allocating non-cacheable memory

Sangmoon Kim dogoil at
Thu Dec 20 15:57:23 EST 2001

Setting up a BAT by some asembler code is good.
Or you can use io_block_mapping.
For example
io_block_mapping(0x78000000, 0x78000000, 0x08000000, _PAGE_IO);
It maps phisical address 0x78000000 ~ 0x7FFFFFFF to effective address  0x78000000 ~ 0x7FFFFFFF, No cache.
- Sangmoon Kim -

----- Original Message -----
From: "Kevin Fry" <kevin at>
To: <linuxppc-embedded at>
Sent: Thursday, December 20, 2001 10:44 AM
Subject: allocating non-cacheable memory

> What is the best way to allocate some non-cacheable memory for I/O use?
> Right now we are going to setup a BAT table with a non-cacheable memory
> region and use that for all I/O, but does linux have a nice neat
> function to grab a page and set it up non-cacheable for us?
> I was reading in the archives that the #define PAGE_NOCACHE doesn't
> work.
> thanks!
> Kevin

** Sent via the linuxppc-embedded mail list. See

More information about the Linuxppc-embedded mailing list