* allocating non-cacheable memory
@ 2001-12-20 1:44 Kevin Fry
2001-12-20 2:17 ` Dan Malek
2001-12-20 4:57 ` Sangmoon Kim
0 siblings, 2 replies; 3+ messages in thread
From: Kevin Fry @ 2001-12-20 1:44 UTC (permalink / raw)
To: linuxppc-embedded
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
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^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: allocating non-cacheable memory
2001-12-20 1:44 allocating non-cacheable memory Kevin Fry
@ 2001-12-20 2:17 ` Dan Malek
2001-12-20 4:57 ` Sangmoon Kim
1 sibling, 0 replies; 3+ messages in thread
From: Dan Malek @ 2001-12-20 2:17 UTC (permalink / raw)
To: Kevin Fry; +Cc: linuxppc-embedded
Kevin Fry wrote:
> 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
If you have a processor with BAT, why do you need non-cached memory?
-- Dan
** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: allocating non-cacheable memory
2001-12-20 1:44 allocating non-cacheable memory Kevin Fry
2001-12-20 2:17 ` Dan Malek
@ 2001-12-20 4:57 ` Sangmoon Kim
1 sibling, 0 replies; 3+ messages in thread
From: Sangmoon Kim @ 2001-12-20 4:57 UTC (permalink / raw)
To: linuxppc-embedded
Hi
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@carts.com>
To: <linuxppc-embedded@lists.linuxppc.org>
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 http://lists.linuxppc.org/
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2001-12-20 1:44 allocating non-cacheable memory Kevin Fry
2001-12-20 2:17 ` Dan Malek
2001-12-20 4:57 ` Sangmoon Kim
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