[PATCH v2 08/11] of: Increase MAX_PHANDLE_ARGS

[will.deacon@arm.com (Will Deacon)]

On Wed, Jan 29, 2014 at 05:57:16PM +0000, Suravee Suthikulanit wrote:
> On 1/29/2014 11:29 AM, Will Deacon wrote:
> > On Wed, Jan 29, 2014 at 05:26:35PM +0000, Suravee Suthikulanit wrote:
> >> On 1/29/2014 11:16 AM, Andreas Herrmann wrote:
> >>> On Wed, Jan 29, 2014 at 11:59:12AM -0500, Suravee Suthikulanit wrote:
> >>>> Actually, we are using 32 on the AMD system. So, do you think we can set
> >>>> this to 32 instead?
> >>>
> >>> I think that's ok.
> >>>
> >>> But are we really talking about number of SMRs or number of StreamIDs
> >>> per master device here? Ie. are you just having 32 SMRs for an SMMU on
> >>> your AMD system or do you have master devices which have 32 StreamIDs?
> >>>
> >>> If it's just number of SMRs we don't need to modify this macro.
> >>>
> >>
> >> I am referring to the case where each mmu-master can have upto 32 streamID.
> >
> > Crikey, how many SMRs do you have? Andreas and I have been struggling to
> > write a decent allocator for those, so if you have any algorithms that don't
> > require a quantum computer, we'd love to hear from you :)!
> >
> > Will
> >
> 
> Are you talking about the __arm_smmu_alloc_bitmap()?
> 
> Currently, we have configured the each SMMU to have 32 SMRs and using 
> 15-bit streamID. However, we mostly have upto 32 streamID for each 
> master, and most of the SMMU only have one master.  So it looks like the 
> current logic should be ok.

Interesting... how does that work for PCI? Do you force all devices behind a
given RC into the same address space?

Will