ata: libata-scsi: Fix ata_scsi_dev_rescan() error path

Commit 0c76106cb975 ("scsi: sd: Fix TCG OPAL unlock on system resume")
incorrectly handles failures of scsi_resume_device() in
ata_scsi_dev_rescan(), leading to a double call to
spin_unlock_irqrestore() to unlock a device port. Fix this by redefining
the goto labels used in case of errors and only unlock the port
scsi_scan_mutex when scsi_resume_device() fails.

Bug found with the Smatch static checker warning:

drivers/ata/libata-scsi.c:4774 ata_scsi_dev_rescan()
error: double unlocked 'ap->lock' (orig line 4757)

Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Fixes: 0c76106cb975 ("scsi: sd: Fix TCG OPAL unlock on system resume")
Cc: stable@vger.kernel.org
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Niklas Cassel <cassel@kernel.org>

scsi: sd: Fix TCG OPAL unlock on system resume

Commit 3cc2ffe5c16d ("scsi: sd: Differentiate system and runtime start/stop
management") introduced the manage_system_start_stop scsi_device flag to
allow libata to indicate to the SCSI disk driver that nothing should be
done when resuming a disk on system resume. This change turned the
execution of sd_resume() into a no-op for ATA devices on system
resume. While this solved deadlock issues during device resume, this change
also wrongly removed the execution of opal_unlock_from_suspend(). As a
result, devices with TCG OPAL locking enabled remain locked and
inaccessible after a system resume from sleep.

To fix this issue, introduce the SCSI driver resume method and implement it
with the sd_resume() function calling opal_unlock_from_suspend(). The
former sd_resume() function is renamed to sd_resume_common() and modified
to call the new sd_resume() function. For non-ATA devices, this result in
no functional changes.

In order for libata to explicitly execute sd_resume() when a device is
resumed during system restart, the function scsi_resume_device() is
introduced. libata calls this function from the revalidation work executed
on devie resume, a state that is indicated with the new device flag
ATA_DFLAG_RESUMING. Doing so, locked TCG OPAL enabled devices are unlocked
on resume, allowing normal operation.

Fixes: 3cc2ffe5c16d ("scsi: sd: Differentiate system and runtime start/stop management")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=218538
Cc: stable@vger.kernel.org
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Link: https://lore.kernel.org/r/20240319071209.1179257-1-dlemoal@kernel.org
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: sd: Fix system start for ATA devices

It is not always possible to keep a device in the runtime suspended state
when a system level suspend/resume cycle is executed. E.g. for ATA devices
connected to AHCI adapters, system resume resets the ATA ports, which
causes connected devices to spin up. In such case, a runtime suspended disk
will incorrectly be seen with a suspended runtime state because the device
is not resumed by sd_resume_system(). The power state seen by the user is
different than the actual device physical power state.

Fix this issue by introducing the struct scsi_device flag
force_runtime_start_on_system_start. When set, this flag causes
sd_resume_system() to request a runtime resume operation for runtime
suspended devices. This results in the user seeing the device runtime_state
as active after a system resume, thus correctly reflecting the device
physical power state.

Fixes: 9131bff6a9f1 ("scsi: core: pm: Only runtime resume if necessary")
Cc: <stable@vger.kernel.org>
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Link: https://lore.kernel.org/r/20231120225631.37938-3-dlemoal@kernel.org
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: Change SCSI device boolean fields to single bit flags

Commit 3cc2ffe5c16d ("scsi: sd: Differentiate system and runtime start/stop
management") changed the single bit manage_start_stop flag into 2 boolean
fields of the SCSI device structure. Commit 24eca2dce0f8 ("scsi: sd:
Introduce manage_shutdown device flag") introduced the manage_shutdown
boolean field for the same structure. Together, these 2 commits increase
the size of struct scsi_device by 8 bytes by using booleans instead of
defining the manage_xxx fields as single bit flags, similarly to other
flags of this structure.

Avoid this unnecessary structure size increase and be consistent with the
definition of other flags by reverting the definitions of the manage_xxx
fields as single bit flags.

Fixes: 3cc2ffe5c16d ("scsi: sd: Differentiate system and runtime start/stop management")
Fixes: 24eca2dce0f8 ("scsi: sd: Introduce manage_shutdown device flag")
Cc: <stable@vger.kernel.org>
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Link: https://lore.kernel.org/r/20231120225631.37938-2-dlemoal@kernel.org
Reviewed-by: Niklas Cassel <niklas.cassel@wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

ata: libata-scsi: Cleanup ata_scsi_start_stop_xlat()

Now that libata does its own internal device power mode management
through libata EH, the scsi disk driver will not issue START STOP UNIT
commands anymore. We can receive this command only from user passthrough
operations. So there is no need to consider the system state and ATA
port flags for suspend to translate the command.

Since setting up the taskfile for the verify and standby
immediate commands is the same as done in ata_dev_power_set_active()
and ata_dev_power_set_standby(), factor out this code into the helper
function ata_dev_power_init_tf() to simplify ata_scsi_start_stop_xlat()
as well as ata_dev_power_set_active() and ata_dev_power_set_standby().

Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Tested-by: Chia-Lin Kao (AceLan) <acelan.kao@canonical.com>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: sd: Introduce manage_shutdown device flag

Commit aa3998dbeb3a ("ata: libata-scsi: Disable scsi device
manage_system_start_stop") change setting the manage_system_start_stop
flag to false for libata managed disks to enable libata internal
management of disk suspend/resume. However, a side effect of this change
is that on system shutdown, disks are no longer being stopped (set to
standby mode with the heads unloaded). While this is not a critical
issue, this unclean shutdown is not recommended and shows up with
increased smart counters (e.g. the unexpected power loss counter
"Unexpect_Power_Loss_Ct").

Instead of defining a shutdown driver method for all ATA adapter
drivers (not all of them define that operation), this patch resolves
this issue by further refining the sd driver start/stop control of disks
using the new flag manage_shutdown. If this new flag is set to true by
a low level driver, the function sd_shutdown() will issue a
START STOP UNIT command with the start argument set to 0 when a disk
needs to be powered off (suspended) on system power off, that is, when
system_state is equal to SYSTEM_POWER_OFF.

Similarly to the other manage_xxx flags, the new manage_shutdown flag is
exposed through sysfs as a read-write device attribute.

To avoid any confusion between manage_shutdown and
manage_system_start_stop, the comments describing these flags in
include/scsi/scsi.h are also improved.

Fixes: aa3998dbeb3a ("ata: libata-scsi: Disable scsi device manage_system_start_stop")
Cc: stable@vger.kernel.org
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218038
Link: https://lore.kernel.org/all/cd397c88-bf53-4768-9ab8-9d107df9e613@gmail.com/
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Niklas Cassel <niklas.cassel@wdc.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Acked-by: Martin K. Petersen <martin.petersen@oracle.com>

ata: libata-scsi: Fix delayed scsi_rescan_device() execution

Commit 6aa0365a3c85 ("ata: libata-scsi: Avoid deadlock on rescan after
device resume") modified ata_scsi_dev_rescan() to check the scsi device
"is_suspended" power field to ensure that the scsi device associated
with an ATA device is fully resumed when scsi_rescan_device() is
executed. However, this fix is problematic as:
1) It relies on a PM internal field that should not be used without PM
device locking protection.
2) The check for is_suspended and the call to scsi_rescan_device() are
not atomic and a suspend PM event may be triggered between them,
casuing scsi_rescan_device() to be called on a suspended device and
in that function blocking while holding the scsi device lock. This
would deadlock a following resume operation.
These problems can trigger PM deadlocks on resume, especially with
resume operations triggered quickly after or during suspend operations.
E.g., a simple bash script like:

for (( i=0; i<10; i++ )); do
echo "+2 > /sys/class/rtc/rtc0/wakealarm
echo mem > /sys/power/state
done

that triggers a resume 2 seconds after starting suspending a system can
quickly lead to a PM deadlock preventing the system from correctly
resuming.

Fix this by replacing the check on is_suspended with a check on the
return value given by scsi_rescan_device() as that function will fail if
called against a suspended device. Also make sure rescan tasks already
scheduled are first cancelled before suspending an ata port.

Fixes: 6aa0365a3c85 ("ata: libata-scsi: Avoid deadlock on rescan after device resume")
Cc: stable@vger.kernel.org
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Niklas Cassel <niklas.cassel@wdc.com>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>

ata: libata-scsi: Disable scsi device manage_system_start_stop

The introduction of a device link to create a consumer/supplier
relationship between the scsi device of an ATA device and the ATA port
of that ATA device fixes the ordering of system suspend and resume
operations. For suspend, the scsi device is suspended first and the ata
port after it. This is fine as this allows the synchronize cache and
START STOP UNIT commands issued by the scsi disk driver to be executed
before the ata port is disabled.

For resume operations, the ata port is resumed first, followed
by the scsi device. This allows having the request queue of the scsi
device to be unfrozen after the ata port resume is scheduled in EH,
thus avoiding to see new requests prematurely issued to the ATA device.
Since libata sets manage_system_start_stop to 1, the scsi disk resume
operation also results in issuing a START STOP UNIT command to the
device being resumed so that the device exits standby power mode.

However, restoring the ATA device to the active power mode must be
synchronized with libata EH processing of the port resume operation to
avoid either 1) seeing the start stop unit command being received too
early when the port is not yet resumed and ready to accept commands, or
after the port resume process issues commands such as IDENTIFY to
revalidate the device. In this last case, the risk is that the device
revalidation fails with timeout errors as the drive is still spun down.

Commit 0a8589055936 ("ata,scsi: do not issue START STOP UNIT on resume")
disabled issuing the START STOP UNIT command to avoid issues with it.
But this is incorrect as transitioning a device to the active power
mode from the standby power mode set on suspend requires a media access
command. The IDENTIFY, READ LOG and SET FEATURES commands executed in
libata EH context triggered by the ata port resume operation may thus
fail.

Fix these synchronization issues is by handling a device power mode
transitions for system suspend and resume directly in libata EH context,
without relying on the scsi disk driver management triggered with the
manage_system_start_stop flag.

To do this, the following libata helper functions are introduced:

1) ata_dev_power_set_standby():

This function issues a STANDBY IMMEDIATE command to transitiom a device
to the standby power mode. For HDDs, this spins down the disks. This
function applies only to ATA and ZAC devices and does nothing otherwise.
This function also does nothing for devices that have the
ATA_FLAG_NO_POWEROFF_SPINDOWN or ATA_FLAG_NO_HIBERNATE_SPINDOWN flag
set.

For suspend, call ata_dev_power_set_standby() in
ata_eh_handle_port_suspend() before the port is disabled and frozen.
ata_eh_unload() is also modified to transition all enabled devices to
the standby power mode when the system is shutdown or devices removed.

2) ata_dev_power_set_active() and

This function applies to ATA or ZAC devices and issues a VERIFY command
for 1 sector at LBA 0 to transition the device to the active power mode.
For HDDs, since this function will complete only once the disk spin up.
Its execution uses the same timeouts as for reset, to give the drive
enough time to complete spinup without triggering a command timeout.

For resume, call ata_dev_power_set_active() in
ata_eh_revalidate_and_attach() after the port has been enabled and
before any other command is issued to the device.

With these changes, the manage_system_start_stop and no_start_on_resume
scsi device flags do not need to be set in ata_scsi_dev_config(). The
flag manage_runtime_start_stop is still set to allow the sd driver to
spinup/spindown a disk through the sd runtime operations.

Fixes: 0a8589055936 ("ata,scsi: do not issue START STOP UNIT on resume")
Cc: stable@vger.kernel.org
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: sd: Differentiate system and runtime start/stop management

The underlying device and driver of a SCSI disk may have different
system and runtime power mode control requirements. This is because
runtime power management affects only the SCSI disk, while system level
power management affects all devices, including the controller for the
SCSI disk.

For instance, issuing a START STOP UNIT command when a SCSI disk is
runtime suspended and resumed is fine: the command is translated to a
STANDBY IMMEDIATE command to spin down the ATA disk and to a VERIFY
command to wake it up. The SCSI disk runtime operations have no effect
on the ata port device used to connect the ATA disk. However, for
system suspend/resume operations, the ATA port used to connect the
device will also be suspended and resumed, with the resume operation
requiring re-validating the device link and the device itself. In this
case, issuing a VERIFY command to spinup the disk must be done before
starting to revalidate the device, when the ata port is being resumed.
In such case, we must not allow the SCSI disk driver to issue START STOP
UNIT commands.

Allow a low level driver to refine the SCSI disk start/stop management
by differentiating system and runtime cases with two new SCSI device
flags: manage_system_start_stop and manage_runtime_start_stop. These new
flags replace the current manage_start_stop flag. Drivers setting the
manage_start_stop are modifed to set both new flags, thus preserving the
existing start/stop management behavior. For backward compatibility, the
old manage_start_stop sysfs device attribute is kept as a read-only
attribute showing a value of 1 for devices enabling both new flags and 0
otherwise.

Fixes: 0a8589055936 ("ata,scsi: do not issue START STOP UNIT on resume")
Cc: stable@vger.kernel.org
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>

ata: libata-scsi: link ata port and scsi device

There is no direct device ancestry defined between an ata_device and
its scsi device which prevents the power management code from correctly
ordering suspend and resume operations. Create such ancestry with the
ata device as the parent to ensure that the scsi device (child) is
suspended before the ata device and that resume handles the ata device
before the scsi device.

The parent-child (supplier-consumer) relationship is established between
the ata_port (parent) and the scsi device (child) with the function
device_add_link(). The parent used is not the ata_device as the PM
operations are defined per port and the status of all devices connected
through that port is controlled from the port operations.

The device link is established with the new function
ata_scsi_slave_alloc(), and this function is used to define the
->slave_alloc callback of the scsi host template of all ata drivers.

Fixes: a19a93e4c6a9 ("scsi: core: pm: Rely on the device driver core for async power management")
Cc: stable@vger.kernel.org
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Niklas Cassel <niklas.cassel@wdc.com>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: John Garry <john.g.garry@oracle.com>

ata: libata-scsi: ignore reserved bits for REPORT SUPPORTED OPERATION CODES

For REPORT SUPPORTED OPERATION CODES command, the service action field is
defined as bits 0-4 in the second byte in the CDB. Bits 5-7 in the second
byte are reserved.

Only look at the service action field in the second byte when determining
if the MAINTENANCE IN opcode is a REPORT SUPPORTED OPERATION CODES command.

This matches how we only look at the service action field in the second
byte when determining if the SERVICE ACTION IN(16) opcode is a READ
CAPACITY(16) command (reserved bits 5-7 in the second byte are ignored).

Fixes: 7b2030942859 ("libata: Add support for SCT Write Same")
Cc: stable@vger.kernel.org
Signed-off-by: Niklas Cassel <niklas.cassel@wdc.com>
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>

scsi: core: ata: Do no try to probe for CDL on old drives

Some old drives (e.g. an Ultra320 SCSI disk as reported by John) do not
seem to execute MAINTENANCE_IN / MI_REPORT_SUPPORTED_OPERATION_CODES
commands correctly and hang when a non-zero service action is specified
(one command format with service action case in scsi_report_opcode()).

Currently, CDL probing with scsi_cdl_check_cmd() is the only caller using a
non zero service action for scsi_report_opcode(). To avoid issues with
these old drives, do not attempt CDL probe if the device reports support
for an SPC version lower than 5 (CDL was introduced in SPC-5). To keep
things working with ATA devices which probe for the CDL T2A and T2B pages
introduced with SPC-6, modify ata_scsiop_inq_std() to claim SPC-6 version
compatibility for ATA drives supporting CDL.

SPC-6 standard version number is defined as Dh (= 13) in SPC-6 r09. Fix
scsi_probe_lun() to correctly capture this value by changing the bit mask
for the second byte of the INQUIRY response from 0x7 to 0xf.
include/scsi/scsi.h is modified to add the definition SCSI_SPC_6 with the
value 14 (Dh + 1). The missing definitions for the SCSI_SPC_4 and
SCSI_SPC_5 versions are also added.

Reported-by: John David Anglin <dave.anglin@bell.net>
Fixes: 624885209f31 ("scsi: core: Detect support for command duration limits")
Cc: stable@vger.kernel.org
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Link: https://lore.kernel.org/r/20230915022034.678121-1-dlemoal@kernel.org
Tested-by: David Gow <david@davidgow.net>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Niklas Cassel <niklas.cassel@wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: core: Improve type safety of scsi_rescan_device()

Most callers of scsi_rescan_device() have the scsi_device pointer readily
available. Pass a struct scsi_device pointer to scsi_rescan_device()
instead of a struct device pointer. This change prevents that a pointer to
another struct device would be passed accidentally to scsi_rescan_device().

Remove the scsi_rescan_device() declaration from the scsi_priv.h header
file since it duplicates the declaration in <scsi/scsi_host.h>.

Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Reviewed-by: John Garry <john.g.garry@oracle.com>
Cc: Mike Christie <michael.christie@oracle.com>
Cc: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20230822153043.4046244-1-bvanassche@acm.org
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

ata: libata: remove references to non-existing error_handler()

With commit 65a15d6560df ("scsi: ipr: Remove SATA support") all
libata drivers now have the error_handler() callback provided,
so we can stop checking for non-existing error_handler callback.

Signed-off-by: Hannes Reinecke <hare@suse.de>
[niklas: fixed review comments, rebased, solved conflicts during rebase,
fixed bug that unconditionally dumped all QCs, removed the now unused
function ata_dump_status(), removed the now unreachable failure paths in
atapi_qc_complete(), removed the non-EH function to request ATAPI sense]
Signed-off-by: Niklas Cassel <niklas.cassel@wdc.com>
Reviewed-by: John Garry <john.g.garry@oracle.com>
Reviewed-by: Jason Yan <yanaijie@huawei.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>

ata: libata-scsi: fix timeout type in ata_scsi_park_store()

ata_scsi_park_store() passes its 'long input' variable (if it's >= 0) to
ata_deadline() that now takes 'unsigned int' -- eliminate unneeded implicit
cast...

Signed-off-by: Sergey Shtylyov <s.shtylyov@omp.ru>
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>

ata,scsi: do not issue START STOP UNIT on resume

During system resume, ata_port_pm_resume() triggers ata EH to
1) Resume the controller
2) Reset and rescan the ports
3) Revalidate devices
This EH execution is started asynchronously from ata_port_pm_resume(),
which means that when sd_resume() is executed, none or only part of the
above processing may have been executed. However, sd_resume() issues a
START STOP UNIT to wake up the drive from sleep mode. This command is
translated to ATA with ata_scsi_start_stop_xlat() and issued to the
device. However, depending on the state of execution of the EH process
and revalidation triggerred by ata_port_pm_resume(), two things may
happen:
1) The START STOP UNIT fails if it is received before the controller has
been reenabled at the beginning of the EH execution. This is visible
with error messages like:

ata10.00: device reported invalid CHS sector 0
sd 9:0:0:0: [sdc] Start/Stop Unit failed: Result: hostbyte=DID_OK driverbyte=DRIVER_OK
sd 9:0:0:0: [sdc] Sense Key : Illegal Request [current]
sd 9:0:0:0: [sdc] Add. Sense: Unaligned write command
sd 9:0:0:0: PM: dpm_run_callback(): scsi_bus_resume+0x0/0x90 returns -5
sd 9:0:0:0: PM: failed to resume async: error -5

2) The START STOP UNIT command is received while the EH process is
on-going, which mean that it is stopped and must wait for its
completion, at which point the command is rather useless as the drive
is already fully spun up already. This case results also in a
significant delay in sd_resume() which is observable by users as
the entire system resume completion is delayed.

Given that ATA devices will be woken up by libata activity on resume,
sd_resume() has no need to issue a START STOP UNIT command, which solves
the above mentioned problems. Do not issue this command by introducing
the new scsi_device flag no_start_on_resume and setting this flag to 1
in ata_scsi_dev_config(). sd_resume() is modified to issue a START STOP
UNIT command only if this flag is not set.

Reported-by: Paul Ausbeck <paula@soe.ucsc.edu>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=215880
Fixes: a19a93e4c6a9 ("scsi: core: pm: Rely on the device driver core for async power management")
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Tested-by: Tanner Watkins <dalzot@gmail.com>
Tested-by: Paul Ausbeck <paula@soe.ucsc.edu>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>

ata: libata-scsi: Use ata_ncq_supported in ata_scsi_dev_config()

In ata_scsi_dev_config(), instead of hard-coding the test to check if
an ATA device supports NCQ by looking at the ATA_DFLAG_NCQ flag, use
ata_ncq_supported().

Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: John Garry <john.g.garry@oracle.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>

scsi: ata: libata-scsi: Fix ata_msense_control kdoc comment

Add missing description of the spg argument of ata_msense_control().

Fixes: df60f9c64576 ("scsi: ata: libata: Add ATA feature control sub-page translation")
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Link: https://lore.kernel.org/r/20230523074701.293502-1-dlemoal@kernel.org
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Niklas Cassel <niklas.cassel@wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ata: libata: Set read/write commands CDL index

For devices supporting the command duration limits feature, translate the
dld field of read and write operation to set the command duration limit
index field of the command task file when the duration limit feature is
enabled.

The function ata_set_tf_cdl() is introduced to do this. For unqueued (non
NCQ) read and write operations, this function sets the command duration
limit index set as the lower 3 bits of the feature field. For queued NCQ
read/write commands, the index is set as the lower 3 bits of the auxiliary
field.

The flag ATA_QCFLAG_HAS_CDL is introduced to indicate that a command
taskfile has a non zero cdl field.

Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Igor Pylypiv <ipylypiv@google.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Co-developed-by: Niklas Cassel <niklas.cassel@wdc.com>
Signed-off-by: Niklas Cassel <niklas.cassel@wdc.com>
Link: https://lore.kernel.org/r/20230511011356.227789-19-nks@flawful.org
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ata: libata: Add ATA feature control sub-page translation

Add support for the ATA feature control sub-page of the control mode page
to enable/disable the command duration limits feature using the cdl_ctrl
field of the ATA feature control sub-page.

Both mode sense and mode select translation are supported. For mode sense,
the ata device flag ATA_DFLAG_CDL_ENABLED is used to cache the status of
the command duration limits feature. Enabling this feature is done using a
SET FEATURES command with a cdl action set to 1 when the page cdl_ctrl
field value is 0x2 (T2A and T2B pages supported). If this field is 0, CDL
is disabled using the SET FEATURES command with a cdl action set to 0.

Since a device CDL and NCQ priority features should not be used
simultaneously, ata_mselect_control_ata_feature() returns an error when
attempting to enable CDL with the device priority feature enabled.
Conversely, the function ata_ncq_prio_enable_store() used to enable the use
of the device NCQ priority feature through sysfs is modified to return an
error if the device CDL feature is enabled.

Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Co-developed-by: Niklas Cassel <niklas.cassel@wdc.com>
Signed-off-by: Niklas Cassel <niklas.cassel@wdc.com>
Link: https://lore.kernel.org/r/20230511011356.227789-18-nks@flawful.org
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ata: libata-scsi: Add support for CDL pages mode sense

Modify ata_scsiop_mode_sense() and ata_msense_control() to support mode
sense access to the T2A and T2B sub-pages of the control mode page.
ata_msense_control() is modified to support sub-pages. The T2A sub-page is
generated using the read descriptors of the command duration limits log
page 18h. The T2B sub-page is generated using the write descriptors of the
same log page. With the addition of these sub-pages, getting all sub-pages
of the control mode page is also supported by increasing the value of
ATA_SCSI_RBUF_SIZE from 576B up to 2048B to ensure that all sub-pages fit
in the fill buffer.

Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Co-developed-by: Niklas Cassel <niklas.cassel@wdc.com>
Signed-off-by: Niklas Cassel <niklas.cassel@wdc.com>
Link: https://lore.kernel.org/r/20230511011356.227789-17-nks@flawful.org
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ata: libata-scsi: Handle CDL bits in ata_scsiop_maint_in()

For a scsi MAINTENANCE_IN/MI_REPORT_SUPPORTED_OPERATION_CODES operation,
add the translation of the rwcdlp and cdlp bits for the READ 16 and WRITE
16 commands. If the ATA device does not support command duration limits,
these bits are always 0. If the ATA device supports command duration
limits, the rwcdlp bit is set to 1 for READ 16 and WRITE 16 and the cdlp
bits are set to 0x1 for READ 16 and 0x2 for WRITE 16. These correspond to
the T2A mode page containing the read descriptors and to the T2B mode page
containing the write descriptors, as defined in SAT-5.

Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Niklas Cassel <niklas.cassel@wdc.com>
Link: https://lore.kernel.org/r/20230511011356.227789-16-nks@flawful.org
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ata: libata: Detect support for command duration limits

Use the supported capabilities identify device data log page to detect if a
device supports the command duration limits feature. For devices supporting
this feature, set the device flag ATA_DFLAG_CDL. To support SCSI-ATA
translation, retrieve the command duration limits log page 18h and cache
this page content using the cdl array added to the ata_device data
structure.

Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Co-developed-by: Niklas Cassel <niklas.cassel@wdc.com>
Signed-off-by: Niklas Cassel <niklas.cassel@wdc.com>
Link: https://lore.kernel.org/r/20230511011356.227789-15-nks@flawful.org
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ata: libata-scsi: Remove unnecessary !cmd checks

There is no need to check if !cmd as this can only happen for ATA internal
commands which uses the ATA internal tag (32).

Most users of ata_scsi_set_sense() are from _xlat functions that translate
a scsicmd to an ATA command. These obviously have a qc->scsicmd.

ata_scsi_qc_complete() can also call ata_scsi_set_sense() via
ata_gen_passthru_sense() / ata_gen_ata_sense(), called via
ata_scsi_qc_complete(). This callback is only called for translated
commands, so it also has a qc->scsicmd.

ata_eh_analyze_ncq_error(): the NCQ error log can only contain a 0-31
value, so it will never be able to get the ATA internal tag (32).

ata_eh_request_sense(): only called by ata_eh_analyze_tf(), which is only
called when iteratating the QCs using ata_qc_for_each_raw(), which does not
include the internal tag.

Since there is no existing call site where cmd can be NULL, remove the !cmd
check from ata_scsi_set_sense() and ata_scsi_set_sense_information().

Suggested-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Niklas Cassel <niklas.cassel@wdc.com>
Link: https://lore.kernel.org/r/20230511011356.227789-13-nks@flawful.org
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

ata: libata-scsi: Avoid deadlock on rescan after device resume

When an ATA port is resumed from sleep, the port is reset and a power
management request issued to libata EH to reset the port and rescanning
the device(s) attached to the port. Device rescanning is done by
scheduling an ata_scsi_dev_rescan() work, which will execute
scsi_rescan_device().

However, scsi_rescan_device() takes the generic device lock, which is
also taken by dpm_resume() when the SCSI device is resumed as well. If
a device rescan execution starts before the completion of the SCSI
device resume, the rcu locking used to refresh the cached VPD pages of
the device, combined with the generic device locking from
scsi_rescan_device() and from dpm_resume() can cause a deadlock.

Avoid this situation by changing struct ata_port scsi_rescan_task to be
a delayed work instead of a simple work_struct. ata_scsi_dev_rescan() is
modified to check if the SCSI device associated with the ATA device that
must be rescanned is not suspended. If the SCSI device is still
suspended, ata_scsi_dev_rescan() returns early and reschedule itself for
execution after an arbitrary delay of 5ms.

Reported-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Reported-by: Joe Breuer <linux-kernel@jmbreuer.net>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=217530
Fixes: a19a93e4c6a9 ("scsi: core: pm: Rely on the device driver core for async power management")
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Tested-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Tested-by: Joe Breuer <linux-kernel@jmbreuer.net>

ata: libata-scsi: Use correct device no in ata_find_dev()

For devices not attached to a port multiplier and managed directly by
libata, the device number passed to ata_find_dev() must always be lower
than the maximum number of devices returned by ata_link_max_devices().
That is 1 for SATA devices or 2 for an IDE link with master+slave
devices. This device number is the SCSI device ID which matches these
constraints as the IDs are generated per port and so never exceed the
maximum number of devices for the link being used.

However, for libsas managed devices, SCSI device IDs are assigned per
struct scsi_host, leading to device IDs for SATA devices that can be
well in excess of libata per-link maximum number of devices. This
results in ata_find_dev() to always return NULL for libsas managed
devices except for the first device of the target scsi_host with ID
(device number) equal to 0. This issue is visible by executing the
hdparm utility, which fails. E.g.:

hdparm -i /dev/sdX
/dev/sdX:
HDIO_GET_IDENTITY failed: No message of desired type

Fix this by rewriting ata_find_dev() to ignore the device number for
non-PMP attached devices with a link with at most 1 device, that is SATA
devices. For these, the device number 0 is always used to
return the correct pointer to the struct ata_device of the port link.
This change excludes IDE master/slave setups (maximum number of devices
per link is 2) and port-multiplier attached devices. Also, to be
consistant with the fact that SCSI device IDs and channel numbers used
as device numbers are both unsigned int, change the devno argument of
ata_find_dev() to unsigned int.

Reported-by: Xingui Yang <yangxingui@huawei.com>
Fixes: 41bda9c98035 ("libata-link: update hotplug to handle PMP links")
Cc: stable@vger.kernel.org
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Jason Yan <yanaijie@huawei.com>

scsi: ata: Declare SCSI host templates const

Make it explicit that ATA host templates are not modified.

Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Reviewed-by: Serge Semin <fancer.lancer@gmail.com> (for DWC AHCI SATA)
Reviewed-by: John Garry <john.g.garry@oracle.com>
Reviewed-by: Jon Hunter <jonathanh@nvidia.com> (for Tegra)
Cc: Christoph Hellwig <hch@lst.de>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: John Garry <john.g.garry@oracle.com>
Cc: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20230322195515.1267197-5-bvanassche@acm.org
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ata: libata-scsi: Convert to scsi_execute_cmd()

scsi_execute_req() is going to be removed. Convert libata to
scsi_execute_cmd().

Signed-off-by: Mike Christie <michael.christie@oracle.com>
Reviewed-by: John Garry <john.g.garry@oracle.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Acked-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

ata: libata: cleanup fua support detection

Move the detection of a device FUA support from
ata_scsiop_mode_sense()/ata_dev_supports_fua() to device scan time in
ata_dev_configure().

The function ata_dev_config_fua() is introduced to detect if a device
supports FUA and this support is indicated using the new device flag
ATA_DFLAG_FUA.

In order to blacklist known buggy devices, the horkage flag
ATA_HORKAGE_NO_FUA is introduced. Similarly to other horkage flags, the
libata.force= arguments "fua" and "nofua" are also introduced to allow
a user to control this horkage flag through the "force" libata
module parameter.

The ATA_DFLAG_FUA device flag is set only and only if all the following
conditions are met:
* libata.fua module parameter is set to 1
* The device supports the WRITE DMA FUA EXT command,
* The device is not marked with the ATA_HORKAGE_NO_FUA flag, either from
the blacklist or set by the user with libata.force=nofua
* The device supports NCQ (while this is not mandated by the standards,
this restriction is introduced to avoid problems with older non-NCQ
devices).

Enabling or diabling libata FUA support for all devices can now also be
done using the "force=[no]fua" module parameter when libata.fua is set
to 1.

Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Niklas Cassel <niklas.cassel@wdc.com>

ata: libata-scsi: improve ata_scsiop_maint_in()

Allow translation of REPORT_SUPPORTED_OPERATION_CODES commands using
the command format 0x3, that is, checking support for commands that are
identified using an opcode and a service action.

Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Signed-off-by: Niklas Cassel <niklas.cassel@wdc.com>

ata: libata-scsi: do not overwrite SCSI ML and status bytes

For SCSI ML byte:
In the case where a command is completed via libata EH:
irq -> ata_qc_complete() -> ata_qc_schedule_eh()
irq done
... -> ata_do_eh() -> ata_eh_link_autopsy() -> ata_eh_finish() ->
ata_eh_qc_complete() -> __ata_eh_qc_complete() -> __ata_qc_complete() ->
qc->complete_fn() (ata_scsi_qc_complete()) -> ata_qc_done() ->
qc->scsidone() (empty stub)
... -> scsi_eh_finish_cmd() -> scsi_eh_flush_done_q() ->
scsi_finish_command()

ata_eh_link_autopsy() will call ata_eh_analyze_tf(), which calls
scsi_check_sense(), which sets the SCSI ML byte.

Since ata_scsi_qc_complete() is called after scsi_check_sense() when
a command is completed via libata EH, we cannot simply overwrite the
SCSI ML byte that was set earlier in the call chain.

For SCSI status byte:
When a SCSI command is prepared using scsi_prepare_cmd(), it sets
cmd->result to 0. (SAM_STAT_GOOD is defined as 0x0).
Likewise, when a command is requeued from SCSI EH, scsi_queue_insert()
is called, which sets cmd->result to 0.

A SCSI command thus always has a GOOD status by default when being
sent to libata.

If libata fetches sense data from the device, it will call
ata_scsi_set_sense(), which will set the status byte to
SAM_STAT_CHECK_CONDITION, if the caller deems that the status should be
a check condition.

ata_scsi_qc_complete() should therefore never overwrite the existing
status byte, because if it is != GOOD, it was set by libata itself,
for a reason.

For the host byte:
When libata abort commands, because of a NCQ error, it will schedule
SCSI EH for all QCs using blk_abort_request(), which will all end up in
scsi_timeout(), which will call scsi_abort_command(). scsi_timeout()
sets DID_TIME_OUT regardless if a command was aborted or timed out.
If we don't clear the DID_TIME_OUT byte for the QC that caused the
NCQ error, that QC will be reported as a timed out command, instead
of being reported as a NCQ error.

For a command that actually timed out, DID_TIME_OUT would be fine to
keep, but libata has its own way of detecting that a command timed out
(see ata_scsi_cmd_error_handler()), and sets AC_ERR_TIMEOUT if that is
the case. libata will retry timed out commands.

We could clear DID_TIME_OUT only for the QC that caused the NCQ error,
but since libata has its own way of detecting timeouts, simply clear it
always.

Note that the existing ata_scsi_qc_complete() code does:
cmd->result = SAM_STAT_CHECK_CONDITION or cmd->result = SAM_STAT_GOOD.
This WILL clear the host byte. So us clearing the host byte
unconditionally is in line with the existing libata behavior.

Signed-off-by: Niklas Cassel <niklas.cassel@wdc.com>
Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>

ata: make use of ata_port_is_frozen() helper

Clean up the code by making use of the newly introduced
ata_port_is_frozen() helper function.

Signed-off-by: Niklas Cassel <niklas.cassel@wdc.com>
Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>

ata: libata: only set sense valid flag if sense data is valid

While this shouldn't be needed if all devices that claim that they
support NCQ autosense (ata_id_has_ncq_autosense()) and/or the sense
data reporting feature (ata_id_has_sense_reporting()), actually
supported those features.

However, there might be some old ATA devices that either have these
bits set, even when they don't support those features, or they simply
return malformed data when using those features.

These devices should be quirked, but in order to try to minimize the
impact for the users of these such devices, it was suggested by Damien
Le Moal that it might be a good idea to sanity check the sense data
received from the device. If the sense data looks bogus, then the
sense data is never added to the scsi_cmnd command.

Introduce a new function, ata_scsi_sense_is_valid(), and use it in all
places where sense data is received from the device.

Suggested-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Signed-off-by: Niklas Cassel <niklas.cassel@wdc.com>
Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>

ata: libata-core: do not issue non-internal commands once EH is pending

While the ATA specification states that a device should return command
aborted for all commands queued after the device has entered error state,
since ATA only keeps the sense data for the latest command (in non-NCQ
case), we really don't want to send block layer commands to the device
after it has entered error state. (Only ATA EH commands should be sent,
to read the sense data etc.)

Currently, scsi_queue_rq() will check if scsi_host_in_recovery()
(state is SHOST_RECOVERY), and if so, it will _not_ issue a command via:
scsi_dispatch_cmd() -> host->hostt->queuecommand() (ata_scsi_queuecmd())
-> __ata_scsi_queuecmd() -> ata_scsi_translate() -> ata_qc_issue()

Before commit e494f6a72839 ("[SCSI] improved eh timeout handler"),
when receiving a TFES error IRQ, the call chain looked like this:
ahci_error_intr() -> ata_port_abort() -> ata_do_link_abort() ->
ata_qc_complete() -> ata_qc_schedule_eh() -> blk_abort_request() ->
blk_rq_timed_out() -> q->rq_timed_out_fn() (scsi_times_out()) ->
scsi_eh_scmd_add() -> scsi_host_set_state(shost, SHOST_RECOVERY)

Which meant that as soon as an error IRQ was serviced, SHOST_RECOVERY
would be set.

However, after commit e494f6a72839 ("[SCSI] improved eh timeout handler"),
scsi_times_out() will instead call scsi_abort_command() which will queue
delayed work, and the worker function scmd_eh_abort_handler() will call
scsi_eh_scmd_add(), which calls scsi_host_set_state(shost, SHOST_RECOVERY).

So now, after the TFES error IRQ has been serviced, we need to wait for
the SCSI workqueue to run its work before SHOST_RECOVERY gets set.

It is worth noting that, even before commit e494f6a72839 ("[SCSI] improved
eh timeout handler"), we could receive an error IRQ from the time when
scsi_queue_rq() checks scsi_host_in_recovery(), to the time when
ata_scsi_queuecmd() is actually called.

In order to handle both the delayed setting of SHOST_RECOVERY and the
window where we can receive an error IRQ, add a check against
ATA_PFLAG_EH_PENDING (which gets set when servicing the error IRQ),
inside ata_scsi_queuecmd() itself, while holding the ap->lock.
(Since the ap->lock is held while servicing IRQs.)

Fixes: e494f6a72839 ("[SCSI] improved eh timeout handler")
Signed-off-by: Niklas Cassel <niklas.cassel@wdc.com>
Tested-by: John Garry <john.g.garry@oracle.com>
Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>

ata: libata-scsi: fix SYNCHRONIZE CACHE (16) command failure

SAT SCSI/ATA Translation specification requires SCSI SYNCHRONIZE CACHE
(10) and (16) commands both shall be translated to ATA flush command.
Also, ZBC Zoned Block Commands specification mandates SYNCHRONIZE CACHE
(16) command support. However, libata translates only SYNCHRONIZE CACHE
(10). This results in SYNCHRONIZE CACHE (16) command failures on SATA
drives and then libata translation does not conform to ZBC. To avoid the
failure, add support for SYNCHRONIZE CACHE (16).

Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Cc: stable@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>

ata: libata-core: Simplify ata_build_rw_tf()

Since ata_build_rw_tf() is only called from ata_scsi_rw_xlat() with the
tf, dev and tag arguments obtained from the queued command structure,
we can simplify the interface of ata_build_rw_tf() by passing directly
the qc structure as argument.

Furthermore, since ata_scsi_rw_xlat() is never used for internal
commands, we can also remove the internal tag check for the NCQ case.

Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>

ata: libata-scsi: Fix initialization of device queue depth

For SATA devices supporting NCQ, drivers using libsas first initialize a
scsi device queue depth based on the controller and device capabilities,
leading to the scsi device queue_depth field being 32 (ATA maximum queue
depth) for most setup. However, if libata was loaded using the
force=[ID]]noncq argument, the default queue depth should be set to 1 to
reflect the fact that queuable commands will never be used. This is
consistent with manually setting a device queue depth to 1 through sysfs
as that disables NCQ use for the device.

Fix ata_scsi_dev_config() to honor the noncq parameter by sertting the
device queue depth to 1 for devices that do not have the ATA_DFLAG_NCQ
flag set.

Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Tested-by: John Garry <john.garry@huawei.com>

ata: libata-scsi: cap ata_device->max_sectors according to shost->max_sectors

ATA devices (struct ata_device) have a max_sectors field which is
configured internally in libata. This is then used to (re)configure the
associated sdev request queue max_sectors value from how it is earlier set
in __scsi_init_queue(). In __scsi_init_queue() the max_sectors value is set
according to shost limits, which includes host DMA mapping limits.

Cap the ata_device max_sectors according to shost->max_sectors to respect
this shost limit.

Signed-off-by: John Garry <john.garry@huawei.com>
Acked-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Acked-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

ata: libata-scsi: fix result type of ata_ioc32()

While ata_ioc32() returns 'int', its result gets assigned to and compared
with the 'unsigned long' variable 'val' in ata_sas_scsi_ioctl(), its only
caller, which implies a problematic implicit cast (with sign extension).
Fix this by returning 'bool' instead -- the implicit cast then implies
zero extension which is OK. Note that actually the object code doesn't
change because ata_ioc32() is always inlined -- I can see the expected
code changes with 'noinline'...

Found by Linux Verification Center (linuxtesting.org) with the SVACE
static analysis tool.

Signed-off-by: Sergey Shtylyov <s.shtylyov@omp.ru>
Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>

libata: fix translation of concurrent positioning ranges

Fixing the page length in the SCSI translation for the concurrent
positioning ranges VPD page. It was writing starting in offset 3
rather than offset 2 where the MSB is supposed to start for
the VPD page length.

Cc: stable@vger.kernel.org
Fixes: fe22e1c2f705 ("libata: support concurrent positioning ranges log")
Signed-off-by: Tyler Erickson <tyler.erickson@seagate.com>
Reviewed-by: Muhammad Ahmad <muhammad.ahmad@seagate.com>
Tested-by: Michael English <michael.english@seagate.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>

libata: Improve ATA queued command allocation

Improve ATA queued command allocation as follows:

- For attaining a qc tag for a SAS host we need to allocate a bit in
ata_port.sas_tag_allocated bitmap.

However we already have a unique tag per device in range
[0, ATA_MAX_QUEUE -1] in the scsi cmnd budget token, so just use that
instead.

- It is a bit pointless to have ata_qc_new_init() in libata-core.c since it
pokes scsi internals, so inline it in ata_scsi_qc_new() (in
libata-scsi.c). Also update Doc accordingly.

- Use standard SCSI helpers set_host_byte() and set_status_byte() in
ata_scsi_qc_new().

Christoph Hellwig originally contributed the change to inline
ata_qc_new_init().

Signed-off-by: John Garry <john.garry@huawei.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>

scsi: core: Remove the cmd field from struct scsi_request

Now that each scsi_request is backed by a scsi_cmnd, there is no need to
indirect the CDB storage. Change all submitters of SCSI passthrough
requests to store the CDB information directly in the scsi_cmnd, and while
doing so allocate the full 32 bytes that cover all Linux supported SCSI
hosts instead of requiring dynamic allocation for > 16 byte CDBs. On
64-bit systems this does not change the size of the scsi_cmnd at all, while
on 32-bit systems it slightly increases it for now, but that increase will
be made up by the removal of the remaining scsi_request fields.

Link: https://lore.kernel.org/r/20220224175552.988286-4-hch@lst.de
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: John Garry <john.garry@huawei.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

ata: add/use ata_taskfile::{error|status} fields

Add the explicit error and status register fields to 'struct ata_taskfile'
using the anonymous *union*s ('struct ide_taskfile' had that for ages!) and
update the libata taskfile code accordingly. There should be no object code
changes resulting from that...

Signed-off-by: Sergey Shtylyov <s.shtylyov@omp.ru>
Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>

ata: libata-scsi: use *switch* statements to check SCSI command codes

Replace strings of the *if* statements checking the SCSI command code
with the *switch* statements that fit better here...

Signed-off-by: Sergey Shtylyov <s.shtylyov@omp.ru>
Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>

ata: libata-scsi: Simplify scsi_XX_lba_len()

In scsi_10_lba_len() and scsi_16_lba_len() functions, use
get_unaligned_bexx() to access a cdb LBA and length fields instead of
hardcoding the byte retrieval. With these simplification, the functions
can also be declared inline.

Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>

ata: libata-scsi: Simplify ata_scsi_mode_select_xlat()

Use get_unaligned_be16() instead of using hardcoded accesses to
16-bits big endian cdb fields.

Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>

ata: libata-scsi: Cleanup ata_get_xlat_func()

Remove the unnecessary "break" after the return statement in the
MODE_SELECT/MODE_SELECT_10 case.

Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>

ata: libata-scsi: simplify __ata_scsi_queuecmd()

This patch cleans up the code of __ata_scsi_queuecmd(). Since each
branch of the "if" condition check that scmd->cmd_len is not zero, move
this check out of the "if" to simplify the conditions being checked in
the "else" branch.

While at it, avoid the if-else-if-else structure using if-else if
structure and remove the redundant rc local variable.

This patch does not change the function logic.

Signed-off-by: Wenchao Hao <haowenchao@huawei.com>
Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>

ata: libata-scsi: rework ata_dump_status to avoid using pr_cont()

pr_cont() has the problem that individual calls will be disrupted
under high load, causing each call to end up on a single line and
thereby mangling the output.
So rework ata_dump_status() to have just one call to ata_port_warn()
and avoid this problem.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>

ata: libata: remove pointless VPRINTK() calls

Most of the information is already covered by tracepoints
(if not downright pointless), so remove the VPRINTK() calls.
And while we're at it, remove ata_scsi_dump_cdb(), too,
as this information can be retrieved from scsi tracing.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>

ata: libata-scsi: drop DPRINTK calls for cdb translation

Drop DPRINTK calls for cdb translation as they are already covered
by other traces, and also drop the DPRINTK calls in ata_scsi_hotplug().

Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>

ata: libata: use min() to make code cleaner

Use min() in order to make code cleaner.

Reported-by: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: Changcheng Deng <deng.changcheng@zte.com.cn>
Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>

ata: libata-scsi: use sysfs_emit()

Use sysfs_emit() instead of snprintf() in ata_scsi_park_show().

Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>

libata: if T_LENGTH is zero, dma direction should be DMA_NONE

Avoid data corruption by rejecting pass-through commands where
T_LENGTH is zero (No data is transferred) and the dma direction
is not DMA_NONE.

Cc: <stable@vger.kernel.org>
Reported-by: syzkaller<syzkaller@googlegroups.com>
Signed-off-by: George Kennedy<george.kennedy@oracle.com>
Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>

scsi: ata: Switch to attribute groups

struct device supports attribute groups directly but does not support
struct device_attribute directly. Hence switch to attribute groups.

Link: https://lore.kernel.org/r/20211012233558.4066756-3-bvanassche@acm.org
Acked-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: ata: Call scsi_done() directly

Conditional statements are faster than indirect calls. Hence call
scsi_done() directly.

Link: https://lore.kernel.org/r/20211007202923.2174984-4-bvanassche@acm.org
Acked-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

libata-scsi: fix checking of DMA state

Checking if DMA is enabled should be done via the
ata_dma_enabled helper function, since the init state
0xff indicates disabled.
Change based on code review, not tested due to lack of hardware.

Signed-off-by: Reimar Döffinger <Reimar.Doeffinger@gmx.de>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>

libata: support concurrent positioning ranges log

Add support to discover if an ATA device supports the Concurrent
Positioning Ranges data log (address 0x47), indicating that the device
is capable of seeking to multiple different locations in parallel using
multiple actuators serving different LBA ranges.

Also add support to translate the concurrent positioning ranges log
into its equivalent Concurrent Positioning Ranges VPD page B9h in
libata-scsi.c.

The format of the Concurrent Positioning Ranges Log is defined in ACS-5
r9.

Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Link: https://lore.kernel.org/r/20211027022223.183838-4-damien.lemoal@wdc.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

scsi: ata: Use scsi_cmd_to_rq() instead of scsi_cmnd.request

Prepare for removal of the request pointer by using scsi_cmd_to_rq()
instead. This patch does not change any functionality.

Link: https://lore.kernel.org/r/20210809230355.8186-8-bvanassche@acm.org
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

libata: simplify ata_scsi_rbuf_fill()

Sparse complains about context imbalance in ata_scsi_rbuf_get() and
ata_scsi_rbuf_put() due to these functions respectively only taking
and releasing the ata_scsi_rbuf_lock spinlock. Since these functions are
only called from ata_scsi_rbuf_fill() with ata_scsi_rbuf_get() being
called with a copy_in argument always false, the code can be simplified
and ata_scsi_rbuf_{get|put} removed. This change both simplifies the
code and fixes the sparse warning.

Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Link: https://lore.kernel.org/r/20210816014456.2191776-4-damien.lemoal@wdc.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

scsi: core: Drop obsolete Linux-specific SCSI status codes

Originally the SCSI subsystem has been using 'special' SCSI status codes,
which were the SAM-specified ones but shifted by 1. As most drivers have
now been modified to use the SAM-specified ones, having two nearly
identical sets of definitions only causes confusion.

The Linux-specifed SCSI status codes have been marked obsolete for several
years so drop them and use the SAM-specified status codes throughout.

Link: https://lore.kernel.org/r/20210427083046.31620-41-hare@suse.de
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: core: Kill DRIVER_SENSE

Replace the check for DRIVER_SENSE with a check for
scsi_status_is_check_condition().

Audit all callsites to ensure the SAM status is set correctly. For
backwards compability move the DRIVER_SENSE definition to sg.h, and update
sg, bsg, and scsi_ioctl to set the DRIVER_SENSE driver_status whenever
SAM_STAT_CHECK_CONDITION is present.

[mkp: fix zeroday srp warning]

Link: https://lore.kernel.org/r/20210427083046.31620-10-hare@suse.de
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

fix

scsi: core: Introduce scsi_build_sense()

Introduce scsi_build_sense() as a wrapper around scsi_build_sense_buffer()
to format the buffer and set the correct SCSI status.

Link: https://lore.kernel.org/r/20210427083046.31620-8-hare@suse.de
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: core: Stop using DRIVER_ERROR

Return the actual error code in __scsi_execute() (which, according to the
documentation, should have happened anyway). And audit all callers to cope
with negative return values from __scsi_execute() and friends.

[mkp: resolve conflict and return bool]

Link: https://lore.kernel.org/r/20210427083046.31620-7-hare@suse.de
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

block: remove BLK_BOUNCE_ISA support

Remove the BLK_BOUNCE_ISA support now that all users are gone.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Link: https://lore.kernel.org/r/20210331073001.46776-7-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

ata: fix some kernel-doc markups

Some functions have different names between their prototypes
and the kernel-doc markup.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

libata: implement ATA_HORKAGE_MAX_TRIM_128M and apply to Sandisks

All three generations of Sandisk SSDs lock up hard intermittently.
Experiments showed that disabling NCQ lowered the failure rate significantly
and the kernel has been disabling NCQ for some models of SD7's and 8's,
which is obviously undesirable.

Karthik worked with Sandisk to root cause the hard lockups to trim commands
larger than 128M. This patch implements ATA_HORKAGE_MAX_TRIM_128M which
limits max trim size to 128M and applies it to all three generations of
Sandisk SSDs.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Karthik Shivaram <karthikgs@fb.com>
Cc: stable@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>

treewide: Use fallthrough pseudo-keyword

Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through markings when it is the case.

[1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>

treewide: Remove uninitialized_var() usage

Using uninitialized_var() is dangerous as it papers over real bugs[1]
(or can in the future), and suppresses unrelated compiler warnings
(e.g. "unused variable"). If the compiler thinks it is uninitialized,
either simply initialize the variable or make compiler changes.

In preparation for removing[2] the[3] macro[4], remove all remaining
needless uses with the following script:

git grep '\buninitialized_var\b' | cut -d: -f1 | sort -u | \
xargs perl -pi -e \
's/\buninitialized_var\(([^\)]+)\)/\1/g;
s:\s*/\* (GCC be quiet|to make compiler happy) \*/$::g;'

drivers/video/fbdev/riva/riva_hw.c was manually tweaked to avoid
pathological white-space.

No outstanding warnings were found building allmodconfig with GCC 9.3.0
for x86_64, i386, arm64, arm, powerpc, powerpc64le, s390x, mips, sparc64,
alpha, and m68k.

[1] https://lore.kernel.org/lkml/20200603174714.192027-1-glider@google.com/
[2] https://lore.kernel.org/lkml/CA+55aFw+Vbj0i=1TGqCR5vQkCzWJ0QxK6CernOU6eedsudAixw@mail.gmail.com/
[3] https://lore.kernel.org/lkml/CA+55aFwgbgqhbp1fkxvRKEpzyR5J8n1vKT1VZdz9knmPuXhOeg@mail.gmail.com/
[4] https://lore.kernel.org/lkml/CA+55aFz2500WfbKXAx8s67wrm9=yVJu65TpLgN_ybYNv0VEOKA@mail.gmail.com/

Reviewed-by: Leon Romanovsky <leonro@mellanox.com> # drivers/infiniband and mlx4/mlx5
Acked-by: Jason Gunthorpe <jgg@mellanox.com> # IB
Acked-by: Kalle Valo <kvalo@codeaurora.org> # wireless drivers
Reviewed-by: Chao Yu <yuchao0@huawei.com> # erofs
Signed-off-by: Kees Cook <keescook@chromium.org>

ata/libata: Fix usage of page address by page_address in ata_scsi_mode_select_xlat function

BUG: KASAN: use-after-free in ata_scsi_mode_select_xlat+0x10bd/0x10f0
drivers/ata/libata-scsi.c:4045
Read of size 1 at addr ffff88803b8cd003 by task syz-executor.6/12621

CPU: 1 PID: 12621 Comm: syz-executor.6 Not tainted 4.19.95 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
1.10.2-1ubuntu1 04/01/2014
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0xac/0xee lib/dump_stack.c:118
print_address_description+0x60/0x223 mm/kasan/report.c:253
kasan_report_error mm/kasan/report.c:351 [inline]
kasan_report mm/kasan/report.c:409 [inline]
kasan_report.cold+0xae/0x2d8 mm/kasan/report.c:393
ata_scsi_mode_select_xlat+0x10bd/0x10f0 drivers/ata/libata-scsi.c:4045
ata_scsi_translate+0x2da/0x680 drivers/ata/libata-scsi.c:2035
__ata_scsi_queuecmd drivers/ata/libata-scsi.c:4360 [inline]
ata_scsi_queuecmd+0x2e4/0x790 drivers/ata/libata-scsi.c:4409
scsi_dispatch_cmd+0x2ee/0x6c0 drivers/scsi/scsi_lib.c:1867
scsi_queue_rq+0xfd7/0x1990 drivers/scsi/scsi_lib.c:2170
blk_mq_dispatch_rq_list+0x1e1/0x19a0 block/blk-mq.c:1186
blk_mq_do_dispatch_sched+0x147/0x3d0 block/blk-mq-sched.c:108
blk_mq_sched_dispatch_requests+0x427/0x680 block/blk-mq-sched.c:204
__blk_mq_run_hw_queue+0xbc/0x200 block/blk-mq.c:1308
__blk_mq_delay_run_hw_queue+0x3c0/0x460 block/blk-mq.c:1376
blk_mq_run_hw_queue+0x152/0x310 block/blk-mq.c:1413
blk_mq_sched_insert_request+0x337/0x6c0 block/blk-mq-sched.c:397
blk_execute_rq_nowait+0x124/0x320 block/blk-exec.c:64
blk_execute_rq+0xc5/0x112 block/blk-exec.c:101
sg_scsi_ioctl+0x3b0/0x6a0 block/scsi_ioctl.c:507
sg_ioctl+0xd37/0x23f0 drivers/scsi/sg.c:1106
vfs_ioctl fs/ioctl.c:46 [inline]
file_ioctl fs/ioctl.c:501 [inline]
do_vfs_ioctl+0xae6/0x1030 fs/ioctl.c:688
ksys_ioctl+0x76/0xa0 fs/ioctl.c:705
__do_sys_ioctl fs/ioctl.c:712 [inline]
__se_sys_ioctl fs/ioctl.c:710 [inline]
__x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:710
do_syscall_64+0xa0/0x2e0 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45c479
Code: ad b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89
f7 48
89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff
ff 0f
83 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fb0e9602c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fb0e96036d4 RCX: 000000000045c479
RDX: 0000000020000040 RSI: 0000000000000001 RDI: 0000000000000003
RBP: 000000000076bfc0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 000000000000046d R14: 00000000004c6e1a R15: 000000000076bfcc

Allocated by task 12577:
set_track mm/kasan/kasan.c:460 [inline]
kasan_kmalloc mm/kasan/kasan.c:553 [inline]
kasan_kmalloc+0xbf/0xe0 mm/kasan/kasan.c:531
__kmalloc+0xf3/0x1e0 mm/slub.c:3749
kmalloc include/linux/slab.h:520 [inline]
load_elf_phdrs+0x118/0x1b0 fs/binfmt_elf.c:441
load_elf_binary+0x2de/0x4610 fs/binfmt_elf.c:737
search_binary_handler fs/exec.c:1654 [inline]
search_binary_handler+0x15c/0x4e0 fs/exec.c:1632
exec_binprm fs/exec.c:1696 [inline]
__do_execve_file.isra.0+0xf52/0x1a90 fs/exec.c:1820
do_execveat_common fs/exec.c:1866 [inline]
do_execve fs/exec.c:1883 [inline]
__do_sys_execve fs/exec.c:1964 [inline]
__se_sys_execve fs/exec.c:1959 [inline]
__x64_sys_execve+0x8a/0xb0 fs/exec.c:1959
do_syscall_64+0xa0/0x2e0 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x44/0xa9

Freed by task 12577:
set_track mm/kasan/kasan.c:460 [inline]
__kasan_slab_free+0x129/0x170 mm/kasan/kasan.c:521
slab_free_hook mm/slub.c:1370 [inline]
slab_free_freelist_hook mm/slub.c:1397 [inline]
slab_free mm/slub.c:2952 [inline]
kfree+0x8b/0x1a0 mm/slub.c:3904
load_elf_binary+0x1be7/0x4610 fs/binfmt_elf.c:1118
search_binary_handler fs/exec.c:1654 [inline]
search_binary_handler+0x15c/0x4e0 fs/exec.c:1632
exec_binprm fs/exec.c:1696 [inline]
__do_execve_file.isra.0+0xf52/0x1a90 fs/exec.c:1820
do_execveat_common fs/exec.c:1866 [inline]
do_execve fs/exec.c:1883 [inline]
__do_sys_execve fs/exec.c:1964 [inline]
__se_sys_execve fs/exec.c:1959 [inline]
__x64_sys_execve+0x8a/0xb0 fs/exec.c:1959
do_syscall_64+0xa0/0x2e0 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x44/0xa9

The buggy address belongs to the object at ffff88803b8ccf00
which belongs to the cache kmalloc-512 of size 512
The buggy address is located 259 bytes inside of
512-byte region [ffff88803b8ccf00, ffff88803b8cd100)
The buggy address belongs to the page:
page:ffffea0000ee3300 count:1 mapcount:0 mapping:ffff88806cc03080
index:0xffff88803b8cc780 compound_mapcount: 0
flags: 0x100000000008100(slab|head)
raw: 0100000000008100 ffffea0001104080 0000000200000002 ffff88806cc03080
raw: ffff88803b8cc780 00000000800c000b 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
ffff88803b8ccf00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff88803b8ccf80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88803b8cd000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff88803b8cd080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff88803b8cd100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc

You can refer to "https://www.lkml.org/lkml/2019/1/17/474" reproduce
this error.

The exception code is "bd_len = p[3];", "p" value is ffff88803b8cd000
which belongs to the cache kmalloc-512 of size 512. The "page_address(sg_page(scsi_sglist(scmd)))"
maybe from sg_scsi_ioctl function "buffer" which allocated by kzalloc, so "buffer"
may not page aligned.
This also looks completely buggy on highmem systems and really needs to use a
kmap_atomic. --Christoph Hellwig
To address above bugs, Paolo Bonzini advise to simpler to just make a char array
of size CACHE_MPAGE_LEN+8+8+4-2(or just 64 to make it easy), use sg_copy_to_buffer
to copy from the sglist into the buffer, and workthere.

Signed-off-by: Ye Bin <yebin10@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: move dma_pad handling from blk_rq_map_sg into the callers

There are only two callers of blk_rq_map_sg/__blk_rq_map_sg that set
the dma_pad value in the queue. Move the handling into those callers
instead of burdening the common code, and move the ->extra_len field
from struct request to struct scsi_cmnd.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: move dma drain handling to scsi

Don't burden the common block code with with specifics of the libata DMA
draining mechanism. Instead move most of the code to the scsi midlayer.

That also means the nr_phys_segments adjustments in the blk-mq fast path
can go away entirely, given that SCSI never looks at nr_phys_segments
after mapping the request to a scatterlist.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

ata: move ata_sas_*() to libata-sata.c

* un-inline:
- ata_scsi_dump_cdb()
- __ata_scsi_queuecmd()

* un-static:
- ata_scsi_sdev_config()
- ata_scsi_dev_config()
- ata_scsi_dump_cdb()
- __ata_scsi_queuecmd()

* move ata_sas_*() to libata-sata.c:

* add static inlines for CONFIG_SATA_HOST=n case for
ata_sas_{allocate,free}_tag()

Code size savings on m68k arch using (modified) atari_defconfig:

text data bss dec hex filename
before:
19137 23 576 19736 4d18 drivers/ata/libata-scsi.o
after:
18330 23 576 18929 49f1 drivers/ata/libata-scsi.o

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

ata: start separating SATA specific code from libata-scsi.c

Start separating SATA specific code from libata-scsi.c:

* un-static ata_scsi_find_dev()

* move following code to libata-sata.c:
- SATA only sysfs device attributes handling
- __ata_change_queue_depth()
- ata_scsi_change_queue_depth()

* cover with CONFIG_SATA_HOST ifdef SATA only sysfs device
attributes handling code and ATA_SHT_NCQ() macro in
<linux/libata.h>

Code size savings on m68k arch using (modified) atari_defconfig:

text data bss dec hex filename
before:
20702 105 576 21383 5387 drivers/ata/libata-scsi.o
after:
19137 23 576 19736 4d18 drivers/ata/libata-scsi.o

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

ata: remove EXPORT_SYMBOL_GPL()s not used by modules

Remove EXPORT_SYMBOL_GPL()s for functions used only by
the core libata code.

Code size savings on m68k arch using (modified) atari_defconfig:

text data bss dec hex filename
before:
39838 573 40 40451 9e03 drivers/ata/libata-core.o
21071 105 576 21752 54f8 drivers/ata/libata-scsi.o
17519 18 0 17537 4481 drivers/ata/libata-eh.o
after:
39688 573 40 40301 9d6d drivers/ata/libata-core.o
21040 105 576 21721 54d9 drivers/ata/libata-scsi.o
17405 18 0 17423 440f drivers/ata/libata-eh.o

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

ata: move EXPORT_SYMBOL_GPL()s close to exported code

Move EXPORT_SYMBOL_GPL()s close to exported code like it is
done in other kernel subsystems. As a nice side effect this
results in the removal of few ifdefs.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

ata: optimize ata_scsi_rbuf[] size

Currently the maximum required size of the ata_scsi_rbuf[] is
576 bytes in ata_scsiop_inq_89() so modify ATA_SCSI_RBUF_SIZE
define accordingly.

Code size savings on m68k arch using (modified) atari_defconfig:

text data bss dec hex filename
before:
20782 105 4096 24983 6197 drivers/ata/libata-scsi.o
after:
20782 105 576 21463 53d7 drivers/ata/libata-scsi.o

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

ata: simplify ata_scsiop_inq_89()

Initialize rbuf[] directly instead of using ata_tf_to_fis(). This
results in simpler and smaller code. It also allows separating
ata_tf_to_fis() into SATA specific libata part in the future.

Code size savings on m68k arch using (modified) atari_defconfig:

text data bss dec hex filename
before:
20824 105 4096 25025 61c1 drivers/ata/libata-scsi.o
after:
20782 105 4096 24983 6197 drivers/ata/libata-scsi.o

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

ata: expose ncq_enable_prio sysfs attribute only on NCQ capable hosts

There is no point in exposing ncq_enable_prio sysfs attribute for
devices on PATA and non-NCQ capable SATA hosts so:

* remove dev_attr_ncq_prio_enable from ata_common_sdev_attrs[]

* add ata_ncq_sdev_attrs[]

* update ATA_NCQ_SHT() macro to use ata_ncq_sdev_attrs[]

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

ata: remove stale maintainership information from core code

In commit 7634ccd2da97 ("libata: maintainership update") from 2018
Jens has officially taken over libata maintainership from Tejun so
remove stale information from core libata code.

Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

libata: Assign OF node to the SCSI device

When we spawn a SCSI device from an ATA device in libata-scsi
the SCSI device had no relation to the device tree.

The DT binding allows us to define port nodes under a
PATA (IDE) or SATA host controller, so we can have proper device
nodes for these devices.

If OF is enabled, walk the children of the host controller node
to see if there is a valid device tree node to assign. The reg
is used to match to ID 0 for the master device and ID 1 for the
slave device.

The corresponding device tree bindings have been accepted by
the device tree maintainers.

Cc: Chris Healy <cphealy@gmail.com>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

libata: Remove extra scsi_host_put() in ata_scsi_add_hosts()

If the call to scsi_add_host_with_dma() in ata_scsi_add_hosts() fails,
then we may get use-after-free KASAN warns:

==================================================================
BUG: KASAN: use-after-free in kobject_put+0x24/0x180
Read of size 1 at addr ffff0026b8c80364 by task swapper/0/1
CPU: 1 PID: 1 Comm: swapper/0 Tainted: G W 5.6.0-rc3-00004-g5a71b206ea82-dirty #1765
Hardware name: Huawei TaiShan 200 (Model 2280)/BC82AMDD, BIOS 2280-V2 CS V3.B160.01 02/24/2020
Call trace:
dump_backtrace+0x0/0x298
show_stack+0x14/0x20
dump_stack+0x118/0x190
print_address_description.isra.9+0x6c/0x3b8
__kasan_report+0x134/0x23c
kasan_report+0xc/0x18
__asan_load1+0x5c/0x68
kobject_put+0x24/0x180
put_device+0x10/0x20
scsi_host_put+0x10/0x18
ata_devres_release+0x74/0xb0
release_nodes+0x2d0/0x470
devres_release_all+0x50/0x78
really_probe+0x2d4/0x560
driver_probe_device+0x7c/0x148
device_driver_attach+0x94/0xa0
__driver_attach+0xa8/0x110
bus_for_each_dev+0xe8/0x158
driver_attach+0x30/0x40
bus_add_driver+0x220/0x2e0
driver_register+0xbc/0x1d0
__pci_register_driver+0xbc/0xd0
ahci_pci_driver_init+0x20/0x28
do_one_initcall+0xf0/0x608
kernel_init_freeable+0x31c/0x384
kernel_init+0x10/0x118
ret_from_fork+0x10/0x18

Allocated by task 5:
save_stack+0x28/0xc8
__kasan_kmalloc.isra.8+0xbc/0xd8
kasan_kmalloc+0xc/0x18
__kmalloc+0x1a8/0x280
scsi_host_alloc+0x44/0x678
ata_scsi_add_hosts+0x74/0x268
ata_host_register+0x228/0x488
ahci_host_activate+0x1c4/0x2a8
ahci_init_one+0xd18/0x1298
local_pci_probe+0x74/0xf0
work_for_cpu_fn+0x2c/0x48
process_one_work+0x488/0xc08
worker_thread+0x330/0x5d0
kthread+0x1c8/0x1d0
ret_from_fork+0x10/0x18

Freed by task 5:
save_stack+0x28/0xc8
__kasan_slab_free+0x118/0x180
kasan_slab_free+0x10/0x18
slab_free_freelist_hook+0xa4/0x1a0
kfree+0xd4/0x3a0
scsi_host_dev_release+0x100/0x148
device_release+0x7c/0xe0
kobject_put+0xb0/0x180
put_device+0x10/0x20
scsi_host_put+0x10/0x18
ata_scsi_add_hosts+0x210/0x268
ata_host_register+0x228/0x488
ahci_host_activate+0x1c4/0x2a8
ahci_init_one+0xd18/0x1298
local_pci_probe+0x74/0xf0
work_for_cpu_fn+0x2c/0x48
process_one_work+0x488/0xc08
worker_thread+0x330/0x5d0
kthread+0x1c8/0x1d0
ret_from_fork+0x10/0x18

There is also refcount issue, as well:
WARNING: CPU: 1 PID: 1 at lib/refcount.c:28 refcount_warn_saturate+0xf8/0x170

The issue is that we make an erroneous extra call to scsi_host_put()
for that host:

So in ahci_init_one()->ata_host_alloc_pinfo()->ata_host_alloc(), we setup
a device release method - ata_devres_release() - which intends to release
the SCSI hosts:

static void ata_devres_release(struct device *gendev, void *res)
{
...
for (i = 0; i < host->n_ports; i++) {
struct ata_port *ap = host->ports[i];

if (!ap)
continue;

if (ap->scsi_host)
scsi_host_put(ap->scsi_host);

}
...
}

However in the ata_scsi_add_hosts() error path, we also call
scsi_host_put() for the SCSI hosts.

Fix by removing the the scsi_host_put() calls in ata_scsi_add_hosts() and
leave this to ata_devres_release().

Fixes: f31871951b38 ("libata: separate out ata_host_alloc() and ata_host_register()")
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

compat_ioctl: scsi: handle HDIO commands from drivers

The ata_sas_scsi_ioctl() function implements a number of HDIO_* commands
for SCSI devices, it is used by all libata drivers as well as a few
drivers that support SAS attached SATA drives.

The only command that is not safe for compat ioctls here is
HDIO_GET_32BIT. Change the implementation to check for in_compat_syscall()
in order to do both cases correctly, and change all callers to use it
as both native and compat callback pointers, including the indirect
callers through sas_ioctl and ata_scsi_ioctl.

Reviewed-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

Revert "libata, freezer: avoid block device removal while system is frozen"

This reverts commit 85fbd722ad0f5d64d1ad15888cd1eb2188bfb557.

The commit was added as a quick band-aid for a hang that happened when a
block device was removed during system suspend. Now that bdi_wq is not
freezable anymore the hang should not be possible and we can get rid of
this hack by reverting it.

Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

libata: have ata_scsi_rw_xlat() fail invalid passthrough requests

For passthrough requests, libata-scsi takes what the user passes in
as gospel. This can be problematic if the user fills in the CDB
incorrectly. One example of that is in request sizes. For read/write
commands, the CDB contains fields describing the transfer length of
the request. These should match with the SG_IO header fields, but
libata-scsi currently does no validation of that.

Check that the number of blocks in the CDB for passthrough requests
matches what was mapped into the request. If the CDB asks for more
data then the validated SG_IO header fields, error it.

Reported-by: Krishna Ram Prakash R <krp@gtux.in>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 18

Based on 1 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 or at your option any
later version this program is distributed in the hope that it will
be useful but without any warranty without even the implied warranty
of merchantability or fitness for a particular purpose see the gnu
general public license for more details you should have received a
copy of the gnu general public license along with this program see
the file copying if not write to the free software foundation 675
mass ave cambridge ma 02139 usa

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 52 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Jilayne Lovejoy <opensource@jilayne.com>
Reviewed-by: Steve Winslow <swinslow@gmail.com>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190519154042.342335923@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

libata: fix a typo in comment

poitner -> pointer.

Signed-off-by: Chengguang Xu <cgxu519@gmx.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block: kill QUEUE_FLAG_FLUSH_NQ

We have various helpers for setting/clearing this flag, and also
a helper to check if the queue supports queueable flushes or not.
But nobody uses them anymore, kill it with fire.

Signed-off-by: Jens Axboe <axboe@kernel.dk>

scsi: ata: Use unsigned int for cmd's type in ioctls in scsi_host_template

Clang warns several times in the scsi subsystem (trimmed for brevity):

drivers/scsi/hpsa.c:6209:7: warning: overflow converting case value to
switch condition type (2147762695 to 18446744071562347015) [-Wswitch]
case CCISS_GETBUSTYPES:
^
drivers/scsi/hpsa.c:6208:7: warning: overflow converting case value to
switch condition type (2147762694 to 18446744071562347014) [-Wswitch]
case CCISS_GETHEARTBEAT:
^

The root cause is that the _IOC macro can generate really large numbers,
which don't fit into type 'int', which is used for the cmd parameter in
the ioctls in scsi_host_template. My research into how GCC and Clang are
handling this at a low level didn't prove fruitful. However, looking at
the rest of the kernel tree, all ioctls use an 'unsigned int' for the
cmd parameter, which will fit all of the _IOC values in the scsi/ata
subsystems.

Make that change because none of the ioctls expect a negative value for
any command, it brings the ioctls inline with the reset of the kernel,
and it removes ambiguity, which is never good when dealing with compilers.

Link: https://github.com/ClangBuiltLinux/linux/issues/85
Link: https://github.com/ClangBuiltLinux/linux/issues/154
Link: https://github.com/ClangBuiltLinux/linux/issues/157
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Acked-by: Bradley Grove <bgrove@attotech.com>
Acked-by: Don Brace <don.brace@microsemi.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

libata: Use SMART LBAM/LBAH password defines

Instead of hardcoding magic values for the SMART password,
use the defines in <linux/ata.h>

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

libata-scsi: Move sense buffers onto stack

To support future compile-time sizeof() checks that will be able to
validate the length of sense buffers, this removes the only dynamically
allocated sense buffers in the tree by putting the 96 byte sense buffers
on the stack.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

ata: ahci: Support state with min power but Partial low power state

Currently when min_power policy is selected, the partial low power state
is not entered and link will try aggressively enter to only slumber state.
Add a new policy which still enable DEVSLP but also try to enter partial
low power state. This policy is presented as "min_power_with_partial".

For information the difference between partial and slumber
Partial – PHY logic is powered up, and in a reduced power state. The link
PM exit latency to active state maximum is 10 ns.
Slumber – PHY logic is powered up, and in a reduced power state. The link
PM exit latency to active state maximum is 10 ms.
Devslp – PHY logic is powered down. The link PM exit latency from this
state to active state maximum is 20 ms, unless otherwise specified by
DETO.

Suggested-and-reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

ata: Guard ata_scsi_dump_cdb() by ATA_VERBOSE_DEBUG

Defining `ATA_DEBUG` nothing can be really seen, as the log is spammed
with CDB messages.

Therefore, guard the print by `ATA_VERBOSE_DEBUG`.

Signed-off-by: Paul Menzel <pmenzel@molgen.mpg.de>
Signed-off-by: Tejun Heo <tj@kernel.org>

ata: Fix ZBC_OUT all bit handling

If the ALL bit is set in the ZBC_OUT command, the command zone ID field
(block) should be ignored.

Reported-by: David Butterfield <david.butterfield@wdc.com>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Cc: stable@vger.kernel.org
Signed-off-by: Tejun Heo <tj@kernel.org>

ata: Fix ZBC_OUT command block check

The block (LBA) specified must not exceed the last addressable LBA,
which is dev->nr_sectors - 1. So fix the correct check is
"if (block >= dev->n_sectors)" and not "if (block > dev->n_sectords)".

Additionally, the asc/ascq to return for an LBA that is not a zone start
LBA should be ILLEGAL REQUEST, regardless if the bad LBA is out of
range.

Reported-by: David Butterfield <david.butterfield@wdc.com>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Cc: stable@vger.kernel.org
Signed-off-by: Tejun Heo <tj@kernel.org>

libata: don't clamp queue depth to ATA_MAX_QUEUE - 1

Use what the driver provides, which will still be ATA_MAX_QUEUE - 1
at most anyway.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Tejun Heo <tj@kernel.org>

libata: use ata_tag_internal() consistently

Some check for the value directly, use the provided helper instead.
Also make it return a bool, since that's what it does.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Tejun Heo <tj@kernel.org>

libata: convert core and drivers to ->hw_tag usage

Anything that goes to the hardware should use ->hw_tag, anything
related to internal lookup should be using ->tag.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Tejun Heo <tj@kernel.org>

libata: Honor RQF_QUIET flag

Currently, libata ignores requests RQF_QUIET flag and print error
messages for failed commands, regardless if this flag is set in the
command request. Fix this by introducing the ata_eh_quiet() function and
using this function in ata_eh_link_autopsy() to determine if the EH
context should be quiet. This works by counting the number of failed
commands and the number of commands with the quiet flag set. If both
numbers are equal, the the EH context can be set to quiet and all error
messages suppressed. Otherwise, only the error messages for the failed
commands are suppressed and the link Emask and irq_stat messages printed.

Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

scsi: libsas: add transport class for ATA devices

Now ata devices attached with sas controller do not have transport
class, so that we can not see any information of these ata devices in
/sys/class/ata_port(or ata_link or ata_device).

Add transport class for the ata devices attached with sas controller.
The /sys/class directory will show the infomation of the ata devices
as follows:

localhost:/sys/class # ls ata*
ata_device:
dev1.0 dev2.0

ata_link:
link1 link2

ata_port:
ata1 ata2

No functional change of the device scanning and io path. The ata
transport class was deleted when destroying the sas devices.

Signed-off-by: Jason Yan <yanaijie@huawei.com>
CC: Dan Williams <dan.j.williams@intel.com>
CC: Tejun Heo <tj@kernel.org>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

libata: don't try to pass through NCQ commands to non-NCQ devices

syzkaller hit a WARN() in ata_bmdma_qc_issue() when writing to /dev/sg0.
This happened because it issued an ATA pass-through command (ATA_16)
where the protocol field indicated that NCQ should be used -- but the
device did not support NCQ.

We could just remove the WARN() from libata-sff.c, but the real problem
seems to be that the SCSI -> ATA translation code passes through NCQ
commands without verifying that the device actually supports NCQ.

Fix this by adding the appropriate check to ata_scsi_pass_thru().

Here's reproducer that works in QEMU when /dev/sg0 refers to a disk of
the default type ("82371SB PIIX3 IDE"):

#include <fcntl.h>
#include <unistd.h>

int main()
{
char buf[53] = { 0 };

buf[36] = 0x85; /* ATA_16 */
buf[37] = (12 << 1); /* FPDMA */
buf[38] = 0x1; /* Has data */
buf[51] = 0xC8; /* ATA_CMD_READ */
write(open("/dev/sg0", O_RDWR), buf, sizeof(buf));
}

Fixes: ee7fb331c3ac ("libata: add support for NCQ commands for SG interface")
Reported-by: syzbot+2f69ca28df61bdfc77cd36af2e789850355a221e@syzkaller.appspotmail.com
Cc: <stable@vger.kernel.org> # v4.4+
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

libata: fix length validation of ATAPI-relayed SCSI commands

syzkaller reported a crash in ata_bmdma_fill_sg() when writing to
/dev/sg1. The immediate cause was that the ATA command's scatterlist
was not DMA-mapped, which causes 'pi - 1' to underflow, resulting in a
write to 'qc->ap->bmdma_prd[0xffffffff]'.

Strangely though, the flag ATA_QCFLAG_DMAMAP was set in qc->flags. The
root cause is that when __ata_scsi_queuecmd() is preparing to relay a
SCSI command to an ATAPI device, it doesn't correctly validate the CDB
length before copying it into the 16-byte buffer 'cdb' in 'struct
ata_queued_cmd'. Namely, it validates the fixed CDB length expected
based on the SCSI opcode but not the actual CDB length, which can be
larger due to the use of the SG_NEXT_CMD_LEN ioctl. Since 'flags' is
the next member in ata_queued_cmd, a buffer overflow corrupts it.

Fix it by requiring that the actual CDB length be <= 16 (ATAPI_CDB_LEN).

[Really it seems the length should be required to be <= dev->cdb_len,
but the current behavior seems to have been intentionally introduced by
commit 607126c2a21c ("libata-scsi: be tolerant of 12-byte ATAPI commands
in 16-byte CDBs") to work around a userspace bug in mplayer. Probably
the workaround is no longer needed (mplayer was fixed in 2007), but
continuing to allow lengths to up 16 appears harmless for now.]

Here's a reproducer that works in QEMU when /dev/sg1 refers to the
CD-ROM drive that qemu-system-x86_64 creates by default:

#include <fcntl.h>
#include <sys/ioctl.h>
#include <unistd.h>

#define SG_NEXT_CMD_LEN 0x2283

int main()
{
char buf[53] = { [36] = 0x7e, [52] = 0x02 };
int fd = open("/dev/sg1", O_RDWR);
ioctl(fd, SG_NEXT_CMD_LEN, &(int){ 17 });
write(fd, buf, sizeof(buf));
}

The crash was:

BUG: unable to handle kernel paging request at ffff8cb97db37ffc
IP: ata_bmdma_fill_sg drivers/ata/libata-sff.c:2623 [inline]
IP: ata_bmdma_qc_prep+0xa4/0xc0 drivers/ata/libata-sff.c:2727
PGD fb6c067 P4D fb6c067 PUD 0
Oops: 0002 [#1] SMP
CPU: 1 PID: 150 Comm: syz_ata_bmdma_q Not tainted 4.15.0-next-20180202 #99
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-20171110_100015-anatol 04/01/2014
[...]
Call Trace:
ata_qc_issue+0x100/0x1d0 drivers/ata/libata-core.c:5421
ata_scsi_translate+0xc9/0x1a0 drivers/ata/libata-scsi.c:2024
__ata_scsi_queuecmd drivers/ata/libata-scsi.c:4326 [inline]
ata_scsi_queuecmd+0x8c/0x210 drivers/ata/libata-scsi.c:4375
scsi_dispatch_cmd+0xa2/0xe0 drivers/scsi/scsi_lib.c:1727
scsi_request_fn+0x24c/0x530 drivers/scsi/scsi_lib.c:1865
__blk_run_queue_uncond block/blk-core.c:412 [inline]
__blk_run_queue+0x3a/0x60 block/blk-core.c:432
blk_execute_rq_nowait+0x93/0xc0 block/blk-exec.c:78
sg_common_write.isra.7+0x272/0x5a0 drivers/scsi/sg.c:806
sg_write+0x1ef/0x340 drivers/scsi/sg.c:677
__vfs_write+0x31/0x160 fs/read_write.c:480
vfs_write+0xa7/0x160 fs/read_write.c:544
SYSC_write fs/read_write.c:589 [inline]
SyS_write+0x4d/0xc0 fs/read_write.c:581
do_syscall_64+0x5e/0x110 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x21/0x86

Fixes: 607126c2a21c ("libata-scsi: be tolerant of 12-byte ATAPI commands in 16-byte CDBs")
Reported-by: syzbot+1ff6f9fcc3c35f1c72a95e26528c8e7e3276e4da@syzkaller.appspotmail.com
Cc: <stable@vger.kernel.org> # v2.6.24+
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

libata: Fix compile warning with ATA_DEBUG enabled

This fixs the following comile warnings with ATA_DEBUG enabled,
which detected by Linaro GCC 5.2-2015.11:

drivers/ata/libata-scsi.c: In function 'ata_scsi_dump_cdb':
./include/linux/kern_levels.h:5:18: warning: format '%d' expects
argument of type 'int', but argument 6 has type 'u64 {aka long
long unsigned int}' [-Wformat=]

tj: Patch hand-applied and description trimmed.

Signed-off-by: Dong Bo <dongbo4@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

libata: make static arrays const, reduces object code size

Don't populate const arrayis on the stack, instead make them static.
Makes the object code smaller by over 260 bytes:

Before:
text data bss dec hex filename
64864 5948 4128 74940 124bc drivers/ata/libata-scsi.o

After:
text data bss dec hex filename
64183 6364 4128 74675 123b3 drivers/ata/libata-scsi.o

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

libata: Add new med_power_with_dipm link_power_management_policy setting

As described by Matthew Garret quite a while back:
https://mjg59.dreamwidth.org/34868.html

Intel CPUs starting with the Haswell generation need SATA links to power
down for the "package" part of the CPU to reach low power-states like
PC7 / P8 which bring a significant power-saving with them.

The default max_performance lpm policy does not allow for these high
PC states, both the medium_power and min_power policies do allow this.

The min_power policy saves significantly more power, but there are some
reports of some disks / SSDs not liking min_power leading to system
crashes and in some cases even data corruption has been reported.

Matthew has found a document documenting the default settings of
Intel's IRST Windows driver with which most laptops ship:
https://www-ssl.intel.com/content/dam/doc/reference-guide/sata-devices-implementation-recommendations.pdf

Matthew wrote a patch changing med_power to match those defaults, but
that never got anywhere as some people where reporting issues with the
patch-set that patch was a part of.

This commit is another attempt to make the default IRST driver settings
available under Linux, but instead of changing medium_power and
potentially introducing regressions, this commit adds a new
med_power_with_dipm setting which is identical to the existing
medium_power accept that it enables dipm on top, which makes it match
the Windows IRST driver settings, which should hopefully be safe to
use on most devices.

The med_power_with_dipm setting is close to min_power, except that:
a) It does not use host-initiated slumber mode (ASP not set),
but it does allow device-initiated slumber
b) It does not enable DevSlp mode

On my T440s test laptop I get the following power savings when idle:
medium_power 0.9W
med_power_with_dipm 1.2W
min_power 1.2W

Suggested-by: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

libata: array underflow in ata_find_dev()

My static checker complains that "devno" can be negative, meaning that
we read before the start of the loop. I've looked at the code, and I
think the warning is right. This come from /proc so it's root only or
it would be quite a quite a serious bug. The call tree looks like this:

proc_scsi_write() <- gets id and channel from simple_strtoul()
-> scsi_add_single_device() <- calls shost->transportt->user_scan()
-> ata_scsi_user_scan()
-> ata_find_dev()

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: stable@vger.kernel.org # all versions at this point

sd: add support for TCG OPAL self encrypting disks

Just wire up the generic TCG OPAL infrastructure to the SCSI disk driver
and the Security In/Out commands.

Note that I don't know of any actual SCSI disks that do support TCG OPAL,
but this is required to support ATA disks through libata.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

libata: fix build warning from unused goto label

b1ffbf854e08 ("libata: Support for an ATA PASS-THROUGH(32) command.")
introduced an unused goto label. Remove it.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Tejun Heo <tj@kernel.org>

libata: Support for an ATA PASS-THROUGH(32) command.

SAT-4(SCSI/ATA Translation) supports for an ata pass-thru(32).
This patch will allow to translate an ata pass-thru(32) SCSI cmd
to an ATA cmd.

Signed-off-by: Minwoo Im <dn3108@gmail.com>
Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

libata: make the function name in comment match the actual function

The function name used to be ata_scsiop_mode_select() but renamed to
ata_scsi_mode_select_xlat(). Update the comment accordingly.

tj: Minor commit desc update.

Signed-off-by: Minwoo Im <dn3108@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

libata: Convert bare printks to pr_cont

Linus Torvalds changed the behavior of printks without KERN_<LEVEL>.

Convert the continuation prints to use pr_cont.

At the same time, convert the existing printks with KERN_<LEVEL> to
pr_<level>

Miscellanea:

o Coalesce a multiline format

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

libata: implement SECURITY PROTOCOL IN/OUT

This allows us to use the generic OPAL code with ATA devices.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Tejun Heo <tj@kernel.org>

ata: update references for libata documentation

The libata documentation is now using ReST. Update references
to it to point to the new place.

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Acked-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

libata: fix identation on a kernel-doc markup

Sphinx got confused with the markup identation:
./drivers/ata/libata-scsi.c:3402: ERROR: Unexpected indentation.

No functional changes.

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

ata: update references for libata documentation

The libata documentation is now using ReST. Update references
to it to point to the new place.

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

libata: fix identation on a kernel-doc markup

Sphinx got confused with the markup identation:
./drivers/ata/libata-scsi.c:3402: ERROR: Unexpected indentation.

No functional changes.

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

libata: remove SCT WRITE SAME support

This was already disabled a while ago because it caused I/O errors,
and it's severly getting into the way of the discard / write zeroes
rework.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

libata: reject passthrough WRITE SAME requests

The WRITE SAME to TRIM translation rewrites the DATA OUT buffer. While
the SCSI code accomodates for this by passing a read-writable buffer
userspace applications don't cater for this behavior. In fact it can
be used to rewrite e.g. a readonly file through mmap and should be
considered as a security fix.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: stable@vger.kernel.org
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

scsi: merge __scsi_execute into scsi_execute

All but one caller want the decoded sense header, so offer the existing
__scsi_execute helper as the public scsi_execute API to simply the
callers.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

block: introduce blk_rq_is_passthrough

This can be used to check for fs vs non-fs requests and basically
removes all knowledge of BLOCK_PC specific from the block layer,
as well as preparing for removing the cmd_type field in struct request.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>

block: split scsi_request out of struct request

And require all drivers that want to support BLOCK_PC to allocate it
as the first thing of their private data. To support this the legacy
IDE and BSG code is switched to set cmd_size on their queues to let
the block layer allocate the additional space.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>

Revert "libata: switch to dynamic allocation instead of ata_scsi_rbuf"

This reverts commit a234f7395c9301a5048cb2daa4c86f15c6f02de8.

The commit tried to get rid of the shared global SCSI response buffer.
Unfortunately, it added blocking allocation to atomic path. Revert it
for now.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Christoph Hellwig <hch@lst.de>

libata: switch to dynamic allocation instead of ata_scsi_rbuf

Note of the emulated commands in the pageout/pagein path, so just do
a GFP_NOIO dynamic allocation.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Tejun Heo <tj@kernel.org>

libata: don't call ata_scsi_rbuf_fill for command without a response buffer

No need to copy a zeroed buffer to the caller if the command is defined
to not have a response in the SCSI spec.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Tejun Heo <tj@kernel.org>

libata: call ->scsi_done from ata_scsi_simulate

We always need to call ->scsi_done after we've finished emulating a
command, so do it in a single place at the end of ata_scsi_simulate.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Tejun Heo <tj@kernel.org>

libata: remove the done callback from ata_scsi_args

It's always the scsi_done callback, and we can get at that easily
in the place where ->done is called.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Tejun Heo <tj@kernel.org>

libata: move struct ata_scsi_args to libata-scsi.c

It's only used in libata-scsi.c, so move it closer to the users.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Tejun Heo <tj@kernel.org>

libata: avoid global response buffer in atapi_qc_complete

We only need to look at 4 bytes of the inquiry response for ATAPI
devices. Instead of using the global ata_scsi_rbuf just use a
a stack buffer. Also factor the fixup into it's own little helper
function to make it more readable.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Tejun Heo <tj@kernel.org>

ata: avoid probing NCQ Prio Support if not explicitly requested

Previously, when the ata device was being initialized we were
probing for NCQ prio support by checking the identify information
and also checking the log page that holds information about ncq prio
support.

This caused an error on an Intel HBA so the code is now updated to
only probe for NCQ prio support when the sysfs variable controlling
NCQ prio support is enabled.

tj: Update formatting, switch to spin_[un]lock_irq() and update
locking a bit, use REVALIDATE instead of RESET, and return -EIO
instead of -EINVAL on config failure.

Signed-off-by: Adam Manzanares <adam.manzanares@wdc.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

libata-scsi: disable SCT Write Same for the moment

SCT Write Same support had been introduced with
commit 7b2030942859 ("libata: Add support for SCT Write Same")

Some problems, namely excessive userspace segfaults, had been reported at

http://lkml.kernel.org/r/20160908192736.GA4356@gmail.com

This lead to commit 0ce1b18c42a5 ("libata: Some drives failing on
SCT Write Same") which strived to disable SCT Write Same on !ZAC devices.
Due to the way this was done and to the logic in sd_config_write_same(),
this didn't work for those devices that have
->max_ws_blocks > SD_MAX_WS10_BLOCKS: for these, ->no_write_same and
->max_write_same_sectors would still be non-zero,
but ->ws10 == ->ws16 == 0. This would cause sd_setup_write_same_cmnd() to
demultiplex REQ_OP_WRITE_SAME requests to WRITE_SAME, and these in turn
aren't supported by libata-scsi:

EXT4-fs (dm-1): Delayed block allocation failed for inode 2625094 at
logical offset 2032 with max blocks 2 with error 121
EXT4-fs (dm-1): This should not happen!! Data will be lost

121 == EREMOTEIO is what scsi_io_completion() asserts in case of
invalid opcodes.

Back to the original problem of userspace segfaults: this can be tracked
down to ata_format_sct_write_same() overwriting the input page. Sometimes,
this page is ZERO_PAGE(0) which ceases to be filled with zeros from that
point on. Since ZERO_PAGE(0) is used for userspace .bss mappings, code of
the following is doomed:

static char *a = NULL; /* .bss */
...
if (a)
*a = 'a';

This problem is not solved by disabling SCT Write Same for !ZAC devices
only.

It can certainly be fixed, but the final release is quite close -- so
disable SCT Write Same for all ATA devices rather than introducing some
SCT key buffer allocation schemes at this point.

Fixes: 7b2030942859 ("libata: Add support for SCT Write Same")
Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

libata-scsi: Fixup ata_gen_passthru_sense()

There's a typo in ata_gen_passthru_sense(), where the first byte
would be overwritten incorrectly later on.

Reported-by: Charles Machalow <csm10495@gmail.com>
Signed-off-by: Hannes Reinecke <hare@suse.com>
Fixes: 11093cb1ef56 ("libata-scsi: generate correct ATA pass-through sense")
Cc: stable@vger.kernel.org # v4.7+
Signed-off-by: Tejun Heo <tj@kernel.org>

ata: set ncq_prio_enabled iff device has support

We previously had a check to see if the device has support for
prioritized ncq commands and a check to see if a device flag
is set, through a sysfs variable, in order to send a prioritized
command.

This patch only allows the sysfs variable to be set if the device
supports prioritized commands enabling one check in ata_build_rw_tf
in order to determine whether or not to send a prioritized command.

This patch depends on ata: ATA Command Priority Disabled By Default

tj: Minor subject and formatting updates.

Signed-off-by: Adam Manzanares <adam.manzanares@wdc.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

ata: ATA Command Priority Disabled By Default

Add a sysfs entry to turn on priority information being passed
to a ATA device. By default this feature is turned off.

This patch depends on ata: Enabling ATA Command Priorities

tj: Renamed ncq_prio_on to ncq_prio_enable and removed trivial
ata_ncq_prio_on() and open-coded the test.

Signed-off-by: Adam Manzanares <adam.manzanares@hgst.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

ata: Enabling ATA Command Priorities

This patch checks to see if an ATA device supports NCQ command priorities.
If so and the user has specified an iocontext that indicates
IO_PRIO_CLASS_RT then we build a tf with a high priority command.

This is done to improve the tail latency of commands that are high
priority by passing priority to the device.

tj: Removed trivial ata_ncq_prio_enabled() and open-coded the test.

Signed-off-by: Adam Manzanares <adam.manzanares@hgst.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

libata: Some drives failing on SCT Write Same

Restrict support SCT Write Same to devices which also support ZAC where
support is required.

Reported-by: Mike Krinkin <krinkin.m.u@gmail.com>
Signed-off-by: Shaun Tancheff <shaun.tancheff@seagate.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

libata: SCT Write Same handle ATA_DFLAG_PIO

Use non DMA write log when ATA_DFLAG_PIO is set.

Signed-off-by: Shaun Tancheff <shaun.tancheff@seagate.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Acked-by: Tejun Heo <tj@kernel.org>

libata: SCT Write Same / DSM Trim

Correct handling of devices with sector_size other that 512 bytes.

In the case of a 4Kn device sector_size it is possible to describe a much
larger DSM Trim than the current fixed default of 512 bytes.

This patch assumes the minimum descriptor is sector_size and fills out
the descriptor accordingly.

The ACS-2 specification is quite clear that the DSM command payload is
sized as number of 512 byte transfers so a 4Kn device will operate
correctly without this patch.

Signed-off-by: Shaun Tancheff <shaun.tancheff@seagate.com>
Acked-by: Tejun Heo <tj@kernel.org>

libata: Add support for SCT Write Same

SATA drives may support write same via SCT. This is useful
for setting the drive contents to a specific pattern (0's).

Translate a SCSI WRITE SAME 16 command to be either a DSM TRIM
command or an SCT Write Same command.

Based on the UNMAP flag:
- When set translate to DSM TRIM
- When not set translate to SCT Write Same

Signed-off-by: Shaun Tancheff <shaun.tancheff@seagate.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Acked-by: Tejun Heo <tj@kernel.org>

libata: Safely overwrite attached page in WRITE SAME xlat

Safely overwriting the attached page to ATA format from the SCSI formatted
variant.

Signed-off-by: Shaun Tancheff <shaun.tancheff@seagate.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Acked-by: Tejun Heo <tj@kernel.org>

libata-scsi: fix MODE SELECT translation for Control mode page

scsi_done() was called repeatedly and apparently because of that,
the kernel would call trace when we touch the Control mode page:

Call Trace:
[<ffffffff812ea0d2>] dump_stack+0x63/0x81
[<ffffffff81079cfb>] __warn+0xcb/0xf0
[<ffffffff81079e2d>] warn_slowpath_null+0x1d/0x20
[<ffffffffa00f51b0>] ata_eh_finish+0xe0/0xf0 [libata]
[<ffffffffa00fb830>] sata_pmp_error_handler+0x640/0xa50 [libata]
[<ffffffffa00470ed>] ahci_error_handler+0x1d/0x70 [libahci]
[<ffffffffa00f55f0>] ata_scsi_port_error_handler+0x430/0x770 [libata]
[<ffffffffa00eff8d>] ? ata_scsi_cmd_error_handler+0xdd/0x160 [libata]
[<ffffffffa00f59d7>] ata_scsi_error+0xa7/0xf0 [libata]
[<ffffffffa00913ba>] scsi_error_handler+0xaa/0x560 [scsi_mod]
[<ffffffffa0091310>] ? scsi_eh_get_sense+0x180/0x180 [scsi_mod]
[<ffffffff81098eb8>] kthread+0xd8/0xf0
[<ffffffff815d913f>] ret_from_fork+0x1f/0x40
[<ffffffff81098de0>] ? kthread_worker_fn+0x170/0x170
---[ end trace 8b7501047e928a17 ]---

Removed the unnecessary code and let ata_scsi_translate() do the job.

Also, since ata_mselect_control() has no ATA command to send to the
device, ata_scsi_mode_select_xlat() should return 1 for it, so that
ata_scsi_translate() will finish early to avoid ata_qc_issue().

Signed-off-by: Tom Yan <tom.ty89@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

libata-scsi: use u8 array to store mode page copy

ata_mselect_*() would initialize a char array for storing a copy of
the current mode page. However, char could be signed char. In that
case, bytes larger than 127 would be converted to negative number.

For example, 0xff from def_control_mpage[] would become -1. This
prevented ata_mselect_control() from working at all, since when it
did the read-only bits check, there would always be a mismatch.

Signed-off-by: Tom Yan <tom.ty89@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

libata-scsi: better style in ata_msense_*()

`changeable` is the "version" of mode page requested by the user.
It will be less confusing/misleading if we do not check it
"together" with the setting bits of the drive.

Not to mention that we currently have ata_mselect_*() implemented
in a way that each of them will serve exclusively a particular bit
on each page. The old style will hence make the condition look even
more unnecessarily arcane if the ata_msense_*() is reflecting more
than one bit.

Signed-off-by: Tom Yan <tom.ty89@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

libata-scsi: minor cleanup for ata_scsi_zbc_out_xlat

The reset_all variable name is misleading as this bit is also applicable to
open, close, and finish actions. So rename that variable to "all" and remove
the unnecessary mask operation that's already done earlier.

Signed-off-by: Damien Le Moal <damien.lemoal@hgst.com>
[hch: split from the previous patch]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Tejun Heo <tj@kernel.org>

libata-scsi: Fix ZBC management out command translation

The subcommand for NCQ NON-DATA must be specified in the feature
(low byte), not the high-order count byte. Also make sure to properly
cast the all bit to a u16 before shiting it by 8 to avoid undefined
behavior.

Signed-off-by: Damien Le Moal <damien.lemoal@hgst.com>
[hch: split the original patch into two, updated changelog]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Tejun Heo <tj@kernel.org>

libata-scsi: Fix translation of REPORT ZONES command

Include reporting options when translating REPORT ZONES commmand to
ATA NCQ, and make sure we only look at the actually specified bits
in the CDB for the options.

Signed-off-by: Damien Le Moal <damien.lemoal@hgst.com>
[hch: update patch description]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Tejun Heo <tj@kernel.org>

ata: Handle ATA NCQ NO-DATA commands correctly

Add a new taskfile protocol ATA_PROT_NCQ_NODATA to handle
ATA NCQ NO-DATA commands correctly.
And fixup ata_scsi_zbc_out_xlat() to use it.

Signed-off-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Tejun Heo <tj@kernel.org>

libata: use ata_is_ncq() accessors

Use accessor functions instead of the raw value.

Signed-off-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Tejun Heo <tj@kernel.org>

libata-scsi: avoid repeated calculation of number of TRIM ranges

Currently libata statically allows only 1-block (512-byte) payload
for each TRIM command. Each payload can carry 64 TRIM ranges since
each range requires 8 bytes.

It is silly to keep doing the calculation (512 / 8) in different
places. Hence, define the new ATA_MAX_TRIM_RNUM for the result.

Signed-off-by: Tom Yan <tom.ty89@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

libata-scsi: reject WRITE SAME (16) with n_block that exceeds limit

Currently if a WRITE SAME (16) command is issued to the SATL with
"number of blocks" that is larger than the "Maximum write same length"
(which is the maximum number of blocks per TRIM command allowed in
libata, currently 65535 * 512 / 8 blocks), the SATL will accept the
command and translate it to a TRIM command with the upper limit.

However, according to SBC (as of sbc4r11.pdf), the "device server"
should terminate the command with "Invalid field in CDB" in that case.

Signed-off-by: Tom Yan <tom.ty89@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

libata-scsi: rename ata_msense_ctl_mode() to ata_msense_control()

To make it consistent with the recently added ata_mselect_control().
We probably shouldn't have the word "mode" in its name anyway, since
that's not the case for other ata_msense_*() / ata_mselect_*() either.

Signed-off-by: Tom Yan <tom.ty89@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

libata-scsi: fix D_SENSE bit relection in control mode page

The bit should always be set to 1 when the requested version of
page is "changeable" because we've made it so in ata_mselect_control().
Also, it should always be set to 1 if ATA_DFLAG_D_SENSE is set (when
the requested version of page is "current" or "default").

Signed-off-by: Tom Yan <tom.ty89@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

libata-scsi: correct SPC version descriptor

The comment suggests we should be having an SPC-3 version descriptor
but the 0260h is the code for "SPC-2 (no version claimed)". Correct
it to 0300h so that it has the "SPC-3 (no version claimed)" descriptor.

Note that we are claiming SPC-3 version compatibility in the VERSION
field of the standard INQUIRY data. Therefore, I assume the typo was
on the code but not on the comment.

Signed-off-by: Tom Yan <tom.ty89@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

libata-scsi: set CmdQue bit in standard INQUIRY data to 1

Avoid performance bottleneck when being SCSI pass-through'd to
virtual machines with other OSes (e.g. Windows) via virtio-scsi
and scsi-block in qemu.

Ref.: https://github.com/YanVugenfirer/kvm-guest-drivers-windows/issues/63

Signed-off-by: Tom Yan <tom.ty89@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

libata-scsi: set correct VERSION field for ZAC devices

Commit 856c46639309 ("libata: support device-managed ZAC devices")
had the line that "bumps" the VERSION field in standard INQUIRY data
removed. Add it back and claim SPC-5 version compatibility, which
matches with the current version descriptor "SPC-5 (no version claimed)"
that is used for ZAC devices.

Signed-off-by: Tom Yan <tom.ty89@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

libata-scsi: correct cbd to CDB in comment

It's Command Descriptor Block. Also capitalized it.

Signed-off-by: Tom Yan <tom.ty89@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

libata-scsi: do not respond with "invalid field" for FORMAT UNIT

It does not make sense and is confusing to respond with "Invalid
field in CDB" while we have no support at all implemented for
FORMAT UNIT. It is decent to let it go to the default, which
will respond with "Invalid command operation code" instead.

Signed-off-by: Tom Yan <tom.ty89@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

block, drivers, cgroup: use op_is_write helper instead of checking for REQ_WRITE

We currently set REQ_WRITE/WRITE for all non READ IOs
like discard, flush, writesame, etc. In the next patches where we
no longer set up the op as a bitmap, we will not be able to
detect a operation direction like writesame by testing if REQ_WRITE is
set.

This patch converts the drivers and cgroup to use the
op_is_write helper. This should just cover the simple
cases. I did dm, md and bcache in their own patches
because they were more involved.

Signed-off-by: Mike Christie <mchristi@redhat.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

libata: support host-aware and host-managed ZAC devices

Byte 69 bits 0:1 in the IDENTIFY DEVICE data indicate a
host-aware ZAC device.
Host-managed ZAC devices have their own individual signature,
and to not set the bits in the IDENTIFY DEVICE data.
And whenever we detect a ZAC-compatible device we should
be displaying the zoned block characteristics VPD page.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Tejun Heo <tj@kernel.org>

libata: support device-managed ZAC devices

Device-managed ZAC devices just set the zoned capabilities field
in INQUIRY byte 69 (cf ACS-4). This corresponds to the 'zoned'
field in the block device characteristics VPD page.
As this is only defined in SPC-5/SBC-4 we also need to update
the supported SCSI version descriptor.

Reviewed-by: Shaun Tancheff <shaun.tancheff@seagate.com>
Tested-by: Shaun Tancheff <shaun.tancheff@seagate.com>
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Tejun Heo <tj@kernel.org>

libata: NCQ encapsulation for ZAC MANAGEMENT OUT

Add NCQ encapsulation for ZAC MANAGEMENT OUT and evaluate
NCQ Non-Data log pages to figure out if NCQ encapsulation
is supported.

Signed-off-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

libata: Implement ZBC OUT translation

ZAC drives implement a 'ZAC Management Out' command template,
which maps onto the ZBC OUT command.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Tejun Heo <tj@kernel.org>

libata: implement ZBC IN translation

ZAC drives implement a 'ZAC Management In' command template,
which maps onto the ZBC IN command.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Tejun Heo <tj@kernel.org>

libata-scsi: Generate sense code for disabled devices

If a device is disabled after error recovery it doesn't make
any sense to generate an ATA sense, but we should rather
return a generic sense code indicating the device is gone.

Signed-off-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

libata-scsi: use %*ph to dump small buffers

Replace custom approach by %*ph specifier to dump small buffers in hex format.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

treewide: Fix typos in libata.xml

This patch fix spelling typos found in Documentation/Docbook/libata.xml.
It is because the file was generated from comments in source,
I had to fix comments in libata-core.c

Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Tejun Heo <tj@kernel.org>

libata-scsi: Set information sense field for invalid parameter

Whenever the sense key is set to 'invalid parameter' we should
be filling out the sense-key specific information field in the
sense buffer.

tj: Added description of @fp for ata_mselect_*().

Signed-off-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

libata-scsi: set bit pointer for sense code information

When generating a sense code of 'Invalid field in CDB' we
should be setting the bit pointer where appropriate.

Signed-off-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

libata-scsi: Set field pointer in sense code

If the sense code is 'Invalid field in CDB' we should be
setting the field pointer to the offending byte.

Signed-off-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

libata: Implement control mode page to select sense format

Implement MODE SELECT for the control mode page to allow the OS
to switch to descriptor sense.

tj: Dropped s/sb/cmd->sense_buffer/ in ata_gen_ata_sense(). Added
@dev description to ata_msense_ctl_mode().

Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Tejun Heo <tj@kernel.org>

libata-scsi: generate correct ATA pass-through sense

Generate ATA pass-through sense for both fixed and descriptor
format sense.

Signed-off-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

libata-scsi: use ata_scsi_set_sense()

Use ata_scsi_set_sense() throughout to ensure the sense code
format is consistent.

Signed-off-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

libata-eh: Set 'information' field for autosense

If NCQ autosense or the sense data reporting feature is enabled
the LBA of the offending command should be stored in the sense
data 'information' field.

tj: s/(u64)-1/U64_MAX/

Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Tejun Heo <tj@kernel.org>

libata-scsi: use scsi_set_sense_information()

Use scsi_set_sense_information() instead of hand-crafted function.

Signed-off-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

libata: sanitize ata_tf_read_block()

Return U64_MAX if ata_tf_read_block() could not decode the LBA
address, and do not set the information sense descriptor in
ata_gen_ata_sense() in these cases.

tj: s/(u64)-1/U64_MAX/

Signed-off-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

libata-scsi: sanitize ata_gen_ata_sense()

ata_to_sense_error() is called conditionally, so we should be
generating a default sense if the condition is not met.

Signed-off-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

libata: Implement NCQ autosense

Some newer devices support NCQ autosense (cf ACS-4), so we should
be using it to retrieve the sense code and speed up recovery.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Tejun Heo <tj@kernel.org>

libata: fix unbalanced spin_lock_irqsave/spin_unlock_irq() in ata_scsi_park_show()

ata_scsi_park_show() was pairing spin_lock_irqsave() with
spin_unlock_irq(). As the function is always called with irq enabled,
it didn't actually break anything. Use spin_lock_irq() instead.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Elias Oltmanns <eo@nebensachen.de>

libata: fix HDIO_GET_32BIT ioctl

As reported by Soohoon Lee, the HDIO_GET_32BIT ioctl does not
work correctly in compat mode with libata.

I have investigated the issue further and found multiple problems
that all appeared with the same commit that originally introduced
HDIO_GET_32BIT handling in libata back in linux-2.6.8 and presumably
also linux-2.4, as the code uses "copy_to_user(arg, &val, 1)" to copy
a 'long' variable containing either 0 or 1 to user space.

The problems with this are:

* On big-endian machines, this will always write a zero because it
stores the wrong byte into user space.

* In compat mode, the upper three bytes of the variable are updated
by the compat_hdio_ioctl() function, but they now contain
uninitialized stack data.

* The hdparm tool calling this ioctl uses a 'static long' variable
to store the result. This means at least the upper bytes are
initialized to zero, but calling another ioctl like HDIO_GET_MULTCOUNT
would fill them with data that remains stale when the low byte
is overwritten. Fortunately libata doesn't implement any of the
affected ioctl commands, so this would only happen when we query
both an IDE and an ATA device in the same command such as
"hdparm -N -c /dev/hda /dev/sda"

* The libata code for unknown reasons started using ATA_IOC_GET_IO32
and ATA_IOC_SET_IO32 as aliases for HDIO_GET_32BIT and HDIO_SET_32BIT,
while the ioctl commands that were added later use the normal
HDIO_* names. This is harmless but rather confusing.

This addresses all four issues by changing the code to use put_user()
on an 'unsigned long' variable in HDIO_GET_32BIT, like the IDE subsystem
does, and by clarifying the names of the ioctl commands.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reported-by: Soohoon Lee <Soohoon.Lee@f5.com>
Tested-by: Soohoon Lee <Soohoon.Lee@f5.com>
Cc: stable@vger.kernel.org
Signed-off-by: Tejun Heo <tj@kernel.org>

scsi: use host wide tags by default

This patch changes the !blk-mq path to the same defaults as the blk-mq
I/O path by always enabling block tagging, and always using host wide
tags. We've had blk-mq available for a few releases so bugs with
this mode should have been ironed out, and this ensures we get better
coverage of over tagging setup over different configs.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: James Bottomley <JBottomley@Odin.com>

libata: enable LBA flag in taskfile for ata_scsi_pass_thru()

Enable LBA in taskfile flags for ata_scsi_pass_thru()

Signed-off-by: Vinayak Kale <vinayak.kale@seagate.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

libata: add support for NCQ commands for SG interface

This patch is needed to make NCQ commands with FPDMA protocol value
(eg READ/WRITE FPDMA) work over SCSI Generic (SG) interface.

Signed-off-by: Vinayak Kale <vinayak.kale@seagate.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

libata: only call ->done once all per-tag ressources are released

When calling ->done before releasing resources we could run into a
race where the SCSI midlayer sends another command and races with
the resources beeing manipulated. For libata this can't currently
happen as synchronization happens at a higher level, but I'd still
like to fix it to future proof libata and to avoid copy & paste
into SCSI drivers where this pattern has led to reproducible crashes.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Tejun Heo <tj@kernel.org>

libata: cleanup ata_scsi_qc_complete

Remove an incorrect comment and untangle an if statement in
ata_scsi_qc_complete.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Tejun Heo <tj@kernel.org>

ata: ahci: find eSATA ports and flag them as removable

If the AHCI ports' HPCP or ESP bits are set, the port
should be considered external (e.g. eSATA) and is marked
as removable. Userspace tools like udisks then treat it
like an usb drive.

With this patch applied, when I plug a drive into the esata port,
KDE pops up a window asking what to do with the drives(s), just
like it does for any random USB stick.

Removability is indicated to the upper layers by way of the
SCSI RMB bit, as I haven't found another way to signal
userspace to treat a sata disk like any usb stick.

Signed-off-by: Manuel Lauss <manuel.lauss@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

Revert "libata: Implement NCQ autosense"

This reverts commit 42b966fbf35da9c87f08d98f9b8978edf9e717cf.

As implemented, ACS-4 sense reporting for ATA devices bypasses error
diagnosis and handling in libata degrading EH behavior significantly.
Revert the related changes for now.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Hannes Reinecke <hare@suse.de>
Cc: stable@vger.kernel.org #v4.1+

Revert "libata-eh: Set 'information' field for autosense"

This reverts commit a1524f226a02aa6edebd90ae0752e97cfd78b159.

As implemented, ACS-4 sense reporting for ATA devices bypasses error
diagnosis and handling in libata degrading EH behavior significantly.
Revert the related changes for now.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Hannes Reinecke <hare@suse.de>
Cc: stable@vger.kernel.org #v4.1+

scsi: Protect against buffer possible overflow in scsi_set_sense_information

Make sure that the input sense buffer has sufficient length
to fit the information descriptor (12 additional bytes).
Modify scsi_set_sense_information to receive the sense buffer
length and adjust its callers scsi target and libata.

(Fix patch fuzz in scsi_set_sense_information - nab)

Reported-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Tejun Heo <tj@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

libata: add ATA_HORKAGE_NOTRIM

Some devices lose data on TRIM whether queued or not. This patch adds
a horkage to disable TRIM.

tj: Collapsed unnecessary if() nesting.

Signed-off-by: Arne Fitzenreiter <arne_f@ipfire.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: stable@vger.kernel.org

libata-eh: Set 'information' field for autosense

If NCQ autosense or the sense data reporting feature is enabled
the LBA of the offending command should be stored in the sense
data 'information' field.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Tejun Heo <tj@kernel.org>

libata: Implement NCQ autosense

Some newer devices support NCQ autosense (cf ACS-4), so we should
be using it to retrieve the sense code and speed up recovery.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Tejun Heo <tj@kernel.org>

libata: use status bit definitions in ata_dump_status()

Use the bit definitions for better readability.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Tejun Heo <tj@kernel.org>

ide,ata: Rename ATA_IDX to ATA_SENSE

ATA-8 defines bit 1 as 'ATA_SENSE', not 'ATA_IDX'.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Tejun Heo <tj@kernel.org>

libata: whitespace fixes in ata_to_sense_error()

Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Tejun Heo <tj@kernel.org>

libata: remove ATA_FLAG_LOWTAG

sata_sil24 for some reason pukes when tags are allocated round-robin
which helps tag ordered controllers. To work around the issue,
72dd299d5039 ("libata: allow sata_sil24 to opt-out of tag ordered
submission") introduced ATA_FLAG_LOWTAG which tells libata tag
allocation to do lowest-first.

However, with the recent switch to blk-mq tag allocation, the liata
tag allocation code path is no longer used and the workaround is now
implemented in the block layer and selected by setting
scsi_host_template->tag_alloc_policy to BLK_TAG_ALLOC_FIFO. See
9269e23496dd ("libata: make sata_sil24 use fifo tag allocator").

This leaves ATA_FLAG_LOWTAG withoout any actual user. Remove it.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Shaohua Li <shli@fb.com>
Cc: Dan Williams <dan.j.williams@intel.com>

libata: move sas ata tag allocation to libata-scsi.c

Basically move the sas ata tag allocation to libata-scsi.c to make it clear
these staffs are just for sas.

Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

libata: use blk taging

libata uses its own tag management which is duplication and the
implementation is poor. And if we switch to blk-mq, tag is build-in.
It's time to switch to generic taging.

The SAS driver has its own tag management, and looks we can't directly
map the host controler tag to SATA tag. So I just bypassed the SAS case.

I changed the code/variable name for the tag management of libata to
make it self contained. Only sas will use it. Later if libsas implements
its tag management, the tag management code in libata can be deleted
easily.

Cc: Jens Axboe <axboe@fb.com>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Shaohua Li <shli@fb.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@fb.com>

libata: Whitelist SSDs that are known to properly return zeroes after TRIM

As defined, the DRAT (Deterministic Read After Trim) and RZAT (Return
Zero After Trim) flags in the ATA Command Set are unreliable in the
sense that they only define what happens if the device successfully
executed the DSM TRIM command. TRIM is only advisory, however, and the
device is free to silently ignore all or parts of the request.

In practice this renders the DRAT and RZAT flags completely useless and
because the results are unpredictable we decided to disable discard in
MD for 3.18 to avoid the risk of data corruption.

Hardware vendors in the real world obviously need better guarantees than
what the standards bodies provide. Unfortuntely those guarantees are
encoded in product requirements documents rather than somewhere we can
key off of them programatically. So we are compelled to disabling
discard_zeroes_data for all devices unless we explicitly have data to
support whitelisting them.

This patch whitelists SSDs from a few of the main vendors. None of the
whitelists are based on written guarantees. They are purely based on
empirical evidence collected from internal and external users that have
tested or qualified these drives in RAID deployments.

The whitelist is only meant as a starting point and is by no means
comprehensive:

- All intel SSD models except for 510
- Micron M5?0/M600
- Samsung SSDs
- Seagate SSDs

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Tejun Heo <tj@kernel.org>

libata: s/ata_id_removeable()/ata_id_removable()/

Changes the spelling typos of removeable to removable where
ata_id_removeable is defined in ata.h and called in libata-scsi.c
respectively.

Signed-off-by: Nicholas Krause <xerofoify@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

libata: Remove FIXME comment in atapi_request_sense()

Remove the FIXME comment in atapi_request_sense() asking whether
memset of sense buffer is necessary. The buffer may be partially or
fully filled by the device. We want it to be cleared.

tj: Updated description.

Signed-off-by: Nicholas Krause <xerofoify@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

scsi: rename SERVICE_ACTION_IN to SERVICE_ACTION_IN_16

SPC-3 defines SERVICE ACTION IN(12) and SERVICE ACTION IN(16).
So rename SERVICE_ACTION_IN to SERVICE_ACTION_IN_16 to be
consistent with SPC and to allow for better distinction.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Tested-by: Robert Elliott <elliott@hp.com>
Reviewed-by: Robert Elliott <elliott@hp.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

scsi: drop reason argument from ->change_queue_depth

Drop the now unused reason argument from the ->change_queue_depth method.
Also add a return value to scsi_adjust_queue_depth, and rename it to
scsi_change_queue_depth now that it can be used as the default
->change_queue_depth implementation.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Hannes Reinecke <hare@suse.de>

scsi: don't set tagging state from scsi_adjust_queue_depth

Remove the tagged argument from scsi_adjust_queue_depth, and just let it
handle the queue depth. For most drivers those two are fairly separate,
given that most modern drivers don't care about the SCSI "tagged" status
of a command at all, and many old drivers allow queuing of multiple
untagged commands in the driver.

Instead we start out with the ->simple_tags flag set before calling
->slave_configure, which is how all drivers actually looking at
->simple_tags except for one worke anyway. The one other case looks
broken, but I've kept the behavior as-is for now.

Except for that we only change ->simple_tags from the ->change_queue_type,
and when rejecting a tag message in a single driver, so keeping this
churn out of scsi_adjust_queue_depth is a clear win.

Now that the usage of scsi_adjust_queue_depth is more obvious we can
also remove all the trivial instances in ->slave_alloc or ->slave_configure
that just set it to the cmd_per_lun default.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>

libata-scsi: Update SATL for ZAC drives

ZAC (zoned-access command) drives translate into ZBC (Zoned block
command) device type for SCSI. So implement the correct mappings
into libata-scsi and update the SCSI command set versions.

Acked-by: Christoph Hellwig <hch@lst.de>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Tejun Heo <tj@kernel.org>

libata: Implement ATA_DEV_ZAC

Add new ATA device type for ZAC devices.

Acked-by: Christoph Hellwig <hch@lst.de>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Tejun Heo <tj@kernel.org>

scsi: use 64-bit LUNs

The SCSI standard defines 64-bit values for LUNs, and large arrays
employing large or hierarchical LUN numbers become more and more
common.

So update the linux SCSI stack to use 64-bit LUN numbers.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Christoph Hellwig <hch@infradead.org>
Reviewed-by: Ewan Milne <emilne@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

ata: SATL compliance for Inquiry Product Revision

The SCSI-to-ATA Translation standard says to use data words 25 and 26
unless they are spaces. For devices that use these words in the firmware
field, they are generally more useful anyway.

Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

libata: disable LPM for some WD SATA-I devices

For some reason, some early WD drives spin up and down drives
erratically when the link is put into slumber mode which can reduce
the life expectancy of the device significantly. Unfortunately, we
don't have full list of devices and given the nature of the issue it'd
be better to err on the side of false positives than the other way
around. Let's disable LPM on all WD devices which match one of the
known problematic model prefixes and are SATA-I.

As horkage list doesn't support matching SATA capabilities, this is
implemented as two horkages - WD_BROKEN_LPM and NOLPM. The former is
set for the known prefixes and sets the latter if the matched device
is SATA-I.

Note that this isn't optimal as this disables all LPM operations and
partial link power state reportedly works fine on these; however, the
way LPM is implemented in libata makes it difficult to precisely map
libata LPM setting to specific link power state. Well, these devices
are already fairly outdated. Let's just disable whole LPM for now.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-and-tested-by: Nikos Barkas <levelwol@gmail.com>
Reported-and-tested-by: Ioannis Barkas <risc4all@yahoo.com>
References: https://bugzilla.kernel.org/show_bug.cgi?id=57211
Cc: stable@vger.kernel.org

libata, freezer: avoid block device removal while system is frozen

Freezable kthreads and workqueues are fundamentally problematic in
that they effectively introduce a big kernel lock widely used in the
kernel and have already been the culprit of several deadlock
scenarios. This is the latest occurrence.

During resume, libata rescans all the ports and revalidates all
pre-existing devices. If it determines that a device has gone
missing, the device is removed from the system which involves
invalidating block device and flushing bdi while holding driver core
layer locks. Unfortunately, this can race with the rest of device
resume. Because freezable kthreads and workqueues are thawed after
device resume is complete and block device removal depends on
freezable workqueues and kthreads (e.g. bdi_wq, jbd2) to make
progress, this can lead to deadlock - block device removal can't
proceed because kthreads are frozen and kthreads can't be thawed
because device resume is blocked behind block device removal.

839a8e8660b6 ("writeback: replace custom worker pool implementation
with unbound workqueue") made this particular deadlock scenario more
visible but the underlying problem has always been there - the
original forker task and jbd2 are freezable too. In fact, this is
highly likely just one of many possible deadlock scenarios given that
freezer behaves as a big kernel lock and we don't have any debug
mechanism around it.

I believe the right thing to do is getting rid of freezable kthreads
and workqueues. This is something fundamentally broken. For now,
implement a funny workaround in libata - just avoid doing block device
hot[un]plug while the system is frozen. Kernel engineering at its
finest. :(

v2: Add EXPORT_SYMBOL_GPL(pm_freezing) for cases where libata is built
as a module.

v3: Comment updated and polling interval changed to 10ms as suggested
by Rafael.

v4: Add #ifdef CONFIG_FREEZER around the hack as pm_freezing is not
defined when FREEZER is not configured thus breaking build.
Reported by kbuild test robot.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Tomaž Šolc <tomaz.solc@tablix.org>
Reviewed-by: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=62801
Link: http://lkml.kernel.org/r/20131213174932.GA27070@htj.dyndns.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Len Brown <len.brown@intel.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: stable@vger.kernel.org
Cc: kbuild test robot <fengguang.wu@intel.com>

[SCSI] Disable WRITE SAME for RAID and virtual host adapter drivers

Some host adapters do not pass commands through to the target disk
directly. Instead they provide an emulated target which may or may not
accurately report its capabilities. In some cases the physical device
characteristics are reported even when the host adapter is processing
commands on the device's behalf. This can lead to adapter firmware hangs
or excessive I/O errors.

This patch disables WRITE SAME for devices connected to host adapters
that provide an emulated target. Driver writers can disable WRITE SAME
by setting the no_write_same flag in the host adapter template.

[jejb: fix up rejections due to eh_deadline patch]
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Cc: stable@kernel.org
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

ATA / ACPI: remove power dependent device handling

Previously, we wanted SCSI devices corrsponding to ATA devices to
be runtime resumed when the power resource for those ATA device was
turned on by some other device, so we added the SCSI device to the
dependent device list of the ATA device's ACPI node. However, this
code has no effect after commit 41863fc (ACPI / power: Drop automaitc
resume of power resource dependent devices) and the mechanism it was
supposed to implement is regarded as a bad idea now, so drop it.

[rjw: Changelog]
Signed-off-by: Aaron Lu <aaron.lu@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

libata: Add support for queued DSM TRIM

Some new SSDs support the queued version of the DSM TRIM command.
Let the driver use the new command if supported.

Signed-off-by: Marc Carino <marc.ceeeee@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

ata: acpi: rework the ata acpi bind support

Binding ACPI handle to SCSI device has several drawbacks, namely:
1 During ATA device initialization time, ACPI handle will be needed
while SCSI devices are not created yet. So each time ACPI handle is
needed, instead of retrieving the handle by ACPI_HANDLE macro,
a namespace scan is performed to find the handle for the corresponding
ATA device. This is inefficient, and also expose a restriction on
calling path not holding any lock.
2 The binding to SCSI device tree makes code complex, while at the same
time doesn't bring us any benefit. All ACPI handlings are still done
in ATA module, not in SCSI.

Rework the ATA ACPI binding code to bind ACPI handle to ATA transport
devices(ATA port and ATA device). The binding needs to be done only once,
since the ATA transport devices do not go away with hotplug. And due to
this, the flush_work call in hotplug handler for ATA bay is no longer
needed.

Tested on an Intel test platform for binding and runtime power off for
ODD(ZPODD) and hard disk; on an ASUS S400C for binding and normal boot
and S3, where its SATA port node has _SDD and _GTF control methods when
configured as an AHCI controller and its PATA device node has _GTF
control method when configured as an IDE controller. SATA PMP binding
and ATA hotplug is not tested.

Signed-off-by: Aaron Lu <aaron.lu@intel.com>
Tested-by: Dirk Griesbach <spamthis@freenet.de>
Signed-off-by: Tejun Heo <tj@kernel.org>

libata: replace strict_strtol() with kstrtol()

The usage of strict_strtol() is not preferred, because
strict_strtol() is obsolete. Thus, kstrtol() should be
used.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

libata: cleanup SAT error translation

- Remove duplicate Medium Error Entry.

- Fix translations to match SAT2 translation table.

- Remove warning messages when translation is not found when decoding
error or status register.

- Goes through status register decoding when only ABRT bit is set in
error register.

Tested: When a disk fails, it sets

Status = 0x71 [DRDY DF ERR] , Error = 0x4 [ABRT]

This patch will make the sense key HARDWARE_ERROR instead.

When there is a simple command syntax error:

Status = 0x51 [DRDY ERR] , Error = 0x4 [ABRT]

The sense key remains ABORTED_COMMAND.

tj: Some updates to the description and comments.

Signed-off-by: Gwendal Grignou <gwendal@google.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

libata: update "Maintained by:" tags

Jeff moved on to a greener pasture.

s/Maintained by: Jeff Garzik/Maintained by: Tejun Heo/g

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jeff Garzik <jgarzik@pobox.com>

[libata] SCSI: really use SATL version in VPD

As per c78968bb by Jeff Garzik ([libata] SCSI: simulator version, not device
version, belongs in VPD) We need to provide the SATL driver version and not the
disk firmware version but the code overwrites the driver version with the disk
version.

Signed-off-by: Baruch Even <baruch@ev-en.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

libata-acpi: remove redundent code for power resource handling

With commit:
bc9b6407bd6df3ab7189e5622816bbc11ae9d2d8
ACPI / PM: Rework the handling of devices depending on power resources

The ACPI core now takes care of the power resources an acpi device
depends on in that when the power resources are turned on, any devices
that are bound to or in the dependent list of this acpi device will be
runtime resumed. So there is no need for ata acpi code to duplicate this
effort, and thus, the ata_acpi_(un)register_power_resource functions are
no longer needed.

The above commit thinks the scsi device is not bound to the acpi device,
so needs to be added to the dependent list. But actually, it is. So
there is no need to add it to the dependent list, or it will be runtime
resumed twice(though this wouldn't cause any problem).

This patch fixes it, and as a result, the
ata_acpi_(un)register_power_resource and ata_acpi_(un)bind functions
are removed.

Signed-off-by: Aaron Lu <aaron.lu@intel.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

[libata] Fix HDIO_DRIVE_* ioctl() Linux 3.9 regression

On Mon, Mar 25, 2013 at 06:26:50PM +0100, Ronald wrote:
> In reply to [1]: I have the same issue. Git bisect took 50+ rebuilds xD
>
> Smartd does not work anymore since 84a9a8cd9 ([libata] Set proper SK
> when CK_COND is set.).

> [1] http://www.spinics.net/lists/linux-ide/msg45268.html

It seems that the SAM_STAT_CHECK_CONDITION is not cleared
causing -EIO, because that patch modified sensebuf and
the check for clearing SAM_STAT_CHECK_CONDITION is no longer valid.

Fix that.

Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

[libata] Set proper SK when CK_COND is set.

When the user application sends a ATA_12 or ATA_16 PASSTHROUGH
scsi command, put the task file register in the sense data with the
proper Sense Key. Instead of NO SENSE, set RECOVERED, as
specified in [SAT2]12.2.5 Table 92.

Tested:
Using udev ata_id to generate a passthrough command, IDENTIFY:
before:
sd 0:0:0:0: [sda] CDB: ATA command pass through(12)/Blank: \
a1 08 2e 00 01 00 00 00 00 ec 00 00
sd 0:0:0:0: [sda] Sense Key : No Sense [current] [descriptor]
Descriptor sense data with sense descriptors (in hex):
72 00 00 00 00 00 00 0e 09 0c 00 00 00 00 00 3f
00 18 00 a6 e0 50

after
sd 0:0:0:0: [sda] CDB: ATA command pass through(12)/Blank: \
a1 08 2e 00 01 00 00 00 00 ec 00 00
sd 0:0:0:0: [sda] Sense Key : Recovered Error [current] [descriptor]
Descriptor sense data with sense descriptors (in hex):
72 01 00 1d 00 00 00 0e 09 0c 00 00 00 01 00 00
00 00 00 00 00 50

Signed-off-by: Gwendal Grignou <gwendal@google.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

libata: identify and init ZPODD devices

The ODD can be enabled for ZPODD if the following three conditions are
satisfied:
1 The ODD supports device attention;
2 The platform can runtime power off the ODD through ACPI;
3 The ODD is either slot type or drawer type.
For such ODDs, zpodd_init is called and a new structure is allocated for
it to store ZPODD related stuffs.

And the zpodd_dev_enabled function is used to test if ZPODD is currently
enabled for this ODD.

A new config CONFIG_SATA_ZPODD is added to selectively build ZPODD code.

Signed-off-by: Aaron Lu <aaron.lu@intel.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

[libata] fix Null pointer dereference on disk error

Following oops were observed when disk error happened:

[ 4272.896937] sd 0:0:0:0: [sda] Unhandled error code
[ 4272.896939] sd 0:0:0:0: [sda] Result: hostbyte=DID_BAD_TARGET driverbyte=DRIVER_OK
[ 4272.896942] sd 0:0:0:0: [sda] CDB: Read(10): 28 00 00 5a de a7 00 00 08 00
[ 4272.896951] end_request: I/O error, dev sda, sector 5955239
[ 4291.574947] BUG: unable to handle kernel NULL pointer dereference at (null)
[ 4291.658305] IP: [] ahci_activity_show+0x1/0x40
[ 4291.730090] PGD 76dbbc067 PUD 6c4fba067 PMD 0
[ 4291.783408] Oops: 0000 [#1] SMP
[ 4291.822100] last sysfs file: /sys/devices/pci0000:00/0000:00:1f.2/host0/target0:0:0/0:0:0:0/sw_activity
[ 4291.934235] CPU 9
[ 4291.958301] Pid: 27942, comm: hwinfo ......

ata_scsi_find_dev could return NULL, so ata_scsi_activity_{show,store} should check if atadev is NULL.

Signed-off-by: Xiaotian Feng <dannyfeng@tencent.com>
Cc: James Bottomley <JBottomley@Parallels.com>
Cc: stable@kernel.org
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

[SCSI] sd: Implement support for WRITE SAME

Implement support for WRITE SAME(10) and WRITE SAME(16) in the SCSI disk
driver.

- We set the default maximum to 0xFFFF because there are several
devices out there that only support two-byte block counts even with
WRITE SAME(16). We only enable transfers bigger than 0xFFFF if the
device explicitly reports MAXIMUM WRITE SAME LENGTH in the BLOCK
LIMITS VPD.

- max_write_same_blocks can be overriden per-device basis in sysfs.

- The UNMAP discovery heuristics remain unchanged but the discard
limits are tweaked to match the "real" WRITE SAME commands.

- In the error handling logic we now distinguish between WRITE SAME
with and without UNMAP set.

The discovery process heuristics are:

- If the device reports a SCSI level of SPC-3 or greater we'll issue
READ SUPPORTED OPERATION CODES to find out whether WRITE SAME(16) is
supported. If that's the case we will use it.

- If the device supports the block limits VPD and reports a MAXIMUM
WRITE SAME LENGTH bigger than 0xFFFF we will use WRITE SAME(16).

- Otherwise we will use WRITE SAME(10) unless the target LBA is beyond
0xFFFFFFFF or the block count exceeds 0xFFFF.

- no_write_same is set for ATA, FireWire and USB.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Mike Snitzer <snitzer@redhat.com>
Reviewed-by: Jeff Garzik <jgarzik@redhat.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] Add a report opcode helper

The REPORT SUPPORTED OPERATION CODES command can be used to query
whether a given opcode is supported by a device. Add a helper function
that allows us to look up commands.

We only issue RSOC if the device reports compliance with SPC-3 or
later. But to err on the side of caution we disable the command for ATA,
FireWire and USB.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[libata] scsi: implement MODE SELECT command

The cache_type file in sysfs lets users configure the disk cache in
write-through or write-back modes. However, ata disks do not support
writing to the file because they do not implement the MODE SELECT
command.

This patch adds a translation from MODE SELECT (for the caching page
only) to the ATA SET FEATURES command. The set of changeable parameters
answered by MODE SENSE is also adjusted accordingly.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

[libata] scsi: support MODE SENSE request for changeable and default parameters

Since the next patch will introduce support for MODE SELECT, it
makes sense to start advertising which bits are actually changeable.
For now, the answer is none.

Default parameters can also be reported, they are simply the same
as the current parameters.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

[libata] scsi: Remove unlikely() from FUA check

Some other unlikely() should probably be removed as well. A fresh look
reveals an over-enthusiasm for unlikely() in libata-scsi.c.

Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

libata-acpi: add ata port runtime D3Cold support

ATA port may support runtime D3Cold state, for example, Zero-power ODD case.
This patch adds wakeup notifier and enable/disable run_wake during
supend/resume.

Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

[SCSI] libsas, libata: fix start of life for a sas ata_port

This changes the ordering of initialization and probing events from:
1/ allocate rphy in PORTE_BYTES_DMAED, DISCE_REVALIDATE_DOMAIN
2/ allocate ata_port and schedule port probe in DISCE_PROBE
...to:
1/ allocate ata_port in PORTE_BYTES_DMAED, DISCE_REVALIDATE_DOMAIN
2/ allocate rphy in PORTE_BYTES_DMAED, DISCE_REVALIDATE_DOMAIN
3/ schedule port probe in DISCE_PROBE

This ordering prevents PHYE_SIGNAL_LOSS_EVENTS from sneaking in to
destrory ata devices before they have been fully initialized:

BUG: unable to handle kernel paging request at 0000000000003b10
IP: [<ffffffffa0053d7e>] sas_ata_end_eh+0x12/0x5e [libsas]
...
[<ffffffffa004d1af>] sas_unregister_common_dev+0x78/0xc9 [libsas]
[<ffffffffa004d4d4>] sas_unregister_dev+0x4f/0xad [libsas]
[<ffffffffa004d5b1>] sas_unregister_domain_devices+0x7f/0xbf [libsas]
[<ffffffffa004c487>] sas_deform_port+0x61/0x1b8 [libsas]
[<ffffffffa004bed0>] sas_phye_loss_of_signal+0x29/0x2b [libsas]

...and kills the awkward "sata domain_device briefly existing in the
domain without an ata_port" state.

Reported-by: Michal Kosciowski <michal.kosciowski@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Jeff Garzik <jgarzik@redhat.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] libata: Pass correct DMA device to scsi host

Use scsi_add_host_with_dma in ata_scsi_add_hosts to pass in the
correct DMA device(ATA host).

Bug report: http://marc.info/?l=linux-ide&m=133177818318187&w=2

Reported-and-tested-by: Jörg Sommer <joerg@alea.gnuu.de>
Acked-by: Jeff Garzik <jgarzik@redhat.com>
Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

libata: make ata_print_id atomic

This variable is incremented from multiple contexts (module_init via
libata-lldds and the libsas discovery thread). Make it atomic to head
off any chance of libsas and libata creating duplicate ids.

Acked-by: Jacek Danecki <jacek.danecki@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

[SCSI] libsas: async ata scanning

libsas ata error handling is already async but this does not help the
scan case. Move initial link recovery out from under host->scan_mutex,
and delay synchronization with eh until after all port probe/recovery
work has been queued.

Device ordering is maintained with scan order by still calling
sas_rphy_add() in order of domain discovery.

Since we now scan the domain list when invoking libata-eh we need to be
careful to check for fully initialized ata ports.

Acked-by: Jack Wang <jack_wang@usish.com>
Acked-by: Jeff Garzik <jgarzik@redhat.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

ata: add ata port runtime PM callbacks

Add ata port runtime suspend/resume/idle callbacks.
Set ->eh_noresume to skip the runtime PM calls on scsi host
in the error handler to avoid dead lock.

Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

ata: make ata port as parent device of scsi host

Currently, the device tree of ata port and scsi host looks as below,

/sys/devices/pci0000:00/0000:00:1f.2 (ahci controller)
|-- ata1 (ata port)
|-- host0 (scsi host)
|-- target0:0:0 (scsi target)
|-- 0:0:0:0 (disk)

This patch makes ata port as parent device of scsi host, then it becomes

/sys/devices/pci0000:00/0000:00:1f.2 (ahci controller)
|-- ata1 (ata port)
|-- host0 (scsi host)
|-- target0:0:0 (scsi target)
|-- 0:0:0:0 (disk)

With this change, the ata port runtime PM is easier.
For example, the ata port runtime suspend will happen as,

disk suspend --> scsi target suspend --> scsi host suspend --> ata port
suspend.

Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

[libata] libata-scsi.c: Add function parameter documentation

Add the documentation of parameters of ata_change_queue_depth to silence the warning of make xmldocs

Signed-off-by: Marcos paulo de Souza <marcos.mage@gmail.com>
Acked-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

ide/ata: Add export.h for EXPORT_SYMBOL/THIS_MODULE where needed

They were getting this implicitly by an include of module.h
from device.h -- but we are going to clean that up and break
that include chain, so include export.h explicitly now.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

[SCSI] libsas,libata: fix ->change_queue_{depth|type} for sata devices

Pass queue_depth change requests to libata, and prevent queue_type
changes for ATA devices.

Otherwise:
1/ we do not honor the libata specific restrictions on the queue depth
2/ libsas drivers that do not set sdev->tagged_supported are unable to
change the queue_depth of ata devices via sysfs

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Jeff Garzik <jgarzik@redhat.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

ata: Convert ata_<foo>_printk(KERN_<LEVEL> to ata_<foo>_<level>

Saves text by removing nearly duplicated text format strings by
creating ata_<foo>_printk functions and printf extension %pV.

ata defconfig size shrinks ~5% (~8KB), allyesconfig ~2.5% (~13KB)

Format string duplication comes from:

#define ata_link_printk(link, lv, fmt, args...) do { \
if (sata_pmp_attached((link)->ap) || (link)->ap->slave_link) \
printk("%sata%u.%02u: "fmt, lv, (link)->ap->print_id, \
(link)->pmp , ##args); \
else \
printk("%sata%u: "fmt, lv, (link)->ap->print_id , ##args); \
} while(0)

Coalesce long formats.

$ size drivers/ata/built-in.*
text data bss dec hex filename
544969 73893 116584 735446 b38d6 drivers/ata/built-in.allyesconfig.ata.o
558429 73893 117864 750186 b726a drivers/ata/built-in.allyesconfig.dev_level.o
141328 14689 4220 160237 271ed drivers/ata/built-in.defconfig.ata.o
149567 14689 4220 168476 2921c drivers/ata/built-in.defconfig.dev_level.o

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>

libata/sas: only set FROZEN flag if new EH is supported

On 16.06.2011 [08:28:39 -0500], Brian King wrote:
> On 06/16/2011 02:51 AM, Tejun Heo wrote:
> > On Wed, Jun 15, 2011 at 04:34:17PM -0700, Nishanth Aravamudan wrote:
> >>> That looks like the right thing to do. For ipr's usage of
> >>> libata, we don't have the concept of a port frozen state, so this flag
> >>> should really never get set. The alternate way to fix this would be to
> >>> only set ATA_PFLAG_FROZEN in ata_port_alloc if ap->ops->error_handler
> >>> is not NULL.
> >>
> >> It seemed like ipr is as you say, but I wasn't sure if it was
> >> appropriate to make the change above in the common libata-scis code or
> >> not. I don't want to break some other device on accident.
> >>
> >> Also, I tried your suggestion, but I don't think that can happen in
> >> ata_port_alloc? ata_port_alloc is allocated ap itself, and it seems like
> >> ap->ops typically gets set only after ata_port_alloc returns?
> >
> > Maybe we can test error_handler in ata_sas_port_start()?
>
> Good point. Since libsas is converted to the new eh now, we would need to have
> this test.

Commit 7b3a24c57d2eeda8dba9c205342b12689c4679f9 ("ahci: don't enable
port irq before handler is registered") caused a regression for CD-ROMs
attached to the IPR SATA bus on Power machines:

ata_port_alloc: ENTER
ata_port_probe: ata1: bus probe begin
ata1.00: ata_dev_read_id: ENTER
ata1.00: failed to IDENTIFY (I/O error, err_mask=0x40)
ata1.00: ata_dev_read_id: ENTER
ata1.00: failed to IDENTIFY (I/O error, err_mask=0x40)
ata1.00: limiting speed to UDMA7:PIO5
ata1.00: ata_dev_read_id: ENTER
ata1.00: failed to IDENTIFY (I/O error, err_mask=0x40)
ata1.00: disabled
ata_port_probe: ata1: bus probe end
scsi_alloc_sdev: Allocation failure during SCSI scanning, some SCSI devices might not be configured

The FROZEN flag added in that commit is only cleared by the new EH code,
which is not used by ipr. Clear this flag in the SAS code if we don't
support new EH.

Reported-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>

libata: Use Maximum Write Same Length to report discard size limit

Previously we used Maximum Unmap LBA Count in the Block Limits VPD to
signal the maximum number of sectors we could handle in a single Write
Same command.

Starting with SBC3r26 the Block Limits VPD has an explicit limit on the
number of blocks in a Write Same. This means we can stop abusing a field
related to the Unmap command and let our SAT use the proper value in the
VPD (Maximum Write Same Length).

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>
Cc: stable@kernel.org

SATA: enable non-queueable flush flag

Enable non-queueable flush flag for SATA.

Stable: 2.6.39 only

Cc: stable@kernel.org
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: Jeff Garzik <jgarzik@redhat.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

Fix common misspellings

Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>

libata: Include WWN ID in inquiry VPD emulation

As per SAT-3 the WWN ID should be included in the VPD page 0x83
(device identification) emulation.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>

libata: fix locking for sas paths

For historical reasons, libsas uses the scsi host lock as the ata port
lock, and libata always uses the ata host. For the old eh, this was
largely irrelevant since the two locks were never mixed inside the
code. However, the new eh has a case where it nests acquisition of
the host lock inside the port lock (this does look rather deadlock
prone). Obviously this would be an instant deadlock if the port lock
were the host lock, so switch the libsas paths to use the ata host
lock as well.

Signed-off-by: James Bottomley <James.Bottomley@suse.de>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

libata: plumb sas port scan into standard libata paths

The function ata_sas_port_init() has always really done its own thing.
However, as a precursor to moving to the libata new eh, it has to be
properly using the standard libata scan paths. This means separating
the current libata scan paths into pieces which can be shared with
libsas and pieces which cant (really just the async call and the host
scan).

Signed-off-by: James Bottomley <James.Bottomley@suse.de>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

[SCSI] libata: fix locking for sas paths

For historical reasons, libsas uses the scsi host lock as the ata port
lock, and libata always uses the ata host. For the old eh, this was
largely irrelevant since the two locks were never mixed inside the
code. However, the new eh has a case where it nests acquisition of
the host lock inside the port lock (this does look rather deadlock
prone). Obviously this would be an instant deadlock if the port lock
were the host lock, so switch the libsas paths to use the ata host
lock as well.

Cc: Tejun Heo <tj@kernel.org>
Cc: Jeff Garzik <jeff@garzik.org>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] libata: plumb sas port scan into standard libata paths

The function ata_sas_port_init() has always really done its own thing.
However, as a precursor to moving to the libata new eh, it has to be
properly using the standard libata scan paths. This means separating
the current libata scan paths into pieces which can be shared with
libsas and pieces which cant (really just the async call and the host
scan).

Cc: Tejun Heo <tj@kernel.org>
Cc: Jeff Garzik <jeff@garzik.org>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

libata: set queue DMA alignment to sector size for ATAPI too

ata_pio_sectors() expects buffer for each sector to be contained in a
single page; otherwise, it ends up overrunning the first page. This
is achieved by setting queue DMA alignment. If sector_size is smaller
than PAGE_SIZE and all buffers are sector_size aligned, buffer for
each sector is always contained in a single page.

This wasn't applied to ATAPI devices but IDENTIFY_PACKET is executed
as ATA_PROT_PIO and thus uses ata_pio_sectors(). Newer versions of
udev issue IDENTIFY_PACKET with unaligned buffer triggering the
problem and causing oops.

This patch fixes the problem by setting sdev->sector_size to
ATA_SECT_SIZE on ATATPI devices and always setting DMA alignment to
sector_size. While at it, add a warning for the unlikely but still
possible scenario where sector_size is larger than PAGE_SIZE, in which
case the alignment wouldn't be enough.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: John Stanley <jpsinthemix@verizon.net>
Tested-by: John Stanley <jpsinthemix@verizon.net>
Cc: stable@kernel.org
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

[libata] avoid needlessly passing around ptr to SCSI completion func

It's stored in struct scsi_cmnd->scsi_done, making several 'done'
parameters to functions redundant.

Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

[libata] remove SCSI host lock and serial number usage from ata_scsi_queuecmd

cmd->serial_number is never tested in any path we reach; therefore we may
remove the call to scsi_cmd_get_serial() inside DEF_SCSI_QCMD, the SCSI
host_lock acquisition surrounding it, and our own SCSI host_lock
unlock+relock cycle.

Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

SCSI host lock push-down

Move the mid-layer's ->queuecommand() invocation from being locked
with the host lock to being unlocked to facilitate speeding up the
critical path for drivers who don't need this lock taken anyway.

The patch below presents a simple SCSI host lock push-down as an
equivalent transformation. No locking or other behavior should change
with this patch. All existing bugs and locking orders are preserved.

Additionally, add one parameter to queuecommand,
struct Scsi_Host *
and remove one parameter from queuecommand,
void (*done)(struct scsi_cmnd *)

Scsi_Host* is a convenient pointer that most host drivers need anyway,
and 'done' is redundant to struct scsi_cmnd->scsi_done.

Minimal code disturbance was attempted with this change. Most drivers
needed only two one-line modifications for their host lock push-down.

Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Acked-by: James Bottomley <James.Bottomley@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

libata: fix NULL sdev dereference race in atapi_qc_complete()

SCSI commands may be issued between __scsi_add_device() and dev->sdev
assignment, so it's unsafe for ata_qc_complete() to dereference
dev->sdev->locked without checking whether it's NULL or not. Fix it.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: stable@kernel.org
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

libata: Signal that our SATL supports WRITE SAME(16) with UNMAP

Until now identifying that a device supports WRITE SAME(16) with the
UNMAP bit set has been black magic. Implement support for the SBC-3
Thin Provisioning VPD page and set the TPWS bit.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

libata: reimplement link power management

The current LPM implementation has the following issues.

* Operation order isn't well thought-out. e.g. HIPM should be
configured after IPM in SControl is properly configured. Not the
other way around.

* Suspend/resume paths call ata_lpm_enable/disable() which must only
be called from EH context directly. Also, ata_lpm_enable/disable()
were called whether LPM was in use or not.

* Implementation is per-port when it should be per-link. As a result,
it can't be used for controllers with slave links or PMP.

* LPM state isn't managed consistently. After a link reset for
whatever reason including suspend/resume the actual LPM state would
be reset leaving ap->lpm_policy inconsistent.

* Generic/driver-specific logic boundary isn't clear. Currently,
libahci has to mangle stuff which libata EH proper should be
handling. This makes the implementation unnecessarily complex and
fragile.

* Tied to ALPM. Doesn't consider DIPM only cases and doesn't check
whether the device allows HIPM.

* Error handling isn't implemented.

Given the extent of mismatch with the rest of libata, I don't think
trying to fix it piecewise makes much sense. This patch reimplements
LPM support.

* The new implementation is per-link. The target policy is still
port-wide (ap->target_lpm_policy) but all the mechanisms and states
are per-link and integrate well with the rest of link abstraction
and can work with slave and PMP links.

* Core EH has proper control of LPM state. LPM state is reconfigured
when and only when reconfiguration is necessary. It makes sure that
LPM state is reset when probing for new device on the link.
Controller agnostic logic is now implemented in libata EH proper and
driver implementation only has to deal with controller specifics.

* Proper error handling. LPM config failure is attributed to the
device on the link and LPM is disabled for the link if it fails
repeatedly.

* ops->enable/disable_pm() are replaced with single ops->set_lpm()
which takes @policy and @hints. This simplifies driver specific
implementation.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

libata: clean up lpm related symbols and sysfs show/store functions

Link power management related symbols are in confusing state w/ mixed
usages of lpm, ipm and pm. This patch cleans up lpm related symbols
and sysfs show/store functions as follows.

* lpm states - NOT_AVAILABLE, MIN_POWER, MAX_PERFORMANCE and
MEDIUM_POWER are renamed to ATA_LPM_UNKNOWN and
ATA_LPM_{MIN|MAX|MED}_POWER.

* Pre/postfixes are unified to lpm.

* sysfs show/store functions for link_power_management_policy were
curiously named get/put and unnecessarily complex. Renamed to
show/store and simplified.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

[libata] support for > 512 byte sectors (e.g. 4K Native)

This change enables my x86 machine to recognize and talk to a
"Native 4K" SATA device.

When I started working on this, I didn't know Matthew Wilcox had
posted a similar patch 2 years ago:
http://git.kernel.org/?p=linux/kernel/git/willy/ata.git;a=shortlog;h=refs/heads/ata-large-sectors

Gwendal Grignou pointed me at the the above code and small portions of
this patch include Matthew's work. That's why Mathew is first on the
"Signed-off-by:". I've NOT included his use of a bitmap to determine
512 vs Native for ATA command block size - just used a simple table.
And bugs are almost certainly mine.

Lastly, the patch has been tested with a native 4K 'Engineering
Sample' drive provided by Hitachi GST.

Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
Signed-off-by: Grant Grundler <grundler@google.com>
Reviewed-by: Gwendal Grignou <gwendal@google.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

[libata] Add ATA transport class

This is a scheleton for libata transport class.
All information is read only, exporting information from libata:
- ata_port class: one per ATA port
- ata_link class: one per ATA port or 15 for SATA Port Multiplier
- ata_device class: up to 2 for PATA link, usually one for SATA.

Signed-off-by: Gwendal Grignou <gwendal@google.com>
Reviewed-by: Grant Grundler <grundler@google.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

block: unify flags for struct bio and struct request

Remove the current bio flags and reuse the request flags for the bio, too.
This allows to more easily trace the type of I/O from the filesystem
down to the block driver. There were two flags in the bio that were
missing in the requests: BIO_RW_UNPLUG and BIO_RW_AHEAD. Also I've
renamed two request flags that had a superflous RW in them.

Note that the flags are in bio.h despite having the REQ_ name - as
blkdev.h includes bio.h that is the only way to go for now.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

block: remove wrappers for request type/flags

Remove all the trivial wrappers for the cmd_type and cmd_flags fields in
struct requests. This allows much easier grepping for different request
types instead of unwinding through macros.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

libata: take advantage of cmwq and remove concurrency limitations

libata has two concurrency related limitations.

a. ata_wq which is used for polling PIO has single thread per CPU. If
there are multiple devices doing polling PIO on the same CPU, they
can't be executed simultaneously.

b. ata_aux_wq which is used for SCSI probing has single thread. In
cases where SCSI probing is stalled for extended period of time
which is possible for ATAPI devices, this will stall all probing.

#a is solved by increasing maximum concurrency of ata_wq. Please note
that polling PIO might be used under allocation path and thus needs to
be served by a separate wq with a rescuer.

#b is solved by using the default wq instead and achieving exclusion
via per-port mutex.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Jeff Garzik <jgarzik@pobox.com>

libata: implement on-demand HPA unlocking

Implement ata_scsi_unlock_native_capacity() which will be called
through SCSI layer when block layer notices that partitions on a
device extend beyond the end of the device. It requests EH to unlock
HPA, waits for completion and returns the current device capacity.

This allows libata to unlock HPA on demand instead of having to decide
whether to unlock upfront. Unlocking on demand is safer than
unlocking by upfront because some BIOSes write private data to the
area beyond HPA limit. This was suggested by Ben Hutchings.

Signed-off-by: Tejun Heo <tj@kernel.org>
Suggested-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

libata: kill ATA_FLAG_DISABLED

ATA_FLAG_DISABLED is only used by drivers which don't use
->error_handler framework and is largely broken. Its only meaningful
function is to make irq handlers skip processing if the flag is set,
which is largely useless and even harmful as it makes those ports more
likely to cause IRQ storms.

Kill ATA_FLAG_DISABLED and makes the callers disable attached devices
instead. ata_port_probe() and ata_port_disable() which manipulate the
flag are also killed.

This simplifies condition check in IRQ handlers. While updating IRQ
handlers, remove ap NULL check as libata guarantees consecutive port
allocation (unoccupied ports are initialized with dummies) and
long-obsolete ATA_QCFLAG_ACTIVE check (checked by ata_qc_from_tag()).

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h

percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.

2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).

* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>