Re: [Dri-devel] PPC Lockup (ati-pcigart-branch)

Roman Zippel wrote:

Hi,

On Mon, 22 Jan 2001, Dan Malek wrote:

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...I don't know who wrote:

(That was I too :). )

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There is no pte table and so there is nothing mapped at that address,

No, there is a pte table there, you just didn't get to printing
anything from it......

Nope, there is no pte table, otherwise pte had been a valid pointer into
that table, so it's just the offset for that table.

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Err...ahhhh...I don't know if I would go looking in that file for
examples.  I would prefer to understand the problem we are trying to
solve, and perhaps write some functions to call if necessary.  Scattering
code from functions in this file into other places may not be a good
thing.

Sure, one missing information is, how he got that address.

We take the value returned from vmalloc_32 and walk the kernel page
tables from that address.

Anyway, looking up virtual kernel memory that way is possible, with
ioremapped memory it already is dangerous, but for that you also don't get
any page struct.

bye, Roman

Doing this for ioremapped memory would be EVIL.  If your using an
ioremapped area of memory, you should know the addresses it refers too.
I suppose you could get them by walking the page tables, but that's just
icky.  The only reason we are walking the page tables is there is no
kernel call which gives us a list of pages and a virtually contiguous
address.

-Jeff


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