[PATCH 1/4] [v4][POWERPC] refactor dcr code

[Benjamin Herrenschmidt]

On Mon, 2008-05-05 at 10:56 -0700, Stephen Neuendorffer wrote:
> Previously, dcr support was configured at compile time to either using
> MMIO or native dcr instructions.  Although this works for most
> platforms, it fails on FPGA platforms:
> 
> 1) Systems may include more than one dcr bus.
> 2) Systems may be native dcr capable and still use memory mapped dcr interface.
> 
> This patch provides runtime support based on the device trees for the
> case where CONFIG_PPC_DCR_MMIO and CONFIG_PPC_DCR_NATIVE are both
> selected.  Previously, this was a poorly defined configuration, which
> happened to provide NATIVE support.  The runtime selection is made
> based on the dcr controller having a 'dcr-access-method' attribute
> in the device tree.  If only one of the above options is selected,
> then the code uses #defines to select only the used code in order to
> avoid introducing overhead in existing usage.
> 
> Signed-off-by: Stephen Neuendorffer <stephen.neuendorffer at xilinx.com>

Quick look seems ok, but that was really only a quick look :-)

I'll rely on Josh to review further.

Cheers,
Ben.