Get rid of the pipeline merge stage but retain the chrdev req caching
functionality by using a merge buffer tape->merge_bh which is flushed in chunks
of several blocks at a time. Also, remove last references to pipelining, e.g.
typedef idetape_stage_s.
Signed-off-by: NBorislav Petkov <petkovbb@gmail.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

This is the size of the merge buffer.
Signed-off-by: NBorislav Petkov <petkovbb@gmail.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

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

Also, rename its __-low level helper too.
Signed-off-by: NBorislav Petkov <petkovbb@gmail.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

It always returns 0 which has no effect on tape positioning calculation so
simplify it by converting its type to void, bringing no functional change to the
driver.
Signed-off-by: NBorislav Petkov <petkovbb@gmail.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Instead of freeing pages one by one, free them 2^order-wise. Also, mv
__idetape_kfree_stage() to ide_tape_kfree_buffer().

[bart: add updating bh->b_data]
Signed-off-by: NBorislav Petkov <petkovbb@gmail.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

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

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

Instead of allocating pages for the buffer one by one, take advantage of the
buddy alloc system and request them 2^order at a time. This increases the chance
for bigger buffer parts to be contigious and reduces loop iteration count. While
at it, rename function __idetape_kmalloc_stage() to ide_tape_kmalloc_buffer().

[bart: fold with "ide-tape: fix mem leak" patch to preserve bisectability]
Signed-off-by: NBorislav Petkov <petkovbb@gmail.com>
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>

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

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

Bart:
- merge "ide-tape: remove pipeline-specific code from idetape_setup" patch
- cleanup __idetape_discard_read_pipeline()
- cleanup idetape_empty_write_pipeline()
- fix 't' assignment in idetape_setup()
- fix idetape_blkdev_ioctl() w.r.t. 'nr_stages'
Signed-off-by: NBorislav Petkov <petkovbb@gmail.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

[bart: sync patch with current code and fix idetape_init_read()]
Signed-off-by: NBorislav Petkov <petkovbb@gmail.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

The driver is using now solely its own request queue.

- tape->next_stage is always NULL so it is safe to remove
  all code depending on tape->next_stage != NULL

- this patch removes the last place which sets
  IDETAPE_FLAG_PIPELINE_ACTIVE in tape->flags

[bart: add above explanations]
Signed-off-by: NBorislav Petkov <petkovbb@gmail.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

idetape_queue_pc_tail() is a wrapper for its __idetape_queue_pc_tail() counterpart
and has no other functionality. Remove it and call the "wrapped" function
directly.
Signed-off-by: NBorislav Petkov <petkovbb@gmail.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

As a side effect, remove unused idetape_kfree_stage() and
idetape_abort_pipeline()

[bart: resurrect taking tape->lock + clearing IDETAPE_FLAG_PIPELINE_ACTIVE]
Signed-off-by: NBorislav Petkov <petkovbb@gmail.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

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

The computation of the block offset of the the tape position (MTIOCPOS,
MTIOCGET) is not influenced by the stages queued in the pipeline anymore but by
the size of the current buffer which is going to be sent to the drive.

[bart: resurrect deleted idetape_wait_for_pipeline() call]
Signed-off-by: NBorislav Petkov <petkovbb@gmail.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Since we don't do pipeline read-ahead anymore, we don't have to look for
filemarks we have crossed. Therefore, remove the code chunk that does that and
pass on the command to the tape. As a side effect, remove unused
idetape_wait_first_stage().
Signed-off-by: NBorislav Petkov <petkovbb@gmail.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

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

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

In order to do away with queueing read requests on the pipeline, several things
have to be done:

1. Do not allocate additional pipeline stages in idetape_init_read() until
(tape->nr_stages < max_stages) and do only read operation preparations. As a
collateral result, idetape_add_stage_tail() becomes unused so remove it.

2. Queue the read request's buffer directly thru idetape_queue_rw_tail().

3. Remove now unused idetape_kmalloc_stage() and idetape_switch_buffers().

[bart: simplify the original patch]
Signed-off-by: NBorislav Petkov <petkovbb@gmail.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Pipeline handling calculations in idetape_calculate_speeds() can
go since they do not have any effect on other functionality besides:

1. info is only being exported through /proc as a read-only item
(controlled_pipeline_head_speed, uncontrolled_pipeline_head_speed)

2. used in idetape_restart_speed_control() which, in turn, is unrelated to
other code

3. used only for pipeline frames number accounting (tape->pipeline_head),
also unused elsewhere.

4.some variables are:
        only written to: tape->buffer_head;
        unused: tape->tape_head, tape->last_tape_head
Signed-off-by: NBorislav Petkov <petkovbb@gmail.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Refrain from adding more write requests to the pipeline and queue them
directly on the device's request queue instead.

[bart: re-do for minimal behavior changes]
Signed-off-by: NBorislav Petkov <petkovbb@gmail.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Prior to allocating a new pipeline stage, the code checked for the existence of
a cached pipeline stage to use. Do away with and stick to normal pipeline
stages only.

[bart: keep idetape_kmalloc_stage() for now]
Signed-off-by: NBorislav Petkov <petkovbb@gmail.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Add struct ide_dma_ops and convert core code + drivers to use it.

While at it:

* Drop "ide_" prefix from ->ide_dma_end and ->ide_dma_test_irq methods.

* Drop "ide_" "infixes" from DMA methods.

* au1xxx-ide.c:
  - use auide_dma_{test_irq,end}() directly in auide_dma_timeout()

* pdc202xx_old.c:
  - drop "old_" "infixes" from DMA methods

* siimage.c:
  - add siimage_dma_test_irq() helper
  - print SATA warning in siimage_init_one()

* Remove no longer needed ->init_hwif implementations.

v2:
* Changes based on review from Sergei:
  - s/siimage_ide_dma_test_irq/siimage_dma_test_irq/
  - s/drive->hwif/hwif/ in idefloppy_pc_intr().
  - fix patch description w.r.t. au1xxx-ide changes
  - fix au1xxx-ide build
  - fix naming for cmd64*_dma_ops
  - drop "ide_" and "old_" infixes
  - s/hpt3xxx_dma_ops/hpt37x_dma_ops/
  - s/hpt370x_dma_ops/hpt370_dma_ops/
  - use correct DMA ops for HPT302/N, HPT371/N and HPT374
  - s/it821x_smart_dma_ops/it821x_pass_through_dma_ops/

v3:
* Two bugs slipped in v2 (noticed by Sergei):
  - use correct DMA ops for HPT374 (for real this time)
  - handle HPT370/HPT370A properly
Acked-by: NSergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

This function was simply a wrapper for a test_bit() macro so remove it and
use the macro instead.
Signed-off-by: NBorislav Petkov <petkovbb@gmail.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

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

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

Removing the atomic tests for pc's is unobjectionable. Since this driver will
probably go to /dev/null soon, the atomic tests for tape->flags are left in
place for there are some situations where they're needed (chrdev DSC handling,
low level pipeline operation and so on). While at it, rename all test/set flag
bit defines explicitly to *_FLAG_* for clarity.
Signed-off-by: NBorislav Petkov <petkovbb@gmail.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Bart:
- no need to move defines for tape flags around
  (they are completely rewritten by the next patch)
Signed-off-by: NBorislav Petkov <petkovbb@gmail.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

* Add IDE_{ALTSTATUS,IREASON,BCOUNTL,BCOUNTH}_OFFSET defines.

* Remove IDE_*_REG macros - this results in more readable
  and slightly smaller code.

There should be no functional changes caused by this patch.

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

Add ide_atapi_{discard_data,write_zeros} inline helpers to <linux/ide.h>
and use them instead of home-brewn helpers in ide-{floppy,tape,scsi}.

There should be no functional changes caused by this patch.

Cc: Borislav Petkov <petkovbb@gmail.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

This reverts commit d48567dd.

Borislav is working on ide-tape "light" version instead.

Cc: Borislav Petkov <petkovbb@gmail.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

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

rq->cmd[0] is never set to REQ_IDETAPE_READ_BUFFER so remove
REQ_IDETAPE_READ_BUFFER handling from idetape_create_write_cmd()
and the define itself.

Then remove no longer used idetape_create_read_buffer_cmd()
and IDETAPE_RETRIEVE_FAULTY_BLOCK define.

There should be no functional changes caused by this patch.

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

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

... thus decreasing checkpatch.pl errors to 0.

Bart:
- remove needless function prototypes while at it
- remove needless parentheses while at it
- add missing KERN_ level to ide_tape_probe()
- other minor fixups
Signed-off-by: NBorislav Petkov <petkovbb@gmail.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Spotted by Sergei Shtylyov.

CC: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: NBorislav Petkov <petkovbb@gmail.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>