Simplify tf_read() method, making it deal only with 'struct ide_taskfile' and
the validity flags that the upper layer passes, and factoring out the code that
deals with the high order bytes into ide_tf_readback() to be called from the
only two functions interested, ide_complete_cmd() and ide_dump_sector().

This should stop the needless code duplication in this method and so make
it about twice smaller than it was; along with simplifying the setup for
the method call, this should save both time and space...

Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Simplify tf_load() method, making it deal only with 'struct ide_taskfile' and
the validity flags that the upper layer passes, and moving the code that deals
with the high order bytes into the only function interested, do_rw_taskfile().

This should stop the needless code duplication in this method and so make
it about twice smaller than it was; along with simplifying the setup for the
method call, this should save both time and space...

Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Move device register masking (and setting drive->select) out of tf_load() method
and into the only function that needs to use this code, do_rw_taskfile()...

Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
[bart: fix whitespace error]
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Make 'struct ide_taskfile' cover only 8 register values and thus put two such
fields ('tf' and 'hob') into 'struct ide_cmd', dropping unnecessary 'tf_array'
field from it.

This required changing the prototype of ide_get_lba_addr() and ide_tf_dump().

Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
[bart: fix setting of ATA_LBA bit for LBA48 commands in __ide_do_rw_disk()]
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Replace IDE_TFLAG_{IN|OUT}_* flags meaning to the taskfile register validity on
input/output by the IDE_VALID_* flags and introduce 4 symmetric 8-bit register
validity indicator subfields, 'valid.{input/output}.{tf|hob}', into the 'struct
ide_cmd' instead of using the 'tf_flags' field for that purpose (this field can
then be turned from 32-bit into 8-bit one).

Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Move IDE_FTFLAG_{IN|OUT}_DATA flag handling out of tf_{read|load}() methods
into the only two functions where these flags actually need to be handled:
do_rw_taskfile() and ide_complete_cmd()...

Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Turn set_irq() method with its software reset hack into write_devctl() method
(for just writing a value into the device control register) at last...

Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

* Add ide_dma_prepare() helper.

* Convert ide_issue_pc() and do_rw_taskfile() to use it.

* Make ide_build_sglist() static.

There should be no functional changes caused by this patch.

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

* Export ide_pio_bytes().

* Add ->last_xfer_len field to struct ide_cmd.

* Add ide_cd_error_cmd() helper to ide-cd.

* Convert ide-cd to use scatterlists also for PIO transfers (fs requests
  only for now) and get rid of partial completions (except when the error
  happens -- which is still subject to change later because looking at
  ATAPI spec it seems that the device is free to error the whole transfer
  with setting the Error bit only on the last transfer chunk).

* Update ide_cd_{prepare_rw,restore_request,do_request}() accordingly.

* Inline ide_cd_restore_request() into cdrom_start_rw().

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

Use PageHighMem() instead of ifdefs in ide_pio_bytes()
(=> local IRQs won't be disabled when not necessary).

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