Re: [RFC 6/7] x86: Move kernel_fpu_using to asm/i387.h

From: Herbert Xu
Date: Wed Jun 17 2009 - 21:49:49 EST


On Wed, Jun 17, 2009 at 10:06:44AM -0700, H. Peter Anvin wrote:
> Ingo Molnar wrote:
> >>
> >> +static inline int kernel_fpu_using(void)
> >> +{
> >> + if (in_interrupt() && !(read_cr0() & X86_CR0_TS))
> >> + return 1;
> >> + return 0;
> >> +}
> >> +
> >
> > Looks sane to me. Herbert, do you ack it?

Ack. Please pick it up in your tree. Thanks!

> Huang: if I recall correctly, these functions were originally designed
> to deal with the fact that VIA processors generate spurious #TS faults
> due to broken design of the Padlock instructions. The AES and PCLMUL
> instructions actually use SSE registers and so will require different
> structure.

No irq_ts_save was the one designed for the VIA, the Intel stuff
does save the FPU state.

Cheers,
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