On Monday 07 April 2008 20:11:28 David Gibson wrote:
> On Mon, Apr 07, 2008 at 03:53:33PM -0500, Hollis Blanchard wrote:
> > 1 file changed, 7 insertions(+)
> > include/linux/kvm.h | 7 +++++++
> >
> >
> > Device Control Registers are essentially another address space found on
> > PowerPC 4xx processors, analogous to PIO on x86. DCRs are always 32 bits,
> > and are identified by a 32-bit number.
>
> Well... 10-bit, actually.
The mtdcrux description in the ppc440x6 user manual says the following:
Let the contents of register RA denote a Device Control Register.
The contents of GPR[RS] are placed into the designated Device Control
Register.
I take that to mean that we must worry about 32 bits worth of DCR numbers.
Perhaps I should say "no more than" rather than "always".
--
Hollis Blanchard
IBM Linux Technology Center
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