OPP framework can be used to scale the clocks along with other entities
such as regulators, performance state etc... So let's add support for
parsing OPP from devicetree. OPP support in devicetree is added through the
"operating-points-v2" property which accepts the OPP table defining clock
frequency, regulator voltage, power domain performance state etc...

Since the UFS controller requires multiple clocks to be controlled for
proper working, devm_pm_opp_set_config() has been used which supports
scaling multiple clocks through custom ufshcd_opp_config_clks() callback.

It should be noted that the OPP support is not compatible with the old
"freq-table-hz" property. So only one can be used at a time even though
the UFS core supports both.
Co-developed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/20231012172129.65172-4-manivannan.sadhasivam@linaro.orgSigned-off-by: Martin K. Petersen <martin.petersen@oracle.com>

UFS core is only scaling the clocks during devfreq scaling and
initialization. But for an optimum power saving, regulators should also be
scaled along with the clocks.

So let's use the OPP framework which supports scaling clocks, regulators,
and performance state using OPP table defined in devicetree. For
accomodating the OPP support, the existing APIs (ufshcd_scale_clks,
ufshcd_is_devfreq_scaling_required and ufshcd_devfreq_scale) are modified
to accept "freq" as an argument which in turn used by the OPP helpers.

The OPP support is added along with the old freq-table based clock scaling
so that the existing platforms work as expected.
Co-developed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/20231012172129.65172-3-manivannan.sadhasivam@linaro.orgSigned-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Except scaling UFS and bus clocks, it's necessary to scale also the
voltages of regulators or power domain performance state levels.  Adding
Operating Performance Points table allows to adjust power domain
performance state, depending on the UFS clock speed.

OPPv2 deprecates previous property limited to clock scaling:
freq-table-hz.
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/20231012172129.65172-2-manivannan.sadhasivam@linaro.orgSigned-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Wenchao Hao <haowenchao2@huawei.com> says:

The original error injection mechanism was based on scsi_host which
could not inject fault for a single SCSI device.

This patchset provides the ability to inject errors for a single SCSI
device. Now we support inject timeout errors, queuecommand errors, and
hostbyte, driverbyte, statusbyte, and sense data for specific SCSI
Command. Two new error injection is defined to make abort command or
reset LUN failed.

Besides error injection for single device, this patchset add a new
interface to make reset target failed for each scsi_target.

The first two patch add a debugfs interface to add and inquiry single
device's error injection info; the third patch defined how to remove
an injection which has been added. The following 5 patches use the
injection info and generate the related error type. The last two just
add a new interface to make reset target failed and control
scsi_device's allow_restart flag.

Link: https://lore.kernel.org/r/20231010092051.608007-1-haowenchao2@huawei.comSigned-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Add new module param "allow_restart" to control scsi_device's allow_restart
flag. This flag determines if EH is triggered after a command completes
with sense_key 0x6, ASC 0x4 and ASCQ 0x2. EH would be triggered if
allow_restart=1 in this condition.

The new param can be used with the error injection capability to test how
commands completing with sense_key 0x6, ASC 0x4 and ASCQ 0x2 are handled.
Signed-off-by: Wenchao Hao <haowenchao2@huawei.com>
Link: https://lore.kernel.org/r/20231010092051.608007-11-haowenchao2@huawei.comTested-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

The interface is found at
/sys/kernel/debug/scsi_debug/target<h:c:t>/fail_reset where <h:c:t>
identifies the target to inject errors on. It's a simple bool type
interface which would make this target's reset fail if set to 'Y'.
Signed-off-by: Wenchao Hao <haowenchao2@huawei.com>
Link: https://lore.kernel.org/r/20231010092051.608007-10-haowenchao2@huawei.comSigned-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Add error injection type 4 to make scsi_debug_device_reset() return FAILED.
Fail abort command format:

  +--------+------+-------------------------------------------------------+
  | Column | Type | Description                                           |
  +--------+------+-------------------------------------------------------+
  |   1    |  u8  | Error type, fixed to 0x4                              |
  +--------+------+-------------------------------------------------------+
  |   2    |  s32 | Error count                                           |
  |        |      |  0: this rule will be ignored                         |
  |        |      |  positive: the rule will always take effect           |
  |        |      |  negative: the rule takes effect n times where -n is  |
  |        |      |            the value given. Ignored after n times     |
  +--------+------+-------------------------------------------------------+
  |   3    |  x8  | SCSI command opcode, 0xff for all commands            |
  +--------+------+-------------------------------------------------------+

Examples:

    error=/sys/kernel/debug/scsi_debug/0:0:0:1/error
    echo "4 -10 0x12" > ${error}

will make the device return FAILED when trying to reset LUN with inquiry
command 10 times.

    error=/sys/kernel/debug/scsi_debug/0:0:0:1/error
    echo "4 -10 0xff" > ${error}

will make the device return FAILED when trying to reset LUN 10 times.

Usually we do not care about what command it is when trying to perform
reset LUN, so 0xff could be applied.
Signed-off-by: Wenchao Hao <haowenchao2@huawei.com>
Link: https://lore.kernel.org/r/20231010092051.608007-9-haowenchao2@huawei.comTested-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Add error injection type 3 to make scsi_debug_abort() return FAILED.  Fail
abort command format:

  +--------+------+-------------------------------------------------------+
  | Column | Type | Description                                           |
  +--------+------+-------------------------------------------------------+
  |   1    |  u8  | Error type, fixed to 0x3                              |
  +--------+------+-------------------------------------------------------+
  |   2    |  s32 | Error count                                           |
  |        |      |  0: this rule will be ignored                         |
  |        |      |  positive: the rule will always take effect           |
  |        |      |  negative: the rule takes effect n times where -n is  |
  |        |      |            the value given. Ignored after n times     |
  +--------+------+-------------------------------------------------------+
  |   3    |  x8  | SCSI command opcode, 0xff for all commands            |
  +--------+------+-------------------------------------------------------+

Examples:

    error=/sys/kernel/debug/scsi_debug/0:0:0:1/error
    echo "3 -10 0x12" > ${error}

will make the device return FAILED when aborting inquiry command 10 times.
Signed-off-by: Wenchao Hao <haowenchao2@huawei.com>
Link: https://lore.kernel.org/r/20231010092051.608007-8-haowenchao2@huawei.comTested-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

If a fail command error is injected, set the command's status and sense
data then finish this SCSI command.

Set SCSI command's status and sense data format:

  +--------+------+-------------------------------------------------------+
  | Column | Type | Description                                           |
  +--------+------+-------------------------------------------------------+
  |   1    |  u8  | Error type, fixed to 0x2                              |
  +--------+------+-------------------------------------------------------+
  |   2    |  s32 | Error Count                                           |
  |        |      |  0: the rule will be ignored                          |
  |        |      |  positive: the rule will always take effect           |
  |        |      |  negative: the rule takes effect n times where -n is  |
  |        |      |            the value given. Ignored after n times     |
  +--------+------+-------------------------------------------------------+
  |   3    |  x8  | SCSI command opcode, 0xff for all commands            |
  +--------+------+-------------------------------------------------------+
  |   4    |  x8  | Host byte in scsi_cmd::status                         |
  |        |      | [scsi_cmd::status has 32 bits holding these 3 bytes]  |
  +--------+------+-------------------------------------------------------+
  |   5    |  x8  | Driver byte in scsi_cmd::status                       |
  +--------+------+-------------------------------------------------------+
  |   6    |  x8  | SCSI Status byte in scsi_cmd::status                  |
  +--------+------+-------------------------------------------------------+
  |   7    |  x8  | SCSI Sense Key in scsi_cmnd                           |
  +--------+------+-------------------------------------------------------+
  |   8    |  x8  | SCSI ASC in scsi_cmnd                                 |
  +--------+------+-------------------------------------------------------+
  |   9    |  x8  | SCSI ASCQ in scsi_cmnd                                |
  +--------+------+-------------------------------------------------------+

Examples:
    error=/sys/kernel/debug/scsi_debug/0:0:0:1/error
    echo "2 -10 0x88 0 0 0x2 0x3 0x11 0x0" >${error}

will make device's read command return with media error with additional
sense of "Unrecovered read error" (UNC):
Acked-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: Wenchao Hao <haowenchao2@huawei.com>
Link: https://lore.kernel.org/r/20231010092051.608007-7-haowenchao2@huawei.comSigned-off-by: Martin K. Petersen <martin.petersen@oracle.com>

If a fail queuecommand error is injected, return the failed value defined
in the rule from queuecommand.

Make queuecommand return format:

  +--------+------+-------------------------------------------------------+
  | Column | Type | Description                                           |
  +--------+------+-------------------------------------------------------+
  |   1    |  u8  | Error type, fixed to 0x1                              |
  +--------+------+-------------------------------------------------------+
  |   2    |  s32 | Error count                                           |
  |        |      |  0: this rule will be ignored                         |
  |        |      |  positive: the rule will always take effect           |
  |        |      |  negative: the rule takes effect n times where -n is  |
  |        |      |            the value given. Ignored after n times     |
  +--------+------+-------------------------------------------------------+
  |   3    |  x8  | SCSI command opcode, 0xff for all commands            |
  +--------+------+-------------------------------------------------------+
  |   4    |  x32 | The queuecommand() return value we want               |
  +--------+------+-------------------------------------------------------+

Examples:

    error=/sys/kernel/debug/scsi_debug/0:0:0:1/error
    echo "1 1 0x12 0x1055" > ${error}

will make each INQUIRY command sent to that device return 0x1055
(SCSI_MLQUEUE_HOST_BUSY).
Acked-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: Wenchao Hao <haowenchao2@huawei.com>
Link: https://lore.kernel.org/r/20231010092051.608007-6-haowenchao2@huawei.comSigned-off-by: Martin K. Petersen <martin.petersen@oracle.com>

If a timeout error is injected, return 0 from scsi_debug_queuecommand to
make the command time out.

Time out SCSI command format:

  +--------+------+-------------------------------------------------------+
  | Column | Type | Description                                           |
  +--------+------+-------------------------------------------------------+
  |   1    |  u8  | Error type, fixed to 0x0                              |
  +--------+------+-------------------------------------------------------+
  |   2    |  s32 | Error count                                           |
  |        |      |  0: this rule will be ignored                         |
  |        |      |  positive: the rule will always take effect           |
  |        |      |  negative: the rule takes effect n times where -n is  |
  |        |      |            the value given. Ignored after n times     |
  +--------+------+-------------------------------------------------------+
  |   3    |  x8  | SCSI command opcode, 0xff for all commands            |
  +--------+------+-------------------------------------------------------+

Examples:

    error=/sys/kernel/debug/scsi_debug/0:0:0:1/error
    echo "0 -10 0x12" > ${error}

will make the device's inquiry command time out 10 times.

    echo "0 1 0x12" > ${error}

will make the device's inquiry time out each time it is invoked on this
device.
Acked-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: Wenchao Hao <haowenchao2@huawei.com>
Link: https://lore.kernel.org/r/20231010092051.608007-5-haowenchao2@huawei.comSigned-off-by: Martin K. Petersen <martin.petersen@oracle.com>

The grammar to remove error injection is a line with fixed 3 columns
separated by spaces.

First column is fixed to "-". It tells this is a removal operation.  Second
column is the error code to match.  Third column is the scsi command to
match.

For example the following command would remove timeout injection of inquiry
command:

    echo "- 0 0x12" > /sys/kernel/debug/scsi_debug/0:0:0:1/error
Acked-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: Wenchao Hao <haowenchao2@huawei.com>
Link: https://lore.kernel.org/r/20231010092051.608007-4-haowenchao2@huawei.comSigned-off-by: Martin K. Petersen <martin.petersen@oracle.com>

This new facility uses the debugfs pseudo file system which is typically
mounted under the /sys/kernel/debug directory and requires root permissions
to access.

The interface file is found at /sys/kernel/debug/scsi_debug/<h:c:t:l>/error
where <h:c:t:l> identifies the device (logical unit (LU)) to inject errors
on.

For the following description the ${error} environment variable is assumed
to be set to/sys/kernel/debug/scsi_debug/1:0:0:0/error where 1:0:0:0 is a
pseudo device (LU) owned by the scsi_debug driver. Rules are written to
${error} in the normal sysfs fashion (e.g. 'echo "0 -2 0x12" > ${error}').

More than one rule can be active on a device at a time and inactive rules
(i.e. those whose error count is 0) remain in the rule listing. The
existing rules can be read with 'cat ${error}' with oneline output for each
rule.

The interface format is line-by-line, each line is an error injection rule.
Each rule contains integers separated by spaces, the first three columns
correspond to "Error code", "Error count" and "SCSI command", other
columns depend on Error code.

General rule format:
  +--------+------+-------------------------------------------------------+
  | Column | Type | Description                                           |
  +--------+------+-------------------------------------------------------+
  |   1    |  u8  | Error code                                            |
  |        |      |  0: timeout SCSI command                              |
  |        |      |  1: fail queuecommand, make queuecommand return       |
  |        |      |     given value                                       |
  |        |      |  2: fail command, finish command with SCSI status,    |
  |        |      |     sense key and ASC/ASCQ values                     |
  |        |      |  3: make abort commands for specific command fail     |
  |        |      |  4: make reset lun for specific command fail          |
  +--------+------+-------------------------------------------------------+
  |   2    |  s32 | Error count                                           |
  |        |      |  0: this rule will be ignored                         |
  |        |      |  positive: the rule will always take effect           |
  |        |      |  negative: the rule takes effect n times where -n is  |
  |        |      |            the value given. Ignored after n times     |
  +--------+------+-------------------------------------------------------+
  |   3    |  x8  | SCSI command opcode, 0xff for all commands            |
  +--------+------+-------------------------------------------------------+
  |  ...   |  xxx | Error type specific fields                            |
  +--------+------+-------------------------------------------------------+

Notes:

 - When multiple error inject rules are added for the same SCSI command,
   the one with smaller error code will take effect (and the others will be
   ignored).

 - If the same error (i.e. same Error code and SCSI command) is added, the
   older one will be overwritten..

 - Currently, the basic types are (u8/u16/u32/u64/s8/s16/s32/s64) and the
   hexadecimal types (x8/x16/x32/x64).

 - Where a hexadecimal value is expected (e.g. Column 3: SCSI command
   opcode) the "0x" prefix is optional on the value (e.g. the INQUIRY
   opcode can be given as '0x12' or '12').

 - When the Error count is negative, reading ${error} will show that value
   incrementing, stopping when it gets to 0.
Acked-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: Wenchao Hao <haowenchao2@huawei.com>
Link: https://lore.kernel.org/r/20231010092051.608007-3-haowenchao2@huawei.comSigned-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Create directory scsi_debug in the root of the debugfs filesystem.  Prepare
to add interface for manage error injection.
Acked-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: Wenchao Hao <haowenchao2@huawei.com>
Link: https://lore.kernel.org/r/20231010092051.608007-2-haowenchao2@huawei.comSigned-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Justin Tee <justintee8345@gmail.com> says:

Update lpfc to revision 14.2.0.15

This patch set contains error handling fixes, ELS bug fixes, and
logging improvements.

The patches were cut against Martin's 6.7/scsi-queue tree.

Link: https://lore.kernel.org/r/20231009161812.97232-1-justintee8345@gmail.comSigned-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Update lpfc version to 14.2.0.15.
Signed-off-by: Justin Tee <justin.tee@broadcom.com>
Link: https://lore.kernel.org/r/20231009161812.97232-7-justintee8345@gmail.comSigned-off-by: Martin K. Petersen <martin.petersen@oracle.com>

The preexisting LOG_NODE message flag frequently spams a subset of the same
log messages during normal FC driver operations.  When analyzing driver
logs, this sometimes leads to difficulty in troubleshooting.

Because LOG_IP log message flag is unused, convert it to a new
LOG_NODE_VERBOSE flag.  The LOG_NODE_VERBOSE shall specifically be used for
diagnosing issues that require precise ndlp tracking detail.
Signed-off-by: Justin Tee <justin.tee@broadcom.com>
Link: https://lore.kernel.org/r/20231009161812.97232-6-justintee8345@gmail.comSigned-off-by: Martin K. Petersen <martin.petersen@oracle.com>

A WCQE success completion status does not guarantee valid LS_ACC receipt
for ELS commands.  So, introduce a small helper routine that validates ELS
LS_ACC frames in ELS cmpl routines.
Signed-off-by: Justin Tee <justin.tee@broadcom.com>
Link: https://lore.kernel.org/r/20231009161812.97232-5-justintee8345@gmail.comSigned-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Currently, NPIV ports send PRLI_ACC to all received unsolicited PRLI
requests.  For an NPIV port, there is no point to PRLI_ACC if the received
PRLI request has the initiator function bit set and the target function bit
unset.  Modify the lpfc_rcv_prli_support_check() routine to send a PRLI_RJT
in such cases.  NPIV ports are expected to send PRLI_ACC only if the Target
function bit is set.
Signed-off-by: Justin Tee <justin.tee@broadcom.com>
Link: https://lore.kernel.org/r/20231009161812.97232-4-justintee8345@gmail.comSigned-off-by: Martin K. Petersen <martin.petersen@oracle.com>

During receipt of a hardware error attention ACQE, IOERR_SLI_DOWN status is
set by the driver for all outstanding I/Os.

In such hardware error attention cases, we can treat the situation exactly
the same as pci_channel_offline.  Thus, add IOERR_SLI_DOWN status to the
same category as pci_channel_offline handling in lpfc_nvme_io_cmd_cmpl.
Signed-off-by: Justin Tee <justin.tee@broadcom.com>
Link: https://lore.kernel.org/r/20231009161812.97232-3-justintee8345@gmail.comSigned-off-by: Martin K. Petersen <martin.petersen@oracle.com>

In order to enter the !rc if statement block in question, rc had to have
been zero to begin with.  Thus, the rc = 0 assignment is unnecessary and
can be removed.
Signed-off-by: Justin Tee <justin.tee@broadcom.com>
Link: https://lore.kernel.org/r/20231009161812.97232-2-justintee8345@gmail.comSigned-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Chandrakanth patil <chandrakanth.patil@broadcom.com> says:

This set of patches includes critical fixes, and updates to the
maintainer list.

Link: https://lore.kernel.org/r/20231003110021.168862-1-chandrakanth.patil@broadcom.comSigned-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Given my active involvement in megaraid_sas development, I am including
myself in the maintainers list.
Signed-off-by: Chandrakanth patil <chandrakanth.patil@broadcom.com>
Link: https://lore.kernel.org/r/20231003110021.168862-5-chandrakanth.patil@broadcom.comSigned-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Driver version update.
Signed-off-by: Chandrakanth patil <chandrakanth.patil@broadcom.com>
Link: https://lore.kernel.org/r/20231003110021.168862-4-chandrakanth.patil@broadcom.comSigned-off-by: Martin K. Petersen <martin.petersen@oracle.com>

The driver now includes the print message 'IO is completed, no reset is
required' when a reset is requested but not issued. This message is
displayed only when pending SCSI IO is completed before issuing the reset.
Signed-off-by: Chandrakanth patil <chandrakanth.patil@broadcom.com>
Signed-off-by: Sumit Saxena <sumit.saxena@broadcom.com>
Link: https://lore.kernel.org/r/20231003110021.168862-3-chandrakanth.patil@broadcom.comSigned-off-by: Martin K. Petersen <martin.petersen@oracle.com>

In BMC environments with concurrent access to multiple registers, certain
registers occasionally yield a value of 0 even after 3 retries due to
hardware errata. As a fix, we have extended the retry count from 3 to 30.

The same errata applies to the mpt3sas driver, and a similar patch has
been accepted. Please find more details in the mpt3sas patch reference
link.

Link: https://lore.kernel.org/r/20230829090020.5417-2-ranjan.kumar@broadcom.com
Fixes: 272652fc ("scsi: megaraid_sas: add retry logic in megasas_readl")
Cc: stable@vger.kernel.org
Signed-off-by: Chandrakanth patil <chandrakanth.patil@broadcom.com>
Signed-off-by: Sumit Saxena <sumit.saxena@broadcom.com>
Link: https://lore.kernel.org/r/20231003110021.168862-2-chandrakanth.patil@broadcom.comSigned-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Mike Christie <michael.christie@oracle.com> says:

The following patches were made over Linus tree (Martin's 6.7 branch
was missing some changes to sd.c). They only contain the sshdr and
rdac retry fixes from the "Allow scsi_execute users to control
retries" patchset.

The patches in this set are reviewed and tested but the changes to how
we do retries will take a little longer and require more testing, so I
broke up the series to make them easier to review.

Link: https://lore.kernel.org/r/20231004210013.5601-1-michael.christie@oracle.comSigned-off-by: Martin K. Petersen <martin.petersen@oracle.com>

If scsi_execute_cmd returns < 0, it doesn't initialize the sshdr, so we
shouldn't access the sshdr. If it returns 0, then the cmd executed
successfully, so there is no need to check the sshdr. This has us access
the sshdr when we get a return value > 0.
Signed-off-by: Mike Christie <michael.christie@oracle.com>
Link: https://lore.kernel.org/r/20231004210013.5601-13-michael.christie@oracle.comReviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: John Garry <john.g.garry@oracle.com>
Reviewed-by: Martin Wilck <mwilck@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

If scsi_execute_cmd returns < 0, it doesn't initialize the sshdr, so we
shouldn't access the sshdr. If it returns 0, then the cmd executed
successfully, so there is no need to check the sshdr. This has us access
the sshdr when we get a return value > 0.
Signed-off-by: Mike Christie <michael.christie@oracle.com>
Link: https://lore.kernel.org/r/20231004210013.5601-12-michael.christie@oracle.comReviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: John Garry <john.g.garry@oracle.com>
Reviewed-by: Martin Wilck <mwilck@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

If scsi_execute_cmd returns < 0, it doesn't initialize the sshdr, so we
shouldn't access the sshdr. If it returns 0, then the cmd executed
successfully, so there is no need to check the sshdr. This has us access
the sshdr when we get a return value > 0.
Signed-off-by: Mike Christie <michael.christie@oracle.com>
Link: https://lore.kernel.org/r/20231004210013.5601-11-michael.christie@oracle.comReviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: John Garry <john.g.garry@oracle.com>
Reviewed-by: Martin Wilck <mwilck@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

If scsi_execute_cmd returns < 0, it doesn't initialize the sshdr, so we
shouldn't access the sshdr. If it returns 0, then the cmd executed
successfully, so there is no need to check the sshdr. This has us access
the sshdr when we get a return value > 0.
Signed-off-by: Mike Christie <michael.christie@oracle.com>
Link: https://lore.kernel.org/r/20231004210013.5601-10-michael.christie@oracle.comReviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: John Garry <john.g.garry@oracle.com>
Reviewed-by: Martin Wilck <mwilck@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

The sshdr passed into scsi_execute_cmd is only initialized if
scsi_execute_cmd returns >= 0, and scsi_mode_sense will convert all non
good statuses like check conditions to -EIO. This has scsi_mode_sense
callers that were possibly accessing an uninitialized sshdrs to only
access it if we got -EIO.
Signed-off-by: Mike Christie <michael.christie@oracle.com>
Link: https://lore.kernel.org/r/20231004210013.5601-9-michael.christie@oracle.comReviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin Wilck <mwilck@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

If scsi_execute_cmd returns < 0, it doesn't initialize the sshdr, so we
shouldn't access the sshdr. If it returns 0, then the cmd executed
successfully, so there is no need to check the sshdr. This has us access
the sshdr when we get a return value > 0.
Signed-off-by: Mike Christie <michael.christie@oracle.com>
Link: https://lore.kernel.org/r/20231004210013.5601-7-michael.christie@oracle.comReviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: John Garry <john.g.garry@oracle.com>
Reviewed-by: Martin Wilck <mwilck@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

If scsi_execute_cmd returns < 0, it doesn't initialize the sshdr, so we
shouldn't access the sshdr. If it returns 0, then the cmd executed
successfully, so there is no need to check the sshdr. This has us access
the sshdr when we get a return value > 0.
Signed-off-by: Mike Christie <michael.christie@oracle.com>
Link: https://lore.kernel.org/r/20231004210013.5601-6-michael.christie@oracle.comReviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin Wilck <mwilck@suse.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

If send_mode_select retries scsi_execute_cmd it will leave err set to
SCSI_DH_RETRY/SCSI_DH_IMM_RETRY. If on the retry, the command is
successful, then SCSI_DH_RETRY/SCSI_DH_IMM_RETRY will be returned to the
scsi_dh activation caller. On the retry, we will then detect the previous
MODE SELECT had worked, and so we will return success.

This patch has us return the correct return value, so we can avoid the
extra scsi_dh activation call and to avoid failures if the caller had hit
its activation retry limit and does not end up retrying.
Signed-off-by: Mike Christie <michael.christie@oracle.com>
Link: https://lore.kernel.org/r/20231004210013.5601-5-michael.christie@oracle.comReviewed-by: Martin Wilck <mwilck@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

If scsi_execute_cmd returns < 0, it doesn't initialize the sshdr, so we
shouldn't access the sshdr. If it returns 0, then the cmd executed
successfully, so there is no need to check the sshdr. This has us access
the sshdr when we get a return value > 0.
Signed-off-by: Mike Christie <michael.christie@oracle.com>
Link: https://lore.kernel.org/r/20231004210013.5601-4-michael.christie@oracle.comReviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: John Garry <john.g.garry@oracle.com>
Reviewed-by: Martin Wilck <mwilck@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

If scsi_execute_cmd returns < 0, it doesn't initialize the sshdr, so we
shouldn't access the sshdr. If it returns 0, then the cmd executed
successfully, so there is no need to check the sshdr. This has us access
the sshdr when we get a return value > 0.
Signed-off-by: Mike Christie <michael.christie@oracle.com>
Link: https://lore.kernel.org/r/20231004210013.5601-3-michael.christie@oracle.comReviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: John Garry <john.g.garry@oracle.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Martin Wilck <mwilck@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

If scsi_execute_cmd returns < 0, it doesn't initialize the sshdr, so we
shouldn't access the sshdr. If it returns 0, then the cmd executed
successfully, so there is no need to check the sshdr. This has us access
the sshdr when we get a return value > 0.
Signed-off-by: Mike Christie <michael.christie@oracle.com>
Link: https://lore.kernel.org/r/20231004210013.5601-2-michael.christie@oracle.comReviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: John Garry <john.g.garry@oracle.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Martin Wilck <mwilck@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Mike Christie <michael.christie@oracle.com> says:

The following patches were made over Linus's tree but apply over
Martin's branches. They allow userspace to configure how fabric
drivers submit cmds to backend drivers.

Right now loop and vhost use a worker thread, and the other drivers
submit from the contexts they receive/process the cmd from. For
multiple LUN cases where the target can queue more cmds than the
backend can handle then deferring to a worker thread is safest because
the backend driver can block when doing things like waiting for a free
request/tag. Deferring also helps when the target has to handle
transport level requests from the recv context.

For cases where the backend devices can queue everything the target
sends, then there is no need to defer to a workqueue and you can see a
perf boost of up to 26% for small IO workloads. For a nvme device and
vhost-scsi I can see with 4K IOs:

fio jobs        1       2       4       8       10
--------------------------------------------------
workqueue
submit        94K     190K    394K    770K    890K

direct
submit       128K     252K    488K    950K    -

Link: https://lore.kernel.org/r/1b1f7a5c-0988-45f9-b103-dfed2c0405b1@oracle.comSigned-off-by: Martin K. Petersen <martin.petersen@oracle.com>

This exports the fabric driver's direct submit settings, so users know what
the driver supports. It will be helpful when they are exporting a device
through different targets and one doesn't support direct submission.

The new files allow the fabric to report what submission types they default
to and if they support direct submission:

default_submit_type:

 1 - TARGET_DIRECT_SUBMIT - If the user has not requested a specific value
     then the fabric requests direct submission.

 2 - TARGET_QUEUE_SUBMIT - If the user has not requested a specific value
     then the fabric requests queued submission.

Note that these fabric values are based on what the fabric driver currently
defaults to for compat with exiting setups.

direct_submit_supported:

 0 - The fabric does not support direct submission.

 1 - The fabric supports direct submission.
Signed-off-by: Mike Christie <michael.christie@oracle.com>
Link: https://lore.kernel.org/r/20230928020907.5730-8-michael.christie@oracle.comSigned-off-by: Martin K. Petersen <martin.petersen@oracle.com>