Re: [PATCH v2 03/10] iommupt: Use the incoherent start/stop functions for PT_FEAT_DMA_INCOHERENT

[Jason Gunthorpe <jgg@nvidia.com>]

On Tue, Oct 14, 2025 at 07:51:58AM +0000, Tian, Kevin wrote:
> > From: Jason Gunthorpe <jgg@nvidia.com>
> > Sent: Wednesday, August 27, 2025 1:26 AM
> >
> > +enum alloc_mode {ALLOC_NORMAL, ALLOC_KEEP_INCOHERENT};
> 
> Is it clearer to call it ALLOC_DEFER_FLUSH? I can see what KEEP_INCOHERENT
> means, but only after some thinking. 😊

Lots of things called flush so;

enum alloc_mode {ALLOC_NORMAL, ALLOC_DEFER_COHERENT_FLUSH};

> > @@ -55,6 +55,9 @@ enum {
> >  	PT_ORIG_SUPPORTED_FEATURES = PT_SUPPORTED_FEATURES,
> >  	PT_DEBUG_SUPPORTED_FEATURES =
> >  		UINT_MAX &
> > +		~((PT_ORIG_SUPPORTED_FEATURES &
> > BIT(PT_FEAT_DMA_INCOHERENT) ?
> > +			   0 :
> > +			   BIT(PT_FEAT_DMA_INCOHERENT))) &
> 
> also update the comment that DMA_INCOHERENT can be enabled in
> debug mode only if the fmt supports it.

/*
 * When in debug mode we compile all formats with all features. This allows the
 * kunit to test the full matrix. SIGN_EXTEND can't co-exist with DYNAMIC_TOP or
 * FULL_VA. DMA_INCOHERENT requires a SW bit that not all formats have
 */

Thanks,
Jason