[intel-platform-discuss] Intel Platform optimised software crypto algorithms

[Darren J Moffat]

David Edmondson wrote:
> On Thu, Mar 15, 2007 at 01:48:53PM +0000, Darren J Moffat wrote:
>> All the algorithms listed above are build for userland and kernel
>> from the same algorithm source code but with slightly different
>> "plumbing".
> 
> What are the restrictions on using (say) SSE instructions in the
> kernel?

The current 32 bit x86 BIGNUM code uses SSE and does so in the kernel by 
disabling preemption around the instructions that use it.  We also save 
and restore some register state.

http://src.opensolaris.org/source/xref/onnv/onnv-gate/usr/src/common/bignum/i386/bignum_i386_asm.s#110

That code was written by Guy Shaw who I believe is now working in Sun 
labs on the PPC port.


-- 
Darren J Moffat