As suggested by Linus: Don't do the libata init in 2 separate
steps with a global sync inbetween, but do it as one async step,
with a local sync before registering the device.

This cuts the boottime on my machine with 2 sata controllers down
significantly, and it seems to work. Would be nice if the libata
folks take a good look at this patch though..
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>

This patch makes the libata port scanning asynchronous (per device).
There is a synchronization point before doing the actual disk scan
so that device ordering is not affected.
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>

The patchlet below blacklists NCQ on OCZ CORE v2 SSD drive(s). Even
though the drive advertises NCQ support with queue depth 1, it responds
with all-zeroes FIS to NCQ commands which triggers ata error handling
several times before the kernel decides to disable NCQ on the drive.
Signed-off-by: NLubomir Bulej <lubomir.bulej@dsrg.mff.cuni.cz>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

Signed-off-by: NQinghuang Feng <qhfeng.kernel@gmail.com>

ata_port_detach() first made sure EH saw ATA_PFLAG_UNLOADING and then
assumed EH context belongs to it and performed detach operation
itself.  However, UNLOADING doesn't disable all of EH and this could
lead to problems including triggering WARN_ON()'s in EH path.

This patch makes port detach behave more like other EH actions such
that ata_port_detach() requests EH to detach and waits for completion.
Signed-off-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

When restoring SControl during detach, PMP links should be handled
first as changing SControl of the host link can affect SCR access of
PMP links.
Signed-off-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

There currently are the following looping constructs.

* __ata_port_for_each_link() for all available links
* ata_port_for_each_link() for edge links
* ata_link_for_each_dev() for all devices
* ata_link_for_each_dev_reverse() for all devices in reverse order

Now there's a need for looping construct which is similar to
__ata_port_for_each_link() but iterates over PMP links before the host
link.  Instead of adding another one with long name, do the following
cleanup.

* Implement and export ata_link_next() and ata_dev_next() which take
  @mode parameter and can be used to build custom loop.
* Implement ata_for_each_link() and ata_for_each_dev() which take
  looping mode explicitly.

The following iteration modes are implemented.

* ATA_LITER_EDGE		: loop over edge links
* ATA_LITER_HOST_FIRST		: loop over all links, host link first
* ATA_LITER_PMP_FIRST		: loop over all links, PMP links first

* ATA_DITER_ENABLED		: loop over enabled devices
* ATA_DITER_ENABLED_REVERSE	: loop over enabled devices in reverse order
* ATA_DITER_ALL			: loop over all devices
* ATA_DITER_ALL_REVERSE		: loop over all devices in reverse order

This change removes exlicit device enabledness checks from many loops
and makes it clear which ones are iterated over in which direction.
Signed-off-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

Due to miscommunication, P/N was mistaken as firmware revision
strings.  Update it.
Signed-off-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

Some recent Seagate harddrives have firmware bug which causes FLUSH
CACHE to timeout under certain circumstances if NCQ is being used.
This can be worked around by disabling NCQ and fixed by updating the
firmware.  Implement ATA_HORKAGE_FIRMWARE_UPDATE and blacklist these
devices.

The wiki page has been updated to contain information on this issue.

  http://ata.wiki.kernel.org/index.php/Known_issuesSigned-off-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

Phillip O'Donnell <phillip.odonnell@gmail.com> pointed out that the same
sign extension bug that was fixed in commit ba14a9c2 ("libata: Avoid
overflow in ata_tf_to_lba48() when tf->hba_lbal > 127") also appears to
exist in ata_tf_read_block().  Fix this by adding a cast to u64.
Signed-off-by: NRoland Dreier <rolandd@cisco.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

This patch reverts the following three commits which convert libata to
use block layer tagging.

 43a49cbd
 e013e13b
 2fca5ccf

Although using block layer tagging is the right direction, due to the
tight coupling among tag number, data structure allocation and
hardware command slot allocation, libata doesn't work correctly with
the current conversion.

The biggest problem is guaranteeing that tag 0 is always used for
non-NCQ commands.  Due to the way blk-tag is implemented and how SCSI
starts and finishes requests, such guarantee can't be made.  I'm not
sure whether this would actually break any low level driver but it
doesn't look like a good idea to break such assumption given the
frailty of ATA controllers.

So, for the time being, keep using the old dumb in-libata qc
allocation.
Signed-off-by: NTejun Heo <tj@kernel.org>
Cc: Jens Axobe <jens.axboe@oracle.com>
Cc: Jeff Garzik <jeff@garzik.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

libata restores SControl on detach; however, trying to restore
non-zero DET can cause undeterministic behavior including PMP device
going offline till power cycling.  Mask off DET when restoring
SControl.
Signed-off-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

libata always uses PIO for ATAPI commands when the number of bytes to
transfer isn't multiple of 16 but quantum DAT72 chokes on odd bytes
PIO transfers.  Implement a horkage to skip the mod16 check and apply
it to the quantum device.

This is reported by John Clark in the following thread.

  http://thread.gmane.org/gmane.linux.ide/34748Signed-off-by: NTejun Heo <tj@kernel.org>
Cc: John Clark <clarkjc@runbox.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

libata currently imposes a UDMA5 max transfer rate and 200 sector max
transfer size for SATA devices that sit behind a pata-sata bridge. Lots
of devices have known good bridges that don't need this limit applied.
The MTRON SSD disks are such devices. Transfer rates are increased by
20-30% with the restriction removed.

So add a "blacklist" entry for the MTRON devices, with a flag indicating
that the bridge is known good.
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

In ata_tf_to_lba48(), when evaluating

	(tf->hob_lbal & 0xff) << 24

the expression is promoted to signed int (since int can hold all values
of u8).  However, if hob_lbal is 128 or more, then it is treated as a
negative signed value and sign-extended when promoted to u64 to | into
sectors, which leads to the MSB 32 bits of section getting set
incorrectly.

For example, Phillip O'Donnell <phillip.odonnell@gmail.com> reported
that a 1.5GB drive caused:

    ata3.00: HPA detected: current 2930277168, native 18446744072344861488

where 2930277168 == 0xAEA87B30 and 18446744072344861488 == 0xffffffffaea87b30
which shows the problem when hob_lbal is 0xae.

Fix this by adding a cast to u64, just as is used by for hob_lbah and
hob_lbam in the function.
Reported-by: NPhillip O'Donnell <phillip.odonnell@gmail.com>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

Remove excess kernel-doc function parameter notation from drivers/ata/:

Warning(drivers/ata/libata-core.c:1622): Excess function parameter or struct member 'fn' description in 'ata_pio_queue_task'
Warning(drivers/ata/libata-core.c:4655): Excess function parameter or struct member 'err_mask' description in 'ata_qc_complete'
Warning(drivers/ata/ata_piix.c:751): Excess function parameter or struct member 'udma' description in 'do_pata_set_dmamode'
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

Fix libata missing kernel-doc:

Warning(lin2628-rc2//drivers/ata/libata-core.c:4562): No description
found for parameter 'tag'
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

There were several places where only enabled devices should be
iterated over but device enabledness wasn't checked.

* IDENTIFY data 40 wire check in cable_is_40wire()
* xfer_mode/ncq_enabled saving in ata_scsi_error()
* DUBIOUS_XFER handling in ata_set_mode()

While at it, reformat comments in cable_is_40wire().
Signed-off-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

libata currently has a pretty dumb ATA_MAX_QUEUE loop for finding
a free tag to use. Instead of fixing that up, convert libata to
using block layer tagging - gets rid of code in libata, and is also
much faster.
Signed-off-by: NJens Axboe <jens.axboe@oracle.com>
Acked-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

ap->port_task was not initialized if !CONFIG_ATA_SFF later triggering
lockdep warning.  Make sure it's initialized.

Reported by Larry Finger.
Signed-off-by: NTejun Heo <tj@kernel.org>
Cc: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

On user request (through sysfs), the IDLE IMMEDIATE command with UNLOAD
FEATURE as specified in ATA-7 is issued to the device and processing of
the request queue is stopped thereafter until the specified timeout
expires or user space asks to resume normal operation. This is supposed
to prevent the heads of a hard drive from accidentally crashing onto the
platter when a heavy shock is anticipated (like a falling laptop
expected to hit the floor). In fact, the whole port stops processing
commands until the timeout has expired in order to avoid any resets due
to failed commands on another device.
Signed-off-by: NElias Oltmanns <eo@nebensachen.de>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

Explanation taken from the comment of ata_slave_link_init().

 In libata, a port contains links and a link contains devices.  There
 is single host link but if a PMP is attached to it, there can be
 multiple fan-out links.  On SATA, there's usually a single device
 connected to a link but PATA and SATA controllers emulating TF based
 interface can have two - master and slave.

 However, there are a few controllers which don't fit into this
 abstraction too well - SATA controllers which emulate TF interface
 with both master and slave devices but also have separate SCR
 register sets for each device.  These controllers need separate links
 for physical link handling (e.g. onlineness, link speed) but should
 be treated like a traditional M/S controller for everything else
 (e.g. command issue, softreset).

 slave_link is libata's way of handling this class of controllers
 without impacting core layer too much.  For anything other than
 physical link handling, the default host link is used for both master
 and slave.  For physical link handling, separate @ap->slave_link is
 used.  All dirty details are implemented inside libata core layer.
 From LLD's POV, the only difference is that prereset, hardreset and
 postreset are called once more for the slave link, so the reset
 sequence looks like the following.

 prereset(M) -> prereset(S) -> hardreset(M) -> hardreset(S) ->
 softreset(M) -> postreset(M) -> postreset(S)

 Note that softreset is called only for the master.  Softreset resets
 both M/S by definition, so SRST on master should handle both (the
 standard method will work just fine).

As slave_link excludes PMP support and only code paths which deal with
the attributes of physical link are affected, all the changes are
localized to libata.h, libata-core.c and libata-eh.c.

 * ata_is_host_link() updated so that slave_link is considered as host
   link too.

 * iterator extended to iterate over the slave_link when using the
   underbarred version.

 * force param handling updated such that devno 16 is mapped to the
   slave link/device.

 * ata_link_on/offline() updated to return the combined result from
   master and slave link.  ata_phys_link_on/offline() are the direct
   versions.

 * EH autopsy and report are performed separately for master slave
   links.  Reset is udpated to implement the above described reset
   sequence.

Except for reset update, most changes are minor, many of them just
modifying dev->link to ata_dev_phys_link(dev) or using phys online
test instead.

After this update, LLDs can take full advantage of per-dev SCR
registers by simply turning on slave link.
Signed-off-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

* Add ATA_EH_ALL_ACTIONS.

* Make sata_link_{on|off}_line() return bool instead of int.
Signed-off-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

Implement __ata_port_next_link() and reimplement
__ata_port_for_each_link() and ata_port_for_each_link() using it.
This removes relatively large inlined code and makes iteration easier
to extend.
Signed-off-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

Logically, SCR access ops should take @link; however, there was no
compelling reason to convert all SCR access ops when adding @link
abstraction as there's one-to-one mapping between a port and a non-PMP
link.  However, that assumption won't hold anymore with the scheduled
addition of slave link.

Make SCR access ops per-link.
Signed-off-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

Dave Müller sent a diff for the pata_oldpiix that highlighted a problem
where a lot of the ATA drivers assume dma_mode == 0 means "no DMA" while
the core code uses 0xFF.

This turns out to have other consequences such as code doing >= XFER_UDMA_0
also catching 0xFF as UDMAlots. Fortunately it doesn't generally affect
set_dma_mode, although some drivers call back into their own set mode code
from other points.

Having been through the drivers I've added helpers for using_udma/using_mwdma
dma_enabled so that people don't open code ranges that may change (eg if UDMA8
appears somewhere)

Thanks to David for the initial bits
[and added fix for pata_oldpiix from and signed-off-by Dave Mueller
 <dave.mueller@gmx.ch>  -jg]
Signed-off-by: NAlan Cox <alan@redhat.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

Save SControl during probing and restore it on detach.  This prevents
adjustments made by libata drivers to seep into the next driver which
gets attached (be it a libata one or not).

It's not clear whether SControl also needs to be restored on suspend.
The next system to have control (ACPI or kexec'd kernel) would
probably like to see the original SControl value but there's no
guarantee that a link is gonna keep working after SControl is adjusted
without a reset and adding a reset and modified recovery cycle soley
for this is an overkill.  For now, do it only for detach.
Signed-off-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

Implement force params nohrst, nosrst and norst.  This is to work
around reset related problems and ease debugging.
Signed-off-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

- Add support for the RDC 1010 variant
- Rework the core library to have a read_id method. This allows the hacky
  bits of it821x to go and prepares us for pata_hd
- Switch from WARN to BUG in ata_id_string as it will reboot if you get
  it wrong so WARN won't be seen
- Allow the issue of command 0xFC on the 821x. This is needed to query
  rebuild status.
- Tidy up printk formatting
- Do more ident rewriting on RAID volumes to handle firmware provided
  ident data which is rather wonky
- Report the firmware revision and device layout in RAID mode
- Don't try and disable raid on the 8211 or RDC - they don't have the
  relevant bits
Signed-off-by: NAlan Cox <alan@redhat.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

Fix a potential memory leak when ata_init() encounters an error.
Signed-off-by: NElias Oltmanns <eo@nebensachen.de>
Cc: Tejun Heo <tj@kernel.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

Global and per-LLD ATAPI disable checks were done in the command issue
path probably because it was left out during EH conversion.  On
affected machines, this can cause lots of warning messages.  Move them
to where they belong - the probing path.

Reported by Chunbo Luo.
Signed-off-by: NTejun Heo <tj@kernel.org>
Cc: Chunbo Luo <chunbo.luo@windriver.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

ATA_TMOUT_INTERNAL which was 30secs were used for all internal
commands which is way too long when something goes wrong.  This patch
implements command type based stepped timeouts.  Different command
types can use different timeouts and each command type can use
different timeout values after timeouts.

ie. the initial timeout is set to a value which should cover most of
the cases but not too long so that run away cases don't delay things
too much.  After the first try times out, the second try can use
longer timeout and if that one times out too, it can go for full 30sec
timeout.

IDENTIFYs use 5s - 10s - 30s timeout and all other commands use 5s -
10s timeouts.

This patch significantly cuts down the needed time to handle failure
cases while still allowing libata to work with nut job devices through
retries.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

libata has been using mix of jiffies and msecs for time druations.
This is getting confusing.  As writing sub HZ values in jiffies is
PITA and msecs_to_jiffies() can't be used as initializer, unify unit
for all time durations to msecs.  So, durations are in msecs and
deadlines are in jiffies.  ata_deadline() is added to compute deadline
from a start time and duration in msecs.

While at it, drop now superflous _msec suffix from arguments and
rename @timeout to @deadline if it represents a fixed point in time
rather than duration.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

There's no reason to check whether to use DMA or not for no data
commands.  Don't do it.  While at it, make local variable using_pio in
atapi_xlat() set iff ATAPI_PROT_PIO is going to be used and rename
ata_check_atapi_dma() to atapi_check_dma() for consistency.
Signed-off-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

Replace deprecated static spinlock_t instance to static DEFINE_SPINLOCK(lock).
Signed-off-by: NPradeep Singh <rautelap@gmail.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

I was hoping ATA_HORKAGE_NODMA | ATA_HORKAGE_SKIP_PM could keep it
happy but no even this doesn't work under certain configurations and
it's not like we can do anything useful with the cofig device anyway.
Replace ATA_HORKAGE_SKIP_PM with ATA_HORKAGE_DISABLE and use it for
the config device.  This makes the device completely ignored by
libata.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

There's no reason to schedule LPM action after probing is complete
causing another EH iteration.  Just schedule it together with probing
itself.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

Originally, whole reset processing was done while the port is frozen
and SError was cleared during @postreset().  This had two race
conditions.  1: hotplug could occur after reset but before SError is
cleared and libata won't know about it.  2: hotplug could occur after
all the reset is complete but before the port is thawed.  As all
events are cleared on thaw, the hotplug event would be lost.

Commit ac371987 kills the first race
by clearing SError during link resume but before link onlineness test.
However, this doesn't fix race #2 and in some cases clearing SError
after SRST is a good idea.

This patch solves this problem by cross checking link onlineness with
classification result after SError is cleared and port is thawed.
Reset is retried if link is online but all devices attached to the
link are unknown.  As all devices will be revalidated, this one-way
check is enough to ensure that all devices are detected and
revalidated reliably.

This, luckily, also fixes the cases where host controller returns
bogus status while harddrive is spinning up after hotplug making
classification run before the device sends the first FIS and thus
causes misdetection.

Low level drivers can bypass the logic by setting class explicitly to
ATA_DEV_NONE if ever necessary (currently none requires this).
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

The @online out parameter is supposed to set to true iff link is
online and reset succeeded as advertised in the function description
and callers are coded expecting that.  However, sata_link_reset()
didn't behave this way on device readiness test failure.  Fix it.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

Export ata_eh_analyze_ncq_error() for subsequent use by sata_mv,
as suggested by Tejun.
Signed-off-by: NMark Lord <mlord@pobox.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>