2.6.30 no longer defines WIN_READ, etc., except *outside* of kernel
sources.

In older kernels the ATA_CMD_PIO_* values are present, but in 2.6.9,
for instance, you can't include both hdreg.h and ata.h, so we support
those old kernels by using the WIN_* macros.

commit 04b3ab52a000ab7e718efc97e9fdd67d95002d11
Author: Bartlomiej Zolnierkiewicz &lt;bzolnier@gmail.com&gt;
Date:   Wed Apr 1 21:42:24 2009 +0200

    aoe: WIN_* -&gt; ATA_CMD_*
    
    * Use ATA_CMD_* defines instead of WIN_* ones.
    
    * Include &lt;linux/ata.h&gt; directly instead of through &lt;linux/hdreg.h&gt;.
    
    Cc: Ed L. Cashin &lt;ecashin@coraid.com&gt;
    Signed-off-by: Bartlomiej Zolnierkiewicz &lt;bzolnier@gmail.com&gt;