NTB: Add flow control to the ntb_netdev

Right now if we push the NTB really hard, we start dropping packets due
to not able to process the packets fast enough. We need to st:qop the
upper layer from

NTB: Add flow control to the ntb_netdev

Right now if we push the NTB really hard, we start dropping packets due
to not able to process the packets fast enough. We need to st:qop the
upper layer from flooding us when that happens.

A timer is necessary in order to restart the queue once the resource has
been processed on the receive side. Due to the way NTB is setup, the
resources on the tx side are tied to the processing of the rx side and
there's no async way to know when the rx side has released those
resources.

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

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NTB: Fix dereference before check

Remove early dereference of a pointer that is checked later in the code.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Allen Hubbe <Allen.Hu

NTB: Fix dereference before check

Remove early dereference of a pointer that is checked later in the code.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Allen Hubbe <Allen.Hubbe@emc.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

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NTB: Fix zero size or integer overflow in ntb_set_mw

A plain 32 bit integer will overflow for values over 4GiB.

Change the plain integer size to the appropriate size type in
ntb_set_mw. Change the

NTB: Fix zero size or integer overflow in ntb_set_mw

A plain 32 bit integer will overflow for values over 4GiB.

Change the plain integer size to the appropriate size type in
ntb_set_mw. Change the type of the size parameter and two local
variables used for size.

Even if there is no overflow, a size of zero is invalid here.

Reported-by: Juyoung Jung <jjung@micron.com>
Signed-off-by: Allen Hubbe <Allen.Hubbe@emc.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

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NTB: Schedule to receive on QP link up

Schedule to receive on QP link up, to make sure that the doorbell is
properly cleared for interrupts.

Signed-off-by: Allen Hubbe <Allen.Hubbe@emc.com>
Signed-

NTB: Schedule to receive on QP link up

Schedule to receive on QP link up, to make sure that the doorbell is
properly cleared for interrupts.

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

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NTB: Fix oops in debugfs when transport is half-up

When the remote side is not up, we do not have all the context for the
transport, and that causes NULL ptr access. Have the debugfs reads check
to

NTB: Fix oops in debugfs when transport is half-up

When the remote side is not up, we do not have all the context for the
transport, and that causes NULL ptr access. Have the debugfs reads check
to see if transport is up before we make access.

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

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NTB: Fix transport stats for multiple devices

Currently the debugfs does not have files for all NTB transport queue
pairs. When there are multiple NTBs present in a system, the QP names
of the last

NTB: Fix transport stats for multiple devices

Currently the debugfs does not have files for all NTB transport queue
pairs. When there are multiple NTBs present in a system, the QP names
of the last transport clobber the names of previously added transport
QPs. Only the last added QPs can be observed via debugfs.

Create a directory per NTB transport to associate the QPs with that
transport. Name the directory the same as the PCI device.

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

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NTB: Fix ntb_transport out-of-order RX update

It was possible for a synchronous update of the RX index in the error
case to get ahead of the asynchronous RX index update in the normal
case. Change

NTB: Fix ntb_transport out-of-order RX update

It was possible for a synchronous update of the RX index in the error
case to get ahead of the asynchronous RX index update in the normal
case. Change the RX processing to preserve an RX completion order.

There were two error cases. First, if a buffer is not present to
receive data, there would be no queue entry to preserve the RX
completion order. Instead of dropping the RX frame, leave the RX frame
in the ring. Schedule RX processing when RX entries are enqueued, in
case there are RX frames waiting in the ring to be received.

Second, if a buffer is too small to receive data, drop the frame in the
ring, mark the RX entry as done, and indicate the error in the RX entry
length. Check for a negative length in the receive callback in
ntb_netdev, and count occurrences as rx_length_errors.

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

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NTB: Print driver name and version in module init

Printouts driver name and version to indicate what is being loaded.

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

NTB: Print driver name and version in module init

Printouts driver name and version to indicate what is being loaded.

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

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NTB: Increase transport MTU to 64k from 16k

Benchmarking showed a significant performance increase with the MTU size
to 64k instead of 16k. Change the driver default to 64k.

Signed-off-by: Dave Ji

NTB: Increase transport MTU to 64k from 16k

Benchmarking showed a significant performance increase with the MTU size
to 64k instead of 16k. Change the driver default to 64k.

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

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NTB: Default to CPU memcpy for performance

Disable DMA usage by default, since the CPU provides much better
performance with write combining. Provide a module parameter to enable
DMA usage when off

NTB: Default to CPU memcpy for performance

Disable DMA usage by default, since the CPU provides much better
performance with write combining. Provide a module parameter to enable
DMA usage when offloading the memcpy is preferred.

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

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NTB: Improve performance with write combining

Changing the memory window BAR mappings to write combining significantly
boosts the performance. We will also use memcpy that uses non-temporal
store,

NTB: Improve performance with write combining

Changing the memory window BAR mappings to write combining significantly
boosts the performance. We will also use memcpy that uses non-temporal
store, which showed performance improvement when doing non-cached
memcpys.

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

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NTB: Use NUMA memory and DMA chan in transport

Allocate memory and request the DMA channel for the same NUMA node as
the NTB device.

Signed-off-by: Allen Hubbe <Allen.Hubbe@emc.com>
Signed-off-by:

NTB: Use NUMA memory and DMA chan in transport

Allocate memory and request the DMA channel for the same NUMA node as
the NTB device.

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

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NTB: Rate limit ntb_qp_link_work

When the ntb transport is connecting and waiting for the peer, the debug
console receives lots of debug level messages about the remote qp link
status being down. R

NTB: Rate limit ntb_qp_link_work

When the ntb transport is connecting and waiting for the peer, the debug
console receives lots of debug level messages about the remote qp link
status being down. Rate limit those messages.

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

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NTB: Reset transport QP link stats on down

Reset the link stats when the link goes down. In particular, the TX and
RX index and count must be reset, or else the TX side will be sending
packets to t

NTB: Reset transport QP link stats on down

Reset the link stats when the link goes down. In particular, the TX and
RX index and count must be reset, or else the TX side will be sending
packets to the RX side where the RX side is not expecting them. Reset
all the stats, to be consistent.

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

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NTB: Do not advance transport RX on link down

On link down, don't advance RX index to the next entry. The next entry
should never be valid after receiving the link down flag.

Signed-off-by: Allen

NTB: Do not advance transport RX on link down

On link down, don't advance RX index to the next entry. The next entry
should never be valid after receiving the link down flag.

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

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NTB: Differentiate transport link down messages

The same message "qp %d: Link Down\n" was printed at two locations in
ntb_transport. Change the messages so they are distinct.

Signed-off-by: Allen

NTB: Differentiate transport link down messages

The same message "qp %d: Link Down\n" was printed at two locations in
ntb_transport. Change the messages so they are distinct.

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

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NTB: Read peer info from local SPAD in transport

The transport was writing and then reading the peer scratch pad,
essentially reading what it just wrote instead of exchanging any
information with th

NTB: Read peer info from local SPAD in transport

The transport was writing and then reading the peer scratch pad,
essentially reading what it just wrote instead of exchanging any
information with the peer. The transport expects the peer values to be
the same as the local values, so this issue was not obvious.

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

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NTB: Split ntb_hw_intel and ntb_transport drivers

Change ntb_hw_intel to use the new NTB hardware abstraction layer.

Split ntb_transport into its own driver. Change it to use the new NTB
hardware

NTB: Split ntb_hw_intel and ntb_transport drivers

Change ntb_hw_intel to use the new NTB hardware abstraction layer.

Split ntb_transport into its own driver. Change it to use the new NTB
hardware abstraction layer.

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

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NTB: Move files in preparation for NTB abstraction

This patch only moves files to their new locations, before applying the
next two patches adding the NTB Abstraction layer. Splitting this patch
fr

NTB: Move files in preparation for NTB abstraction

This patch only moves files to their new locations, before applying the
next two patches adding the NTB Abstraction layer. Splitting this patch
from the next is intended make distinct which code is changed only due
to moving the files, versus which are substantial code changes in adding
the NTB Abstraction layer.

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

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ntb: Add alignment check to meet hardware requirement

The NTB translate register must have the value to be BAR size aligned.
This alignment check make sure that the DMA memory allocated has the
prop

ntb: Add alignment check to meet hardware requirement

The NTB translate register must have the value to be BAR size aligned.
This alignment check make sure that the DMA memory allocated has the
proper alignment. Another requirement for NTB to function properly with
memory window BAR size greater or equal to 4M is to use the CMA feature
in 3.16 kernel with the appropriate CONFIG_CMA_ALIGNMENT and
CONFIG_CMA_SIZE_MBYTES set.

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

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NTB: correct the spread of queues over mw's

The detection of an uneven number of queues on the given memory windows
was not correct. The mw_num is zero based and the mod should be
division to sprea

NTB: correct the spread of queues over mw's

The detection of an uneven number of queues on the given memory windows
was not correct. The mw_num is zero based and the mod should be
division to spread them evenly over the mw's.

Signed-off-by: Jon Mason <jon.mason@intel.com>

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NTB: Code Style Clean-up

Some white space and 80 char overruns corrected.

Signed-off-by: Jon Mason <jon.mason@intel.com>

NTB: client event cleanup

Provide a better event interface between the client and transport

Signed-off-by: Jon Mason <jon.mason@intel.com>

NTB: Disable interrupts and poll under high load

Disable interrupts and poll under high load

Signed-off-by: Jon Mason <jon.mason@intel.com>

NTB: correct dmaengine_get/put usage

dmaengine_get() causes the initialization of the per-cpu channel tables.
It needs to be called prior to dma_find_channel().

Initial version by Dan Williams <dan

NTB: correct dmaengine_get/put usage

dmaengine_get() causes the initialization of the per-cpu channel tables.
It needs to be called prior to dma_find_channel().

Initial version by Dan Williams <dan.j.williams@intel.com>

Signed-off-by: Jon Mason <jon.mason@intel.com>

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