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>

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

- 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

This patch works around an issue with WD drives (and possibly others)
over SiL PATA->SATA Bridges on SATA controllers locking up with
transfers > 200 sectors.
Signed-off-by: NBrad Campbell <brad@wasp.net.au>

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!