Re: [PATCH](retry 2) Re: invalidate caches before going into suspend

[Arjan van de Ven <arjan@infradead.org>]

On Wed, 13 Aug 2008 13:47:05 -0500
"Langsdorf, Mark" <mark.langsdorf@amd.com> wrote:

> > Mark Langsdorf <mark.langsdorf@amd.com> wrote:
> > > +	/* mask all interrupts, flush any and all caches, and
> > > halt */
> > > +	if (cpu_has_clflush)
> > > +		wbinvd_halt();
> > > +	else
> > > +		while (1)
> > > +			halt();
> > >  }
> > 
> > I like the asm version .. but this code makes me blink.
> > when you HAVE clflush you do wbinvd.
> > yeah I know it's correct but... it reads wonky ;)
> 
> It's the most convenient symbol to test against.  I
> suppose I should add a comment explaining it.
> 
> > also.. can we move that check into the wbinvd_halt() itself, so that
> > the callers don't need to care what is used to select it ?
> 
> irqflags.h doesn't guarantee the presence of boot_cpu_data, 
> so I wasn't able to make that check cleanly.  I could move
> the macro definition to process_??.c if that would better.
> 

it makes sense; it's hardly a hotpath, and making it simple to use
correctly is generally best ;)