[PATCH 03/14] iommu: Create a base struct for io_mm

[Jordan Crouse]

On Fri, Mar 02, 2018 at 12:25:48PM +0000, Jean-Philippe Brucker wrote:
> Hi Jordan,
> 
> Thank you for this, SMMUv3 and virtio-iommu need these SVA patches as well.
> 
> On 21/02/18 22:59, Jordan Crouse wrote:
> [...]> diff --git a/include/linux/iommu.h b/include/linux/iommu.h
> > index e2c49e583d8d..e998389cf195 100644
> > --- a/include/linux/iommu.h
> > +++ b/include/linux/iommu.h
> > @@ -110,8 +110,17 @@ struct iommu_domain {
> >  	struct list_head mm_list;
> >  };
> >  
> > +enum iommu_io_type {
> > +	IO_TYPE_MM,
> > +};
> > +
> > +struct io_base {
> > +	int type;
> > +	int pasid;
> > +};
> 
> "io_base" is a bit vague. I'm bad at naming so my opinion doesn't hold
> much water, but I'd rather this be something like "io_mm_base". When I
> initially toyed with the idea I intended to keep io_mm as parent structure
> and have "private" and "shared" sub-structures. Even if private PASIDs
> don't rely on the kernel mm subsystem, this structure would still
> represent an I/O mm of sorts, with a pgd and pgtable info.

I'm also bad at naming but I don't mind changing it. io_mm_base seems okay to me
unless somebody has a better idea. I also like the terms "private" and
"shared". I'm going to start adopting those where it makes sense.

Jordan
> 
> > +
> >  struct io_mm {
> > -	int			pasid;
> > +	struct io_base		base;
> >  	struct list_head	devices;
> >  	struct kref		kref;
> >  #if defined(CONFIG_MMU_NOTIFIER)
> > 
> 

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