linux-toradex.git/include/scsi/libsas.h, branch v3.2.42

libsas: fix taskfile corruption in sas_ata_qc_fill_rtf

2012-07-25T03:11:12+00:00

commit 6ef1b512f4e6f936d89aa20be3d97a7ec7c290ac upstream.

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.

Reported-by: Praveen Murali 
Tested-by: Praveen Murali 
Signed-off-by: Dan Williams 
Signed-off-by: James Bottomley 
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings

[SCSI] libsas: fix port->dev_list locking

2011-10-16T15:54:02+00:00

port->dev_list maintains a list of devices attached to a given sas root port.
It needs to be mutated under a lock as contexts outside of the
single-threaded-libsas-workqueue access the list via sas_find_dev_by_rphy().
Fixup locations where the list was being mutated without a lock.

This is a follow-up to commit 5911e963 "[SCSI] libsas: remove expander
from dev list on error", where Luben noted [1]:

    > 2/ We have unlocked list manipulations in sas_ex_discover_end_dev(),
    > sas_unregister_common_dev(), and sas_ex_discover_end_dev()

    Yes, I can see that and that is very unfortunate.

[1]: http://marc.info/?l=linux-scsi&m=131480962006471&w=2

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

[SCSI] isci: atapi support

2011-10-02T18:20:03+00:00

Based on original implementation from Jiangbi Liu and Maciej Trela.

ATAPI transfers happen in two-to-three stages.  The two stage atapi
commands are those that include a dma data transfer.  The data transfer
portion of these operations is handled by the hardware packet-dma
acceleration.  The three-stage commands do not have a data transfer and
are handled without hardware assistance in raw frame mode.

stage1: transmit host-to-device fis to notify the device of an incoming
atapi cdb.  Upon reception of the pio-setup-fis repost the task_context
to perform the dma transfer of the cdb+data (go to stage3), or repost
the task_context to transmit the cdb as a raw frame (go to stage 2).

stage2: wait for hardware notification of the cdb transmission and then
go to stage 3.

stage3: wait for the arrival of the terminating device-to-host fis and
terminate the command.

To keep the implementation simple we only support ATAPI packet-dma
protocol (for commands with data) to avoid needing to handle the data
transfer manually (like we do for SATA-PIO).  This may affect
compatibility for a small number of devices (see
ATA_HORKAGE_ATAPI_MOD16_DMA).

If the data-transfer underruns, or encounters an error the
device-to-host fis is expected to arrive in the unsolicited frame queue
to pass to libata for disposition.  However, in the DONE_UNEXP_FIS (data
underrun) case it appears we need to craft a response.  In the
DONE_REG_ERR case we do receive the UF and propagate it to libsas.

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

[SCSI] libsas: fix try_test_sas_gpio_gp_bit() build error

2011-10-02T17:47:40+00:00

If the user has disabled CONFIG_SCSI_SAS_HOST_SMP then libsas drivers
will not be receiving smp-gpio frames and do not need this lookup code.

Reported-by: Randy Dunlap 
Tested-by: Randy Dunlap 
Signed-off-by: Dan Williams 
Signed-off-by: James Bottomley

[SCSI] libsas: Allow expander T-T attachments

2011-10-02T17:23:11+00:00

Allow expander table-to-table attachments for
expanders that support it.

Signed-off-by: Luben Tuikov 
Signed-off-by: James Bottomley

[SCSI] libsas: sgpio write support

2011-09-22T10:59:09+00:00

Add SFF-8485 v0.7 / SAS-1 smp-write-gpio register support to libsas.
Defer SAS-2 support unless/until it defines an sgpio interface.

Minimum implementation needed to get the lights blinking.
try_test_sas_gpio_gp_bit() provides a common method to parse the
incoming write data (raw bitstream), and the to_sas_gpio_gp_bit() helper
routine can be used as a basis for the set/clear operations for the
'read' implementation.  Host implementations parse as many bits
(ODx.[012]) as are locally supported and report the number of registers
successfully written.  If the submitted data overruns the internal
number of registers available report the write as a success with the
number of bytes remaining reported in ->resid_len.

Example (assuming an active backplane) set the "identify" pattern for
the first 21 devices:

smp_write_gpio --count=2 --data=92,49,24,92,24,92,49,24 -t 4 --index=1 /dev/bsg/sas_hostX

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

[SCSI] libsas: export sas_alloc_task()

2011-08-27T14:35:13+00:00

Now that isci has added a 3rd open coded user of this functionality just
share the libsas version.

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

[SCSI] libsas: Add option for SATA soft reset

2011-05-27T03:49:33+00:00

This allows a libsas driver to optionally provide a soft reset handler
for libata to drive.  The isci driver allows software to control the
assertion/deassertion of SRST.

[jejb: checkpatch.pl fixes]
Signed-off-by: Dave Jiang 
Signed-off-by: Dan Williams 
Signed-off-by: James Bottomley

[SCSI] libsas: fix definition of wideport, include local sas address

2010-12-21T18:23:53+00:00

To date libsas has only looked at the attached sas address when
determining the formation of wide ports.  The specification and some
hardware expects that phys with different addresses will not form a wide
port unless the local peer phys also match each other.  Introduce a flag
to select stricter behavior at sas_register_ha() time.  The flag can be
dropped once it is known that all libsas users expect the same behavior.

Current drivers just initialize this field to zero and get the
traditional behavior.

Reported-by: Patrick Thomson 
Signed-off-by: Dan Williams 
Signed-off-by: James Bottomley

SCSI host lock push-down

2010-11-16T21:33:23+00:00

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 
Acked-by: James Bottomley 
Signed-off-by: Linus Torvalds