linux-toradex.git/include/scsi/libsas.h, branch v3.11.2

[SCSI] libsas: implement > 16 byte CDB support

2013-06-04T18:15:59+00:00

Remove the arbitrary expectation in libsas that all SCSI commands are 16 bytes
or less.  Instead do all copies via cmd->cmd_len (and use a pointer to this in
the libsas task instead of a copy).  Note that this still doesn't enable > 16
byte CDB support in the underlying drivers because their internal format has
to be fixed and the wire format of > 16 byte CDBs according to the SAS spec is
different.  the libsas drivers (isci, aic94xx, mvsas and pm8xxx are all
updated for this change.

Cc: Lukasz Dorau 
Cc: Maciej Patelczyk 
Cc: Dave Jiang 
Cc: Jack Wang 
Cc: Lindar Liu 
Cc: Xiangliang Yu 
Signed-off-by: James Bottomley

[SCSI] sas: unify the pointlessly separated enums sas_dev_type and sas_device_type

2013-05-10T14:47:52+00:00

These enums have been separate since the dawn of SAS, mainly because the
latter is a procotol only enum and the former includes additional state
for libsas.  The dichotomy causes endless confusion about which one you
should use where and leads to pointless warnings like this:

drivers/scsi/mvsas/mv_sas.c: In function 'mvs_update_phyinfo':
drivers/scsi/mvsas/mv_sas.c:1162:34: warning: comparison between 'enum sas_device_type' and 'enum sas_dev_type' [-Wenum-compare]

Fix by eliminating one of them.  The one kept is effectively the sas.h
one, but call it sas_device_type and make sure the enums are all
properly namespaced with the SAS_ prefix.

Signed-off-by: James Bottomley

[SCSI] libsas: suspend / resume support

2012-08-24T09:10:23+00:00

libsas power management routines to suspend and recover the sas domain
based on a model where the lldd is allowed and expected to be
"forgetful".

sas_suspend_ha - disable event processing allowing the lldd to take down
                 links without concern for causing hotplug events.
                 Regardless of whether the lldd actually posts link down
                 messages libsas notifies the lldd that all
                 domain_devices are gone.

sas_prep_resume_ha - on the way back up before the lldd starts link
                     training clean out any spurious events that were
                     generated on the way down, and re-enable event
                     processing

sas_resume_ha - after the lldd has started and decided that all phys
		have posted link-up events this routine is called to let
		libsas start it's own timeout of any phys that did not
		resume.  After the timeout an lldd can cancel the
                phy teardown by posting a link-up event.

Storage for ex_change_count (u16) and phy_change_count (u8) are changed
to int so they can be set to -1 to indicate 'invalidated'.

Signed-off-by: Dan Williams 
Reviewed-by: Jacek Danecki 
Tested-by: Maciej Patelczyk 
Acked-by: Alan Stern 
Signed-off-by: James Bottomley

[SCSI] libsas: trim sas_task of slow path infrastructure

2012-07-20T07:58:54+00:00

The timer and the completion are only used for slow path tasks (smp, and
lldd tmfs), yet we incur the allocation space and cpu setup time for
every fast path task.

Cc: Xiangliang Yu 
Acked-by: Jack Wang 
Signed-off-by: Dan Williams 
Signed-off-by: James Bottomley

[SCSI] libsas: drop sata port multiplier infrastructure

2012-07-20T07:58:53+00:00

On the way to add a new sata_device field, noticed that libsas is
carrying port multiplier infrastructure that is explicitly disabled by
sas_discover_sata().  The aic94xx touches the unused port_no, so leave
that field in case there was some use for it.

Signed-off-by: Dan Williams 
Signed-off-by: James Bottomley

[SCSI] libsas: add sas_eh_abort_handler

2012-07-20T07:58:50+00:00

When recovering failed eh-cmnds let the lldd attempt an abort via
scsi_abort_eh_cmnd before escalating.

Reviewed-by: Jacek Danecki 
Signed-off-by: Dan Williams 
Signed-off-by: James Bottomley

[SCSI] libsas: enforce eh strategy handlers only in eh context

2012-07-20T07:58:50+00:00

The strategy handlers may be called in places that are problematic for
libsas (i.e. sata resets outside of domain revalidation filtering /
libata link recovery), or problematic for userspace (non-blocking ioctl
to sleeping reset functions).  However, these routines are also called
for eh escalations and recovery of scsi_eh_prep_cmnd(), so permit them
as long as we are running in the host's error handler, otherwise arrange
for them to be triggered in eh_context.

Signed-off-by: Dan Williams 
Signed-off-by: James Bottomley

[SCSI] libata, libsas: introduce sched_eh and end_eh port ops

2012-07-20T07:58:45+00:00

When managing shost->host_eh_scheduled libata assumes that there is a
1:1 shost-to-ata_port relationship.  libsas creates a 1:N relationship
so it needs to manage host_eh_scheduled cumulatively at the host level.
The sched_eh and end_eh port port ops allow libsas to track when domain
devices enter/leave the "eh-pending" state under ha->lock (previously
named ha->state_lock, but it is no longer just a lock for ha->state
changes).

Since host_eh_scheduled indicates eh without backing commands pinning
the device it can be deallocated at any time.  Move the taking of the
domain_device reference under the port_lock to guarantee that the
ata_port stays around for the duration of eh.

Reviewed-by: Jacek Danecki 
Acked-by: Jeff Garzik 
Signed-off-by: Dan Williams 
Signed-off-by: James Bottomley

[SCSI] libsas: fix taskfile corruption in sas_ata_qc_fill_rtf

2012-07-08T08:49:14+00:00

fill_result_tf() grabs the taskfile flags from the originating qc which
sas_ata_qc_fill_rtf() promptly overwrites.  The presence of an
ata_taskfile in the sata_device makes it tempting to just copy the full
contents in sas_ata_qc_fill_rtf().  However, libata really only wants
the fis contents and expects the other portions of the taskfile to not
be touched by ->qc_fill_rtf.  To that end store a fis buffer in the
sata_device and use ata_tf_from_fis() like every other ->qc_fill_rtf()
implementation.

Cc: 
Reported-by: Praveen Murali 
Tested-by: Praveen Murali 
Signed-off-by: Dan Williams 
Signed-off-by: James Bottomley

[SCSI] libsas: introduce sas_work to fix sas_drain_work vs sas_queue_work

2012-04-23T11:03:39+00:00

When requeuing work to a draining workqueue the last work instance may
not be idle, so sas_queue_work() must not touch work->entry.  Introduce
sas_work with a drain_node list_head to have a private list for
collecting work deferred due to drain collision.

Fixes reports like:
  BUG: unable to handle kernel NULL pointer dereference at           (null)
  IP: [] process_one_work+0x2e/0x338

Signed-off-by: Dan Williams 
Signed-off-by: James Bottomley