ATA_EHI_RESUME_LINK has two functions - promote reset to hardreset if
ATA_LFLAG_HRST_TO_RESUME is set and preventing EH from shortcutting
reset action when probing is requested.  The former is gone now and
the latter can easily be achieved by making EH to perform at least one
reset if reset is requested, which also makes more sense than
depending on RESUME_LINK flag.

As ATA_EHI_RESUME_LINK was the only EHI reset modifier, this also
kills reset modifier handling.
Signed-off-by: NTejun Heo <htejun@gmail.com>

Now that hardreset is the preferred method of resetting, there's no
need for ATA_LFLAG_HRST_TO_RESUME flag.  Kill it.
Signed-off-by: NTejun Heo <htejun@gmail.com>

When both soft and hard resets are available, libata preferred
softreset till now.  The logic behind it was to be softer to devices;
however, this doesn't really help much.  Rationales for the change:

* BIOS may freeze lock certain things during boot and softreset can't
  unlock those.  This by itself is okay but during operation PHY event
  or other error conditions can trigger hardreset and the device may
  end up with different configuration.

  For example, after a hardreset, previously unlockable HPA can be
  unlocked resulting in different device size and thus revalidation
  failure.  Similar condition can occur during or after resume.

* Certain ATAPI devices require hardreset to recover after certain
  error conditions.  On PATA, this is done by issuing the DEVICE RESET
  command.  On SATA, COMRESET has equivalent effect.  The problem is
  that DEVICE RESET needs its own execution protocol.

  For SFF controllers with bare TF access, it can be easily
  implemented but more advanced controllers (e.g. ahci and sata_sil24)
  require specialized implementations.  Simply using hardreset solves
  the problem nicely.

* COMRESET initialization sequence is the norm in SATA land and many
  SATA devices don't work properly if only SRST is used.  For example,
  some PMPs behave this way and libata works around by always issuing
  hardreset if the host supports PMP.

  Like the above example, libata has developed a number of mechanisms
  aiming to promote softreset to hardreset if softreset is not going
  to work.  This approach is time consuming and error prone.

  Also, note that, dependingon how you read the specs, it could be
  argued that PMP fan-out ports require COMRESET to start operation.
  In fact, all the PMPs on the market except one don't work properly
  if COMRESET is not issued to fan-out ports after PMP reset.

* COMRESET is an integral part of SATA connection and any working
  device should be able to handle COMRESET properly.  After all, it's
  the way to signal hardreset during reboot.  This is the most used
  and recommended (at least by the ahci spec) method of resetting
  devices.

So, this patch makes libata prefer hardreset over softreset by making
the following changes.

* Rename ATA_EH_RESET_MASK to ATA_EH_RESET and use it whereever
  ATA_EH_{SOFT|HARD}RESET used to be used.  ATA_EH_{SOFT|HARD}RESET is
  now only used to tell prereset whether soft or hard reset will be
  issued.

* Strip out now unneeded promote-to-hardreset logics from
  ata_eh_reset(), ata_std_prereset(), sata_pmp_std_prereset() and
  other places.
Signed-off-by: NTejun Heo <htejun@gmail.com>

SAT passthrus don't really fit into ATAPI_MISC class.  SAT passthru
commands always transfer multiple of 512 bytes and variable length
response is not allowed.  This patch creates a separate category -
ATAPI_PASS_THRU - for these.

This fixes HSM violation on "hdparm -I".
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Uninline atapi_cmd_type().  It doesn't really have to be inline and
more case will be added which need to access unexported libata
variable.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

EH actions are ATA_EH_* not ATA_EHI_*.  Rename ATA_EHI_LPM to
ATA_EH_LPM.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Cc: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Implement ata_qc_raw_nbytes() which determines the raw user-requested
size of a PC command.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Back in 2.6.17-rc2, a libata module parameter was added for atapi_dmadir.

That's nice, but most SATA devices which need it will tell us about it
in their IDENTIFY PACKET response, as bit-15 of word-62 of the
returned data (as per ATA7, ATA8 specifications).

So for those which specify it, we should automatically use the DMADIR bit.
Otherwise, disc writing will fail by default on many SATA-ATAPI drives.

This patch adds ATA_DFLAG_DMADIR and make ata_dev_configure() set it
if atapi_dmadir is set or identify data indicates DMADIR is necessary.
atapi_xlat() is converted to check ATA_DFLAG_DMADIR before setting
DMADIR.

Original patch is from Mark Lord.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Cc: Mark Lord <mlord@pobox.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Avoids lots of these, also is more readable.
include/linux/libata.h:1210:13: warning: potentially expensive pointer subtraction

Change the subtraction to addition on the other side of the comparison.

Thanks to Christer Weinigel for the suggestion.
Signed-off-by: NHarvey Harrison <harvey.harrison@gmail.com>
Acked-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

that provided by the block layer

ATA requires that all DMA transfers begin and end on word boundaries.
Because of this, a large amount of machinery grew up in ide to adjust
scatterlists on this basis.  However, as of 2.5, the block layer has a
dma_alignment variable which ensures both the beginning and length of a
DMA transfer are aligned on the dma_alignment boundary.  Although the
block layer does adjust the beginning of the transfer to ensure this
happens, it doesn't actually adjust the length, it merely makes sure
that space is allocated for transfers beyond the declared length.  The
upshot of this is that scatterlists may be padded to any size between
the actual length and the length adjusted to the dma_alignment safely
knowing that memory is allocated in this region.

Right at the moment, SCSI takes the default dma_aligment which is on a
512 byte boundary.  Note that this aligment only applies to transfers
coming in from user space.  However, since all kernel allocations are
automatically aligned on a minimum of 32 byte boundaries, it is safe to
adjust them in this manner as well.

tj: * Adjusting sg after padding is done in block layer.  Make libata
      set queue alignment correctly for ATAPI devices and drop broken
      sg mangling from ata_sg_setup().
    * Use request->raw_data_len for ATAPI transfer chunk size.
    * Killed qc->raw_nbytes.
    * Separated out killing qc->n_iter.
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJens Axboe <jens.axboe@oracle.com>

qc->n_iter was used for libata's own sg walking before sg chaining
replaced it.  During conversion, the field and its usage in sata_fsl
were left behind.  Kill the filed and update sata_fsl.

tj: This was part of James's libata-use-block-layer-padding patch.
    Separated out by me.
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: NTejun Heo <htejun@gmail.com>
Cc: Li Yang <leoli@freescale.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Factor out ata_pci_activate_sff_host() from ata_pci_one().  This does
about the same thing as ata_host_activate() but needs to be separate
because SFF controllers use different and multiple IRQs in legacy
mode.

This will be used to make SFF LLD initialization more flexible.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

ata_port_queue_task() served a single user:  ata_pio_task()

Rename to ata_pio_queue_task() and un-export it, as nobody outside of
libata-core.c uses it.
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

qc->nbytes didn't use to include extra buffers setup by libata core
layer and my be odd.  This patch makes qc->nbytes include any extra
buffers setup by libata core layer and guaranteed to be aligned on 4
byte boundary.

This value is to be used to program the host controller.  As this
represents the actual length of buffer available to the controller and
the controller must be able to deal with short transfers for ATAPI
commands which can transfer variable length, this shouldn't break any
controllers while making problems like rounding-down and controllers
choking up on odd transfer bytes much less likely.

The unmodified value is stored in new field qc->raw_nbytes.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

libata used private sg iterator to handle padding sg.  Now that sg can
be chained, padding can be handled using standard sg ops.  Convert to
chained sg.

* s/qc->__sg/qc->sg/

* s/qc->pad_sgent/qc->extra_sg[]/.  Because chaining consumes one sg
  entry.  There need to be two extra sg entries.  The renaming is also
  for future addition of other extra sg entries.

* Padding setup is moved into ata_sg_setup_extra() which is organized
  in a way that future addition of other extra sg entries is easy.

* qc->orig_n_elem is unused and removed.

* qc->n_elem now contains the number of sg entries that LLDs should
  map.  qc->mapped_n_elem is added to carry the original number of
  mapped sgs for unmapping.

* The last sg of the original sg list is used to chain to extra sg
  list.  The original last sg is pointed to by qc->last_sg and the
  content is stored in qc->saved_last_sg.  It's restored during
  ata_sg_clean().

* All sg walking code has been updated.  Unnecessary assertions and
  checks for conditions the core layer already guarantees are removed.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

With atapi_request_sense() converted to use sg, there's no user of
non-sg interface.  Kill non-sg interface.

* ATA_QCFLAG_SINGLE and ATA_QCFLAG_SG are removed.  ATA_QCFLAG_DMAMAP
  is used instead.  (this way no LLD change is necessary)

* qc->buf_virt is removed.

* ata_sg_init_one() and ata_sg_setup_one() are removed.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Cc: Rusty Russel <rusty@rustcorp.com.au>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Depending on how many bytes are transferred as a unit, PIO data
transfer may consume more bytes than requested.  Knowing how much
data is consumed is necessary to determine how much is left for
draining.  This patch update ->data_xfer such that it returns the
number of consumed bytes.

While at it, it also makes the following changes.

* s/adev/dev/
* use READ/WRITE constants for rw indication
* misc clean ups
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Add ATAPI command types - ATAPI_READ, WRITE, RW_BUF, READ_CD and MISC,
and implement atapi_cmd_type() which takes SCSI opcode and returns to
which class the opcode belongs.  This will be used later to improve
ATAPI handling.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Reimplement ata_acpi_cbl_80wire() using ata_acpi_gtm_xfermask() and
while at it relocate the function below ata_acpi_gtm_xfermask().

New ata_acpi_cbl_80wire() implementation takes @gtm, in both pata_via
and pata_amd, use the initial GTM value.  Both are trying to peek
initial BIOS configuration, so using initial caching value makes
sense.  This fixes ACPI part of cable detection in pata_amd which
previously always returned 0 because configuring PIO0 during reset
clears DMA configuration.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

libata-acpi is using separate timing tables for transfer modes
although libata-core has the complete ata_timing table.  Implement
ata_timing_cycle2mode() to look for matching mode given transfer type
and cycle duration and use it in libata-acpi and pata_acpi to replace
private timing tables.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Finding out matching transfer mode from ACPI GTM values is useful for
other purposes too.  Separate out the function and timing tables from
pata_acpi::pacpi_discover_modes().

Other than checking shared-configuration bit after doing
ata_acpi_gtm() in pacpi_discover_modes() which should be safe, this
patch doesn't introduce any behavior change.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

ATA_CBL_PATA_UNK indicates that the cable type can't be determined
from the host side and might be either 80c or 40c.  libata applies
drive or other generic limit in this case.  However, there are
controllers where both host and drive side detections are
misimplemented and the driver has to rely solely on private method -
peeking BIOS or ACPI configuration or using some other private
mechanism.

This patch adds ATA_CBL_PATA_IGN which tells libata to ignore the
cable type completely and just let the LLD determine the transfer mode
via host transfer mode masks and ->mode_filter().
Signed-off-by: NTejun Heo <htejun@gmail.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Jeff says xfer_mask is unsigned long not unsigned int.  Convert all
xfermask fields and handling functions to deal with unsigned longs.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

ata_id_to_dma_mode() isn't quite generic.  The function is basically
privately implemented ata_id_xfermask() combined with hardcoded mode
printing and configuration which are specific to ata_generic.

Kill the function and open code it in generic_set_mode() using generic
xfermode handling functions.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

* s/ATA_BITS_(PIO|MWDMA|UDMA)/ATA_NR_\1_MODES/g

* Consistently use 0xff to indicate invalid transfer mode (0x00 is
  valid for PIO_SLOW).

* Make ata_xfer_mode2mask() return proper mode mask instead of just
  the highest bit.

* Sort ata_timing table in increasing xfermode order and update
  ata_timing_find_mode() accordingly.

This patch doesn't introduce any behavior change.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Export the following xfermode related functions.

* ata_pack_xfermask()
* ata_unpack_xfermask()
* ata_xfer_mask2mode()
* ata_xfer_mode2mask()
* ata_xfer_mode2shift()
* ata_mode_string()
* ata_id_xfermask()
* ata_timing_find_mode()

These functions will be used later by LLD updates.  While at it,
change unsigned short @speed to u8 @xfer_mode in
ata_timing_find_mode() for consistency.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

ATA_DFLAG_DUBIOUS_XFER is set whenever data transfer speed or method
changes and gets cleared when data transfer command succeeds in the
newly configured transfer mode.

This will be used to improve speed down logic.

Signed-off-by: Tejun Heo <htejun@gmail.com<
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Clean up EH speed down implementation.

* is_io boolean variable is replaced eflags.  is_io is ATA_EFLAG_IS_IO.

* Error categories now have names.

* Better comments.

* Reorder 5min and 10min rules in ata_eh_speed_down_verdict()

* Use local variable @link to cache @dev->link in ata_eh_speed_down()

These changes are to improve readability and ease further changes.
This patch doesn't introduce any behavior change.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Area for DFLAGs which are cleared on INIT is full.  Extend it by 8
bits.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

With ATAPI transfer chunk size properly programmed, libata PIO HSM
should be able to handle full spurious data chunks.  Also, it's a good
idea to suppress trailing data warning for misc ATAPI commands as
there can be many of them per command - for example, if the chunk size
is 16 and the drive tries to transfer 510 bytes, there can be 31
trailing data messages.

This patch makes the following updates to libata ATAPI PIO HSM
implementation.

* Make it drain full spurious chunks.

* Suppress trailing data warning message for misc commands.

* Put limit on how many bytes can be drained.

* If odd, round up consumed bytes and the number of bytes to be
  drained.  This gets the number of bytes to drain right for drivers
  which do 16bit PIO.

This patch is partial backport of improve-ATAPI-data-xfer patchset
pending for #upstream.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

On certain implementations, _GTF evaluation depends on preceding _STM
and both can be pretty picky about the configuration.  Using _GTM
result cached during controller initialization satisfies the most
neurotic _STM implementation.  However, libata evaluates _GTF after
reset during device configuration and the hardware state can be
different from what _GTF expects and can cause evaluation failure.

This patch adds dev->gtf_cache and updates ata_dev_get_GTF() such that
it uses the cached value if available.  Cache is cleared with a call
to ata_acpi_clear_gtf().

Because for SATA ACPI nodes _GTF must be evaluated after _SDD which
can't be done till IDENTIFY is complete, _GTF caching from
ata_acpi_on_resume() is used only for IDE ACPI nodes.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

_GTM fetches currently configured transfer mode while _STM configures
controller according to _GTM parameter and prepares transfer mode
configuration TFs for _GTF.  In many cases _GTM and _STM
implementations are quite brittle and can't cope with configuration
changed by libata.

libata does not depend on ATA ACPI to configure devices.  The only
reason libata performs _GTM and _STM are to make _GTF evaluation
succeed and libata also doesn't care about how _GTF TFs configure
transfer mode.  It overrides that configuration anyway, so from
libata's POV, it doesn't matter what value is feeded to _STM as long
as evaluation succeeds for _STM and following _GTF.

This patch adds dev->__acpi_init_gtm and store initial _GTM values on
host initialization before modified by reset and mode configuration.
If the field is valid, ata_acpi_init_gtm() returns pointer to the
saved _GTM structure; otherwise, NULL.

This saved value is used for _STM during resume and peek at
BIOS/firmware programmed initial timing for later use.  The accessor
is there to make building w/o ACPI easy as dev->__acpi_init doesn't
exist if ACPI is not enabled.

On driver detach, the initial BIOS configuration is restored by
executing _STM with the initial _GTM values such that the next driver
can also use the initial BIOS configured values.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Make prink helpers format @lv together rather than prepending to the
format string as constant.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

* No internal function uses const ata_port.  Drop const from @ap.

* Make ata_acpi_stm() copy @stm before using it and change @stm to
  const.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

After an error condition, some ATAPI tape drives set DRQ=1 together
with ERR=1 when asking the host to transfer the CDB of the next packet
command (i.e. request sense).  This patch, a revised version of
Alan/Mark's previous patch, adds ATA_HORKAGE_STUCK_ERR to workaround
the problem by ignoring the ERR bit and proceed sending the CDB.
Signed-off-by: NAlbert Lee <albertcc@tw.ibm.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Mark Lord <liml@rtr.ca>
Signed-off-by: NTejun Heo <htejun@gmail.com>

This patch removes the following obsolete functions:
- libata-core.c: __sata_phy_reset()
- libata-core.c: sata_phy_reset()
- libata-eh.c: ata_qc_timeout()
- libata-eh.c: ata_eng_timeout()
Signed-off-by: NAdrian Bunk <bunk@kernel.org>
Signed-off-by: NTejun Heo <htejun@gmail.com>

One or two ancient drives predated the cable spec and didn't sent the
valid bits for the field. I had hoped to leave this out of libata as a
piece of historical annoyance but a recent CD drive shows the same bug so
we have to import support for it.

Same concept as Bartlomiej's changes old IDE except that as we have
centralised blacklists we can avoid keeping another private table of stuff
Signed-off-by: NAlan Cox <alan@redhat.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Implement ATA_QCFLAG_QUIET which indicates that there's no need to
report if the command fails with AC_ERR_DEV and set it for passthrough
commands.

Combined with previous changes, this now makes device errors for all
direct commands reported directly to the issuer without going through
EH actions and reporting.

Note that EH is still invoked after non-IO device errors to determine
the nature of the error and resume command execution (some controller
requires special care after error to continue).  It just performs
default maintenance after error, examines what's going on, realizes
that it's none of its business and reports the command failure without
logging any error messages.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Device Initiated Power Management, which is defined
in SATA 2.5 can be enabled for disks which support it.
This patch enables DIPM when the user sets the link
power management policy to "min_power".

Additionally, libata drivers can define a function
(enable_pm) that will perform hardware specific actions to
enable whatever power management policy the user set up
for Host Initiated Power management (HIPM).
This power management policy will be activated after all
disks have been enumerated and intialized.  Drivers should
also define disable_pm, which will turn off link power
management, but not change link power management policy.

Documentation/scsi/link_power_management_policy.txt has additional
information.
Signed-off-by: NKristen Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

On certain device/controller combination, 0xff status is asserted
after reset and doesn't get cleared during 150ms post-reset wait.  As
0xff status is interpreted as no device (for good reasons), this can
lead to misdetection on such cases.

This patch implements ata_wait_after_reset() which replaces the 150ms
sleep and waits upto ATA_TMOUT_FF_WAIT if status is 0xff.
ATA_TMOUT_FF_WAIT is currently 800ms which is enough for
HHD424020F7SV00 to get detected but not enough for Quantum GoVault
drive which is known to take upto 2s.

Without parallel probing, spending 2s on 0xff port would incur too
much delay on ata_piix's which use 0xff to indicate empty port and
doesn't have SCR register, so GoVault needs to wait till parallel
probing.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NJeff Garzik <jeff@garzik.org>