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Date: Mon, 17 Oct 2016 19:02:19 +0200 (CEST)
From: Thomas Gleixner <tglx@linutronix.de>
To: Fenghua Yu <fenghua.yu@intel.com>
cc: "H. Peter Anvin" <h.peter.anvin@intel.com>,
        Ingo Molnar <mingo@elte.hu>, Tony Luck <tony.luck@intel.com>,
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        Vikas Shivappa <vikas.shivappa@linux.intel.com>,
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Subject: Re: [PATCH v4 08/18] x86/intel_rdt: Pick up L3/L2 RDT parameters
 from CPUID
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On Mon, 17 Oct 2016, Fenghua Yu wrote:
> On Mon, Oct 17, 2016 at 03:45:32PM +0200, Thomas Gleixner wrote:
> > I wonder whether this is the proper abstraction level. We might as well do
> > the following:
> > 
> > rdtresources[] = {
> >      {
> > 	.name	= "L3",
> >      },
> >      {
> > 	.name	= "L3Data",
> >      },
> >      {
> > 	.name	= "L3Code",
> >      },
> > 
> > and enable either L3 or L3Data+L3Code. Not sure if that makes things
> > simpler, but it's definitely worth a thought or two.
> 
> This way will be better than having cdp_enabled/capable for L3 and not
> for L2.

So you need to change the struct to have capable and enabled

> > static void rdt_get_config(int idx, struct rdt_resource *r)
> > {
> > 	union cpuid_0x10_1_eax eax;
> > 	union cpuid_0x10_1_edx edx;
> > 	u32 ebx, ecx;
> > 
> > 	cpuid_count(0x00000010, idx, &eax.full, &ebx, &ecx, &edx.full);
> > 	r->max_closid = edx.split.cos_max + 1;
> > 	r->num_closid = r->max_closid;
> > 	r->cbm_len = eax.split.cbm_len + 1;
> > 	r->max_cbm = BIT_MASK(eax.split.cbm_len + 1) - 1;
> > 	r->enabled = true;

And set 

    	r->capable = true; 

here instead of r->enabled and set r->enabled at mount time for the
resources depending on the mount flags.

Thanks,

	tglx