Re: fpu.h

[David Laight <david%l8s.co.uk@localhost>]

On Tue, Feb 18, 2014 at 08:16:36AM +0000, Robert Swindells wrote:
> 
> I think we need a sys/arch/amd64/include/fpu.h that includes x86/fpu.h.

Yes, I'll drop one back in just to keep firefox happy.

> Building firefox fails for me without it.
> 
> I guess a matching file will be needed for i386 too but haven't tried it
> yet.

No, that part of firefox is amd64 only.
The equivalent i386 header was npx.h

It is also making undocumented assumptions about the contents of
some structures.

In fact, since it needs the structures to match the ones the cpu
itself writes when executing fxsave, it could use it's own definition
of the structure itself!

These changes are me harmonising the amd64 and i386 support before adding
kernel support for AVX (saving the ymm registers on context switch).

I had been thinking that getcontext() would need changing.
However the ymm registers are not preserved by function calls,
so I don't think system calls need to preserve them.

Instead the ymm registers can be zeroed on every system call entry,
and they only need saving on interrupt entries.

        David

-- 
David Laight: david%l8s.co.uk@localhost