Re: [PATCH 03 of 36] x86: add memory barriers to wrmsr

Arjan van de Ven
2008-06-25T22:32:08Z

On Wed, 25 Jun 2008 14:08:57 -0700
Jeremy Fitzhardinge <jeremy@goop.org> wrote:

> Arjan van de Ven wrote:
> > it's more readable for several of these cases to stick a barrier();
> > in front and after it to be honest; that makes it more explicit that
> > these are deliberate compiler barriers rather than "actual" memory
> > access...
> >
> >
>
> I suppose, though I would be inclined to put the barriers in the
> wrmsr macro itself to act as documentation.

yeah I meant like this:

static inline void native_write_msr(unsigned int msr,
unsigned low, unsigned high)
{
barrier();
asm volatile("wrmsr" : : "c" (msr), "a"(low), "d" (high));
barrier();
}

or in the same in the thing that calls this.

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