Implement sata_pmp_qc_defer_cmd_switch() - standard qc_defer for
command switching PMP support.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Implement Port Multiplier support.  To support PMP, a LLDD has to
supply ops->pmp_read() and pmp_write().  If non-null, ->pmp_attach and
->pmp_detach are called on PMP attach and detach, respectively.

->pmp_read/write() can be called while the port is frozen, so they
must be implemented by polling.  This patch supplies several helpers
to ease ->pmp_read/write() implementation.

Also, irq_handler and error_handler must be PMP aware.  Most of PMP
aware EH can be done by calling ata_pmp_do_eh() with appropriate
methods.  PMP EH uses separate set of reset methods and this patch
implements standard prereset, hardreset and postreset methods.

This patch only implements PMP support.  The next patch will integrate
PMP into the reset of libata and thus enable PMP support.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Restore the support for handling drives that report one sector too many
(ie SCSI not ATA style). This worked before the HPA update but was
removed in that process.
Signed-off-by: NAlan Cox <alan@redhat.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

AN serves multiple purposes.  For ATAPI, it's used for media change
notification.  For PMP, for downstream PHY status change notification.
Implement sata_async_notification() which demultiplexes AN.

To avoid unnecessary port events, ATAPI AN is not enabled if PMP is
attached but SNTF is not available.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Cc: Kriten Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Some pseudo devices fail PM commands unnecessarily aborting system
suspend.  Implement ATA_HORKAGE_SKIP_PM which makes libata skip PM
commands for these devices.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Implement ATA_LFLAG_DISABLED.  The flag indicates the link is disabled
due to EH recovery failure.  While a link is disabled, no EH action is
taken on the link and suspend/resume become noop too.

This will be used by PMP links to manage failed links.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Some PMP links are connected to internal pseudo devices which may come
and go depending on situation.  There's no reason to try hard to
recover them.  ATA_LFLAG_NO_RETRY tells EH to not retry if the device
attached to the link fails.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Some links on some PMPs locks up on SRST and/or report incorrect
device signature.  Implement ATA_LFLAG_NO_SRST, ASSUME_ATA and
ASSUME_SEMB to handle these quirky links.  NO_SRST makes EH avoid
SRST.  ASSUME_ATA and SEMB forces class code to ATA and SEMB_UNSUP
respectively.  Note that SEMB isn't currently supported yet so the
_UNSUP variant is used.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Implement ap->nr_active_links (the number of links with active qcs),
ap->excl_link (pointer to link which can be used by ->qc_defer and is
cleared when a qc with ATA_QCFLAG_CLEAR_EXCL completes), and
ata_link_active().

These can be used by ->qc_defer() to implement proper command
exclusion.  This set of helpers seem enough for both sil24 (ATAPI
exclusion needed) and cmd-switching PMP.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Controllers which support PMP have various restrictions on which
combinations of commands are allowed to what number of devices
concurrently.  This patch implements ops->qc_defer() which determines
whether a qc can be issued at the moment or should be deferred.

If the function returns ATA_DEFER_LINK, the qc will be deferred until
a qc completes on the link.  If ATA_DEFER_PORT, until a qc completes
on any link.  The defer conditions are advisory and in general
ATA_DEFER_LINK can be considered as lower priority deferring than
ATA_DEFER_PORT.

ops->qc_defer() replaces fixed ata_scmd_need_defer().  For standard
NCQ/non-NCQ exclusion, ata_std_qc_defer() is implemented.  ahci and
sata_sil24 are converted to use ata_std_qc_defer().

ops->qc_defer() is heavier than the original mechanism because full qc
is prepped before determining to defer it, but various information is
needed to determine defer conditinos and fully translating a qc is the
only way to supply such information in generic manner.

IMHO, this shouldn't cause any noticeable performance issues as

* for most cases deferring occurs rarely (except for NCQ-aware
  cmd-switching PMP)
* translation itself isn't that expensive
* once deferred the command won't be repeated until another command
  completes which usually is a very long time cpu-wise.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Add PMP related constants, fields and ops.  Also, update
ata_class_enabled/disabled() such that PMP classes are considered.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Make ata_dev_try_classify() take a pointer to ata_device instead of
ata_port/port_number combination for consistency and add @present
argument.  @present indicates whether the device seems present during
reset.  It's the result of TF access during softreset and link
onlineness during hardreset.  @present will be used to improve
diagnostic failure handling.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

In anticipation of more features, increase number of config flags
allowed, and move the init flags.
Signed-off-by: NKristen Carlson Accardi <kristen.c.accardi@intel.com>
Cc: Hugh Dickens <hugh@veritas.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

EH is sometimes repeated without any error or action.  For example,
this happens when probing IDENTIFY fails because of a phantom device.
In these cases, all the repeated EH does is making sure there is no
unhandled error or pending action and return.  This repeation is
necessary to avoid losing any event which occurred while EH was in
progress.

Unfortunately, this dry run causes annonying "EH pending after
completion" message.  This patch moves the repeat reporting into
ata_eh_report() such that it's more compact and skipped on dry runs.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Cc: Mikael Pettersson <mikep@it.uu.se>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Currently, port configuration reporting has the following problems.

* iomapped address is reported instead of raw address
* report contains irrelevant fields or lacks necessary fields for
  non-SFF controllers.
* host->irq/irq2 are there just for reporting and hacky.

This patch implements and uses ata_port_desc() and
ata_port_pbar_desc().  ata_port_desc() is almost identical to
ata_ehi_push_desc() except that it takes @ap instead of @ehi, has no
locking requirement, can only be used during host initialization and "
" is used as separator instead of ", ".  ata_port_pbar_desc() is a
helper to ease reporting of a PCI BAR or an offsetted address into it.

LLD pushes whatever description it wants using the above two
functions.  The accumulated description is printed on host
registration after "[S/P]ATA max MAX_XFERMODE ".

SFF init helpers and ata_host_activate() automatically add
descriptions for addresses and irq respectively, so only LLDs which
isn't standard SFF need to add custom descriptions.  In many cases,
such controllers need to report different things anyway.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

It was always set to ata_port_disable().  Removed the hook, and replaced
the very few ap->ops->port_disable() callsites with direct calls to
ata_port_disable().
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Combined from two Alan Cox patches:

1) libata: ACPI checks for 80wire cable

We can use the ACPI mode information with several drivers as a hint to
cable type. If the ACPI mode set by the BIOS is faster than UDMA33 then
we know the BIOS thinks there are 80wire cables. If it doesn't set such a
mode or it has no ACPI method then we get no further information and can
rely on existing approaches

Introduce the function headers needed. Null it out for non ACPI boxes
Signed-off-by: NAlan Cox <alan@redhat.com>

2) libata: ACPI checks for 80wire cable

Provide actual methods for checking if the ACPI support thinks the cable
is 80wire, or doesn't know
Signed-off-by: NAlan Cox <alan@redhat.com>

Combined into a single changeset and
Signed-off-by: NJeff Garzik <jeff@garzik.org>

* ->irq_ack() is redundant to what the irq handler already
  performs... chk-status + irq-clear.  Furthermore, it is only
  called in one place, when screaming-irq-debugging is enabled,
  so we don't want to bother with a hook just for that.

* ata_dummy_irq_on() is only ever used in drivers that have
  no callpath reaching ->irq_on().  Remove .irq_on hook from
  those drivers, and the now-unused ata_dummy_irq_on()
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Tell the compiler that [__]ata_ehi_push_desc() functions take printf
style format string and arguments.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

ata_wait_idle() identified controller by printing out the address of
the Status register.  This is bogus because 1. it's iomapped address
2. some controllers don't have Status register and don't initialize
the field.  Use ata_port_printk() instead.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

When we get an SDB FIS with the 'N' bit set, we should send
an event to user space to indicate that there has been a
media change.  This will be done via the scsi device.
Signed-off-by: NKristen Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Check to see if an ATAPI device supports Asynchronous Notification.
If so, enable it, if the host controller supports AN.
Signed-off-by: NKristen Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Add link->pmp, ap->nr_pmp_links, ap->pmp_link[], and implement/update
link helpers.

printk helpers are updated such that port and link are identifed as
'ataP:' if no PMP is attached, while device is identified as
'ataP.DD:'.  If PMP is attached, they become 'ataP:', 'ataP.LL:' and
'ataP.LL' - ie. link and device are identified their PMP number.

If PPM is attached (ap->nr_pmp_links != 0), ata_for_each_link()
iterates over PMP links, while __ata_for_each_link() iterates over the
host link + PMP links.  If PMP is not attached (ap->nr_pmp_links ==
0), both iterate over only the host link.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Implement ata_link_abort().
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

HRST_TO_RESUME and SKIP_D2H_BSY are link attributes.  Move them to
ata_link->flags.  This will allow host and PMP links to have different
attributes.  ata_port_info->link_flags is added and used by LLDs to
specify these flags during initialization.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Make the following functions deal with ata_link instead of ata_port.

* ata_set_mode()
* ata_eh_autopsy() and related functions
* ata_eh_report() and related functions
* suspend/resume related functions
* ata_eh_recover() and related functions
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Make reset methods and related functions deal with ata_link instead of
ata_port.

* ata_do_reset()
* ata_eh_reset()
* all prereset/reset/postreset methods and related functions

This patch introduces no behavior change.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Make the following PHY-related functions to deal with ata_link instead
of ata_port.

* sata_print_link_status()
* sata_down_spd_limit()
* ata_set_sata_spd_limit() and friends
* sata_link_debounce/resume()
* sata_scr_valid/read/write/write_flush()
* ata_link_on/offline()

This patch introduces no behavior change.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Multiple links and different number of devices per link should be
considered to iterate over links and devices.  This patch implements
and uses link and device iterators - ata_port_for_each_link() and
ata_link_for_each_dev() - and ata_link_max_devices().

This change makes a lot of functions iterate over only possible
devices instead of from dev 0 to dev ATA_MAX_DEVICES.  All such
changes have been examined and nothing should be broken.

While at it, add a separating comment before device helpers to
distinguish them better from link helpers and others.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Introduce ata_link.  It abstracts PHY and sits between ata_port and
ata_device.  This new level of abstraction is necessary to support
SATA Port Multiplier, which basically adds a bunch of links (PHYs) to
a ATA host port.  Fields related to command execution, spd_limit and
EH are per-link and thus moved to ata_link.

This patch only defines the host link.  Multiple link handling will be
added later.  Also, a lot of ap->link derefences are added but many of
them will be removed as each part is converted to deal directly with
ata_link instead of ata_port.

This patch introduces no behavior change.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Cc: James Bottomley <James.Bottomley@SteelEye.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Some drives choke on READ_NATIVE_MAX_ADDRESS[_EXT].  Implement
ATA_HORKAGE_BROKEN_HPA and apply it to affected drives.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

ACPI implementations in several TOSHIBA laptops are weird and burn cpu
cycles for tens of seconds while trying to suspend if the PCI device
for the ATA controller is disabled when the ACPI suspend is called.

This patch uses DMI to match those machines and bypass device disable
on those machines during suspend.  As the device needs to be put into
enabled state on resume without affecting PCI enable count, matching
resume callback uses __pci_reenable_device().

This bug is reported in bugzilla bug 7780.

  http://bugzilla.kernel.org/show_bug.cgi?id=7780Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

In most cases, when EH is scheduled, all in-flight commands are
aborted causing EH to kick in immediately.  However, in some cases
(especially with PMP), it's unclear which commands are affected by the
error condition and although aborting all in-flight commands work, it
isn't optimal and may cause unnecessary disruption.  On the other
hand, waiting for in-flight commands to drain themselves can take up
to 30seconds.

This patch implements EH fast drain to handle such situations.  It
gives in-flight commands some time to finish up but doesn't wait for
too long.  After EH is scheduled, fast drain timer is started and if
no other completion occurs in ATA_EH_FASTDRAIN_INTERVAL all in-flight
commands are aborted.  If any completion occurred in the interval, the
port is given another interval to finish up itself.

Currently ATA_EH_FASTDRAIN_INTERVAL is 3 secs which should be enough
for finishing up most commands.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

__ata_ehi_hotplugged() now has no users.  Regorganize
ata_ehi_hotplugged() such that a new function ata_ehi_schedule_probe()
deals with scheduling probing.  ata_ehi_hotplugged() calls it and
additionally marks hotplug specific flags.  ata_ehi_schedule_probe()
will be used laster.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

sata_down_spd_limit() first reads the current SPD from SStatus and
limit the speed to the lower one of one below the current limit or one
below the current SPD in SStatus.  SPD may not be accessible or valid
when SPD down is requested making sata_down_spd_limit() fail when it's
most needed.

This patch makes the current SPD cached after each successful reset
and forces GEN I speed (1.5Gbps) if neither of SStatus or the cached
value is valid, so sata_down_spd_limit() is now guaranteed to lower
the speed limit if lower speed is available.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Convert ->scr_read/write callbacks to return error code to better
indicate failure.  This will help handling of SCR_NOTIFICATION.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

When an NCQ command fails, all commands in flight are aborted and the
offending one is reported using log page 10h.  Depending on controller
characteristics and LLD implementation, all commands may appear as
having a device error due to shared TF status making it hard to
determine what's actually going on.

This patch adds AC_ERR_NCQ, marks the command reported by log page 10h
with it and print extra "<F>" after the error report for the command
to help distinguishing the offending command.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Requiring LLDs to format multiple error description messages properly
doesn't work too well.  Help LLDs a bit by making ata_ehi_push_desc()
insert ", " on each invocation.  __ata_ehi_push_desc() is the raw
version without the automatic separator.

While at it, make ehi_desc interface proper functions instead of
macros.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Add @is_cmd to ata_tf_to_fis().  This controls bit 7 of the second
byte which tells the device whether this H2D FIS is for a command or
not.  This cleans up ahci a bit and will be used by PMP.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

This patch adds a new field, lldd_task, to ata_queued_cmd so that libata
users such as libsas can associate some data with a qc.  The particular
ambition with this patch is to associate a sas_task with a qc; that way,
if libata decides to timeout a command, we can come back (in
sas_ata_post_internal) and abort the sas task.

One question remains: Is it necessary to reset the phy on error, or will
the libata error handler take care of it?  (Assuming that one is written,
of course.)  This patch, as it is today, works well enough to clean
things up when an ATA device probe attempt fails halfway through the probe,
though I'm not sure this is always the right thing to do.
Signed-off-by: NDarrick J. Wong <djwong@us.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>