The second argument to ata_qc_complete() was being used for two
purposes: communicate the ATA Status register to the completion
function, and indicate an error.  On legacy PCI IDE hardware, the latter
is often implicit in the former.  On more modern hardware, the driver
often completely emulated a Status register value, passing ATA_ERR as an
indication that something went wrong.

Now that previous code changes have eliminated the need to use drv_stat
arg to communicate the ATA Status register value, we can convert it to a
mask of possible error classes.

This will lead to more flexible error handling in the future.

Enforce access rules where appropriate.

If the compiler is smart enough, this may buy us an optimization or two
as a side effect.

     - merge ata_prot_to_cmd() and ata_dev_set_protocol() as
       ata_rwcmd_protocol()
     - pave road for read/write multiple support
     - remove usage of pre-cached command and protocol values and call
       ata_rwcmd_protocol() instead
Signed-off-by: NAlbert Lee <albertcc@tw.ibm.com>

==============
Signed-off-by: NJeff Garzik <jgarzik@pobox.com>

  - change "xlat" and "fill" actors in libata-scsi so
    they are responsible for SCSI status and sense data
    when they return 1. This allows GOOD status or a
    specialized error to be set.
  - yield an error for mode sense requests for saved
    values [sat-r06]
  - remove static inlines for ata_bad_scsiop() and
    ata_bad_cdb() which are no longer used
Signed-off-by: NDouglas Gilbert <dougg@torque.net>
Signed-off-by: NJeff Garzik <jgarzik@pobox.com>

  - add extern ata_scsi_set_sense() to build SCSI
    fixed sense data and corresponding SCSI status
Signed-off-by: NDouglas Gilbert <dougg@torque.net>
Signed-off-by: NJeff Garzik <jgarzik@pobox.com>

No content changes, just moving code around.

Replace SCSI's legacy "bang at the door" method of probing with one
directly controlled by the underlying ATA transport layer.

We now only call scsi_scan_target() for devices we find, rather than
probing every possible channel/id within a certain range.

ATAPI is getting close to being ready.  To increase exposure, we enable
the code in the upstream kernel, but default it to off (present
behavior).  Users must pass atapi_enabled=1 as a module option (if
module) or on the kernel command line (if built in) to turn on
discovery of their ATAPI devices.

- changes license of all code from OSL+GPL to plain ole GPL
  - except for NVIDIA, who hasn't yet responded about sata_nv
  - copyright holders were already contacted privately

- adds info in each driver about where hardware/protocol docs may be
  obtained

- where I have made major contributions, updated copyright dates

- bump versions where necessary
- remove two duplicated+outdated doc comments
- add MODULE_VERSION() to AHCI driver

Also, fixup a tabs-to-spaces block of code in ata_piix.

Authors:
Brett Russ <russb@emc.com>
John W. Linville <linville@tuxdriver.com>
Andy Warner <andyw@pobox.com>

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!