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

Timur Tabi timur.tabi at gmail.com
Tue Nov 16 03:13:58 EST 2010


On Mon, Nov 15, 2010 at 9:16 AM, Kumar Gala <galak at kernel.crashing.org> 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?

-- 
Timur Tabi
Linux kernel developer at Freescale


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