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). Port resets are deferred whenever a device on that
port is in the parked state.

v3:
Elias Oltmanns <eo@nebensachen.de> wrote:
[...]
> >> 1. Make sure that no negative value is being passed to
> >>    jiffies_to_msecs() in ide_park_show().
> >> 2. Drop the superfluous variable hwif in ide_special_rq().
> >> 3. Skip initialisation of task and tf in ide_special_rq() if we are not
> >>    handling a (un)park request.
> >
> > Well, #3 should have been done differently because we donn't want to
> > check for REQ_(UN)?PARK_HEADS more often than is necessary.
> 
> While preparing the backport to 2.6.27, it has just occurred to me that
> we need to clear the IDE_DFLAG_PARKED flag in ide_disk_pre_reset()
> because this flag must not be set after *any* sort of access to the
> device.

v4:
Fix a memory leak due to a missing blk_put_request() in
issue_park_cmd(). Additionally, we should plug the queue when enqueueing
the unpark request because there is no guarantee that the park timeout
has not expired by then. Even though the chance for that to happen is
very slim, the request might end up hanging in the queue until the next
I/O operation is queued up. While at it, clean up the code a little:
- make issue_park_cmd() a function of type void since nobody cares for
  the return value anyway;
- use blk_start_queueing() instead of __blk_run_queue() since we don't
  have to worry about recursion;
- remove a superfluous pointer deference in task_no_data_intr().
Signed-off-by: NElias Oltmanns <eo@nebensachen.de>
Cc: Jeff Garzik <jeff@garzik.org>,
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Tejun Heo <htejun@gmail.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

In function ide_devset_execute() we should use __GFP_WAIT rather than
GFP_KERNEL. Also, the allocation cannot possibly fail at that point.
More importantly, there is a potential memory leak in the device probing
code. The infrastructure seems rather complex and I hope I haven't messed
anything up by trying to fix this.
Signed-off-by: NElias Oltmanns <eo@nebensachen.de>
[bart: remove superfluous ide_lock taking]
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

* Rename ->ide_dma_clear_irq method to ->clear_irq
  and move it from ide_hwif_t to struct ide_port_ops.

* Move ->waiting_for_dma check inside ->clear_irq method.

* Move ->dma_base check inside ->clear_irq method.

piix.c:
* Add ich_port_ops and remove init_hwif_ich() wrapper.

There should be no functional changes caused by this patch.
Acked-by: NSergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

* Convert 'pio_mode' device setting to use DS_SYNC flag.

* Remove unused special_t.b.{set_tune,serviced} and ide_drive_t.tune_req.
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

* Use 'drive->dn & 1' in ide_init_disk().

* remove [ata_]select_t.

While at it:

* Use ATA_DEVICE_OBS define in ide_port_init_devices_data().
Acked-by: NSergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

* Move ide*_pm_* enums from ide-io.c to <linux/ide.h>.

* idedisk_pm_* -> ide_pm_*

* ide_pm_state_* -> ide_pm_*

* No need to set ide_pm_* enums to the fixed values.

* Uppercase ide_pm_* enums.

* Fix/update comments.
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Add IDE_DFLAG_LBA device flag and use it instead of ->select.b.lba.

Since ->tf_load uses ->select.all for ATA Device/Head register this
fixes HDIO_DRIVE_TASK[FILE] ioctls for CHS commands on LBA devices.
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Add IDE_DFLAG_DMA_PIO_RETRY and use it instead of
ide_drive_t.state + DMA_PIO_RETRY.

There should be no functional changes cause by this patch.
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Add 'unsigned long dev_flags' to ide_drive_t and convert bitfields
to IDE_DFLAG_* flags.

While at it:
- IDE_DFLAG_ADDRESSING -> IDE_DFLAG_LBA48
- fixup some comments
- remove needless g->flags zeroing from ide*_probe()

There should be no functional changes caused by this patch.
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Use a special request for serialisation purposes and get rid of the
awkward ide_spin_wait_hwgroup(). This also involves converting the
ide_devset structure so it can be shared by the /proc and the ioctl code.
Signed-off-by: NElias Oltmanns <eo@nebensachen.de>
[bart: use rq->cmd[] directly]
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

* Add ata_id_flush_ext_enabled() inline helper to <linux/ata.h>.

* ide_id_has_flush_cache_ext() -> ata_id_flush_ext_enabled()

  The latter one also checks if the command is marked as
  supported in word 83 and validity of words 83 & 86.

Cc: Jeff Garzik <jgarzik@pobox.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

* Add ata_id_flush_enabled() inline helper to <linux/ata.h>.

* ide_id_has_flush_cache() -> ata_id_flush_enabled()

  The latter one also checks if the command is marked as
  supported in word 83 and validity of words 83 & 86.

Cc: Jeff Garzik <jgarzik@pobox.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

* Include <linux/ata.h> directly in <linux/ide.h>
  instead of through <linux/hdreg.h>.

* Include <linux/hdreg.h> only when needed.

Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Remove ->remap_0_to_1 and ->sect0 (they are always zero now).
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

* ERR_STAT   -> ATA_ERR
* INDEX_STAT -> ATA_IDX
* ECC_STAT   -> ATA_CORR
* DRQ_STAT   -> ATA_DRQ
* SEEK_STAT  -> ATA_DSC
* WRERR_STAT -> ATA_DF
* READY_STAT -> ATA_DRDY
* BUSY_STAT  -> ATA_BUSY

* MARK_ERR   -> ATA_AMNF
* TRK0_ERR   -> ATA_TRK0NF
* ABRT_ERR   -> ATA_ABORTED
* MCR_ERR    -> ATA_MCR
* ID_ERR     -> ATA_IDNF
* MC_ERR     -> ATA_MC
* ECC_ERR    -> ATA_UNC
* ICRC_ERR   -> ATA_ICRC

* BBD_ERR    -> ATA_BBK

Also:

* ILI_ERR    -> ATAPI_ILI
* EOM_ERR    -> ATAPI_EOM
* LFS_ERR    -> ATAPI_LFS

* CD         -> ATAPI_COD
* IO         -> ATAPI_IO
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

* Use ATA_CMD_* defines instead of WIN_* ones.

While at it:

* EXABYTE_ENABLE_NEXT -> ATA_EXABYTE_ENABLE_NEST

* SETFEATURES_{EN,DIS}_WCACHE -> SETFEATURES_WC_{ON,OFF}

* SETFEATURES_{EN,DIS}_AAM -> SETFEATURES_AAM_{ON,OFF}

* SMART_* -> ATA_SMART_*

* Remove stale comment from ide-proc.c.

Partially based on earlier work by Chris Wedgwood.
Acked-by: NChris Wedgwood <cw@f00f.org>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

This condition is checked by both ide_disk_init_mult_count()
and set_multcount() so no need to do it again in ide_disk_special().
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

* Add struct ide_tp_ops for transport methods.

* Add 'const struct ide_tp_ops *tp_ops' to struct ide_port_info
  and ide_hwif_t.

* Set the default hwif->tp_ops in ide_init_port_data().

* Set host driver specific hwif->tp_ops in ide_init_port().

* Export ide_exec_command(), ide_read_status(), ide_read_altstatus(),
  ide_read_sff_dma_status(), ide_set_irq(), ide_tf_{load,read}()
  and ata_{in,out}put_data().

* Convert host drivers and core code to use struct ide_tp_ops.

* Remove no longer needed default_hwif_transport().

* Cleanup ide_hwif_t from methods that are now in struct ide_tp_ops.

While at it:

* Use struct ide_port_info in falconide.c and q40ide.c.

* Rename ata_{in,out}put_data() to ide_{in,out}put_data().

v2:

* Fix missing convertion in ns87415.c.

There should be no functional changes caused by this patch.
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Add ->set_irq method for setting nIEN bit of ATA Device Control
register and use it instead of ide_set_irq().

While at it:

* Use ->set_irq in init_irq() and do_reset1().

* Don't use HWIF() macro in ide_check_pm_state().

There should be no functional changes caused by this patch.
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

* Remove ide_read_status() inline helper.

* Add ->read_status method for reading ATA Status register
  and use it instead of ->INB.

While at it:

* Don't use HWGROUP() macro.

There should be no functional changes caused by this patch.
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Add ->exec_command method for writing ATA Command register
and use it instead of ->OUTBSYNC.

There should be no functional changes caused by this patch.
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Remove some code which has been made obsolete and hasn't worked properly
before anyway.  Part of the infrastructure may be reintroduced in a
follow up patch to implement a working command aborting facility.
Signed-off-by: NElias Oltmanns <eo@nebensachen.de>
Cc: "Alan Cox" <alan@lxorguk.ukuu.org.uk>
Cc: "Randy Dunlap" <randy.dunlap@oracle.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Currently, the code path executing an HDIO_DRIVE_RESET ioctl is broken
in various ways.  Most importantly, it is treated as an out of band
request in an illegal way which may very likely lead to system lock ups.
Use the drive's request queue to avoid this problem (and fix a locking
issue for free along the way).
Signed-off-by: NElias Oltmanns <eo@nebensachen.de>
Cc: "Alan Cox" <alan@lxorguk.ukuu.org.uk>
Cc: "Randy Dunlap" <randy.dunlap@oracle.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

ide_do_drive_cmd is called only with ide_preempt action argument. So
we can remove the action argument in ide_do_drive_cmd and ide_action_t
typedef.

This patch also includes two minor cleanups: 1) ide_do_drive_cmd
always succeeds so we don't need the return value; 2) the callers use
blk_rq_init before ide_do_drive_cmd so there is no need to initialize
rq->errors.
Signed-off-by: NFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Borislav Petkov <petkovbb@gmail.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

There should be no functional changes caused by this patch.
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Move IRQ unmasking out from ->tf_load method to its users.

There should be no functional changes caused by this patch
(SELECT_MASK() is NOP except for hpt366, icside and sgiioc4).
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Just use the new & shiny ide_pad_transfer() helper instead.

Also remove the superfluous check for 'drive->media == ide_disk'
while at it (ide_ata_error() is used only for ide_disk devices).
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

ide_init_drive_cmd just calls blk_rq_init. This converts the users of
ide_init_drive_cmd to use blk_rq_init directly and removes
ide_init_drive_cmd.
Signed-off-by: NFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Borislav Petkov <petkovbb@gmail.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Now all the users of ide_do_drive_cmd using ide_wait/head_wait are
converted to use blk_execute_rq this removes the ide_wait/head_wait
path in ide_do_drive_cmd.
Signed-off-by: NFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Borislav Petkov <petkovbb@gmail.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

* Call __elv_add_request() with 'plug' == 1 (so the device will be
  plugged) and then use __generic_unplug_device() instead of calling
  ide_do_request() directly.

v2:
* For blk_pm_resume_request() requests the queue is stopped so we
  need to call ->request_fn explicitly.

  Thanks to:
  - Rafael for reporting/bisecting the bug
  - Borislav/Rafael for testing the fix

This is a preparation for converting IDE to use blk_execute_rq().

Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Borislav Petkov <petkovbb@gmail.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

* Set REQ_PREEMPT request flag in ide_do_drive_cmd() users
  for ide_preempt and ide_head_wait action types.

* Remove setting REQ_PREEMPT from ide_do_drive_cmd().

While at it:

* Set 'where' variable outside ide_lock.

This is a preparation for converting IDE to use blk_execute_rq().

There should be no functional changes caused by this patch.

Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Borislav Petkov <petkovbb@gmail.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

This converts ide to use blk_rq_init to initialize the request.

This is a preparation for large command support, which needs to
initialize the request in a proper way (that is, just doing a memset()
will not work).
Signed-off-by: NFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Jens Axboe <jens.axboe@oracle.com>
Cc: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Signed-off-by: NJens Axboe <jens.axboe@oracle.com>

* Add ide_pad_transfer() helper (which uses ->{in,out}put_data methods
  internally so the transfer is also padded to drive+host requirements)
  and use it instead of ide_atapi_{write_zeros,discard_data}().

* Remove no longer needed ide_atapi_{write_zeros,discard_data}().

Cc: Borislav Petkov <petkovbb@gmail.com>
Acked-by: NSergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

* Add ->tf_load and ->tf_read methods to ide_hwif_t and set the default
  methods in default_hwif_transport().

* Use ->tf_{load,read} instead o calling ide_tf_{load,read}() directly.

* Make ide_tf_{load,read}() static.

There should be no functional changes caused by this patch.
Acked-by: NSergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Factor out debugging code from ide_tf_load() to ide_tf_dump() helper
and update ide_tf_load() users accordingly.
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Always use ->OUTBSYNC method for executing commands so the posting is done
if needed (this affects only pmac and scc_pata host drivers at the moment).
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

* Merge ->atapi_{in,out}put_bytes and ->ata_{in,out}put_data methods
  into new ->{in,out}put_data methods which take number of bytes to
  transfer as an argument and always do padding.

While at it:

* Use 'hwif' or 'drive->hwif' instead of 'HWIF(drive)'.

There should be no functional changes caused by this patch (all users
of ->ata_{in,out}put_data methods were using multiply-of-4 word counts).
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

* Add ->atapi_{in,out}put_bytes and ->ata_{in,out}put_data methods to
  falconide and q40ide host drivers (->ata_* methods are implemented on
  top of ->atapi_* methods so they also do byte-swapping now).

* Cleanup atapi_{in,out}put_bytes().

v2:
* Add 'struct request *rq' argument to ->ata_{in,out}put_data methods
  and don't byte-swap disk fs requests (we shouldn't un-swap fs requests
  because fs itself is stored byte-swapped on the disk) - this is how
  things were done before the patch (ideally device mapper should be
  used instead but it would break existing setups and would have some
  performance impact).

Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Michael Schmitz <schmitz@debian.org>
Cc: Roman Zippel <zippel@linux-m68k.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Richard Zidlicky <rz@linux-m68k.org>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

* Add struct ide_io_ports and use it instead of `unsigned long io_ports[]`
  in ide_hwif_t.

* Rename io_ports[] in hw_regs_t to io_ports_array[].

* Use un-named union for 'unsigned long io_ports_array[]' and 'struct
  ide_io_ports io_ports' in hw_regs_t.

* Remove IDE_*_OFFSET defines.

v2:
* scc_pata.c build fix from Stephen Rothwell.

v3:
* Fix ctl_adrr typo in Sparc-specific part of ns87415.c.
  (Noticed by Andrew Morton)
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>