Now that disk and partition handlings are mostly unified, it's easy to
allow disk to have extended device number.  This patch makes
add_disk() use extended device number if disk->minors is zero.  Both
sd and ide-disk are updated to use this.

* sd_format_disk_name() is implemented which can generically determine
  the drive name.  This removes disk number restriction stemming from
  limited device names.

* If sd index goes over SD_MAX_DISKS (which can be increased now BTW),
  sd simply doesn't initialize minors letting block layer choose
  extended device number.

* If CONFIG_DEBUG_EXT_DEVT is set, both sd and ide-disk always set
  minors to 0 and use extended device numbers.
Signed-off-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NJens Axboe <jens.axboe@oracle.com>

With previous changes, it's meaningless to limit the number of
partitions.  Replace @ext_minors with GENHD_FL_EXT_DEVT such that
setting the flag allows the disk to have maximum number of allowed
partitions (only limited by the number of entries in parsed_partitions
as determined by MAX_PART constant).

This kills not-too-pretty alloc_disk_ext[_node]() functions and makes
@minors parameter to alloc_disk[_node]() unnecessary.  The parameter
is left alone to avoid disturbing the users.
Signed-off-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NJens Axboe <jens.axboe@oracle.com>

Extended devt introduces non-contiguos device numbers.  This patch
implements a debug option which forces most devt allocations to be
from the extended area and spreads them out.  This is enabled by
default if DEBUG_KERNEL is set and achieves...

1. Detects code paths in kernel or userland which expect predetermined
   consecutive device numbers.

2. When something goes wrong, avoid corruption as adding to the minor
   of earlier partition won't lead to the wrong but valid device.
Signed-off-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NJens Axboe <jens.axboe@oracle.com>

Update sd and ide-disk such that they can take advantage of extended
minors.

ide-disk already has 64 minors per device and currently doesn't use
extended minors although after this patch it can be turned on by
simply tweaking constants.

sd only had 16 minors per device causing problems on certain peculiar
configurations.  This patch lifts the restriction and enables it to
use upto 64 minors.
Signed-off-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NJens Axboe <jens.axboe@oracle.com>

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

On Monday 28 July 2008, Benjamin Herrenschmidt wrote:

[...]

> Vector: 300 (Data Access) at [c58b7b80]
>     pc: c014f264: elv_may_queue+0x10/0x44
>     lr: c0152750: get_request+0x2c/0x2c0
>     sp: c58b7c30
>    msr: 1032
>    dar: c
>  dsisr: 40000000
>   current = 0xc58aaae0
>     pid   = 854, comm = media-bay
> enter ? for help
> mon> t
> [c58b7c40] c0152750 get_request+0x2c/0x2c0
> [c58b7c70] c0152a08 get_request_wait+0x24/0xec
> [c58b7cc0] c0225674 ide_cd_queue_pc+0x58/0x1a0
> [c58b7d40] c022672c ide_cdrom_packet+0x9c/0xdc
> [c58b7d70] c0261810 cdrom_get_disc_info+0x60/0xd0
> [c58b7dc0] c026208c cdrom_mrw_exit+0x1c/0x11c
> [c58b7e30] c0260f7c unregister_cdrom+0x84/0xe8
> [c58b7e50] c022395c ide_cd_release+0x80/0x84
> [c58b7e70] c0163650 kref_put+0x54/0x6c
> [c58b7e80] c0223884 ide_cd_put+0x40/0x5c
> [c58b7ea0] c0211100 generic_ide_remove+0x28/0x3c
> [c58b7eb0] c01e9d34 __device_release_driver+0x78/0xb4
> [c58b7ec0] c01e9e44 device_release_driver+0x28/0x44
> [c58b7ee0] c01e8f7c bus_remove_device+0xac/0xd8
> [c58b7f00] c01e7424 device_del+0x104/0x198
> [c58b7f20] c01e74d0 device_unregister+0x18/0x30
> [c58b7f40] c02121c4 __ide_port_unregister_devices+0x6c/0x88
> [c58b7f60] c0212398 ide_port_unregister_devices+0x38/0x80
> [c58b7f80] c0208ca4 media_bay_step+0x1cc/0x5c0
> [c58b7fb0] c0209124 media_bay_task+0x8c/0xcc
> [c58b7fd0] c00485c0 kthread+0x48/0x84
> [c58b7ff0] c0011b20 kernel_thread+0x44/0x60

The guilty commit turned out to be 08da591e
("ide: add ide_device_{get,put}() helpers").  ide_device_put() is called
before kref_put() in ide_cd_put() so IDE device is already gone by the time
ide_cd_release() is reached.

Fix it by calling ide_device_get() before kref_get() and ide_device_put()
after kref_put() in all affected device drivers.

v2:
Brown paper bag time.  In v1 cd->drive was referenced after dropping last
reference on cd object (which could result in OOPS in ide_device_put() as
reported/debugged by Mariusz Kozlowski).  Fix it by caching cd->drive in
the local variable (fix other device drivers too).
Reported-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Reported-by: NMariusz Kozlowski <m.kozlowski@tuxland.pl>
Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Borislav Petkov <petkovbb@gmail.com>
Tested-by: NMariusz Kozlowski <m.kozlowski@tuxland.pl>
Tested-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

* Add 'struct ide_host *host' field to ide_hwif_t and set it
  in ide_host_alloc_all().

* Add ide_device_{get,put}() helpers loosely based on SCSI's
  scsi_device_{get,put}() ones.

* Convert IDE device drivers to use ide_device_{get,put}().
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Lets remove dead Virtual DMA support for now so it doesn't clutter
core IDE code (it can be bring back when there is a need for it):

* Remove IDE_HFLAG_VDMA host flag.

* Remove ide_drive_t.vdma flag.

* cs5520.c: remove stale FIXMEs, cs5520_dma_host_set() and cs5520_dma_ops
  (also there is no longer a need to set IDE_HFLAG_NO_ATAPI_DMA).

There should be no functional changes caused by this patch.

Cc: TAKADA Yoshihito <takada@mbf.nifty.com>
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>

Always call SELECT_MASK(..., 0) in ide_tf_load() (needs to be done
to match ide_set_irq(..., 1)) and then remove IDE_TFLAG_NO_SELECT_MASK
taskfile flag.

This change should only affect hpt366 and icside host drivers since
->maskproc(..., 0) for sgiioc4 is equivalent to ide_set_irq(..., 1).

Cc: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

This converts the ide_do_drive_cmd path using ide_wait to use
blk_execute_rq.
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>

There are no changes to the resulting drivers/ide/ide-disk.o binary file
(md5sum-s after and before the patch match).
Acked-by: NSergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

* Factor out common code from proc_idedisk_read_smart_{thresholds,values}()
  to proc_idedisk_read_smart() helper.

* Rename proc_idedisk_read_smart_thresholds() to proc_idedisk_read_st()
  and proc_idedisk_read_smart_values() to proc_idedisk_read_sv().

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

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

Signed-off-by: NMikko Rapeli <mikko.rapeli@teleca.com>
Tested-by: NBart Champagne <bart@as35701.net>
Cc: Jeff Garzik <jgarzik@pobox.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

commit 813a0eb2
Author: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Date:   Fri Jan 25 22:17:10 2008 +0100

    ide: switch idedisk_prepare_flush() to use REQ_TYPE_ATA_TASKFILE requests

...

broke flush requests.

Allocating IDE command structure on the stack for flush requests is not
a very brilliant idea:

- idedisk_prepare_flush() only prepares the request and it doesn't wait
  for it to be completed

- there are can be multiple flush requests queued in the queue

Fix the problem (per hints from James Bottomley) by:
- dynamically allocating ide_task_t instance using kmalloc(..., GFP_ATOMIC)
- adding new taskfile flag (IDE_TFLAG_DYN)
- calling kfree() in ide_end_drive_command() if IDE_TFLAG_DYN is set
  (while at it rename 'args' to 'task' and fix whitespace damage)

[ This will be fixed properly before 2.6.25 but this bug is rather
  critical and the proper solution requires some more work + testing. ]

Thanks to Sebastian Siewior and Christoph Hellwig for reporting the
problem and testing patches (extra thanks to Sebastian for bisecting
it to the guilty commmit).
Tested-by: NSebastian Siewior <ide-bug@ml.breakpoint.cc>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Cc: Tejun Heo <htejun@gmail.com>
Cc: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

The last years stuff and a trip down memory lane...
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Delete filenames/versions from comments.

I'm leaving decisions about adding DRV_VERSION defines and MODULE_VERSION()-s
to maintainers of the respective drivers.

While at it:

* Remove unused VERSION define from ide.c.

* Remove unused/stale DRV_VERSION define from au1xxx-ide.c.
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Based on the previous work by Tejun Heo.

There should be no functionality changes caused by this patch.

Cc: Tejun Heo <htejun@gmail.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

* Add IDE_TFLAG_{HOB,TF,DEVICE} defines.

* Set IDE_TFLAG_IN_* flags in {do_rw,ide_no_data,ide_raw}_taskfile() users.

* Remove no longer needed ->tf_flags setup from ide_end_drive_cmd().

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

Remove broken disk byte-swapping support:
- it can cause a data corruption on SMP (or if using PREEMPT on UP)
- all data coming from disk are byte-swapped by taskfile_*_data() which
  results in incorrect identify data being reported by /proc/ide/ and IOCTLs
- "hdx=bswap/byteswap" kernel parameter has been broken on m68k host drivers
  (including Atari/Q40 ones) since 2.5.x days (because of 'hwif' zero-ing)
- byte-swapping is limited to PIO transfers (for working with TiVo disks on
  x86 machines using user-space solutions or dm-byteswap should result in
  much better performance because DMA can be used)

For previous discussions please see:

http://www.ussg.iu.edu/hypermail/linux/kernel/0201.0/0768.html
http://lkml.org/lkml/2004/2/28/111

[ I have dm-byteswap device mapper target if somebody is interested
  (patch is for 2.6.4 though but I'll dust it off if needed). ]
Acked-by: NSergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

* Dump taskfile HOB registers in ide_tf_load() (if DEBUG is defined).

* Remove no longer needed DEBUG code from __ide_do_rw_disk().
Acked-by: NSergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

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

* Export ide_get_lba_addr().

* Convert idedisk_{read_native,set}_max_address() to use ide_get_lba_addr().

* Remove incorrect comment from idedisk_read_native_max_address()
  (noticed by Sergei).

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

* Add IDE_TFLAG_DMA_PIO_FALLBACK taskfile flag to indicate the need
  to skip loading taskfile registers in do_rw_taskfile().

* Export do_rw_taskfile().

* Convert __ide_do_rw_disk() to use do_rw_taskfile().

* Unexport ide_tf_load().

* Unexport {pre_task_out,task_in}_intr() and make it static.

* Remove incorrect comment about do_rw_taskfile() from <linux/ide.h>.

There should be no functionality changes caused by this patch.

v2:
* Add missing blk_fs_request() check to task_dma_ok() (for VDMA).
Acked-by: NSergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

* Add ide_tf_set_cmd() helper for selecting/setting command and data phase
  (note: DMA data phases are there for completness, they are not required ATM).

* Set IDE_TFLAG_WRITE taskfile flag for write requests in __ide_do_rw_disk().

* Convert __ide_do_rw_disk() to use the new ide_tf_set_cmd() helper.

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

s/WAIT_CMD/WAIT_WORSTCASE/ to make the timeout the same as in do_rw_taskfile()
Acked-by: NSergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

* Use ->data_phase to set ->handler in do_rw_taskfile() instead of
  setting ->handler in callers of ide_raw_taskfile()/do_rw_taskfile().

* Unexport task_no_data_intr() and make it static.

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

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

Fix __ide_do_rw_disk() to use ->OUTBSYNC instead of ->OUTB
(needed for pmac and scc_pata host drivers).
Acked-by: NSergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

* Add 'data_buf' and 'nsect' variables in ide_taskfile_ioctl()
  to cache data buffer pointer and number of sectors to transfer
  (this allows us to have only one ide_diag_taskfile() call).

* Add IDE_TFLAG_WRITE taskfile flag and use it to check whether
  the REQ_RW request flag should be set.

* Move ->command_type handling from ide_diag_taskfile() to
  ide_taskfile_ioctl() and use ->req_cmd instead of ->command_type.

* Add 'nsect' parameter to ide_raw_taskfile().

* Merge ide_diag_taskfile() into ide_raw_taskfile().

* Initialize ->data_phase explicitly in idedisk_prepare_flush(),
  ide_start_power_step() and ide_disk_special().

* Remove no longer needed 'command_type' field from ide_task_t.

* Add #ifndef/#endif __KERNEL__ to <linux/hdreg.h> around no
  longer used by kernel IDE_DRIVE_TASK_* and TASKFILE_* defines.

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

Remove ata_nsector_t, ata_data_t (unused) and atapi_bcount_t.

While at it:
* replace 'HWIF(drive)' by 'hwif'
Acked-by: NSergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Based on the earlier work by Tejun Heo.

There should be no functionality changes caused by this patch.

Cc: Tejun Heo <htejun@gmail.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

* Set taskfile flags for REQ_TYPE_ATA_TASKFILE requests before
  adding the request to the queue.

* Cleanup execute_drive_cmd().

* Remove unnecessary writes to HOB taskfile registers when using
  LBA48 disk for the following cases:

  - Power Management requests
    (WIN_FLUSH_CACHE[_EXT], WIN_STANDBYNOW1, WIN_IDLEIMMEDIATE commands)

  - special commands (WIN_SPECIFY, WIN_RESTORE, WIN_SETMULT)

  - Host Protected Area support (WIN_READ_NATIVE_MAX, WIN_SET_MAX)

  - /proc/ide/ SMART support (WIN_SMART with SMART_ENABLE,
    SMART_READ_VALUES and SMART_READ_THRESHOLDS subcommands)

  - write cache enabling/disabling in ide-disk
    (WIN_SETFEATURES with SETFEATURES_{EN,DIS}_WCACHE)

  - write cache flushing in ide-disk (WIN_FLUSH_CACHE[_EXT])

  - acoustic management in ide-disk
    (WIN_SETFEATURES with SETFEATURES_{EN,DIS}_AAM)

  - door (un)locking in ide-disk (WIN_DOORLOCK, WIN_DOORUNLOCK)

  - /proc/ide/hd?/identify support (WIN_IDENTIFY)

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

* Add IDE_TFLAG_OUT_DEVICE taskfile flag to indicate the need of writing
  the Device register and handle it in ide_tf_load().

  Update ide_tf_load() and {do_rw,flagged}_taskfile() users accordingly.

* Use struct ide_taskfile and ide_tf_load() in execute_drive_cmd().

* Make the debugging code dump all taskfile registers for both
  REQ_ATA_TYPE_{CMD,TASK} requests and move it to ide_tf_load()
  so it also covers REQ_ATA_TYPE_TASKFILE requests.

There should be no functionality changes caused by this patch
(unless DEBUG is defined).
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Based on the earlier work by Tejun Heo.

* Move setting IDE_TFLAG_LBA48 taskfile flag from do_rw_taskfile()
  function to the callers.

* Add IDE_TFLAG_FLAGGED taskfile flag for flagged taskfiles coming
  from ide_taskfile_ioctl().  Check it instead of ->tf_out_flags.all.

* Add IDE_TFLAG_OUT_DATA taskfile flag to indicate the need to load
  IDE data register in ide_tf_load().

* Add IDE_TFLAG_OUT_* taskfile flags to indicate the need to load
  particular IDE taskfile registers in ide_tf_load().

* Update do_rw_taskfile() and ide_tf_load() users to set respective
  IDE_TFLAG_OUT_* taksfile flags.

* Add task_dma_ok() helper.

* Use IDE_TFLAG_FLAGGED taskfile flag to select HIHI mask in ide_tf_load().

* Use do_rw_taskfile() in flagged_taskfile().

* Remove no longer needed 'tf_out_flags' field from ide_task_t.

There should be no functionality changes caused by this patch.

Cc: Tejun Heo <htejun@gmail.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

* Add ide_no_data_taskfile() helper and convert ide_raw_taskfile() w/ NO DATA
  protocol users to use it instead.

* Set ->data_phase explicitly in ide_no_data_taskfile()
  (TASKFILE_NO_DATA is defined as 0x0000).

* Unexport task_no_data_intr().
Acked-by: NSergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Based on the earlier work by Tejun Heo.

* Add 'tf_flags' field (for taskfile flags) to ide_task_t.

* Add IDE_TFLAG_LBA48 taskfile flag for LBA48 taskfiles.

* Add IDE_TFLAG_NO_SELECT_MASK taskfile flag for __ide_do_rw_disk()
  which doesn't use SELECT_MASK() (looks like a bug but it requires
  some more investigation).

* Split off ide_tf_load() helper from do_rw_taskfile().

* Convert __ide_do_rw_disk() to use ide_tf_load().

There should be no functionality changes caused by this patch.

Cc: Tejun Heo <htejun@gmail.com>
Acked-by: NSergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Based on the earlier work by Tejun Heo.

There should be no functionality changes caused by this patch.

Cc: Tejun Heo <htejun@gmail.com>
Acked-by: NSergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Load IDE_SECTOR_REG after IDE_FEATURE_REG and IDE_NSECTOR_REG when using CHS.

This patch is basically a preparation for the next one which converts
__ide_do_rw_disk() to use struct ide_taskfile.

It shouldn't affect anything (just a usual paranoia to separate changes
which change the way in which hardware is accessed from code cleanups).
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>