On Mon, Apr 04, 2005 at 08:59:03AM -0500, James Bottomley wrote:
> Well ... it's like this. Native means "pass through without swapping"
> and has an easy implementation on both BE and LE platforms. Logically
> io{read,write}{16,32}be would have to do byte swaps on LE platforms.
> Being lazy, I'm opposed to doing the work if there's no actual use for
> it, so can you provide an example of a BE bus (or device) used on a LE
> platform that would actually benefit from this abstraction?
The IOC4 device that provides IDE, serial ports and external interrupts
on Altix systems has a big endian register layour, and the PCI-X bridge
in those Altix systems can do the swapping if a special bit is set.
In older kernels that bit was set from the driver through a special API,
but it seems the firmware does that automatically now.
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
