ntb
devices are discovered.

Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

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