ata_port has two different id fields - id and port_no.  id is
system-wide 1-based unique id for the port while port_no is 0-based
host-wide port number.  The former is primarily used to identify the
ATA port to the user in printk messages while the latter is used in
various places in libata core and LLDs to index the port inside the
host.

The two fields feel quite similar and sometimes ap->id is used in
place of ap->port_no, which is very difficult to spot.  This patch
renames ap->id to ap->print_id to reduce the possibility of such bugs.

Some printk messages are adjusted such that id string (ata%u[.%u])
isn't printed twice and/or to use ata_*_printk() instead of hardcoded
id format.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Fix ata_scsi_change_queue_depth() such that...

* NCQ on/off is exactly determined using the same logic as the issue path.

* queue depth is adjusted to 1 if NCQ is not enabled.

* -EINVAL is returned if requested action is ignored due to limitations.

This fixes the bug which allows queue depth to be increased on
blacklisted NCQ hosts/devices.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Fix ata_scmd_need_defer() such that...

* whether NCQ is used or not is exactly determined using the same
  criteria as the issue path.

* defer-check is performed in all cases.

This fixes race condition where turning off NCQ on the fly causes
non-NCQ commands sneak into NCQ phase.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

ata_probe_ent_alloc() had a temporary hack such that devm_kzalloc()
was used for allocation if devres had been previously initialized on
the device; otherwise, plain kzalloc() was used.  This was to make the
code useable from both the old and devres-aware libata drivers during
transition.  This hack made ata_sas_port_alloc() unable to determine
how the probe_ent is allocated, causing double free in some cases.

Remove the now-unneeded hack and make ata_sas_port_alloc() use
devm_kfree().
Signed-off-by: NTejun Heo <htejun@gmail.com>
Cc: James Bottomley <James.Bottomley@SteelEye.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

I was trying to use HDIO_DRIVE_TASK for something today,
and discovered that the libata implementation does not copy
over the upper four LBA bits from args[6].

This is serious, as any tools using this ioctl would have their
commands applied to the wrong sectors on the drive, possibly resulting
in disk corruption.

Ideally, newer apps should use SG_IO/ATA_16 directly,
avoiding this bug.  But with libata poised to displace drivers/ide,
better compatibility here is a must.

This patch fixes libata to use the upper four LBA bits passed
in from the ioctl.

The original drivers/ide implementation copies over all bits
except for the master/slave select bit.  With this patch,
libata will copy only the four high-order LBA bits,
just in case there are assumptions elsewhere in libata (?).
Signed-Off-By: NMark Lord <mlord@pobox.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Update libata core layer to use devres.

* ata_device_add() acquires all resources in managed mode.

* ata_host is allocated as devres associated with ata_host_release.

* Port attached status is handled as devres associated with
  ata_host_attach_release().

* Initialization failure and host removal is handedl by releasing
  devres group.

* Except for ata_scsi_release() removal, LLD interface remains the
  same.  Some functions use hacky is_managed test to support both
  managed and unmanaged devices.  These will go away once all LLDs are
  updated to use devres.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

'hdparm -I' doesn't work with ATAPI devices and sg_sat is not widely
spread yet leaving no easy way to access ATAPI IDENTIFY data.
Implement HDIO_GET_IDENTITY such that at least 'hdparm -i' works.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

libata used two separate sets of variables to record request size and
current offset for ATA and ATAPI.  This is confusing and fragile.
This patch replaces qc->nsect/cursect with qc->nbytes/curbytes and
kills them.  Also, ata_pio_sector() is updated to use bytes for
qc->cursg_ofs instead of sectors.  The field used to be used in bytes
for ATAPI and in sectors for ATA.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

* Kill _OFS suffixes in ATA_ID_{SERNO|FW_REV|PROD}_OFS for consistency
  with other ATA_ID_* constants.

* Kill ATA_SERNO_LEN

* Add and use ATA_ID_SERNO_LEN, ATA_ID_FW_REV_LEN and ATA_ID_PROD_LEN.
  This change also makes ata_device_blacklisted() use proper length
  for fwrev.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

This patch makes the following needlessly global functions static:
- libata-core.c: ata_qc_complete_internal()
- libata-scsi.c: ata_scsi_qc_new()
- libata-scsi.c: ata_dump_status()
- libata-scsi.c: ata_to_sense_error()
Signed-off-by: NAdrian Bunk <bunk@stusta.de>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

This patch introduces users of the round_jiffies() function: ATA subsystem

This delayed work is of the "about once a second" variety and can be rounded
to coincide with other wakers.
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>
Cc: Jeff Garzik <jeff@garzik.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

libata's SCSI translation for the SCSI START STOP UNIT command with the
START bit clear (i.e.  stopping the drive) appears to be incorrect.  It
sends an ATA STANDBY command with the time period set to 0, which the code
comment says means "now", but the ATA standard says this means disable the
standby timer, which effectively does nothing.  Change this to issue a
STANDBY IMMEDIATE command which will actually spin the drive down.  The SAT
(SCSI/ATA Translation) standard revision 9 concurs with this choice.
Signed-off-by: NRobert Hancock <hancockr@shaw.ca>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

User applications using the HDIO_DRIVE_TASK ioctl through libata expect
specific ATA registers to be returned to userspace.  Verified that
ata_task_ioctl correctly returns register values to the smartctl
application.
Signed-off-by: NDavid Milburn <dmilburn@redhat.com>
Acked-by: NTejun Heo <htejun@gmail.com>
Cc: Jeff Garzik <jeff@garzik.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Fixup the inialization of qc->n_elem. It currently gets
initialized to 1 for commands that do not transfer any data.
Fix this by initializing n_elem to 0 and only setting to 1
in ata_scsi_qc_new when there is data to transfer. This fixes
some problems seen with SATA devices attached to ipr adapters.
Signed-off-by: NBrian King <brking@linux.vnet.ibm.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

libata depended on SCSI command to have the correct length when
tranlating it into an ATA command.  This generally worked for commands
issued by SCSI HLD but user could issue arbitrary broken command using
sg interface.

Also, when building ATAPI command, full command size was always
copied.  Because some ATAPI devices needs bytes after CDB cleared, if
upper layer doesn't clear bytes after CDB, such devices will
malfunction.  This necessiated recent clear-garbage-after-CDB fix in
sg interfaces.  However, scsi_execute() isn't fixed yet and HL-DT-ST
DVD-RAM GSA-H30N malfunctions on initialization commands issued from
SCSI.

This patch makes xlat functions always consider SCSI cmd_len.  Each
translation function checks for proper cmd_len and ATAPI translaation
clears bytes after CDB.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Cc: Douglas Gilbert <dougg@torque.net>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

xlat function will be updated to consider qc->scsicmd->cmd_len and
many xlat functions deference qc->scsicmd already.  It doesn't make
sense to pass qc->scsicmd->cmnd as @cdb separately.  Kill the
argument.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Variable names in xlat functions are quite confusing now.  'scsicmd'
is used for CDB while qc->scsicmd points to struct scsi_cmnd while
'cmd' is used for struct scsi_cmnd.

This patch cleans up variable names in xlat functions such that 'scmd'
is used for struct scsi_cmnd and 'cdb' for CDB.  Also, 'scmd' local
variable is added if qc->scsicmd is used multiple times.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

We are inside spin_lock_irqsave().  quoth akpm's debug facility:

 [  231.948000] SCSI device sda: 195371568 512-byte hdwr sectors (100030 MB)
 [  232.232000] ata1.00: configured for UDMA/33
 [  232.404000] WARNING (1) at arch/i386/mm/highmem.c:47 kmap_atomic()
 [  232.404000]  [<c01162e6>] kmap_atomic+0xa9/0x1ab
 [  232.404000]  [<c0242c81>] ata_scsi_rbuf_get+0x1c/0x30
 [  232.404000]  [<c0242caf>] ata_scsi_rbuf_fill+0x1a/0x87
 [  232.404000]  [<c0243ab2>] ata_scsiop_mode_sense+0x0/0x309
 [  232.404000]  [<c01729d5>] end_bio_bh_io_sync+0x0/0x37
 [  232.404000]  [<c02311c6>] scsi_done+0x0/0x16
 [  232.404000]  [<c02311c6>] scsi_done+0x0/0x16
 [  232.404000]  [<c0242dcc>] ata_scsi_simulate+0xb0/0x13f
[...]
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Separate out rw ATA taskfile building from ata_scsi_rw_xlat() into
ata_build_rw_tf().  This will be used to improve media error handling.
Signed-off-by: NTejun Heo <htejun@gmail.com>

ata_scsi_dev_rescan() doesn't synchronize against SCSI device detach
and the target sdev might go away in the middle.  Fix it.
Signed-off-by: NTejun Heo <htejun@gmail.com>

* READ CAPACITY (16) implementation fixed.  Result was shifted by two
  bytes.  Carlos Pardo spotted this problem and submitted preliminary
  patch.  Capacity => 2TB is handled correctly now.  (verifid w/ fake
  capacity)

* Use dev->n_sectors instead of re-reading directly from ID data.

* Define and use ATA_SCSI_RBUF_SET() which considers rbuf length.
  This should be done for all simulation functions.  Userland can
  issue any simulated command with arbitrary buffer length.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Cc: Carlos Pardo <Carlos.Pardo@siliconimage.com>

Update ata_gen_ata_sense() to use desc format sense data to report the
first failed block.  The first failed block is read from result_tf
using ata_tf_read_block() which can handle all three address formats.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

* s/ata_gen_ata_desc_sense/ata_gen_passthru_sense/

* s/ata_gen_fixed_sense/ata_gen_ata_sense/

* make both functions static

* neither function has locking requirement, change it to None.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

sb[7] should contain the length of whole information sense data
descriptor while desc[1] should contain the number of following bytes
in the descriptor.  ie. 14 for sb[7] but 12 for desc[1].
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Many drives support LBA48 even when its capacity is smaller than
1<<28, as LBA48 is required for many functionalities.  FLUSH_EXT is
mandatory for drives w/ LBA48 support.

Interestingly, at least one of such drives (ST960812A) has problems
dealing with FLUSH_EXT.  It eventually completes the command but takes
around 7 seconds to finish in many cases thus drastically slowing down
IO transactions.  This seems to be a firmware bug which sneaked into
production probably because no other ATA driver including linux IDE
issues FLUSH_EXT to drives which report support for LBA48 & FLUSH_EXT
but is smaller than 1<<28 blocks.

This patch adds ATA_DFLAG_FLUSH_EXT which is set iff the drive
supports LBA48 & FLUSH_EXT and is larger than LBA28 limit.  Both cache
flush paths are updated to issue FLUSH_EXT only when the flag is set.
Note that the changed behavior is more inline with the rest of libata.
libata prefers shorter commands whenever possible.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Cc: Danny Kukawka <dkukawka@novell.com>
Cc: Stefan Seyfried <seife@novell.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Move dev->max_sectors configuration from ata_scsi_dev_config() to
ata_dev_configure().

* more consistent.
* allows LLDs to peek at the default dev->max_sectors value.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Make user scan wait for scan to complete.  This way user can wait for
warm plug request to complete and is prevented from causing EH event
storm by repetitively issuing scan request while EH is in progress.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Cc: Fajun Chen <fajunchen@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Fixes ata_sas_queuecmd to properly handle a failure from
__ata_scsi_queuecmd.
Signed-off-by: NBrian King <brking@us.ibm.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Do not schedule EH for revalidation on wcache on/off if old EH.  Old
EH cannot handle it and will result in WARN_ON()'s and oops.

This closes bug #7412.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Pass the work_struct pointer to the work function rather than context data.
The work function can use container_of() to work out the data.

For the cases where the container of the work_struct may go away the moment the
pending bit is cleared, it is made possible to defer the release of the
structure by deferring the clearing of the pending bit.

To make this work, an extra flag is introduced into the management side of the
work_struct.  This governs auto-release of the structure upon execution.

Ordinarily, the work queue executor would release the work_struct for further
scheduling or deallocation by clearing the pending bit prior to jumping to the
work function.  This means that, unless the driver makes some guarantee itself
that the work_struct won't go away, the work function may not access anything
else in the work_struct or its container lest they be deallocated..  This is a
problem if the auxiliary data is taken away (as done by the last patch).

However, if the pending bit is *not* cleared before jumping to the work
function, then the work function *may* access the work_struct and its container
with no problems.  But then the work function must itself release the
work_struct by calling work_release().

In most cases, automatic release is fine, so this is the default.  Special
initiators exist for the non-auto-release case (ending in _NAR).
Signed-Off-By: NDavid Howells <dhowells@redhat.com>

A curious thing happens, however, when ata_qc_new_init fails to get
an ata_queued_cmd:

First, ata_qc_new_init handles the failure like this:
    cmd->result = (DID_OK << 16) | (QUEUE_FULL << 1);
    done(cmd);

Then, we return to ata_scsi_translate and do this:
    err_mem:
        cmd->result = (DID_ERROR << 16);
        done(cmd);

It appears to me that first we set a status code indicating that we're
ok but the device queue is full and finish the command,  but then
we blow away that status code and replace it with an error flag and
finish the command a second time!  That does not seem to be desirable
behavior since we merely want the I/O to wait until a command slot
frees up, not send errors up the block layer.

In the err_mem case, we should simply exit out of ata_scsi_translate
instead.
Signed-off-by: NDarrick J. Wong <djwong@us.ibm.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Make the HDIO_DRIVE_CMD ioctl in libata (ATA command pass through) return a
few ATA registers to userspace, following the same convention as the
drivers/ide implementation of the same ioctl.  This is needed to support ATA
commands like CHECK POWER MODE, which return information in nsectors.

This fixes "hdparm -C" on SATA drives.

Forcing the sense data read via the cc flag causes spurious check conditions,
so we filter these out (following the ATA command pass-through specification
T10/04-262r7).
Signed-off-by: NEran Tromer <eran@tromer.org>
Acked-by: NTejun Heo <htejun@gmail.com>
Cc: Jeff Garzik <jeff@garzik.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Turn off NCQ if queue depth is adjusted to 1.
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Update copyright year, fix minor stuff 'make xmldocs' complains about.
Signed-off-by: NJeff Garzik <jeff@garzik.org>

The biggest change is that ata_host_set is renamed to ata_host.

* ata_host_set			=> ata_host
* ata_probe_ent->host_flags	=> ata_probe_ent->port_flags
* ata_probe_ent->host_set_flags	=> ata_probe_ent->_host_flags
* ata_host_stats		=> ata_port_stats
* ata_port->host		=> ata_port->scsi_host
* ata_port->host_set		=> ata_port->host
* ata_port_info->host_flags	=> ata_port_info->flags
* ata_(.*)host_set(.*)\(\)	=> ata_\1host\2()

The leading underscore in ata_probe_ent->_host_flags is to avoid
reusing ->host_flags for different purpose.  Currently, the only user
of the field is libata-bmdma.c and probe_ent itself is scheduled to be
removed.

ata_port->host is reused for different purpose but this field is used
inside libata core proper and of different type.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

SCSI EH locks door if sdev->locked is set.  Sometimes door lock
command fails continuously (e.g. when medium is not present) and as
libata uses EH to acquire sense data, this easily creates a loop where
a failed lock door invokes EH and EH issues lock door on completion.

This patch clears sdev->locked on door lock failure to break this
loop.  This problem has been spotted and diagnosed by Unicorn Chang
<uchang@tw.ibm.com>.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

The following patch enhances libata to allow SAS device drivers
to utilize libata to talk to SATA devices. It introduces some
new APIs which allow libata to be used without allocating a
virtual scsi host.

New APIs:

ata_sas_port_alloc - Allocate an ata_port
ata_sas_port_init - Initialize an ata_port (probe device, etc)
ata_sas_port_destroy - Free an ata_port allocated by ata_sas_port_alloc
ata_sas_slave_configure - configure scsi device
ata_sas_queuecmd - queue a scsi command, similar to ata_scsi_queuecomand

These new APIs can be used either directly by a SAS LLDD or could be used
by the SAS transport class.

Possible usage for a SAS LLDD would be:

scsi_scan_host
	target_alloc
		ata_sas_port_alloc
	slave_alloc
		ata_sas_port_init
	slave_configure
		ata_sas_slave_configure

Commands received by the LLDD for SATA devices would call ata_sas_queuecmd.

Device teardown would occur with:

slave_destroy
	port_disable
target_destroy
	ata_sas_port_destroy
Signed-off-by: NBrian King <brking@us.ibm.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Unify pm_message_t argument to the new-style @mesg.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Reimplement per-dev PM.  The original implementation directly put the
device into suspended mode and didn't synchronize w/ EH operations
including hotplug.  This patch reimplements ata_scsi_device_suspend()
and ata_scsi_device_resume() such that they request EH to perform the
respective operations.  Both functions synchronize with hotplug such
that it doesn't operate on detached devices.

Suspend waits for completion but resume just issues request and
returns.  This allows parallel wake up of devices and thus speeds up
system resume.

Due to sdev detach synchronization, it's not feasible to separate out
EH requesting from sdev handling; thus, ata_device_suspend/resume()
are removed and everything is implemented in the respective
libata-scsi functions.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>