Currently, WriteBooster (WB) buffer is always flushed during hibern8. However,
this is inefficient because data in the WB buffer can be invalid due to
spatial locality of IO workload.
If the WB buffer flush is flushed in a batched manner, the amount of data
migration and power consumption can be reduced because the overwritten data
of the WB buffer may be invalid due to spatial locality.

This patch supports batched flush of WB buffer. When batched flush is enabled,
fWriteBoosterBufferFlushDuringHibernate is set only when
b_rpm_dev_flush_capable is true during runtime suspend. When the device is
resumed, fWriteBoosterBufferFlushDuringHibernate is cleared to stop flush
during hibern8.

Co-developed-by: Keoseong Park <keosung.park@samsung.com>
Signed-off-by: Keoseong Park <keosung.park@samsung.com>
Signed-off-by: Daejun Park <daejun7.park@samsung.com>

Fix the function name in the kernel-doc header above ft_prli().

Link: https://lore.kernel.org/r/20210415220826.29438-21-bvanassche@acm.org
Cc: Hannes Reinecke <hare@suse.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Do not print tg_pt_gp->tg_pt_gp_valid_id if we already know that it is zero.

Link: https://lore.kernel.org/r/20210415220826.29438-20-bvanassche@acm.org
Cc: Mike Christie <michael.christie@oracle.com>
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Use format specifier '%u' to format the u32 data type instead of '%hu'.

Link: https://lore.kernel.org/r/20210415220826.29438-19-bvanassche@acm.org
Cc: Mike Christie <michael.christie@oracle.com>
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Instead of leaving it implicit that SAM_STAT_GOOD == 0, compare explicitly
with SAM_STAT_GOOD.

Link: https://lore.kernel.org/r/20210415220826.29438-18-bvanassche@acm.org
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Instead of using 'retval' to represent first a SCSI status and later
whether or not a disk change event occurred, introduce a new variable for
the latter purpose.

Link: https://lore.kernel.org/r/20210415220826.29438-17-bvanassche@acm.org
Cc: Christoph Hellwig <hch@lst.de>
Cc: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

The dc395x driver is one of the two drivers that passes an u8 argument to
status_byte() instead of an s32 argument. Open-code status_byte() in
preparation of changing SCSI status values into a structure.

Link: https://lore.kernel.org/r/20210415220826.29438-16-bvanassche@acm.org
Cc: Hannes Reinecke <hare@suse.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

The 53c700 driver is one of the two drivers that passes an u8 argument to
status_byte() instead of an s32 argument. Open-code status_byte in
preparation of changing SCSI status values into a structure.

Link: https://lore.kernel.org/r/20210415220826.29438-15-bvanassche@acm.org
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

This was detected by building the kernel with clang and W=1.

Link: https://lore.kernel.org/r/20210415220826.29438-14-bvanassche@acm.org
Cc: Don Brace <don.brace@microchip.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

This was detected by building the kernel with clang and W=1.

Link: https://lore.kernel.org/r/20210415220826.29438-13-bvanassche@acm.org
Cc: Nilesh Javali <njavali@marvell.com>
Acked-by: Manish Rangankar <mrangankar@marvell.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

This was detected by building the kernel with clang and W=1.

Link: https://lore.kernel.org/r/20210415220826.29438-12-bvanassche@acm.org
Cc: Hannes Reinecke <hare@kernel.org>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

This was detected by building the kernel with clang and W=1.

Link: https://lore.kernel.org/r/20210415220826.29438-11-bvanassche@acm.org
Cc: Hannes Reinecke <hare@kernel.org>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Fix the following warnings:

drivers/scsi/mpt3sas/mpt3sas_base.c:5430: warning: Excess function parameter 'ct' description in '_base_allocate_pcie_sgl_pool'
drivers/scsi/mpt3sas/mpt3sas_base.c:5493: warning: Excess function parameter 'ctr' description in '_base_allocate_chain_dma_pool'

Link: https://lore.kernel.org/r/20210415220826.29438-10-bvanassche@acm.org
Fixes: d6adc25 ("scsi: mpt3sas: Force PCIe scatterlist allocations to be within same 4 GB region")
Fixes: 7dd847d ("scsi: mpt3sas: Force chain buffer allocations to be within same 4 GB region")
Cc: Sathya Prakash <sathya.prakash@broadcom.com>
Cc: Sreekanth Reddy <sreekanth.reddy@broadcom.com>
Cc: Suganath Prabu Subramani <suganath-prabu.subramani@broadcom.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Suppress the following compiler warning:

warning: cast to smaller integer type
      'enum fip_mode' from 'void *' [-Wvoid-pointer-to-enum-cast]
        enum fip_mode fip_mode = (enum fip_mode)kp->arg;
                                 ^~~~~~~~~~~~~~~~~~~~~~

Link: https://lore.kernel.org/r/20210415220826.29438-9-bvanassche@acm.org
Cc: Hannes Reinecke <hare@suse.de>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Since the 'mfs' member has been declared as 'u32' in include/scsi/libfc.h,
use the %u format specifier instead of %hu. This patch fixes the following
clang compiler warning:

warning: format specifies type
      'unsigned short' but the argument has type 'u32' (aka 'unsigned int')
      [-Wformat]
                             "lport->mfs:%hu\n", mfs, lport->mfs);
                                         ~~~          ^~~~~~~~~~
                                         %u

Link: https://lore.kernel.org/r/20210415220826.29438-8-bvanassche@acm.org
Cc: Hannes Reinecke <hare@suse.de>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

This was detected by building the kernel with clang and W=1.

Link: https://lore.kernel.org/r/20210415220826.29438-7-bvanassche@acm.org
Cc: aacraid@microsemi.com
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Improve readability of the code in the SCSI core by introducing an
enumeration type for the values used internally that decide how to continue
processing a SCSI command. The eh_*_handler return values have not been
changed because that would involve modifying all SCSI drivers.

The output of the following command has been inspected to verify that no
out-of-range values are assigned to a variable of type enum
scsi_disposition:

KCFLAGS=-Wassign-enum make CC=clang W=1 drivers/scsi/

Link: https://lore.kernel.org/r/20210415220826.29438-6-bvanassche@acm.org
Cc: Christoph Hellwig <hch@lst.de>
Cc: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

…BLOCK case

The comment above scsi_send_eh_cmnd() says: "Returns SUCCESS or FAILED or
NEEDS_RETRY". This patch makes all values returned by scsi_send_eh_cmnd()
match the documentation of this function. This change does not affect the
behavior of scsi_eh_tur() nor of scsi_eh_try_stu() nor of the
scsi_request_sense() callers.

See also commit bbe9fb0 ("scsi: Avoid that .queuecommand() gets called
for a blocked SCSI device"; v5.3).

Link: https://lore.kernel.org/r/20210415220826.29438-5-bvanassche@acm.org
Cc: Christoph Hellwig <hch@lst.de>
Cc: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Commit 320ae51 ("blk-mq: new multi-queue block IO queueing mechanism";
v3.13) introduced a code path that calls the blk-mq completion function
from interrupt context. scsi-mq was introduced by commit d285203
("scsi: add support for a blk-mq based I/O path."; v3.17).

Since the introduction of scsi-mq, scsi_softirq_done() can be called from
interrupt context. That made the name of the function misleading, rename it
to scsi_complete().

Link: https://lore.kernel.org/r/20210415220826.29438-4-bvanassche@acm.org
Cc: Christoph Hellwig <hch@lst.de>
Cc: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi_device.sdev_target is used in more code than the single_lun code,
hence remove the comment next to the definition of the sdev_target member.

Link: https://lore.kernel.org/r/20210415220826.29438-3-bvanassche@acm.org
Cc: Christoph Hellwig <hch@lst.de>
Cc: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

The current scsi_alloc_sgtables() documentation does not accurately explain
what this function does. Hence improve the documentation of this function.

Link: https://lore.kernel.org/r/20210415220826.29438-2-bvanassche@acm.org
Cc: Christoph Hellwig <hch@lst.de>
Cc: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Introduce spin lock for outbound queue. With this, driver need not acquire
HBA global lock for outbound queue processing.

Link: https://lore.kernel.org/r/20210415103352.3580-9-Viswas.G@microchip.com
Acked-by: Jack Wang <jinpu.wang@cloud.ionos.com>
Signed-off-by: Viswas G <Viswas.G@microchip.com>
Signed-off-by: Ruksar Devadi <Ruksar.devadi@microchip.com>
Signed-off-by: Ashokkumar N <Ashokkumar.N@microchip.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Producer index(PI) outbound queue and consumer index(CI) for Outbound queue
are in DMA memory. During resume(), the stale PI and CI Values will lead to
unexpected behavior. These values should be reset to 0 during driver
reinitialization.

Link: https://lore.kernel.org/r/20210415103352.3580-8-Viswas.G@microchip.com
Acked-by: Jack Wang <jinpu.wang@cloud.ionos.com>
Signed-off-by: Viswas G <Viswas.G@microchip.com>
Signed-off-by: Ruksar Devadi <Ruksar.devadi@microchip.com>
Signed-off-by: Ashokkumar N <Ashokkumar.N@microchip.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

When controller runs into fatal error, I/Os get stuck with no response,
handler event is defined to complete the pending I/Os (SAS task and
internal task) and also perform the cleanup for the drives.

Link: https://lore.kernel.org/r/20210415103352.3580-7-Viswas.G@microchip.com
Acked-by: Jack Wang <jinpu.wang@cloud.ionos.com>
Signed-off-by: Ruksar Devadi <Ruksar.devadi@microchip.com>
Signed-off-by: Viswas G <Viswas.G@microchip.com>
Signed-off-by: Ashokkumar N <Ashokkumar.N@microchip.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

A new sysfs variable 'ctl_iop1_count' is being introduced that tells if
the controller is alive by indicating controller ticks. If on subsequent
run we see the ticks changing that indicates that controller is not
dead.

Using the 'ctl_iop1_count' sysfs variable we can see ticks incrementing:

    linux-9saw:~# cat  /sys/class/scsi_host/host*/ctl_iop1_count
    0x00000069
    0x0000006b
    0x0000006d
    0x00000072

Link: https://lore.kernel.org/r/20210415103352.3580-6-Viswas.G@microchip.com
Acked-by: Jack Wang <jinpu.wang@ionos.com>
Signed-off-by: Vishakha Channapattan <vishakhavc@google.com>
Signed-off-by: Viswas G <Viswas.G@microchip.com>
Signed-off-by: Ruksar Devadi <Ruksar.devadi@microchip.com>
Signed-off-by: Ashokkumar N <Ashokkumar.N@microchip.com>
Signed-off-by: Radha Ramachandran <radha@google.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

A new sysfs variable 'ctl_iop0_count' is being introduced that tells if
the controller is alive by indicating controller ticks. If on subsequent
run we see the ticks changing that indicates that controller is not
dead.

Using the 'ctl_iop0_count' sysfs variable we can see ticks incrementing:

    linux-9saw:~# cat /sys/class/scsi_host/host*/ctl_iop0_count
    0x000000a3
    0x000001db
    0x000001e4
    0x000001e7

Link: https://lore.kernel.org/r/20210415103352.3580-5-Viswas.G@microchip.com
Acked-by: Jack Wang <jinpu.wang@ionos.com>
Signed-off-by: Vishakha Channapattan <vishakhavc@google.com>
Signed-off-by: Viswas G <Viswas.G@microchip.com>
Signed-off-by: Ruksar Devadi <Ruksar.devadi@microchip.com>
Signed-off-by: Ashokkumar N <Ashokkumar.N@microchip.com>
Signed-off-by: Radha Ramachandran <radha@google.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

A new sysfs variable 'ctl_raae_count' is being introduced that tells if the
controller is alive by indicating controller ticks. If on subsequent run we
see the ticks changing in RAAE count that indicates that controller is not
dead.

Using the 'ctl_raae_count' sysfs variable we can see ticks incrementing:

    linux-9saw:~# cat /sys/class/scsi_host/host*/ctl_raae_count
    0x00002245
    0x00002253
    0x0000225e

Link: https://lore.kernel.org/r/20210415103352.3580-4-Viswas.G@microchip.com
Acked-by: Jack Wang <jinpu.wang@ionos.com>
Signed-off-by: Vishakha Channapattan <vishakhavc@google.com>
Signed-off-by: Viswas G <Viswas.G@microchip.com>
Signed-off-by: Ruksar Devadi <Ruksar.devadi@microchip.com>
Signed-off-by: Ashokkumar N <Ashokkumar.N@microchip.com>
Signed-off-by: Radha Ramachandran <radha@google.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

A new sysfs variable 'ctl_hmi_error' is being introduced to give the error
details if the MPI initialization fails

Using the 'ctl_hmi_error' sysfs variable we can check the error details:

    linux-2dq0:~# cat /sys/class/scsi_host/host*/ctl_hmi_error
    0x00000000
    0x00000000
    0x00000000

Link: https://lore.kernel.org/r/20210415103352.3580-3-Viswas.G@microchip.com
Signed-off-by: Vishakha Channapattan <vishakhavc@google.com>
Signed-off-by: Viswas G <Viswas.G@microchip.com>
Signed-off-by: Ruksar Devadi <Ruksar.devadi@microchip.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

A new sysfs variable 'ctl_mpi_state' is being introduced to check the state
of MPI.

Using the 'ctl_mpi_state' sysfs variable we can check the MPI state:

    linux-2dq0:~# cat /sys/class/scsi_host/host*/ctl_mpi_state
    MPI is successfully initialized

Link: https://lore.kernel.org/r/20210415103352.3580-2-Viswas.G@microchip.com
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Vishakha Channapattan <vishakhavc@google.com>
Signed-off-by: Viswas G <Viswas.G@microchip.com>
Signed-off-by: Ruksar Devadi <Ruksar.devadi@microchip.com>
Signed-off-by: Ashokkumar N <Ashokkumar.N@microchip.com>
Signed-off-by: Radha Ramachandran <radha@google.com>
Signed-off-by: kernel test robot <lkp@intel.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

The qdio layer currently provides its own infrastructure to scan for
Request Queue completions & to report them to the device driver.  This
comes with several drawbacks - having an async tasklet & timer construct in
qdio introduces additional lifetime complexity, and makes it harder to
integrate them with the rest of the device driver. The timeouts are also
currently hard-coded, and can't be tweaked without affecting other qdio
drivers (ie. qeth).

But due to recent enhancements to the qdio layer, zfcp can actually take
full control of the Request Queue completion processing. It merely needs to
opt-out from the qdio layer mechanisms by setting the scan_threshold to 0,
and then use qdio_inspect_queue() to scan for completions.

So re-implement the tasklet & timer mechanism in zfcp, while initially
copying the scan conditions from qdio's handle_outbound() and
qdio_outbound_tasklet(). One minor behavioural change is that
zfcp_qdio_send() will unconditionally reduce the timeout to 1 HZ, rather
than leaving it at 10 Hz if it was last armed by the tasklet. This just
makes things more consistent. Also note that we can drop a lot of the
accumulated cruft in qdio_outbound_tasklet(), as zfcp doesn't even use PCI
interrupt requests any longer.

This also slightly touches the Response Queue processing, as
qdio_get_next_buffers() will no longer implicitly scan for Request Queue
completions. So complete the migration to qdio_inspect_queue() here as well
and make the tasklet_schedule() visible.

Link: https://lore.kernel.org/r/018d3ddd029f8d6ac00cf4184880288c637c4fd1.1618417667.git.bblock@linux.ibm.com
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Place the put_device() call after device_unregister() in both
zfcp_unit_remove() and zfcp_sysfs_port_remove_store() to make it more
natural. put_device() ought to be the last time we touch the object in both
functions.

Add comments after put_device() to make code clearer.

Link: https://lore.kernel.org/r/0a568c7733ba0f1dde28b0c663b90270d44dd540.1618417667.git.bblock@linux.ibm.com
Suggested-by: Steffen Maier <maier@linux.ibm.com>
Suggested-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Qinglang Miao <miaoqinglang@huawei.com>
Signed-off-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

The error path from zfcp_adapter_enqueue() no longer attempts to remove the
diagnostics attributes if they haven't been created yet.

So remove the manual 'sysfs_established' guard for this case, and use
device_add_groups() to add all adapter-related sysfs attributes in one go.

Link: https://lore.kernel.org/r/37a97537f675d643006271f37723c346189b6eec.1618417667.git.bblock@linux.ibm.com
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Reviewed-by: Steffen Maier <maier@linux.ibm.com>
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

When zfcp_adapter_enqueue() fails to create the zfcp_sysfs_adapter_attrs
group, it calls zfcp_adapter_unregister() to tear down the adapter state
again. This then unconditionally attempts to remove the
zfcp_sysfs_adapter_attrs group, resulting in a "group not found" WARN from
sysfs code.

Avoid this by copying most of zfcp_adapter_unregister() into the error
path, allowing for more fine-granular roll-back. Then skip the sysfs
tear-down steps if we haven't progressed this far in the initialization.

Link: https://lore.kernel.org/r/790922cc3af075795fff9a4b787e6bda19bdb3be.1618417667.git.bblock@linux.ibm.com
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Reviewed-by: Steffen Maier <maier@linux.ibm.com>
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Code indentation should use tabs where possible.

Link: https://lore.kernel.org/r/e8a15a2f3d64e2e76a214647cfd4fe23d370b165.1618417667.git.bblock@linux.ibm.com
Signed-off-by: Yevhen Viktorov <yevhen.viktorov@virginmedia.com>
Signed-off-by: Steffen Maier <maier@linux.ibm.com>
Signed-off-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

INIT_LIST_HEAD() is only needed for actual list heads, while req->list is
used as a list entry.

Note that when the error path in zfcp_fsf_req_send() removes the request
from the adapter's list of pending requests, it actually looks up the
request from the zfcp_reqlist - rather than just calling list_del().  So
there's no risk of us calling list_del() on a request that hasn't been
added to any list yet.

Link: https://lore.kernel.org/r/254dc0ae28dccc43ab0b1079ef2c8dcb5fe1d2e4.1618417667.git.bblock@linux.ibm.com
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Reviewed-by: Steffen Maier <maier@linux.ibm.com>
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>