PTE entries

[Siva Prasad]

Hi Ben,

First, 
Are there any other places where we have self modifying code in Linux
kernel, other than in arch/powerpc/mm/ppc_mmu_32.c:MMU_init_hw()
(basically modified create_hpte and flush_hash_page)

Second,
Instead of using addis, why can't we move it from SDR1 register and mask
the second half. SDR1 has the required value. Right?
May be I am missing something here.

Thanks
- Siva


-----Original Message-----
From: Benjamin Herrenschmidt [mailto:benh at kernel.crashing.org] 
Sent: Tuesday, April 24, 2007 8:50 PM
To: Siva Prasad
Cc: linuxppc-dev at ozlabs.org; linuxppc-embedded at ozlabs.org
Subject: RE: PTE entries

On Tue, 2007-04-24 at 20:34 -0700, Siva Prasad wrote:
> Thanks Ben.
> 
> I managed to fix this. I am working on how best we can rewrite the
self
> modifying code we have for create_hpte routine. I would prefer to read
> from SDR1, than to hardcode (or self modify the code) the way it is
done
> now.
> 
> Feel free to let me know what you think.

Self-modifying allows better performances in that very critical code
path...

Why would you need to change that code anyway ?

Ben.