Re: [PATCH v2] fsldma: add support to 36-bit physical address

From: Kumar Gala
Date: Mon Nov 15 2010 - 12:43:46 EST



On Nov 15, 2010, at 10:13 AM, Timur Tabi wrote:

> On Mon, Nov 15, 2010 at 9:16 AM, Kumar Gala <galak@xxxxxxxxxxxxxxxxxxx> wrote:
>
>> The programming model (if you look at the free-space in the registers and data structures) supports a 64-bit address. I'm trying to avoid changing the driver in the future if we have >36-bit. However this is such a minor worry that I'll stop and just ack the patch as is.
>
> I must still be missing something. I'm looking at the description of
> the SATR register in the MPC8572 RM, and it shows this:
>
> 0 - 3 | 4 - 5 | 6 | 7 | 8 - 11 | 12 - 15 | 16-21 | 22-31
> --- | STFLOWLVL | SPCIORDER | SSME | STRANSINT | SREADTTYPE | --- | ESAD
>
> The most that we can extend ESAD to is 16 bits, for a total of a
> 48-bit physical address. Where are the other 16 bits supposed to go?

I was looking at the link addresses. I stand corrected so our max is 48-bits.

- k--
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