linux-toradex.git/drivers/scsi/lpfc/lpfc.h, branch v4.16

scsi: lpfc: Fix random heartbeat timeouts during heavy IO

2017-12-21T02:11:44+00:00

NVME targets appear to randomly disconnect from the initiator when
running heavy IO.

The error is due to the host aggregate (across all controllers) io load
was beyond the maximum exchange count for nvme on the adapter. The
driver was properly returning a resource busy status, but the io load
was so great heartbeat commands would be bounced and not have a
successful retry within the fuzz amount for the nvme heartbeat (yes, a
very high io load!). Thus the target was terminating the controller due
to a keep alive failure.

Resolve by reserving a few exchanges (by counters) which can be used
when the adapter is out of normal exchanges and the command is a NVME
heartbeat command. As counters are used, while the reserved command is
outstanding, as soon as any other exchange completes, the counters are
adjusted and the reserved count is replenished. The heartbeat completes
execution in a normal fashion.

Signed-off-by: Dick Kennedy 
Signed-off-by: James Smart 
Reviewed-by: Hannes Reinecke 
Signed-off-by: Martin K. Petersen

scsi: lpfc: small sg cnt cleanup

2017-12-05T01:32:55+00:00

The logic for sg_seg_cnt is a bit convoluted. This patch tries to clean
up a couple of areas, especially around the +2 and +1 logic.

This patch:

- Cleans up the lpfc_sg_seg_cnt attribute to specify a real minimum
  rather than making the minimum be whatever the default is.

- Removes the hardcoding of +2 (for the number of elements we use in a
  sgl for cmd iu and rsp iu) and +1 (an additional entry to compensate
  for nvme's reduction of io size based on a possible partial page)
  logic in sg list initialization. In the case where the +1 logic is
  referenced in host and target io checks, use the values set in the
  transport template as that value was properly set.

There can certainly be more done in this area and it will be addressed
in combined host/target driver effort.

Signed-off-by: Dick Kennedy 
Signed-off-by: James Smart 
Reviewed-by: Hannes Reinecke 
Signed-off-by: Martin K. Petersen

scsi: lpfc: Raise maximum NVME sg list size for 256 elements

2017-12-05T01:32:54+00:00

Raise the maximum NVME sg list size allowed to 256 elements.

Signed-off-by: Dick Kennedy 
Signed-off-by: James Smart 
Reviewed-by: Hannes Reinecke 
Signed-off-by: Martin K. Petersen

scsi: lpfc: Handle XRI_ABORTED_CQE in soft IRQ

2017-12-05T01:32:53+00:00

XRI_ABORTED_CQE completions were not being handled in the fast path.
They were being queued and deferred to the lpfc worker thread for
processing. This is an artifact of the driver design prior to moving
queue processing out of the isr and into a workq element. Now that queue
processing is already in a deferred context, remove this artifact and
process them directly.

Signed-off-by: Dick Kennedy 
Signed-off-by: James Smart 
Reviewed-by: Hannes Reinecke 
Signed-off-by: Martin K. Petersen

scsi: lpfc: Move CQ processing to a soft IRQ

2017-10-03T02:46:36+00:00

Under heavy target nvme load duration, the lpfc irq handler is
encountering cpu lockup warnings.

Convert the driver to a shortened ISR handler which identifies the
interrupting condition then schedules a workq thread to process the
completion queue the interrupt was for. This moves all the real work
into the workq element.

As nvmet_fc upcalls are no longer in ISR context, don't set the feature
flags

Signed-off-by: Dick Kennedy 
Signed-off-by: James Smart 
Reviewed-by: Johannes Thumshirn 
Signed-off-by: Martin K. Petersen

scsi: lpfc: Add Buffer to Buffer credit recovery support

2017-08-25T02:29:43+00:00

Add Buffer to buffer credit recovery support to the driver.  This is a
negotiated feature with the peer that allows for both sides to detect
dropped RRDY's and FC Frames and recover credit.

Signed-off-by: Dick Kennedy 
Signed-off-by: James Smart 
Reviewed-by: Johannes Thumshirn 
Signed-off-by: Martin K. Petersen

scsi: lpfc: Replace PCI pool old API

2017-08-07T18:04:01+00:00

The PCI pool API is deprecated. This commit replaces the PCI pool old
API by the appropriate function with the DMA pool API. It also updates
some comments, accordingly.

Signed-off-by: Romain Perier 
Reviewed-by: Peter Senna Tschudin 
Signed-off-by: Martin K. Petersen

scsi: lpfc: Add auto EQ delay logic

2017-06-13T01:37:31+00:00

Administrator intervention is currently required to get good numbers
when switching from running latency tests to IOPS tests.

The configured interrupt coalescing values will greatly effect the
results of these tests.  Currently, the driver has a single coalescing
value set by values of the module attribute.  This patch changes the
driver to support auto-configuration of the coalescing value based on
the total number of outstanding IOs and average number of CQEs processed
per interrupt for an EQ.  Values are checked every 5 seconds.

The driver defaults to the automatic selection. Automatic selection can
be disabled by the new lpfc_auto_imax module_parameter.

Older hardware can only change interrupt coalescing by mailbox
command. Newer hardware supports change via a register. The patch
support both.

Signed-off-by: Dick Kennedy 
Signed-off-by: James Smart 
Signed-off-by: Martin K. Petersen

scsi: lpfc: Fix counters so outstandng NVME IO count is accurate

2017-06-13T01:37:31+00:00

NVME FC counters don't reflect actual results

Since counters are not atomic, or protected by a lock, the values often
get screwed up.

Make them atomic, like NVMET.  Fix up sysfs and debugfs display
accordingly Added Outstanding IOs to stats display

Signed-off-by: Dick Kennedy 
Signed-off-by: James Smart 
Signed-off-by: Martin K. Petersen

scsi: lpfc: Add MDS Diagnostic support.

2017-05-17T01:24:47+00:00

Added code to support Cisco MDS loopback diagnostic. The diagnostics run
various loopbacks including one which loops-back frame through the
driver.

Signed-off-by: Dick Kennedy 
Signed-off-by: James Smart 
Reviewed-by: Hannes Reinecke 
Signed-off-by: Martin K. Petersen