Re: [PATCH v5 2/6] mm: Add helper to convert HMM pfn to migrate pfn

[Jason Gunthorpe]

On Tue, Mar 17, 2026 at 03:45:09PM +0200, Leon Romanovsky wrote:
> On Tue, Mar 17, 2026 at 03:01:09PM +0200, Mika Penttilä wrote:
> > Hi,
> > 
> > On 3/17/26 11:05, David Hildenbrand (Arm) wrote:
> > 
> > > On 2/11/26 09:12, mpenttil@xxxxxxxxxx wrote:
> > >> From: Mika Penttilä <mpenttil@xxxxxxxxxx>
> > >>
> 
> <...>
> 
> > >>  enum hmm_pfn_flags {
> > >>  	/* Output fields and flags */
> > >> @@ -48,15 +50,25 @@ enum hmm_pfn_flags {
> > >>  	HMM_PFN_P2PDMA     = 1UL << (BITS_PER_LONG - 5),
> > >>  	HMM_PFN_P2PDMA_BUS = 1UL << (BITS_PER_LONG - 6),
> > >>  
> > >> -	HMM_PFN_ORDER_SHIFT = (BITS_PER_LONG - 11),
> > >> +	/* Migrate request */
> > >> +	HMM_PFN_MIGRATE    = 1UL << (BITS_PER_LONG - 7),
> > >> +	HMM_PFN_COMPOUND   = 1UL << (BITS_PER_LONG - 8),
> > >> +	HMM_PFN_ORDER_SHIFT = (BITS_PER_LONG - 13),
> 
> Please don't add fields which are not flags to enum hmm_pfn_flags.

If you are adding a multi-bit field then use GENMASK not shift

Jason