linux-stable.git/include/linux/libata.h, branch v6.1.55

ata: libata: disallow dev-initiated LPM transitions to unsupported states

2023-09-23T09:11:12+00:00

commit 24e0e61db3cb86a66824531989f1df80e0939f26 upstream.

In AHCI 1.3.1, the register description for CAP.SSC:
"When cleared to ‘0’, software must not allow the HBA to initiate
transitions to the Slumber state via agressive link power management nor
the PxCMD.ICC field in each port, and the PxSCTL.IPM field in each port
must be programmed to disallow device initiated Slumber requests."

In AHCI 1.3.1, the register description for CAP.PSC:
"When cleared to ‘0’, software must not allow the HBA to initiate
transitions to the Partial state via agressive link power management nor
the PxCMD.ICC field in each port, and the PxSCTL.IPM field in each port
must be programmed to disallow device initiated Partial requests."

Ensure that we always set the corresponding bits in PxSCTL.IPM, such that
a device is not allowed to initiate transitions to power states which are
unsupported by the HBA.

DevSleep is always initiated by the HBA, however, for completeness, set the
corresponding bit in PxSCTL.IPM such that agressive link power management
cannot transition to DevSleep if DevSleep is not supported.

sata_link_scr_lpm() is used by libahci, ata_piix and libata-pmp.
However, only libahci has the ability to read the CAP/CAP2 register to see
if these features are supported. Therefore, in order to not introduce any
regressions on ata_piix or libata-pmp, create flags that indicate that the
respective feature is NOT supported. This way, the behavior for ata_piix
and libata-pmp should remain unchanged.

This change is based on a patch originally submitted by Runa Guo-oc.

Signed-off-by: Niklas Cassel 
Fixes: 1152b2617a6e ("libata: implement sata_link_scr_lpm() and make ata_dev_set_feature() global")
Cc: stable@vger.kernel.org
Signed-off-by: Damien Le Moal 
Signed-off-by: Greg Kroah-Hartman

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

2023-06-28T09:12:17+00:00

[ Upstream commit 6aa0365a3c8512587fffd42fe438768709ddef8e ]

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 
Reported-by: Joe Breuer 
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 
Reviewed-by: Hannes Reinecke 
Tested-by: Kai-Heng Feng 
Tested-by: Joe Breuer 
Signed-off-by: Sasha Levin

Merge tag 'ata-6.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/dlemoal/libata

2022-10-07T17:48:49+00:00

Pull ata updates from Damien Le Moal:

 - Print the timeout value for internal command failures due to a
   timeout (from Tomas)

 - Improve parameter names in ata_dev_set_feature() to clarify this
   function use (from Niklas)

 - Improve the ahci driver low power mode setting initialization to
   allow more flexibility for the user (from Rafael)

 - Several patches to remove redundant variables in libata-core,
   libata-eh and the pata_macio driver and to fix typos in comments
   (from Jinpeng, Shaomin, Ye)

 - Some code simplifications and macro renaming (for clarity) in various
   functions of libata-core (from me)

 - Add a missing check for a potential failure of sata_scr_read() in
   sata_print_link_status() (from Li)

 - Cleanup of libata Kconfig PATA_PLATFORM and PATA_OF_PLATFORM options
   (from Lukas)

 - Cleanups of ata dt-bindings and improvements of libahci_platform,
   ahci and libahci code (from Serge)

 - New driver for Synopsys AHCI SATA controllers, based of the generic
   ahci code (from Serge). One compilation warning fix is added for this
   driver (from me)

 - Several fixes to macros used to discover a drive capabilities to be
   consistent with the ACS specifications (from Niklas)

 - A couple of simplifcations to some libata functions, removing
   unnecessary arguments (from Niklas)

 - An improvements to libata-eh code to avoid unnecessary link reset
   when revalidating a drive after a failed command. In practice, this
   extra, unneeded reset, reset does not cause any arm beyond slightly
   slowing down error recovery (from Niklas)

* tag 'ata-6.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/dlemoal/libata: (45 commits)
  ata: libata-eh: avoid needless hard reset when revalidating link
  ata: libata: drop superfluous ata_eh_analyze_tf() parameter
  ata: libata: drop superfluous ata_eh_request_sense() parameter
  ata: fix ata_id_has_dipm()
  ata: fix ata_id_has_ncq_autosense()
  ata: fix ata_id_has_devslp()
  ata: fix ata_id_sense_reporting_enabled() and ata_id_has_sense_reporting()
  ata: libata-eh: Remove the unneeded result variable
  ata: ahci_st: Enable compile test
  ata: ahci_st: Fix compilation warning
  MAINTAINERS: Add maintainers for DWC AHCI SATA driver
  ata: ahci-dwc: Add Baikal-T1 AHCI SATA interface support
  ata: ahci-dwc: Add platform-specific quirks support
  dt-bindings: ata: ahci: Add Baikal-T1 AHCI SATA controller DT schema
  ata: ahci: Add DWC AHCI SATA controller support
  ata: libahci_platform: Add function returning a clock-handle by id
  dt-bindings: ata: ahci: Add DWC AHCI SATA controller DT schema
  ata: ahci: Introduce firmware-specific caps initialization
  ata: ahci: Convert __ahci_port_base to accepting hpriv as arguments
  ata: libahci: Don't read AHCI version twice in the save-config method
  ...

ata: libata-sata: Fix device queue depth control

2022-09-28T11:47:31+00:00

The function __ata_change_queue_depth() uses the helper
ata_scsi_find_dev() to get the ata_device structure of a scsi device and
set that device maximum queue depth. However, when the ata device is
managed by libsas, ata_scsi_find_dev() returns NULL, turning
__ata_change_queue_depth() into a nop, which prevents the user from
setting the maximum queue depth of ATA devices used with libsas based
HBAs.

Fix this by renaming __ata_change_queue_depth() to
ata_change_queue_depth() and adding a pointer to the ata_device
structure of the target device as argument. This pointer is provided by
ata_scsi_change_queue_depth() using ata_scsi_find_dev() in the case of
a libata managed device and by sas_change_queue_depth() using
sas_to_ata_dev() in the case of a libsas managed ata device.

Signed-off-by: Damien Le Moal 
Tested-by: John Garry

ata: libata: Rename ATA_DFLAG_NCQ_PRIO_ENABLE

2022-08-25T22:46:08+00:00

Rename ATA_DFLAG_NCQ_PRIO_ENABLE to ATA_DFLAG_NCQ_PRIO_ENABLED to match
the fact that this flags indicates if NCQ priority use is enabled by the
user.

Signed-off-by: Damien Le Moal

ata: libata: Set __ATA_BASE_SHT max_sectors

2022-08-20T16:29:50+00:00

Commit 0568e6122574 ("ata: libata-scsi: cap ata_device->max_sectors
according to shost->max_sectors") inadvertently capped the max_sectors
value for some SATA disks to a value which is lower than we would want.

For a device which supports LBA48, we would previously have request queue
max_sectors_kb and max_hw_sectors_kb values of 1280 and 32767 respectively.

For AHCI controllers, the value chosen for shost max sectors comes from
the minimum of the SCSI host default max sectors in
SCSI_DEFAULT_MAX_SECTORS (1024) and the shost DMA device mapping limit.

This means that we would now set the max_sectors_kb and max_hw_sectors_kb
values for a disk which supports LBA48 at 512, ignoring DMA mapping limit.

As report by Oliver at [0], this caused a performance regression.

Fix by picking a large enough max sectors value for ATA host controllers
such that we don't needlessly reduce max_sectors_kb for LBA48 disks.

[0] https://lore.kernel.org/linux-ide/YvsGbidf3na5FpGb@xsang-OptiPlex-9020/T/#m22d9fc5ad15af66066dd9fecf3d50f1b1ef11da3

Fixes: 0568e6122574 ("ata: libata-scsi: cap ata_device->max_sectors according to shost->max_sectors")
Reported-by: Oliver Sang 
Signed-off-by: John Garry 
Signed-off-by: Damien Le Moal

ata: make ata_port::fastdrain_cnt unsigned int

2022-06-19T23:17:33+00:00

*unsigned long* ata_port::fastdrain_cnt (64-bit value in a 64-bit kernel)
is always assigned from the 32-bit *unsigned int* variables, thus could
also be made just *unsigned int*...

Signed-off-by: Sergey Shtylyov 
Signed-off-by: Damien Le Moal

ata: make transfer mode masks unsigned int

2022-06-17T07:35:02+00:00

The packed transfer mode masks and also the {pio|mwdma|udma}_mask fields
of *struct*s ata_device and ata_port_info are declared as *unsigned long*
(which is a 64-bit type on 64-bit architectures) but actually the packed
masks occupy only 20 bits (7 PIO modes, 5 MWDMA modes, and 8 UDMA modes)
and the PIO/MWDMA/UDMA masks easily fit into just 8 bits each, so we can
safely use (always 32-bit) *unsigned int* variables instead.  This saves
745 bytes of object code in libata-core.o alone, not to mention LLDDs...

Signed-off-by: Sergey Shtylyov 
Signed-off-by: Damien Le Moal

ata: libata: drop 'sas_last_tag'

2022-06-06T00:52:17+00:00

Unused now.

Fixes: 4f1a22ee7b57 ("libata: Improve ATA queued command allocation")
Cc: John Garry 
Signed-off-by: Hannes Reinecke 
Reviewed-by: John Garry 
Signed-off-by: Damien Le Moal

ata: libata-core: fix parameter type in ata_xfer_mode2shift()

2022-04-12T00:35:04+00:00

The data transfer mode that corresponds to the 'xfer_mode' parameter for
ata_xfer_mode2shift() is a 8-bit *unsigned* value.  Using *unsigned long*
to declare the parameter leads to a problematic implicit *int* to *unsigned
long* cast and was most probably a result of a copy/paste mistake -- use
the 'u8' type instead, as in ata_xfer_mode2mask()...

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

Signed-off-by: Sergey Shtylyov 
Signed-off-by: Damien Le Moal